TGF-\u03b2-induced hepatocyte lincRNA-p21 contributes to liver fibrosis in mice

Xiaolong Tu,Zhen Huang,Huanan Li,Zhipeng Cao,Yuhui Zang,Zhiqian Kang,Zhi Ding,Yuanyuan Zhang,Junfeng Zhang,Jia Deng,Jiangning Chen,Xiuxiu Zheng,Lei Dong

doi:10.1038/s41598-017-03175-0

Abstract

Hepatocyte death, as well as the following inflammatory and fibrogenic signaling cascades, is the key trigger of liver fibrosis. Here, we isolated hepatocytes from CCl4-induced fibrotic liver and found that hepatocyte lincRNA-p21 significantly increased during liver fibrosis. The increase of hepatocyte lincRNA-p21 was associated with the loss of miR-30, which can inhibit TGF-β signaling by targeting KLF11. We revealed that lincRNA-p21 modulated miR-30 availability by acting as a competing endogenous RNA (ceRNA). The physiological significance of this interaction is highlighted by the feedback loop, in which lincRNA-p21 works as a downstream effector of the TGF-β signaling to strengthen TGF-β signaling and mediate its role in promoting liver fibrosis by interacting with miR-30. In vivo results showed that knockdown of hepatocyte lincRNA-p21 greatly reduced CCl4-induced liver fibrosis and inflammation, whereas ectopic expression of miR-30 in hepatocyte exhibited the similar results. Mechanistic studies further revealed that inhibition of miR-30 impaired the effects of lincRNA-p21 on liver fibrosis. Additionally, lincRNA-p21 promoted hepatocyte apoptosis in vitro and in vivo, whereas the proliferation rate of hepatocyte was suppressed by lincRNA-p21. The pleiotropic roles of hepatocyte lincRNA-p21 suggest that it may represent an unknown paradigm in liver fibrosis and serve as a potential target for therapy.

Highlights

Hepatic fibrosis occurs during most chronic liver diseases and is characterized by the excessive production of extracellular matrix (ECM)[1, 2]
Among the highly expressed Long noncoding RNAs (lncRNAs), we focused on the intergenic lncRNA-p21, which was initially identified as a transcriptional target of p53
We examined the lincRNA-p21 expression in the fibrotic liver and isolated hepatic stellate cells (HSCs) and found that hepatic lincRNA-p21 increased after CCl4-treatment

Summary

Introduction

Hepatic fibrosis occurs during most chronic liver diseases and is characterized by the excessive production of extracellular matrix (ECM)[1, 2]. We find that hepatocyte lincRNA-p21 can function as a ceRNA by binding miR-30, and participating in the regulation of TGF-β signaling and liver fibrosis. To confirm the RNA-seq result, we determined lincRNA-p21 expression in the isolated hepatocyte by qRT-PCR, showing that hepatocyte lincRNA-p21 significantly increased after CCl4-injection (Fig. 1B).

Results

Conclusion