MiR-29c-5p regulates the function of buffalo granulosa cells to induce follicular atresia by targeting INHBA.

MicroRNAs (miRNAs) are involved in many physiological processes such as signal transduction, cell proliferation and apoptosis. Many studies have shown that miRNAs can regulate the process of follicular development. Our previous studies found that the expression of miR-29c-5p in buffalo atretic follicles was much higher than that in healthy follicles, suggesting that this miRNA may participate in the process of buffalo follicular atresia. In this study, we aim to explore to the role and molecular mechanisms of miR-29c-5p on the functions of buffalo granulosa cells (GCs). GCs cultured in vitro were transfected with miR-29c-5p mimics and its inhibitor, respectively, and it was found that the mimics significantly increased the apoptotic rate of GCs. They also inhibited the proliferation of GCs and the secretion of steroid hormones. The effect of the inhibitor was opposite to that of the mimics. MiR-29c-5p was subsequently shown to target the inhibin subunit beta A, (INHBA). Overexpression of INHBA could promote the production of activin A and inhibin A, and then reverse the effect of miR-29c-5p on buffalo GCs. In conclusion, these results suggest that miR-29c-5p promotes apoptosis and inhibits proliferation and steroidogenesis by targeting INHBA in buffalo GCs. This may ultimately promote atresia in buffalo follicles.