Ding Rongrong, Zheng Jianming, Li Ning, Cheng Qi, Zhu Mengqi, Wang Yanbing, Zhou Xinlan, Zhang Zhanqing, Shi Guangfeng
Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China.
Hepatobiliary Medicine, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China.
PeerJ. 2021 May 14;9:e11374. doi: 10.7717/peerj.11374. eCollection 2021.
Hepatic fibrosis is a common response to chronic liver injury. Recently, the role of DZNep (a histone methyltransferase EZH2 inhibitor) in repressing pulmonary and renal fibrosis was verified. However, the potential effect of DZNep on hepatic fibrosis has not been elucidated.
The hepatic fibrosis model was established in rats treated with CCl4 and in hepatic stellate cells (HSCs) treated with TGF-1. The liver tissues were stained with H&E and Masson's trichrome. The expression of EZH2, SOCS7, collagen I, SMA mRNA and miR-199-5p was assessed using qPCR, immunohistochemical or western blot analysis. A dual-luciferase reporter assay was carried out to validate the regulatory relationship of miR-199a-5p with SOCS7.
The EZH2 level was increased in CCl4-treated rats and in TGF-1-treated HSCs, whereas DZNep treatment significantly inhibited EZH2 expression. DZNep repressed hepatic fibrosis in vivo and in vitro, as evidenced by the decrease of hepatic fibrosis markers (-SMA and Collagen I). Moreover, miR-199a-5p expression was repressed by DZNep in TGF-1-activated HSCs. Notably, downregulation of miR-199a-5p decreased TGF-1-induced expression of fibrosis markers. SOCS7 was identified as a direct target of miR-199a-5p. The expression of SOCS7 was decreased in TGF-1-activated HSCs, but DZNep treatment restore d SOCS7 expression. More importantly, SOCS7 knockdown decreased the effect of DZNep on collagen I and SMA expression in TGF-1-activated HSCs.
DZNep suppresses hepatic fibrosis through regulating miR-199a-5p/SOCS7 axis, suggesting that DZNep may represent a novel treatment for fibrosis.
肝纤维化是慢性肝损伤的常见反应。最近，已证实DZNep（一种组蛋白甲基转移酶EZH2抑制剂）在抑制肺和肾纤维化中的作用。然而，DZNep对肝纤维化的潜在影响尚未阐明。
在用四氯化碳处理的大鼠和用转化生长因子-1处理的肝星状细胞（HSCs）中建立肝纤维化模型。肝组织用苏木精和伊红染色以及Masson三色染色。使用qPCR、免疫组织化学或蛋白质印迹分析评估EZH2、SOCS7、I型胶原蛋白、平滑肌肌动蛋白mRNA和miR-199-5p的表达。进行双荧光素酶报告基因测定以验证miR-199a-5p与SOCS7的调控关系。
在四氯化碳处理的大鼠和转化生长因子-1处理的HSCs中，EZH2水平升高，而DZNep处理显著抑制EZH2表达。DZNep在体内和体外均抑制肝纤维化，肝纤维化标志物（α-平滑肌肌动蛋白和I型胶原蛋白）的减少证明了这一点。此外，在转化生长因子-1激活的HSCs中，DZNep抑制了miR-199a-5p的表达。值得注意的是，miR-199a-5p的下调降低了转化生长因子-1诱导的纤维化标志物的表达。SOCS7被确定为miR-199a-5p的直接靶标。在转化生长因子-1激活的HSCs中，SOCS7的表达降低，但DZNep处理恢复了SOCS7的表达。更重要的是,SOCS7基因敲低降低了DZNep对转化生长因子-1激活的HSCs中I型胶原蛋白和平滑肌肌动蛋白表达的影响。
DZNep通过调节miR-199a-5p/SOCS7轴抑制肝纤维化，表明DZNep可能代表一种治疗纤维化的新方法
