电针对快速衰老小鼠肝脏自噬及脂质代谢的影响

目的: 研究电针对快衰老小鼠(SAMP8)肝脏中自噬相关因子LC3-Ⅱ、Beclin1、Atg7、P62表达的影响,探讨电针改善衰老小鼠肝脏脂质代谢的机制。方法: 30周龄雄性SAMP8小鼠随机分为模型组、药物组、电针组,每组7只,以同周龄抗快速老化SAMR1小鼠7只作为对照组。对照组和模型组动物常规饲养4周,不进行任何干预;药物组采用雷帕霉素按(10 mg·kg^-1·d^-1)腹腔注射干预(1次/日,连续每周6 d);电针组予双侧“肾俞”“太冲”穴电针治疗(15 min/次,1次/日,连续每周6 d)。检测小鼠的血清脂质代谢情况、肝脏脂质沉积情况、肝脏自噬体的分布、肝脏LC3-Ⅱ、Beclin1、Atg7、P62蛋白表达与mRNA表达的变化。结果: 与对照组比较,模型组小鼠血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL)显著升高(P＜0.01);模型组肝脏脂滴沉积明显,自噬体减少,自噬相关因子LC3-Ⅱ、Beclin1、Atg7蛋白及mRNA表达水平明显下降(P＜0.01),P62蛋白及mRNA表达水平明显增高(P＜0.01)。与模型组相比,电针组与药物组小鼠血清TG、TC、LDL含量明显降低(P＜0.01);肝脏脂滴沉积减轻,自噬体增多,LC3-Ⅱ、Beclin1、Atg7的蛋白及mRNA表达水平均显著升高(P＜0.01),P62蛋白及mRNA表达水平显著下降(P＜0.01)。电针组肝脏Beclin1、Atg7蛋白及mRNA表达水平均与药物组无明显差异(P＞0.05)。结论: 电针能够减轻肝脏脂质代谢紊乱,可能与调节肝脏自噬相关因子LC3-Ⅱ、Beclin1、Atg7、P62的表达变化,从而促进SAMP8小鼠肝脏自噬有关。

Effects of electroacupuncture on autophagy factors and liver lipid metabolism in rapidly aging mice

Objective: To study the effects of electroacupuncture on the expressions of autophagy-related factors LC3-Ⅱ, Beclin1, Atg7, and P62 in the liver of rapidly aging (senescence accelerated mouse/prone8,SAMP8) mice, and to explore the mechanisms of electroacupuncture to improve liver lipid metabolism in mice. Methods: Thirty-week-old male SAMP8 mice were randomly divided into model group, drug group, and electroacupuncture group, with 7 mice in each group. Seven anti-rapid aging SAMR1 mice of the same age were used as the control group. The animals in the control group and the model group were bred routinely for 2 weeks without any intervention; the drug group was treated with intraperitoneal injection of rapamycin at the dose of 10 mg·kg^-1·d^-1, once a day, 6 consecutive days a week; the electroacupuncture group was given "Shenshu" and "Taichong" Electroacupuncture at point(15 minutes a day, 6 consecutive days a week). The serum lipid metabolism and liver lipid deposition of mice were detected, the distribution of liver autophagy body, the protein and mRNA expressions of liver LC3 - Ⅱ, Beclin1, Atg7 and P62 were determined. Results: Compared with the control group, the total cholesterol (TC), triglycerides (TG), and low density lipoprotein (LDL) of the model group were increased significantly(P＜0.01). In the model group, lipid droplet deposition was obvious, autophagosomes were decreased, the protein and mRNA expression levels of autophagy- related factors LC3-Ⅱ, Beclin1 and Atg7 were decreased significantly (P＜0.01), while the protein and mRNA expressions of P62 were increased significantly (P＜0.01). Compared with the model group, the serum contents of TG, TC, and LDL of the mice in the electroacupuncture group and the drug group were decreased significantly (P＜0.01), lipid droplet deposition was reduced, autophagosomes were increased, the protein and mRNA expression levels of LC3 -Ⅱ, Beclin1 and Atg7 were increased significantly(P＜0.01), and the protein and mRNA expression levels of P62 were decreased significantly(P＜0.01). The protein and mRNA expression levels of Beclin1 and Atg7 in the liver of the electroacupuncture group were not significantly different from the drug group (P＞0.05). Conclusion: Electroacupuncture can alleviate liver lipid metabolism disorders, which may be related to the regulation of the expressions of liver autophagy related factors LC3-Ⅱ, Beclin1, Atg7, and P62, thereby promoting liver autophagy in SAMP8 mice.