Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Center of Excellence in Hepatitis and Liver Cancer, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
J Cell Biochem. 2024 Jul;125(7):e30578. doi: 10.1002/jcb.30578. Epub 2024 May 5.
Activation of quiescent hepatic stellate cells (HSCs) into proliferative myofibroblasts drives extracellular cellular matrix (ECM) accumulation and liver fibrosis; nevertheless, the transcriptional network that promotes such a process is not completely understood. ZNF469 is a putative C2H2 zinc finger protein that may bind to specific genome sequences. It is found to be upregulated upon HSC activation; however, the molecular function of ZNF469 is completely unknown. Here, we show that knockdown of ZNF469 in primary human HSCs impaired proliferation, migration, and collagen production. Conversely, overexpression of ZNF469 in HSCs yielded the opposite results. Transforming growth factor-β 1 promoted expression of ZNF469 in a Smad3-dependent manner, where the binding of Smad3 was confirmed at the ZNF469 promoter. RNA sequencing data of ZNF469-knockdown HSCs revealed the ECM-receptor interaction, which provides structural and signaling support to cells, was the most affected pathway, and significant downregulation of various collagen and proteoglycan genes was observed. To investigate the function of ZNF469, we cloned a full-length open reading frame of ZNF469 with an epitope tag and identified a nuclear localization of the protein. Luciferase reporter and chromatin immunoprecipitation assays revealed the presence of ZNF469 at the promoter of ECM genes, supporting its function as a transcription factor. Analysis of human fibrotic and cirrhotic tissues showed increased expression of ZNF469 and a positive correlation between expression levels of ZNF469 and ECM genes. Moreover, this observation was similar in other fibrotic organs, including the heart, lung, and skin, suggesting that myofibroblasts from various origins generally require ZNF469 to promote ECM production. Together, this study is the first to reveal the role of ZNF469 as a profibrotic factor in HSCs and suggests ZNF469 as a novel target for antifibrotic therapy.
静止的肝星状细胞(HSCs)被激活为增殖性肌成纤维细胞,导致细胞外基质(ECM)积累和肝纤维化;然而,促进这一过程的转录网络尚未完全被理解。ZNF469 是一种假定的 C2H2 锌指蛋白,可能与特定的基因组序列结合。研究发现,ZNF469 在 HSC 激活时上调;然而,ZNF469 的分子功能完全未知。在这里,我们表明,在原代人 HSCs 中敲低 ZNF469 会损害增殖、迁移和胶原产生。相反,在 HSCs 中过表达 ZNF469 则产生相反的结果。转化生长因子-β 1(TGF-β1)以 Smad3 依赖的方式促进 ZNF469 的表达,在 ZNF469 启动子处确认了 Smad3 的结合。ZNF469 敲低 HSCs 的 RNA 测序数据显示,细胞外基质受体相互作用是受影响最严重的途径,为细胞提供结构和信号支持,并且观察到各种胶原和蛋白聚糖基因的显著下调。为了研究 ZNF469 的功能,我们克隆了带有表位标签的全长开放阅读框,并鉴定了该蛋白的核定位。荧光素酶报告基因和染色质免疫沉淀检测显示 ZNF469 存在于 ECM 基因的启动子上,支持其作为转录因子的功能。对人类纤维化和肝硬化组织的分析表明 ZNF469 表达增加,并且 ZNF469 表达水平与 ECM 基因之间呈正相关。此外,在其他纤维化器官(包括心脏、肺和皮肤)中也观察到类似的现象,这表明来自不同来源的肌成纤维细胞通常需要 ZNF469 来促进 ECM 产生。总之,这项研究首次揭示了 ZNF469 作为 HSCs 中促纤维化因子的作用,并提示 ZNF469 可作为抗纤维化治疗的新靶点。