R01AG074502

Determining the Context Specificity of Metformin Treatment on Muscle Mitochondria and Healthspan - Summary

Metformin, the most widely prescribed medication for treating type 2 diabetes, is increasingly recognized for its healthspan effects that resemble exercise. The beneficial effects of metformin, like aerobic exercise, appear to be mediated through an energetic and/or redox stress mechanism, raising the prospect that the two approaches could exert additive or even synergistic effects.

Surprisingly, our recently published clinical trial showed that metformin inhibits the beneficial effects of aerobic exercise training (AET) on skeletal muscle mitochondrial function and whole-body insulin sensitivity. Interestingly, subjects who entered the study with the highest mitochondrial complex I supported OXPHOS function and insulin sensitivity were the most negatively affected by metformin treatment. How metformin inhibits the positive effects of AET, why this effect is most pronounced in those with the highest mitochondrial function, and how these interactions ultimately impact healthspan and lifespan are unknown.

The hypothesis of this proposal is that the effects of metformin on healthspan and lifespan are context specific; beneficial in the context of low energy demand/mitochondrial capacity but detrimental in the context of high energy demand/mitochondrial capacity. To test this hypothesis, the study will leverage a rat model with divergent selection for intrinsic aerobic capacity, referred to as high capacity and low capacity runners (HCR/LCR). By selecting for maximal treadmill running capacity, LCR and HCR rats diverged in intrinsic mitochondrial function, lifespan, and metabolic traits that increase or decrease the risk for chronic disease.

Changes in mitochondrial function will be assessed using ex vivo respirometry that measures the interplay among three thermodynamic forces. Further, the proposal uses targeted kinetic and quantitative mitochondrial proteomics to understand appropriate or aberrant cellular remodeling, and novel in vivo imaging approaches to understand changes in mitochondrial morphology and dynamics.

The specific aims are to:
1) Establish if mitochondrial changes to metformin treatment are context specific,
2) Establish if the effects of metformin on adaptations to aerobic exercise training are context specific, and
3) Determine whether the beneficial effects of metformin on healthspan and lifespan are context specific.

It is expected that with metformin treatment, remodeling of mitochondria will be consistent with improved outcomes in LCR rats, but have no effect or will be detrimental in HCR, with or without exercise training. Further, it is expected that metformin will extend healthspan and lifespan in LCR rats, but not HCR rats.

Successful completion of these aims will reveal the importance of context specificity on metformin action and the mechanisms underlying its positive and potentially negative impacts on healthspan and lifespan. This information is critical given the ever-expanding off-target use of metformin in healthy individuals without chronic disease and/or overt metabolic dysfunction. Results from this project will help inform who can benefit from metformin treatment, and more importantly, who should avoid it.

Oklahoma Medical Research Foundation

TO ENCOURAGE BIOMEDICAL, SOCIAL, AND BEHAVIORAL RESEARCH AND RESEARCH TRAINING DIRECTED TOWARD GREATER UNDERSTANDING OF THE AGING PROCESS AND THE DISEASES, SPECIAL PROBLEMS, AND NEEDS OF PEOPLE AS THEY AGE. THE NATIONAL INSTITUTE ON AGING HAS ESTABLISHED PROGRAMS TO PURSUE THESE GOALS. THE DIVISION OF AGING BIOLOGY EMPHASIZES UNDERSTANDING THE BASIC BIOLOGICAL PROCESSES OF AGING. THE DIVISION OF GERIATRICS AND CLINICAL GERONTOLOGY SUPPORTS RESEARCH TO IMPROVE THE ABILITIES OF HEALTH CARE PRACTITIONERS TO RESPOND TO THE DISEASES AND OTHER CLINICAL PROBLEMS OF OLDER PEOPLE. THE DIVISION OF BEHAVIORAL AND SOCIAL RESEARCH SUPPORTS RESEARCH THAT WILL LEAD TO GREATER UNDERSTANDING OF THE SOCIAL, CULTURAL, ECONOMIC AND PSYCHOLOGICAL FACTORS THAT AFFECT BOTH THE PROCESS OF GROWING OLD AND THE PLACE OF OLDER PEOPLE IN SOCIETY. THE DIVISION OF NEUROSCIENCE FOSTERS RESEARCH CONCERNED WITH THE AGE-RELATED CHANGES IN THE NERVOUS SYSTEM AS WELL AS THE RELATED SENSORY, PERCEPTUAL, AND COGNITIVE PROCESSES ASSOCIATED WITH AGING AND HAS A SPECIAL EMPHASIS ON ALZHEIMER'S DISEASE. SMALL BUSINESS INNOVATION RESEARCH (SBIR) PROGRAM: TO EXPAND AND IMPROVE THE SBIR PROGRAM, TO INCREASE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, TO INCREASE SMALL BUSINESS PARTICIPATION IN FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. SMALL BUSINESS TECHNOLOGY TRANSFER (STTR) PROGRAM: TO STIMULATE AND FOSTER SCIENTIFIC AND TECHNOLOGICAL INNOVATION THROUGH COOPERATIVE RESEARCH DEVELOPMENT CARRIED OUT BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO FOSTER TECHNOLOGY TRANSFER BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO INCREASE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION.

93.866 - Aging Research

National Institute on Aging (NIA) [HHS - NIH]

Oklahoma City, Oklahoma 731045005 United States

Single Zip Code

NIH Research Project Grant (Parent R01 Clinical Trial Not Allowed) (PA-20-185)

Amendment Since initial award the total obligations have increased 368% from $651,808 to $3,047,633.