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

Abstract

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.