目的 基于腺苷酸活化蛋白激酶（adenosine monophosphate-activated protein kinase，AMPK）/沉默信息调节因子1（silent information regulator 1，SIRT1）/肝X受体（liver X receptors，LXRs）信号通路探究垂盆草提取物Sedum sarmentosum改善肝纤维化的作用机制。方法 采用ip二甲基亚硝胺（dimethylnitrosamine，DMN）建立大鼠肝纤维化模型，给予垂盆草提取物或扶正化瘀胶囊干预5周后，收集血清和肝组织。检测血清中丙氨酸氨基转移酶（alanine aminotransferase，ALT）和天冬氨酸氨基转移酶（aspartate aminotransferase，AST）活性；苏木素-伊红（hematoxylin-eosin，HE）和Masson染色检测肝组织病理变化；采用免疫组化、Western blotting和qRT-PCR检测肝组织纤维化、凋亡、炎症、AMPK-SIRT1-LXRs信号通路相关蛋白和基因表达。采用转化生长因子-β（transforming growth factor-β，TGF-β）刺激肝星状细胞（hepatic stellate cells，HSCs）2 h，给予垂盆草提取物或AMPK激动剂AICAR或LXRβ激动剂GW3965处理6 h，采用免疫荧光染色和Western blotting检测纤维化、AMPK/SIRT1/LXRs信号通路相关蛋白表达。使用AMPK或LXRβ siRNA转染LX-2细胞后，给予TGF-β刺激2 h，再加入垂盆草处理6 h，采用Western blotting检测AMPK/SIRT1/LXRs信号通路相关蛋白表达。结果 体内实验结果显示，垂盆草提取物显著降低DMN诱导的大鼠血清中ALT和AST活性（P＜0.001），改善肝组织病理学改变和细胞外基质沉积，抑制肝组织细胞凋亡和炎症因子表达（P＜0.001），上调AMPK-SIRT1-LXRs信号通路相关蛋白表达（P＜0.05、0.01、0.001）。体外实验结果显示，垂盆草提取物显著抑制活化的HSCs中细胞外基质相关蛋白表达（P＜0.001），并上调AMPK/SIRT1/LXRs信号通路相关蛋白表达（P＜0.001），作用效果与AMPK激动剂或LXRβ激动剂相似。此外，AMPK或LXRβ的缺失显著削弱了垂盆草提取物对活化的LX-2细胞中α-平滑肌细胞肌动蛋白（α-smooth muscle actin，α-SMA）的抑制以及对AMPK/SIRT1/LXRs信号通路的激活（P＜0.001）。结论 垂盆草提取物通过介导AMPK/SIRT1/LXRs信号通路，调控细胞外基质稳态和炎症反应，有效改善肝纤维化进程。

Objective To explore the mechanism of Sedum sarmentosum extract in improving liver fibrosis based on adenosine monophosphate-activated protein kinase (AMPK)/silent information regulator 1 (SIRT1)/liver X receptors (LXRs) signaling pathway. Methods A rat model of liver fibrosis was established using ip dimethylnitrosamine (DMN), and after intervention with S. sarmentosum extract or Fuzheng Huayu Capsules (扶正化瘀胶囊) for five weeks, serum and liver tissue were collected. The activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum were determined. Hematoxylin-eosin (HE) and Masson staining were used to detect pathological changes in liver tissue. Immunohistochemistry, Western blotting and qRT-PCR were used to detect fibrosis, apoptosis, inflammation, AMPK/SIRT1/LXRs signaling pathway related proteins and gene expressions in liver tissue. Transforming growth factor-β (TGF-β) was used to stimulate hepatic stellate cells (HSCs) for 2 h, followed by treatment with S. sarmentosum extract or AMPK agonist AICAR or LXRβ agonist GW3965 for 6 h. Immunofluorescence staining and Western blotting were used to detect the expressions of fibrosis and AMPK-SIRT1-LXRs signaling pathway related proteins. After transfecting LX-2 cells with AMPK or LXRβ siRNA, TGF-β stimulation was given for 2 h, followed by treatment with S. sarmentosum extract for 6 h. Western blotting was used to detect the expressions of AMPK/SIRT1/LXRs signaling pathway related proteins. Results The results of in vivo experiments showed that S. sarmentosum extract significantly reduced the activities of ALT and AST in serum of rats induced by DMN (P < 0.001), improved pathological changes and extracellular matrix deposition in liver tissue, inhibited cell apoptosis and inflammatory factor expressions in liver tissue (P < 0.001), and upregulated the expressions of AMPK/SIRT1/LXRs signaling pathway related proteins (P < 0.05, 0.01, 0.001). The in vitro experimental results showed that S. sarmentosum extract significantly inhibited the expressions of extracellular matrix related proteins in activated HSCs (P < 0.001), and upregulated the expressions of AMPK-SIRT1-LXRs signaling pathway related proteins (P < 0.001), with similar effects as AMPK agonists or LXRβ agonists. In addition, the absence of AMPK or LXRβ significantly weakened the inhibition of α-smooth muscle actin (α-SMA) in activated LX-2 cells and the activation of AMPK/SIRT1/LXRs signaling pathway by S. sarmentosum extract (P < 0.001). Conclusion S. sarmentosum extract effectively improves the progression of liver fibrosis by mediating AMPK/SIRT1/LXRs signaling pathway, to regulate extracellular matrix homeostasis and inflammatory responses.

R285.5

国家自然科学基金资助项目（82560813）；延边大学2026年度大学生创新创业训练计划项目（202610184021）