Research On The Relationship Among SRAGE And Ovarian Granulosa Cells Apoptosis And Oocyte Maturity In Women With PCOS

BackgroundPolycystic ovary syndrome(PCOS)is a most common endocrine disorder among reproductive-aged,affecting about 5%-15%women.The main characteristics of PCOS are ovulation disorders,hyperandrogenism and insulin resistance(IR).Granulosa cells and oocytesclosely related to each other by nutrient exchanges and transmissions of biological signals.The expression of related apoptotic factors precisely regulates follicular growth,development and maturation,which is the basis of periodic growth and regression of follicles.The abnormal apoptosis of granulosa cells is thought to be an important cause of abnormal follicular development in PCOS.Studies of the regulation of ovarian granulosa cell apoptosis lays a foundation for the exploration of oocytes development and some reproductive endocrine and metabolic diseases such PCOS.Advancd glycation end products(AGEs)is non-enzymatic combination of carbohydrates and proteins.The bind of AGEs with Receptor of Advanced Glycation Endproducts(RAGE)can induce apoptosis of many kinds of cells such as rat osteoblasts,mouse chondrocytes,fibroblasts,human adipose tissue stem cellsand lead to the development of a variety of human diseases,such as type 2 diabetes,cardiovascular diseases,aging,Chronic inflammatory reaction and neurodegenerative diseases.The expression of AGEs and RAGE were detected in ovarian granulosa cells of ovarian tissues,and studies has discoved that PCOS women showed a significantly higher expression of AGEs and RAGE in follicular fluid than that in normal women,thus suggesting that AGEs are associated with PCOS.Another finding showed that the restrain of AGEs-induced intracellular reactive oxygen may avoid the excess apoptosis of mouse granulosa cells.sRAGE is an endogenous subtype of RAGE,which can compete with RAGE for binding to ligands,thereby inhibiting multiple cell signaling passway induced by AGEs-RAGE axis way.Studies have shown that sRAGE can inhibit cardiomyocyte apoptosis induced by ischemia-reperfusion injury in myocardial infarction and improve cardiac contractility.sRAGE is thought to be closely related to female fecundity;The relationship between sRAGE and granulosa cell apoptosis or follicle development disorder need further exploration.ObjectiveTo explore relationships among sRAGE levels in FF,apoptosis of granulosa cells and maturation of oocytes in patients with PCOS.Materials and methodsClinical data of 61 patients who underwent their first intracytoplasmic sperm injection(ICSI)cycle were collected.Among them,The PCOS group included 30women with PCOS,and the diagnosis of PCOS according to the 2003 Rotterdam criteria.The control group included 31 non-PCOS patients.All the subjects in the two groups aged 25 to 35 and their Body Mass Index ranged from 18 to 25.The follicular fluid and granulosa cells were received on the day of oocyte retrieval.The concentration of sRAGE in follicular fluid was measured by enzyme-linked immunosorbent assay(ELISA).The apoptosis rate of ovarian granulosa cells was measured by flow cytometry.The expression of caspase-3 protein was detected by Western Blot,and the retrieved oocytes numbers and mature oocytes numbers were recorded.We compared the sRAGE concentration in FF,ovarian granulosa cell apoptosis,caspase-3 protein expression in the two groups.And the correlation between sRAGE levels in FF,ovarian granulosa cell apoptosis rate and MII oocytes rate in the PCOS group were explored.The study also detected factors affecting oocyte maturation in PCOS patients.Results1.Women in PCOS group showed a significant lower sRAGE levels and MII oocytes rate than women in the non-PCOS group(P<0.05).The apoptosis rate of granulosa cells and caspase-3 levels was significantly higher in PCOS group than non-PCOS group(P<0.05).2.In PCOS group,the sRAGE levels was negatively correlated with the apoptotic rate of granulosa cells(r=-0.687,P<0.05);The apoptosis rate of granulosa cells was negatively correlated with the MII oocytes rate(r=-0.665,P<0.05);sRAGE levels was positively correlated with the MII oocytes rate(r=0.579,P<0.05).3.The rate of MII oocytes in non-PCOS group was affected by TSH and apoptotic rate(R~2=0.637,F=24.590,P<0.05),and the MII oocytes rate was mainly affected by apoptotic rate(beta=-0.807,P<0.05)and also affected by TSH(beta=-0.255,P<0.05);In PCOS group MII oocytes rate was affected by sRAGE levels in FF and BMI(R~2=0.442,F=10.298,P<0.05).while,the MII oocytes rate was mainly affected by sRAGE in follicular fluid(beta=0.570,P<0.05)and also affected by BMI(beta=-0.313,P<0.05);ConclusionsAbnormal apoptosis of granulosa cells in PCOS patients affects its oocyte maturation,and sRAGE is closely related to the apoptosis of granulosa cells,which provides new ideas for the study of oocytes immaturation in PCOS women.