Gradual Alteration of Mitochondrial Structure and Function by β-Amyloids: Importance of Membrane Viscosity Changes, Energy Deprivation, Reactive Oxygen Species Production, and Cytochrome c Release
- Cite this article as:
- Aleardi, A.M., Benard, G., Augereau, O. et al. J Bioenerg Biomembr (2005) 37: 207. doi:10.1007/s10863-005-6631-3
Intracellular amyloid beta-peptide (Aβ) accumulation is considered to be a key pathogenic factor in sporadic Alzheimer’s disease (AD), but the mechanisms by which it triggers neuronal dysfunction remain unclear. We hypothesized that gradual mitochondrial dysfunction could play a central role in both initiation and progression of sporadic AD. Thus, we analyzed changes in mitochondrial structure and function following direct exposure to increasing concentrations of Aβ1−42 and Aβ25−35 in order to look more closely at the relationships between mitochondrial membrane viscosity, ATP synthesis, ROS production, and cytochrome c release. Our results show the accumulation of monomeric Aβ within rat brain and muscle mitochondria. Subsequently, we observed four different and additive modes of action of Aβ, which were concentration dependent: (i) an increase in mitochondrial membrane viscosity with a concomitant decrease in ATP/O, (ii) respiratory chain complexes inhibition, (iii) a potentialization of ROS production, and (iv) cytochrome c release.