Abstract
Excessive extracellular matrix deposition, in particular collagen, is an important cause of lung fibrosis. Heat shock protein 47 (HSP47), a collagen-binding protein, plays an important role in the intracellular processing of procollagen. A small molecule that blocks the collagen chaperone function of HSP47 has been reported as an HSP47 inhibitor. The aim of this study was to assess the effect of the HSP47 inhibitor on collagen synthesis and other fibrotic process in vitro. We evaluated collagen expression by western blot, and determined cell viability and migration by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and scratch test, respectively, in human and mouse lung fibroblasts. Treatment of lung fibroblasts with HSP47 siRNA decreased collagen type I expression. Similarly, the HSP47 inhibitor decreased collagen type I expression in transforming growth factor beta 1 (TGF-β1)-treated lung fibroblasts in a dose-dependent manner. The inhibitor also decreased the viability and cell migration ability of TGF-β1-treated lung fibroblasts. Overall, we demonstrated that HSP47 is a potential therapeutic target for pulmonary fibrosis. The small molecule HSP47 inhibitor may mediate antifibrotic effects by suppressing the overexpression of collagen, and inhibiting the viability and migration of fibroblasts. Further research is needed to clarify the therapeutic potential of this HSP47 inhibitor for pulmonary fibrosis.