Effects of 4-hydroxy-2-nonenal on cultured human aortic endothelial cells and myocardial cell

Abstract

To study the effects of 4-hydroxy-2-nonenal (HNE) on cultured human aortic endothelial cells and myocardial cells so as to explore the mechanism of the pathogenesis of atherosclerosis. In situ cell death technique, quantitative DNA damage detection and immunohistochemistry were used to identify the cell apoptosis and DNA damage in cultured human aortic endothelial cells and myocardial cells. Tail moment was 32.80+/-1.12, 44.30+/-0.99 and 74.6+/-0.97 when HAOEC were treated with 5 muM, 10muM and 15 muM of HNE for 10 hours, which were of statistical significance when compared with the normal group (6.0+/-0.67, P < 0.001 respectively), But when HAOEC was treated with 1 muM of HNE, the tail moment was 11.3+/-0.9, which was of no statistical difference compared with the untreated group(P>0.05). When human aortic endothelial cells (HAOEC) were treated with 5 muM, 10muM and 15 muM of HNE for 10 hours, the percent of nonviable cells were 5.70+/-0.55, 25.96+/-2.02 and 50.80+/-3.40 (P<0.001 respectively when compared with the normal group with the percent of 0.27+/-0.13). But when HAOEC was treated with 1 muM of HNE for 10 hours, the percent of nonviable cells was 2.5+/-0.22, and no difference was observed when compared with the untreated group (P>0.05). When cultured human myocardial cells were treated with 5 muM of HNE for 10 hours, TUNEL staining showed a greater number of apoptotic cells in HNE-treated human myocardial cells. No TUNEL-positive cells were observed in untreated group. When HAOEC was treated with 5 muM of HNE for 10 hours, immunocytochemical labeling with polyclonal antibody to HNE-modified proteins revealed specific cytoplasmic staining in cells incubated with HNE, whereas staining was absent in control cells incubated with vehicle. But 1 muM of HNE treatment didn't present positive stainings. Higher concentrations of HNE (10 muM and 15 muM) showed much stronger positive stainings. HNE induces DNA damage and cell apoptosis of cultured aortic endothelial cells and myocardial cells. The DNA damage and apoptosis levels are proportional to the HNE concentrations.