Measures of Mitochondrial DNA Damage Lower in Long-Lived Mice

Damage to mitochondrial DNA accumulates as a side-effect of the operation of mitochondria in your cells, and per the mitochondrial free radical theory of aging proceeds to cause some fraction of degenerative aging though a long chain of ever worsening consequences.

Below you'll find recently published research that shows long-lived mice to have less mitochondrial DNA damage, which is what you'd expect to see under this model. This reinforces the need for ways to repair or replace mitochondrial DNA throughout the body in order to remove this contribution to degenerative aging. A wide range of possible approaches exist, but currently little funding is devoted towards realizing them and there is no path to getting treatments to reverse aging through the regulatory process - the standard lament when it comes to rejuvenation biotechnology.

The single gene mutation of Ames dwarf mice increases their maximum longevity by around 40% but the mechanism(s) responsible for this effect remain to be identified. This animal model thus offers a unique possibility of testing the mitochondrial theory of aging.

In this investigation, oxidative damage to mitochondrial DNA (mtDNA) was measured for the first time in dwarf and wild type mice of both sexes. In the brain, 8-oxo,7,8-dihydro-2'-deoxyguanosine (8-oxodG) in mtDNA [a measure of oxidative stress] was significantly lower in dwarfs than in their controls both in males (by 32%) and in females (by 36%). The heart of male dwarfs also showed significantly lower mtDNA 8-oxodG levels (30% decrease) than the heart of male wild type mice, whereas no differences were found in the heart of females.

The results, taken together, indicate that the single gene mutation of Ames dwarfs lowers oxidative damage to mtDNA especially in the brain, an organ of utmost relevance for aging. Together with the previous evidence for relatively lower level of oxidative damage to mtDNA in both long-lived and caloric restricted animals, these findings suggest that lowering of oxidative damage to mtDNA is a common mechanism of life extension in these three different mammalian models.



Here's another very recent finding with implications for mitochondria and ageing:

Failure of mitochondrial quality control seems to be causative for heart failure and Parkinson's disease. Seeing as these are age-related conditions, the defective quality control mechanism probably leads to a more rapid emergence of specific age-related pathologies that would eventually manifest even without the gene defect.

Posted by: José at April 25th, 2013 3:15 PM

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