Project description:Aging is classically conceptualized as an ever-increasing trajectory of damage accumulation and loss of function, leading to increases in morbidity and mortality. However, recent in vitro studies have raised the possibility of age reversal. We characterized several models in which biological age, assessed primarily through analysis of DNA methylation, undergoes reversible changes. Pregnancy is one such example.
Project description:The methylation data were measured from longitudinal blood samples to study the longitudinal change of methylation in association with age.
Project description:Mammary gland development and luminal differentiation occur largely postnatally during puberty and pregnancy. To explore the role of DNA methylation in luminal cell differentiation and pregnancy-induced changes, we determined the genome-wide DNA methylation and gene expression profiles of mammary epithelial stem, luminal progenitor, and mature luminal cells at different reproductive stages. We found that pregnancy had the most significant effects on stem cells, inducing a distinct epigenetic state that remained stable through life. Integrated analysis of gene expression, DNA methylation, and histone modification profiles revealed cell type and reproductive stage-specific changes in molecular signatures. We also identified p27 and TGFβ signaling as key regulators of luminal progenitor cell proliferation based on their expression patterns and by the use of explant cultures. Our results suggest relatively minor changes in DNA methylation during luminal cell differentiation as compared to the significant effects of pregnancy on mammary epithelial stem cells. Mammary glands were collected from mice treated with DNA methylation inhibitor 5-azacytidine (AzaC) and histone deacetylase inhibitor valproic acid (VPA) at non-pregnant and pregnant stages for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Mammary gland development and luminal differentiation occur largely postnatally during puberty and pregnancy. To explore the role of DNA methylation in luminal cell differentiation and pregnancy-induced changes, we determined the genome-wide DNA methylation and gene expression profiles of mammary epithelial stem, luminal progenitor, and mature luminal cells at different reproductive stages. We found that pregnancy had the most significant effects on stem cells, inducing a distinct epigenetic state that remained stable through life. Integrated analysis of gene expression, DNA methylation, and histone modification profiles revealed cell type and reproductive stage-specific changes in molecular signatures. We also identified p27 and TGFβ signaling as key regulators of luminal progenitor cell proliferation based on their expression patterns and by the use of explant cultures. Our results suggest relatively minor changes in DNA methylation during luminal cell differentiation as compared to the significant effects of pregnancy on mammary epithelial stem cells.
Project description:Peripheral blood samples were obtained at baseline and at follow-up visit from 20 participants in the Health, Aging and Body Composition prospective cohort study. Genome-wide CpG methylation was assayed using the Illumina Infinium Human MethylationEPIC (HM850K) microarray. We explored longitudinal changes in CpG methylation from blood leukocytes, and likelihood of a future cancer diagnosis.
Project description:Cardiac surgery and cardiopulmonary bypass induce a substantial immune and inflammatory response, the overactivation of which is associated with significant complications. Longitudinal DNA methylation profiling allows the potential to identify changes in gene regulatory mechanisms that are secondary to surgery and to identify molecular processes that predict and/or cause postoperative complications. In this study, we measure DNA methylation in preoperative and postoperative whole blood samples from 96 patients undergoing cardiac surgery on cardiopulmonary bypass. We identify several loci with statistically significant postoperative changes in methylation. Additionally, two of these loci are associated with new-onset postoperative atrial fibrillation, a significant complication after cardiac surgery. This research establishes that there are statistically significant changes in DNA methylation that occur immediately after cardiac surgery and that these acute alterations in DNA methylation have the granularity to identify processes associated with major postoperative complications.
Project description:This DNA methylation dataset describes epigenomic changes in astrocytes culture in vitro with passaging, in the context of studies examining cellular aging patterns that are conserved in vivo and in vitro. Fetal astrocytes were derived from cerebral cortex. Cells were grown under normoxic conditions and exhaustively passaged until cellular senescence. Longitudinal DNA samples were collected throughout passaging and DNA methylation was measured using the Infinium HumanMethylationEPIC BeadChip. In addition, some samples were sorted by FACS using senescence markers prior to DNA extraction for additional DNA methylation measurements.