Insulin, aging and life expectancy: the controller of supervisors for regulators
In experiments on C.elegans roundworms, scientists at the Joslin Center for the Study of Diabetes, working under the guidance of Dr. Keith Blackwell, demonstrated the previously unknown role of insulin in the aging process. They found that insulin inhibits the SKN-1 protein, an increase in the activity of which is associated with an increase in life expectancy. SKN-1 regulates the so–called phase 2 of the detoxification mechanism - a complex of genes whose protein products protect cells and tissues from the effects of various environmental toxins and oxidative stress caused by an excess of free radicals.
Already in the 1990s, it was found that insulin inhibits the protein-regulator of FOXO gene activity, which plays an important role in diabetes metabolism, suppression of tumor growth and self-renewal of stem cell populations. FOXO regulates the activity of a complex of genes, some of which are involved in the mechanisms of resistance to stress. A decrease in the activity level of the insulin-mediated FOXO signaling mechanism stimulates the activity of the DAF-16 gene, which is part of this complex, which increases resistance to stress and increases life expectancy.
The results of the new study make SKN-1 the second most important regulator of gene activity after FOXO, controlling insulin-mediated mechanisms of resistance to stress and protection against aging. According to the data obtained, the signaling pathways activated under the influence of insulin on SKN-1 and DAF-16 act independently of each other. According to Blackwell, manipulations over the expression of the SKN-1 gene allow changing the lifespan of nematodes.
The authors plan to repeat experiments on mammals in which insulin and insulin-like growth factor-1 have a complex set of effects on various tissues. According to Blackwell, usually the results obtained on C.elegans are confirmed for both mice and humans.
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily
24.03.2008