miRNA-101a inhibits liver fibrosis induced by activated hepatic stellate cell through upregulating IRE1α signaling pathway / 中华肝胆外科杂志

ABSTRACT

Objective:To investigate the role of microRNA (miRNA)-101a in the liver fibrosis induced by activated hepatic stellate cell (HSC), through upregulating IRE1α signaling pathway.Methods:Carbon tetrachloride (CCl 4) induced liver fibrosis model of mice was established. RT-PCR was used to measure the mRNA level of miRNA-101a in liver tissue of mice. Protein level of α smooth muscle actin(αSMA), collagen I and IRE1α were investigated by Western blot. It was divide into Vehicle, TGFβ1, TGFβ1+ miRNA-NC and TGFβ1+ miRNA-M groups. TGFβ1+ miRNA-NC and TGFβ1+ miRNA-M group were transfected with miRNA-101a mimic negative control and miRNA-101a mimic, respectively. After the corresponding treatments, mRNA level of miRNA-101a was detected by RT-PCR, the protein level of αSMA、collagen I and IRE1α were measured by Western blot. Results:Compared to normal mice, the fibrotic deposition in liver tissue of CCl 4 group was increased significantly [(0.17±0.06) vs. (2.09±0.39), P<0.001)]. Protein level of αSMA, collagen I and IRE1α was increased significantly in the model group [(1.00±0.23) vs. (4.09±0.80), (1.00±0.21) vs. (4.98±1.19), (1.00±0.24) vs. (3.27±0.65), all P<0.001)]. While the mRNA level of miRNA-101a was decreased (1.00±0.05) vs. (0.43±0.05), P<0.001). In vitro study, we found that TGFβ1 could inhibit the mRNA expression of miRNA-101a, induced HSC-T6 activation and then up-regulated protein expression of αSMA, collagen I and IRE1α. Compared to TGFβ1+ miRNA-NC group, the expression of miRNA-101a in TGFβ1+ miRNA-M group increased significantly [(0.59±0.19) vs. (1.89±0.20), P<0.001)]. The protein levels of αSMA, collagen I were reduced by over expression of miRNA-101a [(2.65±0.69) vs. (0.84±0.13), (3.15±0.59) vs. (1.31±0.25), all P<0.05)], and the protein content of IRE1α was down-regulated [ (2.63±0.47) vs. (1.03±0.15), P<0.001)]. Conclusion:miRNA-101a may play a critical role in the inhibition of HSC activation and liver fibrogenesis by blocking IRE1α signaling pathway.