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1.
Circulation ; 140(8): 645-657, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31424985

RESUMO

BACKGROUND: DNA methylation is implicated in coronary heart disease (CHD), but current evidence is based on small, cross-sectional studies. We examined blood DNA methylation in relation to incident CHD across multiple prospective cohorts. METHODS: Nine population-based cohorts from the United States and Europe profiled epigenome-wide blood leukocyte DNA methylation using the Illumina Infinium 450k microarray, and prospectively ascertained CHD events including coronary insufficiency/unstable angina, recognized myocardial infarction, coronary revascularization, and coronary death. Cohorts conducted race-specific analyses adjusted for age, sex, smoking, education, body mass index, blood cell type proportions, and technical variables. We conducted fixed-effect meta-analyses across cohorts. RESULTS: Among 11 461 individuals (mean age 64 years, 67% women, 35% African American) free of CHD at baseline, 1895 developed CHD during a mean follow-up of 11.2 years. Methylation levels at 52 CpG (cytosine-phosphate-guanine) sites were associated with incident CHD or myocardial infarction (false discovery rate<0.05). These CpGs map to genes with key roles in calcium regulation (ATP2B2, CASR, GUCA1B, HPCAL1), and genes identified in genome- and epigenome-wide studies of serum calcium (CASR), serum calcium-related risk of CHD (CASR), coronary artery calcified plaque (PTPRN2), and kidney function (CDH23, HPCAL1), among others. Mendelian randomization analyses supported a causal effect of DNA methylation on incident CHD; these CpGs map to active regulatory regions proximal to long non-coding RNA transcripts. CONCLUSION: Methylation of blood-derived DNA is associated with risk of future CHD across diverse populations and may serve as an informative tool for gaining further insight on the development of CHD.

2.
Aging (Albany NY) ; 8(9): 1844-1865, 2016 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-27690265

RESUMO

Estimates of biological age based on DNA methylation patterns, often referred to as "epigenetic age", "DNAm age", have been shown to be robust biomarkers of age in humans. We previously demonstrated that independent of chronological age, epigenetic age assessed in blood predicted all-cause mortality in four human cohorts. Here, we expanded our original observation to 13 different cohorts for a total sample size of 13,089 individuals, including three racial/ethnic groups. In addition, we examined whether incorporating information on blood cell composition into the epigenetic age metrics improves their predictive power for mortality. All considered measures of epigenetic age acceleration were predictive of mortality (p≤8.2x10-9), independent of chronological age, even after adjusting for additional risk factors (p<5.4x10-4), and within the racial/ethnic groups that we examined (non-Hispanic whites, Hispanics, African Americans). Epigenetic age estimates that incorporated information on blood cell composition led to the smallest p-values for time to death (p=7.5x10-43). Overall, this study a) strengthens the evidence that epigenetic age predicts all-cause mortality above and beyond chronological age and traditional risk factors, and b) demonstrates that epigenetic age estimates that incorporate information on blood cell counts lead to highly significant associations with all-cause mortality.


Assuntos
Envelhecimento/fisiologia , Metilação de DNA/fisiologia , Envelhecimento/genética , Grupos de Populações Continentais , Epigênese Genética , Feminino , Humanos , Modelos Logísticos , Masculino , Mortalidade , Fatores de Risco , Análise de Sobrevida , Subpopulações de Linfócitos T
3.
Sci Rep ; 5: 17911, 2015 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-26648411

RESUMO

DNA methylation is an epigenetic modification with important functions in development. Large-scale loss of DNA methylation is a hallmark of cancer. Recent work has identified large genomic blocks of hypomethylation associated with cancer, EBV transformation and replicative senescence, all of which change the proportion of actively proliferating cells within the population measured. We asked if replication or cell-cycle arrest affects the global levels of methylation or leads to hypomethylated blocks as observed in other settings. We used fluorescence activated cell sorting to isolate primary dermal fibroblasts in G0, G1 and G2 based on DNA content and Ki67 staining. We additionally examined G0 cells arrested by contact inhibition for one week to determine the effects of extended arrest. We analyzed genome wide DNA methylation from sorted cells using whole genome bisulfite sequencing. This analysis demonstrated no global changes or large-scale hypomethylated blocks in any of the examined cell cycle phases, indicating that global levels of methylation are stable with replication and arrest.


Assuntos
Pontos de Checagem do Ciclo Celular , Metilação de DNA , Replicação do DNA , Animais , Senescência Celular/genética , Ilhas de CpG , Epigênese Genética , Epigenômica , Fibroblastos , Genoma , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Antígeno Ki-67/metabolismo
4.
Genome Biol ; 16: 80, 2015 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-25886480

RESUMO

BACKGROUND: Aging and sun exposure are the leading causes of skin cancer. It has been shown that epigenetic changes, such as DNA methylation, are well established mechanisms for cancer, and also have emerging roles in aging and common disease. Here, we directly ask whether DNA methylation is altered following skin aging and/or chronic sun exposure in humans. RESULTS: We compare epidermis and dermis of both sun-protected and sun-exposed skin derived from younger subjects (under 35 years old) and older subjects (over 60 years old), using the Infinium HumanMethylation450 array and whole genome bisulfite sequencing. We observe large blocks of the genome that are hypomethylated in older, sun-exposed epidermal samples, with the degree of hypomethylation associated with clinical measures of photo-aging. We replicate these findings using whole genome bisulfite sequencing, comparing epidermis from an additional set of younger and older subjects. These blocks largely overlap known hypomethylated blocks in colon cancer and we observe that these same regions are similarly hypomethylated in squamous cell carcinoma samples. CONCLUSIONS: These data implicate large scale epigenomic change in mediating the effects of environmental damage with photo-aging.


Assuntos
Envelhecimento/genética , Epiderme/metabolismo , Genômica , Envelhecimento da Pele/efeitos da radiação , Luz Solar/efeitos adversos , Adulto , Idoso , Metilação de DNA/efeitos da radiação , Epigênese Genética , Epigenômica , Feminino , Biblioteca Gênica , Voluntários Saudáveis , Humanos , Masculino , Análise de Sequência de DNA , Envelhecimento da Pele/fisiologia , Neoplasias Cutâneas/etiologia
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