DataSheet1_Electroacupuncture induces weight loss by regulating tuberous sclerosis complex 1-mammalian target of rapamycin methylation and hypothalamic autophagy in high-fat diet-induced obese rats.PDF

Background: Obesity can be caused by abnormalities of hypothalamic autophagy, which is closely regulated by the epigenetic modification of TSC1-mTOR. However, whether the weight-reducing effect of EA may relate to the modification of TSC1-mTOR methylation and hypothalamic autophagy remain unclear. This study was conducted to reveal the possible mechanism by which EA reduces BW by measuring the levels of TSC1-mTOR methylation and hypothalamic autophagy-related components.
Methods: The weight-reducing effect of EA was investigated in high-fat diet (HFD)-induced obese (DIO) rats by monitoring the BW, food consumption, and epididymal white adipose tissue (eWAT)/BW ratio. Hematoxylin and eosin staining was performed for morphological evaluation of eWAT. Immunofluorescence was utilized to observe the localization of LC3 in the hypothalamus. The expressions of autophagy components (Beclin-1, LC3, and p62) and mTOR signaling (mTOR, p-mTOR, p70S6K, and p-p70S6K) were assessed by western blot. The methylation rate of the TSC1 promoter was detected by bisulfite genomic sequencing.
Results: Treatment with EA significantly reduced the BW, food consumption, and eWAT/BW ratio; attenuated the morphological alternations in the adipocytes of DIO rats. While HFD downregulated the expression levels of Beclin-1 and LC3 and upregulated those of p62, these changes were normalized by EA treatment. EA markedly decreased the methylation rate of the TSC1 gene promoter and suppressed the protein expressions of mTOR, p-mTOR, p70S6K, and p-p70S6K in the hypothalamus.
Conclusion: EA could reduce BW and fat accumulation in DIO rats. This ameliorative effect of EA may be associated with its demethylation effect on TSC1-mTOR and regulation of autophagy in the hypothalamus.

背景：下丘脑自噬异常可诱发肥胖，其调控过程与TSC1-mTOR的表观遗传修饰密切相关。目前尚不清楚电针（EA）的减重效应是否与TSC1-mTOR甲基化修饰及下丘脑自噬有关。本研究通过检测TSC1-mTOR甲基化水平及下丘脑自噬相关蛋白组分，旨在揭示电针减轻体重（BW）的潜在作用机制。
方法：本研究以高脂饮食（HFD）诱导的肥胖（DIO）大鼠为模型，通过监测体重（BW）、食物摄入量及附睾白色脂肪组织（eWAT）/体重比值，探究电针的减重效应。采用苏木精-伊红染色对附睾白色脂肪组织进行形态学评估。利用免疫荧光技术观察LC3在大鼠下丘脑的定位情况。通过蛋白质印迹法（western blot）检测自噬相关蛋白（Beclin-1、LC3、p62）及mTOR信号通路相关蛋白（mTOR、磷酸化mTOR（p-mTOR）、p70S6激酶（p70S6K）、磷酸化p70S6激酶（p-p70S6K））的表达水平。采用亚硫酸氢盐基因组测序法检测TSC1基因启动子的甲基化率。
结果：电针干预可显著降低大鼠体重、食物摄入量及附睾白色脂肪组织/体重比值，并改善高脂饮食诱导肥胖大鼠脂肪细胞的形态学异常。高脂饮食可下调Beclin-1与LC3的表达水平，上调p62的表达，而电针干预可使上述变化恢复至正常水平。此外，电针可显著降低TSC1基因启动子的甲基化率，并抑制大鼠下丘脑内mTOR、磷酸化mTOR、p70S6激酶及磷酸化p70S6激酶的蛋白表达。
结论：电针可减轻高脂饮食诱导肥胖大鼠的体重及脂肪堆积。其改善作用可能与调控TSC1-mTOR的去甲基化修饰及下丘脑自噬通路有关。