4-Hydroxynonenal induces an increase in expression of Receptor for Activating C Kinase 1 (RACK1) in Chinese hamster V79-4 lung cells

Abstract

4-Hydroxy-trans-2-nonenal (HNE) is a cytotoxic α,β-unsaturated aldehyde implicated in the pathology of several diseases that have an oxidative stress mechanism, including atherosclerosis, diabetes, alcohol-induced liver disease, and neurodegenerative disorders. As the most toxic aldehydic product of lipid peroxidation, HNE is known to exert a range of biological effects in a concentration-dependent manner. In this study, the effect of HNE on the levels of proteins in V79-4 Chinese hamster lung cells was investigated using two-dimensional electrophoresis and mass spectrometry. The results revealed that the expression of 23 proteins was increased by at least 2-fold and the expression of 19 proteins was decreased by at least 2-fold after exposure to 10 μM HNE for 24 h. Decreased proteins included the metabolic enzyme phosphoglycerate kinase 1 (PGK1), levels of which were decreased by 47%. Levels of the apoptotic indicator Lamin C were decreased by 33%. In contrast, levels of the scaffolding protein Receptor for Activating C Kinase 1 (RACK1) were increased by 2-fold after treatment with 10 μM HNE for 24h, and this was confirmed using quantitative PCR of reverse-transcribed mRNA and Western blots. The role of RACK1 in mediating the induction of apoptosis in response to 10 μM HNE was confirmed using RACK1-specific siRNA. The results from this study provide new information on the mechanism of adaptive stress response to HNE and also identify potential new biomarkers of exposure to HNE.

Keywords: 2D electrophoresis; 4-Hydroxynonenal; Lamin C; Mass spectrometry; PGK1; RACK1.