MiR-103a-3p Regulates Granular Cell Proliferation And Apoptosis By Targeting PTEN

Background: Granulosa cells are one of the functional cells of follicles and play an important role in follicular development,maturation,ovulation and atresia.Granulosa cell dysfunction will cause abnormal follicular development,follicular atresia,and thus lead to abnormal ovulation.Polycystic ovary syndrome(PCOS)is a common reproductive endocrine disease in women of childbearing age,and ovulation disorder is one of its main clinical features.,so the granular cell function abnormalities are closely associated with the occurrence/development of PCOS.Micrornas(miRNAs)are endogenous non-coding small RNAs that play an endogenous regulatory role through targeted mRNAs and play an important role in cell growth,metabolism,apoptosis and other aspects,and thus participate in the occurrence and development of a variety of diseases.Studies have found that a variety of miRNAs play an important regulatory role in granulosa cell function and therefore affect follicular development.The abnormal high expression of miR-103a-3p in serum and granulosa cells of PCOS patients may be related to theregulation of granulosa cell function,but its molecular mechanism and effect on PCOS are still unclear.Therefore,this paper intends to take granulosa cell lines as the research object,observe that the effect of overexpression of miR-103a-3p on the proliferation and apoptosis of granulosa cells,analyze and discuss its possible mechanism,and provide new experimental basis for elucidate the molecular mechanism of abnormal follicular development and the etiology and pathogenesis of PCOS.Methods: KGN cell lines were cultured in vitro,and quantitative real-time PCR(qRT-PCR)was used to detect the expression of miR-103a-3p in KGN cells;Transiently transfect miR-103a-3p mimics and corresponding miR-control to KGN cells,and detect the transfection efficiency of miR-103a-3p by fluorescence microscopy and qRT-PCR;flow cytometry,EdU staining and Hoechst staining were used to detect the proliferation and apoptosis of granulosa cells;Bioinformatics and dual luciferase reporter genes were used to identify the interaction between miR-103a-3p and the target gene PTEN;Using cellular immunofluorescence technology,Western blotting immunoblotting technology and qRT-PCR to detect the effect of miR-103a-3p on PTEN expression in granular cells;After overexpression of PTEN,flow cytometry and MTT were used to observe the effects of miR-103a-3p on the proliferation and apoptosis of KGN cells.Results: 1)qRT-PCR detected that there was miR-103a-3p expression in KGN cells,miR-103a-3p mimics could be transfected into KGN cells,so that the expression of miR-103a-3p in cells was significantly higher than that of the control group(P<0.05).2)Compared with miR-control,overexpression of miR-103a-3p significantly inhibited the activity of granulosa cells and blocked cells in the G0 / G1 phase,and the apoptosis rate was significantly increased(P<0.05).3)miR-103a-3p can specifically bind to the PTEN 3' non-coding region(3'-UTR),and after transfection with miR-103a-3p mimics into KGN cells,the mRNA and protein levels of PTEN are significantly lower than control group(P<0.05).4)Compared with the miR-103a-3p overexpression group,the miR-103a-3p overexpression and PTEN overexpression co-treatment groups had significantly promoted the capacity of cell proliferation,while reducing the apoptosis rate(P<0.05).Conclusion: miR-103a-3p can inhibit the proliferation and promote the apoptosis of granulosa cells.The mechanism may be related to the targeted regulation of PTEN expression in granulosa cells.