As the global arid climate intensifies and the groundwater becomes increasingly scarce, drought stress has become a major challenge to plant growth and development worldwide, especially causing yield reduction and extinction of cultivated crops. In a large number of drought resistance studies, DNA methylation has been found dynamically associated with response to drought stress in plants by regulating gene expression and developments in plants, but the specific mechanisms are not yet clear. In this article, the current advances of research have been summarized on DNA methylation response to drought stress in various plant species, in terms of methylation detection methods, mechanisms of pattern changes (DNA de novo methylation, DNA maintenance methylation, and DNA demethylation), and its response to drought stress. With Most of the studies showed significant changes in genome or gene promoter methylation levels in plants subjected to drought stress, but the identification of the genes and pathways involved is still in the minority. The aim is to provide references for in-depth research on the response of plants to drought stress through epigenetics, and to uncover drought resistance genes regulated by DNA methylation, specific signaling pathways, and molecular mechanisms of action.

Macrophages undergo different cellular states upon activation that can be hyporesponsive (tolerated) or hyperresponsive (primed or trained) to subsequent stimuli. Epigenetic modifications are known to play a key role in determining these cellular states. However, little is known about the role of signaling pathways that lead to these epigenetic modifications. Here, we examined the effects of various inhibitors targeting key signaling pathways induced by lipopolysaccharide (LPS) on tolerance and priming in the murine macrophages. We found that a prolonged inhibition (>18 h) of the MEK1/2-ERK signaling axis reversed tolerance and primed cells in expressing IL-1β and other inflammatory cytokines such as IL-6, TNFα, and CXCL10. Ectopic expression of catalytically active and inactive MEK1 mutants suppressed and enhanced IL-1β expression, respectively. Primed cells by the MEK1/2 inhibitor U0126 expressed higher levels of gene sets associated with immune responses and cytokine/chemokine production but lower levels of genes with cell cycle progression, chromosome organization, and heterochromatin formation than non-primed cells. Of interest, expression of the histone 3 lysine 9 (H3K9) methyltransferase Suv39h1 and the H3K9 methylation reader Cbx5 was substantially suppressed, whereas the H3K9 demethylase Kdm7a was enhanced, suggesting a role of the MEK1/2-ERK signaling axis in H3K9 demethylation. The H3K9 trimethylation levels in the genomic regions of IL-1β, TNFα, and CXCL10 were decreased by U0126. Also, the H3K9 methyltransferase inhibitor BIX01294 mimicked and overexpression of Cbx5 prevented the U0126 training effects in both RAW264.7 cells and bone marrow-derived macrophages. Collectively, these data suggest that prolonged inhibition of the MEK1/2-ERK signaling axis reverses tolerance and primed macrophages likely through decreasing H3K9 methylation levels.

Background: Despite recent advances in epithelial ovarian carcinoma (EOC) treatment, recur-rence and mortality rates have not improved significantly. DNA hypermethylation has generally been associated with ominous prognosis and chemotherapy resistance, but the role of DNMTs in EOC remains to be investigated. Methods: In the current study, we systematically retrieved gene expression data from patients with EOC and studied the immunohistochemical expression of DNMTs in 108 primary and 26 relapsed tumors. Results: Our results showed that DNMT1, DNMT3A, DNMT3B and DNMT3L RNA levels were higher and DNMT2 lower in tumors compared to non-neoplastic tissue, and DNMT3A and DNMT2 expression decreased from Stage II to Stage IV carcinomas. Proteomic data also suggested that DNMT1 and DNMT3A levels were increased in tumors. Similarly, DNMT1, DNMT3A and DNMT3L protein levels were overex-pressed and DNMT2 expression was reduced in high grade carcinomas compared to non-neoplastic tissue and low-grade tumors. Moreover, DNMT1 and DNMT3L were increased in relapsed tumors compared to their primaries. DNMT3A, DNMT1 and DNMT3B mRNA lev-els were correlated with overall survival. Conclusions: Our study demonstrates that DNMT1 and DNMT3L are upregulated in primary high grade EOC and further increase in relapses, whereas DNMT3A is upregulated only in the earlier stages of cancer progression. DNMT2 downregulation highlights a presumptive tumor-suppressor activity of this gene in ovarian car-cinoma.

The α-synucleinopathies are a group of neurodegenerative diseases characterized by the deposition of α-synuclein aggregates (α-syn) in the brain. Currently, there is no suitable tracer to enable a definitive early diagnosis of these diseases. We reported candidates based on 4,4'-disarylbisthiazole (DABTA) scaffold with a high affinity towards α-syn and excellent selectivity over Aβ and tau fibrils. Based on prior in silico studies a focused library of 23 halide-containing and O-methylated DABTAs was prepared. The DABTAs were synthesized via a modified two-step Hantzsch thiazole synthesis, characterized, and used in competitive binding assays against [3H]PiB, and [3H]DCVJ. The DABTAs gave an overall chemical yield of 15 – 71%, with a calculated lipophilicity of 2.5 – 5.7. The ligands demonstrated an excellent affinity to α-syn with both [3H]PiB and [3H]DCVJ: Ki 0.1 – 4.9 nM and up to 20 – 3900-fold selectivity over Aβ and tau fibrils. It could be concluded that in-silico simulation is useful for the rational design of a new generation of DABTAs. Further investigation of the leads in the next step is encouraged: radiolabeling of the ligands with radioisotopes such as fluorine-18 or carbon-11 for in vivo, ex vivo and translational research and for further in vitro experiments on human-derived protein aggregates.

Objectives: Metabolic interactions amongst mutated genes in myelodysplastic syndrome (MDS) offer promising avenues for novel anticancer treatments. Our comprehensive study delves into these mutational and transcriptomic landscapes, pinpointing hallmark gene mutations and deregulated gene expression that could influence MDS patients’ metabolomes. Methods: The study utilized a retrospective, cross-sectional approach, employing mutational data on the cBio Cancer Genomics Portal conducted and reported by the University of Tokyo in 2011 and multi-center MDS cohorts regulated by Wellcome Trust Sanger Institute, United Kingdom, all in 2020. For transcriptomic data, we selected three publicly accessible independent cohorts on the Gene Expression Omnibus (GEO) database (GSE114922 in Wellcome Trust Centre for Human Genetics, United Kingdome, GSE63569 in University of Oxford, United Kingdome, and GSE183328 in CIMA, Spain) held in 2015, 2018, and 2022, respectively. To compile clinical, mutational, and transcriptomic data on MDS patients from multiple datasets and studies. This meta-analysis included genomic data derived from cellular genomics sources to assess mutations in specific genes, alongside an examination of transcriptomic data from three separate datasets that have been previously published. Results: DNMT3A presented a 20% mutation frequency, playing a pivotal role in MDS metabolomics. The DNMT3A gene mutations displayed significant mutual exclusivity with the SRSF2, ASXL1, JAK2, and TP53 genes. The mutational analysis also showed that the gene expression landscape in MDS is associated with alterations to DNA methylation pathways. Conclusion: This analysis suggests a potential therapeutic niche. Identifying signature genes in MDS that have metabolic and methylation affiliations could illuminate the disease's intricate biology and inspire novel treatments.

Glycosidic linkage analysis was conducted on the unfractionated polysaccharides in the alcohol-insoluble residues (AIRs) prepared from six red seaweeds (Gracilariopsis sp., Prionitis sp., Mastocarpus papillatus, Callophyllis sp., Mazzaella splendens, and Palmaria palmata) using GC-MS/FID analysis of partially methylated alditol acetates (PMAAs). The cell walls of P. palmata primarily contained mixed-linkage xylans and small amounts of sulfated galactans and cellulose. In contrast, the unfractionated polysaccharides of the other five species were rich in galactans displaying diverse 3,6-anhydro-galactose and galactose linkages with varied sulfation patterns. Different levels of cellulose were also observed. This glycosidic linkage method offers advantages for cellulose analysis over traditional monosaccharide analysis that is known for underrepresenting glucose in crystalline cellulose. Relative linkage compositions calculated from GC-MS and GC-FID measurements showed that anhydro sugar linkages generated more response in the latter detection method. This improved linkage workflow presents a useful tool for studying polysaccharide structural variations across red seaweed species. Furthermore, for the first time, relative linkage compositions from GC-MS and GC-FID measurements, along with normalized FID and total ion current (TIC) chromatograms without peak assignments, were analyzed using principal component analysis (PCA) as a proof-of-concept demonstration of the technique's potential to differentiate various red seaweed species.

Transitions from seed to seedling represent a critical developmental step in the life cycle of higher plants, dramatically affecting plant ontogenesis and stress tolerance. The release from dormancy to acquiring the germination ability is defined by a balance of phytohormones, with a substantial contribution of abscisic acid (ABA), which inhibits germination. We studied the embryonic axes of Pisum sativum L. before and after radicle protrusion. Our previous work compared RNA sequencing-based transcriptomics in the embryonic axes isolated before and after radicle protrusion. The current study aims to analyze ABA-dependent gene regulation during the transition of embryonic axes from germination to post-germination stage. First, we determined the levels of abscisates (ABA, phaseic acid, dihydrophaseic acid, and neo-phaseic acid) using the ultra-high-performance liquid chromatography-tandem mass spectrometry. Second, we made a detailed annotation of ABA-associated genes using RNA sequencing-based transcriptome profiling. Finally, we analyzed the DNA methylation pattern in the promoters of the PsABI3, PsABI4, and PsABI5 genes. We showed that changes in the abscisate profile are characterized by the accumulation of ABA catabolites, and the ABA-related gene profile is accompanied by the upregulation of genes controlling the seedling development and the downregulation of genes controlling the water deprivation. The expression of ABI3, ABI4 and ABI5, which encode the crucial transcription factors during late maturation, was downregulated by more than 20-fold, and their promoters exhibited a high level of methylation already at the late germination stage. Thus, although ABA remains important, other regulators seems to be involved in the transition from seed to seedling.

CXCL14 is one of the most evolutionarily conserved members of the chemokine family and is constitutionally expressed in multiple organs, suggesting that it is involved in the homeostasis maintenance of the system. CXCL14 is highly expressed in colon epithelial cells and shows obvious gene silencing in clinical colon cancer samples, suggesting that its silencing is related to the immune escape of cancer cells. In this paper, we analyzed the expression profiles of multiple human clinical colon cancer datasets and mouse colon cancer models to reveal the variation trend of CXCL14 expression during colitis, colon polyps, primary colon cancer, and liver metastases. The relationship between CXCL14 gene silencing and promoter hypermethylation was revealed through the colorectal carcinoma methylation database. The results suggest that CXCL14 is a tumor suppressor gene in colorectal carcinoma, which is activated first and then silenced during the process of tumor occurrence and deterioration. Promoter hypermethylation is the main cause of CXCL14 silencing. The methylation level of CXCL14 is correlated with the anatomic site of tumor occurrence and positively correlated with patient age, and associated with prognosis. Reversing the hypermethylation of CXCL14 may be an epigenetic therapy for colon cancer.

Limited studies have shown that exposure to arsenic is associated with serum vitamin D levels, but the results are still inconsistent. A cross-sectional study of 762 participants was conducted in Wenshui Country, Shanxi Province, which was identified as an area of water-borne arsenicosis. The results showed positive relationship between arsenic species (iAs, MMA, DMA) and serum 25(OH)D. Binary logistic regression analysis showed that the significant increases of 0.4% and 0.6% in the risk of vitamin D excess for every 1-unit increment in the Box-Cox transformed urinary tAs and DMA, respectively. After stratifying populations based on arsenic methylation metabolic capacity, each one-unit increase in the Box-Cox transformed tAs level was associated with increases of 0.064 (95%CI: 0.032 to 0.096) in serum 25(OH)D in the populations with iAs% above the median. In the populations with skin hyperkeratosis, urinary iAs was positively associated with serum 25(OH)D (β=0.592, 95%CI: 0.041 to 1.143). Overall, our findings support the positive relationship between urinary arsenic and serum 25(OH)D.

Fibrosis represents a process characterized by excessive deposition of extracellular matrix (ECM) proteins. It often represents the evolution of pathological conditions, causes organ failure, and can, in extreme cases, compromises the functionality of the organs to the point of causing death. In recent years, considerable efforts have been made to understand the molecular mechanisms underlying fibrotic evolution and to identify possible therapeutic strategies. Great interest has been aroused by the discovery of a molecular association between epithelial to mesenchymal plasticity (EMP), in particular epithelial to mesenchymal transition (EMT), and fibrogenesis, which has led to the identification of complex molecular mechanisms closely interconnected with each other, which could explain EMT-dependent fibrosis. However, the result remains unsatisfactory from a therapeutic point of view. In recent years, advances in epigenetics, which is based on chromatin remodeling through various histone modifications or through the intervention of non-coding RNAs (ncRNAs), have provided more information on the fibrotic process, and this could represent a promising path forward for the identification of innovative therapeutic strategies for organ fibrosis. In this review, we summarize current research on epigenetic mechanisms involved in organ fibrosis, with a focus on epigenetic regulation of EMP/EMT-dependent fibrosis.

This study introduces the MuhdoAge clock, a novel saliva-based epigenetic clock, designed to predict biological age with strong correlations in a healthy, disease-free cohort. Leveraging a comprehensive dataset from Muhdo Health, this research analyses saliva samples utilising the Illumina MethylationEPIC array. Through robust statistical methods, 237 significant CpG sites were identified that correlate with age-related methylation changes, exhibiting a coefficient of determination (R²) of 0.652 after outlier removal, with tiered algorithmic design improving this further to 0.726 in a new dataset that combined pathologic and healthy individuals (n=2682). Comparatively, the MuhdoAge clock was evaluated against other known epigenetic clocks, demonstrating high precision in predicting biological age within healthy individuals (R² = 0.878, n=1844), emphasising its potential utility in non-invasive, large-scale applications. The clock shows promise for integration into public health strategies for monitoring and potentially mitigating age-related decline, facilitated by its ease of use and accessibility through saliva sampling. Furthermore, this study highlights the impact of lifestyle and environmental factors on biological ageing, highlighting the importance of personalised health interventions. Future research is to focus on longitudinal studies to validate these findings and explore the mechanisms underlying epigenetic age acceleration.

We conducted a pilot study to analyze the differential methylation status of 20 primary acinar adenocarcinomas of the lungs. These adenocarcinomas had to be wild type in mutation analysis and had either high (TPS>50%; n=10) or low (TPS<1%; n=10) PD-L1 status to be integrated into our study. To examine the methylation of 866,895 specific sites, we utilized the Illumina Infinium EPIC bead chip array. Both hypermethylation and hypomethylation play significant roles in tumor development, progression, and metastasis. They also impact the formation of the tumor microenvironment, which plays a decisive role in tumor differentiation, epigenetics, dissemination, and immune evasion. The gained methylation patterns were correlated with PD-L1 expression. Our analysis has identified distinct methylation patterns in lung adenocarcinomas with high and low PD-L1 expression. After analyzing the correlation between methylation results of genes and promoters with their pathobiology, we found that tumors with high expression of PD-L1 tend to exhibit oncogenic effects through hypermethylation. On the other hand, tumors with low PD-L1 expression show loss of their suppressor functions through hypomethylation. The suppressor functions of hypermethylated genes and promoters are ineffective compared to simultaneously activated dominant oncogenic mechanisms. The tumor microenvironment supports tumor growth in both groups.

The epigenetic mechanism of DNA methylation is essential for regulating gene expression and adaptation in plants, especially when exposed to various environmental stressors such as drought, heat, and nutrient availability. The impact of these stressors can lead to alterations in DNA methylation patterns and gene expression, which this study aims to investigate. Specifically, we are interested in understanding how DNA methylation plays a role in controlling the expression of stress-response genes, as well as genes involved in plant growth and development. To accomplish this, we are analyzing the changes in DNA methylation patterns and gene expression in response to different stressors like drought and heat. Our research findings suggest that DNA methylation is a vital regulator of plant adaptation to environmental stress, and we hope to gain further insight into these mechanisms by identifying genes that exhibit differential expression in response to stress and analyzing their DNA methylation status. This study offers valuable insights into the development of crops that can thrive under changing climate conditions.

Histone post-translational modification is one of the main mechanisms of epigenetic regulation, which plays a crucial role in the control of gene expression and various biological processes. However, whether or not it affects fungal virulence is not clear in Sclerotinia sclerotiorum. In this study, we identified and cloned the histone methyltransferase Defective in methylation 5 (Dim5) in S. sclerotiorum, which encodes a protein containing a typical SET domain. SsDim5 was found to be dynamically expressed during infection. Knockout experiment demonstrated that deletion of SsDim5 reduced the virulence in Ssdim5-1/Ssdim5-2 mutant strains, accompanied by a significant decrease in H3K9 trimethylation levels. Transcriptomic analysis further revealed the downregulation of genes associated with mycotoxins biosynthesis in SsDim5 deletion mutants. Additionally, the absence of SsDim5 affected the fungus's response to oxidative and osmotic, as well as cellular integrity. Together, our results indicate that the H3K9 methyltransferase SsDim5 is essential for H3K9 trimethylation, which regulating fungal virulence to host plants through impacting on mycotoxins biosynthesis, and the response to environmental stresses in S. sclerotiorum.

The European white birch, scientifically known as Betula pendula, and its variant, B. pendula 'Dalecarlica' are characterized by a serrated leaf margin that enhances their aesthetic appeal. However, the lobed leaf trait can undergo random and spontaneous reversion to the typical ovoid or cordate shape during asexual reproduction. Investigating and elucidating the molecular mechanisms underlying this unpredictable reversion mutation is essential for comprehending the birch leaf development process. In this research, we employed a non-lobed-leaf mutant derived from a lobed-leaf birch clone during plant tissue culture. We adopted a multi-omics approach, including whole-genome resequencing, transcriptome sequencing, and methylation profiling, to analyze and compare genomic variations and gene expression modifications. The study revealed that the 24 variant genes affected by 1464 SNP/InDel sites in the genome of the non-lobed-leaf mutant are not associated with leaf development. While the overall methylation level in the mutant's genome closely resembles that of the serrated-leaf birch, ten genes exhibit differential methylation accompanied by differential expression. Transcriptome sequencing demonstrated that the differentially downregulated genes in the mutant are significantly enriched in the GO:0009733 (response to auxin) and GO:0009734 (auxin-activated signaling) pathways. Validation through McrBC-PCR and qRT-PCR confirmed differential methylation and expression of BpIAA9 in the reversion mutant. The elevated methylation level in the BpIAA9 promoter leads to reduced expression, resulting in changes in the expression of auxin-responsive genes. This, in turn, leads to a transcriptional downregulation enrichment effect in auxin-related pathways in the reversion mutant, ultimately inhibiting the regulation of leaf veins by auxin during their development.

Diffuse midline gliomas are among the deadliest human cancers and have had little progress in treatment in the last 50 years. Cell cultures of these tumors have been developed recently, but it is unknown the degree to which such cultures retain the characteristics of the source tumors. DNA methylation profiling offers a powerful tool to look at genome-wide epigenetic changes that are biologically meaningful and can help assess the similarity of cultured tumor cells to their in vivo progenitors. Paraffinized diagnostic tissue from three diffuse intrinsic pontine gliomas with H3 K27M mutations was compared with subsequent passages of neurosphere cell cultures from those tumors. Each cell line was passaged 3-4 times and analyzed with DNA methylation arrays and standard algorithms that provided comparison of diagnostic classification and cluster analysis. All samples tested maintained high classifier scores and clustered within the reference group of H3 K27M-mutant diffuse midline gliomas. There was a gain of 1q in all cell lines, with two cell lines initially manifesting the gain of 1q only during culture. In vitro cell cultures of H3 K27M-mutant gliomas maintain high degrees of similarity in DNA methylation profiles to their source tumor, confirming their fidelity even with some chromosomal changes.

Abstract: Objectives: To establish the expression profile of N6-methyladenosine(m6A) modifications in the hippocampus of mice with diabetic cognitive impairment (DCI) and elucidate the potential regulatory mechanism. Methods: A DCI model was established by feeding a high-fat diet to C57BL/6J mice. m6A and RNA sequencing was conducted to profile the m6A-tagged transcripts in the hippocampus. Results: Methylated RNA immunoprecipitation with next-generation sequencing and RNA sequencing analyses yielded differentially m6A-modified and expressed genes in the hippocampus of DCI mice, which were enriched in pathways involving synaptic transmission and axonal guidance. Mechanistic analyses revealed a remarkable change in m6A modification levels through alteration of the mRNA expression of m6A methyltransferases (METTL3 and METTL14) and demethylase (FTO) in the hippocampus of DCI mice. Conclusions: We identified a co-mediated specific RNA regulatory strategy that broadens the epigenetic regulatory mechanism of RNA-induced neurodegenerative disorders associated with metabolic and endocrine diseases.

Understanding the molecular mechanism whereby an environmental chemical causes a disease is important for downstream purposes. In this study, an analytical workflow was designed to combine several publicly available datasets in order to identify CpG sites and genes that mediate the impact of exposure to environmental chemicals on cardiometabolic traits. Organophosphate and prenatal lead exposure were previously reported to change methylation level at the cg23627948 site. I found as cg23627948 site becomes methylated, the expression of GNA12 gene decreases and this leads to higher body fat percentage. Prenatal perfluorooctane sulfonate expo-sure was reported to increase the methylation level at cg21153102 site. The outcome of analyses revealed higher methylation at this site contributes to higher diastolic blood by changing the expression of CHP1 and GCHFR genes. Furthermore, HKR1 mediates the impact of B12 supple-mentation-cg05280698 hypermethylation on higher kidney function; while, CTDNEP1 mediates the impact of air pollution-cg03186999 hypomethylation on higher systolic blood pressure. This study reports CpG sites and genes that mediate the impact of environmental chemicals on cardiometabolic traits and describes a framework to investigate the underlying molecular paths using publicly available data.

Mutations affecting codon 172 of the isocitrate dehydrogenase 2 (IDH2) gene define a subgroup of sinonasal undifferentiated carcinomas (SNUCs) with a relatively favorable prognosis and a globally hypermethylated phenotype. They are also recurrent (along with IDH1 mutations) in gliomas, acute myeloid leukemia, and intrahepatic cholangiocarcinoma. Commonly reported mutations, all associated with aberrant IDH2 enzymatic activity, include R172S, R172T, R172G, and R172M. We present a case of SNUC with a never-before-described IDH2 mutation, R172A. Our report compares the methylation pattern of our sample to other cases from the GEO database. Hierarchical clustering suggests a strong association between our sample and other IDH-mutant SNUCs and a clear distinction between sino-nasal normal tissues and tumors. Principal component analysis (PCA), using 100 principal components explaining 94.5% of the variance, shows the position of our sample within 1.02 standard deviation of the other IDH-mutant SNUCs. Molecular modeling analysis of the IDH2 R172A versus other R172 variants provides a structural explanation to how they affect the protein active site. Our findings thus suggest that the R172A mutation in IDH2 confers a gain of function similar to other R172 mutations in IDH2, resulting in a similar hypermethylated profile.