title: Mitochondrial DNA oxidative damage and repair in aging and Alzheimer's disease.
abstract: CONCLUSIONS
  Mitochondria are fundamental to the life and proper functioning of cells. These organelles play a key role in energy production, in maintaining homeostatic levels of second messengers (e.g., reactive oxygen species and calcium), and in the coordination of apoptotic cell death. The role of mitochondria in aging and in pathophysiological processes is constantly being unraveled, and their involvement in neurodegenerative processes, such as Alzheimer's disease (AD), is very well known.
  
  
  BACKGROUND
  A considerable amount of evidence points to oxidative damage to mitochondrial DNA (mtDNA) as a determinant event that occurs during aging, which may cause or potentiate mitochondrial dysfunction favoring neurodegenerative events. Concomitantly to reactive oxygen species production, an inefficient mitochondrial base excision repair (BER) machinery has also been pointed to favor the accumulation of oxidized bases in mtDNA during aging and AD progression.
  
  
  RESULTS
  The accumulation of oxidized mtDNA bases during aging increases the risk of sporadic AD, an event that is much less relevant in the familial forms of the disease. This aspect is critical for the interpretation of data arising from tissue of AD patients and animal models of AD, as the major part of animal models rely on mutations in genes associated with familial forms of the disease.
  
  
  CONCLUSIONS
  Further investigation is important to unveil the role of mtDNA and BER in aging brain and AD in order to design more effective preventive and therapeutic strategies.
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
authors.forename: Renato X
authors.initials: RX
authors.lastname: Santos
authors.forename: Sónia C
authors.initials: SC
authors.lastname: Correia
authors.forename: Xiongwei
authors.initials: X
authors.lastname: Zhu
authors.forename: Mark A
authors.initials: MA
authors.lastname: Smith
authors.forename: Paula I
authors.initials: PI
authors.lastname: Moreira
authors.forename: Rudy J
authors.initials: RJ
authors.lastname: Castellani
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nunomura
authors.forename: George
authors.initials: G
authors.lastname: Perry
mesh_terms: D000375:Aging / Q000235:genetics* / Q000378:metabolism; D000544:Alzheimer Disease / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism / Q000473:pathology; D004249:DNA Damage; D004260:DNA Repair; D004272:DNA, Mitochondrial / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D004272:DNA, Mitochondrial; D017382:Reactive Oxygen Species