Proteomics study of HOCl - induced oxidative stress response in human HepG2 cell line

Abstract

Hypochlorous acid (HOCl)-mediated oxidative damage to tissue proteins has been implicated in the pathogenesis of various inflammatory diseases such as liver cirrhosis. HOCl has been shown to participate in the cellular oxidation and chlorination of proteins, and is known to deplete intracellular ATP, reduce glutathione (GSH) and cause necrotic/apoptotic cell death. We employed a 2-dimensional difference gel electrophoresis (2D-DIGE) approach, coupled with western blotting and mass spectrometry to identify protein targets in liver cells that are affected by this oxidant. In our study, we identified various mitochondria and nuclear proteins involved in antioxidant activities, metabolism and cell proliferation that were differentially expressed and/or carbonylated upon HOCl treatment. Our results additionally show the possible chlorination of 2 nuclear proteins, hnRNPK and lamin A/C. These results shed new light towards our understanding the underlying basis of chlorination, oxidation and molecular players of HOCl-mediated oxidative stress in cells.