title: The role of mitochondria in aging of skeletal muscle.
abstract: Aging can be characterized as a time dependent decline of maximal functionality that affects tissues and organs of the whole body. Such is induced by the progressive loss of redundant components and leads to an increased susceptibility to disease and risk of death. Regarding the aging of skeletal muscle, it has been pointed out that mitochondria is a key factor behind the loss of redundancy and functionality, since this organelle has a major role in cellular homeostasis particularly at the level of the bioenergetic status. Decreased activities of the mitochondrial electron transport chain complexes and an increased release of reactive oxygen species from mitochondria are well documented with age; it is suggested that the mitochondrial loss of function results from the increased oxidative damage to proteins, lipids, and DNA of this organelle. However, it is important to be aware that the mitochondrial loss of function could also be a consequence, rather than a cause, of the cellular deterioration with age, which compromises mitochondrial biogenesis, mitochondrial protein turnover and autophagocytosis of damaged mitochondria. In this review several topics will be addressed regarding the age-related loss of skeletal muscle redundancy associated with mitochondrial dysfunction, emphasizing hypotheses for underlying mechanisms. In addition, we discuss some of the cellular mechanisms that can be pointed out as being responsible for the age-related mitochondrial dysfunction.
authors.affiliation: Faculty of Sports, Centro de Investigação em Actividade Física, Saúde e Lazer, R. Dr. Plácido Costa, 91, Porto, 4200-450, Portugal. pascfigueiredo@gmail.com
authors.forename: Pedro Alexandre
authors.initials: PA
authors.lastname: Figueiredo
authors.forename: Maria P
authors.initials: MP
authors.lastname: Mota
authors.forename: Hans Joachim
authors.initials: HJ
authors.lastname: Appell
authors.forename: José Alberto
authors.initials: JA
authors.lastname: Duarte
mesh_terms: D000375:Aging / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D016922:Cellular Senescence; D006801:Humans; D008931:Mitochondria, Muscle / Q000378:metabolism* / Q000473:pathology; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D018384:Oxidative Stress; D010641:Phenotype; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species