葛根素通过AMPK/mTOR通路激活自噬治疗小鼠高脂血症

Puerarin activates autophagy through AMPK/mTOR pathway to treat hyperlipidemia in mice

本研究旨在探讨葛根素(Puerarin, PUE)对高脂血症(Hyperlipidemia, HLP)模型小鼠治疗效果的机制.实验选用C57BL/6J品种小鼠,随机分为空白组(Control)、模型组(Model)以及葛根素低、中、高剂量治疗组(PUE-L、PUE-M、PUE-H).成功构建高脂血症模型后,对小鼠进行了为期4周的葛根素干预治疗,并采用试剂盒检测了小鼠血脂谱的变化情况.此外,观察小鼠肝脏组织的病理变化,并通过Western blot方法对肝脏组织中的关键蛋白进行了检测,包括腺苷酸活化蛋白激酶(AMPK)与雷帕霉素哺乳动物靶蛋白(mTOR)信号通路相关蛋白、脂质代谢的关键调控蛋白固醇调节元件结合蛋白(SREBP)、以及自噬过程中的微管相关蛋白轻链3(LC3)和自噬底物(P62)的表达水平.进一步使用了定量聚合酶链反应(q-PCR)技术,来检测肝组织中乙酰辅酶A羧化酶(ACC)、脂肪酸合成酶(FAS)、固醇调节元件结合蛋白-1c(SREBP-1c)的mRNA转录水平,以及AMPK/mTOR信号通路相关的mRNA和炎症因子的mRNA的转录水平.相较于模型组,葛根素处理组小鼠血清中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)的水平明显下降,而高密度脂蛋白胆固醇(HDL-C)的水平则显著上升.肝脏组织中,细胞空泡样变化及脂滴积聚在葛根素干预后明显减少.在给药后,肝组织中的ACC、FAS、SREBP-1c mRNA的相对表达量有所降低,脂多糖(Lipopolysaccharides, LPS)和促炎因子肿瘤坏死因子-α(Tumor Necrosis Factor-α,TNF-α)、白细胞介素-8(Interleukin-8,IL-8)的表达下降,而抗炎因子白细胞介素-4(Interleukin-4,IL-4)和白细胞介素-10(Interleukin-10,IL-10)的表达水平则有所上升.此外,小鼠肝脏组织中的mTOR、SREBP、P62蛋白水平降低,而AMPK、p-AMPK、LC3蛋白的表达水平则增加.综上所述,实验结果表明,葛根素能够有效改善高脂血症模型小鼠的血脂谱,并降低炎症反应.其作用机制可能与葛根素调节AMPK/mTOR信号通路,促进自噬过程的激活有关.这些发现为高脂血症的治疗提供了新的视角,特别是在利用植物药物治疗的方面.

The aim of this study was to investigate the mechanism of therapeutic effect of puerarin on Hyperlipidemia(HLP)model mice.C57BL/6J mice were randomly divided into blank Control group(Control),disease Model group(Model)and puerarin low-dose,medium-dose and high-dose groups(PUE-L,PUE-M,PUE-H).After the successful construction of the hyperlipidemia model,the mice were treated with puerarin for 4 weeks,and the changes of the lipid profile of the mice were detected by the kit.In addition,pathological changes of mouse liver tissues were observed,and key proteins in liver tissues were detected by Western blot.They included the expression levels of adenylate activated protein kinase(AMPK)and rapamycin mammalian target protein(mTOR)signaling pathway,sterol regulatory element binding protein(SREBP),a key regulatory protein of lipid metabolism,and microtubule-associated protein light chain 3(LC3)and autophagy substrate(P62)during autophagy.Further,we used quantitative polymerase chain reaction(q-PCR)to detect the mRNA expression of acetyl-CoA carboxylase(ACC),fatty acid synthetase(FAS),sterol regulatory element-binding protein-1c(SREGBP-1C)in liver tissue.And the expression levels of mRNA and inflammatory factors related to AMPK/mTOR signaling pathway.Compared with the model group,the levels of total cholesterol(TC),triglyceride(TG)and low density lipoprotein cholesterol(LDL-C)in the serum of puerarin treated group were significantly decreased,while the levels of high density lipoprotein cholesterol(HDL-C)were significantly increased.In liver tissue,the vacuole-like changes and lipid droplet accumulation were significantly reduced after puerarin intervention.After administration,the relative expression levels of ACC,FAS and SREBP-1c mRNA in liver tissue decreased,the expression levels of LPS and pro-inflammatory factors TNF-αand IL-8 decreased,while the expression levels of anti-inflammatory factors IL-4 and IL-10 increased.In addition,the protein levels of mTOR,SREBP and P62 were decreased,while the expression levels of AMPK,p-AMPK and LC3 were increased.In summary,the experimental results show that puerarin can effectively improve the blood lipid profile of hyperlipidemia model mice and reduce the inflammatory response.The mechanism of action may be related to the regulation of AMPK/mTOR signaling pathway by puerarin,which promotes the activation of autophagy.These findings provide a new perspective on the treatment of hyperlipidemia,especially in the use of plant medicine.