Irisin对多囊卵巢综合征大鼠卵巢胰岛素抵抗的影响

Effect of irisin on ovarian insulin resistance in rats with polycystic ovary syndrome

目的探讨鸢尾素(Irisin)对多囊卵巢综合征(PCOS)大鼠卵巢胰岛素抵抗的影响及其可能的作用机制。方法选择4周龄雌性SD大鼠45只,随机分为对照组、模型组、Irisin组,每组15只。模型组、Irisin组经颈背部皮下注射脱氢表雄酮0.06 mg/g+0.2 mL注射油剂,对照组每日颈背部皮下注射等体积油剂,连续20 d;第21天开始,Irisin组每日腹腔注射重组人Irisin 100 ng/g,对照组和模型组每日腹腔注射等量生理盐水,连续14 d。建模成功次日,取眼眶静脉血,离心留取血清,采用ELISA法检测血清胰岛素;末次腹腔注射后6 h处死,采集腹主动脉血,离心留取血清,采用ELISA法检测血清胰岛素。无菌条件下摘取双侧卵巢,取右侧卵巢组织,采用Western blotting法检测胰岛素受体底物2(IRS-2)、葡萄糖转运子4(Glut4)、磷脂酰肌醇3激酶(PI3K)p85α亚基蛋白表达;取左侧卵巢组织,采用RT-qPCR法检测IRS-2、Glut4、PI3K p85αmRNA表达。结果建模成功后,模型组、Irisin组血清胰岛素水平均高于对照组(P均<0.05);末次腹腔注射后,模型组血清胰岛素水平高于对照组(P<0.05),Irisin组血清胰岛素水平低于模型组(P<0.05),而Irisin组与对照组血清胰岛素水平比较差异无统计学意义(P>0.05)。与对照组比较,模型组与Irisin组卵巢组织IRS-2、Glut4、PI3K p85α蛋白和mRNA相对表达量均降低(P均<0.05);但Irisin组卵巢组织IRS-2、Glut4、PI3K p85α蛋白和mRNA相对表达量均高于模型组(P均<0.05)。结论Irisin能够改善PCOS大鼠卵巢胰岛素抵抗,其作用机制可能是通过增加卵巢胰岛素抵抗相关信号分子IRS-2、Glut4、PI3K p85α表达实现的。

Objective To explore the effect of irisin on ovarian insulin resistance in rats with polycystic ovary syndrome(PCOS)and its possible mechanism.Methods Female Sprague Dawley rats of 4 weeks old were randomly divided into the control group,model group,and irisin group,with 15 rats in each group.Rats in the model group and irisin group were injected subcutaneously with DHEA 0.06 mg/g+0.2 mL oil on the back of the neck,and the control group with equal volume of oil subcutaneously on the back of the neck every day,and the injection was continued for 20 days.Starting from day 21,the rats in the irisin group were intraperitoneally injected with recombinant human irisin 100 ng/g daily,and the control group and model group were intraperitoneally injected with the same amount of normal saline daily for 14 consecutive days.The next day after successful modeling,the orbital venous blood was collected,and was centrifuged to collect serum,and the serum insulin was detected by ELISA;at 6 h after the last intervention,blood was collected from abdominal aorta,and then was centrifuged to collect the serum.Serum insulin was detected by ELISA.We extracted both ovaries under aseptic conditions,took the right ovarian and used Western blotting to detect insulin receptor substrate 2(IRS-2),glucose transporter 4(Glut4),and phosphatidylinositol 3-kinase(PI3K)p85αsubunit protein expression;the left ovarian was taken,and the expression levels of IRS-2,Glut4,PI3K p85αmRNA were detected by RT-qPCR.Results After successful modeling,serum insulin levels in the model group and irisin group were significantly higher than that in the control group(all P<0.05);after the last intervention,the serum insulin level of the model group was higher than that of the control group(P<0.05),and the serum insulin level of the irisin group was lower than that of the model group(P<0.05);while there was no significant difference in serum insulin level between the irisin group and the control group(P>0.05).Compared with the control group,the relative expression levels of IRS-2,Glut4,PI3K p85αprotein and mRNA in the ovarian tissues of the model group and the irisin group decreased(all P<0.05);however,the relative expression levels of IRS-2,Glut4,PI3K p85αprotein and mRNA were higher than those of the model group(all P<0.05).Conclusion Irisin can improve ovarian insulin resistance in PCOS rats probably by increasing ovarian insulin resistance-related signals IRS-2,Glut4,and PI3K p85α.