Epigenetics最新文献

Poly-epigenetic scores (PEGS) are surrogate measures that help capture individual-level risk. Understanding how the associations between PEGS and cardiometabolic risk factors vary by demographics and health behaviors is crucial for lowering the burden of cardiometabolic diseases. We used results from established epigenome-wide association studies to construct trait-specific PEGS from whole blood DNA methylation for systolic and diastolic blood pressure (SBP, DBP), body mass index (BMI), C-reactive protein (CRP), high- and low-density lipoprotein cholesterol (HDL-C, LDL-C), triglycerides (TG), and fasting glucose. Overall and race-stratified associations between PEGS and corresponding traits were examined in adults >50 years from the Health and Retirement Study (n = 3,996, mean age = 79.5 years). We investigated how demographics (age, sex, educational attainment) and health behaviors (smoking, alcohol consumption, physical activity) modified these associations. All PEGS were positively associated with their corresponding cardiometabolic traits (p < 0.05), and most associations persisted across all racial/ethnic groups. Associations for BMI, HDL-C, and TG were stronger in younger participants, and BMI and HDL-C associations were stronger in females. The CRP association was stronger among those with a high school degree. Finally, the HDL-C association was stronger among current smokers. These findings support PEGS as robust surrogate measures and suggest the associations may differ among subgroups.

Lung carcinogenesis is causally linked to cigarette smoking, in part by epigenetic changes. We tested whether accumulated epigenetic change in smokers is apparent in bronchial basal cells as cells of origin of squamous cell carcinoma. Using an EM-seq platform covering 53.8 million CpGs (96% of the entire genome) at an average of 7.5 sequencing reads per CpG site at a single base resolution, we evaluated cytology-normal basal cells bronchoscopically brushed from the in situ tobacco smoke-exposed 'bronchial epithelial field' and isolated by short-term primary culture from 54 human subjects. We found that mean methylation was globally lower in ever (former and current) smokers versus never smokers (p = 0.0013) across promoters, CpG shores, exons, introns, 3'-UTRs, and intergenic regions, but not in CpG islands. Among 6mers with dinucleotides flanking CpG, those containing CGCG showed no effect from smoking, while those flanked with TT and AA displayed the strongest effects. At the gene level, smoking-related differences in methylation level were observed in CDKL1, ARTN, EDC3, CYP1B1, FAM131A, and MAGI2. Among candidate cancer genes, smoking reduced the methylation level in KRAS, ROS1, CDKN1A, CHRNB4, and CADM1. We conclude that smoking reduces long-term epigenome-wide methylation in bronchial stem cells, is impacted by the flanking sequence, and persists indefinitely beyond smoking cessation.

Colorectal cancer (CRC) remains an alarming global health concern despite advancements in treatment modalities over recent decades. Among the various factors contributing to CRC, this review emphasizes the critical role of epigenetic mechanisms in its pathogenesis and progression. This review also describes the potential role of natural compounds in altering the epigenetic landscape, focused mainly on DNA methylation, histone modification, and non-coding RNAs. Publications from the previous five years were searched and retrieved using well-known search engines and databases like PubMed, Google Scholar, and ScienceDirect. Keywords like CRC/colorectal cancer, CAC/Colitis associated CRC, inflammasomes, epigenetic modulation, genistein, curcumin, quercetin, resveratrol, anthocyanins, sulforaphane, and epigallocatechin-3-gallate were used in various combinations during the search. These natural compounds predominantly affect pathways such as Wnt/β-catenin, NF-κB, and PI3K/AKT to suppress CRC cell proliferation and oxidative stress and enhance anti-inflammation and apoptosis. However, their clinical use is restricted due to their low bioavailability. However, multiple methods exist to overcome challenges like this, including but not limited to structural modifications, nanoparticle encapsulations, bio-enhancers, and novel advanced delivery systems. These methods improve their potential as supportive therapies that target CRC progression epigenetically with fewer side effects. Current research focuses on enhancing epigenetic targeting to control CRC progression while minimizing side effects, emphasizing improved specificity, bioavailability, and efficacy as standalone or synergistic therapies.

We performed an integrated analysis of genome-wide DNA methylation and expression datasets in normal cells and healthy animals exposed to polyphenols with estrogenic activity (i.e. phytoestrogens). We identified that phytoestrogens target genes linked to disrupted cellular homeostasis, e.g. genes limiting DNA break repair (RNF169) or promoting ribosomal biogenesis (rDNA). Existing evidence suggests that DNA methylation may be governed by sirtuin 1 (SIRT1) deacetylase via interactions with DNA methylating enzymes, specifically DNMT3B. Since SIRT1 was reported to be regulated by phytoestrogens, we test whether phytoestrogens suppress genes related to disrupted homeostasis via SIRT1/DNMT3B-mediated transcriptional silencing. Human MCF10A mammary epithelial cells were treated with phytoestrogens, pterostilbene (PTS) or genistein (GEN), followed by analysis of cell growth, DNA methylation, gene expression, and SIRT1/DNMT3B binding. SIRT1 occupancy at the selected phytoestrogen-target genes, RNF169 and rDNA, was accompanied by consistent promoter hypermethylation and gene downregulation in response to GEN, but not PTS. GEN-mediated hypermethylation and SIRT1 binding were linked to a robust DNMT3B enrichment at RNF169 and rDNA promoters. This was not observed in cells exposed to PTS, suggesting a distinct mechanism of action. Although both SIRT1 and DNMT3B bind to RNF169 and rDNA promoters upon GEN, the two proteins do not co-occupy the regions. Depletion of SIRT1 abolishes GEN-mediated decrease in rDNA expression, suggesting SIRT1-dependent epigenetic suppression of rDNA by GEN. These findings enhance our understanding of the role of SIRT1-DNMT3B interplay in epigenetic mechanisms mediating the impact of phytoestrogens on cell biology and cellular homeostasis.

Gestational epigenetic aging (GEA) is a novel approach for characterizing associations between prenatal exposures and postnatal risks. Psychosocial adversity in pregnancy may influence GEA, but the molecular mechanisms are not well understood. DNA methylation to glucocorticoid regulation and hypothalamic-pituitary-adrenal (HPA) axis genes are implicated but have not been fully examined in association with GEA. This study investigated whether a polyepigenetic glucocorticoid exposure score (PGES) and HPA axis gene (NR3C1, HSD11B2, FKBP5) methylation were associated with GEA, and whether associations were sex-specific. Participants were from a prospective cohort of racial/ethnic diverse and socially disadvantaged pregnant women and infants (n = 200). DNA methylation variables were estimated using umbilical cord blood. PGES was derived with CpGs shown to be sensitive to synthetic dexamethasone exposure. NR3C1, HSD11B2, and FKBP5 methylation was summarized via factor analysis. We found that PGES (β = -1.12, SE = 0.47, p = 0.02) and several NR3C1 and FKBP5 factor scores were associated with decelerated GEA (all p < 0.05). A significant sex interaction was observed for FKBP5 factor score 3 (β = -0.34, SE = 0.15, p = 0.02) suggesting decelerated GEA for males but not females. This study showed that glucocorticoid regulation-related DNA methylation was associated with a decelerated aging phenotype at birth that might indicate a neonatal risk.

Fetal growth restriction (FGR) is associated with perinatal death and adverse birth outcomes, as well as long-term complications, including increased childhood morbidity, abnormal neurodevelopment, and cardio-metabolic diseases in adulthood. Placental epigenetic reprogramming associated with FGR may mediate these long-term outcomes. Placental malaria (PM), characterized by sequestration of Plasmodium falciparum-infected erythrocytes in placental intervillous space, is the leading global cause of FGR, but its impact on placental epigenetics is unknown. We hypothesized that placental methylomic profiling would reveal common and distinct mechanistic pathways of non-malarial and PM-associated FGR. We analyzed placentas from a US cohort with no malaria exposure (n = 12) and a cohort from eastern Uganda, a region with a high prevalence of malaria (n = 12). From each site, 8 cases of FGR and 4 healthy controls were analyzed. PM was diagnosed by placental histopathology. We compared the methylation levels of over 850K CpGs of the placentas using Infinium MethylationEPIC v1 microarray. Non-malarial FGR was associated with 65 differentially methylated CpGs (DMCs), whereas PM-FGR was associated with 133 DMCs, compared to their corresponding controls without FGR. One DMC (cg16389901, located in the promoter region of BMP4) was commonly hypomethylated in both groups. We identified 522 DMCs between non-malarial FGR vs. PM-FGR placentas, independent of differing geographic location or cellular composition. Placentas with PM-associated FGR have distinct methylation profiles compared to placentas with non-malarial FGR, suggesting novel epigenetic reprogramming in response to malaria. Larger cohort studies are needed to determine the distinct long-term health outcomes in PM-associated FGR pregnancies.

The placenta is vital for fetal growth, and its methylation patterns reflect placental function, affecting the fetus and providing insights into disease origins. While cord blood methylation is convenient for assessing the fetal environment, methylation profiles vary by tissue due to variance in cell populations, function, and life stage. As tissue differences extensively contribute to the DNA methylation patterns, using surrogate samples such as cord blood may result in inconsistent findings. In this study, we aim to quantify the correlation of cytosine-phosphate-guanine dinucleotides (CpGs) between paired cord blood and placenta samples. Using the Infinium Human Methylation 450 K BeadChip, we compared methylation patterns in cord blood mononuclear cells (CBMC; n = 54), the maternally-facing side of placental tissue (MP; n = 68), and the fetal-facing side of placental tissue (FP; n = 67). Methylation patterns from the FP (6,021 CpGs) were significantly correlated with CBMC compared to the MP (2,862 CpGs). These CpGs were related to the biological (mitotic cell) process and molecular function (ribonucleoprotein complex binding). Our findings quantified CpG site correlation between cord blood and placenta, providing a valuable reference for future studies on placental health that rely on cord blood methylation in the absence of placental biospecimens.

Sickle cell trait (SCT) is due to heterozygosity for the β-globin sickle cell mutation. SCT recently has been associated with increased risk of various adverse health outcomes. DNA methylation (DNAm) is one potential mechanism by which SCT may impact disease risk. To identify DNAm sites associated with SCT, we conducted an epigenome-wide association (EWAS) meta-analysis using whole blood Illumina EPIC array data available in a total of 3,677 African American participants (including 1,071 with SCT) from the Women's Health Initiative and Jackson Heart Study. We identified 103 differentially methylated CpGs and 119 differentially methylated regions associated with SCT. The strongest signals were hypermethylated cis loci within predicted regulatory elements within or near the β-globin gene cluster on chromosome 11. Beyond the globin locus, SCT-associated DMPs were enriched in genes involved in redox regulation and oxidative stress. We also demonstrate an association of SCT with differences in biological age and epigenetic age acceleration, though the pattern and strength of association differ according to the epigenetic clock used. Specifically, more recent epigenetic clocks that incorporate clinical phenotypes or laboratory biomarkers related to adverse health outcomes are associated with accelerated aging among individuals with SCT compared to African American controls. Our results lay the groundwork for future study of the role of DNAm in biologic aging and related health outcomes among individuals with SCT.

The landscape of PIWI-interacting RNA (piRNA) expression in the heart is poorly understood, particularly regarding sex differences. Altered piRNA expression has been reported in cardiovascular disease (CVD), and although exposure to the metal lead (Pb) is strongly associated with CVD risk, no studies have investigated Pb's effects on cardiac piRNAs. This study aimed to characterize piRNA expression in the murine heart and assess sex-specific effects of human-relevant maternal Pb exposure on adult offspring cardiac piRNA expression. piRNAs were identified from whole mouse hearts using sodium periodate exclusion of small RNA and subsequent sequencing. Control mice expressed 18,956 piRNAs in combined-sex analysis; sex-specific analyses revealed 9,231 piRNAs in female hearts and 5,972 piRNAs in male hearts. Genomic mapping showed 28-41% aligned to introns, while 12-28% mapped to exons. Comparing control and Pb-exposed hearts, we found more potential Pb-induced expression changes in females (847) compared to males (187) (p-value < 0.05 and |logFC| > 1). These piRNAs were significantly enriched near genes involved in biological processes related to heart function and CVD development, including mitochondrial function, energy metabolism, and cardiac muscle structure (FDR < 0.05). Overall, we characterized combined and sex-stratified piRNA expression in both control and Pb-exposed murine hearts. In addition to providing a foundation for sex-specific piRNA expression in the heart, these findings suggest a novel epigenetic mechanism by which developmental Pb exposure may impact CVD risk later in life. Future studies will link these sex-specific molecular changes to Pb-induced alterations in cardiac function.

Skin cutaneous melanoma (SKCM) is an aggressive tumor with a poor prognosis. We developed SKCM-P8, a novel qualitative prognostic biomarker based on the relative methylation orderings of eight pairs of loci. Analysis of a training cohort and two independent validation datasets revealed a significant difference in overall survival between high- and low-risk groups stratified by SKCM-P8 (p < 0.05, log-rank test), with average area under the curve values of 0.83, 0.80, and 0.61, respectively. The differential methylation loci between high- and low-risk patients were enriched in immune-related biological processes and signaling pathways. Furthermore, low-risk patients exhibited higher CD8+ T cells and B levels, while high-risk patients had higher monocytes. The methylation levels of SKCM-P8 were also correlated with immune cell levels, indicating that they can reflect prognosis-related immune information. The low-risk group had a significantly higher mutation burden (p < 0.05, Wilcoxon test), suggesting potential benefits from immune checkpoint inhibitors. Patients stratified by SKCM-P8 displayed differential responses to therapy and immunotherapy (p < 0.05, Wilcoxon test), with low-risk patients showing better sensitivity and response. Furthermore, SKCM-P8 demonstrated super-predictive accuracy compared to six published models. Overall, SKCM-P8 offers a promising tool for predicting prognosis and guiding therapeutic decisions in SKCM.