The most popular theory of aging is the free radical theory, which dictates that cumulative damage in intracellular components from reactive oxygen species causes aging and age related disease.
As such researchers continue to unravel the methods cells use to mitigate this damage for the potential to exploit them in clinical use.
In the current study, researchers show for the first time a unique class of molecules called sestrins are able to positively regulate lifespan.
Sestrins are molecules which reverse a reaction occurring in molecules called peroxiredoxins which themselves neutralize free radical damage. By reversing this reaction, sestrins act to recycle peroxiredoxins to continue their antioxidant functioning. In this way they act as intracellular antioxidants.
In the current study, researcher analyzed the function of the single sestrin gene found in C. Elegans nematodes. There are three homologous genes in humans.
First they genetically modified worm to over-express sesn-1. Those worms then were observed to have lengthened lifespan. If the sesn-1 gene was mutated, the worms had shorter lifespnas.
In addition to shorter lifespans, the worms with mutated sesn-1 had higher ROS levels in response to environmental stresses and showed signs of muscle degeneration.
“Although more remains to be learned, our results have established that SESN-1 is a critical link
between longevity and stress and regulates lifespan,” write the authors.
A next step might be to see if sestrin activators can also increase lifespan in mammals, perhaps one day including humans.