MicroRNA-141-3p targets DAPK1 and inhibits apoptosis in rat ovarian granulosa cells

The polycystic ovary syndrome (PCOS) is a complex and heterogeneous endocrine disorder. MicroRNAs negatively regulate the expression of target genes at posttranscriptional level by binding to the 3 untranslated region of target genes. Our previous study showed that miR-141-3p was dramatically decreased in the ovaries of rat PCOS models. In this study, we aimed to characterize the target of miR-141-3p in rat ovarian granulosa cells. 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay showed that cell viability was dramatically increased when miR-141-3p was overexpressed but was decreased when miR-141-3p was interfered. Flow cytometry showed that cell apoptotic rate was dramatically decreased when miR-141-3p was overexpressed but was increased when miR-141-3p was interfered. Bioinformatics analysis predicted that death-associated protein kinase 1 (DAPK1) might be the target gene of miR-141-3p because the 3 untranslated region of DAPK1 contains sequences complementary to microRNA-141-3p. Transfection with miR-141-3p mimics and inhibitor into granulosa cells showed that both DAPK1 mRNA and protein levels were negatively correlated with miR-141-3p level. Dual-luciferase reporter assay established that DAPK1 was the target of miR-141-3p. Taken together, our data indicate that miR-141-3p may inhibit ovarian granulosa cell apoptosis via targeting DAPK1 and is involved in the etiology of PCOS.