Source: MakeLemonade.nz
Te Whanganui-a-Tara – New scientific research furthers the argument for exercise in promoting youthfulness in people.
A recent paper published in the Journal of Physiology has deepened the case for the youthfulness-promoting effects of exercise on ageing organisms, building on previous work.
The densely detailed study was carried out by 16 research academics from the University of Arkansas.
For their paper, the researchers compared ageing mice that had access to a weighted exercise wheel with mice that had undergone epigenetic reprogramming via the expression of Yamanaka factors.
The Yamanaka factors are four protein transcription factors that can revert highly specified cells, such as a skin cell, back to a stem cell, which is a younger and more adaptable state.
The Nobel Prize in Physiology or Medicine was awarded to Dr Shinya Yamanaka for the discovery in 2012. In the correct dosages, inducing the Yamanaka factors throughout the body in rodents can ameliorate the hallmarks of ageing by mimicking the adaptability that is common to more youthful cells.
The four factors are identified as Oct3/4, Sox2, Klf4 and c-Myc, or often abbreviated to OKSM). Myc is induced by exercising skeletal muscle. Myc may serve as a naturally induced reprogramming stimulus in muscle, making it a useful point of comparison between cells that have been reprogrammed.
Cells that have been reprogrammed through exercise can alter the accessibility and expression of genes.
The researchers compared the skeletal muscle of mice who had been allowed to exercise late in life to the skeletal muscle of mice that overexpressed OKSM in their muscles, as well as to genetically modified mice limited to the overexpression of just Myc in their muscles.
Ultimately, the team determined that exercise promotes a molecular profile consistent with epigenetic partial programming.
Their work showed exercise can mimic aspects of the molecular profile of muscles that have been exposed to Yamanaka factors, thus displaying molecular characteristics of more youthful cells. This beneficial effect of exercise may in part be attributed to the specific actions of Myc in muscle.
First, Myc would never be able to replicate all the downstream effects exercise has throughout the body.
It is also the cause of tumours and cancers, so there are inherent dangers to manipulating its expression. The researchers thinks manipulating Myc might best be employed as an experimental strategy to understand how to restore exercise adaptation to old muscles showing declining responsiveness.
Possibly it could also be a means of supercharging the exercise response of astronauts in zero gravity or people confined to bed rest who only have a limited capacity for exercise. Myc has many effects, both good and bad, so defining the beneficial ones could lead to a safe therapeutic that could be effective for humans down the road.
