Serúlópasmín og járn. Tengsl við Alzheimersjúkdóm og Parkinsonsjúkdóm

Abstract

Ceruloplasmin, a multi-copper oxidase with four active copper atoms, oxidizes Fe2+ to Fe3+ and concomittantly fully reduces oxygen to water. The oxygenation of iron is a requisite for transferrin transport of iron and keeping noxious Fe2+ low. In the central nervous system (CNS) Cp is mostly localized in end feet of astrocytes surrounding capillaries and attached by a glycosylphosphatidylinositol-anchor. In aceruloplasminaemia, a rare recessive hereditary disease, complete loss of Cp is accompanied by disorders of iron metabolism and lesions in CNS and outside. In PD Cp concentration and oxidative activity in serum are significantly lowered with iron deposits and lesions in substantia nigra and basal ganglia. Changes in Cp-genes might be causative in these disorders. By inducing neuromelanin synthesis Cp may protect neurons in substantia nigra. In AD Cp activity in serum, but not concentration, is significantly lowered. Changes in Cp-genes have not been verified in AD. Total amounts of iron are not increased in AD brains although iron deposits and cortical lesions are numerous. Total copper is significantly lowered in AD brains. This may result in defective synthesis of Cp and other copper enzymes. - In conclusion, the defective Cp activity, associated with iron disorders, is seemingly of importance in PD and also in AD with other copper enzyme defects possibly involved.