Pirfenidone anti-fibrotic effects are partially mediated by the inhibition of MUC1 bioactivation

Abstract

Pirfenidone is a pleiotropic molecule approved to treat idiopathic pulmonary fibrosis (IPF). Pirfenidone has demonstrated to downregulate transforming growth factor-β1 (TGF-β1) cellular effects. However, its anti-fibrotic mechanism remains unclear. Here, we aim to analyze the effects of pirfenidone on the TGF-β1 canonical and non-canonical pathways, as well as, on the most characteristic IPF cellular processes. Results observed in this work showed that TGF-β1-induced canonical SMAD3 and noncanonical ERK1/2 phosphorylations were not inhibited by pirfenidone in alveolar A549 and lung fibroblasts MRC5 cells. In contrast, pirfenidone inhibited TGF-β1-induced MUC1-CT Thr 41 (1224) and Tyr 46 (1229) phosphorylations, thus reducing the β-catenin activation. Additionally, immunoprecipitation and immunofluorescence studies in ATII cells and lung fibroblasts showed that pirfenidone inhibited the formation and nuclear translocation of the transcriptional fibrotic TGF-β1-induced phospho-SMAD3/MUC1-CT/active-β-catenin complex, and consequently the SMAD-binding element activation (SBE). This study provided also evidence of the inhibitory effect of pirfenidone on the TGF-β1-induced ATII to mesenchymal and fibroblast to myofibroblast transitions, fibroblast proliferation and ATII and fibroblast senescence. Therefore, it indicates that pirfenidone's inhibitory effect on TGF-β1-induced fibrotic cellular processes is mediated by the inhibition of MUC1-CT phosphorylation, β-catenin activation, nuclear complex formation of phospho-SMAD3/MUC1-CT/active β-catenin and SBE activation, which may be of value to further develop anti-fibrotic IPF therapies.

Ferroptosis-Related Genes in Bronchoalveolar Lavage Fluid Serves as Prognostic Biomarkers for Idiopathic Pulmonary Fibrosis

“…It could be that the drug treatment changes the expression of these genes. The anti-fibrotic effects of pirfenidone are proved that partially mediated by the inhibition of MUC1 bioactivation ( 59 ). Second, the sample size of the tissue datasets (28 normal and 84 IPF) is less than the BALF dataset (28 normal and 176 IPF), which could also contribute to the difference in the results.…”

Fibroblast Senescence in Idiopathic Pulmonary Fibrosis

“…Pirfenidone is a pleiotropic molecule approved to be one of the antifibrotic drugs to IPF. It inhibits the MUC1 phosphorylation and β-catenin activation induced by TGF-β1 and prevents SMAD binding elements from forming or activating, thereby combating the fibroblast senescence in IPF (Ballester et al, 2020). Nintedanib inhibits TGF-β1 signal transduction intracellularly and induces IPF fibroblasts to autophagy, thereby down-regulating ECM production (Rangarajan et al, 2016).…”

Membrane particles from mesenchymal stromal cells reduce the expression of fibrotic markers on pulmonary cells

“…We used the A549 cell line to study the effect of MP on cell-released proteins. Although the A549 cell line is from a cancer patient, it has been broadly used to model alveolar type II epithelial cells behavior [ 44 , 45 ]. MP decreased the gene expression of profibrotic proteins such as Col 1A1, Fibronectin and PAI-1 in A549 cells.…”