肝星状细胞（HSCs）激活后分化为肌成纤维细胞并分泌细胞外基质（ECM）。此过程在肝纤维化的发展中至关重要。但活化并维持HSCs成纤维表型的分子机制不完全明确。研究表明，机械力-细胞内信号转导分子YAP-1在促纤维细胞活化中有重要作用。我们发现，YAP-1在肝纤维化组织和活化的HSCs中持续高表达；YAP-1入核上调CTGF转录对维持HSCs分化有重要意义。本课题拟：建立HSCs的悬浮、2D及3D-Organoids细胞培养模型，探讨微环境硬度对YAP-1的调控作用；通过CRISPR/Cas9、免疫共沉淀等技术，阐述YAP-1/CTGF通路在HSCs-ECM相互调控中的机制；在基因敲除小鼠中验证靶向YAP-1治疗肝纤维化的效果。本项目旨在明确YAP-1在HSCs活化过程中的分子作用和YAP-1/CTGF通路维持HSCs分化的反馈环路，为揭示肝纤维化的发病机制和治疗新靶点提供新的见解。

Activation of hepatic stellate cells (HSCs) into myofibroblasts characterized by enhanced extracellular matrix (ECM) production is well established as the central driver of liver fibrosis. However, the molecular mechanisms underlying the activation and maintenance of the myofibroblastic HSCs phenotypes are still not fully understood. It was reported that YAP-1 as the mediator of mechanotransduction was the key coordinator of fibroblasts activation. In pilot experiments, we found that YAP-1 sustained high expression in both fibrotic human liver tissues and activated HSCs. Moreover, YAP-1 was activated and translocated into the nucleus driving the expression of its target gene-CTGF, which has essential function in maintaining the transdifferentiation of HSCs. In the project, we plan to investigate the role of extracellular stiffness in modulating YAP-1 expression by establishing cell culture models of suspension, 2D, and 3D-Organoids for HSCs. Secondly, we try to reveal the mechanism of YAP-1/CTGF signaling in regulating the interactive effects between HSCs and ECM via CRISPR/Cas9-based knock-out and co-immunoprecipitation methods. Last but not least, in vivo experiments will be performed in gene knock-out mice models to assess the antifibrotic efficacy by targeting YAP-1. In summary, we aim to uncover if YAP-1 represents a crucial initiator and maintainer in the process of HSCs activation and investigate the feedback loop of YAP-1/CTGF signaling pathway in sustaining the activation process. These results may contribute to revealing the pathogenesis of liver fibrosis and highlighting the translational significance by novel therapeutic targets.