电针对胰岛素抵抗大鼠下丘脑自噬活性的影响

Effect of electroacupuncture on autophagy activity in the hypothalamus of insulin resistant rats

目的观察电针对胰岛素抵抗(insulin resistance,IR)大鼠下丘脑自噬调控基因Atg1、Atg13和Beclin-1表达及糖原合成酶激酶-3β(glycogen synthase kinase-3β,GSK3β)表达的影响,探究针刺治疗IR的潜在机制。方法将45只清洁级Wistar大鼠随机分为正常组(15只)和模型制备组(30只)。正常组予常规饲养,模型制备组予高脂饲料和10%的果糖水饲养8周,制备IR模型。造模成功后,将模型制备组30只大鼠随机分为模型组(15只)和电针组(15只)。电针组大鼠行电针干预。分别于造模成功后及干预后,采用微量血糖仪和酶联免疫吸附法测定大鼠空腹血糖(fasting blood glucose,FBG)及空腹胰岛素(fasting insulin,FINS),计算胰岛素抵抗指数(insulin resistance index,IRI),评定大鼠IR程度。用Western blot和real-time PCR法检测下丘脑组织Atg1、Atg13、Beclin-1、GSK3βmRNA和蛋白表达,评价电针对胰岛素抵抗大鼠下丘脑自噬活性的影响。结果造模后,与正常组比较,模型制备组大鼠IRI均明显升高(P<0.05)。干预后,与正常组比较,模型组大鼠Atg1、Atg13、Beclin-1、GSK3βmRNA和蛋白表达升高(P<0.05);与模型组比较,电针组Atg1、Atg13、Beclin-1、GSK3βmRNA和蛋白表达均降低(P<0.05),IRI降低(P<0.05)。结论电针可明显改善高脂高糖诱导的IR,其机制可能与下调自噬相关因子Atg1、Atg13、Beclin-1表达从而抑制下丘脑细胞过度自噬以及降低GSK3β的表达有关。

Objective To observe the effects of electroacupuncture on the expression of autophagy regulatory genes Atg1,Atg13,Beclin 1,and glycogen syn-thase kinase-3(GSK3β)protein in the hypothalamus of insulin resistant rats and explore the potential mechanism of acupuncture in treating insulin resistance.Method Forty-five clean Wistar rats were randomly divided into a normal group(15 rats)and a modeling group(30 rats).The normal group was fed conventionally,and the modeling group was fed a high-fat diet with 10% fructose water for 8 weeks to prepare the insulin resistant rat model.After successful modeling,30 rats in the modeling group were further randomized into a model group(15 rats)and an electroacupuncture group(15 rats).Rats in the electroacupuncture group received electroacupuncture intervention.The fasting blood glucose(FBG)and fasting insulin(FINS)were detected using a micro-glucometer and enzyme-linked immunosorbent assay(ELISA),and the insulin resistance index(IRI)was calculated to evaluate the degree of insulin resistance.The mRNA and protein expression levels of Atg1,Atg13,Beclin-1,and GSK3β in the hypothalamus tissues were examined using Western blot and real-time polymerase chain reaction(PCR)to assess the effect of electroacupuncture on autophagy activity in the hypothalamus of insulin resistant rats.Result After modeling,the IRI increased markedly in the modeling group compared with the normal group(P<0.05).After the intervention,the mRNA and protein expression levels of Atg1,Atg13,Beclin-1,and GSK3β increased in the model group compared with the normal group(P<0.05);compared with the model group,the mRNA and protein expression levels of Atg1,Atg13,Beclin-1,and GSK3β dropped in the electroacupuncture group(P<0.05),as well as the IRI(P<0.05).Conclusion Electroacupuncture can significantly improve insulin resistance induced by high fat and high sugar.The mechanism may be related to inhibiting the excessive autophagy of hypothalamic cells by down-regulating the expression of autophagy-related factors Atg1,Atg13,and Beclin-1 and reducing the expression of GSK3β.