LeBris S. Quinn, Ph.D.
Emeritus Research Associate Professor
Research Interests: During normal aging, individuals typically lose about one-third of their muscle tissue, with accompanying losses in strength and endurance. The age-associated decline in muscle tissue is termed “sarcopenia” by geriatricians. Sarcopenia is a major cause of frailty, falls, and loss of independence in the elderly. Research conducted in Dr. Quinn’s laboratory has focused on the underlying cellular and biochemical mechanisms of the age-associated loss of skeletal muscle. An understanding of the biochemical bases of these conditions will enable design of treatments for sarcopenia and frailty in the elderly.
In additon to the loss of skeletal muscle, another important change during normal aging is the increased deposition of adipose tissue. Together with sarcopenia, the increase in fat:lean body composition predisposes the elderly to development of insulin resistance, metabolic syndrome, and type-2 diabetes, major factors in death and disability in the aged population. These, in turn, are risk factors for cardiovascular disease, cancer, and Alzheimer’s disease.
Physical activity is an effective preventive measure and treatment for obesity and insulin resistance because it initiates a pattern of gene expression that promotes fat oxidation, which in turn improves endurance, body composition, and insulin sensitivity. However, due to injury or disability, not all elderly individuals can engage in exercise. Over the past ten years, Dr. Quinn’s laboratory has pioneered research on interleukin-15 (IL-15), a cytokine that is upregulated in skeletal muscle following exercise and correlates with leanness and insulin sensitivity. Studies in laboratory rodents showed that IL-15 release from muscles is the “trigger” for the positive metabolic effects of exercise, and that IL-15 is required for the gene expression changes that occur following exercise. Other studies showed that IL-15 levels in muscle decline during normal aging, possibly accounting for the decreased efficacy of exercise in the elderly. This research may lead to development of a pharmacological exercise mimetic.
College: 1976, Swarthmore College
Graduate School: 1982, Ph.D., Biological Structure, University of Washington
Postdoctoral Training: 1983-1986, University of Washington
Publications: Go to PubMed.
Community of Science: Click to go to Dr. Quinn's Community of Science page.
General Information: Email Dr. Quinn.