Induction of heme oxygenase-1 in the brains of scrapie-infected mice

Heme oxygenase-1 (HO-1) is an inducible enzyme that catalyzes the rate-limi ting step in the degradation of heme to biliverdin, carbon monoxide and iro n, and its expression can be used as a marker for oxidative stress. Oxidati ve stress has been reported to be associated with neurodegenerative disease s including Alzheimer's disease. It is possible that oxidative stress is al so involved in the disease process seen in scrapie, the archetype transmiss ible spongiform encephalopathy. In this study, we report that HO-1 is signi ficantly increased in the scrapie-infected group compared to an age-matched control group. Immunohistochemistry showed a pronounced increase of immuno staining of th is protein in the infected group compared to the minimal amo unt of staining in the control group. These results support that oxidative stress is closely associated with the pathogenesis of scrapie and that it m ight contribute to neurodegeneration in this disease. (C) 2000 Elsevier Sci ence Ireland Ltd. All rights reserved.