Tgf-β Regulates Proliferation and Emt-Related Gene Expression of Human Corneal Epithelial Cell

Abstract

Purpose: : Epithelial-mesenchymal transition (EMT) is estimated to play an important role in re-epithelialization during ocular wound healing. However, it remains unclear the underlying mechanism of EMT-induction in human corneal epithelial cells (HCECs). We investigated the effect of TGF-β on cellular response and EMT-related gene expression in HCECs.

Methods: : TGF-β mediated cellular proliferation, apoptosis and activation of TGF-β signaling pathway of HCECs were evaluated by MTT assay, flowcytometry and immunoblotting, respsectively. Quantitative real-time RT-PCR (qRT-PCR) was performed to measure the mRNA levels of several EMT markers such as CDH1, CDH2, VIM, FN1, SNAI1, SNAI2 and TWIST1.

Results: : TGF-β-stimulation inhibited the cellular proliferation, and induced cell cycle arrest and apoptosis, significantly. Immunoblotting analysis demonstrated TGF-β increased the expression of phospho-smad2 in time and dose dependent manners. The mRNA expression levels of VIM, FN1, SNAI1, SNAI2 were significantly induced by TGF-β (p<0.05), whereas TWIST1 expression was unchanged in detecting qRT-OCR. These effects were canceled by a TGF-βR inhibitor SB431542. In addition, we detected a cross-talk between signaling pathway of TGF-β and EGFR in HCECs.

Conclusions: : TGF-β regulates the cell proliferation and expression levels of EMT makers in HCECs. This study may provide a novel insight into TGF-β₁-mediated EMT.

Keywords: EMT (epithelial mesenchymal transition) • cornea: epithelium • gene/expression