Mitochondria are organelles within cells that are largely responsible for converting metabolic fuel into a form of energy that can be used by the rest of the cell. The long term objective of this research is to understand the role of mitochondrial function/dysfunction may play in the etiology of metabolic disease. The overriding hypothesis of this project is that the nutritional imbalance in skeletal muscle created by an oversupply of metabolic substrates (""""""""over nutrition"""""""", particularly from high fat diets) coupled with low energy demand (sedentary lifestyle) increases the propensity for mitochondrial hydrogen peroxide generation and emission, representing the potential primary factor for the decrease in insulin sensitivity associated with diet-induced obesity. Using a novel approach to study mitochondrial function in human myofibers in situ, the Specific Aims of this project are: 1) to determine the impact of obesity on the regulation of mitochondrial function, cellular redox balance and insulin sensitivity in skeletal muscle of sedentary lean verses obese young adults;2) to determine how high calorie/high fat intake in lean humans acutely and/or chronically affects mitochondrial function, cellular redox balance and insulin sensitivity;3) to determine whether increased physical activity restores redox balance and insulin sensitivity in obese individuals or in lean individuals consuming a high calorie/high fat diet;and 4) to investigate in cultured human primary myotubes whether mitochondrial ROS emission is a primary cause of lipid-induced insulin resistance.

Public Health Relevance

This research seeks to identify the mechanism(s) by which metabolic imbalance caused by over nutrition and physical inactivity leads to altered mitochondrial function and insulin resistance in skeletal muscle of humans. This is highly significant, as a fundamental understanding of the causes of insulin resistance is necessary in order to devise adequate preventive measures and treatments to reduce the health and financial impact of the obesity and diabetes epidemics.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
1R01DK074825-01A2
Application #
7583365
Study Section
Clinical and Integrative Diabetes and Obesity Study Section (CIDO)
Program Officer
Laughlin, Maren R
Project Start
2009-02-16
Project End
2014-01-31
Budget Start
2009-02-16
Budget End
2010-01-31
Support Year
1
Fiscal Year
2009
Total Cost
$343,900
Indirect Cost
Name
East Carolina University
Department
Miscellaneous
Type
Other Domestic Higher Education
DUNS #
607579018
City
Greenville
State
NC
Country
United States
Zip Code
27858
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