Journal Article

Activation of Wnt/β‐catenin signalling is required for TGF‐β/Smad2/3 signalling during myofibroblast proliferation

Zhao, Ping, Xu, Liang, Zhou, Wen‐Cheng, Li, De‐Lin, Mo, Xiao‐Ting, Zhang, Zhihui, Cui, Wen‐Hui, Li, Liu‐Cheng, Gao, Jian

2017

Overview

Fibrosis in animal models and human diseases is associated with aberrant activation of the Wnt/β‐catenin pathway. Despite extensive research efforts, effective therapies are still not available. Myofibroblasts are major effectors, responsible for extracellular matrix deposition. Inhibiting the proliferation of the myofibroblast is crucial for treatment of fibrosis. Proliferation of myofibroblasts can have many triggering effects that result in fibrosis. In recent years, the Wnt pathway has been studied as an underlying factor as a primary contributor to fibrotic diseases. These efforts notwithstanding, the specific mechanisms by which Wnt‐mediated promotes fibrosis reaction remain obscure. The central role of the transforming growth factor‐β (TGF‐β) and myofibroblast activity in the pathogenesis of fibrosis has become generally accepted. The details of interaction between these two processes are not obvious. The present investigation was conducted to evaluate the level of sustained expression of fibrosis iconic proteins (vimentin, α‐SMA and collagen I) and the TGF‐β signalling pathway that include smad2/3 and its phosphorylated form p‐smad2/3. Detailed analysis of the possible molecular mechanisms mediated by β‐catenin revealed epithelial–mesenchymal transition and additionally demonstrated transitions of fibroblasts to myofibroblast cell forms, along with increased activity of β‐catenin in regulation of the signalling network, which acts to counteract autocrine TGF‐β/smad2/3 signalling. A major outcome of this study is improved insight into the mechanisms by which epithelial and mesenchymal cells activated by TGFβ1‐smad2/3 signalling through Wnt/β‐catenin contribute to lung fibrosis.

• Publisher: John Wiley & Sons, Inc,John Wiley and Sons Inc
• Subject: A549 Cells / Actins - genetics / Actins - metabolism / Animal models / Animals / Autocrine signalling / beta Catenin - genetics / beta Catenin - metabolism / Cadherins - genetics / Cadherins - metabolism / Cell Line / Cell Proliferation / Collagen (type I) / Collagen Type I - genetics / Collagen Type I - metabolism / Epithelial-Mesenchymal Transition / Extracellular matrix / Fibroblasts / Fibroblasts - metabolism / Fibroblasts - pathology / Fibrosis / Gene Expression Regulation / Humans / Mesenchyme / Molecular modelling / myofibroblast proliferation / Myofibroblasts - metabolism / Myofibroblasts - pathology / Original / Pulmonary fibrosis / Rats / Rats, Sprague-Dawley / Signal Transduction / Smad2 protein / Smad2 Protein - genetics / Smad2 Protein - metabolism / Smad2/3 / Smad3 Protein - genetics / Smad3 Protein - metabolism / Transforming Growth Factor beta1 - genetics / Transforming Growth Factor beta1 - metabolism / Transforming growth factor-b / Transforming growth factor-b1 / Vimentin / Vimentin - genetics / Vimentin - metabolism / Wnt protein / Wnt Proteins - genetics / Wnt Proteins - metabolism / Wnt/β‐catenin / β-Catenin