摘要
目的:探讨电针激活沉默信息调节因子1(SIRT1)/自噬相关蛋白7(ATG7)通路调控肝脏脂肪代谢改善胰岛素抵抗(IR)的机制。方法:50只Wistar雄性大鼠,随机挑选8只喂养标准饲料,为空白对照组;其余大鼠喂养高脂饲料8周,构建胰岛素抵抗大鼠模型。从造模成功的大鼠中挑选32只随机分为模型组、电针组、激动剂组和电针联合抑制剂组,每组8只。电针组给予“关元”“中脘”“足三里”“丰隆”电针干预,留针10 min;电针联合抑制剂组腹腔注射EX-527溶液,同步电针干预;激活剂组白藜芦醇溶液灌胃;均1次/2 d,3次/周,连续8周。记录各组大鼠干预前后体质量,全身胰岛素敏感性(GIR)。干预后,检测血清胰岛素(INS)、腹腔胰岛素耐量(IPITT)、血清高密度脂蛋白(HDL)、极低密度脂蛋白(VLDL)、肝脏总胆固醇(TC)和甘油三酯(TG)含量;采用Western blot法,检测并观察肝脏组织中固醇调节元件结合蛋白1c(SREBP-1c)、磷酸化糖原合成酶激酶3β(p-GSK3β)蛋白表达,RT-PCR及免疫荧光法检测SIRT1、ATG7基因及荧光表达。结果:与空白对照组比较,模型组大鼠GIR降低,差异具有统计学意义(P<0.01),血清INS含量、90 min与120 min IPITT、VLDL、肝脏TC及TG升高,差异具有统计学意义(P<0.01),血清HDL降低,差异具有统计学意义(P<0.01),SREBP、p-GSK3β蛋白表达增多,差异具有统计学意义(P<0.01),SIRT1、ATG7 mRNA、荧光密度降低,差异具有统计学意义(P<0.01)。与模型组比较,电针组大鼠GIR升高,差异具有统计学意义(P<0.01),血清INS含量、90 min IPITT降低,差异具有统计学意义(P<0.01),120 min IPITT,VLDL降低,差异具有统计学意义(P<0.05),HDL升高,差异具有统计学意义(P<0.05),肝脏TC、TG降低,差异具有统计学意义(P<0.01),SREBP蛋白表达减少,差异具有统计学意义(P<0.01),p-GSK3β蛋白表达减少,差异具有统计学意义(P<0.05),SIRT1mRNA表达增多,差异具有统计学意义,SIRT1荧光密度升高,差异具有统计学意义(P<0.05),ATG7 mRNA表达增多,差异具有统计学意义(P<0.05),ATG7荧光密度升高,差异具有统计学意义(P<0.01);激动剂组大鼠GIR升高,血清INS含量、90 min与120 min IPITT降低,差异具有统计学意义(P<0.01),HDL升高,差异具有统计学意义(P<0.05),VLDL降低,肝脏TC、TG降低,差异具有统计学意义(P<0.01),SREBP、p-GSK3β蛋白表达减少,差异具有统计学意义(P<0.05),SIRT1 mRNA、荧光密度升高,差异具有统计学意义(P<0.01),ATG7 mRNA、荧光密度升高,差异具有统计学意义(P<0.05)。与电针组比较,电针联合抑制剂组大鼠GIR降低,差异具有统计学意义(P<0.05),血清INS含量升高,差异具有统计学意义(P<0.05),90 min与120 min IPITT、VLDL升高,HDL降低,肝脏TC、TG升高,差异具有统计学意义(P<0.01),SREBP蛋白表达增多,差异具有统计学意义(P<0.05),p-GSK3β蛋白表达增多,SIRT1、ATG7 mRNA表达减少,SIRT1与ATG7荧光密度降低,差异具有统计学意义(P<0.05,P<0.01)。结论:电针提高大鼠胰岛素敏感性、改善胰岛素抵抗的作用,与上调肝脏SIRT1和ATG7水平、抑制成脂基因SREBP表达及改善脂肪代谢有关。
Objective:To explore the mechanism of electro-acupuncture(EA)in regulating liver lipid metabolism and improving insulin resistance(IR)by activating SIRT1/ATG7 pathway.Methods:8 rats were randomly selected from 50 Wistar male rats and were assigned into the blank control group.These 8 rats were given standard feed.The rest of the rats were fed with high-fat diet to build the IR model.From the successfully modeled rats,select 32 and randomly divided them into the model group and the EA group,the agonist group and the EA combined with inhibitor group,with 8 rats in each group.The EA group was intervened with electro-needling Guanyuan(RN4),Zhongwan(RN12),Zusanli(ST3)and Fenglong(ST40)for 10 minutes.The EA combined with inhibitor group was intraperioneally injected with EX-527 solution,simultaneously was given EA intervention.The agonist group was given resveratrol via gavage.All the interventions were once every other day,three times a week for 8 weeks.Body mass and glucose infusion rate(GIR)were recorded before and after the interventions in the groups.Serum contents of insulin(INS),intraperioneal insulin tolerance test(IPITT),high-dentsity Lipoprotein(HDL),very low-density lipoprotein(VLDL),liver total cholesterol(TC)and triglycerin(TG)were detected after the interventions in the groups.Western Blot method was used to detect the protein expressions of sterol regulatory element-binding protein 1c(SREBP-1c)and phosphorylated glycogen synthase kinase 3β(p-GSK3β)in liver tissues.RT-PCR and immunofluorescence were explored to detect the gene expressions and fluorescence expressions of SIRT1 and ATG7.Results:Compared with those in the blank control group,GIR was decreased(P<0.01),serum levels of INS,90 min and 120 min IPITT,VLDL,TC and TG were increased(P<0.01),serum level of HDL was decreased(P<0.01),protein expressions of SREBP and p-GSK3βwere increased(P<0.01),SIRT1 mRNA,ATG7 mRNA,and their fluorescence density were decreased in the model group(P<0.01).Compared with those in the model group,GIR was increased(P<0.01),serum levels of INS,90 min and 120 min IPITT and VLDL were decreased(P<0.01),serum level of HDL was increased(P<0.05),TC and TG were decreased(P<0.01),protein expressions of SREBP and p-GSK3βwere decreased(P<0.01,P<0.05),SIRT1 mRNA,ATG7 mRNA,and their fluorescence density were increased in the EA group(P<0.05,P<0.01).Compared with those in the model group,GIR was increased(P<0.01),serum levels of INS,90 min IPITT and 120 min IPITT were decreased(P<0.01),serum level of HDL was increased(P<0.05),VLDL,TC and TG were decreased(P<0.01),protein expressions of SREBP and p-GSK3βwere decreased(P<0.05),SIRT1 mRNA,ATG7 mRNA,and their fluorescence density were increased in the agonist group(P<0.05,P<0.01).Compared with those in the EA group,GIR was decreased(P<0.05),serum level of INS was increased(P<0.01),90 min IPITT,120 min IPITT and VLDL were increased(P<0.01),HDL was decreased(P<0.01),TC and TG were increased(P<0.01),protein expressions of SREBP and SIRT1 were increased(P<0.05,P<0.01),SIRT1 mRNA,ATG7 mRNA,and their fluorescence density were decreased in the EA combined with inhibitor group(P<0.05,P<0.01).Conclusion:EA can improve insulin sensitivity and improve insulin resistance in rats,which are related to up-regulating liver SIRT1 and ATG7 levels,inhibiting expression of lipid gene SREBP,and improving lipid metabolism.
作者
李鑫悦
陈丽
王静芝
汪梓铭
罗亲俊
LI Xinyue;CHEN Li;WANG Jingzhi;WANG Ziming;LUO Qinjun(Hubei University of Chinese Medicine,Wuhan 430065,China)
出处
《针灸临床杂志》
2024年第10期62-70,共9页
Journal of Clinical Acupuncture and Moxibustion
基金
国家自然科学基金,编号:81804170、81904276。
