The Mitochondrial Permeability Transition Pore and Loss of Mitochondrial Membrane Potential in Aging

This open access review paper discusses what is known of the role of the mitochondrial permeability transition pore in the age-related decrease of mitochondrial membrane potential. This measure is a lens through which one can view the growing dysfunction of mitochondria with advancing age. Every cell contains hundreds of mitochondria, producing chemical energy store molecules, ATP, to power cellular processes. Reduced rates of ATP production lead to cell and tissue dysfunction. This is thought to be an important contribution to degenerative aging, though exactly how it arises from causative mechanisms, such as mitochondrial DNA damage and whatever leads to reduced expression of nuclear proteins necessary to mitochondrial function, remains to be fully determined. It is widely reported that the mitochondrial membrane potential, ∆Ψm, is reduced in aging animals. It was recently suggested that the lower ∆Ψm in aged animals modulates mitochondrial bioenergetics and that this effect is a major cause of aging since artificially increased ∆Ψm in C. elegans increased lifespan. Here, I critically review studies that reported reduction in ∆Ψm in aged animals, including worms, and conclude that many of these observations are best interpreted as evidence that the fraction of depolarized mitochondria is increased in aged cells because of the enhanced activation of the mitochondrial permeability transition pore, mPTP. Activation of the voltage-gated mPTP depolari...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs