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Mitochondrial DNA has been known to encode 13 proteins. Recently, other short protein coding sequences have been identified, and their products are referred to as mitochondria-derived peptides. [15] The mitochondrial-derived peptide, humanin has been shown to protect against Alzheimer's disease, which is considered an age-associated disease. [16]
Damage to macromolecules such as DNA, RNA, and proteins along with the deterioration of tissues and organs are the basis of aging. Species-specific rates of aging are due to deleterious changes which manifest after the reproductive phase. "Mitochondrial DNA (mtDNA) regulates cellular metabolism, apoptosis and oxidative stress control". [25]
The theory implicates the mitochondria as the chief target of radical damage, since there is a known chemical mechanism by which mitochondria can produce ROS, mitochondrial components such as mtDNA are not as well protected as nuclear DNA, and by studies comparing damage to nuclear and mtDNA that demonstrate higher levels of radical damage on ...
Aging is characterized by a progressive loss of physiological integrity, leading to impaired function and increased vulnerability to death. The hallmarks of aging are the types of biochemical changes that occur in all organisms that experience biological aging and lead to a progressive loss of physiological integrity, impaired function and, eventually, death.
Other genes regulate aging in yeast by increasing the resistance to oxidative stress. Superoxide dismutase, a protein that protects against the effects of mitochondrial free radicals, can extend yeast lifespan in stationary phase when overexpressed. In higher organisms, aging is likely to be regulated in part through the insulin/IGF-1 pathway.
Hayflick suggested that his results in which normal cells have a limited replicative capacity may have significance for understanding human aging at the cellular level. [ 4 ] It has been reported that the limited replicative capability of human fibroblasts observed in cell culture is far greater than the number of replication events experienced ...
One variation of the idea that mutation is the basis of aging, that has received much attention, is that mutations specifically in mitochondrial DNA are the cause of aging. Several studies have shown that mutations accumulate in mitochondrial DNA in infrequently replicating cells with age.
Aubrey David Nicholas Jasper de Grey (/ d ə ˈ ɡ r eɪ /; born 20 April 1963) is an English biomedical gerontologist.He is the author of The Mitochondrial Free Radical Theory of Aging (1999) and co-author of Ending Aging (2007).