Antifibrotic Effect Of MiR-29b In MRC-5 Cells Co-cultured With A549 Cells

Objective:Idiopathic pulmonary fibrosis(IPF) is a progressive lung disorder of unknown etiology, and no effective treatment. IPF is characterized by the progressive excessive accumulation of fibroblasts and myofibroblasts, and extracellular matrix in the lung.Micro RNAs(mi RNAs) are small regulatory RNAs that may play an important roles in a wide range of pathophysiological processes. Recently, there are evidences much more suggests mi RNA contribute to pathogenesis of IPF. In this study we investigate the effects of mi R-29 b on the Col I synthesis in the co-cultured system including MRC-5cells and A549 cells, and discuss the prophylacic effect of mi R-29 b on pulmonary fibrosis.Methods:The MRC-5 cells co-culture with A549 cells by Transwell chambers. Mi R-29 b was transfected into MRC-5 cells through Lipofectamine, and TGF-β1 to stimulate the corresponding cell group, they were divided into five groups of blank control group,TGF-β1 group, mi R-29 b negative transfection+TGF-β1 group, mi R-29 b transfection+TGF-β1 group, mi R-29 b tranfection group. q RT-PCR was used to detect the expression levels of Col I(collegen I) and mi R-29 b in which groups, and the expression level of Col I protein was measured by Western blotting.Results:(1) Compared with the blank control group, mi R-29 b in the transfection group expression level was increased 127 times(P < 0.01)detected by PCR. Overexpression of mi R-29 b in MRC-5 cell transfection group succeeded through Lipofectamin2000.(2) PCR showed that the expression level of Col I in the mi R-29 b transfection+TGF-β1 group was decreased compared with TGF-β1 group and mi R-29 b negative transfection +TGF-β1 group(P < 0.05).(3) The Col I protein expression was detected by Western blotting, the Col I expressed of mi R-29 b transfection + TGF-β1 group lower than the the TGF-β1group and mi R-29 b negative transfection +TGF-β1 group expressed(P < 0.05)Conclusion:Overexpression of mi R-29 b in MRC-5 cell can reduce the Col I expressed of MRC-5 cells co-cultured with A549 after TGF-β1 stimulation, and reduced the synthesisof extracellular matrix. mi R-29 b might be a potential therapeutic event for pulmonary fibrosis.