Platelet cytochrome oxidase and citrate synthase activities in APOE ?4 carrier and non-carrier Alzheimer's disease patients.

ABSTRACT: A degradation product of APOE ?4-encoded apolipoprotein E protein targets mitochondria and inhibits cytochrome oxidase (COX), and autopsy brains from young adult APOE ?4 carriers show reduced COX activity. To further explore relationships between APOE alleles and COX, we measured platelet mitochondria COX activity in AD subjects with (n=8) and without (n=7) an APOE ?4 allele and found the mean COX activity, when normalized to sample total protein, was lower in the APOE ?4 carriers (p<0.05). Normalizing COX activity to citrate synthase (CS) activity eliminated this difference, but notably the mean CS activity was itself lower in the APOE ?4 carriers (p<0.05). COX and CS protein levels did not appear to cause the lower APOE ?4 carrier COX and CS Vmax activities. If confirmed in larger studies, these data could suggest mitochondria at least partly mediate the well-recognized association between APOE alleles and AD risk.

SUBMITTER: Wilkins HM 

PROVIDER: S-EPMC5406545 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature