School of Life Science, Shaoxing University, Shaoxing, China.
Department of Pathology, Affliliated Hospital of Shaoxing University, Shaoxing, China.
Am J Physiol Gastrointest Liver Physiol. 2021 May 1;320(5):G720-G728. doi: 10.1152/ajpgi.00310.2020. Epub 2021 Mar 17.
The Hedgehog (Hh) signaling pathway is correlated with hepatic stellate cells (HSCs) activation and liver fibrosis. is a key transcription effector of Hh signaling. However, the role of in HSC-mediated liver fibrosis progression is largely unknown. In the present study, we investigated the effect of on liver fibrogenesis and its possible mechanism using conditional knockout (cKO) mice and HSC models. Wild-type (WT) and ; male mice were exposed to CCl for 1 mo to induce liver fibrosis. Primary HSCs were isolated from mice and the transition of HSCs into a myofibroblastic phenotype was evaluated. Livers from mice underwent histological, immunohistochemical, and immunofluorescence analyses. The expression levels of proteins and genes were evaluated by Western blot (WB) analysis and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. RNA-seq was used to screen differentially expressed genes. Results showed that CCl treatment induced liver fibrosis, promoted HSCs activation and proliferation, and upregulated Hh signaling activity. The cKO of in ; mice decreased liver fibrosis as well as HSC activation and proliferation. In vitro studies showed that KO of in HSCs blocked cell proliferation and activation by decrease of cyclin D1/D2 expression. The RNA-seq results revealed that the expression levels ligands were downregulated in KO HSCs. Furthermore, overexpression of rescued proliferation and activation of HSCs by upregulation of TGF-β signaling activity. Our data demonstrated that regulated HSC activation and liver fibrosis by TGF-β signaling, thus providing support for future Gli2-based investigations of liver fibrosis therapy. is a key transcription effector of Hh signaling. We found that Hh/Gli2 signaling activity was upregulated in CCl-induced liver fibrosis. Conditional deletion of the gene in HSCs ameliorated CCl-induced liver fibrosis and HSCs activation. Moreover, promoted activation of HSCs through upregulation of cyclin expression and TGF-β signaling activity. Thus, our data provide strong support for future investigations on inhibition to slow liver fibrosis progression in humans.
Hedgehog (Hh) 信号通路与肝星状细胞 (HSCs) 的激活和肝纤维化有关。Gli2 是 Hh 信号的关键转录效应因子。然而，Gli2 在 HSCs 介导的肝纤维化进展中的作用在很大程度上尚不清楚。在本研究中，我们使用条件敲除 (cKO) 小鼠和 HSC 模型研究了 Gli2 对肝纤维化形成的影响及其可能的机制。野生型 (WT) 和 ; 雄性小鼠暴露于 CCl4 1 个月以诱导肝纤维化。从小鼠中分离原代 HSCs，并评估 HSCs 向肌成纤维细胞表型的转化。对小鼠的肝脏进行组织学、免疫组织化学和免疫荧光分析。通过 Western blot (WB) 分析和定量实时聚合酶链反应 (qRT-PCR) 分别评估蛋白质和基因的表达水平。RNA-seq 用于筛选差异表达基因。结果表明，CCl4 处理诱导肝纤维化，促进 HSCs 激活和增殖，并上调 Hh 信号活性。; 小鼠中 Gli2 的 cKO 降低了肝纤维化以及 HSCs 的激活和增殖。体外研究表明，HSCs 中 Gli2 的 KO 通过下调细胞周期蛋白 D1/D2 的表达来阻断细胞增殖和激活。RNA-seq 结果显示，Gli2 KO HSCs 中Gli2 配体的表达水平下调。此外，TGF-β 信号活性的上调挽救了 HSCs 的增殖和激活。我们的数据表明，Gli2 通过 TGF-β 信号调节 HSCs 的激活和肝纤维化，从而为未来基于 Gli2 的肝纤维化治疗研究提供支持。Gli2 是 Hh 信号的关键转录效应因子。我们发现，CCl4 诱导的肝纤维化中 Hh/Gli2 信号活性上调。HSCs 中Gli2 基因的条件缺失改善了 CCl4 诱导的肝纤维化和 HSCs 激活。此外，Gli2 通过上调 cyclin 表达和 TGF-β 信号活性促进 HSCs 的激活。因此，我们的数据为未来研究抑制 Gli2 以减缓人类肝纤维化进展提供了有力支持。
