Differential Quantitative Proteomics of Human Microvascular Endothelial Cells 1 by iTRAQ Reveals Palladin to be a New Biomarker During TGF-?1 Induced Endothelial Mesenchymal Transition

Abstract

The study uses global quantitative proteomics to investigate the molecular mechanisms behind the induction of endothelial-mesenchymal transition (EndMT) by transforming growth factor-β (TGF-β). Orbitrap Velos mass spectrometers and iTRAQ -a labeling-based analysis were used to perform a global and quantitative comparison of two proteomes of Human Microvascular Endothelial Cells-1 (HMEC-1) treated or not treated by TGF-β1. iTRAQ analysis identified 43 differentially-expressed proteins in the early stages of EndMT induced by TGF-β1. From 5522 identified proteins, 26 were downregulated and 17 were upregulated, including proteins such as palladin, POTE I, torsin A and nucleoporin (NDC1). Further analysis of palladin revealed its increased mRNA and protein expression in response to TGF-β and Snail transcription factor. Our findings demonstrate that the newly-identified proteins may be involved in early stages of biological processes leading to EndMT.