Mitochondrial oxidative stress index, activity of redox-sensitive aconitase and effects of endogenous anti- and pro-oxidants on its activity in control, Alzheimer's disease and Swedish Familial Alzheimer's disease brain

Efficient function of the mitochondrial respiratory chain and the citric acid cycle (CAC) enzymes is required for the maintenance of human brain function. A conception of oxidative stress (OxS) was recently advanced as a disruption of redox signalling and control. Mitochondrial OxS (MOxS) is implicated in the development of Alzheimer's disease (AD). Thus, both pro-and anti-oxidants of the human body and MOxS target primarily the redox-regulated CAC enzymes, like mitochondrial aconitase (MAc). We investigated the specific activity of the MAc and MOxS index (MOSI) in an age-matched control (Co), AD and Swedish Familial AD (SFAD) postmortem autopsies collected from frontal cortex (FC) and occipital primary cortex (OC) regions of the brain. We also examined whether the mitochondrial neuroprotective signalling molecules glutathione, melatonin and 17-beta-estradiol (17 beta E) and mitochondrially active pro-oxidant neurotoxic amyloid-beta peptide can modulate the activity of the MAc isolated from FC and OC regions similarly or differently in the case of Co, AD and SFAD. The activity of redox-sensitive MAc may directly depend on the mitochondrial oxidant/antioxidant balance in age-matched Co, AD and SFAD brain regions.