Department of Hepatobiliary and Pancreatic Surgery, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen 518020, PR China.
Department of Endocrinology, Jingmen First People's Hospital, Jingmen 448000, PR China.
Dig Liver Dis. 2022 Jan;54(1):91-102. doi: 10.1016/j.dld.2021.02.025. Epub 2021 Apr 27.
Hepatic fibrosis is attributed to an imbalance of extracellular matrix production and lysis. Human hepatic stellate cells (HSCs) have been uncovered to converge through complex interactions with hepatocytes and immune cells, causing scarring in liver damage.
We aimed to investigate the expression status of ubiquitin specific peptidase 1 (USP1) and its potential mechanisms on HSCs and hepatic fibrosis.
Hepatic fibrosis animal and cell models were generated using mice with carbon tetrachloride (CCl4) treatment and HSCs LX-2 with TGF-β1 treatment. Relationships among USP1, SNAIL, and CXCL1 were identified via dual-luciferase reporter gene assay, co-immunoprecipitation, and chromatin immunoprecipitation. With gain- and loss-of-experiments, CCK-8 and flow cytometry assays were employed for cell proliferation and apoptosis.
USP1 upregulated SNAIL expression through deubiquitination to increase CXCL1 expression. USP1 downregulation decreased expressions of fibrosis-related genes, suppressed proliferation, and promoted apoptosis in TGF-β1-induced LX-2 cells, which were reversed by SNAIL overexpression. The pro-fibrosis role caused by SNAIL upregulation was abolished by CXCL1 reduction. Promotive function of USP1/SNAIL/CXCL1 axis in hepatic fibrosis was further confirmed in vivo.
These data supported siRNA-mediated silencing of USP1 improved hepatic fibrosis through inhibition of SNAIL and CXCL1, which yields a new therapeutic target for hepatic fibrosis treatment.
肝纤维化归因于细胞外基质产生和溶解的失衡。人类肝星状细胞（HSCs）已被发现通过与肝细胞和免疫细胞的复杂相互作用而趋同，导致肝损伤中的瘢痕形成。
我们旨在研究泛素特异性肽酶 1（USP1）的表达状态及其在 HSCs 和肝纤维化中的潜在机制。
使用四氯化碳（CCl4）处理的小鼠和 TGF-β1 处理的 HSCs LX-2 生成肝纤维化动物和细胞模型。通过双荧光素酶报告基因检测、共免疫沉淀和染色质免疫沉淀鉴定 USP1、SNAIL 和 CXCL1 之间的关系。通过增益和缺失实验，使用 CCK-8 和流式细胞术检测细胞增殖和凋亡。
USP1 通过去泛素化上调 SNAIL 表达，从而增加 CXCL1 的表达。USP1 下调降低了纤维化相关基因的表达，抑制了 TGF-β1 诱导的 LX-2 细胞的增殖，并促进了其凋亡，而过表达 SNAIL 则逆转了这一现象。CXCL1 减少消除了 SNAIL 上调引起的促纤维化作用。USP1/SNAIL/CXCL1 轴在肝纤维化中的促纤维化作用在体内得到进一步证实。
这些数据表明，siRNA 介导的 USP1 沉默通过抑制 SNAIL 和 CXCL1 改善了肝纤维化，为肝纤维化治疗提供了一个新的治疗靶点。
