Study On The Mechanism Of FTO Regulating Granulosa Cell Function Of PCOS Patients

BackgroundPolycystic ovary syndrome(PCOS)is a complex metabolic disease of reproductive endocrine system that affects the fertility of women of childbearing age with a high degree of genetic heterogeneity.The global prevalence rate is 5%to 15%.Clinical manifestations include oligoovulation or anovulation,ovarian polycystic changes,hirsutism,acne,etc.,and may be accompanied by metabolic abnormalities such as obesity,insulin resistance,(IR),dyslipidemia and so on.It affects many systems of the body and the lifelong health of women.The occurrence of PCOS is related to the high level of LH and the stagnation of ovarian follicular growth,and the latter is closely related to the disorder of follicular microenvironment and abnormal function of ovarian granulosa cells.PCOS is considered to be a polygenic genetic disease,but the pathogenesis is not clear and needs to be further explored..FTO(Fatmassandobesity-associated),which was first discovered as a human obesity gene,controls food transformation and energy consumption,and is closely related to body mass index and human obesity.Its abnormal regulation will indirectly increase the risk of a variety of diseases.M6A is the most widely distributed RNA chemical modification in eukaryotes,which is widely distributed in various tissues of human body.FTO is the earliest discovered m6ARNA demethylase,which participates in gene post-transcriptional modification by regulating m6AmRNA demethylation.Many studies have confirmed that FTO can participate in the occurrence and development of many diseases through m6A demethylation.A genome-wide association analysis(GWAS)study based on Chinese Han women shows that FTO single nucleotide polymorphism is associated with PCOS.Although it has been proved to play a key role in many diseases,the specific mechanism of the effect of FTO on PCOS granulosa cells is limited.Previous studies in our group have also confirmed that the expression of FTO is up-regulated in patients with PCOS,but because there is no in-depth study on the mechanism,it is not clear how FTO regulates the function of granulosa cells in patients with PCOS and how to participate in the occurrence and development of PCOS.Previous literature reports have confirmed the correlation between FTO and PCOS.Previous studies of our group have confirmed that the expression of FTO in PCOS patients is up-regulated.However,due to the lack of in-depth mechanism research,it is still unclear how FTO participates in the occurrence and development of PCOS.How to affect the function of granular cells in PCOS patients.PurposeTo explore the mechanism of FTO regulating the function of ovarian granulosa cells of PCOS patients.Methods27 patients with PCOS and 31 patients with normal ovulation cycle were recruited and divided into normal body recombination and overweight according to BMI.The expression of FTOmRNA and protein in granulosa cells was detected by RT-qPCR and WesternBlotting.Lentivirus was used to down-regulate the expression of FTO in KGN cells to explore its effects on the expression of PCOS susceptibility genes AMHRII and LHCGR in granulosa cells,and on the other hand to explore its effects on granulosa cell cycle,proliferation and apoptosis.Results1.In normal weight and overweight groups:the expression of FTO in PCOS granulosa cells was significantly higher than that in normal ovulation group(normal weight:P<0.01,overweight:P<0.05);2.In normal weight and overweight groups:the expression of AMHRII and LHCGR in PCOS granulosa cells was significantly higher than that in normal ovulation group(normal weight AMHRII:p<0.01,normal weight LHCGR:p<0.01,overweight AMHRII:p<0.05,overweight LHCGR:p<0.05);3.Down-regulating the expression of FTO in KGN cells,the expression levels of AMHRII,LHCGR were significantly decreased(AMHRII(p<0.001),LHCGR(p<0.0001);4.Down-regulating the expression of FTO in KGN cells.The proportion of cells in the stage of DNA synthesis was significantly higher than that in the control group(p<0.001).The expression of apoptosis-related gene Bcl-2 was increased(p<0.05),and the expression of Bax was decreased(p<0.05).Conclusion1.FTO,AMHRII and LHCGR are highly expressed in granulosa cells from patients with PCOS;2.Down-regulation of FTO affects the expression of AMHRII and LHCGR in granulosa cells,but does not change the location of AMHRII and LHCGR protein in granulosa cells;3.Down-regulation of FTO can regulate the proliferation and apoptosis of granulosa cells by regulating the expression of apoptosis-related genes Bcl-2,Bax and cell cycle.