电针通过肝脏中TLR4/NF-κB炎症通路改善肥胖诱导的胰岛素抵抗的机制

[Mechanisms of electroacupuncture in improving obesity-induced insulin resistance via TLR4/NF-κB inflammatory pathway in liver].

作者信息

Lu Wei, Wu Song, Li Jia, Wang Ya-Yuan, Zhou Yu-Dian, Liang Feng-Xia

机构信息

Clinical College of Chinese Medicine, Hubei University of Chinese Medicine, Wuhan 430061, China; Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan 430061.

College of Acupuncture and Orthopedics, Hubei University of Chinese Medicine, Wuhan 430061; Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan 430061.

出版信息

Zhen Ci Yan Jiu. 2022 Jun 25;47(6):504-9. doi: 10.13702/j.1000-0607.20210362.

DOI:10.13702/j.1000-0607.20210362

PMID:35764517

Abstract

OBJECTIVE

To investigate the effect of electroacupuncture (EA) on the Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) inflammatory pathway in the liver of obese rats with insulin resistance, and explore its mechanism.

METHODS

Male Wistar rats were randomly divided into a normal group (=15) and an experimental group (=30). The obesity-induced insulin resistance model was induced by the high-fat diet (HFD) in rats of the experimental group for 8 weeks. Subsequently, the model rats were further divided into a model group (=15) and an EA group (=15). EA was applied at "Zhongwan "(CV12), "Guanyuan" (CV4), "Zusanli "(ST36) and "Fenglong "(ST40) in the EA group for 10 min, three times a week for 8 weeks. The body weight of rats in each group was measured before intervention and at the 2nd, 4th, 6th, and 8th weeks during the intervention. Glucose infusion rate (GIR) was measured by glucose clamp test before and after treatment. After treatment, fast blood glucose (FBG) was detected by the glucometer, and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. The contents of fasting insulin (FINS), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were determined by ELISA. The protein expressions of TLR4, IκB kinase β (IKKβ), phosphorylated IKKβ (p-IKKβ), NF-κB p65, and TNF-α related to the TLR4/NF-κB signaling pathway in the liver of rats were detected by Western blot.

RESULTS

Compared with the normal group, the body weight, HOMA-IR levels, serum levels of FINS, TNF-α, and IL-6 were up-regulated (<0.01), and the GIR level was down-regulated (<0.01), the protein expressions of TLR4, IKKβ, p-IKKβ, NF-κB p65 and TNF-α in liver tissues were increased(<0.05) in the model group. Compared with the model group, the EA group showed weight loss from the 6th week, and the HOMA-IR levels，serum levels of FINS, TNF-α, and IL-6 were decreased(<0.01, <0.05), the GIR level was up-regulated (<0.01), the protein expressions of TLR4, IKKβ, p-IKKβ, NF-κB p65 and TNF-α in liver tissues were down-regulated (<0.05).

CONCLUSION

EA can reduce the inflammatory response and improve peripheral insulin sensitivity by inhibiting the TLR4/NF-κB pathway in liver tissues of obese rats with insulin resistance, showing a good regulatory effect on insulin resistance induced by obesity.

摘要

目的

探讨电针（EA）对胰岛素抵抗肥胖大鼠肝脏中Toll样受体4（TLR4）/核因子κB（NF-κB）炎症通路的影响，并探究其作用机制。

方法

雄性Wistar大鼠随机分为正常组（n = 15）和实验组（n = 30）。实验组大鼠采用高脂饮食（HFD）诱导肥胖性胰岛素抵抗模型8周。随后，将模型大鼠进一步分为模型组（n = 15）和电针组（n = 15）。电针组在“中脘”（CV12）、“关元”（CV4）、“足三里”（ST36）和“丰隆”（ST40）穴位施针10分钟，每周3次，共8周。测量每组大鼠干预前及干预期间第2、4、6和8周的体重。治疗前后通过葡萄糖钳夹试验测量葡萄糖输注率（GIR）。治疗后，用血糖仪检测空腹血糖（FBG），并计算胰岛素抵抗稳态模型评估值（HOMA-IR）。采用酶联免疫吸附测定法（ELISA）测定空腹胰岛素（FINS）、肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）的含量。通过蛋白质免疫印迹法（Western blot）检测大鼠肝脏中与TLR4/NF-κB信号通路相关的TLR4、IκB激酶β（IKKβ）、磷酸化IKKβ（p-IKKβ）、NF-κB p65和TNF-α的蛋白表达。

结果

与正常组相比，模型组大鼠体重、HOMA-IR水平、血清FINS、TNF-α和IL-6水平上调（P < 0.01），GIR水平下调（P < 0.01），肝组织中TLR4、IKKβ、p-IKKβ、NF-κB p65和TNF-α的蛋白表达增加（P < 0.05）。与模型组相比，电针组从第6周开始体重减轻，HOMA-IR水平、血清FINS、TNF-α和IL-6水平降低（P < 0.01，P < 0.05），GIR水平上调（P < 0.01），肝组织中TLR4、IKKβ、p-IKKβ、NF-κB p65和TNF-α的蛋白表达下调（P < 0.05）。