Abstract
Purpose: :
The pathogenicity of the epithelial-mesenchymal transition (EMT) in ocular fibrotic diseases is becoming increasingly recognized. Genes of snail family encode the zinc finger transcription factors previous reported play a critical role in EMT during embryonic development and cancer metastasis. In this work, we aimed to investigate the role of Snail gene in EMT of human retinal pigmental epithelium (RPE) in proliferative vitreoretinopathy (PVR).
Methods: :
PVR model in vitro was induced by RPE cells through exposure to 10ng/ml TGF-β1.RNA was isolated for Real time-PCR to measure snail gene, E-cadherin, ZO-1, fibronectin and α-SMA transcripts using SYBGreen assay. Western blot was used for detection of snail, E-cadherin, zo-1, fibronectin and α-SMA proteins expression. Immunocytochemistry technique was performed to indicate phenotypic changes of RPE cells.
Results: :
Expression of snail mRNA and protein were upregulated in human RPE cells treated with 10 ng/ml TGF-β1. TGF-β1 treatment for 48 h induced snail protein translocation to the nucleus. By contrast, in untreated cells, Snail gene was mainly detectable in the cytoplasm of RPE cells. The cobble-stone-like appearance of RPE was transformed to a mesenchymal morphology after stimulated with TGF-β1 for 24h.These morphological changes were associated with the decreasing expression of epithelial characteristics such as E-cadherin and ZO-1 and the increasing expression of mesenchymal characteristics, including an increase in matrix protein fibronectin and α-SMA.
Conclusions: :
TGF-β1 mediated expression of snail gene in the RPE cells resulted in epithelial mesenchymal transition, suggesting that snail gene may play an important role in pathogenesis of PVR. Future studies will focus on the signal gene transduction pathways involving in this process.
Keywords: proliferative vitreoretinopathy • pathobiology • retinal pigment epithelium