Effect of MicroRNA-9 on cell proliferation and collagen synthesis in hepatic stellate cells by downregulation of TGFBR2

Abstract

Objective To investigate the effect of MicroRNA-9 (miR-9) on cell proliferation and collagen synthesis in hepatic stellate cells (HSCs), and to explore the potential mechanism. Methods HSC-T6 cells were cultured and transfected with miR-9 mimics with lipofectamine 2000. After incubation 48 h, the cells were collected and total proteins and RNAs were extracted. The expression of miR-9 was detected by quantitative real time polymerase chain reaction (qRT-PCR). The protein expression of type I collagen and type III collagen were measured by Western blot. The methyl thiazolyl tetrazolium (MTT) method was used to asses the proliferation of HSC-T6 cells. The expression of transforming growth factor-β1 receptor 2 (TGFBR2) was detected by qRT-PCR and Western blot. Results Compared to the control group, miR-9 expression in HSCs was increased in the miR-9 mimics group (P<0.05), type Ⅰ and type Ⅲ collagen protein expression was reduced by (44±2)% and (50±3)%(P<0.01), respectively. The proliferation activity of HSCs was decreased by (48±4)% (P<0.05). The expression of TGFBR2 was inhibited in the miR-9 mimics group. Conclusions Upregulation of miR-9 plays a role on suppressing cell proliferation and collagen synthesis in HSCs. This process might be mediated by downregulation of TGFBR2. Key words: MicroRNAs/PD/ME; Hepatocytes/CY/DE; Astrocytes/DE; Cell proliferation/DE; Collagen/ME