Liu Linxiang, Li Bimin, Zhang Yue, Nie Yuan, Zhang Wang, Chen Peng, Huang Chenkai, Zhu Xuan
Department of Gastroenterology, Jiangxi Provincial Key Laboratory of Digestive Diseases, Jiangxi Clinical Research Center for Gastroenterology, Digestive Disease Hospital, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, China.
Department of Gastroenterology, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China.
Cell Mol Gastroenterol Hepatol. 2025 May 29:101548. doi: 10.1016/j.jcmgh.2025.101548.
BACKGROUND & AIMS: Liver fibrosis, driven by chronic injury, hinges on hepatic stellate cell (HSC) activation. Microfibrillar-associated protein 4 (MFAP4), an extracellular matrix protein critical for elastic fiber assembly, is up-regulated in hepatic fibrosis, yet its mechanistic role remains unclear.
Liver fibrosis was induced in wild-type and Mfpa4 knockout mice using CCl and TAA, whereas LX-2 cells were activated with transforming growth factor-β1. Bioinformatics analysis, histopathology, double immunofluorescence, flow cytometry, Transwell coculture systems, Western blot, and quantitative polymerase chain reaction were used to identify the primary intrahepatic cell types expressing MFAP4 and assess its effects on HSC activation and apoptosis.
MFAP4 is up-regulated in cirrhotic livers and is actively expressed in HSC. Single-cell RNA sequencing analysis and Transwell coculture experiments revealed that the profibrotic effects of MFAP4 were primarily mediated through HSCs rather than hepatocytes. Inhibition of MFAP4 significantly reduces the expression of fibrosis markers in HSC, inhibits their proliferation and migration, whereas overexpression of MFAP4 results in the opposite effect, accompanied by enhanced apoptosis resistance. In mouse models, global knockout of Mfap4 significantly alleviates CCl- and TAA-induced liver fibrosis. Mechanistic analysis reveals that MFAP4 binds to integrin αvβ3 on the HSC membrane, activating the FAK/PI3K/NFκB signaling pathway, which promotes HSC activation and survival, ultimately exacerbating liver fibrosis. Moreover, MFAP4 mediates a self-sustaining feedback loop via integrin αvβ3, maintaining HSC activation and further promoting fibrosis progression.
MFAP4 governs HSC activation and apoptosis resistance via integrin αvβ3-dependent FAK/PI3K/NFκB signaling. Targeting MFAP4 mitigates fibrosis by altering HSC fate.
肝纤维化由慢性损伤驱动，依赖于肝星状细胞（HSC）的激活。微原纤维相关蛋白4（MFAP4）是一种对弹性纤维组装至关重要的细胞外基质蛋白，在肝纤维化中上调，但其作用机制尚不清楚。
使用四氯化碳（CCl）和硫代乙酰胺（TAA）在野生型和Mfpa4基因敲除小鼠中诱导肝纤维化，而用转化生长因子-β1激活LX-2细胞。采用生物信息学分析、组织病理学、双重免疫荧光、流式细胞术、Transwell共培养系统、蛋白质印迹法和定量聚合酶链反应来鉴定表达MFAP4的主要肝内细胞类型，并评估其对HSC激活和凋亡的影响。
MFAP4在肝硬化肝脏中上调，并在HSC中活跃表达。单细胞RNA测序分析和Transwell共培养实验表明，MFAP4的促纤维化作用主要通过HSC而非肝细胞介导。抑制MFAP4可显著降低HSC中纤维化标志物的表达，抑制其增殖和迁移，而MFAP4的过表达则产生相反的效果，同时伴有抗凋亡能力增强。在小鼠模型中，Mfap4的整体敲除显著减轻了CCl和TAA诱导的肝纤维化。机制分析表明，MFAP4与HSC膜上的整合素αvβ3结合，激活FAK/PI3K/NFκB信号通路，促进HSC激活和存活，最终加剧肝纤维化。此外，MFAP4通过整合素αvβ3介导一个自我维持的反馈环，维持HSC激活并进一步促进纤维化进展。
MFAP4通过整合素αvβ3依赖的FAK/PI3K/NFκB信号调控HSC激活和抗凋亡能力。靶向MFAP4通过改变HSC命运减轻纤维化。
