Pirfenidone inhibits TGF-β1-induced over-expression of collagen type I and heat shock protein 47 in A549 cells

Abstract

BackgroundPirfenidone is a novel anti-fibrotic and anti-inflammatory agent that inhibits the progression of fibrosis in animal models and in patients with idiopathic pulmonary fibrosis (IPF). We previously showed that pirfenidone inhibits the over-expression of collagen type I and of heat shock protein (HSP) 47, a collagen-specific molecular chaperone, in human lung fibroblasts stimulated with transforming growth factor (TGF)-β1 in vitro. The increased numbers of HSP47-positive type II pneumocytes as well as fibroblasts were also diminished by pirfenidone in an animal model of pulmonary fibrosis induced by bleomycin. The present study evaluates the effects of pirfenidone on collagen type I and HSP47 expression in the human alveolar epithelial cell line, A549 cells in vitro.MethodsThe expression of collagen type I, HSP47 and E-cadherin mRNAs in A549 cells stimulated with TGF-β1 was evaluated by Northern blotting or real-time PCR. The expression of collagen type I, HSP47 and fibronectin proteins was assessed by immunocytochemical staining.ResultsTGF-β1 stimulated collagen type I and HSP47 mRNA and protein expression in A549 cells, and pirfenidone significantly inhibited this process. Pirfenidone also inhibited over-expression of the fibroblast phenotypic marker fibronectin in A549 cells induced by TGF-β1.ConclusionWe concluded that the anti-fibrotic effects of pirfenidone might be mediated not only through the direct inhibition of collagen type I expression but also through the inhibition of HSP47 expression in alveolar epithelial cells, which results in reduced collagen synthesis in lung fibrosis. Furthermore, pirfenidone might partially inhibit the epithelial-mesenchymal transition.

FK506-Binding Protein 10, a Potential Novel Drug Target for Idiopathic Pulmonary Fibrosis

“…In contrast, we did not observe any effect of pirfenidone in this context. Previous studies in human lung fibroblasts and A549 cells have shown moderate reduction of collagen I expression only at concentrations higher than those used in this study (1.0 mM vs. 1.6 and 2.7 mM pirfenidone, respectively [35,36]). The effect of pirfenidone on TGF-b-induced collagen secretion in vitro has, to our knowledge, only been studied in trabecular meshwork Statistical analysis was performed using paired two-tailed t test for comparison of FKBP10 siRNA vs. scrambled siRNA control.…”

Serum heat shock protein 47 levels are elevated in acute exacerbation of idiopathic pulmonary fibrosis

“…Oishi et al reported that proinflammatory, profibrotic, and proangiogenic cytokines, including TGF-β were eluted from PMX fibers used for the treatment of AE-IPF and suggested that adsorption of such cytokines onto PMX fibers might be one of the mechanisms of action involved. Because TGF-β has been reported to induce the expression of HSP47 (Hisatomi et al 2012;Nakayama et al 2008), adsorption of cytokines by PMX-DHP could decrease expression of HSP47 and thereby attenuate the progression of inflammation and fibrosis in the DAD lung. The precise effects of PMX-DHP on HSP47 expression should be investigated in a future study.…”

A Novel Genomic Signature with Translational Significance for Human Idiopathic Pulmonary Fibrosis

“…We therefore assessed the effect of pirfenidone, which is an orally active synthetic molecule that has been recently approved for the treatment of IPF in some countries, but not in the United States (36), in the bleomycininduced lung fibrosis model using a "therapeutic" treatment regimen. Antiinflammatory and antifibrotic activities of pirfenidone had been previously demonstrated in vivo (37) and in vitro (38)(39)(40)(41). Effects of pirfenidone on the newly identified translational gene subset were monitored by QPCR at Day 14.…”