MiR-200b ameliorates myofibroblast transdifferentiation in precancerous oral submucous fibrosis through targeting ZEB2.

Yi‐Wen Liao,Cheng‐Chia Yu,Yu‐Chao Chang,Pei‐Ling Hsieh

doi:10.1111/jcmm.13690

Abstract

Oral submucous fibrosis (OSF) is a progressive scarring disease. MicroRNA‐200b (miR‐200b) has been reported as a tumour suppressor, but its role in the precancerous OSF remains unknown. In this study, we investigated the impact of miR‐200b on myofibroblastic differentiation activity. Arecoline is a major areca nut alkaloid and has been employed to induce the elevated myofibroblast activity in human buccal mucosal fibroblasts (BMFs). Treatment of arecoline in BMFs dose‐dependently reduced gene expression of miR‐200b, which corresponded with the decreased expression of miR‐200b in fBMFs. The arecoline‐induced myofibroblast activities were abolished by overexpression of miR‐200b in BMFs, and the same results were observed in fBMFs. In addition, α‐SMA was inhibited by an increase in miR‐200b. We further demonstrated that miR‐200b‐mediated decrease in ZEB2 led to down‐regulation of α‐SMA, vimentin. Loss of miR‐200b resulted in enhanced collagen contraction and migration capabilities, and knockdown of ZEB2 reversed these phenomena. Lastly, we showed the expression of miR‐200b was significantly less and ZEB2 was markedly higher in OSF tissues. These results suggested that down‐regulation of miR‐200b may contribute to the pathogenesis of areca quid‐associated OSF through the regulation of ZEB2 and myofibroblast hallmarks.

Highlights

Oral submucous fibrosis (OSF) is a chronic progressive scarring disease and has been recognized as one of the oral potentially malignant disorders
Our results showed that overexpression of miR-200b can prevent the elevated myofibroblast activity in buccal mucosal fibroblasts (BMFs) after arecoline stimulation and we observed the similar effect in fibroblasts from OSF tissues (fBMFs) with reduced expression of myofibroblast marker, a-smooth muscle actin (SMA), indicating that miR-200b may possess the capacity to reverse myofibroblast transdifferentiation
We proved that miR-200b repressed Slug, vimentin and a-SMA via directly binding to ZEB2, leading to diminished myofibroblast activity

Summary

| INTRODUCTION

Oral submucous fibrosis (OSF) is a chronic progressive scarring disease and has been recognized as one of the oral potentially malignant disorders. Our previous findings have shown that arecolineinduced myofibroblast transdifferentiation is mediated by ZEB1,13 and inhibition of EMT transcription factor suppressed the pathogenesis of areca quid-induced OSF through down-regulation of myofibroblast activity.[14]. Approaches to decrease the EMT regulating factors may be a promising strategy to inhibit the activation of myofibroblasts after arecoline stimulation, preventing OSF pathogenesis. The EMT-inducing transcriptional factors ZEB1 has been found to be a target of miRNA-192 and inhibition of miR-192 resulted in decreased collagen expression as well as reduced renal fibrosis.[21]. We tested the expression of miR-200b in fibrotic cells and tissues, and investigated its contribution in arecoline-induced and fibrotic myofibroblast activity, including higher collagen gel contractility and migration ability. Our data revealed the anti-fibrotic potential of miR-200b in preventing the progression of OSF

| MATERIALS AND METHODS

| RESULTS

Findings

| DISCUSSION