ATP synthesis revisited: new avenues for the management of mitochondrial diseases.

Mitochondrial dysfunction has been implicated in the development of a wide spectrum of major human diseases, including diabetes mellitus, heart disorders, neurodegeneration and cancer. Several therapeutic approaches targeting mitochondrial function have been applied in most cases without however the desired outcome. The limited effectiveness of these therapeutic schemes is due to the fact that several important aspects of mitochondrial function have not been elucidated as yet, including the detailed mechanism of ATP production. Although it is known that electron transport chain (ETC) is the central machinery responsible for mitochondrial oxidative ATP production, major important functions attributed to ETC are still unresolved while other activities which are in fact carried out by the ETC have been overlooked. This review revisits ATP synthesis providing a detailed account of the experimentally-verified ETC functions focused on the ability of ETC to act as an electro-electric converter, able to accept different electrons from any given energy source (light, food or metals) in order to produce the correct voltage and store it in the form of electrostatic potentials (mitochondrial membrane potential). This stored electric energy, in the order of 3x10(7) V/m, can then be used by F1F0 ATP synthase for ATP production. The present review provides supportive evidence that this ETC function suffices to fully explain the missing parts of ATP production, thus redirecting the current therapeutic schemes for the management of mitochondrial diseases to a more complete and effective avenue.