A recent collaborative study between scientists at the Buck Institute for Research on Aging, the MDI Biological Laboratory, and the Nanjing University in China found an interesting synergetic pathway between the IIS (insulin signaling pathway) and TOR pathway by studying C.elegans: nematodes that share many genes with human beings.
The short lifespan of C.elegans (three to four weeks) allowed the scientists to identify the cellular pathways that regulated aging. The scientists were able to genetically change the IIS and TOR pathways by using a double mutant on the C.elegans. The alterations were expected to yield a 130% increase in the lifespan of the C.elegans, since altering the IIS pathway yields a 100% increase and altering the TOR pathway yields a 30% increase. However, the math didn’t work out, and that’s a good thing! Surprisingly, the lifespan of the C.elegans increased by 500%.
So, even though the scientists discovered the pathways that regulated aging in C.elegans, the nuances of these interactions are still unclear. A paper discussing this topic relates longevity to the mitochondria’s role in maintaining homeostasis. Jarod A. Rollins, one of the authors of the paper, hopes to further clarify and investigate the role of mitochondria on aging in his future research.
Even still, the discover of these cellular pathways could lead to longer lives for humans. Pathways such as these were passed down to humans by evolution (conserved) so, the 500% increase in longevity that occurred in C.elegans after alteration could also occur in humans. Although the way in which these pathways affect each other is unclear, we now know that multiple genes and cellular pathways contribute to the aging process.
How do you think that the IIS and TOR pathways affect each other? If our lifespans are expanded in the future, what will be the moral and societal implications?