William Ja Joins Scripps Florida

By Eric Sauter

The Scripps Research Institute has named William Ja as an assistant professor in the Department of Metabolism and Aging on the institute's Florida campus.

Ja, who was a National Institutes of Health (NIH) postdoctoral fellow in biology at the California Institute of Technology in Pasadena before joining Scripps Florida, is focused on researching various longevity-enhancing manipulations and their impact on aging and metabolism in Drosophila, the common fruit fly and one of the most widely used laboratory models. Among these manipulations are dietary restriction, and the effects on their hosts of certain types of bacteria that live in the gastrointestinal tract.

Ja, who is 32 and lives in Jupiter, officially joined the Scripps Florida faculty in January 2010.

"Bill Ja's recent studies of aging and nutrition in the fruit fly have been innovative and outstanding," said Roy Smith, chair of the Metabolism and Aging Department at Scripps Florida. "His most recent work has shown some novel ways to extend the lifespan of these organisms that could one day provide new tools to help us better understand the aging process and to control the diseases associated with it. We're glad he decided to join us and we want to extend him a warm welcome."

"I'm excited about joining Scripps Florida," Ja said. "It's one of the few places that combines basic and translational research with the advantages of advanced high-throughput screening technology. It's also one of the few places with serious and extensive research into the phenomenon of aging. The possibilities for collaboration with other faculty members are numerous, both in the Department of Metabolism and Aging and at Scripps Research as a whole, and I'm looking forward to exploring those opportunities."

In a 2009 study published in the journal Proceedings of the National Academy of Sciences, Ja and colleagues found that previous observations of a lifespan-increasing effect of dietary restriction turn out to have been a lifespan-reducing effect of dehydration on a diet of more concentrated food. Their results potentially compromise the findings from many previous studies. When dehydration stress is eliminated as a factor, the researchers suggest that the ratio of protein to carbohydrates in the diet of the fruit fly is the primary determinant of its lifespan—a possible model for future mammalian studies.

"Studies on the fruit fly have identified changes in metabolism and gene expression in response to dietary restriction," Ja said. "That's important because some of these changes also occur in humans. Now that we know what changes occur, we can use Scripps Florida's high-throughput screening technology to look for potential drugs that cause the same changes as dietary restriction. Once you find these, you can you test for their potential effect on longevity in model organisms."

In 2008, Ja was awarded a National Institutes of Health Pathway to Independence grant to study the role of bacteria in the development and lifespan of the fruit fly.

"Gastrointestinal bacteria are critical to human health," he said. "In fact, there are ten times more bacterial cells found in our gut than human cells in our entire body. The trouble is, most cannot be grown and studied in the laboratory. We want to develop the fruit fly as a model to test some of these bacteria. Flies carry relatively few species of bacteria—around ten—and that should provide a simpler model for studying host-microbe interactions and lead to directions for future development. Think of all the probiotic microorganisms used in foods like yogurt, for example."

In addition to his scientific work at Caltech, Ja was also involved in sports, and was the assistant coach for the university's NCAA D-III women's volleyball team and head coach of Pasadena Polytechnic School's varsity boys' team.

Send comments to: mikaono[at]scripps.edu

Assistant Professor William Ja is interested in understanding the impact of dietary restriction and certain types of gastrointestinal bacteria on aging and metabolism. (Photo by James McEntee.)