The Mechanism Discussion Of MiR-509-3p Participating In The Pathogenesis Of Polycystic Ovary Syndrome By Targeting IFG2BP2

ObjectivePolycystic ovary syndrome(PCOS)is one of the most common endocrine diseases in gynecology,and its exact etiology is still unknown.In PCOS patients,follicular maturation disorders can lead to infertility,and ovarian granulosa cells are essential for follicular development.mircroRNAs(miRNAs)is a type of single-stranded non-coding RNA with a size of about 20 to 24 nucleotides,which can bind to the 3'UTR of a target gene and negatively regulate its expression.Studies have shown that miRNAs is involved in regulating the function of ovarian granulosa cells.In the previous study of our research group,the PCOS rat model was successfully established by combining letrozole with high-fat diet,and miRNAs were sequenced in the ovarian tissues of rats in the PCOS model group and the control group,it was found that the expression of miR-509-3p was significantly up-regulated in the ovarian tissues of PCOS model rats.The purpose of this study was to investigate the effect of miR-509-3p on granulosa cells function,and to reveal the role and possible mechanism of miR-509-3p in the pathogenesis of PCOS,so as to provide theoretical basis for the exploration of the pathogenesis and therapeutic targets of PCOS.Method(1)The TargetScan database was used to predict the target genes of miR-509-3p.(2)qRT-PCR and Western blot were used to detect the expression of miR-509-3p and target gene IGF2BP2 in ovarian tissues of PCOS model rats and normal control rats.KGN cells were transfected with miR-509-3p mimics and inhibitors,and qRT-PCR and Western blot were used to detect changes in the expression of IGF2BP2.The double luciferase reporter assay was used to confirm the binding of miR-509-3p to the 3'UTR of IGF2BP2.(3)KGN cells were transfected with miR-509-3p mimics,miR-509-3p inhibitors and the siRNA of IGF2BP2,and CCK8 was used to detect cell proliferation,and flow cytometry was used to detect apoptosis.(4)KGN cells were transfected with miR-509-3p mimics and inhibitors,and Dot blot was used to detect changes in the mRNA m~6A level in KGN cells.Results(1)TargetScan database predicted that IGF2BP2 was a target gene of miR-509-3p.(2)The results of qRT-PCR and Western blot showed that compared with the control group,the expression of miR-509-3p was up-regulated(P<0.01)and the expression of IGF2BP2 was down-regulated(P<0.05)in the ovarian tissues of PCOS rats;miR-509-3p could negatively regulate the expression of IGF2BP2 in KGN cells(P<0.01).Dual luciferase reporter assay confirmed that miR-509-3p can target the3'UTR of IGF2BP2(P<0.05).(3)CCK8 and flow cytometry results showed that miR-509-3p mimics inhibited KGN cell proliferation(P<0.05)and promoted apoptosis(P<0.01),while miR-509-3p inhibitors had the opposite effect(P<0.05)and IGF2BP2 siRNA inhibited KGN cell proliferation(P<0.01)and promoted apoptosis(P<0.01).(4)Dot blot results showed that miR-509-3p mimics down-regulated the m~6A level of mRNA in KGN cells(P<0.01),while miR-509-3p inhibitors up-regulated the m~6A level of mRNA in KGN cells(P<0.01).ConclusionThe expression of miR-509-3p was up-regulated in the ovary tissues of PCOS rats,and miR-509-3p may down-regulate the mRNA m~6A level of cells by targeting IGF2BP2,thereby inhibiting the proliferation of granulosa cells,promoting the apoptosis of granulosa cells,and participating in the occurrence and development of PCOS.