Alzheimer's disease (AD) is the most frequent cause of age-related neurodegeneration and
cognitive impairment, and there are currently no broadly effective
therapies. The underlying pathogenesis is complex, but a growing body of evidence implicates
mitochondrial dysfunction as a common pathomechanism involved in many of the hallmark features of the AD brain, such as formation of
amyloid-beta (Aβ) aggregates (
amyloid plaques), neurofibrillary tangles,
cholinergic system dysfunction, impaired synaptic transmission and plasticity, oxidative stress, and
neuroinflammation, that lead to neurodegeneration and
cognitive dysfunction. Indeed,
mitochondrial dysfunction concomitant with progressive accumulation of mitochondrial Aβ is an early event in AD pathogenesis. Healthy mitochondria are critical for providing sufficient energy to maintain endogenous neuroprotective and reparative mechanisms, while disturbances in mitochondrial function, motility, fission, and fusion lead to neuronal malfunction and degeneration associated with excess
free radical production and reduced intracellular
calcium buffering. In addition,
mitochondrial dysfunction can contribute to
amyloid-β precursor
protein (APP) expression and misprocessing to produce pathogenic fragments (e.g., Aβ1-40). Given this background, we present an overview of the importance of mitochondria for maintenance of neuronal function and how
mitochondrial dysfunction acts as a driver of
cognitive impairment in AD. Additionally, we provide a brief summary of possible treatments targeting
mitochondrial dysfunction as therapeutic approaches for AD.