Abstract
Sertoli cells play critical roles in regulating spermatogenesis and they can be reprogrammed to the cells of other lineages, highlighting that they have significant applications in reproductive and regenerative medicine. The fate determinations of Sertoli cells are regulated precisely by epigenetic factors. However, the expression, roles, and targets of microRNA (miRNA) in human Sertoli cells remain unknown. Here we have for the first time revealed that 174 miRNAs were distinctly expressed in human Sertoli cells between Sertoli-cell-only syndrome (SCOS) patients and obstructive azoospermia (OA) patients with normal spermatogenesis using miRNA microarrays and real time PCR, suggesting that these miRNAs may be associated with the pathogenesis of SCOS. MiR-133b is upregulated in Sertoli cells of SCOS patients compared to OA patients. Proliferation assays with miRNA mimics and inhibitors showed that miR-133b enhanced the proliferation of human Sertoli cells. Moreover, we demonstrated that GLI3 was a direct target of miR-133b and the expression of Cyclin B1 and Cyclin D1 was enhanced by miR-133b mimics but decreased by its inhibitors. Gene silencing of GLI3 using RNA inference stimulated the growth of human Sertoli cells. Collectively, miR-133b promoted the proliferation of human Sertoli cells by targeting GLI3. This study thus sheds novel insights into epigenetic regulation of human Sertoli cells and the etiology of azoospermia and offers new targets for treating male infertility.