Proteomic analysis and miRNA profiling of human testicular endothelial cell-derived exosomes: the potential effects on spermatogenesis

Testicular endothelial cells have been found to play an important role in spermatogenesis and fertility, but their mechanism is obscure. Exosomes released by various cells are recognized as cell–cell communication mediators during the initiation and progression of many diseases. Therefore, the current study aimed to investigate the protein and miRNA components of human testicular endothelial cell-derived exosomes (HTEC-Exos) and to explore their potential effects on spermatogenesis. In this study, HTEC-Exos were first isolated by the ultracentrifugation method, and then identified by nanoparticle tracking analysis, transmission electron microscopy (TEM), and western blotting. The characteristics of HTEC-Exos were examined by liquid chromatography–mass spectrometry and microRNA (miRNA) chip analysis. Bioinformatics analysis was performed to explore the potential role of the exosomal content on spermatogenesis. A total of 945 proteins were identified, 11 of which were closely related to spermatogenesis. A total of 2578 miRNAs were identified. Among them, 30 miRNAs demonstrated potential associations with male reproductive disorders, such as azoospermia, and spermatogenesis disorders. In particular, 11 out of these 30 miRNAs have been proven to be involved in spermatogenesis based on available evidence. This study provides a global view of the proteins and miRNAs from HTEC-Exos, suggesting that HTEC-Exos may function as potential effectors during the process of spermatogenesis.