In porcine aortic endothelial cells, a 20-h incubation with hydrogen peroxide (0.5 mM) markedly reduced the number of viable cells. A 6-h preincubation with linsidomine (SIN-1, 0.5 mM) protected endothelial cells from hydrogen peroxide-dependent cytotoxicity and increased the surviving endothelial cell fraction by 85%. This protection was associated with a 2.5- fold induction of ferritin heavy chain mRNA and ferritin protein by SIN-1. The nitric oxide donor glyceryl trinitrate was also found to induce transcriptional and translational expression of ferritin heavy chain. A protective effect comparable to SIN-1 was observed when preincubating the cells with iron-free apoferritin (1 mg/ml). These findings suggest that ferritin induction, presumably via release of nitric oxide, may be a mechanism underlying long-term cytoprotection by SIN-1 against oxidative stress.
Bibliographical noteFunding Information:
This work was supported by the Deutsche Forschungsge-meinschaft (Schr 298/8-1). We thank Petra Schwartz for expert technical assistance and Dr. Gaetano Cairo for generously providing ferritin heavy-chain cDNA used as hybridization probe.