HIF-1α/LTBP2 axis activate HSCs to promote liver fibrosis by interacting with LOXL1 via the ERK pathway

作者：Mengxin Lü, Shuai Tao, Conglin Zhao, Neng Wang, Qiankun Hu, Qiang Li, Xun Qi, Xinyan Li, Yi Zhang, Chuantao Tu, Yuxian Huang, Liang Chen · 发表于：Cellular and Molecular Life Sciences · 年份：2025 · DOI：10.1007/s00018-025-05682-0 · 被引用次数：9 · 研究领域：Microbial metabolism and enzyme function、Lipid metabolism and disorders、Liver Disease Diagnosis and Treatment

Latent Transforming Growth Factor Beta Binding Protein 2 (LTBP2) is a multi-domain exocrine protein located in the extracellular matrix (ECM) and has been implicated in fibrosis across various organs. However, its role in liver fibrosis remains inadequately understood. This study aims to elucidate the function and mechanism of LTBP2 in hepatic stellate cells (HSCs) activation and liver fibrosis. Our findings indicate that LTBP2 expression is positively correlated with liver fibrosis and is significantly elevated in fibrotic liver tissues from both human and murine models. Importantly, AAV6-mediated knockdown of LTBP2 in HSCs markedly alleviates CCl4-induced liver fibrosis by inhibiting the HSCs activation and reducing collagen deposition in mice. Gain-of-function and loss-of-function experiments confirmed that overexpression or knockdown of LTBP2 can enhance or inhibit the activation of HSCs, proliferation, migration and epithelial-mesenchymal transition (EMT) in LX-2 cells. Mechanistically, chromatin immunoprecipitation (ChIP) assays and dual-luciferase reporter gene assays revealed that Hypoxia-inducible Factor 1α (HIF-1α) promotes LTBP2 expression by directly binding to the LTBP2 promoter region. Furthermore, molecular docking and co-immunoprecipitation (Co-IP) experiments demonstrated an interaction between Lysyl Oxidase Like Protein 1 (LOXL1) and LTBP2. Rescue experiments verified that LTBP2 interacts with LOXL1 via the ERK signaling pathway to promote the activation of ...