黑茶水提物通过介导AMPK/mTOR信号通路调控自噬干预非酒精性脂肪肝的机制研究

doi:10.13305/j.cnki.jts.2024.02.012

摘要/Abstract

摘要： 为探讨安化黑茶水提物对高脂高糖（HFHS）饮食诱导的非酒精性脂肪肝病（NAFLD）小鼠调控自噬改善脂肪变性的作用机制,将雄性C57BL/6J小鼠分为正常组、模型组、西药组（10 mg·kg^-1）、黑茶低剂量组（0.75 g·kg^-1）、中剂量组（1.5 g·kg^-1）、高剂量组（3.0 g·kg^-1）。采用HFHS饮食诱导小鼠NAFLD模型,造模的同时灌胃给药10周;试验结束后检测小鼠的肝指数、血脂、肝功能、肝脏病理指标、自噬指标及自噬相关信号通路表达水平。结果表明,与正常组相比,模型组小鼠肝指数和总胆固醇（CHO）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）、谷草转氨酶（AST）、谷丙转氨酶（ALT）含量显著升高,高密度脂蛋白胆固醇（HDL-C）含量明显降低;小鼠肝脏出现了脂肪变性的迹象,伴有大量大小不一的脂滴;微管相关蛋白1轻链3B（LC3B）、Bcl-2相互作用蛋白1（Beclin1）、磷酸化腺苷酸活化蛋白激酶/腺苷酸活化蛋白激酶（p-AMPK/AMPK）表达明显降低,隔离体蛋白1（p62）、磷酸化哺乳动物雷帕霉素靶蛋白/哺乳动物雷帕霉素靶蛋白（p-mTOR/mTOR）表达显著上升。与模型组相比,灌胃黑茶水提物可降低NAFLD小鼠肝指数和血清CHO、TG、LDL-C、AST、ALT水平,以及p62、p-mTOR/mTOR蛋白表达水平,升高血清HDL-C含量,以及LC3B、Beclin1、p-AMPK/AMPK蛋白表达水平;组织染色结果和透射电镜观察均表明肝脏的病理状态得到了改善。综上所述,黑茶水提物可能通过激活AMPK/mTOR信号通路调控自噬,减轻小鼠肝脏脂肪变性,从而改善NAFLD。

关键词: 非酒精性脂肪肝病, 黑茶, AMPK/mTOR, 自噬

Abstract: This study aimed to investigate the intricate mechanisms underlying the modulatory effects of Anhua dark tea on autophagy to ameliorate steatosis induced by a high-fat and high-sucrose diet (HFHS) in mice with non-alcoholic fatty liver disease (NAFLD). Male C57BL/6J mice were divided into different groups, including a normal group, a model group, a Western medicine group (10 mg·kg^-1), and various doses of dark tea groups (0.75, 1.5, 3.0 g·kg^-1). The therapeutic regimen was administered concurrently with the modeling process for a duration of 10 weeks using the HFHS-induced NAFLD model. At the end of the experiment, liver indices, blood lipids, liver function, liver pathology indicators, autophagy markers, and expression levels of key genes in the autophagy-related signaling pathway were assessed. Comparative analyses with the normal group revealed significant increases in liver index and levels of serum cholesterol (CHO), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), aspartate aminotransferase (AST), and alanine aminotransferase (ALT), as well as a substantial reduction in high-density lipoprotein cholesterol (HDL-C) levels in the model group. The liver of the mice exhibits signs of steatosis, characterized by an abundance of lipid droplets of different sizes. Protein expression analysis reveals a marked decrease in the levels of microtubule-associated protein light-chain-3B (LC3B), Bcl-2-interacting coiled-coil protein 1 (Beclin1), and phosphorylated adenosine monophosphate-activated protein kinase/adenosine monophosphate-activated protein kinase (p-AMPK/AMPK). Conversely, there was a significant increase in the levels of sequestosome-1 (p62) and phosphorylated mammalian target of rapamycin/mammalian target of rapamycin (p-mTOR/mTOR). Compared to the model group, gavage with dark tea decreased the liver index, serum levels of CHO, TG, LDL-C, AST, ALT, p62, and p-mTOR/mTOR in NAFLD mice, and increased serum HDL-C, along with LC3B, Beclin1, and p-AMPK/AMPK protein levels. The improvements were confirmed by tissue staining results and observations using transmission electron microscopy. In summary, our findings suggest that dark tea, by activating the AMPK/mTOR signaling pathway, may regulate autophagy, thereby alleviating hepatic steatosis and improving non-alcoholic fatty liver disease (NAFLD).

Key words: nonalcoholic fatty liver disease, dark tea, AMPK/mTOR, autophagy

中图分类号:

李琳莉, 夏旭婷, 施敏, 葛俊, 毛彩薇, 喻长红, 刘富林. 黑茶水提物通过介导AMPK/mTOR信号通路调控自噬干预非酒精性脂肪肝的机制研究[J]. 茶叶科学, 2024, 44(2): 329-340. doi: 10.13305/j.cnki.jts.2024.02.012.

LI Linli, XIA Xuting, SHI Min, GE Jun, MAO Caiwei, YU Changhong, LIU Fulin. Mechanism of Dark Tea Water Extract in Regulating Autophagy in Non-Alcoholic Fatty Liver via the AMPK/mTOR Signaling Pathway[J]. Journal of Tea Science, 2024, 44(2): 329-340. doi: 10.13305/j.cnki.jts.2024.02.012.

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