ABSTRACT

A major common determinant of the involvement of mitochondria in the aetiology and pathogenesis of so many diseases has been considered their key role in the generation of reactive oxygen species (ROS); although ROS are generated by several other cellular systems, mitochondrial ROS arising from the respiratory chain appear to be strategic for the development of pathological states. Nevertheless, contrary to previous understanding that ROS are deleterious by-products whose production should be avoided, it is now clear that  ROS are physiological messengers acting through redox modications in signalling proteins. For this reason it is believed that ageing may be, at least in part, the result of alterations of signalling pathways such as those involved in mitochondrial biogenesis and apoptosis, induced by an increasing ROS production.4,5

Among the factors controlling ROS generation by mitochondria, it is becoming increasingly clear that a major role is played by the supramolecular structure of mitochondrial respiratory complexes.