ARTICLE | doi:10.20944/preprints202306.0199.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: mutations; folding free energy change; binding free energy change; single nucleotide variant
Online: 2 June 2023 (11:58:21 CEST)
Development of methods and algorithms to predict the effect of mutations on protein stability, protein-protein, and protein-DNA/RNA binding is necessitated by the needs of protein engineering and for understanding the molecular mechanism of disease-causing variants. The vast majority of the leading methods are either methods with adjustable parameters or machine learning algorithms, both requiring a database of experimentally measured folding and binding free energy changes. These databases are collections of experimental data taken from scientific investigations typically aimed at probing the role of particular residue on the above-mentioned thermodynamics characteristics, i.e., the mutations are not introduced at random and do not necessarily represent mutations originating from single nucleotide variant (SNV). Thus, the reported performance of the leading algorithms assessed on these databases or other limited cases, may not be applicable for predicting the effect of SNVs seen in the human population. Indeed, we demonstrate that the SNVs and non-SNVs are not equally presented in the corresponding databases and the distribution of the free energy changes are not the same. Furthermore, the Pearson correlation coefficients (PCCs) obtained on cases involving SNVs are less impressive than for non-SNVs, indicating that caution should be used in applying them to reveal the effect of human SNVs. All methods are found to underestimate the energy changes by roughly a factor of 2.
ARTICLE | doi:10.20944/preprints202306.0195.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Male infertility; heavy smoking; transcript level; PGAM5; PTPRN2; TYRO3
Online: 2 June 2023 (11:49:29 CEST)
Smoking have been linked to male infertility by affecting the sperm epigenome and genome. In this study, we aimed to determine possible changes in the transcript levels of the PTPRN2, PGAM5, and TYRO3 genes in heavy smokers compared with non-smokers; and to investigate their association with fundamental sperm parameters. One hundred eighteen sperm samples (63 heavy-smokers (G1) and 55 non-smokers (G2) were included in this study. Semen analysis was performed according to WHO guidelines. After total RNA extraction, RT-PCR was used to quantify the transcript levels of studied genes. In G1 a significant decrease in standard semen parameters in comparison to non-smokers has been shown (p<0.05). Moreover, PGAM5 and PTPRN2 were differentially expressed (P≤0.03 and P≤0.01, respectively), and downregulated in spermatozoa of G1 compared to G2. In contrast, no difference was observed for TYRO3 (p≤0.3). In G1, mRNA expression level of studied genes correlated negatively with motility, sperm count, normal form, vitality, and sperm membrane integrity (p<0.05). Therefore, smoking may affect gene expression and male fertility by altering DNA methylation patterns in genes associated with fertility and sperm quality, including PGAM5, PTPRN2, and TYRO3.
REVIEW | doi:10.20944/preprints202306.0128.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: PD-L1; CTCs; immunotherapy; immune checkpoint inhibitors
Online: 2 June 2023 (04:28:01 CEST)
The approval of monoclonal antibodies against programmed death-ligand 1 (PD-L1) and programmed cell death protein (PD1), has changed the landscape of cancer treatment. To date, many Immune Checkpoint Inhibitors (ICIs) have been approved by the FDA for the treatment of metastatic cancer as well as locally recurrent advanced cancer. However, immune-related adverse events (irAEs) of ICIs highlight the need for biomarker analysis with strong predictive value. Liquid biopsy is an important tool for clinical oncologists to monitor cancer patients and administer or change appropriate therapy. CTCs frequently express PD-L1 and this constitutes a clinically useful and non-invasive method to assess PD-L1 status in real time. This review summarizes all the latest findings about the clinical significance of CTC for the management of cancer patients during administration of immunotherapy and mainly focuses on the assessment of PD-L1 expression in CTCs.
ARTICLE | doi:10.20944/preprints202305.2052.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: methyl-CpG; DNA methylation; gene expression; cell identity
Online: 2 June 2023 (04:15:42 CEST)
Cell identity is determined by chromatin structure and the profiles of gene expression, which are dependent on chromatin accessibility and DNA methylation of regions critical for gene expression, such as enhancers and promoters. These epigenetic modifications are required for mammalian development and are essential for the establishment and the maintenance of the cellular identity. DNA methylation was once thought to be a permanent repressive epigenetic mark, but systematic analysis in various genomic contexts reveals a more dynamic regulation than previously thought. In fact, both active DNA methylation and demethylation occur during cell fate commitment and terminal differentiation. To link methylation signatures of specific genes to their expression profiles, we have determined the methyl-CpG configurations of the promoters of five genes switched on and off during murine postnatal brain differentiation by bisulfite-targeted sequencing. We report here the structure of significant, dynamic and stable methyl-CpG profiles associated with silencing or activation of expression of genes during neural stem cell and brain postnatal differentiation. Strikingly, these methylation cores mark different mouse brain areas and cell types derived from the same areas during differentiation.
ARTICLE | doi:10.20944/preprints202306.0096.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: depressive-like behavior; prefrontal cortex; fluoxetine; metabolomics; ROC curve; support vector machine-linear kernel
Online: 1 June 2023 (13:35:47 CEST)
The increasing prevalence of depression worldwide requires more effectiveness in therapy approaches and a molecular understanding of antidepressants mode of action. We carried out untargeted metabolomics of the prefrontal cortex of rats exposed to chronic social isolation (CSIS), a rat model of depression, and/or fluoxetine treatment using liquid chromatography-high resolution mass spectrometry. The behavioral phenotype was assessed by the forced swim test. To analyze metabolomics data, univariate and multivariate analysis and biomarker capacity assessment using the classical receiver operating characteristic (ROC) curve were used. Support vector machine-linear kernel (SVM-LK), as a machine-learning algorithm was performed for binary classification. Upregulated myo-inositol following CSIS may represent a potential marker of depressive phenotype. Effective fluoxetine treatment reversed depressive-like behavior and increased sedoheptulose 7-phosphate, hypotaurine, and acetyl-L-carnitine contents, which were identified as potential markers. We identified 4 or 10 marker candidates with ROC curve greater than 0.9 for CSIS or fluoxetine effectiveness designation. SVM-LK has given accuracy of 61.50%, or 93.30%, and 7 or 25 predictive metabolites for CSIS vs. control and fluoxetine-treated CSIS vs. CSIS classification. Overall, metabolic fingerprints combined with ROC curve and SVM-LK may represent a new approach to identifying potential markers or predicting metabolites for group designation or classification.
REVIEW | doi:10.20944/preprints202306.0070.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Collagen Cross-linking; Extracellular Matrix; Fibrosis; Glycation; Lysyl Oxidase; Polyphenols
Online: 1 June 2023 (08:46:00 CEST)
Collagen, the most abundant structural protein found in mammals, plays a vital role as a constituent of the extracellular matrix (ECM) that surrounds cells. Collagen fibrils are strengthened through the formation of covalent cross-links, which involve complex enzymatic and non-enzymatic reactions. Lysyl oxidase (LOX) is responsible for catalyzing the oxidative deamination of lysine and hydroxylysine residues, resulting in the production of aldehydes, allysine, and hydroxyallysine. These intermediates undergo spontaneous condensation reactions, leading to the formation of immature cross-links, which are the initial step in the development of mature covalent cross-links. Additionally, non-enzymatic glycation contributes to the formation of abnormal cross-linking in collagen fibrils. During glycation, specific lysine and arginine residues in collagen are modified by reducing sugars, leading to the creation of Advanced Glycation End-products (AGEs). These AGEs have been associated with changes in the mechanical properties of collagen fibers. Interestingly, various studies have reported that plant polyphenols possess amine oxidase-like activity and can act as potent inhibitors of protein glycation. This review article focuses on compiling literature describing polyphenols with amine oxidase-like activity and antiglycation properties. Specifically, we explore the molecular mechanisms by which specific flavonoids impact or protect the normal collagen cross-linking process. Furthermore, we discuss how these dual activities can be harnessed to generate properly cross-linked collagen molecules, thereby promoting the stabilization of highly organized collagen fibrils.
REVIEW | doi:10.20944/preprints202306.0066.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Systems Biology; Multiomics; Cryptosporidium; Giardia; Entamoeba; Anti-Microbial Resistance; Multi Drug Resistance; Probiotic; Prebiotics, Synbiotics; Postbiotics
Online: 1 June 2023 (08:29:21 CEST)
Enteric protozoan pathogenic infections significantly contribute to the global burden of gastrointestinal illnesses. Their occurrence is considerable within remote and indigenous communities and regions due to reduced access to clean water and adequate sanitation. The robustness of these pathogens means requirement of harsh treatment methods such as medicinal drugs or antibiotics. However, such treatments impact the gut microbiome, and create dysbiosis, often leading to opportunistic pathogens, anti-microbial resistance, or functional gastrointestinal disorders (FGIDs) such as irritable bowel syndrome (IBS). Recent studies have shown that these impacts do not remain confined to gut, and are reflected across the gut-brain, gut-liver, and gut-lung axes, among others. Therefore, apart from the medicinal treatment, nutritional supplementation is also a key aspect of providing the recovery from this dysbiosis. Future proteins, prebiotics, probiotics, synbiotics, and food formulations offer a good solution to remedy this dysbiosis. Furthermore, the nutritional supplementation also helps to build a resilience against the opportunistic pathogens and potential future infections and disorders that may arise due to the dysbiosis. Systems biology techniques have shown to be highly effective tools to understand the biochemistry of these processes. Systems biology techniques characterises the fundamental host-pathogen interaction biochemical pathways, at various infection and recovery stages. This same mechanism also allows to track the impact of abovementioned treatment methods of gut microbiome remediation. This manuscript is organised in sections delving into system biology approaches and upcoming developments to understand (1) Infection mechanism and current global status; (2) Cross-organ impacts of dysbiosis, particularly within gut-liver and gut-lung axes; (3) Nutritional interventions. It highlights the impact of antimicrobial resistance (AMR) and Multi-drug resistance (MDR) from a perspective of protozoal infections. It also highlights the role of nutritional interventions to add resilience against the chronic problems caused by these phenomena.
REVIEW | doi:10.20944/preprints202306.0045.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: miRNAs; Cancer; oncomiRs; tumor suppressor miRNAs; biomarker; therapeutics
Online: 1 June 2023 (07:20:49 CEST)
MicroRNAs (miRNAs) are single-stranded, noncoding RNA molecules that regulate gene expression post-transcriptionally by binding to messenger RNAs. miRNAs are important regulators of gene expression, and their dysregulation is implicated in many human and dog diseases. Most cancers tested, to date, have been shown to express altered miRNA levels, which indicates their potential importance in the oncogenic process. Based on this evidence, numerous miRNAs have been suggested as potential cancer biomarkers for both diagnosis and prognosis. miRNA-based therapies have also been tested in different cancers and have provided measurable clinical benefits to patients. In addition, understanding miRNA biogenesis and regulatory mechanisms in cancer can provide important knowledge about resistance to chemotherapies, leading to more personalized cancer treatment. In this review, we have comprehensively summarized the importance of miRNA in human and dog cancer research. We have discussed the current state of development and potential for miRNA as both a diagnostic marker and a therapeutic target.
REVIEW | doi:10.20944/preprints202306.0041.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: APE1; inhibitors; cancer.
Online: 1 June 2023 (07:05:48 CEST)
APE1 is an essential endodeoxyribonuclease of the base excision repair pathway that maintains genome stability. It was identified as a pivotal factor favoring tumor progression and chemo-resistance through the control of gene expression by a redox-based mechanism. APE1 is overex-pressed and serum-secreted in different cancers, representing a prognostic and predictive factor, and a promising non-invasive biomarker. Strategies directly targeting APE1 funtions led to the identification of inhibitors showing a potential therapeutic value, which some of them are cur-rently in clinical trials. Interestingly, evidence indicates novel roles of APE1 in RNA metabolism still not fully understood, including its activity in processing damaged RNA in chemoresistant phenotypes, regulating oncomiRs maturation, and oxidized-RNA decay. Recent data point out a control role of APE1 in the expression and sorting of oncomiRs, within secreted extracellular vesicles (EVs). This review is focused on giving a portrait of the pros and cons of the last two decades of research aiming at the identification of inhibitors of the redox or the DNA-repair functions of APE1 for the definition of novel targeted therapies for cancer. We will discuss the new perspectives in cancer therapy coming from the unexpected finding of the APE1 role in miRNA processing for personalized therapy.
ARTICLE | doi:10.20944/preprints202305.2204.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Linked; marker association; annotation; Genes
Online: 31 May 2023 (08:41:16 CEST)
Shea tree (Vitellaria paradoxa) is an important fruit tree crop because of its oil used for cooking and industrial manufacture of cosmetics. Despite its many benefits, quantitative trait loci linked to the economic traits have not yet been studied. In this study, we performed association mapping on a panel of 374 shea tree accessions using 7,530 single-nucleotide polymorphisms (SNPs) markers for oil yield and seed related traits. Twenty three markers that were significantly (–log10 (p) = 4.87) associated to kernel oil content, kernel length; width and weight were identified. The kernel dry matter oil content and kernel width had the most significant Marker Trait Association (MTA) on chromosomes 1 and 8 respectively. Sixteen candidate genes that condition early induction of flower buds and somatic embryos, seed growth and development, substrate binding, transport, lipid biosynthesis, metabolic processes during seed germination and disease resistance and abiotic stress adaptation were identified. The presence of these genes suggest their role in promoting shea bioactive functions that condition high oil synthesis. This study provides insights into the important marker-linked seed traits with genes controlling them, useful for molecular breeding for improving oil yield in the species.
ARTICLE | doi:10.20944/preprints202305.2202.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Heortia vitessoides Moore; Chitin synthase B gene; RNA interference; Starvation; Refeeding
Online: 31 May 2023 (08:36:19 CEST)
The chitin synthase B gene is a key enzyme in the chitin synthesis of insect peritrophic matrix (PM), affecting insects' feeding behavior. The chitin synthase B gene has been cloned from the transcription library of Heortia vitessoides Moore. RT-qPCR showed that HvChsb was highly expressed in the larval stage of H. vitessoides, especially on the first day of the prepupal stage, and in the midgut of larvae and the abdomen of adults. After starvation treatment, HvChsb was found to be significantly inhibited with time. After 48 h of starvation, the feeding experiment showed that HvChsb increased with the prolongation of the refeeding time. The experimental data showed that feeding affected the expression of HvChsb. HvChsb was effectively silenced by RNA interference, so its function was lost, significantly decreasing the survival rate of H. vitessoides. The survival rate from larval-to-pupal stages was only 43.33%, accompanied by abnormal phenotypes. It can be seen that HvChsb plays a key role in the average growth and development of H. vitessoides.
REVIEW | doi:10.20944/preprints202305.2170.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: DNA damage; base excision repair; nucleotide excision repair; UV-DDB; chromatin; nucleosome; DNA glycosylases; single molecule; cell biology; biochemistry
Online: 31 May 2023 (05:44:02 CEST)
Base excision repair (BER) is a cellular process that removes damaged bases arising from exogenous and endogenous sources including reactive oxygen species, alkylation agents, and ionizing radiation. BER is mediated by the actions of multiple proteins that work in a highly concerted manner to resolve DNA damage efficiently to prevent toxic repair intermediates. During the initiation of BER, the damaged base is removed by one of 11 mammalian DNA glycosylases resulting in abasic sites. Many DNA glycosylases are product inhibited by binding to the abasic site more avidly than the damaged base. Traditionally apurinic/apyrimidinic endonuclease, APE1, was believed to help turnover the glycosylases to undergo multiple rounds of damaged base removal. However, in a series of papers from our laboratory we have demonstrated that UV-damaged DNA binding protein (UV-DDB) stimulates the glycosylase activities of human 8-oxoguanine glycosylase (OGG1), MUTY DNA glycosylase (MUTYH), alkyladenine glycosylase/N-methylpurine DNA glycosylase (AAG/MPG), and single-strand selective monofunctional glycosylase (SMUG1), between three-to-five-fold. Moreover, we have shown UV-DDB can assist chromatin decompaction facilitating access of OGG1 to 8-oxoguanine damage in telomeres. This review summarizes the biochemistry, single-molecule, and cell biology approaches that our group used to directly demonstrate the essential role of UV-DDB in BER.
REVIEW | doi:10.20944/preprints202305.2171.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: caffeic acid phenethyl ester; CAPE derivatives; anti-inflammatory; NF-kB; antioxidant; Nrf2; neuroprotection
Online: 31 May 2023 (05:32:19 CEST)
Neurodegenerative disorders are characterized by a progressive process of degeneration and neuronal death, where oxidative stress and neuroinflammation are key factors that contribute to the progression of these diseases. Therefore, two major pathways involved in these pathologies have been proposed as relevant therapeutic targets: The nuclear transcription factor erythroid 2 (Nrf2), which responds to oxidative stress with cytoprotecting activity and the nuclear factor NF-κB pathway, which is highly related to the neuroinflammatory process by promoting cytokine expression. Caffeic acid phenethyl ester (CAPE) is a phenylpropanoid naturally found in propolis that shows important biological activities, including neuroprotective activity by modulating the Nrf2 and NF-kB pathways, promoting antioxidant enzyme expression and inhibition of proinflammatory cytokine expression. Its simple chemical structure has inspired the synthesis of many derivatives, with aliphatic and/or aromatic moieties, some of which have improved the biological properties. Moreover, new drug delivery systems increase the bioavailability of these compounds in vivo, allowing its transcytosis through the blood-brain barrier, thus protecting brain cells from the increased inflammatory status associated to neurodegenerative and psychiatric disorders. This review summarizes the biosynthesis and chemical synthesis of CAPE derivatives, their miscellaneous activities, and relevant studies (from 2010 to 2023) addressing their neuroprotective activity in vitro and in vivo.
ARTICLE | doi:10.20944/preprints202305.2084.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: urinary extracellular vesicles,; exosomes; urine; diabetic kidney disease; reference genes; miRNA; mRNA; sequencing
Online: 30 May 2023 (08:23:23 CEST)
Urinary extracellular vesicles (uEV) hold non-invasive RNA biomarkers for genitourinary tract diseases. However, missing knowledge about reference genes and effects of pre-analytical choices hinder biomarker studies. We aimed to assess how pre-analytical variables (urine storage temperature, isolation workflow) affect diabetic kidney disease (DKD) -linked miRNAs or kidney -linked miRNAs and mRNAs (kidney-RNAs) in uEV isolates and to discover stable reference mRNAs across diverse uEV datasets. We studied nine raw and normalized sequencing datasets including healthy controls and individuals with prostate cancer or type 1 diabetes with or without albuminuria. We focused on kidney-RNAs reviewing literature for DKD-linked miRNAs from kidney tissue, cell culture and uEV/urine experiments. RNAs were analyzed by expression heatmaps, hierarchical clustering and selecting stable mRNAs with normalized counts (>200) and minimal coefficient of variation. Kidney-RNAs were decreased after urine storage at -20°C vs -80°C. Isolation workflows captured kidney-RNAs with different efficiencies. Ultracentrifugation captured DKD -linked miRNAs that separated healthy and diabetic macroalbuminuria groups. Eleven mRNAs were stably expressed across the datasets. Hence, preanalytical choices had variable effects on kidney-RNAs – analyzing kidney-RNAs complemented global correlation, which could fade differences in some relevant RNAs. Replicating prior DKD-marker results and discovery of candidate reference mRNAs encourages further uEV biomarker studies.
ARTICLE | doi:10.20944/preprints202305.2067.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Metagenomics; red algae; microbial diversity; algal-polysaccharide-degrading enzymes
Online: 30 May 2023 (07:33:37 CEST)
Macroalgae and macroalgae-associated bacteria together constitute the most efficient metabolic cycling system in the ocean. Their interactions, especially the responses of macroalgae-associated bacteria communities to algae in different geographical locations, is mostly unknown. In this study, metagenomics was used to analyze the microbial diversity and associated algal polysaccharide-degrading enzymes on the surface of red algae among three remote regions. There were significant differences in the macroalgae-associated bacteria community composition and diversity among the different regions. At the phylum level, Proteobacteria, Bacteroidetes, and Actinobacteria had a significantly high relative abundance among the regions. From the perspective of species diversity, samples from China had the highest macroalgae-associated bacteria diversity, followed by those from Antarctica and Indonesia. In addition, in the functional prediction of the bacterial community, genes associated with amino acid metabolism, carbohydrate metabolism, energy metabolism, metabolism of cofactors and vitamins, and membrane transport had a high relative abundance. Canonical correspondence analysis and redundancy analysis of environmental factors showed that, without considering algae species and composition, pH and temperature were the main environmental factors affecting bacterial community structure. Furthermore, there were significant differences in algal polysaccharide-degrading enzymes among the regions. Samples from China and Antarctica had high abundances of algal polysaccharide-degrading enzymes, while those from Indonesia had extremely low abundances. The environmental differences between these three regions may impose a strong geographic differentiation regarding the biodiversity of algal microbiomes and their expressed enzyme genes. This work expands our knowledge of algal microbial ecology, and contributes to an in-depth study of their metabolic characteristics, ecological functions, and applications.
ARTICLE | doi:10.20944/preprints202305.2047.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: CDC20; BIOMARKER; KMT5A; p53; prostate cancer
Online: 30 May 2023 (05:03:54 CEST)
The methyltransferase, KMT5A has been proposed as an oncogene in prostate cancer and therefore represents a putative therapeutic target. To confirm this hypothesis we have performed a microarray study in a prostate cancer cell line model of androgen independence following KMT5A knockdown in the presence of transcriptionally active androgen receptor (AR) to understand which genes and cellular processes are regulated by KMT5A in the presence of an active AR. We observed that 301 genes were down-regulated whilst 408 were up-regulated when KMT5A expression was reduced. KEGG pathway and Gene Ontology analysis revealed apoptosis and DNA damage signaling are up-regulated in response to KMT5A knockdown whilst protein folding and RNA splicing were down-regulated. Under these conditions, the top non-AR regulated gene was found to be CDC20, a key regulator of the spindle assembly checkpoint with an oncogenic role in several cancer types. Further investigation revealed that KMT5A regulates CDC20 in a methyltransferase dependent manner to modulate both histone H4K20 methylation within its promoter region and indirectly via the p53 signalling pathway. A positive correlation between KMT5A and CDC20 expression was also observed in clinical prostate cancer samples further supporting this association. Therefore, we conclude that KMT5A is a valid therapeutic target for the treatment of prostate cancer and CDC20 could potentially be utilized as a biomarker for effective therapeutic targeting.
CASE REPORT | doi:10.20944/preprints202305.2038.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Familial hypercholesterolemia; Next Generation Sequencing; LDL-cholesterol; LDLR gene; Copy number variations (CNVs); Alu sequences
Online: 30 May 2023 (04:25:02 CEST)
Next Generation Sequencing (NGS), now widely used in the clinical setting, offers an efficient and comprehensive molecular approach for patients with Familial hypercholesterolemia (FH). Although the dominant form of disease is mostly due to low-density lipoprotein receptor (LDLR) small-scale pathogenic variants, approximately 10% of molecularly defined FH cases are due to Copy Number Variations (CNVs). Here, we report a novel large deletion of the LDLR gene involving exons 4–18, identified by bioinformatic analysis of NGS data in an Italian family. A long PCR strategy was employed for breakpoint region analysis where an insertion of 6 nucleotides (TTCACT) was found. Two Alu sequences, identified within intron 3 and exon 18, could underlie the identified rearrangement by a Nonallelic Homologous Recombination (NAHR) mechanism. NGS proves to be a powerful tool used to precisely identify CNVs, in addition to small-scale variants in FH-related genes. At this purpose, the use and implementation of this cost-effective, efficient molecular approach meets the clinical need for personalized diagnosis in FH cases.
ARTICLE | doi:10.20944/preprints202305.2032.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Hep-G2 hepatocarcinoma cell; Deuterium-depleted water; Deuterium-enriched water; Cyclooxygenase inhibitors; MAPK pathway; Apoptosis
Online: 30 May 2023 (04:02:57 CEST)
Hepatocellular carcinoma (HCC) is the most common form of liver cancer worldwide. Accumulating clinical and experimental evidence suggests the role of cyclo-oxygenase (COX) enzymes in the pathogenesis of cancers including HCC. Deuterium-enriched water (DEW) and deuterium-depleted water (DDW) play a role both in the treatment and prevention of cancers. Combination therapy using COX-inhibitors and DDW/DEW could be a rational strategy to enhance the cytotoxicity of either agent in HCC. The cytotoxicity of celecoxib or indomethacin, alone and in combination with DDW or DEW was determined in the Hep-G2 HCC cell line by MTT assay. The COX-2, MAPK pathway proteins, the anti-apoptotic Bcl2 and pro-apoptotic Bax proteins, and caspase-3 activity were determined by SDS-PAGE and western blot. Co-treatment of selective and non-selective COX-2 inhibitors with DEW led to a remarkable increase in cytotoxicity and apoptosis of Hep-G2 cells. These events were associated with the activation of p38 and JNK MAPKs and a decrease in pro-survival proteins Bcl-2, COX-2, and ERK1/2. Furthermore, the combination therapy activated caspase-3, and the apoptosis mediator, and disabled poly ADP-ribose polymerase (PARP), the key DNA repair enzyme, by cleaving it. The combination of DEW with NSAIDs might be effective against HCC cells by influencing principal cell signaling pathways, and this has a potential to become a candidate for chemotherapy.
ARTICLE | doi:10.20944/preprints202305.2003.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: neurodegeneration; microglia; inflammation; neuroprotection; trace-amine associated receptors type 1 (TAAR1); 3-iodothyronamine
Online: 29 May 2023 (09:35:35 CEST)
Microglial dysfunction is one of the hallmarks and leading causes of common neurodegenerative diseases (NDD), including Alzheimer’s disease (AD) and Parkinson’s disease (PD). All these pathologies are characterized by aberrant aggregation of disease-causing proteins in the brain, which can directly activate microglia, trigger microglia-mediated neuroinflammation, and increase oxidative stress. Inhibition of glial activation may represent a therapeutic target to alleviate neurodegeneration. Recently, 3-iodothyronamine (T1AM), an endogenous derivative of thyroid hormone (TH) able to interact directly with a specific GPCR known as trace amine-associated receptor 1 (TAAR1), gained interest for its ability to promote neuroprotection in several models. Nevertheless, T1AM’s effects on microglial disfunction remain still elusive. In the present work we investigated whether T1AM could inhibit the inflammatory response of human HMC3 microglial cells to LPS/TNFα or β-amyloid peptide 25-35 (Aβ25-35) stimuli. The results of ELISA and qPCR assays revealed that T1AM was able to reduce microglia-mediate inflammatory response by inhibiting the release of proinflammatory factors, including IL-6, TNFα, NF-kB, MCP1 and MIP1, while promoting the release of anti-inflammatory mediators, such as IL-10. Notably, T1AM anti-inflammatory action in HMC3 cells resulted to be a TAAR1-mediated response, further increasing the relevance of the T1AM/TAAR1 system in the management of NDD.
ARTICLE | doi:10.20944/preprints202305.1976.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: hepatocellular carcinoma (HCC); CD4+ T cells; next generation sequencing (NGS); long non-coding RNAs (lncRNAs); microRNAs (miRNAs)
Online: 29 May 2023 (05:23:24 CEST)
Hepatocellular carcinoma (HCC) is one of the most common cancers and the main cause of cancer-related death globally. Immune dysregulation of CD4+ T cells has been identified as a role in the development of HCC. Nevertheless, the underlying molecular pathways of CD4+ T cells in HCC are not completely known. Thus, a better understanding of the dysregulation of lncRNA-miRNA/mRNA network might yield novel insights into the etiology or progression of HCC. In this study, circulating CD4+ T cells were isolated from the whole blood of 10 healthy controls and 10 HCC patients for next-generation sequencing of the expression of lncRNAs, miRNAs, and mRNAs. Our data showed that there was different expression of 34 transcripts (two lncRNAs, XIST and MIR222HG, 29 mRNA, and 3 other types of RNA) and 13 miRNAs in the circulating CD4+ T cells of HCC patients. The expression of the lncRNA XIST-related miRNAs and their target mRNAs was confirmed using real-time quantitative polymerase chain reaction (qPCR) on samples from 100 healthy controls and 60 HCC patients. The lncRNA–miRNA/mRNA regulation network was created using interaction data generated from ENCORI and revealed there are positive correlations in the infiltration of total CD4+ T cells and negative correlations in the infiltration of Th1 CD4+ T cells.
ARTICLE | doi:10.20944/preprints202305.1933.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: advanced glycation end-products (AGEs); glyceraldehyde (GA); glyceraldehyde-derived AGEs; toxic-AGEs (TAGE); p62/SQSTM1
Online: 26 May 2023 (11:53:35 CEST)
Toxic advanced glycation end-products (TAGE), formed by glyceraldehyde (GA) as an intermediate in the non-enzymatic reaction with intracellular proteins, are highly cytotoxic and have been implicated in the pathogenesis of various diseases. However, the mechanisms underlying the degradation and removal of TAGE remain largely unknown. In the present study, we identified the checkpoint kinase-1 (CHK1) mutant, d270KD, which was rapidly degraded intracellularly by GA, and showed that its degradation was mainly mediated by the ubiquitin-proteasome pathway. The high-molecular-weight complexes formed by the GA stimulation of d270KD were abundant in the RIPA-insoluble fraction, which also contained high levels of TAGE. The knockdown of p62/SQSTM1 reduced the amount of high-molecular-weight complexes in the RIPA-insoluble fraction, indicating its involvement in the formation of TAGE aggregates. The present results suggest that the ubiquitin-proteasome pathway and p62 play a role in the degradation and aggregation of intracellular TAGE formed by GA. This study provides new insights into the mechanisms underlying TAGE metabolism and may lead to the development of novel therapeutic strategies for diseases associated with TAGE accumulation.
BRIEF REPORT | doi:10.20944/preprints202305.1931.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: 16S rRNA gene; phylogenetics; amplicon metagenomics; bacterial species; gene structure and sequence
Online: 26 May 2023 (11:38:01 CEST)
Bacterial phylogenetics has largely been determined via 16S rRNA gene sequencing and phylogenetic tree reconstruction. Observed utility of this approach has driven the popularity of the 16S rRNA gene amplicon metagenomics method for profiling and identifying diverse microbes from specific habitats. This work sought to develop universal primers for amplifying the 16S rRNA gene from a consortium of disparate microbial species. Using multiple sequence alignment of the 16S rRNA gene of a variety of microbes, the resulting highly conserved region of the consensus sequence was used for design of universal polymerase chain reaction (PCR) primers for 16S rRNA gene. Application of the universal primers in simulated PCR reveals poor amplification efficiency where only 12 species out of 31 generated an amplicon. BLAST analysis of the resulting amplicons reveals a classification error of 50%. More significantly, analysis of the amplicon length indicates variable read length ranging from 81 to 122 base pair compared to the predicted read length of 100 base pairs. This suggests that the 16S rRNA gene harbours significant hitherto underappreciated sequence diversity, and may have unknown alternative splicing and recombination mechanisms. Overall, results from this study suggests that primer design for 16S rRNA amplicon metagenomics may be application and habitat specific, where it is difficult to design universal primers for all bacterial species. Conceptually, this meant that there may be sequence co-evolution in 16S rRNA gene for microbial species in the habitat where environmental and nutritional conditions impact on 16S rRNA gene structure and sequence. In essence, 16S rRNA gene may habour epigenetics signals at the gene level.
ARTICLE | doi:10.20944/preprints202305.1860.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: : Cisplatin; cilostazol; tadalafil; pentoxifylline; testicular damage
Online: 26 May 2023 (05:22:12 CEST)
Despite being extremely potent against malignancies, cisplatin (CIS) has limited practical applicability due to its adverse effects such as testicular damage. Consequently, it becomes necessary to reduce its toxicity. In this study, cilostazol, a selective phosphodiesterase-3 inhibitor that is frequently used in the treatment of intermittent claudication, was examined for its ability to abrogate CIS-induces testicular toxicity and its ameliorative effect was compared with two phosphodiesterase inhibitors, tadalafil and pentoxifylline. The study also focused on the possible mechanisms involved in the proposed protective effect. Ten groups of rats were included; Group (1): control, Groups (2-4): 5 mg/kg tadalafil or 75 mg/kg pentoxifylline or 20 mg/kg cilostazol respectively), Group (5):7 mg/kg CIS, Group (6&7): CIS + 5 mg/kg tadalafil or 75 mg/kg pentoxifylline, Group (8-10) CIS+ 5, 10 or 20 mg/kg cilostazol respectively. CIS treated rats showed a significant decrease in testicular function, serum testosterone and reduced glutathione levels, and significant elevation in malondialdehyde, total nitrite levels, tumor necrosis factor-alpha and nuclear factor-kappa β alongside caspase-3. These outcomes were confirmed by marked testicular architecture deterioration. Contrary, Cilostazol in a dose-dependent manner showed potential protection against testicular toxicity, reversion of the disrupted testicular function and improvement of the histological alterations through rebalancing of oxidative stress, inflammatory and apoptotic biomarkers. In addition, cilostazol exerted more pronounced protective effect in comparison to tadalafil and pentoxifylline. In conclusion, administrations of cilostazol might ameliorate cisplatin-induced testicular impairment through alteration of oxidative stress, inflammation, and apoptotic pathway, offering a promising treatment for cisplatin -intoxication in the testes.
ARTICLE | doi:10.20944/preprints202305.1857.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: γH2AX; Actinomycin D; Akt; DNA damage response; DNA double-strand break; DNA-PK; Etoposide; p95/NBS1
Online: 26 May 2023 (05:11:01 CEST)
DNA double-strand breakage is the most lethal damage to chromosomal DNA. It activates a series of cellular DNA damage response pathways, including DNA damage sensing, control of cell cycle arrest and apoptosis, and DNA repair. DNA damage response pathways are regulated by complex signaling machineries. Of the intracellular signaling cascades, diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DG) to generate phosphatidic acid (PA). Because both DG and PA serve as second messengers, DGK activity induces a shift of signaling pathways from DG-mediated to PA-mediated cascades, thereby implicating DGK in the regulation of widely various functions. Reportedly, one member of the DGK family, DGKζ, is intimately involved in the regulation of stress responses through p53 and NF-κB. Stresses such as ischemia and infarction cause DGKζ downregulation. Experimental DGKζ depletion renders cells and mice vulnerable to various stressors such as chemotherapeutic agents and ionizing irradiation. Nevertheless, how DGKζ is involved in DNA repair, a critical event of DNA damage response for survival remains unknown. For this study, we examined how DGKζ depletion affects DNA repair mechanisms. We demonstrated that DGKζ depletion causes attenuation of Akt activation and DNA-PK protein expression upon DNA damage, which might engender downregulated BRCA1 protein synthesis and stability. Results suggest that DGKζ depletion attenuates BRCA1-mediated DNA repair machinery, thereby conferring vulnerability to DNA damage.
REVIEW | doi:10.20944/preprints202305.1815.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: microRNA; target gene; plant growth and development; abiotic stress response
Online: 26 May 2023 (02:04:16 CEST)
MicroRNAs (MiRNAs) are a class of non-coding single-stranded RNA molecules of approximately 20-24 nucleotides in plants that play an important regulatory role in a variety of biological processes such as plant growth and development and response to various abiotic stresses. For example Drought, Salt, Cold, High temperature, Heavy metals and Nutrition. MiRNAs affect gene expression by manipulating the cleavage, translational expression or DNA methylation of target mRNAs. This review describes the current progress made on the way miRNAs are produced and regulated and the way miRNA/target gene is used in plant responses to abiotic stresses. Studying the molecular mechanism of action of miRNAs downstream target genes can optimize the genetic manipulation of crop growth and development conditions that provide a more theoretical basis for improving crop production.
REVIEW | doi:10.20944/preprints202305.1789.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: PTK6; Colorectal cancer; Tyrosine Kinase Inhibitors
Online: 25 May 2023 (09:52:24 CEST)
PTK6, a Non-Receptor–Tyrosine-Kinase, modulates the pathogenesis of breast and prostate cancers, and is recognized as a biomarker of breast cancer prognosis. There are over 30 known substrates of PTK6, including signal transducers, transcription factors and RNA binding proteins. Many of these substrates are known drivers of other cancer types such as colorectal cancer. Colon and rectal tumours also express higher levels of PTK6 than the normal intestine suggesting a potential role in tumorigenesis. However, the importance of PTK6 in colorectal cancer remains unclear. PTK6 inhibitors such as XMU-MP-2 and Tilfrinib have demonstrated potency and selectivity in breast cancer cells when used in combination with chemotherapy, indicating the potential for PTK6 targeted therapy in cancer. However, most of these inhibitors are yet to be tested in other cancer types. Here, we discuss the current understanding of the function of PTK6 in normal intestinal cells compared with colorectal cancer cells. We review existing PTK6 targeting therapeutics and explore the possibility of PTK6 inhibitory therapy for colorectal cancer.
ARTICLE | doi:10.20944/preprints202305.1780.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: genetic loci; salt tolerant indica germplasm (Akundi); single nucleotide polymorphisms (SNP); 1k-RiCA; Oryza sativa L.
Online: 25 May 2023 (08:58:09 CEST)
Achieving high-yield potential is always the ultimate objective of any breeding program. However, various abiotic stresses like salinity, drought, cold, flood, and heat hampered rice productivity tremendously. Salinity is one of the most important abiotic stresses that adversely affect rice grain yield. The present investigation was undertaken to dissect new genetic loci, which are responsible for salt tolerance at the early seedling stage in rice. A bi-parental mapping population (F2:3) was developed from the cross between BRRI dhan28/Akundi, where BRRI dhan28 (BR28) is a salt-sensitive irrigated (boro) rice mega variety and Akundi is a highly salinity tolerant Bangladeshi origin indica rice landrace that is utilized as a donor parent. We report stable QTLs for salt tolerance from a common donor (Akundi) irrespective of two different genetic backgrounds (BRRI dhan49/Akundi and BRRI dhan28/Akundi). A robust 1k-Rice Custom Amplicon (1k-RiCA) SNP marker genotyping platform was used to genotype this bi-parental population. After eliminating markers with high segregation distortion, 886 polymorphic SNPs built a genetic linkage map covering 1526.5 cM of whole rice genome with an average SNP density of 1.72 cM for the 12 genetic linkage groups. A total of 12 QTLs for nine different salt tolerance-related traits were identified using QGene and inclusive composite interval mapping of additive and dominant QTL (ICIM-ADD) under salt stress on seven different chromosomes. All of these 12 new QTLs found unique, as no other map from the previous study has reported these QTLs in the similar chromosomal location and found them different from extensively studied Saltol, SKC1, OsSalT and salT locus. Twenty-eight significant digenic/epistatic interactions identified between chromosomal regions linked to or unlinked to QTLs. Akundi acts like a new alternate donor source of salt tolerance except for other usually known donors like Nona Bokra, Pokkali, Capsule, and Hasawi used in salt tolerance genetic analysis and breeding programs worldwide, including Bangladesh. Integration of the seven novel and stable QTLs (qSES1, qSL1, qRL1, qSUR1, qSL8, qK8, qK1) reported in this investigation will expedite the cultivar development that is highly tolerant to salt stress.
ARTICLE | doi:10.20944/preprints202211.0528.v3
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: DNA strands; complementary replication; DNA alphabets; binary opposition; binary numbers; dichotomy; dichotomic tree; algebras; split-quaternions; root-complementarity
Online: 25 May 2023 (07:56:14 CEST)
This article is devoted to the results of in-depth analysis of the system of binary-oppositional structures in DNA n-plet alphabets and their algebraic-matrix representations. These results show that the molecular complementary replication of DNA strands is accompanied by the presence of an algebraic version of the principle "like begets like" in matrix representations of DNA alphabets having internal structures. This algebraic version is based on binary-oppositional structures in the genetic molecular system, which can be represented by binary numbers and corresponding matrices of DNA alphabets. The received results allow thinking that the phenomenon "like begets like" (or a complementary replication in a wide sense) is systemic in the genetic organization and is connected with algebraic features of biological organization. Correspondingly, the biological principle "like begets like" can be additionally modeled by algebraic-matrix methods and approaches. Such algebra-matrix modeling of the genetic coding system gives new ways for studying and understanding the key role of the named principle in genetic and other inherited physiological complexes. On this way, the author discovered general rules of stochastic organization of information binary sequences of genomic DNAs of eukaryotes and prokaryotes. The presented rules are connected with information dichotomies of probabilities and corresponding fractal-like trees of probabilities, which fundamentally differ from constructional dichotomies in biological bodies. The received phenomenological data and rules lead to new biological ideas.
ARTICLE | doi:10.20944/preprints202305.1610.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: tagging 20S proteasome; tagging 19S regulatory particle; proteasome subcellular localization; proteasome granules; PSMA3 (a7)
Online: 23 May 2023 (08:06:12 CEST)
Proteasomes critically regulate proteostasis via protein degradation. Proteasomes are multisubunit complexes composed of the 20S proteolytic core particle (20S CP) that, in association with one or two 19S regulatory particles (19S RPs), generate the 26S proteasome. 26S is the major proteasomal complex in the cells. Native gel protocols are used to investigate the 26S/20S ratio. However, a simple method for detecting these proteasome complexes in the cells is missing. To this end, using CRISPR technology, we YFP tagged the endogenous PSMB6 (b1) gene, a 20S CP subunit, and co-tagged endogenous PSMD6 (Rpn7), a 19S RP subunit, with mScarlet fluorescent protein. We observed colocalization of YFP and mScarlet fluorescent proteins in the cells, with higher nuclear accumulation. Nuclear proteasomal granules are formed under osmotic stress, and all were positive for YFP and mScarlet. Previously we have reported that PSMD1 knockdown, one of the 19 RP subunits, gives rise to a high level of “free” 20S CP. Intriguingly, under this condition, the 20S-YFP remained nuclear, whereas the PSMD6-mScarlet is mostly in cytoplasm, demonstrating the distinct subcellular distribution of uncapped 20S CP. Lately, we have shown that the PSMA3 (a7) C-termininus, a 20S CP subunit, binds multiple intrinsically disordered proteins (IDPs). Remarkably, truncation of the PSMA3 C-terminus is phenotypically reminiscent of PSMD1 knockdown. These data suggest the PSMA3 C-terminal region is critical for the 26S proteasome integrity.
REVIEW | doi:10.20944/preprints202305.1589.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: argon; hydrogen peroxide; hydrogen sulfide; hydroxyl radicals; molecular hydrogen; nitric oxide; peroxynitrite; protein cavities; superoxide; xenon
Online: 23 May 2023 (07:12:09 CEST)
It has been well known for a long time that inert gases, such as xenon (Xe), have significant biological effects. As these atoms are extremely unlikely to partake in direct chemical reactions with bio-molecules, such as proteins, lipids and nucleic acids, there must be some other mode of action to account for the effects reported. It has been shown that the topology of proteins allows for cavities and hydrophobic pockets, and it is through an interaction with such protein structures that inert gases are thought to have their action. Recently, it has been mooted that the relatively inert gas molecular hydrogen (H2), also may have its effects through such a mechanism, and so influencing protein structures and actions. H2 is thought to also act through interaction with redox active compounds, particularly the hydroxyl radical (·OH) and peroxynitrite (ONOO-), but not nitric oxide (NO·), superoxide anions (O2·-) or hydrogen peroxide (H2O2). However, instead of having a direct interaction with H2, is there any evidence that these redox compounds can also interact with Xe pockets and cavities in proteins, so either having an independent effect on proteins or interfering with the action of inert gases. This suggestion with be explored here.
ARTICLE | doi:10.20944/preprints202305.1587.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: cis-regulatory element; fruit ripening; malate; NADPH; NADP dehydrogenases; nitric oxide; pepper
Online: 23 May 2023 (05:43:05 CEST)
NADPH is an indispensable cofactor in a wide range of physiological processes which is generated by a family of NADPH-dehydrogenases, where the NADP-dependent malic enzyme (NADP-ME) is one member of these enzymes. Pepper (Capsicum annuum L.) fruit is a horticultural product worldwide consumed which has great nutritional and economic relevance. Besides the phenotypical changes that undergo pepper fruit during ripening, there are many associated modifications at transcriptomic, proteome ic, biochemical, and metabolic levels. Nitric oxide (NO) is a recognized signal molecule that can exert regulatory functions in diverse plant processes. To our knowledge, there is very scarce information about the number of genes encoding for NADP-ME in pepper plants and their expression during the ripening of sweet pepper fruit. Based on a data-mining approach on the pepper plant genome and fruit transcriptome (RNA-seq), five NADP-ME genes were identified, and four of them, namely CaNADP-ME2 to CaNADP-ME5, were expressed in fruit. The time-course expression analysis of these genes during different fruit ripening stages including green immature (G), breaking point (BP), and red ripe (R) showed that they were differentially modulated. Thus, while CaNADP-ME3 and CaNADP-ME5 were upregulated, CaNADP-ME2 and CaNADP-ME4 were downregulated. Exogenous NO treatment of fruit triggered the downregulation of CaNADP-ME4. Furthermore, the analysis of the cis-regulatory elements showed that CaNADP-ME2 and CaNADP-ME5 were positively regulated by the light-responsive element Box4 whereas CaNADP-ME4 was by ABRE (ACGT-containing abscisic acid response element), which is involved in the abscisic acid (ABA) responsiveness. To get deeper knowledge on this enzyme system from fruits, we obtained the 50-75% ammonium-sulfate-enriched protein fraction containing CaNADP-ME enzyme activity, and this was assayed by non-denaturing polyacrylamide gel electrophoresis (PAGE). The results allowed identifying four isozymes designated CaNADP-ME I to CaNADP-ME IV. Taken together, the data provide new pieces of information on the CaNADP-ME system with the identification of five CaNADP-ME genes and how the four genes expressed in pepper fruits are modulated during ripening and by exogenous NO gas treatment.
ARTICLE | doi:10.20944/preprints202305.1512.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: cannabidiol; delta-9-hydrocannabinol; CBD; THC; THP-1 macrophages; Cannabis sativa; inflammation; lipopolysaccharide
Online: 22 May 2023 (11:00:01 CEST)
Inflammation is the response of the innate immune system to any type of injury. Although acute inflammation is critical for survival, dysregulation of innate immune response leads to chronic in-flammation. Many synthetic anti-inflammatory drugs have side effects, and thus, natural an-ti-inflammatory compounds are still needed. Cannabis sativa L. may provide a good source of in-flammation-reducing molecules. Here, we tested the anti-inflammatory properties of cannabis ex-tracts and pure cannabinoids in lipopolysaccharide (LPS)-induced inflammation in human THP-1 macrophages. We found that pre-treatment with cannabidiol (CBD), delta-9-tetrahydrocannabinol (THC), or extracts containing high levels of CBD or THC reduce the level of induction of various cytokines. The CBD was more efficient than THC, and the extracts were more efficient than pure cannabinoids. Finally, IL-6, IL-10 and monocyte chemoattractant protein-1 (MCP-1) were most sensitive to pre-treatments with CBD and THC, while IL-1β, IL-8 and TNF-α were less responsive. Thus, our work demonstrates the potential of use of cannabinoids or/and cannabis extracts for the reduction of inflammation and establishes IL-6 and MCP-1 as the sensitive markers for the analysis of the effect of cannabinoids on inflammation in macrophages.
REVIEW | doi:10.20944/preprints202305.1496.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Quercetin; xanthine oxidase; myeloperoxidase; nicotinamide adenine dinucleotide phosphate oxidase; lipoxygenase; monoamine oxidase; docking
Online: 22 May 2023 (10:12:36 CEST)
Oxidative stress is defined as an imbalance between the production of free radicals and reactive oxygen species (ROS) and the ability of the body to neutralize them by antioxidant defense systems. Cells produce ROS as a control of physiological processes, but increasing ROS becomes pathological leading to non-specific and irreversible damage to biological molecules, such as DNA, lipid, and protein. Endogenous ROS are mainly produced by mitochondria during both physiological and pathological conditions, and enzymes, such as nicotinamide adenine dinucleotide phosphate oxidase (NOX), xanthine oxidase (XO), lipoxygenase (LOX), myeloperoxidase (MPO) and monoamine oxidase (MAO). To neutralize ROS, the body employs enzymatic and non-enzymatic defense systems. The dietary intake of bioactive phenols, such as quercetin (Que), is a non-enzymatic system that can quench ROS and protect from pro-oxidative damage. In this review, we evaluate the ability of Que to target endogenous oxidant enzymes involved in ROS production and explore the mechanisms of action underlying its antioxidant properties. Que not only acts as a free radical scavenger by donating electrons through the negative charges in its phenolic and ketone groups, but it can effectively inhibit the activity of several endogenous oxidative enzymes, binding them with high affinity and specificity. Among all targets, Que showed the best results in molecular docking simulations with XO, followed by MAO-A, 5-LOX, NOX, and MPO. Taken together, these findings highlight the potential of Que as a natural antioxidant therapy for oxidative stress-related diseases.
ARTICLE | doi:10.20944/preprints202305.1482.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: genetic manipulation; pleiotropic effects; systems biology
Online: 22 May 2023 (09:03:52 CEST)
In T. gondii, as well as in other model organisms, gene knock-out using CRISPR-Cas9 is a suitable tool to identify the role of specific genes. The general consensus implies that only the gene of interest is affected by the knock-out. Is this really the case? In a previous study, we have generated knock-out (KO) clones of TgRH88_077450 (SRS29B; SAG1) which differed in the numbers of integrated dihydrofolate-reductase-thymidylate-synthase (MDHFR-TS) drug-selectable marker. Clones 18 and 33 had a single insertion of MDHFR-TS within SRS29B. Clone 6 was disrupted by the insertion of a short unrelated DNA-sequence, but the marker was integrated elsewhere. In clone 30, the marker was inserted into SRS29B and several other MDHFR-TS copies were found in the genome. KO and wild-type (WT) tachyzoites had similar shape, dimensions and vitality. This prompted us to investigate the impact of the genetic engineering as such on the overall proteome patterns of the four clones as compared to the respective WT. Comparative shotgun proteomics of the five strains was performed. Overall, 3236 proteins were identified. Principal component analysis of the proteomes revealed five distinct clusters corresponding to the five strains by both iTop3 and iLFQ algorithms. Detailed analysis of the differentially expressed proteins revealed that the target of the KO, srs29B, was lacking in all KO clones. Besides this protein, twenty other proteins were differentially expressed between KO clones and WT or between different KO clones. The protein exhibiting the highest variation between the five strains was srs36D encoded by TgRH_016110. The deregulated expression of SRS36D was further validated by quantitative PCR. Moreover, the transcript levels of three other selected SRS genes, namely SRS36B, SRS46, and SRS57 exhibited significant differences between individual strains. These results indicate that knocking out a given gene may affect the expression of other genes. Therefore, care must be taken when specific phenotypes are regarded as a direct consequence of the KO of a given gene.
REVIEW | doi:10.20944/preprints202305.1461.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Microalgae; Diazotroph; Nitrogen fixation; Consortia; Mutualism; Biotechnology
Online: 22 May 2023 (04:53:55 CEST)
Microalgae are used in various biotechnological processes, such as biofuel production due to their high biomass yields, agriculture as biofertilizers, production of high-value-added products, de-contamination of wastewater, or as biological models for carbon sequestration. The number of these biotechnological applications is increasing, and as such, any advances that contribute to reducing costs and increasing economic profitability can have a significant impact. Nitrogen fixing organisms, often called diazotroph, also have great biotechnological potential, mainly in agri-culture as an alternative to chemical fertilizers. Microbial consortia typically perform more com-plex tasks than monocultures and can execute functions that are challenging or even impossible for individual strains or species. Interestingly, microalgae and diazotrophic organisms are capable to embrace different types of symbiotic associations. Certain corals and lichens exhibit this sym-biotic relationship in nature, which enhances their fitness. However, this relationship can also be artificially created in laboratory conditions with the objective of enhancing some of the biotech-nological processes that each organism carries out independently. As a result, the utilization of microalgae and diazotrophic organisms in consortia is garnering significant interest as a potential alternative for reducing production costs and increasing yields of microalgae biomass, as well as for producing derived products and serving biotechnological purposes. This review makes an effort to examine the associations of microalgae and diazotrophic organisms, with the aim of highlighting the potential of these associations in improving various biotechnological processes.
ARTICLE | doi:10.20944/preprints202305.1403.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Alzheimer’s Disease; Tauopathy; Cell penetrating peptide; Polyarginine; TAT; Liposomes; Nanoparticles; Tau pathology; Tau aggregation inhibitor; Endocytosis
Online: 19 May 2023 (08:06:10 CEST)
Given the pathological role of hyperphosphorylated Tau aggregation in Alzheimer’s disease (AD) our laboratory previously developed the novel Tau aggregation inhibitor peptide, RI-AG03. As Tau aggregates accumulate intracellularly, it is essential that Tau-targeting peptides efficiently traverse the cell membrane. In addition, these peptides need to avoid sequestration into cell organelles, particularly those involved in degradation, to ensure interaction with Tau in the cytoplasm. Here, we examine the cellular uptake and intracellular trafficking of RI-AG03 when the peptide is unconjugated or linked to nanoliposome carrier particles. The impact of adding the cell penetrating peptide (CPP) sequences, polyarginine (polyR) and transactivator of transcription (TAT), to RI-AG03 was also characterised. Our data show that the conjugation of CPP-containing RI-AG03 to liposomes dramatically increases cellular liposomes uptake. The majority of this uptake occurs via direct cell penetration. However, we find that macropinocytosis is also an important mechanism for unconjugated and RI-AG03-polyR-conjugated, but not RI-AG03-TAT-conjugated, liposome uptake. In agreement with this macropinocytosis-mediated internalisation, liposome lipids localise to lysosomes and macropinosomes following cellular uptake. However, while unconjugated RI-AG03 peptides also localise to lysosomes, liposome conjugation prevents this localisation, with the peptide detaching from the liposomes at the cell surface and evading organelle entrapment. Overall, this study demonstrates that CPP sequences and nanoliposomes carriers enhance the intracellular delivery of RI-AG03, furthering the possibility of the peptide’s use in targeting Tau pathology in AD.
ARTICLE | doi:10.20944/preprints202305.1339.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Multiple myeloma; monoclonal gammopathy of undetermined significance; serum diagnostic metabolites; Nuclear Magnetic Resonance
Online: 18 May 2023 (11:02:34 CEST)
Multiple myeloma (MM) is an incurable hematological cancer. It is preceded by monoclonal gammopathy of uncertain significance (MGUS), an asymptomatic phase. It has been demonstrated that early detection increases the 5-year survival rate. However, blood-based biomarkers that enable early disease detection are lacking. Metabolomic and lipoprotein subfraction variable profiling is gaining traction to expand our understanding of disease states and, more specifically, for identifying diagnostic markers in patients with hematological cancers. This study aims to enhance our understanding of multiple myeloma (MM) and identify candidate metabolites, allowing for more effective preventative treatment. Serum was collected from 25 healthy controls, 20 patients with MGUS, and 30 patients with MM. 1H-NMR (nuclear magnetic resonance) spectroscopy was utilized to evaluate serum samples. The metabolite concentrations were examined using multivariate, univariate, and pathway analysis. Metabolic profiles of the MGUS patients revealed lower levels of alanine (F.C. = 0.8, p = 0.002), lysine (FC = 0.8, p < 0.001), leucine (FC=0.7, p < 0.001) but higher levels of formic acid (FC=1.6, p ≤ 0.001) when compared to controls. However, metabolic profiling of MM patients compared to controls exhibited decreased levels of total Apolipoprotein-A1 (FC =0.6, p<0.001), HDL-4 Apolipoprotein-A1 (FC = 0.5, p ≤ 0.001), HDL-4 Apolipoprotein-A2 (FC = 0.6, p < 0.001), HDL Free Cholesterol (FC = 0.7, p < 0.001), HDL-3 Cholesterol (FC = 0.5, p ≤ 0.001) and HDL-4 Cholesterol (FC = 0.5, p ≤ 0.001). Lastly, metabolic comparison between MGUS to MM patients primarily indicated alterations in lipoproteins levels: Total Cholesterol (FC = 0.6, p ≤ 0.001), HDL Cholesterol (FC = 0.7, p ≤ 0.001), HDL Free Cholesterol (FC = 0.4, p ≤ 0.001), Total Apolipoprotein-A1 (FC = 0.7, p ≤ 0.001), HDL Apolipoprotein-A1 (FC = 0.7, p ≤ 0.001), HDL-4 Apolipoprotein-A1 (FC = 0.6, p ≤ 0.001) and HDL-4 Phospholipids (FC = 0.6, p ≤ 0.001). This study provides novel insights into the serum metabolic and lipoprotein subfraction changes in patients as they progress from a healthy state to MGUS to MM, which may allow for earlier clinical detection and treatment.
ARTICLE | doi:10.20944/preprints202305.1300.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Apoptosis; PD-L1; catalytic topo I inhibitor; cyclin D1 overexpression; ATR; p53
Online: 18 May 2023 (08:31:34 CEST)
Apoptosis under severe hypoxia is induced through p53 phosphorylation and HIF-1?-dependent p53 accumulation via ATR activation by DNA damage response (DDR) activation through replication stress. We previously demonstrated that the topoisomerase I catalytic inhibitor, 3EZ, 20Ac-ingenol, specifically induced apoptosis in Jeko-1 and Panc-1 cells, both of which are cell lines that show cyclin D1 overexpression. After progression to the S phase facilitated by nuclear cyclin D1, in the presence of 3EZ, 20Ac-ingenol, an intra S phase checkpoint was induced in ATR activation as part of replication stress-induced DDR. In this study, we examined whether 3EE, 20Ac-ingenol induces a higher degree of p53 phosphorylation and additional HIF-1? and p53 accumulation in response to replication stress-induced DDR activation under the hypoxic condition than under the normoxic condition by controlling ATR activation. 3EE, 20Ac-ingenol induced p53 activation and HIF-1?-dependent p53 accumulation through cooperative ATR activation via induced DDR with the hypoxia in Panc-1 cells. The Jeko-1 cells showed slight HIF-1? accumulation under hypoxia, but this was not decreased by 3EE, 20Ac-ingenol, so that the cells remained resistant to hypoxia. 3EE, 20Ac-ingenol induces an intricate interplay between p53 and HIF-1? accumulation via ATR activations that results in high p53 accumulation, which advanced transient expression and early disappearance of HIF-1?. The strong p53 accumulation and consequent PTEN activation also decreased HIF-1? accumulation and PD-L1 expression, which resulted in intense apoptosis.
REVIEW | doi:10.20944/preprints202305.1263.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: liver disease; inflammation; steatosis; ALD; NAFLD; ASH; NASH; angiogenesis; hepatocellular carcinoma; natural compounds.
Online: 18 May 2023 (03:45:43 CEST)
Alcoholic Liver Disease (ALD) and Non-Alcoholic Fatty Liver Disease (NAFLD) are the most common causes of chronic liver disease and are increasingly emerging as a global health problem. Such disorders can lead to liver damage, resulting in the release of pro-inflammatory cytokines and the activation of infiltrating immune cells. These are some of the common features of ALD progression in ASH (alcoholic steatohepatitis) and NAFLD to NASH (non-alcoholic steatohepa-titis). Hepatic steatosis and subsequent fibrosis, whose continuous progression is accompanied by angiogenesis, lead to hypoxia, inducing the activation of vascular factors, which in turn triggers pathological angiogenesis and subsequent fibrosis, resulting in a vicious cycle. This condition further exacerbates liver injury and may contribute to the development of comorbidities, such as metabolic syndrome as well as hepatocellular carcinoma. Increasing evidence suggests that antiangiogenic therapy may have beneficial effects on these hepatic disorders and their exacerbation. Therefore, there is a great interest to deepen the knowledge of the molecular mechanisms of natural antiangiogenic products that could both prevent and control liver diseases. In this review, we focus on the role of major natural antian-giogenic compounds against steatohepatitis and determine their potential therapeutic benefits in the treatment of liver inflammation.
REVIEW | doi:10.20944/preprints202305.1259.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Chlamydomonas; Microalgae; Molybdenum; Homeostasis; Moco
Online: 18 May 2023 (02:13:04 CEST)
Molybdenum (Mo) is vital for the activity of a small but essential group of enzymes called mo-lybdoenzymes. So far, specifically five molybdoenzymes have been discovered in eukaryotes: nitrate reductase, sulfite oxidase, xanthine dehydrogenase, aldehyde oxidase, and mARC. In order to become biologically active, Mo must be chelated to a pterin, forming the so-called Mo cofactor (Moco). Deficiency or mutation in any of the genes involved in Moco biosynthesis results in the simultaneous loss of activity of all molybdoenzymes, fully or partially preventing the normal development of the affected organism. To prevent this, the different mechanisms in-volved in Mo homeostasis must be finely regulated. Chlamydomonas reinhardtii is a unicellular, photosynthetic, eukaryotic microalga that has produced fundamental advances in key steps of Mo homeostasis over the last 30 years, which have been extrapolated to higher organisms, both plants and animals. These advances include the identification of the first two molybdate transporters in eukaryotes (MOT1 and MOT2), the characterization of key genes in Moco biosynthesis, the identification of the first enzyme that protects and transfers Moco (MCP1), the first characteriza-tion of mARC in plants, and the discovery of the crucial role of the nitrate reductase-mARC complex in plant nitric oxide production. This review aims to summarize all these advances made using C. reinhardtii as a model organism in Mo homeostasis and suggest how this microalga can continue to contribute to progress in this field.
ARTICLE | doi:10.20944/preprints202305.1237.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: aniridia; biomarker; COMET; cornea; LSCD; neovascularization; oral mucosa; PITX2; ocular surface
Online: 17 May 2023 (10:45:28 CEST)
Total bilateral Limbal Stem Cells Deficiency is a pathologic condition of the ocular surface due to the loss of corneal stem cells. Cultivated Oral Mucosa Epithelial Transplantation (COMET) is the only autologous successful treatment for this pathology in clinical application, although non-physiological peripheric corneal vascularization often occurs. Properly characterizing the regenerated ocular surface is needed for a reliable follow-up. So far, the univocal identification of transplanted oral mucosa had been challenging. Previously proposed markers were shown co-expressed by the different ocular surface epithelia in a homeostatic or perturbated environment. In this study, we compared the transcriptome profile of human oral mucosa, limbal and conjunctival cells, identifying PITX2 as a new marker that univocally distinguishes the transplanted oral tissue from the other epithelia. We validated PITX2 at RNA and protein levels to investigate 10-year follow-up cor-neal samples derived from a COMET-treated aniridic patient. Moreover, we found novel angiogenesis-related factors differentially expressed in the three epithelia and instrumental in explaining the neovascularization in COMET-treated patients. These results will support the follow-up analysis of patients transplanted with oral mucosa and provide new tools to understand the regeneration mechanism of the transplanted cornea.
REVIEW | doi:10.20944/preprints202305.1221.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: cGMP; cGKI; IP3R-I; IP3R-II; IP3R-III; IRAG; IRAG1; IRAG2, Jaw1; LRMP; MRVI1; PKGI
Online: 17 May 2023 (10:08:21 CEST)
The inositol triphosphate associated proteins IRAG1 and IRAG2 are cGMP kinase substrate proteins, which regulate intracellular Ca2+. Previously, IRAG1 was discovered as a 125 kDa membrane protein at the endoplasmic reticulum, that is associated with the intracellular Ca2+ channel IP3R-I and the PKGIβ and inhibits IP3R-I upon PKGIβ-mediated phosphorylation. IRAG2 is a 75 kDa membrane protein homologue of IRAG1 and was recently also determined as a PKGI substrate protein. Several (patho-)physiological functions of IRAG1 and IRAG2 were meanwhile and recently elucidated in a variety of human and murine tissues, e.g. of IRAG1 in various smooth muscles, heart, platelets and other blood cells, of IRAG2 in pancreas, heart, platelets and taste cells. Hence, lack of IRAG1 or IRAG2 leads to diverse phenotypes in these organs, e.g. smooth muscle and platelet disorders or secretory deficiency, respectively. This review aims to highlight the recent research regarding these both regulatory proteins to envision its molecular and (patho-)physiological tasks and to unravel its functional interplay as possible (patho-)physiological counterparts.
ARTICLE | doi:10.20944/preprints202305.1194.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Breast cancer; obesity; metabolic syndrome; rat model; DMBA; insulin signaling; PI3/Akt
Online: 17 May 2023 (05:25:25 CEST)
It was found that patients with comorbidities of obesity and diabetes have a high risk of breast cancer occurrence and face worse breast cancer outcomes. Though several reports showed the reinforced link between obesity, diabetes, and prediabetes with breast cancer, the underlying molecular mechanism is still unknown. The present study aimed to investigate the underlying molecular link between increased risks of breast cancer due to coincident diabetes or obesity using a spontaneous obese rat model with impaired glucose tolerance (WNIN/GR-Ob rat). A single dose of solubilized DMBA suspension (40 mg/kg body weight) was orally administered to the animals at the age of 60 days to induce breast tumors. The tumor incidence, latency period, tumor frequency, and tumor volume were measured. Histology, immunohistochemistry, and immunoblotting were performed to evaluate the tumor morphology and expression levels of signal molecules. It was observed that the onset of breast tumor and latency period per tumor development were early in GR-Ob rats compared to respective lean rats. It was found that 62% of obese rats were bearing tumors, and in comparison, only 21% of the lean animals developed breast tumors. Overexpression of ER, PR, Ki67, and p53 markers was observed in tumor tissues of obese rats in comparison with lean rats. The levels of the hallmarks of cell proliferation and angiogenesis involved in IGF-1/PI3K/Akt/GSK3β/β-catenin signaling pathway molecules were upregulated in obese rat breast tumors compared to lean rats. Furthermore, obesity with prediabetes is associated with changes in IGF-1 signaling and acts on PI3K/Akt/GSK3β/β-catenin signaling, which results in quick cell proliferation and development of breast tumors in obese rats than the lean rats. These results indicate that the onset of the tumor and its development was faster in a spontaneous obese rat model with impaired glucose tolerance than their lean counterparts, with a higher percentage of tumor incidence.
REVIEW | doi:10.20944/preprints202305.1163.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: connexin 43; connexin 30; connexin 26; gap junctions; transport
Online: 16 May 2023 (11:41:45 CEST)
The connexin gene family is the most prevalent gene that contributes to hearing loss. Connexins 26 and 30, encoded by GJB2 and GJB6 respectively, are the most abundant expressed connexins in the inner ear. Connexin 43 which is encoded by GJA1 appears to be widely expressed in various organs, including the heart, skin, brain, and inner ear. The mutations that arise in GJB2, GJB6 and GJA1 can all result in comprehensive or non-comprehensive genetic deafness in newborns. As it is predicted that connexins include at least 20 isoforms in humans, the biosynthesis, structural composition, and degradation of connexins must be precisely regulated so that the gap junctions can operate properly. Certain mutations result in connexins possessing a faulty subcellular localization, failing to transport to the cell membrane and preventing gap junction formation, ultimately leading to connexin dysfunction and hearing loss. In this review, we provide a discussion of the transport models for connexin 43, connexins 30 and 26, mutations affecting trafficking pathways of connexin 26, the existing controversies in trafficking pathways of connexins, and the molecules involved in connexin trafficking and their functions. This review can contribute to a new way of understanding the etiological principles of connexin mutations and finding therapeutic strategies for hereditary deafness.
ARTICLE | doi:10.20944/preprints202305.1160.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Laterality; Ion Channel; Breast Cancer; Proliferation; Stemness
Online: 16 May 2023 (11:01:00 CEST)
Breast cancer is a complex and heterogeneous disease that displays diverse molecular subtypes and clinical outcomes. Although it is known that the location of tumors can affect their biological behavior, the underlying mechanisms are not fully understood. In our previous study, we found a differential methylation profile and membrane potential between left (L) and right (R)-sided breast tumors. In this current study, we aimed to identify the ion channels responsible for this phenomenon and determine any associated phenotypic features. To achieve this, experiments were conducted in mammary tumors in mice, human patient samples, and with data from public datasets. The results revealed that L-sided tumors have a more depolarized state than R-ones. We identified a 6-ion channel-gene signature (CACNA1C, CACNA2D2, CACNB2, KCNJ11, SCN3A, and SCN3B) associated with side: L-tumors exhibit lower expression levels than R-ones. Additionally, in silico analyses show that the signature correlates inversely with DNA methylation writers and with key biological processes involved in cancer progression, such as proliferation and stemness. The signature also correlates inversely with patients’ survival rates. In an in vivo mouse model, we confirmed that KI67 and CD44 markers were increased in L-sided tumors and similar tendency for KI67 was found in patient L-tumors. Overall, this study provides new insights into the potential impact of anatomical location on breast cancer biology and highlights the need for further investigation into possible differential treatment options.
ARTICLE | doi:10.20944/preprints202305.1046.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: esophageal squamous cell carcinoma; gene; mRNA; piRNA; diagnosis
Online: 15 May 2023 (12:43:54 CEST)
Recently, a database of human piRNAs has been created, which allows studying the binding of many piRNAs to mRNAs of genes involved in many diseases, including cancer. In the present work, we investigated what piRNAs can interact with candidate esophageal squamous cell carcinoma (ESCC) genes. The binding of 480 thousand piRNAs with mRNAs of 66 candidate ESCC genes was studied. Bioinformatic studies found that piRNAs bind only to the mRNAs of nine candidate genes: AURKA, BMP7, GCOM1, ERCC1, MTHFR, SASH1, SIX4, SULT1A1, and TP53. It has been shown that piRNAs can bind to mRNA by overlapping nucleotide sequences in limited 3'UTR and 5'UTR regions called clusters of binding sites (BSs). The existence of clusters of piRNA BSs significantly reduces the proportion of nucleotide sequences of these sites in the mRNA of target genes. Competition between piRNAs occurs for binding to the mRNA of target genes. Individual piRNAs and groups of piRNAs that have separate BSs and clusters of BSs in the mRNAs of two or more candidate genes have been identified in the mRNAs of these genes. This organization of piRNAs BSs indicates the interdependence of the expression of candidate genes through piRNAs. Significant differences in the ability of genes to interact with piRNAs avoid the side effects of piRNAs on genes with the lack of binding of such piRNAs. Individual piRNAs and sets of piRNAs are proposed and recommended for the diagnosis and therapy of ESCC.
ARTICLE | doi:10.20944/preprints202305.1041.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Microbial physiology; Quorum Sensing; Quorum Quenching; Pseudomonas aeruginosa
Online: 15 May 2023 (12:13:55 CEST)
After a time away from the classrooms and laboratories due to the global pandemic, the return to the teaching activities during the semester represented a challenge to both teachers and students. Our particular situation in a Microbial Physiology course was the necessity of imparting in a shorter time, laboratory practices that usually take longer. This article describes a two-week long laboratory exercise that covers several concepts in an interrelated way: conjugation as a gene transfer mechanism, regulation of microbial physiology, production of secondary metabolites, degradation of macromolecules and biofilm formation. Utilizing a Quorum Quenching (QQ) strategy, the Quorum Sensing (QS) system of Pseudomonas aeruginosa is first attenuated. Then, phenotypes regulated by QS are evidenced. QS is a regulatory mechanism of the microbial physiology that relays on signal molecules. QS is related in P. aeruginosa to several virulence factors, some of which are exploited in the laboratory practices presented in this work. QQ is phenomenon by which QS is interrupted or attenuated. We utilized a QQ approach based on the enzymatic degradation of the P. aeruginosa QS signals in order to put in evidence QS-regulated traits that are relevant for our Microbial Physiology course.
REVIEW | doi:10.20944/preprints202305.1024.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: coenzyme Q10, oxidative stress, primary deficiency, blood brain barrier, mitochondrial, supplementation
Online: 15 May 2023 (10:36:16 CEST)
Abstract Coenzyme Q10 (CoQ10) has a number of vital functions in all cells, both mitochondrial and extra-mitochondrial. In addition to its key role in mitochondrial oxidative phosphorylation, CoQ10 serves as a lipid soluble antioxidant, plays an important role in fatty acid beta-oxidation and pyrimidine and lysosomal metabolism, as well as directly mediating the expression of a number of genes, including those involved in inflammation. Because of the multiplicity of roles in cell function, it is not surprising that deficiency of CoQ10 has been implicated in the pathogenesis of a wide range of disorders. CoQ10 deficiency is broadly divided into primary and secondary types. Primary CoQ10 deficiency results from mutations in genes involved in the CoQ10 biosynthetic pathway. In man, at least 10 genes are required for the biosynthesis of functional CoQ10, a mutation in any one of which can result in a deficit in CoQ10 status. Patients may respond well to oral CoQ10 supplementation, although the condition must be recognised sufficiently early, before irreversible tissue damage has occurred. In this article, we have reviewed clinical studies (up to March 2023) relating to the identification of these deficiencies, and the therapeutic outcomes of CoQ10 supplementation.
ARTICLE | doi:10.20944/preprints202305.1020.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Costaria costata; fucoidan; idiopathic pulmonary fibrosis
Online: 15 May 2023 (10:27:55 CEST)
Pulmonary fibrosis is a chronic, progressive and fatal disease of the interstitial lung， there still lack of efficient therapy to reverse the prognosis of patients currently. In this study, a fucoidan from Costaria costata was isolated and its anti-idiopathic fibrosis activity was investigated both in vitro and in vivo. The chemical composition analysis results show that Costaria costata polysaccharide (CCP) is consisting of galactose and fucose as the main monosaccharides with a sulfate group content of 18.54%. The results found that CCP could resist TGF-β1-induced epithelial-mesenchymal transition (EMT) in A549 cells by inhibiting the TGF-β/Smad and PI3K/AKT/mTOR signaling pathways. In vivo data found that CCP treatment alleviated bleomycin (BLM)-stimulated fibrosis and inflammation in mice lung tissue. This study suggests that CCP could protect the lung from fibrosis by relieving the EMT process and inflammation in lung cells.
ARTICLE | doi:10.20944/preprints202305.0978.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: malignant mesothelioma; metabolism; mitochondria; long-chain specific acyl-CoA dehydrogenase; fatty acid β-oxidation, biomarker
Online: 15 May 2023 (05:27:55 CEST)
Cross-species investigations on cancer invasiveness are a new approach that identified new biomarkers potentially useful for improving tumor diagnosis and prognosis in clinical medicine and veterinary science. In this study, we combined proteomic analysis of four experimental rat malignant mesothelioma (MM) tumors with analysis of ten patient-derived cell lines to identify common features associated to mitochondrial proteome rewiring. The comparison of significant abundance changes between invasive and non-invasive rat tumors rat tumors gave a list of 433 proteins, including twenty-six proteins reported to be exclusively located in mitochondria. Next, we analyzed the differential expression of genes encoding the mitochondrial proteins of interest in five primary epithelioid and five primary sarcomatoid human MM cell lines, and the most impressive increase was observed in the expression of the long-chain acyl coenzyme A dehydrogenase (ACADL). To evaluate the role of this enzyme in the migration/invasiveness, two epithelioid and two sarcomatoid human MM cell lines derived from patients with the highest and lowest overall survival were studied. Interestingly, sarcomatoid vs epithelioid cell lines were characterized by higher migration and fatty oxidation rates, in agreement with ACADL findings. These results suggest that evaluating mitochondrial proteins in MM specimens might identify tumors with higher invasiveness.
ARTICLE | doi:10.20944/preprints202305.0844.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Peptidomimetic; VEGFR2; Angiogenesis; Tumor suppression; PI3K/Akt/mTOR signaling pathway; PLCγ/ERK signaling pathway
Online: 11 May 2023 (10:57:38 CEST)
Vascular endothelial growth factor receptor 2 (VEGFR2) mediates VEGFA signaling mainly through the PI3K/AKT/mTOR and PLCγ/ERK1/2 pathways. Here we unveil a peptidomimetic (VGB3) based on the interaction between VEGFB and VEGFR1 that unexpectedly binds and neutralizes VEGFR2. Investigation of the cyclic and linear structures of VGB3 using receptor binding and cell proliferation assays, molecular docking, and evaluation of antiangiogenic and antitumor activities in the 4T1 mouse mammary tumor model showed that loop formation is essential for peptide functionality. VGB3 inhibited proliferation and tubulogenesis of human umbilical vein endothelial cells (HUVECs), accounting for the abrogation of VEGFR2, p-VEGFR2 and, subsequently, PI3K/AKT/mTOR and PLCγ/ERK1/2 pathways. In 4T1 cells, VGB3 inhibited cell proliferation, VEGFR2 expression and phosphorylation, PI3K/AKT/mTOR pathway, FAK/Paxillin, and epithelial-to-mesenchymal transition cascade. The apoptotic effects of VGB3 on HUVE and 4T1 cells were inferred from annexin-PI and TUNEL staining and activation of P53, caspase-3, caspase-7, and PARP1, which mechanistically occurred through the intrinsic pathway mediated by Bcl2 family members, Cytochrome c, Apaf-1 and caspase-9, and extrinsic pathway via death receptors and caspase-8. These data indicate that binding regions shared by VEGF family members may be important in developing novel pan-VEGFR inhibitors that are highly relevant in the pathogenesis of angiogenesis-related diseases.
TECHNICAL NOTE | doi:10.20944/preprints202305.0835.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: degraded metagenome; shotgun metagenomics; stomach acid; microbial identification; percent identity
Online: 11 May 2023 (09:25:18 CEST)
Metagenomics have opened our eyes to the otherwise enigmatic microbial consortia that relies on different human body niches that impact on disease pathogenesis. This work originally aims to re-analyse a public shotgun metagenomics dataset to glean insights on the microbial species that may partake in stomach cancer pathogenesis. However, a random selection of sequenced reads reveals poor percent identities (79 to 94%) of the microbial identification obtained in a BLAST search. This surprising result suggests possible stomach acid induced degradation or modification of the sequenced read that reduced the effectiveness of the metagenomics approach in microbial identification. Further analysis of the dataset highlights that poor percent identities did not arise due to highly fragmented nature of the genetic material where there is a good abundance of sequenced reads in the 100 to 1300 base pair category. More intriguingly, attempts to obtain a correlation between percent identity and read length did not reveal a correlation which meant that stomach acid did not modify all types of nucleotides. More likely, stomach acid only modified low abundance nucleotide in this case, which point to the probability of identifying a microbe in the modified gene fragment in totally unpredictable ways. Overall, data reported in this work suggests caution in the interpretation of results of shotgun metagenomics studies of stomach cancer microbiota where stomach acid likely degraded the genetic material of microbes that may result in mis-identification.
REVIEW | doi:10.20944/preprints202305.0756.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: synucleins; cancer; aggregation; pathways; biomarkers
Online: 10 May 2023 (13:58:12 CEST)
Synucleins are a family of small, soluble proteins mainly expressed in neural tissue and in certain tumors. Since their discovery, tens of thousands of scientific reports have been published about this family of proteins as they are associated to severe human diseases. Although the physiological function of these proteins still elusive, their relation with neurodegeneration and cancer was clearly described over the years. In this review, we summarize data connecting synucleins and cancer, going from the structural description of these molecules, to their involvement in tumor-related processes, and discuss the putative use of this proteins as cancer molecular biomarkers.
REVIEW | doi:10.20944/preprints202305.0720.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Prostate cancer; androgen receptor; AR signaling pathway; disease progression; therapeutic re-sistance; personalized treatment; androgen deprivation therapy; AR-targeted therapies
Online: 10 May 2023 (09:09:13 CEST)
Prostate cancer (PCa) is a significant cause of cancer-related deaths globally, with an increasing incidence over the years. Our review article aims to unlock the secrets of androgen receptors in prostate cancer susceptibility, progression, and treatment by analyzing recent literature. Androgen receptor (AR) plays a crucial role in male development and maintains masculine characteristics. However, in prostate cancer, AR signaling pathway aberrations can lead to disease progression and treatment resistance. Understanding AR regulation and function in healthy and diseased states is essential for developing effective treatment strategies to combat this disease and improve patient outcomes. Our findings have significant implications for developing new treatments and identifying biomarkers for early detection and personalized treatment targeting the AR signalling pathway.
REVIEW | doi:10.20944/preprints202305.0618.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: phycobilisome; phycobilin; phycobiliprotein; assembly; biosynthesis; photosynthesis
Online: 9 May 2023 (08:56:09 CEST)
The phycobilisome (PBS) is the major light-harvesting apparatus in cyanobacteria and red algae, a large multi-subunit protein complex of several megadaltons that is found on the stromal side of thylakoid membranes in orderly arrays. Chromophore lyases catalyse the thioether bond between apoproteins and phycobilins of PBSs. Depending on the species, composition, spatial assembly and, especially, the functional tuning of different phycobiliproteins mediated by linker proteins, PBSs can absorb light between 450 and 650 nm, making them efficient and versatile light-harvesting systems. However, basic research and technological innovations are needed, not only to understand their role in photosynthesis but also to realise the potential applications of PBSs. Synthetic biology provides an innovative approach to expand our understanding of the distinctive properties that make the PBS such an efficient light-harvesting system and to explore its heterologous synthesis, photosynthetic functions and potential medical applications. Focusing on these topics, this review describes the essential components needed for PBS assembly, the functional basis of PBS photosynthesis and the applications of phycobiliproteins. Moreover, key technical challenges for heterologous biosynthesis of phycobiliproteins in chassis cells are discussed.
ARTICLE | doi:10.20944/preprints202305.0522.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Amygdalin; cassava; phytochemistry; biological activities; Benin
Online: 8 May 2023 (10:45:35 CEST)
: Given that cancer is a disease that is rampant in the world and especially in Africa where the population has enormous difficulty in treating it, plants are a safer and less expensive alterna-tive. Cassava is one of the plant species valued in Benin because of its numerous medicinal and nutritional virtues. This study evaluated the biological activities of amygdalin from the organs of three cassava varieties most produced in Benin (BEN, RB, and MJ). HPLC analysis was used to quantify amygdalin in cassava organs and derivatives. Phytochemical screening was performed to determine secondary metabolite groups. DPPH and FRAP methods were used to assess anti-oxidant activity. Cytotoxicity of the extracts was tested on Artemia salina larvae. The an-ti-inflammatory activity was evaluated in vivo on albino mouse paw edema model induced by 5% formalin. The anticancer activity was evaluated in vivo on Wistar rats rendered cancerous by 1,2-dimethylhydrazine (DMH) using 5-fluorouracil as reference molecule. The results showed that the organs of all three-cassava varieties contained glycosides, flavonoids, saponosides, ster-oids, tannins, coumarins, and cyanogenic derivatives. Young stems and fresh leaves of cassava had the highest amygdalin concentration with 11142.99 µg 10 g-1 and 9251.14 µg 10 g-1 respec-tively. The Agbeli derivative was more concentrated in amygdalin with a content of 401.56 µg 10 g-1 than the others derivatives. The antioxidant activity results showed that the amygdalin ex-tracts were found to be DPPH radical scavengers with IC50 values ranging from 0.18 mg mL-1 to 2.35 mg mL-1. The cytotoxicity test showed no toxicity of the extracts toward shrimp larvae. Ad-ministration of amygdalin extracts from the leaves of BEN and MJ varieties prevents inflamma-tory edema. The percentages of edema inhibition varied between 21.77% and 27.89%. These val-ues are similar (p> 0.05) to that of acetylsalicylic acid (25.20%). Amygdalin extract of BEN variety significantly (p<0.0001) reduces edema. Cancer induction with DMH was inhibited by both BEN extract. In both preventive and curative treatments, rats fed with amygdalin extracts showed low anti-cancer activity under the effect of DMH and the significant difference in biochemical results. Thus, the organs of all three cassava varieties studied have secondary metabolites and good an-tioxydant activity. The leaves contain high levels of amygdalin and can be used as an-ti-inflammatory and anticancer agents.
ARTICLE | doi:10.20944/preprints202305.0482.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Mitochondria; Personalized Oncology; cancer stem cell; T Cell
Online: 8 May 2023 (08:48:56 CEST)
Energy is needed by cancer cells to stay alive and communicate with their surroundings. The primary organelles for cellular metabolism and energy synthesis are mitochondria. Researchers recently proved that cancer cells can steal immune cells' mitochondria using nanoscale tubes. This finding demonstrates the dependence of cancer cells on normal cells for their living and function. It also denotes the importance of mitochondria in cancer cells’ biology. Emerging evidence has demonstrated how mitochondria are essential for cancer cells to survive in the harsh tumor microenvironment, evade the immune system, obtain more aggressive features, and resist treatments. For instance, functional mitochondria can improve cancer resistance against radiotherapy by scavenging the released reactive oxygen species. Therefore, targeting mitochondria can potentially enhance oncological outcomes, according to this notion. The patients' reactions to radiation are varied, ranging from a complete response to even cancer progression during treatment. This concept illustrates how different levels of mitochondrial metabolism might contribute to this heterogeneity. Considering this notion can help to improve personalized oncological treatments. This article outlines the importance of mitochondrial metabolism in cancer biology and personalized treatments.
HYPOTHESIS | doi:10.20944/preprints202305.0415.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: evolution of the ribosome; evolution of life; genetic code; evolution of translation; origins of protein biosynthesis; RNA machines; RNA world; origin of life
Online: 6 May 2023 (10:26:26 CEST)
Translation of the genetic code into proteins is the main process across all life and ribosomes are ancient cellular machines uniquely enabling this information transformation. We provide a brief overview of the recent advances in linking the ribosomal structure and evolution. Based on these insights into ribosomal organisation across time, we propose that early replication and protein biosynthesis functions were inseparable and in fact were performed by the same ancient RNA molecule, the riboreplisome. Riboreplisome hypothesis helps to address issues of non-Darwinian evolution and complicated starting point that are characteristic to the RNA world, protein world and RNA:protein mixed co-development theories. We suggest that the riboreplisome is the missing link and a molecular machine connecting chemical and biological evolution paths, by being capable of basic genetic and feature selection functions in a cell- or cell-free setting. The riboreplisome hypothesis allows ease of sequential, genetically uninterrupted emergence and sophistication of the genetic code and its decoding machinery, and provides plausible explanations to the origins of the three main RNA types involved in the decoding: the ribosomal, transfer and messenger RNA. Furthermore, riboreplisome can help explaining the co-evolution of aminoacylation machinery, the driving force behind selective gene transcription and expression, and the cell-like compartmentalisation. While we may never find the original riboreplisome again, we might continue to discover different molecular remnants of its prior existence across the existing biological RNA, which, once identified or resurrected, can be useful in synthetic biology applications.
ARTICLE | doi:10.20944/preprints202305.0409.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: smoking,; DNA methylation; cardiometabolic traits; mendelian randomization
Online: 6 May 2023 (09:56:37 CEST)
Understanding epigenome paths through which smoking contributes to cardiometabolic traits is important for downstream applications. In this study, I used a SNP-based analytical pipeline to integrate several publicly available datasets and identify CpG sites that mediate the impact of smoking on cardiometabolic traits. After applying stringent statistical criteria, 11 CpG sites were detected that showed significant association (P<5e-8) with cardiometabolic traits at both discovery and replication stage. By integrating eQTL data, I identified genes behind a number of these associations. cg05228408 was hypomethylated in smokers and contributed to higher blood pressure by lowering the expression of CLCN6 gene. cg08639339 was hypermethylated in smokers and lowered metabolic rate by increasing the expression of RAB29; furthermore, I noted TMEM120A mediated the impact of smoking-cg17325771 on LDL, and LTBP3 mediated the smoking-cg07029024 effect on heart rate. This study provides a list of CpG sites that mediates the impact of smoking on cardiometabolic traits and a framework to investigate epigenome path through which a lifestyle habit modifies disease risks.
COMMUNICATION | doi:10.20944/preprints202305.0396.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: CRCLM; vessel co-option; angiogenesis; neutrophil; TGFβ1; apoptosis
Online: 6 May 2023 (08:51:29 CEST)
Vessel co-option correlates with resistance against anti-angiogenic agents and chemotherapy in colorectal cancer liver metastasis (CRCLM). We previously identified higher intensity of neutrophils in the tumour microenvironment of vessel co-opting CRCLM lesions compared to their angiogenic counterparts. Herein, we demonstrated that over 50% of the neutrophils in vessel co-opting lesions are expressing pro-apoptotic markers including cleaved caspase-3 and poly (ADP-ribose) polymerase-1 (PARP-1). Our previous publications suggested upregulation of transforming growth factor-beta (TGFβ1) in the microenvironment of vessel co-option CRCLM. Therefore, we examined the effect of TGFβ1 on the expression of cleaved caspase-3 and PARP-1 in neutrophils in vitro. Significantly, we noticed the upregulation of pro-apoptotic markers upon exposure to TGFβ1. This finding might pave the way to determine the role of neutrophils in developing vessel co-option in CRCLM in the future.
REVIEW | doi:10.20944/preprints202305.0368.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: SNAREs; Rabs; neurotransmitter release; myelin
Online: 5 May 2023 (13:44:10 CEST)
The nervous system is composed of neurons, which conduct the signals, and glial cells that provide metabolic and functional support and protection to neurons. An important component of the nervous system is the myelin sheath, an insulating layer around the nerves of the brain and spinal cord, which allows a fast and efficient nerve conduction and therefore the proper transmission of signal to all tissues and organs. Myelin is made of protein and fatty substances and gives protection for the propagation of the electrical impulse. Myelin alterations determine the onset of several neuropathies as the electrical signal can be slowed or stopped. Myelin is formed by oligodendrocytes in the central nervous system (CNS) and by Schwann cells in the peripheral nervous system (PNS). Differences in myelination in the CNS and PNS have been found and molecules involved in membrane trafficking such as SNAREs and rabs have been proved to contribute to several aspects regarding the formation of myelin or dysmyelination. Here, I will describe the role of these proteins in regulating membrane trafficking and nerve conduction, myelin biogenesis and maintenance.
ARTICLE | doi:10.20944/preprints202305.0364.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: K-Ras; centrin; calmodulin; mitosis; centrosome; BRET
Online: 5 May 2023 (11:41:23 CEST)
Recent data suggest that K-Ras4B (hereafter K-Ras) can drive cancer cell stemness via calmodulin (CaM)-dependent, non-canonical Wnt-signalling. Here we examined whether another Ca2+-binding protein, the CaM-related centrin1, binds to K-Ras and could mediate some K-Ras functions that were previously ascribed to CaM. While CaM and centrin1 appear to distinguish between peptides that were derived from their classical targets, they both bind to K-Ras in cells. Cellular BRET-data suggest that CaM engages more with K-Ras than centrin1 and that the interaction with the C-terminal membrane anchor of K-Ras is sufficient for this. Surprisingly, binding of neither K-Ras nor its membrane anchor alone to CaM or centrin1 is sensitive to inhibition of prenylation. In support of an involvement of the G-domain of K-Ras in cellular complexes with these Ca2+-binding proteins, we find that oncogenic K-RasG12V displays increased engagement with both CaM and centrin1. This is abrogated by addition of the D38A effector-site mutation, suggesting that K-RasG12V is held together with CaM or centrin1 in complexes with effectors. When treated with CaM-inhibitors the BRET-interaction of K-RasG12V with centrin1 was also disrupted in the low micromolar range, comparable to that with CaM. While CaM predominates in regulating functional membrane anchorage of K-Ras, it has a very similar co-distribution with centrin1 on mitotic organelles. Given these results, a significant overlap of the CaM- and centrin1-dependent functions of K-Ras is suggested.
ARTICLE | doi:10.20944/preprints202305.0326.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: RNA-Seq; run-off in vitro transcription; RNA polymerase; sigma factor; TSS; promoter
Online: 5 May 2023 (07:54:09 CEST)
We developed and applied a method for characterizing bacterial promoters genome-wide by in vitro transcription coupled to transcriptome sequencing specific for native 5’-ends of transcripts. This method called ROSE (Run-Off transcription/RNA-SEquencing), only requires chromosomal DNA, ribonucleotides, RNA polymerase (RNAP) core enzyme, and a specific sigma factor, recognizing the corresponding promoters, which have to be analyzed. ROSE was performed on E. coli K-12 MG1655 genomic DNA using E. coli RNAP holoenzyme (including σ70) and yielded 3,226 transcription start sites, 2,167 of which were also identified in in vivo studies, and 598 were new. Many new promoters not yet identified by in vivo experiments might be repressed under the tested conditions. Complementary in vivo experiments with E. coli K-12 strain BW25113 and isogenic transcription factor gene knockout mutants of fis, fur, and hns were used to test this hypothesis. Comparative transcriptome analysis demonstrated that ROSE could identify bona fide promoters that were apparently repressed in vivo. In this sense, ROSE is well-suited as a bottom-up approach for characterizing transcriptional networks in bacteria and ideally complementary to top-down in vivo transcriptome studies.
ARTICLE | doi:10.20944/preprints202305.0302.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Mitochondria; Eclipsed protein targeting; Yeast model system; TDH1; TDH2; Dual protein tar-geting
Online: 5 May 2023 (04:57:13 CEST)
Dual localization or dual targeting refers to the phenomenon by which identical, or almost identical, proteins are localized to two (or more) separate compartments of the cell. From previous work in the field, we had estimated that a third of the mitochondrial proteome is dual targeted to extra-mitochondrial locations and suggested that this abundant dual targeting presents an evolutionary advantage. Here we set out to study how many additional proteins whose main activity is outside mitochondria are also localized, albeit at low levels, to mitochondria (eclipsed). To do this we employed two complementary approaches utilizing the α-complementation assay in yeast to uncover the extent of such eclipsed distribution: one systematic and unbiased and the other based on Mitochondrial Targeting Signal (MTS) predictions. Using these approaches, we suggest 280 new eclipsed distributed protein candidates. Interestingly, these proteins are enriched for distinctive properties compared to their exclusively mitochondrial-targeted counterparts. We focus on one unexpected eclipsed protein-family of the Triose-phosphate DeHydrogenases (TDH), and prove that indeed their eclipsed distribution in mitochondria is important for mitochondrial activity. Our work provides a paradigm of deliberate eclipsed mitochondrial localization, targeting and function, and should expand our understanding of mitochondrial function in health and disease.
ARTICLE | doi:10.20944/preprints202305.0281.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Antibody; PG16; HIV-1; peptides; antibody mimetic peptides; molecular dynamics
Online: 5 May 2023 (03:08:46 CEST)
PG16 is a broadly neutralizing antibody that binds to the gp120 subunit of the HIV-1 Env protein. The major interaction site is formed by the unusually long complementarity determining region (CDR) H3. The CDRH3 residue Tyr100H is known to represent a tyrosine sulfation site; however, this modification is not present in the experimental complex structure of PG16 with full-length HIV-1 Env. To investigate the role of sulfation for this complex, we modeled the sulfation of Tyr100H and compared the dynamics and energetics of the modified and unmodified complex by atomistic molecular dynamics simulations. Our results show that sulfation does not affect the overall conformation of CDRH3, but still enhances gp120 interactions both at the site of mutation and for the neighboring residues. This stabilization affects not only protein-protein contacts, but also the interactions between PG16 and the gp120 glycan shield. Further, we also investigated whether PG16-CDRH3 is a suitable template for the development of peptide mimetics. For a peptide spanning residues 93-105 of PG16 we obtained an experimental EC50 value of 3nM for the binding of gp120 to the peptide. This affinity can be enhanced by almost one order of magnitude by artificial disulfide bonding between residues 99 and 100F. In contrast, any truncation results in significantly lower affinity, suggesting that the entire peptide segment is involved in gp120 recognition. Their high affinity makes PG16-derived peptides useful building blocks for further optimization to obtain a potent inhibitor that efficiently blocks HIV-1 infection.
ARTICLE | doi:10.20944/preprints202305.0072.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: APOBEC3A; carcinogenesis; DNA deamination; DNA mutation, hepatocellular carcinoma; molecular mechanism; RNA editing; tumorigenesis
Online: 2 May 2023 (08:12:34 CEST)
Although the APOBEC3 family of single-stranded DNA cytosine deaminases are well-known as antiviral factors, these enzymes are rapidly gaining attention as prominent sources of mutation in cancer. APOBEC3 signature single base substitutions, C-to-T and C-to-G in TCA and TCT motifs, are evident in over 70% of human malignancies and dominate the mutational landscape of numerous individual tumors. Recent murine studies have established cause-and-effect relationships, with both human APOBEC3A and APOBEC3B proving capable of promoting tumor formation in vivo. Here, we investigate the molecular mechanism of APOBEC3A-driven tumor development using the murine Fah liver complementation and regeneration system. First, we show that APOBEC3A alone is capable of driving tumor development (without Tp53 knockdown as in prior studies). Second, we show that the catalytic glutamic acid residue of APOBEC3A (E72) is required for tumor formation. Third, we show that an APOBEC3A separation-of-function mutant with compromised DNA deamination activity and wildtype RNA editing activity is defective in promoting tumor formation. Collectively, these results indicate that APOBEC3A is a “master driver” that fuels tumor formation through a DNA deamination-dependent mechanism.
ARTICLE | doi:10.20944/preprints202305.0026.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: alternariol, steroidogenesis, mycotoxin, carcinogenesis, dehydroepiandrosterone
Online: 1 May 2023 (11:08:44 CEST)
The mycotoxin alternariol (AOH) can be found in the food products infected by Alternaria spp. and is considered an endocrine-disruptive mycotoxin. The main mechanism of AOH toxicity is associated with DNA damage and modulation of the inflammation process. Nevertheless, AOH is considered as one of the emerging mycotoxins. In this study we evaluated how AOH might affect a local steroidogenesis process in prostate, in both normal as well as cancer cells. We observed that AOH itself modulates the cell cycle, inflammation and apoptosis rather than steroidogenesis process in prostate cancer cells; however, in the presence of the other steroidogenic agent, the effect is significant. Therefore, this is the first study to report the effect of AOH on local steroidogenesis in normal and prostate cancer cells. We postulate that AOH might modulate the release of the steroid hormones and expression of the key components by interfering with the steroidogenic pathway and might be considered a steroidogenesis-altering agent.
ARTICLE | doi:10.20944/preprints202304.1265.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: amyloid bodies; intrinsically disordered protein; liquid-liquid phase separation; membrane-less organelle; nuclear stress bodies; nucleolar biomolecular condensates
Online: 30 April 2023 (05:18:24 CEST)
Radical changes in the idea of the organization of the intracellular space that occurred in the early 2010-s made it possible to consider the formation and functioning of the so-called membrane-less organelles (MLOs) based on a single physical principle: the liquid-liquid phase separation (LLPS) of biopolymers. Weak nonspecific inter- and intramolecular interactions of disordered polymers, primarily of intrinsically disordered proteins and RNA, play a central role in the initiation and regulation of these processes. On the other hand, in some cases, the "maturation" of MLOs can be accompanied by the "liquid-gel” phase transition, where other types of interactions can play a significant role in reorganization of their structure. In this work, we conducted a bioinformatics analysis of the propensity of the proteomes of two membrane-less organelles formed in response to stress in the same compartment, nucleolus, for spontaneous phase separation and looked at their intrinsic disorder predispositions. These nucleolar MLOs, amyloid bodies (A-bodies) formed in the response to acidosis and heat shock and nuclear stress bodies (nSBs), are characterized by the partially overlapping composition, but show different functional activities and morphologies. We show that the proteomes of these nucleolar biocondensates are differently enriched in proteins, many of with high potential for spontaneous LLPS that correlates with different morphology and function of these organelles. The results of these analyses allowed us to evaluate the role of weak interactions in the formation and functioning of these important organelles.
ARTICLE | doi:10.20944/preprints202304.1259.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: rice false smut; quantitative loop-mediated isothermal amplification (q-LAMP); detection; ustiloxins biosynthetic gene
Online: 30 April 2023 (04:40:34 CEST)
Rice false smut caused by Ustilaginoidea virens is one of the most devastating diseases on rice worldwide, which results in serious reduction of rice quality and yield. As an airborne fungal disease, early diagnosis of rice false smut, monitoring the epidemics and distribution of its pathogens, is particularly important to management the infection. In this study, a quantitative loop-mediated isothermal amplification (q-LAMP) method for the U. virens detection and quantifying was developed. This method has higher sensitivity and efficiency compared to quantitative real-time PCR (q-PCR) method. The species-specific primer sets UV-2 used was design based on the unique sequence of U. virens ustiloxins biosynthetic gene (NCBI accession number: BR001221.1). The q-LAMP assay was able to detect a concentration of 6.4 spores/mL at an optimal reaction temperature of 63.4℃ within 60 min. Moreover, the q-LAMP assay can even achieve accurate quantitative detection when there were only 9 spores on the tape. A linearized equation for the standard curve, y =-0.2866x + 13.829 (x is the amplification time, the spore number = 100.65y), was established for detection and quantifying of U. virens. In field detection applications, this q-LAMP method is more accurate and faster than traditional observation method. Collectively, this study has established a powerful and simple monitoring tool for U. virens, which provide valuable technical supports for forecast and management of rice false smut, and theoretical basis for precise fungicide application.
ARTICLE | doi:10.20944/preprints202304.1105.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: citrate cycle; fructose and mannose pathway; glycolysis/gluconeogenesis pathway; Il17b; Ngf; Nfe2l2; pmm1; pmm2; pyruvate metabolism; Slc2a1
Online: 28 April 2023 (04:22:40 CEST)
The high morbidity and mortality rate of the pulmonary arterial hypertension (PAH) is partially explained by the metabolic deregulation associated with the disease. The present study identified statistically significant increase of the glucose transporter solute carrier family 2 (Slc2a1), beta nerve growth factor (Ngf), and nuclear factor erythroid derived 2, like 2 (Nfe2l2) on three standard PAH rat models and their healthy counterpart. PAH was induced by subjecting the animals to hypoxia (HO group) or by injecting them with monocrotaline in either normal (CM) or hypoxic (HM) atmospheric conditions. The Western blot and double immunofluorescent experiments were complemented with the gene expression profiling of the animal lungs analyzed from the perspective of the Genomic Fabric Paradigm. We found substantial remodeling of the genomic fabrics of the citrate cycle, pyruvate metabolism, glycolysis/gluconeogenesis and fructose and manose pathways. According to the novel transcriptomic distance criterion, the most comprehensive measure of the transcriptomic alteration, glycolysis/gluconeogenesis was the most affected functional pathway in all three PAH models. PAH decoupled the coordinated expression of many metabolic genes and replaced Pmm2 with Pmm1 in the center of the fructose and mannose metabolism. Our data show that metabolic dysregulation is a major pathogenic factor of the PAH.
REVIEW | doi:10.20944/preprints202304.1092.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Diabetes mellitus; antidiabetic activity; in vitro; in vivo; assays
Online: 28 April 2023 (03:23:54 CEST)
Diabetes mellitus is a global health issue that necessitates the development of novel therapeutic approaches. Today numerous experimental methods have been used and set up to evaluate novel drugs with antidiabetic effects. In addition, several research studies have been done to induce diabetes under in vitro and in vivo conditions, but only a small number of these efforts are currently in a usable stage. This review aims to provide useful guidance for researchers who seek to evaluate the antidiabetic potential of drugs, agents, or new medications using the standard methods published by authorities and academics worldwide organizations and research centers. In this review, we collected 132 relevant articles from prominent databases such as PubMed, ScienceDirect, Scopus and others to summarize in vitro and in vivo experimental validation of antidiabetic treatment from 1943 to present.
ARTICLE | doi:10.20944/preprints202304.0984.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: CYSTM; manganese; stress; MNC1; YDR034W-B; yeast
Online: 26 April 2023 (11:47:06 CEST)
The CYSTM (cysteine-rich transmembrane module) protein family comprises small molecular cysteine-rich tail-anchored membrane proteins found in many eukaryotes. The Saccharomyces cerevisiae strains carrying the CYSTM genes YDRO34W-B and YBR056W-A (MNC1) fused with GFP were used to test expression of these genes under different stresses. The YBR056W-A (MNC1) and YDR034W-B genes are expressed under stress conditions caused by the toxic concentrations of heavy metal ions such as manganese, cobalt, nickel, zinc, cuprum, and 2.4-dinitrophenol uncoupler. YDR034W-B but not YBR056W-A is expressed under alkali and cadmium stresses. YBR056W-A is localized in intracellular membranes, while YDR034W-B is localized in the cytoplasmic membrane. The null-mutants in both genes demonstrated both decreased cell concentration and lytic phenotype when cultivated in the presence of excess manganese. This indicates the involvement of Mnc1 and YDR034W-B proteins in manganese detoxification, probably by complexation of its ion.
REVIEW | doi:10.20944/preprints202304.0819.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: PDT; Nitric oxide; iNOS/NO induction; Bystander effects
Online: 24 April 2023 (04:26:43 CEST)
Recent studies have revealed that several cancer cell types can upregulate inducible nitric oxide synthase (iNOS) and iNOS-derived nitric oxide (NO) after a moderate photodynamic challenge sensitized by 5-aminolevulinic acid (ALA)-induced protoporphyrin-IX. The NO signaled for cell resistance to photokilling as well as greater growth and migration/invasion aggressiveness of surviving cells. On this basis, it was predicted that diffusible NO from PDT-targeted cells in a tumor might enhance growth, migration, and invasiveness of non- or poorly PDT-targeted bystander cells. This was tested using a novel approach in which ALA-PDT targeted cancer cells on a culture dish were initially segregated from non-targeted bystander cells of the same type via impermeable silicone-rimmed rings. Several hours after LED irradiation, the rings were removed, and both cell populations analyzed in the dark for various responses. After a moderate extent of targeted cell killing (~25%), bystander proliferation and migration were evaluated, and both were found to be significantly enhanced. Enhancement corelated with iNOS/NO upregulation in surviving PDT-targeted cancer cells in the following cell type order: PC3 > MDA-MB-231 >U87 > BLM. If occurring in an actual PDT-challenged tumor, such bystander effects might compromise treatment efficacy by stimulating tumor growth and/or metastatic dissemination. Possible mitigation of these negative effects by using pharmacologic inhibitors of iNOS expression or activity as PDT adjuvants will be discussed.
REVIEW | doi:10.20944/preprints202304.0798.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Head and neck cancer; oral mucositis; pain; genomics; transcriptomics; microbiomics
Online: 23 April 2023 (12:29:17 CEST)
Oral mucositis (OM) is inflammation of the mouth caused by damage to the mucous membranes that line the mouth and throat. It is a side effect of cancer treatment, particularly in patients with head and neck squamous cell carcinoma (HNSCC) who undergo radiotherapy, chemotherapy, and/or immunotherapy with immune checkpoint inhibitors. The etiology and pathogenic mechanisms of OM is complex and multifaceted, involving cytotoxicity (cell death), inflammation, infection, change in microbiome, and immune-mediated cytotoxicity. We summarize the literature about attempts to use various omics methodologies (genomics, transcriptomics, microbiomics and metabolomics) to elucidate the biological pathways associated with the development or the severity of OM. Integrating different omics into multi-omics approaches carries the potential to discover links among host factors (genomics), host responses (transcriptomics, metabolomics), and local environment (microbiomics).
ARTICLE | doi:10.20944/preprints202304.0792.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Axenic culture; Aroma genes; Central metabolism; Fermentation; Morphological characterization; Secondary metabolite clusters; Strain isolation; Transcriptome profile; Truffle cultivation; Vegetative mycelium
Online: 23 April 2023 (08:21:55 CEST)
Truffles are ascomycete hypogeous fungi belonging to the Tuberaceae family of the Pezizales order that grow in ectomycorrhizal symbiosis with tree roots and are known for their peculiar aromas and flavors. Axenic culture of truffle mycelium is problematic because it is not possible in many cases, and the growth rate is meager when it is possible. This limitation prompts searching and characterizing new strains that can be handled in laboratory conditions for basic and applied studies. In this work, a new strain of Tuber borchii (strain SP1) has been isolated and cultured, and its transcriptome has been analyzed under different in vitro culture conditions. The results show that the best T. borchii SP1 growth was obtained using maltose-enriched cultures made with soft-agar and in static submerged cultures made at 22ºC. The transcriptome analysis of this strain cultured in different media indicated that most of the gene transcription effort is due to a limited number of genes (20% of genes account for 80% of the transcription), that the transcription profile of the central metabolism genes was similar in the different conditions analyzed with a transcription signal detected for around 80% of the annotated genes. The gene expression profile suggests that T. borchii uses a fermentative rather than respiratory metabolism, even in aerobic conditions. Finally, there is a reduced expression of genes belonging to secondary metabolite clusters, whereas there is a significative transcription of those involved in producing volatile aromatic compounds.
REVIEW | doi:10.20944/preprints202304.0209.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Gut microbiome; Machine learning; Deep learning; Metagenomics; Autoimmune diseases; Biomarkers discovery; Diagnostic models
Online: 23 April 2023 (02:59:58 CEST)
The makeup of human microbiota has been linked to a number of autoimmune disorders. Recent developments in whole metagenome sequencing and 16S rRNA sequencing technology have considerably aided research into the microbiome and its relationship to disease. Due to the inherent high dimensionality and complexity of data generated by high-throughput platforms, conventional bioinformatics techniques could only provide an inadequate explanation for the most relevant changes and seldom provide correct predictions. Machine learning, on the other hand, is a subset of artificial intelligence applications that enable the untangling of high-dimensional systems and intricate knots in correlation by learning complex patterns and improving automatically from training data without being explicitly programmed. Machine learning is increasingly being utilized to research the influence of microbes on the onset of illness and other clinical features since computer power has increased dramatically in the last few decades. In this review paper, we focused on emerging methodological approaches of supervised machine learning algorithms for identification of autoimmune disorders utilizing metagenomics data, as well as the potential benefits and limitations of machine learning models in clinical applications.
ARTICLE | doi:10.20944/preprints202304.0650.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: malignant melanoma; liver metastasis; cytokines; IL11RA; hepatic endothelial cells
Online: 20 April 2023 (10:30:39 CEST)
Cytokines and chemokines (chemotactic cytokines) are soluble extracellular proteins that bind to specific receptors and play an integral role in the cell-to-cell signaling network, in addition can promote the homing of cancer cells into different organs. We investigated the potential relationship between human hepatic sinusoidal endothelial cells (HHSECs) and several melanoma cell lines for the expression of chemokine and cytokine ligand and receptor expression during invasion of melanoma cells. In order to define the invasion related gene expression differences, we selected invasive and non-invasive subpopulations of cells after co-culturing with HHSECs. In addition, we determined protein expression of the endothelial cells before and after co-culturing with melanoma cell lines originated from primary tumors. Cell lines with increased invasive capacity after culturing with conditioned medium showed a set of receptor genes (CXCR1, IL1RL1, IL1RN, IL3RA, IL8RA, IL11RA, IL15RA, IL17RC, and IL17RD) with significantly different expression. It is very important note, that the IL11RA gene expression level was also significantly increased in primary melanoma tissues with liver metastasis as well. Proteome arrays revealed 15 differentially expressed proteins (including CD31, VCAM-1, ANGPT2, CXCL8, and CCL20) in the hepatic endothelial cells after co-cultured with melanoma cells. Our findings clearly indicate the interaction between liver endothelial- and melanoma cells. Based on our data, we assume that overexpression of the IL11RA gene might has key role in the formation of organ specific metastasis to the liver by primary melanoma cells.
ARTICLE | doi:10.20944/preprints202304.0607.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Metformin; HIV transcription and replication; transactivation; gene expression; CREB phosphorylation; HIV LTR promoter
Online: 20 April 2023 (05:24:55 CEST)
Antiretroviral therapy has effectively suppressed HIV infection and replication and prolonged the lifespan of HIV-infected individuals. In the meantime, various complications including type 2 diabetes associated with long-term antiviral therapy have shown steady increases. Metformin has been the front-line anti-hyperglycemic drug of choice and the most widely prescribed medication for the treatment of type 2 diabetes. However, little is known about the effects of Metformin on HIV infection and replication. In this study, we showed that Metformin treatment enhanced HIV gene expression and transcription in HIV-transfected 293T and HIV-infected Jurkat and human PBMC. Moreover, we demonstrated that Metformin treatment resulted in increased CREB expression and phosphorylation, and TBP expression. Furthermore, we showed that Metformin treatment increased the recruitment of phosphorylated CREB and TBP to the HIV LTR promoter. Lastly, we showed that inhibition of CREB activation significantly abrogated Metformin-enhanced HIV gene expression. Taken together, these results demonstrated that Metformin treatment increased HIV transcription, gene expression, and production though increased CREB phosphorylation and recruitment to the HIV LTR promoter. These findings may help design the clinical management plan and HIV cure strategy of using metformin to treat type 2 diabetes, a comorbidity with an increasing prevalence, in people living with HIV.
ARTICLE | doi:10.20944/preprints202304.0601.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: FTSJ1; methyltransferase; tRNA; readthrough; stop codon mutation; small molecules; docking; molecular dynamics; MM-GBSA
Online: 20 April 2023 (03:21:07 CEST)
Cystic Fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene, coding for the CFTR chloride channel. About 10% of the CFTR gene mutations are "stop" mutations, which generate a Premature Termination Codon (PTC), thus synthesizing a truncated CFTR protein. A way to bypass PTC relies on ribosome readthrough, which is the ribosome’s capacity to skip a PTC, thus generating a full-length protein. “TRIDs” are molecules exerting ribosome readthrough; for some, the mechanism of action is still under debate. We investigate a possible mechanism of action (MOA) by which our recently synthesized TRIDs, namely NV848, NV914, and NV930, could exert their readthrough activity by in silico analysis and in vitro studies. Our results suggest a likely inhibition of FTSJ1, a tryptophan tRNA-specific 2’-O-methyltransferase.
ARTICLE | doi:10.20944/preprints202304.0566.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: anticancer agents; microtubules; molecular docking; Plagiochila species; plagiochilin A; α-tubulin.
Online: 19 April 2023 (07:59:13 CEST)
Among bryophytes, the Plagiochila genus represents a large group of leafy liverworts, with over 500 species. Plagiochilins A-to-X are sesquiterpenoids isolated from Plagiochila species. The lead compound plagiochilin A (Plg-A), endowed with anticancer and anti-parasitic properties, has been characterized as a potent mitosis inhibitor, acting selectively at the late stage of cytokinesis termed abscission. The compound perturbs the dynamic of microtubules, blocking cell cycle progression and triggering the death of malignant cells. Based on the compound mechanism of action and the analogy with other natural products bearing a dihydro-pyrone moiety, we postulated that Plg-A could bind to the pironetin site of α-tubulin. A molecular docking analysis has been performed to compare binding of all 24 plagiochilins to α-tubulin and to establish structure-binding relationships. The identification of Plg-E and Plg-G as the best binders in the series pointed out to the importance of the C13-OH or C=O group for α-tubulin recognition. This observation led to the testing of the natural product ester plagiochilin A-15-yl n-octanoate and the corresponding alcohol (Plg-OH), both identified as robust α-tubulin binders. The study provides a rational to explain potentially the mechanism of action of Plg-A and to guide the design of new derivatives.
ARTICLE | doi:10.20944/preprints202304.0539.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: adeno-associated virus; metachromatic leukodystrophy; arylsulfatase A; gene therapy; central nervous system; peripheral nervous system; neurodegeneration
Online: 19 April 2023 (04:17:50 CEST)
Metachromatic leukodystrophy (MLD) is a hereditary neurodegenerative disease characterized by demye-lination and motor and cognitive impairment due to the deficiency of the lysosomal enzyme arylsulfatase A (ARSA) or the saposin B activator protein (SapB). Current treatments are limited; however, gene therapy using adeno-associated virus (AAV) vectors for ARSA delivery has shown promising results. The main challenges for MLD gene therapy include optimizing AAV dosage, selecting the most effective serotype, and determining the best route of administration for ARSA delivery into the central nervous system. This study aims to evaluate the safety and efficacy of AAV serotype 9 encoding ARSA (AAV9-ARSA) gene therapy when administered intrave-nously or intrathecally in minipigs, a large animal model with anatomical and physiological similarities to humans. By comparing these two administration methods, this study contributes to the understanding of how to improve the effectiveness of MLD gene therapy and offers valuable insights for future clinical applications.
ARTICLE | doi:10.20944/preprints202304.0522.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: ORF7b; SARS-CoV-2; COVID-19; 3D-structure; molecular dynamics; dipole vector; Electrostatic properties of alpha-helix.
Online: 18 April 2023 (11:14:01 CEST)
ORF7b-2 is an accessory protein of the SARS-CoV-2 virus of only 43 amino acids. It has been implicated in various functional hypotheses, some of which predict its involvement as a trans-membrane protein. In this study, ORF7b-2 has often been compared to ORF7b-1 of the SARS virus to highlight differences and similarities with a protein that should have a similar biological role. Structural analysis of ORF7b-2 and its electrostatic characteristics show a polypeptide with both ends negatively charged and a diffuse negative charge over the entire structure. Therefore, its behavior in solution is like that of a weak negative polyelectrolyte, more precisely a polyanion with a net charge of – 4 at neutral pH. Its structure was modeled with two different modeling systems, one of which was ab initio. The two best models are similar, as confirmed by the Ramachandran plot, and show a central alpha-helical structure with two disordered and mobile ends. A normal mode analysis characterized the low-frequency dynamic aspects of the protein. The analysis of the structural shows a rigid central segment with mobile and fluctuating extremities, involved in a conformational equilibrium of the helix ↔ coil type. The calculation of the dipole moment shows its vector is not aligned with the main axis of the structure with an outward tilt of 24°. Molecular dynamics simulations were also conducted and the one in water is in good agreement with the previous results. While, the simulation performed by inserting a pre-oriented dimer (OMP) into a solvated lipid showed the low tendency of the protein to solvate in the apolar environment of the membrane. ORF7b-2 also shows a widespread distribution of negative surfaces that dynamically adjust to changes in structural organization. The BioGrid platform's [Biological General Repository for Interaction Datasets] through the BioGrid COVID-19 Coronavirus Curation Project shows a very large number of experimentally proven physical interactions unique to ORF7b-2, some of them with cytoplasmic proteins. These features of ORF7b-2, evaluated together, suggest a remarkable propensity of ORF7b-2 to interact with multiple molecular partners on both an electrostatic and hydrophobic basis. All this makes it unreasonable that the only biological function of this protein should be that exerted as an intramembrane protein.
ARTICLE | doi:10.20944/preprints202304.0476.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: arrestin; structure-function; GPCR; receptor binding; protein-protein interactions
Online: 18 April 2023 (04:02:29 CEST)
Arrestin-1, or visual arrestin, exhibits an exquisite selectivity for light-activated phosphorylated rhodopsin (P-Rh*) over its other functional forms. That selectivity is believed to be mediated by two well-established structural elements in the arrestin-1 molecule, the activation sensor detecting the active conformation of rhodopsin and the phosphorylation sensor responsive to the rhodopsin phosphorylation, which only active phosphorylated rhodopsin can engage simultaneously. However, in the crystal structure of the arrestin-1-rhodopsin complex there are arrestin-1 residues located close to rhodopsin, which do not belong to either sensor. Here we tested by site-directed mutagenesis the functional role of these residues in wild type arrestin-1 using direct binding assay to P-Rh* and light-activated unphosphorylated rhodopsin (Rh*). We found that many mutations either enhanced the binding only to Rh* or increased the binding to Rh* much more than to P-Rh*. The data suggest that the native residues in these positions act as binding suppressors, specifically inhibiting the arrestin-1 binding to Rh* and thereby increasing arrestin-1 selectivity for P-Rh*. This calls for the modification of a widely accepted model of the arrestin-receptor interactions.
ARTICLE | doi:10.20944/preprints202304.0439.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Adipogenesis; RBMS1; RNA-binding proteins; Lipid metabolism
Online: 17 April 2023 (10:09:50 CEST)
Adipocytes play a critical role in maintaining a healthy systemic metabolism by storing and releasing energy in the form of fat and helping to regulate glucose and lipid levels in the body. Adipogenesis is the process through which pre-adipocytes are differentiated into mature adipocytes. It is a complex process involving various transcription factors and signaling pathways. Dysregulation of adipogenesis has been implicated in the development of obesity and metabolic disorders. Therefore, understanding the mechanisms that regulate adipogenesis and the factors that contribute to its dysregulation may provide insights into the prevention and treatment of these conditions. RNA Binding Motif Single Stranded Interacting Protein 1 (RBMS1) is a protein that binds to RNA and plays a critical role in various cellular processes such as alternative splicing, mRNA stability, and translation. The RBMS1 polymorphism has been shown to be associated with obesity and Type 2 diabetes, but the role of RBMS1 in adipose metabolism and adipogenesis is not known. We show that RBMS1 is highly expressed during the early phase of differentiation of the murine adipocyte cell line 3T3-L1 and is significantly upregulated in adipose tissue depots and adipocytes of high-fat-fed mice, implying a possible role in adipogenesis and adipose metabolism. Knockdown of RBMS1 in pre-adipocytes impacted the differentiation process and reduced the expression of some of the key adipogenic markers. Transcriptomic and proteomic analysis indicated that RBMS1 depletion affected the expression of several genes involved in major metabolic processes, including carbohydrate and lipid metabolism. Our findings imply that RBMS1 plays an important role in adipocyte metabolism and may offer novel therapeutic opportunity for metabolic disorders such as obesity and type 2 diabetes.
ARTICLE | doi:10.20944/preprints202304.0404.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: ctDNA; liquid biopsy; Methylation; SDHCa; RDBPb; Pheochromocytoma; Paraganglioma
Online: 17 April 2023 (04:54:45 CEST)
Introduction: Circulating tumor DNA (ctDNA) is newly diagnosed tumor DNA that can easily represent a tumor’s genetic and epigenetic change. Pheochromocytomas (PCCs) and Paragangliomas (PGLs) are rare tumors of adrenal gland tissue that have the potential to be detected by ctDNA. We aimed to study the potential of the methylation status of RDBP, SDHB, and SDHC genes in ctDNA of PCCs/PGLs patients as a diagnostic biomarker. Materials and Methods: Clinical data, fresh frozen tissue, the blood of 12 PCCs/PGL patients, and the blood of 12 age/sex-matched normal patients were collected. The methylation status of RDBP, SDHB, and SDHC was compared between cases and controls by MS-HRM analysis. Results: Amongst six promoter regions of RDBP, SDHB, and SDHC, promoter methylation quantification of SDHCa and RDBPb was significantly different between PCCs/PGLs and controls. SDHCa was methylated in 49.93% of PCCs/PGLs cases vs. 8.33 % of control samples, p-value: 0.026, area under curve AUC=0.757, and RDBPb in 74.9% of PCCs/PGLs cases vs. 25.0% of control samples, p-value: 0.032, AUC=0.750. Conclusions: This study suggests the ctDNA potential for a less invasive source of tumor epigenetic modification in PCCs/PGLs malignancies. The SDHCa and RDBPb hypermethylation warrant further exploration as diagnostic tools for PCCs/PGLs.
ARTICLE | doi:10.20944/preprints202304.0397.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: erythrocyte, non alcoholic steatohepatitis, immunometabolism; thrombospondin-1; arginase-1; phosphatidylethanolamine; metabolic inflammation
Online: 17 April 2023 (04:22:12 CEST)
Background: Hepatic erythrophagocytosis is augmented in NASH and amplifies inflammation and fibrosis. Although various pro-phagocytic signals have been identified on erythrocytes of NASH patients, the role of bound thrombospondin-1 (TSP-1), which acts as an “eat-me” signal, arginase-1, which regulates the levels of nitric oxide in erythrocytes, and phosphatidylethano-lamine (PE) which can amplify erythrophagocytosis and hepatic inflammation have not been explored. Hence, we sought to investigate the levels of arginase-1 and TSP-1 in erythrocyte lysate and PE in erythrocyte membranes of NASH patients. Methods: Twenty-four patients and 14 healthy controls participated in our study. The levels of TSP-1 and arginase were quantified by ELISA in erythrocyte lysates, and the levels of PE in erythrocyte membranes by thin layer chro-matography. Results: Erythrocytes of NAFLD patients exhibit lower levels of arginase-1 and TSP-1 (p<0.01). Erythrocyte-bound TSP-1 levels correlated with the levels of erythrocyte surface CD47. Phosphatidylethanolamine was increased in erythrocytes of NASH patients and was accompanied by increased release, indicating exposure. Conclusion: Our results imply reduced TSP-1 binding by erythrocytes which could allow free TSP-1 molecules to act on macrophages, enhancing erythrophagocytosis. Increased PE which could amplify inflammation after efferocytosis, while downregulation of arginase-1 could lead to defective efferocytosis.
ARTICLE | doi:10.20944/preprints202304.0383.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: brain maturation; glucocorticoid receptor; post-traductional modification; one-carbone metabolism; homocysteine
Online: 17 April 2023 (03:28:12 CEST)
Vitamin B9(folate)/B12 deficiency is known to induce brain structural and/or functional retardations. Besides neural tube defects in case of major consequences, several mild deregulations also lead to deleterious effect after birth, and folate supplementation recommended in some countries usually stop at the end of the first trimester. Various hormonal receptors were shown to be deregulated in brain tissue under this context. The glucocorticoid receptor (GR) is particularly sensitive to epigenetic regulation and post-traductional modifications. In a mother-offspring rat model of vitamin B9/B12 deficiency, we investigated whether a prolonged folate supplementation could restore the GR signalization in the hypothalamus. Our data showed that a deficiency in folate and vitamin B12 during the in-utero and the early postnatal periods was associated with reduced GR expression inn the hypothalamus. We also described for the first time a new post-traductional modification of GR that impaired ligand binding and GR activation, leading to decreased the expression of one of the GR targets in the hypothalamus, AgRP. Moreover, this brain-impaired GR pathway was associated with behavioral perturbations during offspring growth. Importantly, perinatal and postnatal supplementation with folic acid helped restore GR mRNA level and activity in hypothalamus cells and improved behavioral deficits.
ARTICLE | doi:10.20944/preprints202304.0327.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Ovarian cancer; PARP inhibitors; epithelial to mesenchymal transition; drug response
Online: 13 April 2023 (14:30:07 CEST)
Epithelial ovarian cancer (EOC) remains the most lethal gynecologic malignancy, largely due to metastasis and drug resistant recurrences. Fifteen percent of ovarian tumors carry mutations in BRCA1 or BRCA2, rendering them vulnerable to treatment with PARP inhibitors such as olaparib. Recent studies have shown that TGFβ can induce “BRCAness” in BRCA wild-type cancer cells. Given that TGFβ is a known driver of epithelial to mesenchymal transition (EMT), and the con-nection between EMT and metastatic spread in EOC and other cancers, we asked if TGFβ and EMT alter susceptibility of EOC to PARP inhibition. Epithelial EOC cells were transiently treated with soluble TGFβ and their clonogenic potential, expression and function of EMT and DNA repair genes, and response to PARP inhibitors compared with untreated controls. A second epithelial cell line was compared to its mesenchymal derivative for EMT and DNA repair gene expression and drug responses. We found that TGFβ and EMT resulted in downregulation of genes responsible for homologous recombination (HR) and sensitized cells to olaparib. HR efficiency was reduced in a dose-dependent manner. Furthermore, mesenchymal cells displayed sensitivity to olaparib, cis-platin, and the DNA-PK inhibitor Nu-7441. Therefore, treatment of disseminated, mesenchymal tumors may represent an opportunity to expand clinical utility of PARP inhibitors and similar agents.
REVIEW | doi:10.20944/preprints202301.0257.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Gene expression; transcriptome diversity; transcriptional variation; transcript diversity; isoform-level diversity; gene-level diversity
Online: 13 April 2023 (03:07:07 CEST)
Following the central dogma of molecular biology, gene expression heterogeneity can aid in predicting and explaining the wide variety of protein products, functions, and, ultimately, heterogeneity in phenotypes. There is currently overlapping terminology used to describe the types of diversity in gene expression profiles, and overlooking these nuances can misrepresent important biological information. Here, we describe transcriptome diversity as a measure of the heterogeneity in 1) the expression of all genes within a sample or a single gene across samples in a population (gene-level diversity) or 2) the isoform-specific expression of a given gene (isoform-level diversity). We first overview modulators and quantification of transcriptome diversity at the gene level. Then, we discuss the role alternative splicing plays in driving transcript isoform-level diversity and how it can be quantified. Additionally, we overview computational resources for calculating gene-level and isoform-level diversity for high-throughput sequencing data. Finally, we discuss future applications of transcriptome diversity. This review provides a comprehensive overview of how gene expression diversity arises, and how measuring it determines a more complete picture of heterogeneity across proteins, cells, tissues, organisms, and species.
REVIEW | doi:10.20944/preprints202304.0273.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: non-Saccharomyces yeasts; wine; yeasts
Online: 12 April 2023 (11:55:00 CEST)
Wine is a processed beverage that offers high nutritional and health benefits. It is produced from grape must, which undergoes fermentation by yeasts (and sometimes lactic acid bacteria) to create a product that is highly appreciated by consumers worldwide. However, if only one type of yeast, specifically Saccharomyces cerevisiae, were used in the fermentation process, the resulting wine would lack aroma and flavor and may be rejected by consumers. To produce wine with a desirable taste and aroma, non-Saccharomyces yeasts are necessary. These yeasts contribute volatile aromatic compounds that significantly impact the wine’s final taste. They promote the release of primary aromatic compounds through a sequential hydrolysis mechanism involving several glycosidases unique to these yeasts. This review will discuss the unique characteristics of these yeasts (Schizosaccharomyces pombe, Pichia kluyveri, Torulaspora delbrueckii, Wickerhamomyces anomalus, Metschnikowia pulcherrima, Hanseniaspora vineae, Lachancea thermotolerans, Candida stellata, and others) and their impact on wine fermentations and co-fermentations. Their existence and the metabolites they produce enhance the complexity of wine flavor, resulting in a more enjoyable drinking experience.
ARTICLE | doi:10.20944/preprints202304.0270.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Clostridium septicum; fractioned-extracellular proteins; macrophages; cell death; apoptosis; autophagy
Online: 12 April 2023 (10:27:17 CEST)
The induction of macrophage death is regarded as a potential mechanism by which components secreted by Clostridium septicum are used to evade the innate immune response and cause tissue damage. This study aimed to determine the effect of partially purified fractions of extracellular proteins secreted by C. septicum on the death of mouse peritoneal macrophages. Elicited mouse peritoneal macrophages were incubated with partially purified fractions of proteins secreted by C. septicum into culture medium. After incubation, we found that the protein fraction with a molecular weight ≥ 100 kDa caused significant cell death in macrophages, changed cell morphology, increased markers of apoptosis and autophagy, and increased the expression (protein and mRNA) of IL-1 and TNFα. Our data suggest that the proteins secreted by C. septicum (MW ≥100kDa) induce cell death in macrophages by promoting autophagy-triggered apoptosis. This may contribute to our understanding of the molecular mechanism of immune evasion by C. septicum at the infection site.
ARTICLE | doi:10.20944/preprints202304.0195.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: artificial intelligence; protein structure; protein modeling; nanobody; antibody
Online: 11 April 2023 (05:13:24 CEST)
The number of applications for nanobodies is steadily expanding, positioning these molecules as fast-growing biologic products in the biotechnology market. Several of their applications require protein engineering, which in turn would greatly benefit from having a reliable structural model of the nanobody of interest. However, as with antibodies, structural modeling of nanobodies is still a challenge. With the rise of artificial intelligence (AI), several methods have been developed in recent years that attempt to solve the problem of protein modeling. In this study, we have compared the performance in nanobody modeling of several state-of-the-art AI-based programs, either designed for general protein modeling, such as AlphaFold2, OmegaFold, ESMFold and Yang-Server, or specifically designed for antibody modeling, such as IgFold, and Nanonet. While all these programs performed rather well in constructing the nanobody framework and CDRs 1 and 2, modeling of CDR3 sill represents a big challenge. Interestingly, tailoring an AI method for antibody modeling does not necessarily translate into better results for nanobodies.
REVIEW | doi:10.20944/preprints202304.0143.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Genome stability; DNA replication; DNA repair; lagging strand DNA synthesis; Okazaki fragments; initiation; DNA polymerase α; DNA primase; CTC1-STN1-TEN1 complex; SV40 T antigen; CMG complex
Online: 10 April 2023 (04:20:27 CEST)
The term ‘Hallmarks of Cancer’ was coined by Hanahan and Weinberg in their influential reviews and they described genome instability as a property of cells enabling cancer development [1, 2]. Accurate DNA replication of genomes is central to diminish genome instability. Here, the understanding of the initiation of DNA synthesis in origins of DNA replication to start leading strand synthesis and the initiation of Okazaki fragment on the lagging strand are crucial to control genome instability. Recent findings have provided new insights into the mechanism of the remodelling of the prime initiation enzyme, DNA polymerase α-primase, during primer synthesis, how the enzyme complex achieves lagging strand synthesis, and how it is linked to replication forks to achieve optimal initiation of Okazaki fragments. Moreover, the central roles of RNA primer synthesis by Pol-prim in multiple genome stability pathways such as replication fork restart and protection of DNA against degradation by exonucleases during double-strand break repair is discussed.
REVIEW | doi:10.20944/preprints202304.0036.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Chromolaena odorata; liver; breast; cancer; plant
Online: 4 April 2023 (04:37:21 CEST)
Siam weed, scientifically known as Chromolaena odorata and belonging to the Asteraceae family, is a fast-growing plant with prolific seed production. Although it is a traditional medicinal plant, it has become an agricultural weed in Africa and Asia, posing a threat to biodiversity and causing environmental damage. Despite this, C. odorata is highly regarded as a medicinal herb in tropical Africa, with anticancer effects on breast, liver, and colorectal cancer. However, it is important to regulate the intake of the plant extract as it can have a hepatotoxic effect on liver cells at higher doses. Further research needs to be conducted on the plant extract, and proper orientation and knowledge of its oral daily administration are necessary. This review summarizes current scientific investigations using ethanolic and methanolic aqueous extracts of C. odorata leaves on various cancer cells, to uncover its potential as an anticancer agent. The investigations were sourced from online databases like Google Scholar, PubMed, and other online-based journals.
ARTICLE | doi:10.20944/preprints202304.0002.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: trastuzumab; trastuzumab resistance; HER2; breast cancer; proteomic analysis; metabolic reprogramming.
Online: 3 April 2023 (02:19:25 CEST)
The antibody Trastuzumab (Tz) targeting ERBB2 has improved the prognosis of patients with breast cancer (BCa) that overexpress this receptor. Resistance to Tz negatively impacts prognosis. Several mechanisms have been reported to cause Tz resistance. The objective of this study was to identify common mechanisms in in vitro models of acquired BCa Tz resistance. In particular, we used three widely available ERBB2+ BCa cell lines adapted to grow in Tz. We performed several analyses to address possible changes in phenotype, proliferation, and ERBB2 membrane expres-sion common to the three Tz-R cell lines compared to wt, but none was found. High-resolution mass spectrometry analysis identified, instead, a common set of differentially expressed proteins (DEPs) in Tz-R vs. wt cells. Furthermore, bioinformatic tools revealed that all three Tz-R cell models shared a modulation of proteins involved in the metabolism of lipids, organophosphate biosynthetic process, and macromolecule methylation. Ultrastructural analysis confirmed altera-tion of lipid droplets in resistant cells. Our data strongly support the hypothesis that complex metabolic adaptation, including lipid metabolism, protein phosphorylation, and possibly chro-matin remodeling, may fuel Tz resistance. The identification of a common set of 10 DEPs in all three TZ-resistant cell lines may provide novel targets for therapeutic intervention.
ARTICLE | doi:10.20944/preprints202303.0543.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Alzheimer disease; cathepsin D; Cre-Lox technology; CRISPR; gene regulation; tetracycline regulatory element.
Online: 31 March 2023 (05:46:41 CEST)
Commonly employed methods for reversibly disrupting gene expression, such as those based on RNAi or CRISPRi, are rarely capable of achieving >80-90% downregulation, making them unsuitable for targeting genes that require more complete disruption to elicit a phenotype. Genetic deletion, on the other hand, while enabling complete disruption of target genes, often produces undesirable irreversible consequences such as cytotoxicity or cell death. Here we describe the design, development and detailed characterization of a dual-function "TRE-Lox" system for effecting either (a) doxycycline (Dox)-mediated downregulation or (b) genetic deletion of cathepsin D (CatD), based on targeted insertion of a tetracycline-response element (TRE) and two LoxP sites into the 5' end of the endogenous gene (CTSD). Using an optimized reverse-tetracycline transrepressor (rtTR) variant fused with the Krüppel-associated box (KRAB) domain, we show that CatD expression can be disrupted by as much as 98% in mouse embryonic fibroblasts (MEFs). This system is highly sensitive to Dox (IC50 = 1.46 ng/mL) and results in rapid (t1/2 = 0.57 d) and titratable downregulation of CatD. Notably, even near-total disruption of CatD expression was completely reversed by withdrawal of Dox. As expected, transient expression of Cre recombinase results in complete deletion of the CTSD gene. The dual functionality of this novel system will facilitate future studies of the involvement of CatD in various diseases, particularly those attributable to partial loss of CatD function. In addition, the TRE-Lox approach should be applicable to the regulation of other target genes requiring more complete disruption than can be achieved by traditional methods.
ARTICLE | doi:10.20944/preprints202303.0385.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: True definition of cosmic red shift; Hubble-Hawking universe; Light speed expansion; Light speed rotation; Cosmic halt with quantum physics
Online: 22 March 2023 (02:36:13 CET)
We appeal the science community to review the basic definition of wavelength dependent cosmic red shift. We would like to emphasize the point that, the true cosmic red shift must be defined as the ratio of loss in energy of photon to the energy of photon at galaxy. In terms of wavelength, photon red shift must be defined as the ratio of change in wavelength to the observed wavelength of photon. Considering the recent paper pertaining to cosmic halt authored by Cosmin Andrei, Anna Ijjas, and Paul J. Steinhardt and reviewed by Saul Perlmutter, in this paper we propose a very simple model of the universe having early stage light speed expansion and current stage quantum halt accompanied by light speed rotation. In this context, representing early cosmic expansion and rotation as an outward spiral, it seems possible to consider Hubble’s law as a representation of current cosmic rotation having no further expansion. To understand the current cosmic halt, we are proposing very simple and very strange atomic and nuclear relations that constitute Hubble parameter and gravitational constant. It needs further study, observations and analysis.
COMMUNICATION | doi:10.20944/preprints202303.0373.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: ischemia; cardiovascular disease; diabetes; obesity; galectins
Online: 21 March 2023 (07:56:47 CET)
Background Epidemiological studies have associated plasma galectin-4 (Gal-4) levels with prevalent and incident diabetes, and with increased risk of coronary artery disease, but data regarding possible associations with stroke are lacking. Methods We tested Gal-4 association with prevalent stroke in a population-based cohort, and whether Gal-4 increases after ischemic stroke in mice fed a high-fat diet (HFD). Results Gal-4 was higher in subjects with compared to without prevalent ischemic stroke, and was associated with prevalent ischemic stroke (odds ratio 1.52; 95% confidence interval 1.01-2.30; p=0.048) adjusted for age, sex and covariates of cardiometabolic health. Plasma Gal-4 increased after stroke in both controls and HFD-fed mice, but HFD exposure was devoid of impact in Gal-4 levels. Conclusions This study demonstrates higher plasma Gal-4 levels in both a stroke mouse model and individuals with prevalent stroke.
ARTICLE | doi:10.20944/preprints202303.0315.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Type I nitroreductase; NfsB; Crystal structure; Prodrug; Metronidazole; Targeted cellular ablation; Tinidazole; CB1954; Dinitrotoluene
Online: 17 March 2023 (03:22:59 CET)
Bacterial nitroreductase enzymes that convert prodrugs to cytotoxins are valuable tools for creating transgenic targeted ablation models to study cellular function and cell-specific regeneration paradigms. We recently engineered a nitroreductase (“NTR 2.0”) for substantially enhanced reduction of the prodrug metronidazole, which permits faster cell ablation kinetics, cleaner interrogations of cell function, ablation of previously recalcitrant cell types, and extended ablation paradigms useful for modelling chronic diseases. To provide insight into the enhanced enzymatic mechanism of NTR 2.0, we have solved the X-ray crystal structure at 1.85 Angstroms resolution and compared it to the parental enzyme, NfsB from Vibrio vulnificus. We additionally present a survey of reductive activity with eight alternative nitroaromatic substrates, to provide access to alternative ablation prodrugs, and explore applications such as remediation of dinitrotoluene pollutants. The predicted binding modes of four key substrates were investigated using molecular modelling.
COMMUNICATION | doi:10.20944/preprints202303.0309.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: mouse CCR6; monoclonal antibody; epitope; ELISA; SPR
Online: 16 March 2023 (14:13:28 CET)
CC chemokine receptor 6 (CCR6) is one of the members of G protein-coupled receptor (GPCR) family that is upregulated in many immune-related cells, including B lymphocytes, effector and memory T cells, regulatory T cells, and immature dendritic cells. Coordination between CCR6 and its ligand CC motif chemokine ligand 20 (CCL20) is deeply involved in the pathogenesis of various diseases, such as cancer, autoimmune diseases, and psoriasis. Therefore, CCR6 is an attractive target for therapy and is being investigated as a diagnostic marker for patients. In a previous study, we developed an anti-mouse CCR6 (mCCR6) monoclonal antibody (mAb), C6Mab-13 (rat IgG1, kappa), applicable for flow cytometry by immunizing a rat with N-terminal peptide of mCCR6. This study investigated the binding epitope of C6Mab-13 using enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) methods with the synthesized point mutated-peptides within 1-20 amino acids region of mCCR6. In ELISA, C6Mab-13 lost the reaction to the alanine-substituted peptide of D11A. The epitope of C6Mab-13 was identified to be Asp11 in ELISA. Furthermore, in SPR analysis, the dissociation constants (KD) could not be calculated for G9A and D11A mutants due to lack of binding. The SPR analysis demonstrated that the C6Mab-13 epitope comprises Gly9 and Asp11. Taken together, the key binding epitope of C6Mab-13 was determined to be around Asp11 on mCCR6. Based on the epitope information, C6Mab-13 could be useful for further functional analysis of mCCR6 in future studies.