REVIEW | doi:10.20944/preprints202206.0103.v1
Subject: Life Sciences, Immunology Keywords: cell death; death receptors; viral infection; signaling; regulated cell death
Online: 7 June 2022 (10:09:11 CEST)
The fate of a viral infection in the host begins with various types of cellular responses, such as abortive, productive, latent, and destructive infections. Apoptosis, necroptosis, and pyroptosis are the three major types of regulated cell death mechanisms that play critical roles in viral infection response. Cell shrinkage, nuclear condensation, bleb formation, and retained membrane integrity are all signs of osmotic imbalance-driven cytoplasmic swelling and early membrane damage in necroptosis and pyroptosis. Caspase-driven apoptotic cell demise is considered in many circum-stances as an anti-inflammatory, and some pathogens hijack the cell death signaling routes to initiate a targeted attack against the host. In this review, we selected mechanisms by which viruses interfere with cell death are discussed in-depth and are used to illustrate the general principles and cellular signaling mechanisms of virus-host specific molecule interactions.
SHORT NOTE | doi:10.20944/preprints202003.0014.v1
Online: 1 March 2020 (13:28:26 CET)
Lewis et al. published an important and timely necessary article about the determination of death by neurological criteria, revising the Uniform Determination of Death.The acceptance of brain death (BD) has been progressively accepted beginning at the late 1950s. Nonetheless, contentious brain-death cases have recently raised new controversies about the diagnosis of BD, such as the Jahi McMath case, extensively covered by the US and international press. Jahi McMath meant a terrible tragedy for her and her family. But further than this gloomy story, the case has also raised confusion and challenging qualms about a fundamental query: how we confirm whether a person is dead or alive? Since 1981, the Uniform Determination of Death Act (UDDA) has served as the legal foundation for the medical practice of determining death. But, although death by neurologic criteria is considered legal death throughout the United States, several recent lawsuits have quizzed the rightfulness the authority of the UDDA to declare death by neurological criteria. This issue explains the importance of Lewis’s et al. paper. In this article I want to present the historical procedure for issuing a law in Cuba for the determination and certification of death. Of course, it is impossible to compare our country with USA. Cuba is a small and developing country, in which a law encompasses a national scenery, in contrast with USA, a multistate nation.
SHORT NOTE | doi:10.20944/preprints202007.0526.v1
Subject: Social Sciences, Other Keywords: COVID-19; Unreported COVID-19 Death; Provisional COVID-19 Death; Death Reporting Discrepancy; Bangladesh
Online: 22 July 2020 (11:32:05 CEST)
Objective: We aim to assess the reporting discrepancy and the difference between confirmed and unreported COVID-19-like death counts.Study Design: The study is based on time-series data.Methods: We used publicly available data to explore the differences between confirmed death counts and deaths with Codiv-19 symptoms between March 8, 2020, and July 11, 2020, in Bangladesh.Results: During the week ending May 9, 2020, the unreported COVID-19-like death count was higher than the confirmed COVID-19 death count; however, it was lower in the following weeks. On average, unreported COVID-19-like death counts were similar to the confirmed COVID-19 death counts during the same period. However, the reporting authority neither considers these deaths nor adjusts for potential seasonal influenza or other related deaths, which might produce incomplete COVID-19 data and respective mortality rates. Conclusions: Documenting unreported deaths with COVID-19 symptoms needs to be included in provisional death counts because it is essential to estimate a robust COVID-19 mortality rate and to offer data-driven pandemic response strategies. An urgent initiative is needed to prepare an acceptable guideline for COVID-19 death reporting.
REVIEW | doi:10.20944/preprints202301.0264.v1
Subject: Life Sciences, Biochemistry Keywords: mitochondrial cell death; autophagy cell death; lipidomic analysis; drug development
Online: 16 January 2023 (03:37:34 CET)
Different studies corroborate a role for ceramide synthases and their downstream products, ceramides, in modulation of apoptosis and autophagy in the context of cancer. These mechanisms of regulation, however, appear to be context dependent in terms of ceramides’ fatty acid chain length, subcellular localization, and the presence or absence of their downstream targets. Our current understanding of the role of ceramide synthases and ceramides in regulation of apoptosis and autophagy could be harnessed to pioneer the development of new treatments to activate or inhibit a single type of ceramide synthase, thereby regulating the apoptosis induction or cross talk of apoptosis and autophagy in cancer cells. Moreover, the apoptotic function of ceramide suggests that ceramide analogues can pave the way for the development of novel cancer treatments. Therefore, in the current review paper we discuss the impact of ceramide synthases and ceramides in regulation of apoptosis and autophagy in context of different types of cancers. We also briefly introduce the latest methods to analyze the lipids in biological samples. Finally, we discuss the drug development strategies focusing on the ceramide synthases and ceramides as future therapeutic approaches in cancer therapy.
REVIEW | doi:10.20944/preprints202003.0228.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: Immunogenic cell death; DAMPs; cell death resistance; immunotherapy; combination therapy
Online: 13 March 2020 (10:04:56 CET)
Cell death resistance is a key feature of tumor cells. One of the main anti-cancer therapies is increasing the susceptibility of cells to death. Cancer cells have developed a capability of tumor immune escape. Hence, restoring the immunogenicity of cancer cells can be suggested as an effective approach against cancer. Accumulating evidence proposes that several anticancer agents provoke the release of danger-associated molecular patterns (DAMPs) that are determinants of immunogenicity and stimulate immunogenic cell death (ICD). It has been suggested that ICD inducers are two different types according to their various activities. Here, we review the well-characterized DAMPs and focus on the different types of ICD inducers and recent combination therapies that can augment the immunogenicity of cancer cells.
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: Brain death; posterior fossa; brainstem death; ancillary tests; EEG; evoked potentials
Online: 3 August 2020 (01:22:49 CEST)
Background: New controversies have raised on brain death (BD) diagnosis when lesions are localized in the posterior fossa. Objective: To discuss the particularities of diagnosis BD in patients with posterior fossa lesions. Material and Methods. The author made a systematic review of literature on this topic. Results and Conclusions: A supratentorial brain lesion usually produces a rostrocaudal transtentorial brain herniation, resulting in forebrain and brainstem loss of function. In secondary brain lesions [i.e., cerebral hypoxia], the brainstem is also affected like the forebrain. Nevertheless, some cases complaining posterior fossa lesions [i.e., basilar artery thrombotic infarcts, or hemorrhages of the brainstem and/or cerebellum] may retain intracranial blood flow and EEG activity. In this article I discuss that if a posterior fossa lesion does not produce an enormous increment of intracranial pressure, a complete intracranial circulatory arrest does not occur, explaining the preservation of EEG activity, evoked potentials, and autonomic function. I also address Jahi McMath, who was declared braindead, but ancillary tests, performed 9 months after initial brain insult, showed conservation of intracranial structures, EEG activity, and autonomic reactivity to “Mother Talks” stimulus, rejecting the diagnosis of BD. Jahi McMath’s MRI study demonstrated a huge lesion in the pons. Some authors have argued that in patients with primary brainstem lesions it might be possible to find a in some cases partial recover of consciousness, even fulfilling clinical BD criteria. This was the case in Jahi McMath.
REVIEW | doi:10.20944/preprints202109.0063.v1
Online: 3 September 2021 (13:13:48 CEST)
P53 is known as the most critical tumor suppressor and is often referred to as the guardian of our genome. More than 40 years after its discovery, we are still struggling to understand all molecular details on how this transcription factor prevents oncogenesis or how to leverage current knowledge about its function to improve cancer treatment. Multiple cues, including DNA-damage or mitotic errors, can lead to the stabilization and nuclear translocation of p53, initiating the expression of multiple target genes. These transcriptional programs may well be cell type and stimulus-specific, as is their outcome that ultimately imposes a barrier to cellular transformation. Cell cycle arrest and cell death are two well-studied consequences of p53 activation, but, while being considered as critical, they do not fully explain the consequences of p53 loss-of-function phenotypes in cancer. Here, we discuss how mitotic errors alert the p53 network and give an overview on multiple ways how p53 can trigger cell death. We argue that a comparative analysis of different types of p53 responses, elicited by different triggers in a time-resolved manner in well-defined model systems is critical to understand cell type specific cell fate induced by p53 upon its activation, in order to resolve the remaining mystery of its tumor suppressive function.
REVIEW | doi:10.20944/preprints202105.0053.v1
Online: 5 May 2021 (12:38:56 CEST)
Necroptosis is an inflammatory form of lytic programmed cell death that is thought to have evolved to defend against pathogens. Genetic deletion of the terminal effector protein – MLKL – shows no overt phenotype in the C57BL/6 mouse strain under conventional laboratory housing conditions. Small molecules that inhibit necroptosis by targeting the kinase activity of RIPK1, one of the main upstream conduits to MLKL activation, have shown promise in several murine models of non-infectious disease and in phase II human clinical trials. This has triggered multi-billion-dollar investments into the emerging class of necroptosis blocking drugs, and the potential utility of targeting the terminal effector is being closely scrutinised. Here we review murine models of disease, both genetic deletion and mutation, that investigate the role of MLKL. We summarize a series of examples from several broad disease categories including ischemia reperfusion injury, sterile inflammation, pathogen infection and haematological stress. Elucidating MLKL’s contribution to mouse models of disease is an important first step to identify human indications that stand to benefit most from MLKL-targeted drug therapies.
REVIEW | doi:10.20944/preprints202112.0484.v1
Online: 30 December 2021 (12:32:40 CET)
Cell death by apoptosis is a major cellular response, in the control of tissue homeostasis and as a defense mechanism in case of cellular aggression like an infection. Cell self-destruction is part of antiviral responses, aimed at limiting the spread of a virus. Although it may contribute to the deleterious effects in infectious pathology, apoptosis remains a key mechanism for viral clearance and resolution of infection. The control mechanisms of cell death processes by viruses have been extensively studied. Apoptosis can be triggered by different viral determinants, through different pathways, as a result of virally induced cell stresses and innate immune responses. Zika virus (ZIKV) induces Zika disease in humans which has caused severe neurological forms, birth defects and microcephaly in newborns during the last epidemics. ZIKV also surprised by revealing an ability to persist in the genital tract and in semen, thus being sexually transmitted. Mechanisms of diverting antiviral responses such as the interferon response, the role of cytopathic effects and apoptosis in the etiology of the disease have been widely studied and debated. In this review, we examined the interplay between ZIKV infection of different cell types and apoptosis and how the virus deals with this cellular response. We illustrate a duality in the effects of ZIKV-controlled apoptosis, depending on whether it occurs too early or too late, respectively in neuropathogenesis, or in long-term viral persistence. We further discuss a prospective role for apoptosis in ZIKV-related therapies, and the use of ZIKV as an oncolytic agent.
ARTICLE | doi:10.20944/preprints202302.0044.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: Brain death diagnosis; Intracranial Pressure; Intracranial compliance
Online: 2 February 2023 (11:30:01 CET)
Background: Due to the importance of brain death (BD) diagnostic do not mistake, reliable confirmatory exams should be performed to enhance its security. This study aims to evaluate the intracranial pressure (ICP) pulse morphology behavior in brain-dead patients through a noninvasive monitoring system. Methods: A pilot case-control study was conducted in adults that met the BD national protocol criteria. Quantitative data from the ICP waveforms were extracted and analyzed comparing BD patients and health subjects. Results: Fifteen patients were included. ICP waveforms presented substantial differences amidst BD patients when compared to the control group. Moreover, pulse amplitude and time to peak variables values in the case group were also statistically significant. Conclusions: In this exploratory study, noninvasive ICP waveforms have shown potential as a screening method in patients with suspected brain death. Future studies should be carried out in a larger population.
ARTICLE | doi:10.20944/preprints202301.0261.v1
Subject: Life Sciences, Virology Keywords: Arboviruses; Histopathology; Cell death; Necrosis; Steatosis; Liver
Online: 16 January 2023 (02:55:43 CET)
Arboviruses such as yellow fever virus (YFV), dengue virus (DENV), and chikungunya virus (CHIKV) presenting wide global dissemination and the pathogenic profile developed in infected individuals, which develop from nonspecific clinical conditions to severe forms, characterized by the promotion of significant lesions in different organs of the harborer, culminating in multiple organ dysfunction. To characterize, quantify, and compare the patterns of histopathological alterations in human liver samples from patients with yellow fever (YF), dengue fever (DF), and chikungunya fever (CF). Analytical cross-sectional study by histopathological analysis with 70 samples of liver patients, collected from 2000 to 2017, with confirmed laboratory diagnosis who died due to infection and complications by the YF, DF, and CF. Of the histopathological findings in human liver samples there was a significant difference between the control and infection groups, with a predominance of alterations in the midzonal area of the three cases analyzed, among the arboviruses studied, the hepatic involvement in cases of YF showed greater intensity of histopathological changes. Among the alterations evaluated, cell swelling, microvesicular steatosis and apoptosis were classified as degree of tissue damage from severe to very severe. The pathological abnormalities associated with infection by YFV, DENV, and CHIKV showed predominance of changes in the midzonal area. We also noted that in among of the arboviruses studied, liver involvement in cases of YFV infection was more intense.
REVIEW | doi:10.20944/preprints202202.0219.v1
Subject: Life Sciences, Biochemistry Keywords: mitochondria; ATP synthase; cell death; neurodegenerative diseases.
Online: 18 February 2022 (02:13:31 CET)
The ATP synthase is a mitochondrial complex embedded in the inner mitochondrial membrane. The enzyme is under the double genetic control of the mitochondrial DNA (mtDNA) and nuclear DNA (nDNA). Fatal human diseases have been associated with defects in ATP synthase (Complex V) activity linked to mtDNA or nDNA pathogenetic variants in genes encoding structural subunits or assembly factors. Mitochondrial post-translational modifications of key amino acids, reduced/increased subunit expression, or protein to protein ATP synthase interaction, are also some of the mechanisms involved in the age-related disease pathway. All the major neurodegenerative diseases: Parkinson’s, Alzheimer’s and motor neuron diseases such as Amyotrophic Lateral Sclerosis highlight an impaired ATP generation in a mechanism involving the permeability transition pore that triggers a cellular homeostasis failure responsible for different forms of regulated cell death. In this review, we will explore ATP synthase assembly and function in physiological and pathological conditions by referring to the recent cryo-EM studies and by exploring human diseases models.
ARTICLE | doi:10.20944/preprints202102.0552.v1
Subject: Keywords: modified SIR model, epidemic, death and source.
Online: 24 February 2021 (15:59:09 CET)
The original purpose of this article was to modify the original SIR equations to allow for a direct source of infection (without which the original equations would have no solutions unless one starts with an already infected population) and also to see to what extent one could obtain multiple outbreaks of an infectious disease. In the course of developing the basic ideas several other factors arose to take prominent roles.Perhaps one of the more salient factors is the point that choosing an arbitrary time to change conditions from say a lock-down for the population to a less stringent social behavior, such as allowing partial or complete opening of businesses and schools, etc. should be based on knowledge of the disease and its evolution. Such decisions are usually made by politicians who have less than full information concerning the consequences of their actions. Several examples are given to illustrate these points.
ARTICLE | doi:10.20944/preprints202012.0376.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Desipramine; Autophagy; Apoptosis; Death receptor-5; TRAIL
Online: 15 December 2020 (12:09:09 CET)
Autophagy, an alternative cell death mechanism, is also termed programmed cell death type II. Autophagy in cancer treatment needs to be regulated. In our study, autophagy inhibition by desipramine or the autophagy inhibitor chloroquine (CQ) enhanced tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor-2 [death receptor (DR5)] expression and subsequently TRAIL-induced apoptosis in TRAIL-resistant A549 lung cancer cells. Genetic inhibition of DR5 substantially reduced desipramine-enhanced TRAIL-mediated apoptosis, proving that DR5 was required to increase TRAIL sensitivity in TRAIL-resistant cancer cells. Desipramine treatment upregulated p62 expression and promoted conversion of light chain 3 (LC3)-I to its lipid-conjugated form, LC3-II, indicating that autophagy inhibition occurred at the final stages of autophagic flux. Transmission electron microscopy analysis showed the presence of condensed autophagosomes, which resulted from the late stages of autophagy inhibition by desipramine. TRAIL, in combination with desipramine or CQ, augmented the expression of apoptosis-related proteins cleaved caspase-8 and cleaved caspase-3. Our results contributed to the understanding of the mechanism underlying the synergistic anti-cancer effect of desipramine and TRAIL and presented a novel mechanism of DR5 upregulation. These findings demonstrated that autophagic flux inhibition by desipramine potentiated TRAIL-induced apoptosis, suggesting that appropriate regulation of autophagy is required for sensitizing TRAIL-resistant cancer cells to TRAIL-mediated apoptosis.
Subject: Medicine & Pharmacology, General Medical Research Keywords: articles; bibliometric; causes; death; diseases; journals; Russia
Online: 23 September 2020 (04:48:32 CEST)
Societal changes have had effects on deaths from all causes in Russia. Up until now, deaths from all causes have been well researched, although several inconsistencies persist on the contributions of researchers. This study assessed research output, trends and topics that shaped deaths from all causes studies in Russia. Using bibliometric and topic modelling approaches, deaths from all causes in Russia published from 1914 to date was analysed using data on publications, citations, journals, keywords co-occurrence, year of publication, institutional affiliations, and country of origin from Scopus. Overall results indicate a steady growth of publications in Russia was documented after 1985. The h-index of some top 10 authors did not surpass single digits. A network visualisation map showed that ‘Russia’, ‘male’, ‘mortality’ and ‘human’ were the most commonly encountered vital terms. Of the ten most prolific authors, McKee M, Shkolnikov VM, Bobak M, Samorodskaya IV and Andreev E were the first five. Although the top 10 journals researching on death causes in Russia were Russian, these journals were not included in the most cited journals. The most prolific institutions studying deaths in Russia included; Tehran University of Medical Sciences, London School of Hygiene and Tropical Medicine, University College London, Max Planck Institute for Demographic Research and National Research University-Higher School of Economics. Findings suggest that deaths from all causes research attention in Russia increased in recent years, but the number of publications and research related engagements (e.g., networking and/ collaboration) does not match-up to other countries (e.g., UK, US, Germany). This research lag calls for more collaborative research between public health disciplines and networking among researchers (i.e., both national and international).
ARTICLE | doi:10.20944/preprints202301.0204.v2
Subject: Medicine & Pharmacology, Other Keywords: Covid-19 vaccination; death rate; sick status days
Online: 26 January 2023 (03:53:33 CET)
Background The main reason for the worldwide massive covid vaccination in 2021 was to reduce the high mortality caused by the Covid-19 virus in 2020. It is time that in 2022 a rigorous analysis is done of the effectiveness of this massive vaccination. Methods In statistics, we have an accurate methodology to measure the impact of massive vaccination on public health. The mathematical relation between vaccinated/alive groups will be repeated between vaccinated/dead groups with high statistical certainty. This occurs because we are dealing with big numbers. Results Calculations were done for five periods of four weeks: weeks 35-38 (2021), weeks 39-42 (2021), weeks 43-46 (2031), weeks 47-50 (2021), and weeks 51(2021)-2(2022). Obtained results are confirming that the mortality of the vaccinated infected groups is higher on average by 14.5% than the mortality of non-vaccinated infected groups. Conclusions Results are suggesting the extension of the statistic between the vaccinated/alive group and the vaccinated/dead group for different age groups. These statistics will have higher statistical significance because of the elimination of the Simpson effect. Calculating the exact impact of covid-19 vaccination on the mortality rate is the necessary step to satisfy the first principle of medicine: “Primum non nocere”.
ARTICLE | doi:10.20944/preprints202301.0370.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Chinese chestnut; replaceable bud; programmed cell death; transcriptomics
Online: 20 January 2023 (06:31:11 CET)
Previous research suggests that the senescence and death of the replaceable bud in chestnut cultivar (cv.) ‘Tima Zhenzhu’ involves programmed cell death (PCD). However, the molecular network responsible for regulating replaceable bud PCD is poorly characterized. Here, we performed transcriptomic profiling of the chestnut cv. ‘Tima Zhenzhu’ replaceable bud before (S20), during (S25), and after PCD (S30) to ascertain the molecular mechanism underlying the PCD process. A total of 5,779, 9,867, and 2,674 differentially expressed genes (DEGs) were discovered upon comparison of S20 vs. S25, S20 vs. S30, and S25 vs. S30, respectively. Approximately 6,137 DEGs common to at least two comparisons were selected for GO and KEGG enrichment analyses to interrogate the main corresponding biological functions and pathways. GO analysis showed that these common DEGs could be divided into three functional categories, including 15 cellular components, 14 molecular functions, and 19 biological processes. KEGG analysis found that “plant hormone signal transduction” included 93 DEGs. Overall, 441 DEGs were identified as related to the process of PCD. Most of these were found to be genes associated with ethylene signaling, as well as initiation and execution of various PCD processes. A hypothetical model, consisting of three overlapping processes, is proposed for the replaceable bud PCD: First, ethylene signaling is activated during preparation for PCD, in order to regulate the activity of downstream targets. Next, during PCD initiation, the up-regulation of several TFs (including MYB, MADS-box, bHLH, and NAC TFs) induces an increase in cytochrome c expression and in the cytosolic Ca2+ content, activating the Ca2+-dependent signaling cascade. Finally, during PCD execution, the process of autophagy and the activity of proteases (i.e., cysteine proteinases RD21A-like, metacaspase-9-like, vacuolar-processing enzyme-like, and senescence-associated proteins for hydrolysis) work synergistically to clear the cell of cellular components. When this process is complete, the replaceable bud senesces and dies.
ARTICLE | doi:10.20944/preprints202210.0145.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: oxidative stress; Xenopus laevis; eggs; overactivation; cell death
Online: 11 October 2022 (07:08:01 CEST)
Excessive activation of frog eggs (overactivation) is a pathological process that renders eggs unfertilizable. Its physiological inducers are unknown. Previously, oxidative stress was shown to cause time- and dose-dependent overactivation of Xenopus laevis frog eggs . Here, we demonstrate that the oxidative stress-induced egg overactivation is a calcium-dependent phe-nomenon which can be attenuated in the presence of the selective calcium chelator BAPTA. Degradation of cyclin B2, which is known to be initiated by calcium transient in fertilized or parthenogenetically activated eggs, can also be observed in the overactivated eggs. Decline in mitochondrial membrane potential, ATP depletion and termination of protein synthesis manifest in the eggs within one hour of triggering overactivation. These intracellular events occur in the absence of caspase activation. Furthermore, plasma membrane integrity is compromised in the overactivated eggs, as evidenced by ATP leakage and egg swelling. In sum, our data demonstrate that oxidative stress-induced overactivation of frog eggs causes fast and dramatic disruption of cellular homeostasis, resulting in robust and expedited cell death by a calcium-dependent non-apoptotic mechanism.
Subject: Medicine & Pharmacology, Allergology Keywords: fire-related death; viability; light microscopy; bronchiolar epithelium
Online: 25 February 2021 (13:12:51 CET)
Fire-related deaths are issues for forensic pathologists particularly in ascertaining if death occurred before or during fire. The authors highlight a unique bronchiolar epithelial cytological clue (nuclear heat-induced elongation) determined by active inhalation of hot gases and fumes, not yet described in the literature at distal small airways level.
REVIEW | doi:10.20944/preprints202009.0084.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: programmed cell death; inflammation; intestinal disease; cancer; inhibitors
Online: 4 September 2020 (07:21:17 CEST)
Necroptosis is a caspases-independent form of programmed cell death exhibiting intermediate features between necrosis and apoptosis. Albeit some physiological roles during embryonic development, tissue homeostasis and innate immune response are documented, necroptosis is mainly considered a pro-inflammatory cell death. Key actors of necroptosis are the receptor-interacting-protein-kinases, RIPK1 and RIPK3, and their target, the mixed-lineage-kinase-domain-like protein, MLKL. The intestinal epithelium has one of the highest rates of cellular turnover in a process that is tightly regulated. Altered necroptosis at the intestinal epithelium leads to uncontrolled microbial translocation and deleterious inflammation. Indeed, necroptosis has been associated to chronic inflammatory diseases and cancer. Drugs that inhibit necroptosis could, therefore, be used therapeutically for the treatment of these diseases, and researches to develop such inhibitors are already underway. In this Review, we outline pathways for necroptosis and its role in chronic inflammation and cancer. We also discuss current and developing therapies that target necroptosis machinery.
ARTICLE | doi:10.20944/preprints201910.0292.v1
Subject: Medicine & Pharmacology, Nursing & Health Studies Keywords: maternal death; marginalized community; flood; natural disaster; Bangladesh
Online: 27 October 2019 (03:23:48 CET)
The study explored the community perception of maternal deaths influenced by natural disaster, practice of maternal complications during natural disaster among the rural population in Bangladesh. It also explored the challenges faced by the community for providing health care and referring the complicated pregnant mothers during disaster. Three focus group discussions (FGDs) and eight in-depth interviews (IDIs) were conducted in the marginalized rural communities in the flood-prone Khaliajhuri sub-district, Netrakona district, Bangladesh. Flood is one of the major risk factors for influencing maternal death. Pregnant mothers seriously suffer from maternal complication, lack of antenatal checkup and even any doctor during flood. During the time of delivery, it is difficult to find even a skilled attendant and referring the patient with delivery complications to the healthcare facility. Boat is the only mode of transport. Majority maternal deaths occur on the boats during transfer from the community to the hospital. The rural people feel that the maternal deaths influenced by natural disaster are the natural phenomena. It needs some pre-preparation to support pregnant women during the disaster. There is unawareness of maternal health, related care and complications during disaster among the local health service providers and volunteers.
ARTICLE | doi:10.20944/preprints201811.0170.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: CKD, ESKD, Death, anti-RAS, hyperkalemia, competing risk
Online: 7 November 2018 (14:48:30 CET)
Hyperkalemia burden in non-dialysis CKD under nephrology care is undefined. We prospectively followed 2443 patients with two visits (referral and control with 12-month interval) in 46 nephrology clinics. Patients were stratified in four categories of hyperkalemia (sK≥5.0 mEq/L) by sK at visit 1 and 2: Absent (no-no), Resolving (yes-no), New Onset (no-yes), Persistent (yes-yes). We assessed competing risks of ESKD and death after visit 2. Age was 65±15 y, eGFR 35±17 mL/min/1.73 m2, proteinuria 0.40 (0.14-1.21) g/24h. In the two visits sK was 4.8±0.6 and levels ≥6 mEq/L were observed in 4%. Hyperkalemia was absent in 46%, resolving 17%, new onset 15% and persistent 22%. Renin-angiotensin-system inhibitors (RASI) were prescribed in 79% patients. During 3.6-year follow-up, 567 patients reached ESKD and 349 died. Multivariable competing risk analysis [sub-hazard ratio-sHR, 95%Confidence Interval-CI] evidenced that new onset [sHR 1.34, 95%CI 1.05-1.72] and persistent [sHR 1.27, 95%CI 1.02-1.58] hyperkalemia predicted higher ESKD risk versus absent, independently from main determinants of outcome including eGFR change. Conversely, no effect on mortality was observed. Results were confirmed by testing sK as continuous variable. Therefore, in CKD under nephrology care, mild-to-moderate hyperkalemia status is common (37%) and predicts per se higher ESKD risk but not mortality.
REVIEW | doi:10.20944/preprints201706.0121.v1
Subject: Life Sciences, Immunology Keywords: autophagy； immune system； cancer；cell death；metabolic homeostasis
Online: 27 June 2017 (06:30:17 CEST)
Autophagy is a highly conserved catabolic mechanism that mediates the degradation of damaged cellular components by inducing their fusion with lysosomes. This process provides cells with an alternative source of energy for the synthesis of new proteins and the maintenance of metabolic homeostasis in stressful environments. Numerous studies have demonstrated beneficial roles for the induction as well as the suppression of autophagy in cancer cells. Autophagy may induce either survival or death depending on the cell/tissue type. Radiation therapy is widely used therapeutic option to treat cancer, and it induces autophagy in human cancer cell line. Also, melatonin seems to affect cancer cell death via regulation of programmed cell death. In this review, we summarize the current understanding of autophagy and its regulation in cancer.
ARTICLE | doi:10.20944/preprints202205.0407.v1
Subject: Biology, Plant Sciences Keywords: Fusarium; tomato; novel effector candidates; cell death; Nicotiana benthamiana
Online: 31 May 2022 (03:20:05 CEST)
Fusarium oxysporum f. sp. lycopersici (Fol) causes vascular wilt disease in tomato. Upon colonization of the host, Fol secretes many small effector proteins into the xylem sap to facilitate infection. Besides known SIX (Secreted In Xylem) proteins, the identity of additional effectors that contribute to Fol pathogenicity remains largely unexplored. We have performed a deep RNA-sequencing analysis of Fol race 2-infected tomato, used the sequence data to annotate a published genome assembly generated via PacBio SMRT sequencing of the Fol race 2 reference strain Fol4287, and analysed the resulting transcriptome to identify Fol effector candidates among the newly annotated genes. We examined the Fol-infection expression profiles of all 13 SIX genes present in Fol race 2 and identified 27 new candidate effector genes that were likewise significantly upregulated upon Fol infection. Using Agrobacterium-mediated transformation, we tested the ability of 22 of the new candidate effector genes to suppress or induce cell death in leaves of Nicotiana benthamiana. One effector candidate designated Fol-EC19, encoding a secreted guanyl-specific ribonuclease, was found to trigger cell death and two effector candidates designated Fol-EC14 and Fol-EC20, encoding a glucanase and a secreted trypsin, respectively, were identified that can suppress Bax-mediated cell death. Remarkably, Fol-EC14 and Fol-EC20 were also found to suppress I-2/Avr2- and I/Avr1-mediated cell death. Using the yeast secretion-trap screening system, we showed that these three biologically-active effector candidates each contain a functional signal peptide for protein secretion. Our findings provide a basis for further understanding the virulence functions of Fol effectors.
ARTICLE | doi:10.20944/preprints202108.0524.v1
Subject: Social Sciences, Law Keywords: death penalty; legal system; risk; citizens; predictive model; Serbia
Online: 27 August 2021 (13:59:11 CEST)
This paper presents the results of quantitative research regarding the predictive model of citizens' attitudes about the risks of introducing the death penalty in the Republic of Serbia legal system. The research was conducted with the use of a questionnaire that was requested and then collected online from 427 people in June 2021. A multivariate regression analysis was used, identifying the extent to total scores of the main dependent variables (introducing the death penalty; trust in the legal system; advantages of introduction; disadvantages of introduction scores) were associated with five demographic and socio-economic variables: gender, marital, education, income, and age. We tested the central hypothesis of which gender is predicting variables citizens' attitudes about the risks of introducing the death penalty in the legal system of Serbia. The findings revealed that gender and educational level were the most effective predictors of the research variables under question. The majority of respondents support the introduction of the death penalty and the most important predictor of disadvantages of introducing the death penalty in the legal system is age. Based on the findings that there are major differences in the citizens' attitudes about the risks of introducing the death penalty in the legal system, policies, strategies, and regulations must take into account these very important findings.
ARTICLE | doi:10.20944/preprints202103.0685.v1
Subject: Arts & Humanities, Anthropology & Ethnography Keywords: death; grief; Internet; photograph; comparative study; social network sites
Online: 29 March 2021 (11:34:58 CEST)
Abstract: As innovative way to express grief, social media posts about the deceased have become fairly common. However, few studies examined grief photos commonly posted. The purpose of the present study was to examine such pictures, as well as the motivation and reactions of those who posted, among Italians and Americans. Surveys were sent to both Italian and U.S. participants. The U.S. group yielded 262 responses (Mean age = 22 years; 81% female), the Italian yielded 51 (Mean age = 32. Several key issues emerged, such as the need to receive empathic support from other users, the desire to maintain continuing bonds, the wish to remember the deceased, and the desire to share beauty and symbolic pictures. The images were analyzed using content analysis. Both samples posted photos to remember and to enhance their posts. A strong preference for pictures with a positive emotional connotation appeared, depicting the deceased in a conjoint appearance with the participant. Results suggest that imagery used for the expression of grief in social media sites, an “iconography of grief,” is a popular means of expression for grievers.
ARTICLE | doi:10.20944/preprints202011.0240.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Post-mortem Cardiac magnetic resonance; hypertrophic cardiomyopathy; sudden death
Online: 6 November 2020 (10:44:52 CET)
Post-mortem cardiac magnetic resonance (PMCMR) is an emerging tool supporting forensic medicine for the identification of the causes of cardiac death, as hypertrophic cardiomyopathy (HCM). We proposed a new method of PMCMR to diagnose HCM despite myocardial rigor mortis. Methods: we performed CMR in 49 HCM patients, 30 non-HCM hypertrophy and 32 healthy controls. In cine images, rigor mortis was simulated by the analysis of the cardiac phase corresponding to the 25% of diastole. Left ventricular mass, mean and standard deviation (SD) of WT, maximal WT, minimal WT and their difference, were compared for the identification of HCM. These parameters were validated at PMCMR, evaluating 8 hearts with HCM, 10 with coronary artery disease and 10 with non-cardiac death. Results: The SD of WT with a cut-off of > 2.4 had the highest accuracy to identify HCM (AUC 0.95, 95%CI 0.89-0.98). This was particularly evident in female population of HCM (AUC=0.998), with 100% specificity (95%CI 85-100%) and 96% sensitivity (95%CI 79-99%). Using this parameter, at PMCMR all the 8 patients with HCM were correctly identified with no false positive. Conclusions: PMCMR allows to identify HCM as cause of sudden death using the SD of WT >2.4 as diagnostic parameter.
Subject: Biology, Other Keywords: adaptive death; ageing; altruism; C. elegans; kin selection; salmon
Online: 4 August 2020 (11:26:31 CEST)
Standard evolutionary theory, supported by mathematical modelling of outbred, dispersed populations predicts that ageing is not an adaptation. We recently argued that in clonal, viscous populations, programmed organismal death could promote fitness through social benefits and has, in some organisms (e.g. Caenorhabditis elegans), evolved to shorten lifespan. Here we review previous adaptive death theory, including consumer sacrifice, biomass sacrifice, and defensive sacrifice types of altruistic adaptive death. In addition we discuss possible adaptive death in semelparous fish, coevolution of reproductive and adaptive death, and adaptive reproductive senescence in C. elegans. We also describe findings from recent tests for the existence of adaptive death in C. elegans using computer modelling. Such models have provided new insights into how trade-offs between fitness at the individual and colony levels mean that senescent changes can be selected traits. Exploring further the relationship between adaptive death and social interactions, we consider examples where adaptive death results more from action of kin than from self-destructive mechanisms and, to describe this, introduce the term adaptive killing of kin.
REVIEW | doi:10.20944/preprints201811.0543.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: hydroxyurea; cerebellum; neuron; immunohistochemistry; electron microscopy; cell death; apoptosis
Online: 22 November 2018 (07:09:28 CET)
The cytostatic agent hydroxyurea (HU) has proven to be beneficial for a variety of conditions in the disciplines of oncology, hematology, infectious disease and dermatology. It disrupts the S-phase of the cell cycle by inhibiting the ribonucleotide reductase enzyme, thus blocking the transformation of ribonucleotides into deoxyribonucleotides, a rate limiting step in DNA synthesis. HU is listed as an essential medicine by the World Health Organization. Several studies have indicated that HU is well tolerated and safe in pregnant women and very young pediatric patients. To our knowledge, only a few controlled studies about the adverse effects of HU therapy have been done in humans. Despite this, the prevalence of central nervous system abnormalities, including ischemic lesions and stenosis have been reported. This review will summarize and present the effects of HU-exposure on the prenatal and perinatal development of the rat cerebellar cortex and deep cerebellar nuclei neurons. Our results call for the necessity to better understand HU effects and define the administration of this drug to gestating women and young pediatric patients.
ARTICLE | doi:10.20944/preprints202001.0122.v1
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: cervical adenocarcinoma; immune-checkpoint inhibitor; programmed cell death-1(PD-1); programmed cell death-ligand 1(PD-L1); CD8 expression; lymphocyte; survival analysis
Online: 12 January 2020 (15:01:23 CET)
The effectiveness of immunotherapy for cervical adenocarcinoma (CA) has not been demonstrated yet. It may be possible for us to use programmed cell death 1 (PD-1), programmed cell death-ligand 1 (PD-L1), and CD8 as biomarkers of response to immune therapy in CA patients. In the present study, we aimed to investigate whether the expression levels of PD-1, PD-L1, and CD8 can predict the prognosis of CA patients and their response to ICI therapy. The levels of the PD-1, PD-L1, and CD8 proteins were analyzed by immunohistochemical analysis from formalin-fixed, paraffin-embedded tumor samples. The correlation between the expression levels and patient prognosis was analyzed by the Kaplan–Meier method and univariate and multivariate Cox proportional hazard regression model. We observed a significant inverse-correlation between the PD-1 and CD8 expression (p=0.001, chi square test). We also found a significant inverse-correlation between the PD-L1 and CD8 expression (p=0.027). The overall survival was significantly worse in patients with positive PD-1 expression (p=0.027). Similarly, the progression-free survival was also worse (p=0.087). Our results demonstrate that a high level of PD-1 expression is associated with a poor prognosis in CA patients. Further research is necessary to identify the molecular mechanisms that mediate this association.
ARTICLE | doi:10.20944/preprints202102.0361.v1
Subject: Life Sciences, Biochemistry Keywords: Transgenic rice; metacaspase; ER stress; salinity stress; programmed cell death
Online: 17 February 2021 (10:04:38 CET)
Endoplasmic reticulum (ER) is an important organelle responsible as protein synthesis regulator in plant. High salinity can also lead to the activation of ER stress, caused by the accumulation of misfolded protein. This could lead to a stress response mechanism, unfolded protein response (UPR). Failure of UPR to reverse the effect of protein misfolding will activate Programmed Cell Death (PCD). Metacaspase genes regulate programmed cell death (PCD) in plants. The present study was focused on comprehensive gene analyses of the expression patterns of type II rice metacaspase (OsMC) genes in response to the endoplasmic reticulum (ER) and salinity stress in rice leaf and OsMC4 in callus. A strong evidence of unfolded protein response (UPR) during tolerance to both ER and salinity stress was found in the present study. Overexpression of OsMC4 in rice callus as a fusion protein with TagRFP and controlled by the CaMV35 promoter caused major changes in the expression of the stress ER-marker genes, protein disulfide isomerase (PDI) and Binding immunoglobulin Protein (BiP), and OsMC4 in overexpressing calli. These expression analyses of the OsMC family provide valuable information for further functional studies on the biological roles of OsMCs in PCD related to ER and salinity stress responses.
REVIEW | doi:10.20944/preprints202010.0084.v2
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: adenovirus; oncolytic; virotherapy; targeting; immunotherapy; immunogenic cell death; αvβ6 integrin
Online: 3 November 2020 (08:19:31 CET)
More people are surviving longer with cancer. Whilst this can be partially attributed to advances in early detection of cancers, there is little doubt that the improvement in survival statistics is also due to the expansion in the spectrum of treatments available for efficacious treatment. Transformative amongst those are immunotherapies, which have proven effective agents for treating immunogenic forms of cancer, though immunologically “cold” tumour types remain refractive. Oncolytic viruses, such as those based on adenovirus have great potential as anti-cancer agents and have seen a resurgence of interest in recent years. Amongst their many advantages is their ability to induce immunogenic cell death (ICD) of infected tumour cells, thus providing the alluring potential to synergize with immunotherapies by turning immunologically “cold” tumours “hot”. Additionally, enhanced immune mediated cell killing can be promoted through the local overexpression of immunological transgenes, encoded from within the engineered viral genome. To achieve this full potential requires the development of refined, tumour selective “precision virotherapies” that are extensively engineered to prevent off-target up take via native routes of infection, and targeted to infect and replicate uniquely within malignantly transformed cells. Here, we review the latest advances towards this holy grail within the adenoviral field.
REVIEW | doi:10.20944/preprints202011.0019.v1
Subject: Biology, Anatomy & Morphology Keywords: aging; biomass conversion; C. elegans; reproductive death; semelparity; senescent pathology
Online: 2 November 2020 (10:45:56 CET)
In some species of salmon, reproductive maturity triggers the development of massive pathology resulting from reproductive effort, leading to rapid post-reproductive death. Such reproductive death, which occurs in many semelparous organisms (with a single bout of reproduction), can be prevented by blocking reproductive maturation, and this can increase lifespan dramatically. Reproductive death is often viewed as distinct from senescence in iteroparous organisms (with multiple bouts of reproduction) such as humans. Here we review the evidence that reproductive death occurs in C. elegans and discuss what this means for its use as a model organism to study aging. Inhibiting insulin/IGF-1 signaling and germline removal suppresses reproductive death and greatly extends lifespan in C. elegans, but can also extend lifespan to a small extent in iteroparous organisms. We argue that mechanisms of senescence operative in reproductive death exist in a less catastrophic form in iteroparous organisms, particularly those involving costly resource reallocation, and exhibiting endocrine-regulated plasticity. Thus, mechanisms of senescence in semelparous organisms (including plants) and iteroparous ones form an etiological continuum. Therefore understanding mechanisms of reproductive death in C. elegans can teach us about some mechanisms of senescence that are operative in iteroparous organisms.
HYPOTHESIS | doi:10.20944/preprints202006.0038.v1
Subject: Keywords: T-lymphocytes; programmed cell death protein-1; mitochondria; adenosine triphosphate
Online: 4 June 2020 (13:54:40 CEST)
It has been demonstrated that a decrease in cellular adenosine triphosphate (c-ATP) causes cellular dysfunction. T-cells are not an exception. One of their roles is to properly detect and eliminate cancer cells. These processes occur at the expense of ATP. Therefore, it can be concluded that a decrease in c-ATP can defect T-cell function and promote cancer evolution. In this article, we provide a hypothesis to describe the correlation between the expression of PD-1 protein on T-cells and their c-ATP levels. Moreover, we present the possible predictive factors of Anti–PD(L)-1 therapy which has not yet been determined definitely.
Subject: Life Sciences, Virology Keywords: ACE2; Spike protein; SARS-CoV2; death rate; polymorphism; isoform variant; CD157, sankramikogenomics
Online: 17 May 2020 (14:51:39 CEST)
The 2019-Novel Coronavirus has currently gripped the world in terror, affecting 210 countries and territories. Originating from Wuhan, Hubei province, China, the virus has spread so rapidly throughout the world and has already claimed 308,927 lives and is currently afflicting 4.6 million people. The US has over 1.48 million confirmed cases of COVID-19, followed by Spain, Italy, France, UK, Germany, Turkey, Russia, Iran, and China. On careful inspection of the COVID-19 statistics, a peculiar unsettling trend becomes apparent. Western European countries and the US appear to have difficulties in overcoming the catastrophe. In contrast, countries in East Asia, Middle East and mid-Europe have sorted out the situation. Here, we will highlight this trend and propose the importance of infection-genomics (sankramikogenomics), in understanding the susceptibility to COVID-19 and the severity of disease progress. More detailed, systematic evaluation may also identify more susceptible populations. We will also highlight mere 12-fold lower affinity is insufficient to ignore CD147, as interactions occur between tens of spike proteins and equal number of cell surface ACE2 and/or CD147. Thus, both receptors are important to understand sankramikogenomics and severity of COVID-19. The observed ethnic differences in COVID severities may be due to variations in structure or tissue-specific expression (alternate splicing and accessibility) of both the target receptors. Research on both receptors may help in designing improved therapeutic strategies to fight COVID-19. Similar to pharmacogenomics to drug development and precision medicine, Sankramikogenomics will become an important field in other infectious diseases and pathogenicity.
ARTICLE | doi:10.20944/preprints201908.0064.v1
Subject: Mathematics & Computer Science, Probability And Statistics Keywords: birth; death; trends; generalized linear models (GLMs); poisson; negative binomial
Online: 5 August 2019 (14:36:49 CEST)
This study investigated the trends of registered Death and Birth in Nigeria using Generalized Linear Models. Annual data on Death and Birth was collected from National Population Commission for the period of 2004 to 2017. The Natural increase calculated revealed a positive trend in the natural increase in Nigeria from 2004 to 2017. Evidence from summary statistics revealed some level of over dispersion (variance > mean). This study explored Poisson Regression Models and Negative Binomial Regression Models using two links (identity and log). The results revealed a positive increase in registration of birth and death rates in Nigeria and among the competing the models, Negative Binomial regression model with identity link emerged as the best model for modeling birth and death rates registration in Nigeria. Data on numbers of deaths and causes of death are essential if countries are to determine priorities, formulate and monitor policies for public health care as well as other government policies that may be based on such data
ARTICLE | doi:10.20944/preprints201810.0121.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: SAHA; RG7388; MDM2; p53; p21; cell cycle arrest; cell death
Online: 7 October 2018 (11:33:18 CEST)
Alterations in gene expressions are often due to epigenetic modifications that can lead to significant influence on cancer development, growth, and progression. The main epigenetic modifications observed in human are methylation and acetylation. In this regard, the HDAC inhibitors (HDACi) such as SAHA (Vorinostat), which can exert epigenetic alterations through impacting the acetylation status of histones, are in clinical trials as a new class of drugs with promising effects on the cancer growth and metastatic process. The small molecule RG7388 is a newly developed inhibitor that is specific for an oncogene-derived protein called MDM2, which is in clinical trials for the treatment of various types of cancers. One of the common characteristics for these two drugs is their ability to induce p21 expression through distinct mechanisms in MCF-7 and LNCaP cells. This difference was expected trigger cell cycle arrest and cell death through intra-cellular mechanisms that are not identical. Hence, the molecular mechanism whereby SAHA can induce cell cycle arrest and trigger necrosis, apoptosis or necroptosis is still evolving. Similarly, the ability of RG7388 for producing anticancer effect is undergoing thorough investigation, since it can produce p53 dependent and p53 independent effects. In this study we performed experiments to measure the cell cycle arrest effects of SAHA and RG7388 on using MCF-7 and LNCaP cells. The cytotoxicity, cell cycle arrest and apoptosis/necroptosis effects of the treatments were assessed by using Trypan Blue Dye Exclusion (TBDE) method, MTT assay, Fluorescence assay with DEVD-amc fluorogenic substrate and Immunoblotting methods. Our results from MCF-7 and LNCaP cells confirmed that SAHA and RG7388 treatments were able to induce cell death via combination of cell cycle arrest and cytotoxic mechanisms. We are speculating that our findings could lead to the development of newer treatments for breast and prostate cancers using this type of combinations.
ARTICLE | doi:10.20944/preprints201805.0183.v1
Subject: Arts & Humanities, General Humanities Keywords: death; bodies; human rights; burial; ethics; tourism; heritage; culture; memory
Online: 14 May 2018 (05:32:40 CEST)
In The Work of the Dead: A Cultural History of Mortal Remains, Thomas Laqueur argues that the work of the dead is carried out through the living and through those who remember, honour, and mourn the dead. Further, he maintains that the brutal or careless disposal of the corpse “is an attack of extreme violence”. To treat the dead body as if it does not matter or as if it were ordinary organic matter would be to deny its humanity. From Laqueur’s point of view it is inferred that the dead are believed to have rights and dignities that are upheld through rituals, practices, and beliefs of the living. Drawing on dark tourism scholarship and cultural memory theory, this paper examines the display of human bones at Sedlec Ossuary, Czech Republic and the tourist culture that has built up around the site. Primarily, my writing calls into question the commoditization of burial places as a conceivable violation of the human rights of the dead. My research is driven by a number of questions: What is it that draws tourists to burial grounds and how do heritage sites negotiate visitor experiences? What are the ethical boundaries when a final resting place with bodies on display is also marketed as a tourist site? Do the dead have human rights and how are the living responsible for preserving those rights?
ARTICLE | doi:10.20944/preprints202212.0020.v2
Subject: Life Sciences, Molecular Biology Keywords: spinal cord injury; apoptotic cell death; XIAP; neuroprotection; miRNA-based therapies
Online: 11 January 2023 (11:39:24 CET)
Altered expression of microRNAs (miRNAs) after spinal cord injury (SCI) has been described as being responsible for the main secondary responses, such as apoptosis. X-linked inhibitor apoptosis protein (XIAP) is a key apoptotic component involved in the progression of apoptotic programmed cell death. Several regulators have been described to modulate the XIAP's function, including the post-transcriptional regulator's miRNAs. The main aim of the present work is to identify miRNAs with altered expression after SCI which can regulate XIAP expression. Our bioinformatic analyses identified several candidate miRNAs that may regulate XIAP, among which miR-199a-5p may be involved in the downregulation of XIAP after SCI. Gene reporter assays and in vitro analyses in the neural C6 cell line confirmed the targeting of miR-199a-5p on the 3-UTR of the rat XIAP and its post-transcriptional regulation of XIAP protein level, but not at mRNA level. Analyses in a rat model of SCI revealed a trend towards increased expression of miR-199a-5p and a decrease in XIAP protein level at 3 days after injury. Finally, using a specific fluorescent in situ hybridization (FISH) probe for miR-199a-5p, we characterized the expression pattern of miR-199a-5p in cells of uninjured and rat-contused spinal cords. These findings provide new insights into apoptotic miRNA-mediated mechanisms after SCI, which will help us develop therapeutic strategies based on miRNAs for treating SCI.
ARTICLE | doi:10.20944/preprints202108.0494.v1
Subject: Life Sciences, Immunology Keywords: Glioblastoma; immunogenic cell death; innate immunity; natural Killer; macrophages; magnetic hyperthermia
Online: 25 August 2021 (13:45:34 CEST)
Cancer immunotherapies are gaining a large popularity and many of them have been approved as standard second-line or in some cases even as first-line treatment for a wide range of cancers. However, immunotherapy has not shown a clinically relevant success in glioblastoma (GBM), principally due to the brain’s “immune-privileged” status and the peculiar tumor microenvironment (TME) of GBM featured by lack of presence of tumor-infiltrating lymphocytes and the establishment of immunosuppressive mechanisms. Emerging evidence has highlighted the key role played by innate immune cells in immunosurveillance and in initiating and driving immune responses against GBM. Immunogenic cell death (ICD) is a promising approach to elicit direct activation of the innate immune system by inducing in target cancer cells the expression of molecular signatures recognized through a repertoire of innate immune cell pattern recognition receptors (PRRs) by effector innate immune cells. Herein, we explored local mild thermal treatment, generated by using ultrasmall (size ~ 17 nm) cubic-shaped iron oxide nanoparticles exposed to an external alternating magnetic field (AMF), to induce ICD in U87 glioblastoma cells. In accordance with what has been previously observed with other types of tumors, we found that mild hyperthermia modulates the immunological profile of U87 glioblastoma cells by inducing stress-associated signals leading to enhanced phagocytosis and killing of U87 cells by macrophages. Finally, we demonstrated that mild magnetic hyperthermia has a modulatory effect on the expression of inhibitory and activating NK cell ligands on target cells. Interestingly, alteration in the expression of NK ligands, caused by mild hyperthermia treatment, in U87 glioblastoma cells, increased their susceptibility to NK cell killing and NK cell functionality. The overall findings demonstrate that mild magnetic hyperthermia stimulates ICD and sensitizes GBM cells to NK-mediated killing by inducing the upregulation of specific stress ligands, providing a novel immunotherapeutic approach for GBM treatment, with potential to synergize with existing NK cell-based therapies thus improving their therapeutic outcomes.
REVIEW | doi:10.20944/preprints202105.0730.v1
Subject: Life Sciences, Biochemistry Keywords: intrauterine growth restriction (IUGR); metabolism; cell stress; cell death; metabolic syndrome
Online: 31 May 2021 (10:19:23 CEST)
Disruption of the in utero environment can have dire consequences on fetal growth and development. Intrauterine growth restriction (IUGR) is a pathological condition by which the fetus deviates from its expected growth trajectory, resulting in low birth weight and impaired organ function. The developmental origins of health and disease (DOHaD) postulates that IUGR has lifelong consequences on offspring well-being, as human studies have established an inverse relationship between birth weight and long-term metabolic health. While these trends are apparent in epidemiological data, animal studies have been essential in defining the molecular mechanisms that contribute to this relationship. One such mechanism is cellular stress, a prominent underlying cause of the metabolic syndrome. As such, this review considers the role of oxidative stress, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, and inflammation in the pathogenesis of metabolic disease in IUGR offspring. In addition, we summarize how uncontrolled cellular stress can lead to programmed cell death within the metabolic organs of IUGR offspring.
ARTICLE | doi:10.20944/preprints202009.0194.v1
Subject: Life Sciences, Molecular Biology Keywords: Oenothera biennis; Evening primrose; Oxidative stress; Cell death; Nrf2/HO-1
Online: 9 September 2020 (03:29:52 CEST)
Background: Oenothera biennis (evening primrose) produces bioactive substances with a diverse range of pharmacological functions. However, it is currently unknown whether extract prepared from the aerial parts of O. biennis (APOB) can protect the skin against oxidative stress. To investigate the protective effects of APOB against oxidative stress-induced damage in human skin keratinocytes (HaCaT) and elucidate the underlying mechanisms. Methods: We pretreated HaCaT cells with various concentrations of APOB or the antioxidant N-acetyl-L-cysteine before applying H2O2. We then compared the cell viability, intracellular reactive oxygen species (ROS) production, and DNA and mitochondrial damage between pretreated and untreated control cells using a range of assays, flow cytometry, and Western blot analysis and also examined the reducing power and DPPH free radical-scavenging activity of APOB. Results: APOB pretreatment significantly increased cell viability, effectively attenuated H2O2-induced comet tail formation, and inhibited H2O2-induced phosphorylation of the histone γH2AX, as well as the number of apoptotic bodies and Annexin V-positive cells. APOB was found to have a high reducing power and DPPH radical-scavenging activity and also exhibited scavenging activity against intracellular ROS accumulation and restored the loss of mitochondrial membrane potential caused by H2O2. APOB pretreatment almost totally reversed the enhanced cleavage of caspase-3, the degradation of poly (ADP-ribose)-polymerase (PARP), DNA fragmentation that usually occurs in the presence of H2O2 and increased the levels of heme oxygenase-1 (HO-1), a potent antioxidant enzyme that is associated with the induction of nuclear factor-erythroid 2-related factor 2 (Nrf2). Conclusions: APOB can protect HaCaT cells from H2O2-induced DNA damage and cell death by blocking cellular damage related to oxidative stress via a mechanism that affects ROS elimination and by activating the Nrf2/HO-1 signaling pathway.
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: traditional korean medicine; hippocampus; neuronal cell death; oxidative stress; medicinal herbs
Online: 10 November 2019 (14:53:14 CET)
Incident rates of neurodegenerative diseases have steadily increased globally, but there is no therapeutic access available. We newly prescribed medicinal herbal remedy including five different herbal plants called, Chen-Ma-Dan-Sam-Ga-Mi-Bang (CMST), purposed to prove for pharmacological properties and corresponded actions on hippocampus neuronal cell injury by hypoxia-induced mice model. Mice were adapted to normoxia or hypoxia with or without CMST for 5 days. We gathered pharmacological effects of CMST on cell injury by enhancement of dihydroethidium and 4-hydroxynonenal signals which were correlated with abnormal redox status in the protein or gene expression levels (abnormal elevations of nitric oxide, reactive oxygen species, lipid peroxidation and deteriorations of total glutathione, total antioxidant capacity, and activities of superoxide dismutase and catalase) due to hypoxia. CMST also notably exerted to attenuates molecules for neuronal cell injury markers such as p-tau, cleaved caspase-3 due to DNA oxidations (53bp1and phosphor-histone H2AX), inflammatory cytokines, and hemeoxigenase-1. We further figured out the underlying actions of CMST by in vitro experiment through inactivation of microglial cell which can mediate neuronal cell injury. Collectively, CMST prevented from hippocampal neuronal cells via inactivation of microglial cell with normalization of redox status on hypoxia-induced hippocampus neuronal cell injury.
ARTICLE | doi:10.20944/preprints201908.0167.v1
Subject: Life Sciences, Virology Keywords: Zika virus; programmed cell death; viral replication; Bcl-2 protein family
Online: 15 August 2019 (07:39:04 CEST)
Zika virus (ZIKV) is an emerging human mosquito-transmitted pathogen of global concern, known to cause severe complications such as congenital defects and neurological disorders in adults. ZIKV infection is associated with cell death. However, previous studies suggest that the virally-induced apoptosis occurs at a slower rate compared to the course of viral production. In this present study, we investigated the capacity of ZIKV to delay host cell apoptosis. We provide evidence that ZIKV has the ability to control programmed cell death whether it is intrinsically or extrinsically induced. In cells expressing viral replicon-type constructions, we show that this control is achieved through replication. Finally, our work highlights an important role for anti-apoptotic Bcl-2 family protein in the ability of ZIKV to control apoptotic pathways, avoiding premature cell death and thereby promoting virus replication in the host-cell.
REVIEW | doi:10.20944/preprints201811.0592.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: caspase-3; cell death; apoptosis; cell proliferation; neurons; glia; cerebellum; development
Online: 26 November 2018 (11:48:00 CET)
Caspase-3, onto which there is a convergence of the intrinsic and extrinsic apoptotic pathways, is the main executioner of apoptosis. We here review the current literature on the intervention of the protease in the execution of naturally occurring neuronal death (NOND) during cerebellar development. We will consider data on the most common altricial species (rat, mouse and rabbit), as well as humans. Among the different types of neurons and glia in cerebellum, there is ample evidence for an intervention of caspase-3 in the regulation of NOND of the post-mitotic cerebellar granule cells (CGCs) and Purkinje neurons as a consequence of failure to establish proper synaptic contacts with target (secondary cell death). It seems possible that also the GABAergic interneurons undergo a similar type of secondary cell death, but the intervention of caspase-3 in this case still remains to be clarified in full. Remarkably, CGCs also undergo primary cell death at the precursor/pre-migratory stage of differentiation, in this case without the intervention of caspase-3. Glial cells as well undergo a process of regulated cell death, but it seems possible that expression of caspase-3, at least in the Bergmann glia, is related to differentiation rather than death.
ARTICLE | doi:10.20944/preprints201810.0678.v1
Subject: Medicine & Pharmacology, Pediatrics Keywords: post-operative death; unstructured data; logistic regression; text mining; surgery outcome
Online: 29 October 2018 (11:46:18 CET)
Text fields in electronic medical records (EMR) contain information on important factors that influence health outcomes, however, they are underutilized in clinical decision making due to their unstructured nature. We analyzed 6,497 inpatient surgical cases with 719,308 free text notes from Le Bonheur Children’s Hospital EMR. We used a text mining approach on preoperative notes to obtain the text-based risk score algorithm as predictive of death within 30 days of surgery. We studied the additional performance obtained by including text-based risk score as a predictor of death along with other structured data based clinical risk factors. The C-statistic of a logistic regression model with 5-fold cross-validation significantly improved from 0.76 to 0.92 when text-based risk scores were included in addition to structured data. We conclude that preoperative free text notes in EMR include significant information that can predict adverse surgery outcomes.
ARTICLE | doi:10.20944/preprints201809.0357.v1
Subject: Life Sciences, Other Keywords: Performance, Sports, Aortic Valve, Sinus of Valsalva, Echocardiography, Sudden cardiac death
Online: 18 September 2018 (14:40:43 CEST)
Aortic rupture is known as one of the potential causes of sudden cardiac death in athletes. Nevertheless, adaptation strategies for aortic root dilation in athletes vary. The purpose of this study was to investigate aortic root adaptation to physical workload and to determine if aortic root’s and left ventricle sizes are contingent upon the physical workload. Echocardiography was applied to 151 subjects to measure the aortic root at aortic valve annulus (AA) and at sinus of Valsalva (VS). 122 were athletes (41 females and 81 males) and 29 were non-athletes (14 females and 15 males). Of the 41 female athletes, 32 were endurance athletes, and 9 strength athletes. From 81 male athletes, 56 were endurance athletes, and 25 were strength athletes. AA and VS mean values for the body surface area were presented as rAA and rVS. Left ventricle (LV) meaures incuded LV end-diastolic diameter (LVEDD), interventricular septum thickness in diastole (IVSTd), LV posterior wall thickness in diastole (LVPWTd), LV mass (LVM), LV mass index, LV end-diastolic diameter index (LVEDDI). Results indicated that VS was higher in female athletes (28.9±2.36mm) than in non-athletes (27.19±2.87mm, p=0.03). On the other hand, rAA was higher in strength athletes (12.19±1.48mm/m2) than in endurance athletes (11.12±0.99mm/m2, p=0.04). Additionally, rVS and rAA were higher in female strength athletes (17.19±1.78mm/m2, 12.19±1.48mm/m2) than female basketball players (15.49±1.08mm/m2, p=0.03, 10.75±1.06 mm/m2, p=0.02). Statistically significant positive moderate correlations were found between VS and LVEDD, LVM, IVSTd, LVPWTd, rVS and LVEDDI parameters in all athletes. The diameter of Valsalva sinus was greater in female athletes compared to non-athletes. The rAA mean value for body surface area was greater in female athletes practising strength sports as compared to their counterparts who were practising endurance sports. The diameter of the aortic root at sinuses positively correlated with the LV size in all athletes. Trial was registered at ClinicalTrials.gov Identifier: NCT03656861, September 3, 2018 (retrospectively registered).
ARTICLE | doi:10.20944/preprints201703.0162.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Particulate matter; BM-MSCs; cell proliferation; cell death; qRT-PCR; IPA
Online: 20 March 2017 (16:33:56 CET)
Particulate matter (PM) contains heavy metals that affect various cellular functions and gene expression associated with an array of acute and chronic diseases, in humans. However, their specific effects on the stem cells remain unclear. Here, we report the effects of PM collected from Jeddah city on bone marrow mesenchymal stem cells (BM-MSCs) on proliferation, cell death, related gene expression and systems biological analysis aiming to understand the underlying mechanisms. Two different sizes (PM2.5-10) were tested in vitro at various concentrations (15 to 300 µg/ml) and durations (24 to 72 h). PMs induced cellular stress including membrane damage, shrinkage and death. Lower concentrations of PM2.5 increased BM-MSCs proliferation, while higher concentrations decreased it. PM10 decreased BM-MSCs proliferation in a concentration-dependant manner. The X-Ray Fluorescence spectrometric analysis showed that PM contains high levels of heavy metals. Ingenuity Pathway Analysis (IPA) and hierarchical clustering analyses showed that heavy metals were associated with signalling pathways involving cell stress/death, cancer and chronic diseases. qRT-PCR results showed differential regulation of the apoptosis genes (BCL2, BAX); upregulation of inflammation associated genes (TNF-a and IL-6) and downregulation of cell cycle regulation gene (P53). We conclude that PM could affect different cellular functions and predispose to debilitating diseases.
ARTICLE | doi:10.20944/preprints202208.0369.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: MTH1; TH588; TH1579; c-Myc; replication stress; DNA damage; cell death; cancer
Online: 22 August 2022 (03:37:41 CEST)
Previously, we reported that MTH1 inhibitors TH588 and TH1579 selectively induce oxidative damage and kill Ras expressing or transforming cancer cells, as compared to non-transforming immortalized or primary cells. While this explains the impressive anti-cancer properties of the compounds, the molecular mechanism remains elusive. Oncogenes induce replication stress, re-sulting in under replicated DNA and replication continuing into mitosis, where TH588 and TH1579 treatment cause toxicity and incorporation of oxidative damage. Hence, we hypothesized that oncogene-induced replication stress explains the cancer selectivity. To test this, we overex-pressed c-Myc in human epithelial kidney cells (HA1EB), resulting in increased proliferation, polyploidy and replication stress. TH588 and TH1579 selectively kill c-Myc overexpressing clones, enforcing the cancer cell selective killing of these compounds. Moreover, the toxicity of TH588 and TH1579 in c-Myc overexpressing cells is rescued by transcription, proteasome or CDK1 inhibitors, but interestingly not by nucleoside supplementation. This suggest that cancer selectivity is unrelated oncogene-induced replication stress. We conclude that the molecular toxi-cological mechanisms how TH588 and TH1579 kill c-Myc overexpressing cells have several com-ponents and involves MTH1-independent proteosomal degradation of c-Myc itself, c-Myc driven transcription and CDK activation, and is likely unrelated to oncogene-induced replication stress.
ARTICLE | doi:10.20944/preprints202204.0053.v1
Subject: Life Sciences, Other Keywords: Programmed death ligand-1; Natural products; Immunotherapy; Neoenactin B1; Molecular dynamics simulation
Online: 7 April 2022 (04:08:19 CEST)
Several therapeutic monoclonal antibodies are approved by FDA against the PD-1/PD-L1 (programmed death-1/programmed death ligand-1) immune checkpoint, which has been a great success in cancer treatment. However, existing therapeutics, including small molecules inhibitors against PD-L1 checkpoint have certain drawbacks such as high cost and drug resistance that challenge the current available anti-PD-L1 therapy. Thereof, this study presents the screening of 32552 compounds from Natural Product Atlas database against PD-L1, including three steps of structure-based virtual screening and binding free energy refinement for the selection of potent PD-L1 inhibitors. Subsequently, five natural compounds, i.e., Neoenactin B1, Actinofuranone I, Cosmosporin, Ganocapenoid A, and 3-[3-hydroxy-4-(3-methylbut-2-enyl)phenyl]-5-(4-hydroxybenzyl)-4-methyldihydrofuran-2(3H)-one, were collected based on the ADMET (absorption, distribution, metabolism, excretion, and toxicity) profiling and binding free energy (>-70 kcal/mol) for further computational investigation by comparison to co-crystallised ligand, i.e. JQT inhibitor. Based on interaction mapping, explicit 100 ns molecular dynamics simulation, and post binding free energy calculations, all the compounds exhibited intermolecular interactions (hydrogen and hydrophobic) with essential residues and substantial complex stability by comparison to the JQT inhibitor. Collectively, the calculated results advocate the selected natural compounds as the putative potent inhibitors of PD-L1 and, therefore, can be considered for further development of PD-L1 immune checkpoint inhibitor in cancer immunotherapy.
REVIEW | doi:10.20944/preprints202104.0751.v1
Subject: Life Sciences, Biochemistry Keywords: efferocytosis; cell death; apoptosis; intracellular trafficking; transcriptional regulation; cellular metabolism; inflammation; resolution
Online: 28 April 2021 (15:28:24 CEST)
Apoptosis, the programmed and intentional death of senescent, damaged, or otherwise superfluous cells, is the natural end-point for most cells within multicellular organisms. Apoptotic cells are not inherently damaging, but if left unattended they can lyse through secondary necrosis. The resulting release of intracellular contents drives inflammation in the surrounding tissue and can lead to autoimmunity. These negative consequences of secondary necrosis are avoided by efferocytosis—the phagocytic clearance of apoptotic cells. Efferocytosis is a product of both apoptotic cell and efferocyte mechanisms, which cooperate to ensure the rapid and complete removal of apoptotic cells. Herein, the processes used by apoptotic cells to ensure their timely removal, and the receptors, signaling, and cellular processes used by efferocytes to identify, remove, and process the apoptotic cells, are reviewed.
ARTICLE | doi:10.20944/preprints202103.0019.v1
Online: 1 March 2021 (13:46:57 CET)
The coronavirus disease pandemic 2019 (COVID-19) has emerged in Wuhan province, China in December 2019 and has spread over all countries. The current study was carried out to predict active, death and cured rate of COVID 19 in Algeria for a future period of 35 days using FB prophet model. Results shoed that the active rate and the death rate decrease for the next days while the cured rate increase. The active, cured and death rates are estimated at 19.7% 78.85% and 2.55% respectively. These results highlight the importance of FB prophet model in COVID-19 prediction which could help national authorities in adopting the best preventive measures.
ARTICLE | doi:10.20944/preprints201703.0237.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: valproic acid; doxorubicin; reactive oxygen species; autophagy; cell death; caveolae endocytosis pathway
Online: 31 March 2017 (12:08:53 CEST)
We evaluated the mono- and combination-therapy effects of valproic acid (VPA) and doxorubicin (DOX) in hepatocellular carcinoma (HCC) and identified a specific and efficient, synergistic anti-proliferative effect of the VPA and DOX combination in HCC cells, especially HepG2 cells; this effect was not apparent in MIHA cells, a normal hepatocyte cell line. The calculation of the coefficient of drug interaction confirmed the significant synergistic effect of the combination treatment. Concurrently, the synergistic apoptotic cell death caused by the VPA and DOX combination treatment was confirmed by Hoechst nuclear staining and western blot analysis of caspase-3 and poly (ADP-ribose) polymerase (PARP) activation. Co-treatment with VPA and DOX enhanced reactive oxygen species (ROS) generation and autophagy, which were clearly attenuated by ROS and autophagy inhibitors, respectively. Furthermore, as an indication of the mechanism underlying the synergistic effect, we observed that DOX internalization, which was induced in the VPA and DOX combination-treated group, occurred via by the caveolae-mediated endocytosis pathway. Taken together, our study uncovered the potential effect of the VPA and DOX combination treatment with regard to cell death, including induction of cellular ROS, autophagy, and the caveolae-mediated endocytosis pathway. Therefore, these results present novel implications in drug delivery research for the treatment of HCC.
ARTICLE | doi:10.20944/preprints202110.0039.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: zebrafish; lateral line; neuromast; hair cell; ototoxicity; toxicity; regeneration; cell death; neomycin; aminoglycosides
Online: 4 October 2021 (10:27:34 CEST)
Acute chemical ablation of lateral line hair cells is an important tool to understand lateral line-mediated behaviors in free-swimming fish larvae and adults. However, lateral line-mediated behaviors have not been described in fish larvae prior to swim bladder inflation, possibly because single doses of ototoxin do not effectively silence lateral line function at early developmental stages. To determine if ototoxins can effectively silence the lateral line during early development, we repeatedly expose zebrafish larvae to the ototoxin neomycin during a 36-hour period from 3-4 days post-fertilization (dpf). We use simultaneous transgenic and vital dye labeling of hair cells to compare 6- hour and 12-hour repeated treatment timelines and neomycin concentrations between 0–400 µM in terms of larval survival, hair cell death, regeneration, and functional recovery. Following exposure to neomycin, we find that the emergence of newly functional hair cells outpaces cellular regeneration, likely due to the maturation of ototoxin-resistant hair cells that survive treatment. Furthermore, hair cells of 4 dpf larvae exhibit faster recovery compared to 3 dpf larvae. Our data suggest that the rapid functional maturation of ototoxin-resistant hair cells limits the effectiveness of chemical-based methods to disrupt lateral line function. Furthermore, we show that repeated neomycin treatments can continually ablate lateral line hair cells between 3–4 dpf in larval zebrafish.
ARTICLE | doi:10.20944/preprints202007.0272.v1
Subject: Biology, Plant Sciences Keywords: biotic stress; plant defense response; hypersensitive response; programmed cell death; reactive oxygen species
Online: 12 July 2020 (18:50:51 CEST)
Nonhost disease resistance is the most common type of plant defense mechanism against potential pathogens. In this study, the metabolic enzyme formate dehydrogenase (FDH1) was identified to be involved in nonhost disease resistance in Nicotiana benthamiana and Arabidopsis thaliana. In Arabidopsis, AtFDH1 was highly upregulated in response to both host and nonhost bacterial pathogens. Arabidopsis Atfdh1 mutants were compromised in nonhost resistance, basal resistance, and gene-for-gene resistance. The expression patterns of salicylic acid (SA) and jasmonic acid (JA) marker genes after pathogen infections in Atfdh1 mutant indicated that SA is most likely involved in the FDH1-mediated plant defense response to both host and nonhost bacterial pathogens. Previous studies reported that FDH1 localizes to only mitochondria, or both mitochondria and chloroplasts. Our results showed that the AtFDH1 localized to mitochondria and the amount of FDH1 localized to mitochondria increased upon infection with host or nonhost pathogens. Interestingly, the subcellular localization of FDH1 was observed in both mitochondria and chloroplasts after infection with a nonhost pathogen in Arabidopsis. We speculate that FDH1 plays a role in cellular signaling networks between mitochondria and chloroplasts to produce coordinated defense responses such as SA-induced reactive oxygen species (ROS) generation and hypersensitive response (HR)-induced cell death against nonhost bacterial pathogens.
ARTICLE | doi:10.20944/preprints201805.0363.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: autophagic cell death; curcumin; human GD3 synthase (hST8Sia I); A549 cells; transcriptional regulation
Online: 25 May 2018 (11:12:02 CEST)
Curcumin, a natural polyphenolic compound isolated from the plant Curcuma longa, is known to induce autophagy in various cancer cells, including lung cancer. In the present study, we also confirmed by LC3 immunofluorescence and immunoblotting analyses that curcumin triggers autophagy in human lung adenocarcinoma A549 cell line. In parallel with autophagy induction, gene expression of human GD3 synthase (hST8Sia I) responsible for ganglioside GD3 synthesis was markedly elevated in response to curcumin in A549 cells. To investigate transcriptional activation of hST8Sia I associated with autophagy formation in curcumin-treated A549 cells, functional characterization of the 5’-flanking region of the hST8Sia I gene was carried out using luciferase reporter assay system. Deletion analysis demonstrated that the -1146 to -646 region, which includes putative c-Ets-1, CREB, AP-1 and NF-κB binding sites, functions as the curcumin-responsive promoter of hST8Sia I in A549 cells. Site-directed mutagenesis and chromatin immunoprecipitation assay demonstrated that the NF-κB binding site at -731 to -722 was indispensable for the curcumin-induced hST8Sia I gene expression in A549 cells. Moreover, the transcriptional activation of hST8Sia I by curcumin A549 cells was strongly inhibited by compound C, an inhibitor of AMP-activated protein kinase (AMPK). These results suggest that curcumin controls hST8Sia I gene expression via AMPK signal pathway in A549 cells.
ARTICLE | doi:10.20944/preprints202204.0063.v1
Subject: Chemistry, Medicinal Chemistry Keywords: S-allylcysteine; caffeic acid; hybrid compounds; in silico studies; colorectal cancer; cell death; apoptosis
Online: 7 April 2022 (14:16:48 CEST)
Conventional chemotherapy for colorectal cancer (CRC) gives only a small increase in patient survival, since it is often diagnosed in late stages, when tumor has disseminated to other organs. Besides, it is common to observe that malignant cells acquire tumor escape mechanisms which leads to therapy resistance. Considering these facts, the discovery of new molecules with therapeutic potential has become an invaluable tool in chemoprevention. In this context, we previously evaluated two hybrids (SAC-CAFA-MET and SAC-CAFA-PENT) which exhibited selective cytotoxicity against SW480, with better results than the conventional chemotherapeutic agent (5-fluorouracil; 5-FU). Here, we investigated a little deeper in the possible mechanism of these molecules to identify potential therapeutic alternatives for the treatment of CRC. Both compounds induced cell damage and reduced ROS formation. Further evaluations showed that SAC-CAFA-MET induces cell death independent from caspases and p53, but probably mediated by the negative regulation of the proapoptotic Bcl-2. In addition, the lack of activation of caspase 8 and the positive regulation of caspase 3 induced by SAC-CAFA-PENT suggest this compound acts through an apoptotic mechanism, probably initiated by intrinsic pathway. Besides, the down regulation of IL-6 by SAC-CAFA-PENT suggests it also induces a significant anti-inflammatory process. In addition, docking studies would suggest caspase-3 modulation as the primary mechanism by which hybrids elicits apoptosis in human colorectal adenocarcinoma SW480. Meanwhile, DFT calculations suggest that hybrids would produce effects in modulation of ROS in SW480 cells via hydrogen atom transfer pathway (HAT). Finally, both, SAC-CAFA-MET and SAC-CAFA-PENT displayed a favorable pharmacokinetic profile. The current work highlights the potential of the lead compounds SAC-CAFA-MET and SAC-CAFA-PENT as potential agents for colorectal cancer chemoprevention.
ARTICLE | doi:10.20944/preprints202201.0082.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: breast cancer; cancer stem cell; therapy resistance; cationic amphiphilic drug; lysosome-dependent cell death
Online: 6 January 2022 (11:51:28 CET)
The resistance of cancer cell subpopulations, including cancer stem cell (CSC) populations, to apoptosis-inducing chemotherapeutic agents is a key barrier to improved outcomes for cancer patients. The cationic amphiphilic drug hexamethylene amiloride (HMA) has been previously demonstrated to efficiently kill bulk breast cancer cells independent of tumor subtype or species, but acts poorly toward non-transformed cells derived from multiple tissues. Here we demonstrate that HMA is similarly cytotoxic toward breast CSC-related subpopulations that are resistant to conventional chemotherapeutic agents, but poorly cytotoxic toward normal mammary stem cells. HMA inhibits the sphere-forming capacity of FACS-sorted human and mouse mammary CSC-related cells in vitro, specifically kills tumor but not normal mammary organoids ex vivo, and inhibits metastatic outgrowth in vivo, consistent with CSC suppression. Moreover, HMA inhibits viability and sphere formation by lung, colon, pancreatic, brain, liver, prostate and bladder tumor cell lines, suggesting that its effects may be applicable to multiple malignancies. Mechanistically, HMA elicits the permeabilization of the limiting lysosomal membrane, a hallmark feature of the lysosome-dependent cell death pathway. Our observations expose a key vulnerability intrinsic to cancer stem cells, and point to novel strategies for the exploitation of cationic amphiphilic drugs in cancer treatment.
ARTICLE | doi:10.20944/preprints202106.0246.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: Arrhythmogenic cardiomyopathy; arrhythmogenic right ventricular cardiomyopathy; cardiac conduction system; sudden unexpected cardiac death; autopsy
Online: 9 June 2021 (08:49:09 CEST)
A retrospective study was conducted on pathologically diagnosed arrhythmogenic cardiomyopathy (ACM) from consecutive cases over the past 34 years (n = 1,109). The cardiac conduction system (CCS) was removed in two blocks, containing the following structures: Sino-atrial node (SAN), atrio-ventricular junction (AVJ) including the atrio-ventricular node (AVN), the His bundle (HB), the bifurcation (BIF), the left bundle branch (LBB) and the right bundle branch (RBB). The ACM cases (2.07% of the total cases) consisted of 20 (86.96%) sudden unexpected cardiac death (SUCD) and 3 (13.04%) native explanted hearts; 16 (69.56%) were males and 7 (30.44%) were females, ranging in age from 5 to 65 (mean age ± SD, 36.13 ± 16.06) years. The following anomalies of the CCS, displayed as percentages of ACM SUCD cases, have been detected: Hypoplasia of SAN (80%) and/or AVJ (86.67%) due to fatty-fibrous involvement, AVJ dispersion and/or septation (46.67%), central fibrous body (CFB) hypoplasia (33.33%), fibromuscular dysplasia of SAN (20%) and/or AVN (26.67%) arteries, hemorrhage and infarct-like lesions of CCS (13.33%), islands of conduction tissue in CFB (13.33%), Mahaim fibers (13.33%), LBB block by fibrosis (13.33%), AVN tongue (13.33%), HB duplicity (6.67%%), CFB cartilaginous meta-hyperplasia (6.67%), and right sided HB (6.67%). Arrhythmias are the hallmark of ACM, not only from the fatty-fibrous disruption of the ventricular myocardium that accounts for reentrant ventricular tachycardia, but also from the fatty-fibrous involvement of CCS itself. The careful examination of the cardiac conduction system on serial sections was crucial in documenting the fatty-fibrous infiltration of CCS in ACM.
ARTICLE | doi:10.20944/preprints201811.0421.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: circulating tumor cells; CTCs; breast cancer; metastasis; death receptor; TRAIL; apoptosis; in vitro model
Online: 19 November 2018 (06:44:04 CET)
Circulating tumor cells (CTCs) in the peripheral blood are the precursors to distant metastasis but the underlying mechanisms are poorly understood. This study aims at understanding the molecular features within CTCs in relation to their metastatic potential. Using in vitro CTC models, in which breast cancer cell lines are cultured in non-adherent conditions simulating the microenvironment in the blood stream, we found that suspension culture resulted in resistance to TNF-related apoptosis inducing ligand (TRAIL)-mediated cell death. Such a resistance was directly correlated with a reduction in surface and total levels of DR5 protein. In the non-adherent state, cells underwent rapid autophagic flux characterized by an accumulation of autophagosome organelles. Notably, DR5 was translocated to autophagosomes and underwent lysosomal degradation. Our data suggest that CTCs may evade TNF cytokine mediated immune surveillance through downregulation of DR expression. The data warrants further studies in cancer patients to find the status of DRs and other molecular features within primary CTCs in relation to disease progression or chemoresistance.
ARTICLE | doi:10.20944/preprints201712.0159.v1
Subject: Mathematics & Computer Science, Analysis Keywords: mathematical modeling; biological networks; sensitivity analysis; programmed cell death; single cell dynamics; cell population
Online: 22 December 2017 (01:48:00 CET)
Studies performed at single-cell resolution have demonstrated the physiological significance of cell-to-cell variability. Various types of mathematical models and systems analyses of biological networks have further been used to gain a better understanding of the sources and regulatory mechanisms of such variability. In this work, we present a novel sensitivity analysis method, called molecular density function perturbation (MDFP), for the dynamical analysis of cellular heterogeneity. The proposed analysis is based on introducing perturbations to the density or distribution function of the cellular state variables at specific time points, and quantifying how such perturbations affect the state distribution at later time points. We applied the MDFP analysis to a model of signal transduction pathway involved in TRAIL (tumor necrosis factor-related apoptosis-inducing ligand)-induced apoptosis in HeLa cells. The MDFP analysis showed that caspase-8 activation regulates the timing of the switch-like increase of cPARP (cleaved poly(ADP-ribose) polymerase), an indicator of apoptosis. Meanwhile, the cell-to-cell variability in the commitment to apoptosis depended on mitochondrial outer membrane permeabilization (MOMP) and events following MOMP, including the release of Smac (second mitochondria-derived activator of caspases) and cytochrome-C from mitochondria, the inhibition of XIAP (X-linked inhibitor of apoptosis) by Smac and the formation of apoptosome.
REVIEW | doi:10.20944/preprints202302.0058.v1
Subject: Life Sciences, Virology Keywords: HIV-1 PR; host factors; host cell shut-off; protease; antiviral therapy; cell death; apoptosis
Online: 3 February 2023 (04:42:32 CET)
The human immunodeficiency virus 1 (HIV-1) viral protease (PR) is one of the most studied viral enzymes, and approval of drugs targeting its catalytic activity opened the door to the develop-ment of highly active antiretroviral therapy (HAART). Despite the fact that its crucial role in viri-on maturation is well characterized, an increasing body of research is starting to focus on its abil-ity to cleave host cell proteins, based on recent advances in proteomics and genomics technologies. Such findings are apparently in contrast with the dogma of HIV-1 PR activity being restricted to the interior of nascent virions, and suggest catalytic activity within the host cell environment. Given the limited amount of PR present in the virion at the time of infection, it is tempting to specu-late that such events mainly occur during viral late gene expression, mediated by newly synthe-sized Gag-Pol polyprotein precursors, rather than at a very early stage of infection, before pro-viral integration. Among cellular targets of HIV-1 PR, three major clusters can be identified: pro-teins involved in viral and cellular translation, those controlling cell survival, and restriction fac-tors responsible for innate/intrinsic antiviral responses. Indeed, by cleaving host cell translation initiation factors HIV-1 PR can impair cap-dependent translation, thus promoting IRES-mediated translation of late viral transcripts and viral production, while by targeting several apoptotic fac-tors it modulates cell survival, thus promoting immune evasion and viral dissemination. Addi-tionally, HIV-1 PR counteracts restriction factors incorporated in the virion that would otherwise interfere with nascent virus vitality. Thus, HIV-1 PR appears to modulate host cell function at dif-ferent times and locations during its life cycle, to ensure efficient viral persistency and propaga-tion. This kind of PR-mediated host cell modulation is found in a plethora of different viruses and HIV-1 is no exception, and although we are far from having a complete picture, it is clear that the PR has a multifaceted role in interfering with host machineries to better suit viral replication, and is a field that needs to be explored further.
ARTICLE | doi:10.20944/preprints202206.0393.v1
Subject: Earth Sciences, Palaeontology Keywords: ostracods; Carboniferous; Mississippian; Tin Mountain Limestone; Death Valley; California; Acratia; Bairdia; Ceratobairdia; Kirkbya; Rectobairdia; Silenites
Online: 29 June 2022 (03:50:33 CEST)
Silicified ostracods from the Lower Carboniferous (Lower Tin Mountain Limestone; Kinderhookian-early Osagean; 350-358.9 Ma) of Lost Burro Gap, Death Valley region, Inyo County, California, USA augment the diversity of Paleozoic ostracods of western North America. Acid maceration of pelmatozoan, micritic and silicate clay-rich micritic marine limestones yielded the following palaeocopid and podocopid ostracods: Acratia spp., Bairdia quasilecta Bushmina, 1975, Bairdia sp. cf. B. orientalis, Ceratobairdia sp., Kirkbya panamintensis sp. nov., Rectobairdia sp. cf. R. legumen, and Silenites sp. This is the first report of Ceratobairdia and Silenites from the Tin Mountain Limestone. These ostracods occupied a Panthalassan carbonate ramp environment, and represent part of a fauna that was widespread in shallow marine waters of Panthalassa.
ARTICLE | doi:10.20944/preprints202201.0227.v1
Subject: Behavioral Sciences, Other Keywords: Bayesian inference; race and ethnicity imputation; All Payer Claims Database; vital statistics death records; validation
Online: 17 January 2022 (12:40:15 CET)
Background: All Payer Claims Databases (APCD) are a rich source of health information, however, race and ethnicity (R&E) data are largely missing. Bayesian Improved Surname Geocoding (BISG) is a common R&E imputation method, yet, validation of BISG in APCDs is lacking. We used the BISG to impute missing R&E in the Oregon APCD. Methods: BISG imputed R&E for Asian Pacific Islanders (API), Blacks, Hispanics and Whites were contrasted to the gold standard (vital statistics) and sensitivity and specificity improvements were assessed. Logistic regression examined whether missing R&E was random across patient characteristics. Results: Among 85,857 individuals in the study, 32.1% (n=27,594) had missing R&E. Missing R&E was not randomly distributed. There were higher odds of missingness among males, Whites, those age 65 and older, and commercially insured individuals. Differences in the percent missing were also found by co-morbid conditions and mortality causes. Imputing the missing R&E with BISG method improved the sensitivity to identify White, Black, API, and Hispanics. Conclusions: APCDs can benefit from enhancing missing R&E with BISG imputation to perform more robust population-health level analyses and identify inequities according to R&E without losing power or dropping non-random records with missing R&E data.
ARTICLE | doi:10.20944/preprints202103.0620.v1
Subject: Medicine & Pharmacology, Veterinary Medicine Keywords: risk factors; longevity, death; euthanasia; retirement; longitudinal; TeamMate; working dogs; herding dogs; working farm dogs
Online: 25 March 2021 (14:24:34 CET)
Working farm dogs are essential to many livestock farmers. Little is known about factors that influence dogs’ risk of being lost from work. This paper explores risk factors for farm dogs being lost through death, euthanasia and retirement. All enrolled dogs were working and minimum 18 months old. Five data collection rounds were done over four years. Data about dogs were collected from owners and dogs were given physical examinations by veterinarians. Dogs that were lost from work were counted and owner-reported reasons for loss were recorded. Multivariable logistic regression modelling was used to investigate risk factors for loss. Of 589 dogs, 81 were lost from work. Of these, 59 dogs died or were euthanized and 22 were retired. Farm dogs tended to reach high ages, with 38% being 10 years or older when last examined. Acute injury or illness was the most commonly owner-reported reason for loss. Age group (P < 0.0001) and lameness (P = 0.04, OR = 1.8) significantly affected dogs’ risk being lost. These results expand our knowledge about factors that affect health, welfare and work in farm dogs. Further investigation into reasons for lameness may help improve health and welfare in working farm dogs.
REVIEW | doi:10.20944/preprints202202.0022.v1
Subject: Life Sciences, Immunology Keywords: exosomes; T lymphocytes; immune synapse; secretory granules; multivesicular bodies; cytotoxic activity; cell death; CAR T lymphocytes
Online: 1 February 2022 (21:33:57 CET)
Extracellular vesicles (EV) are a very heterogeneous group of cell-derived vesicles released by almost all kind of living cells. EV are involved in intercellular communication, both locally and systemically, since they induce signals and transfer their contents (proteins, lipids, RNAs) to other cells, which subsequently trigger a wide variety of biological responses in the target cells. How-ever, cell surface receptor-induced EV release is limited to cells from the immune system, includ-ing T lymphocytes. T cell receptor activation of T lymphocytes induces secretion of EV containing T cell receptor for antigen and several bioactive molecules, including proapoptotic proteins. These EV are thus specific for antigen-bearing cells, which make them ideal candidates for a cell-free, EV-dependent cancer therapy. In this review we discuss the generation of EV by T lymphocytes and some potential therapeutic approaches of these EV.
REVIEW | doi:10.20944/preprints202012.0419.v1
Subject: Medicine & Pharmacology, Allergology Keywords: immune checkpoint; lymphoid neoplasms; programmed death 1; cytotoxic T-lymphocyte antigen 4; monoclonal antibodies; combination therapies
Online: 17 December 2020 (08:10:05 CET)
Immunotherapy has been considered for years as a viable and attractive treatment option for patients with cancer. Among immunotherapy arsenal, the targeting of intratumoral immune cells by immune-checkpoint inhibitory agents has recently revolutionized the treatment of several subtypes of tumours. These approaches aimed at restoring an effective anti-tumour immunity, rapidly reached the market thanks to the simultaneous identification of inhibitory signals that dampen an effective antitumor response in a large variety of neoplastic cells, and the clinical development of monoclonal antibodies targeting checkpoint receptors. Leading therapies in solid tumours are mainly focused on the cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4) and programmed-death 1 (PD-1) pathways. These approaches have found a promising testing ground in both Hodgkin lymphoma and non-Hodgkin lymphoma, mainly because in these diseases the malignant cells interact with the immune system and commonly provide signals that regulate immune function. Although several trials have already demonstrated evidence of therapeutic activity with some checkpoint inhibitors in lymphoma, many of the immunologic lessons learned from solid tumours may not directly translate to lymphoid malignancies. In this sense, the mechanisms of effective antitumor responses are different between the different lymphoma subtypes, while the reasons for this substantial difference remain partially unknown. This review will discuss the current advances of immune-checkpoint blockade therapies in B-cell lymphoma and will build a projection of how the field may evolve in the near future. In particular, we will analyze the current strategies being evaluated both preclinically and clinically with the aim to foster the use of immune-checkpoint inhibitors in non-Hodgkin lymphoma, including combination approaches with chemotherapeutics, biological agents and/or different immunologic therapies.
REVIEW | doi:10.20944/preprints201810.0385.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Parkinson’s disease; cell death; dopaminergic neurons; Wnt/β-catenin signaling; glia-neuron crosstalk; neurodegeneration; neuroprotection; neurorepair
Online: 17 October 2018 (12:28:35 CEST)
Wingless-type MMTV integration site (Wnt) signaling is one of the most critical pathways in developing and adult tissues. In the brain, Wnt signaling contributes to different neurodevelopmental aspects ranging from differentiation, axonal extension, synapse formation, neurogenesis and neuroprotection. Canonical Wnt signaling is mediated mainly by the multifunctional β-catenin protein which is a potent co-activator of transcription factors such as Lymphoid Enhancer Factor (LEF) and T Cell Factor (TCF). Accumulating evidence points to dysregulation of Wnt/β-catenin signaling in major neurodegenerative disorders. Here I focus on a “Wnt/β-catenin-glial connection” in Parkinson’s disease (PD), the most common movement disorder characterized by the selective death of midbrain dopaminergic (mDAergic) neuronal cell bodies in the subtantia nigra pars compacta (SNpc) and gliosis. I will summarize the work of the last decade documenting that Wnt/β-catenin signaling in partnership with glial cells is critically involved in each step and at every levels in the regulation of nigrostriatal DAergic neuronal health, protection and regeneration in the MPTP mouse model of PD, focusing on Wnt/β-catenin signaling to boost a full neurorestorative program in PD.
ARTICLE | doi:10.20944/preprints202108.0565.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: primary prevention of sudden cardiac death; non-ischemic cardiomyopathy; ischemic cardiomyopathy; appropriate ICD therapy; mortality rate comparison
Online: 31 August 2021 (11:26:43 CEST)
(1) Background: In patients suffering from heart failure, the main causes of death are either he-modynamic failure, or ventricular arrhythmias. The only tool to significantly reduce arrhythmic sudden death is the implantable cardioverter defibrillator (ICD), but not all patients benefit to the same extend of these devices. (2) Methods: The primary outcome of this single center study was defined as cardiovascular death in patients with ischemic and non-ischemic heart failure who have benefited from ICD therapy. The secondary outcomes were death from any cause, sudden cardiac death, ICD-related therapies (appropriate antitachycardia pacing or shock therapy for ventricular tachycardia or fi-brillation) and recurrences of ventricular tachyarrhythmias. (3) Results: A total of 403 consecutive ICD recipients – symptomatic heart failure patients with ICD for the primary prevention of sudden cardiac death – were included retrospectively: 59% is-chemic cardiomyopathy (ICMP) and 41% non-ischemic cardiomyopathy (NICMP). Within a median follow-up period of 36 months, the incidence of cardiovascular mortality was not signif-icantly different in patients with NICMP and ICMP: the primary outcome had occurred in 9 pa-tients (5.4%) in the NICMP group and in 14 patients (5.9%) in the ICMP group (hazard ratio 1; 95%confidence interval [CI] 0.45 to 2.28; p =0.97). All-cause mortality occurred in 14 of 166 pa-tients (8.4%) in NICMP group and 18 of 237 patients (7.6%) in ICMP group. Sudden cardiac death occurred in 2 patients (1.2%) in the NICMP group and in 4 patients (1.7%) in the ICMP group (hazard ratio 0.71; 95% CI, 0.13 to 3.88; P=0.69). The rate of appropriate device therapies was comparable in both groups. (4) Conclusion: In this study, ICD implantation for primary prevention of sudden cardiac death in patients with symptomatic systolic heart failure was associated with similar rates of cardiovas-cular and all-cause mortality in patients with ischemic heart disease, and in patients with heart failure from other causes. NICMP and ICMP showed comparable rates of recurrent ventricular tachyarrhythmias and appropriate ICD therapies.
ARTICLE | doi:10.20944/preprints202107.0707.v1
Subject: Behavioral Sciences, General Psychology Keywords: Palliative care; Meaning therapy; CALM therapy; COVID-19; Existential positive psychology; Good death; wellbeing; mature happiness; flourishing
Online: 30 July 2021 (14:27:09 CEST)
The COVID-19 pandemic has exposed the inadequacies of the current healthcare system and needs a paradigm change, which is holistic, and community based illustrated by the healing wheel. The present paper proposes that existential positive psychology (PP 2.0) represents a promising approach to meet the rising needs in palliative care. This framework has a twofold emphasis on (a) How to transcend and transform suffering as the foundation for wellbeing, and (b) how to cultivate our spiritual and existential capabilities to achieve personal growth and flourishing. We propose that these objectives can be achieved simultaneously through dialectical palliative counselling, as illustrated by Wong’s integrative meaning therapy (Wong, 2020) and Lo’s Conceptual Model of CALM Therapy in palliative care (Lo et al., 2014). We then discuss existential suffering in general and at the last stage of life in particular; we also review recent research and interventions on existential suffering in palliative patients. Finally, we outline the objectives and the strategies of IMT in providing palliative counselling for palliative care and hospice patients.
REVIEW | doi:10.20944/preprints202004.0122.v2
Subject: Life Sciences, Immunology Keywords: melatonin; coronavirus; pandemic; SARS-CoV-2; bat; lung; apoptosis; programmed cell death; mortality; morbidity; COVID-19; drug
Online: 9 April 2020 (09:24:47 CEST)
The current COVID-19 pandemic is one of the most devastating events in recent history. The virus causes relatively minor damage to young, healthy populations, imposing life-threatening danger to the elderly and people with diseases of chronic inflammation. Therefore, if we could reduce the risk for vulnerable populations, it would make the COVID-19 pandemic more similar to other typical outbreaks. Children don’t suffer from COVID-19 as much as their grandparents and have a much higher melatonin level. Bats are nocturnal animals possessing high levels of melatonin, which may contribute to their high anti-viral resistance. Viruses induce an explosion of inflammatory cytokines and reactive oxygen species, and melatonin is the best natural antioxidant that is lost with age. The programmed cell death coronaviruses cause, which can result in significant lung damage, is also inhibited by melatonin. Coronavirus causes inflammation in the lungs which requires inflammasome activity. Melatonin blocks these inflammasomes. General immunity is impaired by anxiety and sleep deprivation. Melatonin improves sleep habits, reduces anxiety and stimulates immunity. Fibrosis may be the most dangerous complication after COVID-19. Melatonin is known to prevent fibrosis. Mechanical ventilation may be necessary but yet imposes risks due to oxidative stress, which can be reduced by melatonin. Thus, by using the safe over-the-counter drug melatonin, we may be immediately able to prevent the development of severe disease symptoms in coronavirus patients, reduce the severity of their symptoms, and/or reduce the immuno-pathology of coronavirus infection on patients’ health after the active phase of the infection is over.
REVIEW | doi:10.20944/preprints202007.0681.v1
Subject: Keywords: asymptomatic disease; communicability; COVID-19; death rate; Ro; SARS-CoV-2; social distancing; transmission rate; infection rate; quarantine
Online: 28 July 2020 (11:57:26 CEST)
Decisions affecting the COVID-19 pandemic, by the individual and those with highest authority, are being made on the basis of unreliable data. Data about cases and deaths are collected daily but represent only a sample of reality. Statistics convert sample data into more reliable estimates. However, statistics have no magical powers; reliability requires dependable data. It is futile to rail against this darkness; COVID-19 is not a scientific experiment. However, we must do better both with data collection and data analysis. In this review, I focus on one element of the data, the asymptomatic case of COVID-19. Without reliable information about this number, decision makers are significantly blinded. By its nature, the asymptomatic case is hidden but contaminating to understanding COVID-19. The true case rate and death rate per case are unknowable without knowing the fraction of cases that are asymptomatic. The best estimate of asymptomatic cases is in the CDC document: COVID-19 Pandemic Planning Scenarios. For four different scenarios the estimates range from 10% to 70%, with the best estimate of 40% for asymptomatic cases. However, even the definition of the asymptomatic case is problematic. In simplest terms, two elements are required: an infection and no symptoms. How is “no symptoms” to be usefully defined? It appears to be analogous to pontificating about black swans from studying only white swans. It implies infection, but how is infection defined? Is it presence of the virus, replication of the virus, or presence of antibodies? Is asymptomatic disease an oxymoron? Without extensive, purposeful screening for specifically defined, essential symptoms and appropriate virus and antibody testing over time, the class of asymptomatic cases remains unknown. Current estimates range from <20% to ˃80%. If low, it can be ignored; if high, it dramatically and proportionately lowers the case rate and the death rate per case. Consequentially, the asymptomatic rate dramatically affects our societal and political responses. In this focused review, we assess the limitations of the published estimates, bring attention to the importance of obtaining accurate data, and exhort that high priority be given in the scientific community to understanding the issue, asymptomatic COVID-19 cases.
ARTICLE | doi:10.20944/preprints201908.0182.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: indirubin-3′-monoxime; p53; death receptor 5; TNF-related apoptosis-inducing ligand; transcription factor C/EBP homologous protein
Online: 17 August 2019 (04:19:38 CEST)
Indirubin-3′-monoxime (I3M) exhibits anti-proliferative activity in various cancer cells; however, its anti-cancer mechanism remains incompletely elucidated. This study revealed that I3M promotes the expression of death receptor 5 (DR5) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in HCT116 p53+/+ cells, resulting in caspase-mediated apoptosis. However, this study demonstrated that HCT116 p53-/- cells are insensitive to I3M-mediated apoptosis, indicating that I3M-induced apoptosis depends on the p53 status of HCT116 cells. Additionally, in HCT116 p53-/- cells, I3M significantly increased Ras expression, while in HCT116 p53+/+ cells, it reduced Ras expression. Furthermore, I3M remarkably increased the production of reactive oxygen species (ROS), which were reduced in transient p53 knockdown, indicating that I3M-mediated apoptosis is promoted by p53-mediated ROS production. Our results also showed that I3M enhanced transcription factor C/EBP homologous protein (CHOP) expression, resulting in endoplasmic reticulum (ER) stress-mediated DR5 expression, which is upregulated by ROS production in HCT116 p53+/+ cells. Moreover, co-treatment with TRAIL synergistically enhanced I3M-induced DR5 expression, thereby triggering TRAIL-induced apoptosis of HCT116 p53+/+ cells, which was interfered by a DR5-specific blocking chimeric antibody. In summary, I3M potently enhances TRAIL-induced apoptosis by upregulating DR5 expression via p53-mediated ROS production in HCT116 p53+/+ cells. However, HCT116 p53-/- cells were resistant to I3M-mediated apoptosis, suggesting that I3M could be a promising anti-cancer candidate against TRAIL-resistant p53+/+ cancer cells.
ARTICLE | doi:10.20944/preprints202209.0417.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: Recreational substance abuse; drug abuse; marijuana; amphetamine; acute ischemic stroke; risk factors; young adult; NIS; Stroke; Sudden Cardiac Death
Online: 27 September 2022 (09:41:00 CEST)
Background: Substance use continues to be on the rise in the United States and has been linked to new onset cardiovascular (CVDs) and cerebrovascular disorders (CeVDs) leading to hospitalizations. We aimed to study the association of different subtypes of substance use disorders (SUDs) among hospitalized patients, with the different subtypes of CVDs and CeVDs, using the National Inpatient Sample (NIS) Database. Additionally, we aimed to assess the odds of hospitalizations with new onset CVDs and CeVDs among patients with different types of SUDs. Methods: A retrospective study of the NIS database (2016-2017) using the ICD-10-CM codes was performed. The hospitalizations with a secondary diagnosis of SUDs were identified. Weighted univariate analysis using the chi-square test and multivariate survey logistic regression analysis was performed to evaluate for the incidence, prevalence, and odds of association between vascular events and SUDs. Results: There were a total of 58,259,589 hospitalizations, out of which 21.42% had SUDs. Out of all the hospitalized patients between the age 18-50, more patients had SUDs than not (31.83%, p< 0.0001). This difference existed for all the different subtypes of SUDs including alcohol related disorder (42.61%), amphetamine dependence (76.17% vs 31.83%), cannabis related disorder (75.17%), cocaine related disorders (57.87%), hallucinogen related disorder (82.91%), inhalant related disorders (67.25%), opioid related disorders (52.86%), and nicotine dependence (35.72%). We found a significant association of acute ischemic stroke with amphetamine dependence (OR 1.23, 95%CI 1.14-1.33), cocaine related disorders (1.17, 1.12-1.23) and nicotine dependence (1.42, 1.40-1.43). Similarly, the association of intracerebral hemorrhage was higher with amphetamine dependence (2.58, 2.26-2.93), and cocaine related disorders (1.62, 1.46-1.79). The association of subarachnoid hemorrhage was noted to be higher with amphetamine dependence (1.82, 1.48-2.24) and nicotine dependence (1.47, 1.39-1.55). In terms of association of cardiovascular disorders with SUDs,the patients with myocardial infarction had higher odds of nicotine dependence (1.85, 1.83-1.87) than not, Similarly, the patients with angina pectoris were noted to have a higher association with cocaine related disorders (2.21, 1.86-2.62), and those with atrial fibrillation had a higher association alcohol related disorders (1.14, 1.11-1.17). Conclusion: Our study demonstrates the variability of CVD and CeVD in patients hospitalized for SUD. Findings from our study may help promote increased awareness and early management of these events. Further studies are needed to evaluate specific effects of frequency and dose on the incidence and prevalence of CVD and CeVD in patients with SUD.
REVIEW | doi:10.20944/preprints202109.0167.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: extracellular vesicles; exosomes; microvesicles; apoptotic bodies; apoptotic extracellular vesicles; cell death; inflammation; sepsis; lung inflammatory disorders; SARS-CoV-2
Online: 9 September 2021 (10:31:49 CEST)
Extracellular vesicles (EVs) have been identified as novel mediators of intercellular communication. They work via delivering the sequestered cargo to cells in close vicinity as well as distant sites in the body, regulating pathophysiological processes. Cell death and inflammation are biologically crucial processes in both normal physiology and pathology. These processes are indistinguishably linked with their effectors modulating the other process. For instance, during an unresolvable infection, the upregulation of specific immune mediators leads to inflammation causing cell death and tissue damage. EVs have gained considerable interest as mediators of both cell death and inflammation during conditions such as sepsis. This review summarizes the types of extracellular vesicles known to date and their roles in mediating immune responses leading to cell death and inflammation with specific focus on sepsis and lung inflammation.
ARTICLE | doi:10.20944/preprints202007.0346.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; deaths; doctor; nurse; pharmacist; healthcare worker; frontline; occupational risk; suicide; violent death; accident; pandemic; SARS-CoV-2
Online: 16 July 2020 (08:28:55 CEST)
Background: Over 900,000 cases of COVID-19 and 23,000 deaths have been reported till 13 July in India. Preserving the limited healthcare workforce is part of the strategy against the pandemic. Mortality and morbidity data have a role in customising this strategy. At this time, there is no published study on COVID-related mortality among doctors or other healthcare workers in India. Methods: A multi-pronged search was made for all reported deaths linked with COVID-19 among doctors in India. Details of COVID-linked deaths reported by mainstream media and by multiple professional social media sources were collected, screened, verified and analysed. Violent deaths occurring in the setting of pandemic-related work were separately listed. Deaths from other diseases were excluded. Results: Among 108 COVID-linked deaths among doctors, there were four pandemic-related violent deaths including three road accidents and a suicide. Of the 104 non-violent deaths, 55.5% were below 60 years of age, while 29.6% and 21% were below the age of 50 and 40 respectively. The average age at death was 56.3 (range 22 - 96). Over half of the deaths occurred among general practitioners, while surgical specialties accounted for 27% of the mortality. The geographic distribution of deaths of doctors correlated with the reported number of COVID-19 patients in each state. The total number of COVID-related healthcare worker deaths was 136, out of which eight (5.8%) were violent, and occurred in young individuals with an average age of 27.8 years. Conclusions: The majority of the 104 COVID-related non-violent deaths among doctors (55.5%) occurred below the age of 60. The average at death was 56.6 years. The states with highest number of COVID-19 cases had greater number of doctor deaths. Violent deaths among young healthcare workers in the setting of the pandemic requires special attention.
Subject: Biology, Other Keywords: stress granules; G3BP1; G3BP2; Caprin-1; USP10; TIA1; TIAR; cancer prognosis; biomarker; metastasis; resistance; cell death; pro-survival properties
Online: 7 April 2020 (01:56:12 CEST)
Stress Granules formation is a pro-survival mechanism helping cells to cope with environmental challenges. Stress Granules have been studied for two decades in fundamental research, and are now being examined in the context of human pathogenesis. Here, we review studies highlighting stress granules’ involvement in cancer development through translational pattern modification.
ARTICLE | doi:10.20944/preprints201909.0324.v1
Subject: Materials Science, Nanotechnology Keywords: immunotherapy; human hepatoma cells; programmed cell death protein 1 (pd-1); magnetic nanoparticles; peptide-imprinted polymer; natural killer cells
Online: 29 September 2019 (05:28:46 CEST)
Programmed cell death protein 1 (PD-1) is a biomarker on the surface of cells that has a role in promoting self-tolerance by suppressing the inflammatory activity of T cells. In this work, one peptide of PD-1 was used as the template in molecular imprinting. The magnetic peptide-imprinted poly(ethylene-co-vinyl alcohol) composite nanoparticles (MPIP NPs) were characterized by dynamic light scattering (DLS), high-performance liquid chromatography (HPLC), Brunauer-Emmett-Teller (BET) analysis and superconducting quantum interference device (SQUID) analysis. Natural killer-92 (NK-92) cells were added to these composite nanoparticles and then incubated with human hepatoma (HepG2) cells. The viability and apoptosis pathway of HepG2 were then studied using cell counting kit-8 (CCK8) and the quantitative real-time polymerase chain reaction (qRT-PCR), respectively. These nanoparticles were found significantly enhance the activity of natural killer cells toward HepG2 cells by increasing expression of NK-kB, caspase 8 and especially caspase 3.
ARTICLE | doi:10.20944/preprints202211.0480.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19 death rates; COVID-19 vaccines; hydroxychloroquine; ivermectin; rates of COVID-19 testing; containment measures; social distancing; travel restriction,
Online: 25 November 2022 (10:16:41 CET)
Objectives to assess COVID-19 mortality rates per country population. To determine what if any independent country-specific variables from 9 different databases were correlated. Design population based retrospective cohort study. Setting analysis of global COVID-19 treatment and containment strategies using data from 9 worldwide websites. Participants 108 countries worldwide. Interventions none. Main Outcome Measures were COVID-19 death rates per country population analyzed by univariate and multivariate analysis. The main outcome parameters were to determine if there are any correlations between the percentage of countrywide COVID-19 deaths/population by the countries’ percent vaccinated. Secondary outcome measures include the effect of other independent variables on COVID-19 death rates per country population including: health expenditures per capita, annual income per capita, COVID-19 tests per 1000 people, stringency index (a measure of each countries containment strategies), hydroxychloroquine score (a measure of each countries use), ivermectin score (a measure of each countries use), hypertension, obesity, diabetes, and specific countries and geographic locations. Results COVID-19 vaccination rates ranged from 0-99% in 108 countries. Univariate analysis demonstrates the following independent variables to correlate with COVID-19 deaths/population (correlation coefficient, p value): countrywide COVID-19 vaccination rates (+0.2936, p=0.002); healthcare costs per capita (+0.3212, p=0.0007), income per capita (+0.3051, p=0.0013), COVID-19 tests per 1000 population (+0.6981 p=0.0307); stringency index (+0.3098, p=0.0011); hydroxychloroquine index (-0.1337, p=0.0678); and ivermectin index (-0.1383, p=0.1535). Conclusions Increasing rates of COVID-19 vaccination are associated with increase COVID-19 death rates per country population (p=0.002). Other variables associated include healthcare costs per capita (+0.3212, p=0.0007), income per capita (+0.3051, p=0.0013), COVID-19 tests per 1000 population (+0.6981 p=0.0307); and stringency index (+0.3098, p=0.0011).
ARTICLE | doi:10.20944/preprints201810.0530.v1
Subject: Biology, Other Keywords: poor blood circulation; Ecklonia cava; phlorotannins; pyrogallol-phloroglucinol-6,6-bieckol; functional ingredients; endothelial cell death; vascular smooth muscle cell proliferation and migration; inflammation
Online: 23 October 2018 (09:39:50 CEST)
Ecklonia cava (E.cava) can alleviate vascular dysfunction in diseases associated with poor circulation. E. cava contains various polyphenols with different functions, but few studies have compared the effects of these polyphenols. Here, we comparatively investigated four major compounds present in an ethanoic extract of E. cava. These four major compounds were isolated and their effects were examined on monocyte-associated vascular inflammation and dysfunctions. Pyrogallol-phloroglucinol-6,6-bieckol (PPB) significantly inhibited monocyte migration in vitro by reducing levels of inflammatory macrophage differentiation and of its related molecular factors. In addition, PPB protected against monocyte-associated endothelial cell death by increasing the phosphorylations of PI3K-AKT and AMPK, decreasing caspase levels, and reducing monocyte-associated vascular smooth muscle cell proliferation and migration by decreasing the phosphorylations of ERK and AKT. The results of this study show that four compounds were effective for reduction of monocyte-associated vascular inflammation and dysfunctions, but PPB might be more useful for the treatment of vascular dysfunction in diseases associated with poor circulation.
ARTICLE | doi:10.20944/preprints201907.0344.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: diet quality; neighborhood deprivation; Japanese areal deprivation index; neighborhood socioeconomic status; hazard ratios; mortality; Japanese Food Guide Spinning Top; well-balanced diet; early death
Online: 31 July 2019 (04:26:11 CEST)
Individuals residing in more deprived areas have a lower diet quality. While several studies have shown that individuals with a lower diet quality have a higher mortality risk, a low quality diet might also lead to poor health in highly deprived areas. We aimed to examine the association between deprivation within an area and all-cause mortality risk according to diet quality. Methods: We conducted a population-based prospective study on 27994 men and 33273 women aged 45–75 years. Neighborhood deprivation was assessed using the Japanese areal deprivation index (ADI). Dietary intakes were assessed using a validated 147-item food frequency questionnaire. Subsequently, Japanese Food Guide Spinning Top scores were calculated. Hazard ratios (HR) and 95% confidence intervals (CI) of mortality were calculated according to tertiles of ADI by diet quality score. Results: Individuals residing in the most deprived area had the lowest dietary scores. During the 16.7-year follow-up, compared to individuals with a high quality diet residing in the least deprived area, individuals with a low quality diet had a higher risk of mortality according to increment of ADI (P trend = 0.02); the multivariate adjusted HR (95% CI) was 1.07 (1.00-1.15), 1.15 (1.07-1.24), and 1.18 (1.08-1.29) in those residing in the lowest through the highest third of ADI, respectively. However, individuals with a high quality diet had no significant association between ADI and mortality (P trend =0.87). Conclusion: A well-balanced diet may prevent early death associated with neighborhood socioeconomic status among those residing in highly deprived areas.
REVIEW | doi:10.20944/preprints201809.0281.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: axon guidance; growth cone; cytoskeleton; caspases; apoptosis; signal integration; basal level of caspase activity; death associated inhibitor of apoptosis; axon branching; Netrin; DCC; frazzled; slit; robo; Drosophila
Online: 16 September 2018 (09:43:52 CEST)
Navigating growth cones are exposed to multiple signals simultaneously and have to integrate competing cues into a coherent navigational response. Integration of guidance cues is traditionally thought to occur at the level of cytoskeletal dynamics. Drosophila studies indicate that cells exhibit a low level of continuous caspase protease activation, and that axon guidance cues can activate or suppress caspase activity. We base a model for axon guidance on these observations. By analogy with other systems in which caspase signaling has non-apoptotic functions, we propose that caspase signaling can either reinforce repulsion or negate attraction in response to external guidance cues by cleaving cytoskeletal proteins. Over the course of an entire trajectory, incorrectly navigating axons may pass the threshold for apoptosis and be eliminated, whereas axons making correct decisions will survive. These observations would also explain why neurotrophic factors can act as axon guidance cues and why axon guidance systems such as Slit/Robo signaling may act as tumor suppressors in cancer.
REVIEW | doi:10.20944/preprints202203.0103.v1
Subject: Biology, Plant Sciences Keywords: plant immune response; reactive oxygen species; salicylic acid; reactive oxygen species-salicylic acid crosstalk; programmed cell death; hypersensitive response-conferred resistance; RBOH NADPH oxidases; chloroplastic redox state; biosensors; precision transcriptomics
Online: 7 March 2022 (14:46:28 CET)
One of the earliest hallmarks of plant immune response is production of reactive oxygen spe-cies (ROS) in different subcellular compartments, which regulate plant immunity. A suitable equilibrium, which is crucial to prevent ROS over-accumulation leading to oxidative stress, is maintained by salicylic acid (SA), a chief regulator of ROS. However, ROS are not only acting downstream of SA signaling, but were also proposed to be a central component of a self-amplifying loop that regulates SA signaling as well as the interaction balance between dif-ferent phytohormones. The exact role of this crosstalk, the position where SA interferes with ROS signaling and ROS interferes with SA signaling and the outcome of this regulation depend on the origin of ROS but also on the pathosystem. The precise spatiotemporal regulation of or-ganelle specific ROS and SA levels determine the effectiveness of pathogen arrest and is there-fore crucial for a successful immune response. However, the regulatory interplay behind still remain poorly understood, as up till now, the role of organelle specific ROS and SA in HR-conferred resistance has mostly been studied by altering the level of a single component. In order to address these aspects, a sophisticated combination of research methods for monitoring the spatiotemporal dynamics of key players and transcriptional activity in plants is needed, and will most probably consist of biosensors and precision transcriptomics.
HYPOTHESIS | doi:10.20944/preprints202106.0598.v1
Subject: Keywords: Plant communication; Binary digits; Vector-tensor-scalar geometry; Mobius strip; Figure-8 Klein bottle; Consciousness; Electromagnetic-gravitational interaction; Higgs boson; Artificial Intelligence; Quantum Gravity; Theory of Everything, Life after death/before life (before conception)
Online: 24 June 2021 (10:20:25 CEST)
According to Swiss-American Doctor of Sciences and Agricultural Engineer Jean-Pierre Jost, "plants communicate with each other by the quality of light emitted by their leaves or by means of stress hormones and other volatile chemicals. They also make use of cocktails of chemicals, pheromones, shape and colors to attract pollinators whereas other signals repel unwanted organisms. Insects are able to decode such messages and respond accordingly. Plants are apparently also communicating by sounds and electric signals." (1) How do plants do these things? Of course, it's easy to imagine it's all purely mechanical. But at the risk of sounding like a mysticism fanatic, I wonder if plants' activities are part of a spectrum of consciousness that pervades the entire universe. This spectrum would result from everything in the universe having the BITS or BInary digiTS of electronics as their ultimate composition. As explained in this hypothesis, something I call vector-tensor-scalar geometry is essential to my hypothesis. VTS geometry produces the particles of chemicals and pheromones, and refers to communication via electric signals when it speaks of electromagnetic-gravitational interaction. There's another consequence if everything in the universe is ultimately composed of electronic BITS and the cosmos is a spectrum of consciousness/artificial intelligence. It's impossible for an absence of consciousness to exist, either after death or before conception.
REVIEW | doi:10.20944/preprints202211.0271.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: cisplatin; carboplatin; oxaliplatin; cellular uptake; DNA damage; transcription regulation; non-nuclear targets; chemoresistance; mechanisms of action; clinical usages; influx and efflux pumps; ribosome biogenesis; ER stress response; immunogenic cell death; interstrand and intrastrand DNA cross-links.
Online: 15 November 2022 (03:38:06 CET)
Cisplatin (CDDP), carboplatin (CP), and oxaliplatin (OXP) are three platinating agents clinically approved worldwide for use against a variety of cancers. They are canonically known as DNA damage inducers; however, that is only one of their mechanisms of cytotoxicity. CDDP mediates its effects through DNA damage-induced transcription inhibition and apoptotic signalling. In addition, CDDP targets the endoplasmic reticulum (ER) to induce ER-stress, the mitochondria via mitochondrial DNA damage leading to ROS production, and the plasma membrane and cytoskeletal components. CP acts in a similar fashion to CDDP by inducing DNA damage, mitochondrial damage, and ER stress. Additionally, CP is also able to upregulate micro-RNA activity, enhancing intrinsic apoptosis. OXP, on the other hand, at first induces damage to all the same targets as CDDP and CP, yet it is also capable of inducing immunogenic cell death via ER stress and can decrease ribosome biogenesis through its nucleolar effects. In this comprehensive review, we provide detailed mechanisms of action for the three platinating agents, going beyond their nuclear effects to include their cytoplasmic impact within cancer cells. In addition, we cover their current clinical use and limitations, including side effects and mechanisms of resistance.
REVIEW | doi:10.3390/sci2030068
Subject: Keywords: COVID-19; pooling clinical trials; hyperinfection; steroids; treatment; targeted healthcare; population health management; cancer treatment; clinical research; clinical trials; developing vaccines; ranking and rating hospital quality; school closures; interventions for delirium; assessments of COVID-19 death inequities; regulatory safeguards; preventing child abuse and maltreatment; prevalence of health care worker burnout; nursing home ratings; challenging oncology practice; addressing racial; ethnic; social and economic divides; violence against sexual minority adolescents; primary tumors; metastasis; stages of cancer; reforming cancer clinical trials; supporting carers; protection and prevention; benign and malignant tumors; reforming cancer clinical trials; protection of healthcare personnel; comparing excess deaths in NYC; 1918 influenza pandemic; the possibility of full recovery from COVID-19; mental health impact of COVID-19 on young adults; ranking and rating nursing home quali
Online: 21 August 2020 (00:00:00 CEST)
The SARS-CoV-2 virus that causes the COVID-19 disease has wreaked havoc on the world community in terms of every imaginable parameter. The research output on COVID-19 has been nothing short of phenomenal, especially in the medical and biomedical sciences, where the search for a potential vaccine is being conducted in earnest. Much of the advanced research has been distributed in the leading medical journals, including the Journal of the American Medical Association (JAMA), where the latest research is distributed on a daily basis. The purpose of this paper is to provide some perspectives on 44 interesting and highly topical research papers that have been published in JAMA, at the time of writing, within the past two weeks. The diverse topics include public health, general medicine, internal medicine, oncology, paediatrics, geriatrics, and biostatistics.
ARTICLE | doi:10.20944/preprints201810.0088.v1
Subject: Materials Science, Biomaterials Keywords: There are many molecules used as drug carrier. TUD-1 is a newly synthesized mesoporous silica (SM) molecule possess two important features; consists of mesoporous so it is very suitable to be drug carrier in addition to that it has the ability to induce apoptosis in cancer cells. However, the effect of TUD-1 appears to act as cell death inducer, regardless of whether it is necrosis or apoptosis. Unfortunately, recent studies indicate that a proportion of cells undergo necrosis rather than apoptosis, which limits the use of TUD-1 as a secure treatment. On the other hand, lithium considered as necrosis inhibitor element. Hence, current study based on the idea of production a new Li/TUD-1 by incorporated mesoporous silica (TUD-1 type) with lithium in order to produce a new compound that has the ability to activate apoptosis by mesoporous silica (TUD-1 type) and at the same time can inhibit the activity of necrosis by lithium. Herein, lithium was incorporated in TUD-1 mesoporous silica by
Online: 4 October 2018 (15:54:02 CEST)
There are many molecules used as drug carrier. TUD-1 is a newly synthesized mesoporous silica (SM) molecule possess two important features; consists of mesoporous so it is very suitable to be drug carrier in addition to that it has the ability to induce apoptosis in cancer cells. However, the effect of TUD-1 appears to act as cell death inducer, regardless of whether it is necrosis or apoptosis. Unfortunately, recent studies indicate that a proportion of cells undergo necrosis rather than apoptosis, which limits the use of TUD-1 as a secure treatment. On the other hand, lithium considered as necrosis inhibitor element. Hence, current study based on the idea of production a new Li/TUD-1 by incorporated mesoporous silica (TUD-1 type) with lithium in order to produce a new compound that has the ability to activate apoptosis by mesoporous silica (TUD-1 type) and at the same time can inhibit the activity of necrosis by lithium. Herein, lithium was incorporated in TUD-1 mesoporous silica by using sol-gel technique in one step synthesis procedure. Moreover, lithium was incorporated in TUD-1 with different loading in order to form different active sites such as isolated lithium ions, nanoparticles of Li2O, and bulky crystals of Li2O. The ability of the new compounds to induce apoptosis and prevent necrosis was evaluated on three different types of cancer cell lines which are; liver HepG-2, Breast MCF-7 and colon HCT116. The obtained results show that Li/TUD-1has the ability to control necrosis and thus reduce the side effects of treatments containing silica in the case of lithium has been added to them, especially in chronic cases. This has been demonstrated by the significant increase in the IC50 value and cell viability comparing to control groups. Consequently, the idea is new, so it definitely needs more develop and test with materials that have more apoptotic impact than silica in order to induce apoptosis without induction of necrosis.