Abstract
Purpose:
To investigate the role of microRNAs (miRNAs) in TGF-β1 induced retinal pigment epithelial-mesenchymal transition (EMT) during proliferative vitreoretinopathy (PVR).
Methods:
Microarray assay was performed for the identification of differentially expressed miRNAs in human retinal pigment epithelium (RPE) cell line ARPE-19 under normal and TGF-β1. The results were verified by quantitative real time RT-PCR (qRT-PCR). The function of miRNAs in TGF-β1-induced retinal pigment epithelial-mesenchymal transition was assessed by the transfection of specific miRNA inhibitors and mimics. Luciferase reporter gene assays and western blot analysis were performed to validate the target genes of miRNA.
Results:
Microarry analysis identified six specific miRNAs which expressed differently in normal ARPE-19 cells as compared to TGF-β1 treated ARPE-19 cells. Among them, miR-135b, miR-550a and miR-29b were downregulated and miR-455-3p, miR-22* and miR-3138 were upregulated. qRT-PCR was carried out to warrant the accuracy of the microarray assay. The results showed that miR-3138 was downregulated. We further investigate the role of miR-135b in TGF-β 1induced RPE cells EMT. Enforced expression of the miR-135b was sufficient to prevent TGF-β1-induced EMT. Conversely, Inhibition of the miR-135b was sufficient to induce EMT.
Conclusions:
These data suggest that downregulation of the miR-135b may be an important step inTGF-β1 induced retinal pigment epithelium EMT during PVR.
Keywords: 512 EMT (epithelial mesenchymal transition) •
701 retinal pigment epithelium •
655 proliferative vitreoretinopathy