Effect of miR-21-5p by targeting PDCD4 gene on proliferation and apoptosis of ovarian granulosa cells in rats with polycystic ovary syndrome and its molecular mechanism

Abstract

Objective To investigate the effect of miR-21-5p on proliferation and apoptosis of ovarian granulosa cells in rats with polycystic ovary syndrome (PCOS) and its molecular mechanism. Methods Rat PCOS model was established to collect ovarian granulosa cells. RT-qPCR was used to detect the expression of miR-21-5p and PDCD4 mRNA in ovarian granulosa cells of PCOS model rats and normal rats, Western blotting was used to detect the PDCD4 protein expression, and dual luciferase reporter gene assay was used to detect whether miR-21-5p was targeting PDCD4. NC-miRNA, miR-21-5p-mimics, NC-siRNA, PDCD4-siRNA, pcDNA, pcDNA-PDCD4 were transfected into PCOS rat ovarian granulosa cells, and cell proliferation and apoptosis were detected by MTT assay and flow cytometry. Results Compared with normal rats, the expression of miR-21-5p was significantly decreased (P<0.05) , and the expression of PDCD4 mRNA and protein was significantly increased (P<0.05) in ovarian granulosa cells of PCOS rats. Dual luciferase reporter gene assay confirmed that miR-21-5p targeted and negatively regulated the expression of PDCD4. Overexpression of miR-21-5p and inhibition of PDCD4 could promote the proliferation and inhibit apoptosis of ovarian granulosa cells in PCOS rats, while overexpression of PDCD4 reversed the effect of miR-21-5p overexpression on proliferation and apoptosis of ovarian granulosa cells in PCOS rats. Conclusions miR-21-5p inhibits apoptosis and promoted cell viability of ovarian granulosa cells in PCOS rats by targeting inhibition of PDCD4 expression. Key words: Polycystic ovary syndrome; Ovarian granular cells; miR-21-5p; PDCD4; Proliferation; Apoptosis