Project description:The aging of mammalian epigenomes fundamentally alters cellular functions, implicating organismal fitness and disease risk. However, the studies of this process typically use mouse models in the laboratory environment and neglect the impact of variation in social, physical, microbial, and other aspects of the living environment. We examined the aging differences between lab mice and “re-wilded” mice, which are C57BL6/J mice reintroduced into a controlled field environment with enhanced realism. Systematic analysis of age-associated methylation dynamics in the liver tissues suggests a genomic region-conditioned, faster epigenetic aging rate in field mice than in lab mice, implicating a 3D genome conformation change. The predicted age of lab mice by epigenetic clocks is closer to their actual age than that of field mice. These observations underscore the overlooked role of the social and physical environment in epigenetic aging.
Project description:This SuperSeries is composed of the following subset Series: GSE25323: Biological Aging and Circadian Mechanisms in Murine Brown Adipose Tissue, Inguinal White Adipose Tissue, and Liver (Nov 2009 dataset) GSE25324: Biological Aging and Circadian Mechanisms in Murine Brown Adipose Tissue, Inguinal White Adipose Tissue, and Liver (Jan 2010 dataset) Refer to individual Series
Project description:This is the proteomics component of a multi-omics analysis of the aging murine retina. Age is a critical risk factor for vision-threatening retinopathies. Susceptibility to age-related retinal neurodegeneration is genetically influenced, however, no studies have addressed molecular retinal aging signatures across genetically diverse populations. Here, we profile retinal proteomics in an array of genetically diverse mice with age. Proteomics were employed to profile retinal aging signatures in C57BL/6J (B6), 129S1/SvImJ, NZO/HlLtJ (NZO), WSB/EiJ (WSB), CAST/EiJ, PWK/PhJ, NOD/ShiLtJ, A/J, and BALB/cJ mouse strains at 4, 12, and 18M. These data were collated into a publicly available resource.
Project description:Living in adverse neighborhood environments has been linked to risk of aging-related diseases and mortality; however, the biological mechanisms explaining this observation remain poorly understood. DNA methylation (DNAm), a proposed mechanism and biomarker of biological aging responsive to environmental stressors, offers promising insight into potential molecular pathways. We examined associations between three neighborhood social environment measures (poverty, quality, and social cohesion) and three epigenetic clocks (Horvath, Hannum, and PhenoAge) using data from the Detroit Neighborhood Health Study (n=158). Using linear regression models, we evaluated associations in the total sample and stratified by sex and social cohesion. Neighborhood quality was associated with accelerated DNAm aging for Horvath age acceleration (β = 1.8; 95% CI: 0.4, 3.1), Hannum age acceleration (β = 1.7; 95% CI: 0.4, 3.0), and PhenoAge acceleration (β = 2.1; 95% CI: 0.4, 3.8). In models stratified on social cohesion, associations of neighborhood poverty and quality with accelerated DNAm aging remained elevated for residents living in neighborhoods with lower social cohesion, but were null for those living in neighborhoods with higher social cohesion. Our study suggests that living in adverse neighborhood environments can speed up epigenetic aging, while positive neighborhood attributes may buffer effects.
Project description:Skeletal muscle is a post-mitotic tissue that exhibits an extremely low turnover in the absence of disease or injury. At the same time, muscle possesses remarkable regenerative capacity mediated by satellite cells (SCs) that reside in close association with individual myofibers, underneath the fiber’s basal lamina. Consistent with the low turnover of the muscle, SCs in adult animals are mitotically quiescent and therefore provide an excellent model to study stem cell quiescence. As an organism grows older, the resident stem cells are exposed to a deteriorating environment and experience chronological aging. In stem cells with high turnover, the effects of chronological aging are superimposed upon the effects of the replicative aging that results from DNA replication and cell division. On the contrary, SCs experience minimal replicative aging due to their low turnover. They are thus a good model to study the consequence of chronological aging of quiescent stem cells. We performed microarray analysis of quiescent and activated SCs from both young and aged mice to understand the global gene expression profile underlying stem cell properties such as quiecence and self-renewal, and to understand how the transcriptome of a quiescent stem cell pouplation changes with age. VCAM+/CD31-/CD45-/Sca1- quiescent satellite cells (QSCs) were isolated by FACS from hindlimb muscle of uninjured 2-3- or 22-24-month old mice. Activated satellite cells (ASCs) were isolated from hindlimb muscles of BaCl2-injured mice of the same age 36, 60 and 84 hours after injury using the same cell surface marker combination. YFP-expressing cells were isolated from 2-3-month old Pax7CreER/+; ROSA26eYFP/+ mice in which satellite cells are labeled geneticall by YFP expression. Total RNA was extracted from cells with the Trizol reagent according to manufacturer's instructions. RNA was then processed and assayed with Affymetrix Mouse Gene 1.0 ST arrays.