IMPAIRMENT IN MITOCHONDRIAL CYTOCHROME-OXIDASE GENE-EXPRESSION IN ALZHEIMER-DISEASE

Brains from 5 patients with Alzheimer's disease (AD) showed a 50%-65% decrease in mRNA levels of the mitochondrial-encoded cytochrome oxidas e (COX, a marker of oxidative metabolism) subunits I and III in the mi ddle temporal association neocortex, but not in the primary motor cort ex, as compared to 5 control brains. The amount of mitochondrial-encod ed 12S rRNA was not altered, nor was the amount of nuclear-encoded lac tate dehydrogenase B mRNA (a marker of glycolytic metabolism). These d ata suggest that the decrease in COX I and III subunits mRNA in affect ed brain regions may contribute to reduced brain oxidative metabolism in AD.