Fight Aging! Newsletter, May 13th 2013

In this study we used the hMTH1-Tg mouse model to investigate how oxidative damage to nucleic acids affects aging. hMTH1-Tg mice express high levels of the hMTH1 hydrolase that degrades 8-oxodGTP and 8-oxoGTP and excludes 8-oxoguanine from both DNA and RNA. Compared to wild-type animals, hMTH1-overexpressing mice have significantly lower steady-state levels of 8-oxoguanine in both nuclear and mitochondrial DNA of several organs, including the brain. hMTH1 overexpression prevents the age-dependent accumulation of DNA 8-oxoguanine that occurs in wild-type mice.

These lower levels of oxidized guanines are associated with increased longevity and hMTH1-Tg animals live significantly longer than their wild-type littermates. Neither lipid oxidation nor overall antioxidant status are significantly affected by hMTH1 overexpression. The significantly lower levels of oxidized DNA/RNA in transgenic animals are associated with behavioral changes. These mice show reduced anxiety and enhanced investigation of environmental and social cues.

There some muddying of the water here, of course. Nothing is ever simple in biology. The first item to consider is that it's possible that differences in activity levels in the mice could account for some of the longevity differences shown in the research. This is hard to control for, harder than calorie restriction, which is the other thing you have to keep track of in any mouse study. If your mice happen to eat less because your treatment makes them n...

Source: Fight Aging! - May 12, 2013 Category: Health Medicine and Bioethics Commentators Authors: Reason Tags: Newsletters Source Type: blogs