Sun Mengjiao, Wu Xiaoqing, Lin Zhandong, Zhang Congyue, Cui Jiawei, Mao Yaoyao, Shi Yue, Zhang Jiaming, Nan Yuemin
Department of Integrated Traditional Chinese and Western Medicine Hepatology, Hebei Medical University Third Hospital, Shijiazhuang, Hebei, China.
J Clin Transl Hepatol. 2025 Jun 28;13(6):456-468. doi: 10.14218/JCTH.2024.00481. Epub 2025 Mar 12.
Heme oxygenase 1 (HO-1) has an influential yet insufficiently investigated effect on Sirtuin 1 (SIRT1), a histone deacetylase activated by nicotinamide adenine dinucleotide, which may impact the transforming growth factor-β (TGF-ß)/Smad3 pathway in nonalcoholic fatty liver disease (NAFLD)-related liver fibrosis. This study aimed to elucidate the regulation of NAFLD-related liver fibrosis induced by HO-1 through the SIRT1/TGF-ß/Smad3 pathway.
HO-1 induction and inhibition were established in C57BL/6J mice fed a methionine- and choline-deficient (MCD) diet. Additionally, wild-type mice were fed either a normal diet or an MCD diet. Hematoxylin and eosin, Masson's trichrome, and Sirius Red staining were used to assess hepatic steatosis, inflammation, and fibrosis. , plasmid overexpression and small interfering RNA silencing of HO-1 were performed in LX-2 cells. Cell viability was assessed using the Cell Counting Kit-8, and apoptosis was evaluated via terminal deoxynucleotidyl transferase dUTP nick-end labeling and immunofluorescence. Flow cytometry was employed to assess apoptosis and reactive oxygen species production. Western blot and real-time quantitative reverse transcription polymerase chain reaction were used to analyze the mRNA and protein expression of genes related to HO-1, SIRT1, the TGF-ß signaling pathway, and fibrosis.
MCD-fed mice developed significant liver damage, including steatosis, inflammatory infiltration, and pericellular fibrosis. Zinc protoporphyrin treatment exacerbated these conditions. Corroborating these findings, silencing HO-1 in LX-2 cells increased the expression of fibrosis-related genes. Furthermore, HO-1 overexpression not only increased SIRT1 expression but also reduced the activity of key regulatory factors in the TGF-ß signaling pathway, suggesting a potential interaction between HO-1 and the SIRT1/TGF-ß pathway.
HO-1 inhibits the activation of the TGF-ß/Smad3 pathway in NAFLD-related liver fibrosis through SIRT1. These findings provide insights into new therapeutic strategies for treating NAFLD-associated liver fibrosis.
血红素加氧酶1（HO-1）对沉默调节蛋白1（SIRT1）具有重要但尚未充分研究的影响，SIRT1是一种由烟酰胺腺嘌呤二核苷酸激活的组蛋白去乙酰化酶，这可能会影响非酒精性脂肪性肝病（NAFLD）相关肝纤维化中的转化生长因子-β（TGF-β）/Smad3信号通路。本研究旨在阐明HO-1通过SIRT1/TGF-β/Smad3信号通路对NAFLD相关肝纤维化的调控作用。
在喂食蛋氨酸和胆碱缺乏（MCD）饮食的C57BL/6J小鼠中建立HO-1的诱导和抑制模型。此外，野生型小鼠分别喂食正常饮食或MCD饮食。采用苏木精-伊红染色、Masson三色染色和天狼星红染色评估肝脏脂肪变性、炎症和纤维化情况。在LX-2细胞中进行HO-1的质粒过表达和小干扰RNA沉默实验。使用细胞计数试剂盒-8评估细胞活力，并通过末端脱氧核苷酸转移酶dUTP缺口末端标记和免疫荧光评估细胞凋亡。采用流式细胞术评估细胞凋亡和活性氧的产生。使用蛋白质免疫印迹法和实时定量逆转录聚合酶链反应分析与HO-1、SIRT1、TGF-β信号通路和纤维化相关基因的mRNA和蛋白质表达。
喂食MCD饮食的小鼠出现了明显的肝损伤，包括脂肪变性、炎症浸润和细胞周围纤维化。锌原卟啉治疗加剧了这些情况。与这些发现一致，在LX-2细胞中沉默HO-1可增加纤维化相关基因的表达。此外，HO-1过表达不仅增加了SIRT1的表达，还降低了TGF-β信号通路中关键调节因子的活性，提示HO-1与SIRT1/TGF-β信号通路之间可能存在相互作用。
HO-1通过SIRT1抑制NAFLD相关肝纤维化中TGF-β/Smad3信号通路的激活。这些发现为治疗NAFLD相关肝纤维化的新治疗策略提供了见解。
