Mitochondrial biogenesis in organismal senescence and neurodegeneration.

Mitochondrial biogenesis is indispensable for organismal homeostasis. The semi-autonomous nature of mitochondria renders their biogenesis rather complex, as it requires the contribution of the nucleus, the cytoplasm and the organelle itself. Recently, several transcription regulators, RNA binding proteins and outer mitochondrial membrane (OMM) components have been implicated in the coordination of the process. Both the expression and the abundance of several of these factors are altered during ageing, and their impairment can have diverse, yet principally detrimental, effects on lifespan. These findings converge on the notion that mitochondrial biogenesis is an age-modulated process that, when perturbed, compromises survival. Notably, core brain functions are dependent on mitochondrial metabolite availability. Indeed, emerging evidence indicates that mitochondrial biogenesis regulators play important roles in the onset and progression of severe neurodegenerative syndromes such as AD, PD and HD. These devastating human pathologies remain incurable to date. A better understanding of the mechanisms that govern mitochondrial biogenesis could facilitate the development of effective pharmaceutical interventions against these diseases.