Role of mitochondria in aging and age-related disease

Aging Cell, 2004

Science of Aging Knowledge …, 2005

Biochimie, 1998

Biochimie { i t)98) 80, 863=870 ~,,) SociOt6 fran~:aise de biochimic et bi~logic moK'cutaire / Ik3sevieL Paris

Science of aging knowledge environment : SAGE KE, 2006

The European research project MiMage, supported by the European Community's Sixth Framework for Research and Technological Development, focuses on elucidating the role of mitochondria in conserved mechanisms of aging. This Perspective summarizes a selection of talks presented in April 2006 at the second MiMage symposium by members from participating laboratories and invited speakers.

Journal of Biomedical Science, 1997

Mitochondria are the major intracellular source and target sites of reactive Reactive oxygen species oxygen species (ROS) that are continually generated as by-products of aerobic Mitochondria metabolism in animal and human cells. It has been demonstrated that mito-Mitochondrial DNA chondrial respiratory function declines with age in various human tissues and Mutation that a defective respirators" chain results in enhanced production of ROS and Aging free radicals in mitochondria. On the other hand, accumulating evidence now indicates that lipid peroxidation, protein modification and mitochondrial DNA (mtDNA) mutation are concurrently increased during aging. On the basis of these observations and the fact that the rate of cellular production of superoxide anions and hydrogen peroxide increases with age, it has recently been postulated that oxidative stress is a major contributory factor in the aging process. A causal relationship between oxidative modification and mutation ofmtDNA, mitochondrial dysfunction and aging has emerged, although some details have remained unsolved. In this article, the role of mitochondria in the human aging process is reviewed on the basis of recent findings gathered from our and other laboratories.

The journals of gerontology. Series A, Biological sciences and medical sciences, 2015

Mitochondrial dysfunction has long been considered a major contributor to aging and age-related diseases. Harman's Mitochondrial Free Radical Theory of Aging postulated that somatic mitochondrial DNA mutations that accumulate over the life span cause excessive production of reactive oxygen species that damage macromolecules and impair cell and tissue function. Indeed, studies have shown that maximal oxidative capacity declines with age while reactive oxygen species production increases. Harman's hypothesis has been seriously challenged by recent studies showing that reactive oxygen species evoke metabolic health and longevity, perhaps through hormetic mechanisms that include autophagy. The purpose of this review is to scan the ever-growing literature on mitochondria from the perspective of aging research and try to identify priority questions that should be addressed in future research. A systematic search of peer-reviewed studies was performed using PubMed. Search terms inc...

Annals of the New York Academy of Sciences, 1996

BioMed Research International, 2014

Age-related changes in mitochondria are associated with decline in mitochondrial function. With advanced age, mitochondrial DNA volume, integrity and functionality decrease due to accumulation of mutations and oxidative damage induced by reactive oxygen species (ROS). In aged subjects, mitochondria are characterized by impaired function such as lowered oxidative capacity, reduced oxidative phosphorylation, decreased ATP production, significant increase in ROS generation, and diminished antioxidant defense. Mitochondrial biogenesis declines with age due to alterations in mitochondrial dynamics and inhibition of mitophagy, an autophagy process that removes dysfunctional mitochondria. Age-dependent abnormalities in mitochondrial quality control further weaken and impair mitochondrial function. In aged tissues, enhanced mitochondria-mediated apoptosis contributes to an increase in the percentage of apoptotic cells. However, implementation of strategies such as caloric restriction and regular physical training may delay mitochondrial aging and attenuate the age-related phenotype in humans.

Free Radical Biology and Medicine, 2003

Mitochondria are both a major source of oxidants and a target for their damaging effects, and, therefore, mitochondrial oxidative stress appears to be a cause, rather than a consequence, of cell aging. Oxidative damage in aging is particularly high in specific molecular targets, such as mitochondrial DNA and aconitase, and mitochondrial oxidative stress may drive tissue aging through intrinsic apoptosis. Mitochondrial function and morphology are impaired upon aging, as judged by a decline in membrane potential as well as by an increase in peroxide production and size of the organelles. In view of the age-related decreases in mitochondrial protein synthesis, mitochondrial transcripts, and expression of genes involved in mitochondrial turnover, the rate of this turnover might determine its susceptibility of mitochondria to oxidative damage and mutation, thus controlling the rate of cell aging. In fact, aging is a feature of differentiated somatic cells, especially postmitotic cells such as neurons or muscle cells. The age-associated mitochondrial DNA deletions focally accumulate in brain and skeletal muscle, thus contributing significantly to aging of these postmitotic tissues. Expansion of mitochondrial DNA mutations may occur through mitochondrial complementation. The use of mutants of the mitochondrial electron transport system, as well as knockouts or transgenics of mitochondrial antioxidants or repair enzymes, may provide clear-cut evidence of the precise mitochondrial mechanisms that control the rate of cell aging.

Biogerontology, 2015

Ageing is accompanied by the accumulation of damaged molecules in cells due to the injury produced by external and internal stressors. Among them, reactive oxygen species produced by cell metabolism, inflammation or other enzymatic processes are considered key factors. However, later research has demonstrated that a general mitochondrial dysfunction affecting electron transport chain activity, mitochondrial biogenesis and turnover, apoptosis, etc., seems to be in a central position to explain ageing. This key role is based on several effects from mitochondrial-derived ROS production to the essential maintenance of balanced metabolic activities in old organisms. Several studies have demonstrated caloric restriction, exercise or bioactive compounds mainly found in plants, are able to affect the activity and turnover of mitochondria by increasing biogenesis and mitophagy, especially in postmitotic tissues. Then, it seems that mitochondria are in the centre of metabolic procedures to be modified to lengthen lifeor health-span. In this review we show the importance of mitochondria to explain the ageing process in different models or organisms (e.g. yeast, worm, fruitfly and mice). We discuss if the cause of aging is dependent on mitochondrial dysfunction of if the mitochondrial changes observed with age are a consequence of events taking place outside the mitochondrial compartment.