Heme oxygenase-1 and carbon monoxide suppress autoimmune neuroinflammation.

Heme oxygenase-1 (HO-1, encoded by HMOX1) dampens inflammatory reactions via the catabolism of heme into CO, Fe, and biliverdin. We report that expression of HO-1 dictates the pathologic outcome of experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis (MS). Induction of EAE in Hmox1(-/- )C57BL/6 mice led to enhanced CNS demyelination, paralysis, and mortality, as compared with Hmox1(+/+) mice.