title: Early mitochondrial adaptations in skeletal muscle to diet-induced obesity are strain dependent and determine oxidative stress and energy expenditure but not insulin sensitivity.
abstract: This study sought to elucidate the relationship between skeletal muscle mitochondrial dysfunction, oxidative stress, and insulin resistance in two mouse models with differential susceptibility to diet-induced obesity. We examined the time course of mitochondrial dysfunction and insulin resistance in obesity-prone C57B and obesity-resistant FVB mouse strains in response to high-fat feeding. After 5 wk, impaired insulin-mediated glucose uptake in skeletal muscle developed in both strains in the absence of any impairment in proximal insulin signaling. Impaired mitochondrial oxidative capacity preceded the development of insulin resistant glucose uptake in C57B mice in concert with increased oxidative stress in skeletal muscle. By contrast, mitochondrial uncoupling in FVB mice, which prevented oxidative stress and increased energy expenditure, did not prevent insulin resistant glucose uptake in skeletal muscle. Preventing oxidative stress in C57B mice treated systemically with an antioxidant normalized skeletal muscle mitochondrial function but failed to normalize glucose tolerance and insulin sensitivity. Furthermore, high fat-fed uncoupling protein 3 knockout mice developed increased oxidative stress that did not worsen glucose tolerance. In the evolution of diet-induced obesity and insulin resistance, initial but divergent strain-dependent mitochondrial adaptations modulate oxidative stress and energy expenditure without influencing the onset of impaired insulin-mediated glucose uptake.
authors.affiliation: Division of Endocrinology, Metabolism, and Diabetes, Salt Lake City, Utah 84112, USA. sihem.boudina@hmbg.utah.edu
authors.forename: Sihem
authors.initials: S
authors.lastname: Boudina
authors.forename: Sandra
authors.initials: S
authors.lastname: Sena
authors.forename: Crystal
authors.initials: C
authors.lastname: Sloan
authors.forename: Ali
authors.initials: A
authors.lastname: Tebbi
authors.forename: Yong Hwan
authors.initials: YH
authors.lastname: Han
authors.forename: Brian T
authors.initials: BT
authors.lastname: O'Neill
authors.forename: Robert C
authors.initials: RC
authors.lastname: Cooksey
authors.forename: Deborah
authors.initials: D
authors.lastname: Jones
authors.forename: William L
authors.initials: WL
authors.lastname: Holland
authors.forename: Donald A
authors.initials: DA
authors.lastname: McClain
authors.forename: E Dale
authors.initials: ED
authors.lastname: Abel
mesh_terms: D000222:Adaptation, Physiological; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D015153:Blotting, Western; D059305:Diet, High-Fat / Q000009:adverse effects; D004075:Diglycerides / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D007328:Insulin / Q000097:blood; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008931:Mitochondria, Muscle / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D009765:Obesity / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*; D018384:Oxidative Stress / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors; D014280:Triglycerides / Q000378:metabolism; D000071247:Uncoupling Protein 3
chemical_list: D001786:Blood Glucose; D004075:Diglycerides; D007328:Insulin; D007473:Ion Channels; D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; D014280:Triglycerides; C000604393:Ucp3 protein, mouse; D000071247:Uncoupling Protein 3; D000255:Adenosine Triphosphate; D013482:Superoxide Dismutase