Glutathione consumption and glutathione peroxidase inactivation in fibroblast cell lines by 4-hydroxy-2-nonenal

Treatment of cultured fibroblasts, designated HA I cells, with 4-hydroxy-2-nonenal (4HNE) in doses up to 50 nmol/106 cells for 3 h results in dose-dependent cytotoxicity measured by clonogenic cell survival with 50% cytotoxicity achieved at 32 nmol 4HNE/106 cells. 4HNE treatment also resulted in dose-dependent reduction of cellular glutathione (GSH) content and loss of glutathione peroxidase (GPx) activity at 4HNE doses greater than 15 nmol/106 cells. By comparison, a 95% oxygen-resistant variant of HAI cells, designated 02R95 cells, and a hydrogen peroxide-resistant variant of HA 1 cells, designated OC14 cells, were found resistant to 4HNE cytotoxicity requiring 54 nmol 4HNE/106 cells and 75 nmol 4HNE/106 cells, respectively, for 50% cytotoxicity. In 02R95 cells, dosedependent decreases were seen in GSH levels and GPx activity. In OC14 cells, however, any reduction in cellular GSH levels required doses of 4HNE greater than 30 nmol/106 cells, and GPx activity remained unchanged. No changes were seen in glutathione-S-transferase activity in any of the cell lines at any dose tested. These data indicate a correlation between glutathione modification, in a manner that prevents its recycling, the ability to inactivate enzymes with active site selenocysteine residues and the cytotoxicity of a,ß-unsaturated aldehydes such as 4HNE.