Study On The Expression And Molecular Mechanism Of Apelin In Patients With Polycystic Ovary Syndrome

Part I Characteristics of serum Apelin levels in patients with polycystic ovary syndromeObjective:To investigate the expression of serum Apelin in patients with polycystic ovary syndrome(PCOS),and its correlations with sex hormones and metabolism.Methods:A total of 60 infertile patients,who visited the Reproductive Medicine Center of Zhongshan Boai Hospital from September 2015 to September 2017,were divided into PCOS group(30 cases)and non-PCOS infertile women(30 cases)as control group.ELISA was used to detect the levels of serum Apelin.The levels of fasting plasma glucose,insulin,and sex hormones were detected,too.Body mass index(BMI)and HOMA-IR were calculated,and the correlation of serum Apelin level with sex hormones and metabolic indexes was analyzed.Results:The level of serum Apelin in PCOS group was significantly higher than that in control group[(3.35±1.22)vs.(1.95±0.83)μg/L](P<0.05).HOMA-IR in PCOS group was also significantly higher than that in control group[(3.87±1.41)vs.(2.12±0.91)μg/L](P<0.05).Pearson correlation analysis showed that serum Apelin level was positive correlated with BMI and HOMA-IR(P<0.01).Conclusion:The levels of serum Apelin in PCOS patients increased,which were closely related to BMI and HOMA-IR.Part Ⅱ miR-424 suppresses the proliferation and promotes the apoptosis of KGN cells by targeting Apelin and APJ expressionObjective:This study aimed to investigate the roles of miR-424 in modulating Apelin expression and KGN functions.Methods:Sixty-nine infertile patients,who visited the Reproductive Medicine Center of Zhongshan Boai Hospital and underwent IVF-ET from October 2017 to December 2018,were divided into PCOS group(32 cases),non-PCOS infertile patients as control group(37 cases).Serum samples,follicular fluids and granulosa cells were collected and analyzed.Ovarian granulosa cell tumor KGN was obtained from Ricken Biological Source Center(Ricken,Japan),and the expressions of miRNAs in KGN were changed by transfection of specific mimics and inhibitors.Apelin level was deter分钟 ed by ELISA,gene and miR-424 expression were analyzed by quantitative RT-PCR method.Protein abundances were measured by Western blot.Association of miR-424 with genomic sequences were validated by dual-luciferase reporter assay.Apelin gene expression was overexpressed by LV-003 plasmid-mediated cell transfection.KGN cell proliferation was analyzed by MTS method,and its cell cycle progression and apoptosis were measured by flow cytometry.Results:1.Apelin concentration was significantly increased in serum and follicular fluid from PCOS patients(P<0.05),accompanied with accelerated APJ(Apelin receptor)expression and suppressed miR-424 expression in GCs.2.Apelin and APJ expression in KGN cells were suppressed by miR-424 mimics,by targeting Apelin and APJ 3’-UTR regions,which were recovered by miR-424 inhibitors.3.miR-424 inhibited KGN cell proliferation and cell cycle progression by down-regulating Cyclin-D/E expression.4.miR-424 promoted KGN cell apoptosis by increasing truncated Caspase-3 level.The regulation of KGN cell proliferation and apoptosis by miR-424 was mediated by directly suppressing apelin gene expression,but not the inhibition of Apelin peptide activity.Conclusion:The expression of Apelin and APJ was targeted and regulated by miR-424,and Apelin can inhibit the proliferation of KGN cells and promote their apoptosis.