温和灸对动脉粥样硬化兔沉默信息调节因子1/核因子-κB信号通路的影响

Effect of mild moxibustion on SIRT1/NF-κB signaling in atherosclerotic rabbits

目的:观察温和灸对动脉粥样硬化(AS)家兔血脂水平、主动脉弓部组织病理形态结构、胸主动脉沉默信息调节因子1(SIRT1)/核因子-κB(NF-κB)信号通路的影响,探讨温和灸治疗AS的作用机制。方法:将家兔随机分为空白组12只、模型组11只、温和灸组11只、温和灸+阻断剂组(阻断剂组)12只。采用高脂饲料饲养8周结合免疫反应损伤制备AS家兔模型。温和灸组选取“膻中”“神阙”及双侧“内关”“血海”穴进行艾灸,每次30min,每周3次,连续4周。阻断剂组在施灸前30min腹腔注射SIRT1阻断剂EX527(5mg·kg^(-1)·d^(-1)),艾灸干预同温和灸组,每周3次,连续4周。采用酶法测定血清甘油三酯(TG)、总胆固醇(TC)含量,比色法测定血清低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)含量;苏丹Ⅳ染色法观察家兔主动脉弓部组织病理形态结构;Western blot和实时荧光定量-PCR法检测胸主动脉SIRT1、NF-κB蛋白和mRNA表达量。结果:与空白组比较,模型组家兔血清TG、TC、LDL-C含量显著升高(P<0.01),HDL-C含量显著降低(P<0.01),主动脉弓部组织结构界限不清,脂质浸润明显,胸主动脉SIRT1 mRNA表达量显著降低(P<0.01),NF-κB蛋白和mRNA表达量显著升高(P<0.05,P<0.01)。与模型组比较,温和灸组血清TG、TC、LDL-C含量降低(P<0.01,P<0.05),HDL-C含量升高(P<0.05),主动脉弓部组织结构较清晰,脂质浸润明显减轻,胸主动脉SIRT1蛋白和mRNA表达量升高(P<0.05,P<0.01),NF-κB蛋白和mRNA表达量显著降低(P<0.01);阻断剂组各项指标与模型组比较差异无统计学意义(P>0.05)。与温和灸组比较,阻断剂组血清TG、TC、LDL-C含量升高(P<0.01,P<0.05),HDL-C含量降低(P<0.05),胸主动脉SIRT1蛋白和mRNA表达量显著降低(P<0.01),NF-κB蛋白表达量显著升高(P<0.01)。结论:温和灸能改善血脂水平,减轻内皮损伤,促进内膜修复,其作用机制可能与调控SIRT1/NF-κB信号通路有关。

Objective To observe the effect of mild moxibustion on blood lipid,histopathological structure of the aortic arch,thoracic aortic silent information regulator 1(SIRT1)/nuclear factorκB(NF-κB)signaling pathway in atherosclerosis(AS)rabbits,so as to explore its underlying mechanisms in improving AS.Methods Sixty male rabbits were randomly divided into control group(n=12),model group(n=11),mild moxibustion group(n=11),mild moxibustion+blocker(blocker)group(n=12).The AS model was established by feeding the rabbits with high-fat forage for 8weeks,followed by immune response damage.Mild moxibustion was applied to“Danzhong”(CV17),“Shenque”(CV8)and“Neiguan”(PC6,bilateral)and“Xuehai”(SP10,bilateral)for 30min,once daily,3times a week for 4weeks.Rabbits of the blocker group received intraperitoneal injec-tion of EX527(a selective inhibitor of SIRT1,5mg·kg^(-1)·d^(-1))30min before moxibustion.Rabbits of the control and model groups were only grabbed and fixed without intervention.After the intervention,the contents of serum triglyceride(TG)and total cholesterol(TC)were determined by enzymatic method,and those of serum low-density lipoprotein cholesterol(LDL-C)and high-density lipoprotein cholesterol(HDL-C)were determined by colorimetric method.The SudanⅣstaining was employed to observe the histopathological structure of the aortic arch,and Western blot and fluorescence quantitative real time-PCR were used to detect the expressions of SIRT1and NF-κB proteins and mRNAs in the thoracic aorta,respectively.Results Compared with the control group,the contents of serum TG,TC and LDL-C and the expression levels of NF-κB protein and mRNA were significantly increased(P<0.01,P<0.05),whereas the content of HDL-C and the expression of SIRT1mRNA markedly decreased in the model group(P<0.01).After mild moxibustion,the contents of serum TG,TC,and LDL-C and the expression of NF-κB protein and mRNA were significantly down-regulated(P<0.01,P<0.05),while the content of HDL-C and the expression levels of SIRT1protein and mRNA significantly up-regulated in the mild moxibustion group(P<0.05,P<0.01).There were no significant differences between the blocker and model groups in all the indexes(P>0.05).Compared with the mild moxibustion group,the serum TG,TC,and LDL-C contents and NF-κB protein expression were significantly increased(P<0.01,P<0.05),and HDL-C content and the expression of SIRT1protein and mRNA significantly decreased(P<0.05,P<0.01)in the blocker group.SudanⅣstaining showed vague structure of the aortic arch with obvious lipid infiltration in the model group,which was relatively milder in the mild moxibustion.Conclusion Mild-moxibustion can reduce blood lipid levels and endothelial damage in atherosclerotic rabbits,which may be related to its function in regulating SIRT1/NF-κB signaling pathway.