Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial fibrotic lung disease with an undefined etiology and no effective treatments. By binding to cell surface receptors, transforming growth factor-β (TGF-β) plays a pivotal role in lung fibrosis. Therefore, the screening of microRNAs (miRNAs), especially those interrupting the effects of TGF-β, may provide information not only on the pathomechanism, but also on the treatment of this disease. In the present study, we found that miR-153 expression was dysregulated in the lungs of mice with experimental pulmonary fibrosis and TGF-β1 decreased miR-153 expression in pulmonary fibroblasts. Moreover, increased miR-153 levels attenuated, whereas the knock down of miR-153 promoted the pro-fibrogenic activity of TGF-β1, and miR-153 reduced the contractile and migratory activities of fibroblasts. In addition, TGFBR2, a transmembrane serine/threonine kinase receptor for TGF-β, was identified as a direct target of miR-153. Furthermore, by post-transcriptional regulation of the expression of TGFBR2, phosphorylation of SMAD2/3 was also influenced by miR-153. These data suggest that miR-153 disturbs TGF-β1 signal transduction and its effects on fibroblast activation, acting as an anti-fibrotic element in the development of pulmonary fibrosis.