The proliferation, directional migration to the vitreous and 
epithelial-mesenchymal transition (EMT) of quiescent, differentiated retinal 
pigment epithelium (RPE) cells is a major feature in the development of 
proliferative vitreoretinopathy (PVR) following exposure of the 
immuno-privileged eye niche to serum components, thrombin among them. We have 
previously documented thrombin induction of RPE cell proliferation and 
migration. We here analyzed the effect of thrombin on the E/N cadherin switch, a 
hallmark of EMT. Results show that thrombin induces the specific repression of 
epithelial E-cadherin gene transcription, alongside with the up-regulation of 
mesenchymal N-cadherin protein in RPE cells. We demonstrate, for the first time, 
that thrombin induces E-cadherin repression by stimulating snail-2 (SLUG) 
transcription factor expression, and the concomitant up-regulation of N-cadherin 
through the transcription-independent increase in protein translation promoted 
by PI3K/PKC-ζ/mTOR signaling. Our present findings suggest that the activation 
of protease-activated receptor-1 (PAR-1) by thrombin induces EMT of RPE cells, 
further supporting a central role for thrombin in PVR pathogenesis.