电针对高脂饮食诱导的肥胖大鼠下丘脑沉默信息调节因子1、叉头状转录因子O1及阿黑皮素原的影响

Effect of electroacupuncture on silent information regulator 1,fork head transcription factor O1 and proopiomelanocortin in the hypothalamus of rats with obesity induced by high-fat diet

目的:观察电针对高脂饮食诱导的肥胖(DIO)大鼠下丘脑沉默信息调节因子1(SIRT1)、叉头状转录因子O1(FoxO1)及阿黑皮素原(POMC)的影响,探讨电针调节中枢食欲肽减肥的作用机制。方法:雄性Wistar大鼠随机分为正常组、模型组、电针组、电针+抑制剂组(针+抑组)、抑制剂组、假手术组,每组10只。采用高脂饮食喂养诱导DIO大鼠模型。电针组和针+抑组电针"丰隆""中脘""关元""足三里"穴,10min/次;针+抑组和抑制剂组予以第三脑室置管并注射SIRT1特异性拮抗剂EX-527;假手术组予以第三脑室内置管,并注射人工脑脊液;均每周治疗3次,共治疗8周。观察各组大鼠治疗前后体质量、进食量、Lee’s指数,全自动生化分析仪检测大鼠血清胆固醇(TC)、甘油三酯(TG)、游离脂肪酸(FFA)含量,Western blot法检测大鼠下丘脑组织SIRT1、FoxO1、乙酰化FoxO1(AC-FoxO1)、POMC蛋白的表达水平。结果:治疗前,与正常组比较,模型组、电针组、针+抑组、抑制剂组、假手术组的体质量、进食量均明显升高(P<0.01),模型组和假手术组Lee’s指数增高(P<0.05)。治疗后,与模型组比较,电针组、针+抑组大鼠体质量、进食量、TC含量、AC-FoxO1表达量均显著降低(P<0.01,P<0.05),SIRT1、FoxO1和POMC表达量均明显升高(P<0.01,P<0.05);电针组Lee’s指数及血清TG、FFA含量显著降低(P<0.05,P<0.01);抑制剂组进食量,血清TC、TG、FFA含量显著升高(P<0.01),SIRT1、FoxO1、POMC表达量显著降低(P<0.01,P<0.05)。与电针组比较,针+抑组与抑制剂组的体质量、进食量、Lee’s指数及TG、FFA含量,AC-FoxO1表达量均明显升高(P<0.01,P<0.05),SIRT1、FoxO1和POMC表达量均显著降低(P<0.01);抑制剂组血清TC含量显著升高(P<0.01)。与针+抑组比较,抑制剂组体质量、进食量及TC、TG、FFA含量,AC-FoxO1表达量显著增高(P<0.01),SIRT1、FoxO1和POMC表达量明显降低(P<0.01)。结论:电针能有效上调DIO大鼠下丘脑中SIRT1的表达,从而去乙酰化作用于FoxO1,并促进下游抑食欲肽POMC的表达,可能是电针减肥的效应机制之一。

Objective To investigate the effect of electroacupuncture(EA)on silent information regulator 1(SIRT1),forkhead transcription factor O1(FoxO1),and proopiomelanocortin(POMC)in the hypothalamus of rats with high-fat diet-induced obesity(DIO),as well as the mechanism of EA in regulating central appetite peptides to help lose weight.Methods Male Wistar rats were randomly divided into normal group,model group,EA group,EA+inhibitor group,inhibitor group,and shamoperation group,with 10 rats in each group.High-fat diet was used to establish a rat model of DIO.The rats in the EA group and EA+inhibitor group were given EA at"Fenglong"(ST40),"Zhongwan"(CV12),"Guanyuan"(CV4),and"Zusanli"(ST36)with continuous wave at a frequency of 2 Hz and an intensity of 1 mA,for 10 minutes each time.The rats in the EA+inhibitor group and inhibitor group were given tube placement in the third ventricle and injection of the specific SIRT1 antagonist EX-527.The rats in the sham-operation group were given tube placement in the third ventricle and injection of artificial cerebrospinal fluid.The above treatment was given 3 times a week for 8 weeks in total.Body weight,food intake,and Lee’s index were observed before and after treatment.An automatic biochemical analyzer was used to measure the serum levels of total cholesterol(TC),triglyceride(TG),and free fatty acid(FFA),and Western blot was used to measure the protein expression of SIRT1,FoxO1,acetylated FoxO1(AC-FoxO1),and POMC in the hypothalamus.Results Before treatment,the model group,the EA group,the EA+inhibitor group,the inhibitor group,and the sham-operation group had significantly higher body weight and food intake than the normal group(P<0.01),and the model group and the sham-operation group had a significantly higher Lee’s index than the normal group(P<0.05).Compared with the model group after treatment,the EA group and the EA+inhibitor group had significant reductions in body weight,food intake,TC,and the protein expression of AC-FoxO1(P<0.01,P<0.05)and significant increases in the protein expression of SIRT1,FoxO1 and POMC(P<0.01,P<0.05);the EA group had significant reductions in Lee’s index and the levels of TG,FFA(P<0.05,P<0.01);the inhibitor group had significant increases in food intake,the serum levels of TC,TG,FFA(P<0.01)and significant reductions in the protein expression of SIRT1,FoxO1 and POMC(P<0.01,P<0.05).Compared with the EA group,the EA+inhibitor group and the inhibitor group had significant increases in body weight,food intake,Lee’s index,the levels of TG,FFA and the protein expression of AC-FoxO1(P<0.01,P<0.05)and significant reductions in the protein expression of SIRT1,FoxO1 and POMC(P<0.01);the inhibitor group had significant increases in the serum levels of TC(P<0.01).Compared with the EA+inhibitor group,the inhibitor group had significant increases in body weight,food intake,the serum levels of TC,TG,FFA,and the protein expression of AC-FoxO1(P<0.01),as well as significant reductions in the protein expression of SIRT1,FoxO1 and POMC(P<0.01).Conclusion In rats with DIO,EA can effectively upregulate the expression of SIRT1 in the hypothalamus,exert a deacetylation effect on FoxO1,and promote the expression of the downstream appetite-inhibiting peptide POMC,which may be one of the mechanisms of EA to help lose weight by regulating central appetite peptides in the obesity model.