The Glenn Center for Aging Research

Today the explorers are scientists, and the uncharted territory they’re searching is confined to the laboratory, but their goal is similar in spirit to that of their predecessors: to uncover the mechanisms that cause us to age, with an eye toward counteracting a host of debilitating conditions that rob humans of their health, productivity, and quality of life. While the outward manifestations of growing older—gray hair, wrinkles, stiffening joints, slower response times, “senior moments”—are as well-known as the many products advertised to address them, scientists actually know little about how we age. Yet the incentive to uncover the secrets of aging is powerful: Advancing age is the single greatest risk factor for most human diseases, from arthritis and cancer to diabetes and neurodegenerative disorders. At the Salk Institute, faculty are particularly focused on the causes and possible treatments for age-related neurodegenerative disorders such as Alzheimer’s, Parkinson’s, and Huntington’s diseases, as well as on genetic and metabolic changes that take place as organisms grow old. Working individually and collaboratively across labs and disciplines, they are continuing to uncover novel insights that expand knowledge and promise to enhance quality of life for an aging population. This issue of From the Bench offers a sampling of their recent findings. BY ITS verY nATure, AgIng research is an interdisciplinary pursuit. In January 2009, catalyzed by a $5 million gift from the glenn Foundation for Medical research, the Salk Institute took a major step forward when it organized its diverse aging research programs within a new entity, the glenn Center for Aging research. under the leadership of Andrew Dillin, the center facilitates aging research from nine of the Institute’s leading laboratories to address fundamental questions in the field, including what constitutes a healthy life span and whether there is a defined biological aging process that is universal to all organisms. glenn Center members specialize in three main areas of investigation. The genetic Analysis group capitalizes on faculty expertise in a variety of cell types to explore new questions about key genetic pathways involved in cell maintenance and aging and to investigate how newly defined genes alter the aging process. The Stem Cell group explores the specific molecular components associated with aging in stem cells, elucidating how stem cells stay healthy, which could explain why and how humans age. The Metabolism group seeks to understand the molecular underpinnings of decreased metabolism and the aging process—specifically, how aging affects metabolism across key organ systems and how restrictive diets can alter genetic expression. In coming years, their combined capabilities promise to add significant momentum to aging research at the Institute and beyond, expanding scientific understanding of a universal, and inevitable, part of life. The Glenn Center for Aging Research A STeM Cell’S IMMedIATe neIgHBorHood, A SPeCIAlIzed environment known as the stem cell niche, provides crucial support for stem cell maintenance. But just as an older house grows less efficient as its windows and doors weather and its appliances wear out, over time, the level of support in the stem cell niche drops off, diminishing stem cells’ ability to renew themselves. In a study of the testis in the fruit fly Drosophila, a team led by Leanne Jones focused on the influence of aging on the behavior of stem cells in the male germ line. They compared the number of stem cells in young, middle-aged, and old flies, and found that over time, stem cell numbers fell from an average of 8.3 in young flies to 5.1 in old flies. (The average fruit fly lives around 40 days.) When the researchers scrutinized the molecular signals that govern the behavior of stem cells in fruit flies, they found a sharp decline in a growth factor necessary to maintain stem cells. a nurturing environment