Project description:Transcriptional Profile of Aging in C. elegans Whole-genome analysis of gene expression during chronological aging of the worm provides a rich database of age-specific changes in gene expression and represents one way to distinguish among these models. Using a rigorous statistical model with multiple replicates, we find that a relatively small number of genes (only 164) show statistically significant changes in transcript levels as aging occurs (<1% of the genome). Expression of heat shock proteins decreases, while expression of certain transposases increases in older worms, and these findings are consistent with a higher mortality risk due to a failure in homeostenosis and destabilization of the genome in older animals. Finally, a specific subset of genes is coordinately altered both during chronological aging and in the transition from the reproductive form to the dauer, demonstrating a mechanistic overlap in aging between these two processes. Groups of assays that are related as part of a time series. Age: Age of organism Computed
Project description:Transcriptional Profile of Aging in C. elegans Whole-genome analysis of gene expression during chronological aging of the worm provides a rich database of age-specific changes in gene expression and represents one way to distinguish among these models. Using a rigorous statistical model with multiple replicates, we find that a relatively small number of genes (only 164) show statistically significant changes in transcript levels as aging occurs (<1% of the genome). Expression of heat shock proteins decreases, while expression of certain transposases increases in older worms, and these findings are consistent with a higher mortality risk due to a failure in homeostenosis and destabilization of the genome in older animals. Finally, a specific subset of genes is coordinately altered both during chronological aging and in the transition from the reproductive form to the dauer, demonstrating a mechanistic overlap in aging between these two processes. Groups of assays that are related as part of a time series. Age: Age of organism Keywords: time_series_design
Project description:Hematopoietic stem cells (HSCs) and their progeny sustain lifetime hematopoiesis. Aging alters HSC function, number, and composition and increases risk of hematological malignancies, but how these changes occur in HSCs remains unclear. Signaling via p38MAPK has been proposed as a candidate mechanism underlying induction of HSC aging. Here, using genetic models of both chronological and premature aging, we describe a multimodal role for p38α, the major p38MAPK isozyme in hematopoiesis, in HSC aging. We report that p38α regulates differentiation bias and sustains transplantation capacity of HSCs in the early phase of chronological aging (from young to 1-year-old). However, p38α decreased HSC transplantation capacity in the late progression phase of chronological aging (from 1- to 2-years-old). Furthermore, co-deletion of p38α in mice deficient in Ataxia-telangiectasia mutated (Atm), a model of premature aging, exacerbated aging-related HSC phenotypes seen in Atm single mutant mice. Mechanistically, p38α makes a positive contribution to inflammation during the late phase aging, resulting in defects in 2-year-old HSCs. Overall, we propose multiple functions of p38MAPK, which both promotes and suppresses HSC aging context-dependently.
Project description:Hematopoietic stem cells (HSCs) and their progeny sustain lifetime hematopoiesis. Aging alters HSC function, number, and composition and increases risk of hematological malignancies, but how these changes occur in HSCs remains unclear. Signaling via p38MAPK has been proposed as a candidate mechanism underlying induction of HSC aging. Here, using genetic models of both chronological and premature aging, we describe a multimodal role for p38α, the major p38MAPK isozyme in hematopoiesis, in HSC aging. We report that p38α regulates differentiation bias and sustains transplantation capacity of HSCs in the early phase of chronological aging (from young to 1-year-old). However, p38α decreased HSC transplantation capacity in the late progression phase of chronological aging (from 1- to 2-years-old). Furthermore, co-deletion of p38α in mice deficient in Ataxia-telangiectasia mutated (Atm), a model of premature aging, exacerbated aging-related HSC phenotypes seen in Atm single mutant mice. Mechanistically, p38α makes a positive contribution to inflammation during the late phase aging, resulting in defects in 2-year-old HSCs. Overall, we propose multiple functions of p38MAPK, which both promotes and suppresses HSC aging context-dependently.
Project description:Genome-wide DNA methylation profiling of colon and ileal biopsies, blood samples from people living with HIV on ART and their matched HIV-negative counterparts. Despite having similar chronological ages, PWH on ART exhibit accelerated biological aging in the colon, ileum, and blood, as measured by various epigenetic aging clocks, compared to HIV-negative controls. Investigating the relationship between microbial translocation and biological aging, PWH on ART had decreased levels of tight junction proteins in the colon and ileum, along with increased microbial translocation.
Project description:The age-related loss of skeletal muscle mass and function (sarcopenia) is one of the most dramatic changes affecting the human body. A clear understanding of the mechanisms involved is thus of paramount importance in ensuring quality of life in the old age. Most previous studies of sarcopenia in human investigated chronological aging, as they relied on comparisons between young and old subjects. Notably, no previous study has taken into consideration inter-individual differences (biological aging) in prevalence of sarcopenia. To obtain an integrative view of muscle biological aging our project uses a single biopsy from 72 well-phenotyped 80 years healthy subjects with different muscle loss/gain (PROOF cohort), to provide an extended characterization of the muscle tissue, including microstructural and omic analyses.
Project description:Background: Liquid biopsies analyzing cell-free DNA methylation in plasma offer a non-invasive diagnostic for diseases, with aging biomarker potential underexplored. Methods: Utilizing enzymatic methyl-seq (EM-seq), this study assessed cfDNA methylation patterns in aging with blood from 35 healthy individuals. Results: It found aging signatures, including higher cfDNA levels and variations in fragment sizes, plus over 2 million age-related differentially methylated CpG sites. A biological age predictive model based on 41 CpG sites showed a strong correlation with chronological age, verified by two datasets. Age-specific epigenetic shifts linked to inflammation were revealed through differentially methylated regions profiling and Olink proteomics. Conclusion: These findings indicate cfDNA methylation as a potential biomarker for aging, and it might exacerbate immunoinflammatory reactivity in older individuals.
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 fiberM-bM-^@M-^Ys 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 have developed an isolation protocol to selectively enrich SCs by FACS from adult mice and applied the ChIP-seq technology to obtain H3K4me3, H3K27me3 and H3K36me3 from quiescent and activated SCs from young mice and from quiescent SCs from old mice. Our analysis aims to understand the chromatin features underlying stem cell properties such as quiecence and lineage-potency, and to understand how the chromatin structure 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 and processed for ChIP-seq.
Project description:Age-related physiological decline emerges at different chronological ages across individuals. We compared mice that exhibited early or delayed hematopoietic aging at the same chronological age by scRNA-seq.