| Objective: Women of childbearing age have a high prevalence of Polycystic ovary syndrome(PCOS).A number of studies have suggested that IR works importantly on the pathogenesis of PCOS,which is connected with metabolic syndrome.The renin-angiotensin system(RAS)plays a protective role in IR.It is composed of the axis of ACE2/Ang1-7/Mas ang ACE/AngⅡ /AT1 R,which keep balance.Ang1-7 has been proved in cardiovascular system,liver and skeletal muscle cells,improving IR.Therefore,It is necessary to study the relationship between abnormal RAS and the local IR in the ovary in PCOS.In this experiment,we use ovary cells from rats to simulate the local IR of the ovary of human.With the interventions of AngⅡ,Ang1-7 and A779(Mas receptor inhibitor),we were supposed to observe the effects in glucose metabolism and the nsulin signal pathway.Explore whether Ang1-7 /Mas axis may improve the local IR in the ovary,which is expected to provide a new perspective for the treatment of PCOS.Methods:1 Induce insulin resistance model(IR model)Culture the rat ovarian granulosa cells with adding dexamethasone and insulin.We determined and calculated the glucose consumption of the cells to ensure the success of IR model.2 Test glucose consumption of the cells under differernt drugsIR model cells were divided into five groups: Ang1-7,AngⅡ,A779,Ang1-7+AngⅡ,Ang1-7+A779 group.We tested glucose consumption of the cells and calculated the glucose consumption.3 Western blot was used to detect the expression of Mas receptor proteinand key proteins of insulin signaling pathway : Akt,P-Akt,GSK-3β,P-GSK-3β,AS160,P-AS160 in each group.Results:1.Compared with the blank control group,we find the glucose consumption of the ovarian granulosa cells in the IR group decreased significantly,indicating the abnormal glucose metabolism in the IR group.That means the IR model was satisfactory.2.After adding Ang1-7,the glucose consumption of rat ovarian granulosa cell increases significantly,compared with the blank model(IR)group(P<0.05).By contrast,the glucose consumption decreased with AngⅡ.The glucose consumption of Ang1-7+AngⅡ group had no difference compared with the blank model group.3.Cells in Ang1-7+A779 group show glucose consumption increased(P<0.05).However,A779 group had no significant difference with blank model group in glucose consumption.4.Western Blot4.1 The expression of p-AKT/AKT,p-GSK-3β/GSK-3β and p-AS160/AS160 in each groupThere is no significant difference in the expression of AKT,GSK-3β and AS160 protein in each group,compared with the blank model group.In Ang1-7 group,p-AKT(P<0.05),p-GSK-3β(P<0.05),p-AS160(P<0.05)expression increases significantly.Similarly in AngⅡ group,p-AKT,p-GSK-3β,p-AS160 expression decreased(P<0.05).In Ang1-7+AngⅡgroup,p-AKT,p-GSK-3β,p-AS160 expression are significantly lower than cells from Ang1-7 group(P<0.05).After the co-work of Ang1-7+A779,the expression of p-AKT,p-GSK-3β and p-AS160 is also lower than cells in Ang1-7 group(P<0.05).However,the above changes are not observed in A779 group.4.2 Mas expressionCompared with the blank model group,the expression of Mas in Ang1-7group increases(P<0.05),while the expression of Mas in group A779 andAng1-7+A779 group decreases(P<0.05).Compared with the Ang1-7+A779 group,the expression of Mas in group A779 reduces(P<0.05).Conclusions:1.Dexamethasone and insulin can build the IR model.The phosphorylation level of AKT,GSK-3β,AS160 protein decreases in the model group.2.The effect of Ang1-7 on improving the glucose metabolism of rat ovarian granulosa cells in IR model is opposite to AngⅡ,which is worked by improving the expression of the phosphorylation level of AKT,GSK-3β,AS160 protein in insulin signaling pathway.3.The act of Ang1-7 on improvement of Mas,the glucose metabolism and insulin signal pathway is inhibited by adding A779,which means in the role of Ang1-7 on improvement of the glucose metabolism,its downstream Mas receptor is involved in the process. |
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