Project description:Aging is a multifactorial process with significant functional alterations of the human body including endocrinal systems which control the whole-body physiology and metabolism. In this vein, aging-induced decline of endocrine function are associated with multiple physiological and metabolic diseases. However, aging-associated molecular shifts in the pituitary gland, the central organ of the endocrine system, have not been dissected systemically. In this study, we conducted single-cell transcriptomic analysis of the anterior pituitary gland by comparing old and young male mice. Single-cell transcriptomics not only increased the resolution for clustering of various cell types in the pituitary gland, but also enabled detailed analysis of differential expression and intercellular communication caused by aging. In summary, our study constructed the first single-cell transcriptomic atlas of pituitary aging and identified associated features of in a single-cell level, providing resources to develop novel potential therapeutic targets for aging-associated endocrine dysfunction.
Project description:Purpose: Molecular mechanisms of penile corpus cavernosum aging and male age-related erectile dysfunction (ED) remain unclear. Here we profiled young and old rat penile corpus cavernousm by single-cell RNA sequencing (scRNA-seq). Methods:To map the single-cell transcriptomic landscape of penile corpus cavernosum during aging, we performed uniform manifold approximation and projection (UMAP), differential gene expression analysis (DGEs), pseudotime analysis and single-cell entropy algorithm to dissect cellular composition and transcriptional heterogeneity. For validation analysis, we further performed immunofluorescence studies on key molecules involved during penile corpus cavernosum aging. Results: After stringent filtering,transcriptomes of 14,879 single cells (8,557 young and 6,322 old) derived from penile corpus cavernosum of 5 young (3 months) and 5 old (23 months) rats were analyzed subsequently. Clustering analysis of cell-type specific gene expression identified 19 cell types, such as smooth muscle cells, endothelial cells, fibroblasts,myofibroblasts and immune cells.Transcriptomic analyses revealed that transcriptional alterations across all cell types exhibited distinct properties rather than universally consistent. DGEs analysis demonstrated that genes related to extracellular matrix organization were highly expressed. Among these cell types, fibroblasts showed apparent heterogeneities. By performing pseudotime and single-cell entropy analysis on fibroblasts, we observed the age-associated decrease of entropy, and aged fibroblasts were found to adopt senescent secretory phenotype, as evidenced by the high expression of genes associated with the senescence-associated secretory phenotype (SASP). Since eliminating senescent cells or SASP were demonstrated to improve health and life span, we further investigated the distinct senescence-related gene expression signatures across all cell types during aging. Conclusions: We plotted a cellular atlas of penile corpus cavernosum, and revealed the molecular alterations of aging cells, especially fibroblasts. Our work will deepen the understanding of the heterogeneity among certain cell types during penile corpus cavernosum aging and provide novel entry points for the age-associated ED treatment.
Project description:Aging-related degeneration of pancreatic islet cells contributes to impaired glucose tolerance and diabetes. Endocrine cells age heterogeneously, complicating the effort to unravel the molecular drives underlying endocrine aging. To overcome these obstacles, we undertook single-cell RNA sequencing of pancreatic islet cells obtained from young and aged non-diabetic cynomolgus monkeys. Despite sex differences and increased single-cell level transcriptional variations, aged β-cells showed increased unfolded protein response (UPR) along with the accumulation of protein aggregates. We observed transcriptomic dysregulation of UPR components linked to canonical ATF6 and IRE1 signaling, comprising adaptive UPR during pancreatic aging. Notably, we found age-related β-cell-specific upregulation of HSP90B1, an ER-located chaperone, impeded high glucose-induced insulin secretion. Our work decodes aging-associated transcriptomic changes that underlie pancreatic islet functional decay at the single-cell resolution and indicates that targeting UPR components may prevent loss of proteostasis, suggesting an avenue for therapies to delay β-cell aging and prevent aging-related diabetes.
Project description:Molecular mechanisms of ovarian aging and female age-related fertility decline remain unclear. We surveyed the single-cell transcriptomic landscape of ovaries from young and aged non-human primates (NHPs) and identified seven ovarian cell types with distinct gene expression signatures, including oocyte and six types of ovarian somatic cells. In-depth dissection of gene expression dynamics of oocytes revealed four subtypes at sequential and stepwise developmental stages. Further analysis of cell type-specific aging-associated transcriptional changes uncovered the disturbance of antioxidant signaling specific to early-stage oocytes and granulosa cells, indicative of oxidative damage as a crucial factor in ovarian functional decline with age. Additionally, inactivated antioxidative pathways, increased reactive oxygen species and apoptosis were observed in granulosa cells from aged women. This study provides comprehensive understanding of the cell type-specific mechanisms underlying primate ovarian aging at single-cell resolution, revealing new diagnostic biomarkers and potential therapeutic targets for age-related human ovarian disorders.
Project description:Aging is accompanied by the functional decline of all tissues, but it is still largely unknown how aging impacts different tissues in a cell type-specific manner. Here, we present the Aging Fly Cell Atlas (AFCA) that includes single-nucleus transcriptomes of the entire Drosophila head and body from both males and females at four different ages. We characterize 162 distinct cell types and present an in-depth analysis of cell type-specific aging features, including changes of cell composition, gene expression, number of expressed genes, transcriptome noise, and cell identity. By combining all aging features, including aging clock models predicting a cell’s age, we find cell-type specific aging patterns. Adipose tissues showed the highest aging score, followed by two cell types from the reproductive system. This transcriptomic atlas provides a valuable resource for the community to study fundamental principles of aging in complex organisms.
Project description:Skin is the largest barrier organ with complex structure and function. We investigated the transcriptional dynamics of pig skin during development and aging at single-cell resolution. Using single-cell RNA sequencing, we profiled the transcriptomes of 443,529 skin cells derived from 30 individuals of 10 developmental time points staged between 56 days of gestation and 7 years old. Our analysis identified the dynamic changes in the cellular transcriptional profile of eight skin cell types at different developmental stages, exhibiting time-dependent skin cell heterogeneity.
Project description:Aging promotes lung function decline and susceptibility to chronic lung diseases, which are the third leading cause of death worldwide. We used single cell transcriptomics and mass spectrometry to quantify changes in cellular activity states of 30 cell types and the tissue proteome from lungs of young and old mice. Aging led to increased transcriptional noise, indicating deregulated epigenetic control. We observed highly distinct effects of aging on cell type level, uncovering increased cholesterol biosynthesis in type-2 pneumocytes and lipofibroblasts as a novel hallmark of lung aging. Proteomic profiling revealed extracellular matrix remodeling in old mice, including increased collagen IV and XVI and decreased Fraser syndrome complex proteins and Collagen XIV. Computational integration of the aging proteome and single cell transcriptomes predicted the cellular source of regulated proteins and created a first unbiased reference of the aging lung. The lung aging atlas can be accessed via an interactive user-friendly webtool at: https://theislab.github.io/LungAgingAtlas