Bioenergetics breakdown in Alzheimer's disease: targets for new therapies.

Alzheimer's disease is rapidly growing worldwide and yet there is no cure for it. Currently available drugs only provide symptomatic relief and do not intervene in disease process sufficiently enough to prevent or cure it. Characteristic features of this disease are decline in neuronal mass and cognitive functions. The most dominant hypothesis proposed for pathogenesis of this disease is called "amyloid hypothesis". It states that excessive production of amyloid peptides called abeta peptides (Aβ) is the underlying cause of neuronal death and dysfunction. However, recent drugs designed based on amyloid hypothesis have failed in clinical trails, demanding fresh assessment. Early and persistent molecular events in this disease progression are energy deficiency and high oxidative stress in the neurons. Our review will put together a disease model based on known human and animal data with regards to breakdown in neuronal energy generation. The model will integrate energy deficits as the cause of neuronal dysfunction and abeta peptide production culminating in catastrophic loss of cognitive functions. Finally, based on this model, we will also suggest enzyme targets in neuronal bioenergetics pathway for design and development of new disease modifying therapies.