Sertoli cells-derived exosomal miR-30a-5p regulates ubiquitin E3 ligase Zeb2 to affect the spermatogonial stem cells proliferation and differentiation

The role of spermatogonial stem cells (SSCs) is crucial in spermatogenesis, and extracellular vesicles (EVs) have been the focus of research as an important intercellular communication mechanism. Various endogenous regulatory factors secreted by Sertoli cells (SCs) can affect the self-maintenance and regeneration of SSCs, but little is known about the roles of SCs-derived exosomal microRNAs (miRNAs) on SSCs. In this study, we aimed to explore the regulation of the SCs-derived exosomal miR-30a-5p on SSCs proliferation and differentiation. EVs from the SCs were detected by electron microscopy and nanoparticle tracking analysis (NTA). Subsequently, the SSCs were treated with the SCs-derived extracellular vesicles (SCs-EVs). CCK-8 assay and EdU staining was applied to detect the cell proliferation, and the results indicated that SCs-EVs promoted the SSCs proliferation. Western blot detection of the SSCs markers (Gfrα1, Plzf, Stra8, and C-kit) indicated that SCs-EVs promoted the SSCs differentiation. Additionally, we found that SCs-EVs secreted miR-30a-5p to show the promoting effects. Besides, we discovered that miR-30a-5p targeted zinc finger E-box binding homeobox 2 (Zeb2) to regulate the ubiquitination of fibroblast growth factor 9 (Fgf9) in SSCs. miR-30a-3p/Zeb2/Fgf9 promoted the SSCs proliferation and differentiation by activating the mitogen‑activated protein kinase (MAPK) signaling pathway. Taken together, our study showed that SCs-EVs can transport miR-30a-5p to SSCs and affect SSCs proliferation and differentiation by regulating the MAPK signaling pathway via Zeb2/Fgf9. This paper disclosed a novel molecular mechanism that regulates SSCs proliferation and differentiation, which could be valuable for the treatment of male infertility.