GSE168545
Single-Cell Transcriptomic Atlas of Penile Corpus Cavernosum Aging
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. Overall design: Single cell sequencing of cells derived from penile corpus cavernosum of 5 young (3 months) and 5 old (23 months) male Sprague-Dawley rats