Rajindar S. Sohal, the Timothy Chan Professor in the USC School of Pharmacy Department of Pharmacology and Pharmaceutical Sciences, has received a five-year renewal grant from the National Institutes of Health that extends support for this particular project to 23 consecutive years.

Sohal and his associates are trying to answer the age-old question: What causes aging and what strategy can we use to counter its effects?

Their exploration focuses on how the production of free radicals and other oxidants in the body contribute to aging. Using the fruit fly as the research model, Sohal’s current project builds on past efforts, including recent findings that discounted the idea that the more antioxidants the better.

“A great deal of work has been done in our lab and around the world that implicates free radicals and other oxidants as contributors to the aging process. It was previously believed that augmentation of antioxidants would counteract oxidative stress,” Sohal said. “However, this approach has yielded only ambiguous results. Now, we will focus on controlling the production of radicals in the mitochondria, the main site of energy production in our cells and a major site of free radical production.”

The free radicals are actually by-products of oxygen utilization needed for energy generation. To control production of free radicals in the mitochondria, Sohal will modify the electron transport component, Cytochrome-c oxidase. Typically, this mitochondrial enzyme becomes less abundant during the aging process.

Sohal hypothesizes that by inserting extra copies of some of the genes encoding Cytochrome-c oxidase into cells – maintaining levels comparable to those in youth – should decrease the production of free radicals. This decreased production should minimize damage and thus slow the aging process.

When asked about this next step in his research, Sohal said, “One is never sure where research will take him. However, we do know that our hypothesis is built on a sound foundation.”

Sohal uses the fruit fly for his research because it provides an advanced model for genetic manipulation and has a short life span. This is an excellent combination for the study of aging – offering an organism with well-understood genetics and an efficient way to test theories across generations due to the short life span.

“This phase in our research may take us a bit closer to understanding the mysterious process of aging,” Sohal said. “Having studied aging for 40 years, I have learned one thing for sure. Enjoy yourself while you’re alive because we are all aging and going to die,” he added with a laugh.