The neuroprotective effect of heme oxygenase (HO) on oxidative stress in HO-1 siRNA-transfected HT22 cells

To investigate the role of heme oxygenase (HO) isozymes, we used siRNA technology to suppress HO-1 expression. HO-1 siRNA-transfected HT22 cells were vulnerable to hydrogen peroxide- and 4-hydroxynonenal-induced cytotoxicity. Biliverdin and bilirubin, degradative products of heme catalyzed by HO, protected HT22 cells from the insult of these oxidative stressors. These results suggest that inducible HO-1 plays a protective role against oxidative stress in HT22 cells.