Stephen E. Alway, Principal Investigator
Project Name: Muscle Regeneration and Repair in Obesity and Aging
Description: Genetic regulation of muscle mass and muscle repair is studied in obese and aging mice. The animals are fed a high fat diet to induce obesity and subjected to reduced activity, or increased activity. Muscle repair is suppressed with both aging and obesity. In this project we activate specific metabolic pathways through genetic and molecular means and study the signaling outcomes from whole muscle to single gene levels. Physiological, biochemical, and molecular approaches are used to evaluate muscle function and protein and gene signaling of molecules through various metabolically regulated pathways that are activated during muscle repair. This project provides us an opportunity to identify strategies for improving muscle function and fatigue, improve muscle mass in obesity which will improve conditions like the Metabolic Syndrome, and increase the capacity for muscles to repair and regenerate in obese and old mice.
Statement of Importance: Obesity has become a significant global health concern that crosses all age groups. Obesity is often associated with greater fatigability and this discourages obese people from engaging in physical activity, which in turn feeds a cycle of lower caloric expenditure and increased adiposity. Thus treating fatigability is clinically important in the battle to reduce obesity, as reducing fatigability would increase the likelihood of prolonging exercise treatment, thereby increasing total caloric expenditure and reversing the consequences of obesity. The condition of aging-associated loss of skeletal muscle mass and function (sarcopenia) increases the susceptibility for obesity and diabetes.This project seeks to identify strategies to reduce fatigability and improve muscle function and mass in aging and obesity, thereby reducing the prevalence of diabetes and other metabolic disorders in older persons.
Students: Matthew Myers, Matthew Brooks, and David Stanton
Post Docs: Junaith S. Mohamed, Ph.D.
Project Name: Reducing Fatigue and Improving Cardiovascular and Muscle Function in Elderly men and Women
Description: Skeletal muscle mass decreases and muscle fatigue increases in obesity and this is further elevated in aging. Although exercise is one means to counter obesity, obese individuals exercise very little because they become fatigued and feel tired quickly. In this project we are testing the efficacy of exercise coupled to various nutritional compounds to determine if they will improve muscle function and fatigue more than with exercise alone.
In this project we have identified men and women who are both older than 65 years and are obese. These subjects exercise from 12 weeks to 9 months, and take either a placebo or a nutritional compound. We evaluate blood parameters for metabolic risk, body composition, muscle strength and fatigue, cardiorespiratory fitness/oxygen consumption, and muscle volume. We also obtain muscle volume (via magnetic resonance imaging) and muscle biopsies to evaluate the effects of these interventions on muscle fiber size and specific genes that we think are important in regulating the molecular pathways of interest.
Statement of Importance: Obesity has become a significant global health concern and it negatively impacts life expectancy and quality of life in older persons. Obesity typically induces greater fatigability and this discourages obese people from engaging in physical activity. This project is designed to improve the expected health benefits and outcomes that might be experienced from exercise alone in obese elderly men and women.
Students: Benjamin Frear, Matthew Myers, Matthew Brooks, and David Stanton
Post Docs: Junaith S. Mohamed, Ph.D.
Collaborators: Mathew Lively, MD, Paul Chantler, Ph.D., Randall Bryner, EdD., Jean McCrory, Ph.D., Diana Gilleland, Daniel Bonner, David Donley, James Thomas