Senior scientist and Buck Institute professor Judith Campisi, PhD, said the finding sheds light on current apparent discrepancies regarding the role of free radicals as a driver of the aging process. Free radicals are especially reactive atoms or groups of atoms that have one or more unpaired electrons. They are produced in the body as a
«This study shows that it’s essential that we look across the entire lifespan when we examine mechanisms implicated in the aging process," Campisi said, adding that while increased free radical production showed benefit in younger animals, the mice paid a price over time. Campisi said mitochondrial damage from excess free radicals caused some of the skin cells to go into senescence — they stopped dividing and started accumulating. Campisi said that over time the energy available to the epidermal stems cells was depleted — the stem cells simply became too scarce and the mice showed expected signs of aging, thin skin and poor wound healing. «In this case, we found unexpected pleotropic effects, mechanisms that benefit us when we’re young, cause problems as we age.»
Campisi said the mice used in this study more closely mimic the stress that occurs over time in human skin. «Mice are nocturnal and covered with fur; in their life, and in normal laboratory conditions, they don’t experience the type of sun
In addition to the complications caused by senescence, lead scientist Michael Velarde, PhD, a postdoctoral fellow in the Campisi lab, said mitochondrial stress caused by the increase in free radicals also forced the skin cells in the younger animals to differentiate faster than normal, further depleting the pool of stem cells available to renew the skin over time. «This is not a simple process. It may be that nature used free radicals to optimize skin health, but because this process is not deleterious to the organism until later in life, past its reproductive age, there was no need to evolve ways to alter this mechanism," he said.
Campisi said there could be one practical implication of the study: taking large amounts of
Citation: Proceedings of the National Academy of Sciences: Pleiotropic
Other Buck Institute researchers involved in the study include Simon Melov and Marco Demaria. This work was supported by grants from the National Institutes of Health: AG09909, AG18679, AG025901, and AG041221.
About the Buck Institute for Research on Aging
The Buck Institute is the U.S.’s first independent research organization devoted to Geroscience — focused on the connection between normal aging and chronic disease. Based in Novato, CA, The Buck is dedicated to extending «Healthspan», the healthy years of human life and does so utilizing a unique interdisciplinary approach involving laboratories studying the mechanisms of aging and those focused on specific diseases. Buck scientists strive to discover new ways of detecting, preventing and treating
