Exploring the role of mitochondrial proteins as molecular target in Alzheimer's disease

Brain is a fully differentiated organ and is sensitive towards oxidative damage of various compounds including lipids, proteins, and DNA that occurs during process of normal aging and is mainly due to its high energy metabolism and reduced activity of anti-oxidative defense mechanism. Mitochondria are dynamic ATP-generating organelles which constitutes cellular functions such as regulation of intracellular calcium, bio-energetic processes, and reduction-oxidation of cells. Such functioning is negatively affected due to the presence of amyloid β peptide (Aβ) which is involved in pathogenesis of Alzheimer disease (AD). Aβ interacts with mitochondria and leads to mitochondrial dysfunction. Mitochondrial dysfunction, abnormal interactions, oxidative stress, and mis-folding of synaptic proteins inside nervous system are explored and regarded as primary or initial features in insurgence of pathology (AD and other neurological disease). The major histopathological hallmarks of AD are characterized by presence of these hallmarks intracellularly, its further progression and exacerbation which leads to excessive accumulation of oligomeric as well as fibrillar-β-amyloid peptides (present extracellularly) and accumulation of neurofibrillary tangles intracellularly. The current review will focus on alterations and variation in mitochondria/mitochondrial DNA (mtDNA) and the rationale for involvement of related abnormalities in pathogenesis of AD.