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:Using the single-cell sequencing technology, the authors aim to make a construction of a single-cell cell atlas of young and old pituitary cells. Moreover, the sorted Ai6+ cells from pituitary of Igha-Cre; Ai6 were also analyzed by single-cell sequencing.