Researchers at the Joslin Diabetes Center found that insulin has a previously unknown effect on SKN-1, which plays a role in aging and lifespan. They showed that insulin’s impact on thsi pathway is independent of insluin’s effect on a gene-regulator protein known as FOXO, which is important in diabetes metabolism, tumor suppression, and stem cell maintenance.
In their study of C. elegans, the researchers showed that insulin inhibits a master gene-regulator protein known as SKN-1 and that heightened SKN-1 activity increases lifespan. SKN-1 controls the Phase 2 detoxification pathway, a network of genes that defends cells and tissue against oxidative stress and various environmental toxins.
“This has implications for basic biology since under some circumstances insulin may reduce defense against the damaging effects of oxidative stress more than we realize,” says T. Keith Blackwell, M.D., Ph.D., senior investigator at Joslin and author of the paper. “The major implication is that we have found something new that affects lifespan and aging and an important new effect that insulin and/or a related hormone called insulin-like growth factor-1 may have in some tissues.”
The paper will be published in the March 21 issue of Cell.