Oxidative damage, particularly to proteins, is widely believed to be a major cause of the loss of muscle function during senescence. Researchers have observed decreases in mitochondrial oxidative capacity and enzyme activity with age in muscle, which may be directly related to free radical oxidant production by mitochondria. Several key metabolic enzymes -- phosphofructokinase (rate limiting glycolytic enzyme), two key mitochondrial enzymes (citrate synthase and aconitase) and one electron transport chain enzyme (cytochrome c oxidase) -- have been shown to decline with age in skeletal muscle and heart muscle. The mechanism that produces this decline is unknown and may be related to oxidative damage that occurs with aging in mitochondria. Moreover, the sources of reactive radical species that contribute to protein oxidative damage are poorly understood, primarily because of the non-specific methods used to study protein oxidation. Therefore, we will use sensitive analytical methods (gas chromatography and mass spectrometry) to explore the respective roles of the metal-catalyzed oxidation pathway, the tyrosyl radical mediated pathway, and the reactive nitrogen pathway, which generate specific unnatural amino acids, i.e., o-tyrosine, m-tyrosine, o'-dityrosine, and 3-nitrotyrosine. With this approach the investigators will be able to determine the following: 1) which radical species are responsible for protein damage? 2) is protein damage predominantly caused by mitochondria? 3) to what extent does protein damage accumulate in muscle? 4) do the levels of oxidized amino acids in the urine correlate with those in mitochondria and/or cytosol? And 5) does oxidative protein modification affect enzyme function and mitochondrial functional capacity? To accomplish these aims, these investigators will determine oxidant production, overall oxidative protein and lipid damage, specific enzyme activity, and mitochondrial function of young, adult, and old rats. They will also measure enzyme activity of purified enzymes and the amount of oxidative enzyme damage. Furthermore, they will determine if two protective interventions, caloric restriction and life-long voluntary exercise, can attenuate muscle protein oxidation and restore enzymatic function and mitochondrial function. These experiments will provide the first evidence to answer the following questions:1) are mitochondria major contributors to protein oxidation with aging? 2) are key metabolic enzymes affected by oxidant damage and contribute to the functional decline in muscle with age? 3) does enzyme activity reflect loss of enzyme protein or the accumulation of inactive forms of enzymes? And 4) can enzyme function and mitochondrial functional capacity be restored with caloric restriction and/or daily exercise?

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG017994-02
Application #
6372481
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Program Officer
Carrington, Jill L
Project Start
2000-08-01
Project End
2005-07-31
Budget Start
2001-08-01
Budget End
2002-07-31
Support Year
2
Fiscal Year
2001
Total Cost
$284,879
Indirect Cost
Name
University of Florida
Department
Other Health Professions
Type
Other Domestic Higher Education
DUNS #
073130411
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Picca, Anna; Sirago, Giuseppe; Pesce, Vito et al. (2018) Administration of Enalapril Started Late in Life Attenuates Hypertrophy and Oxidative Stress Burden, Increases Mitochondrial Mass, and Modulates Mitochondrial Quality Control Signaling in the Rat Heart. Biomolecules 8:
Chimienti, Guglielmina; Picca, Anna; Sirago, Giuseppe et al. (2018) Increased TFAM binding to mtDNA damage hot spots is associated with mtDNA loss in aged rat heart. Free Radic Biol Med 124:447-453
Picca, Anna; Pesce, Vito; Sirago, Giuseppe et al. (2016) ""What makes some rats live so long?"" The mitochondrial contribution to longevity through balance of mitochondrial dynamics and mtDNA content. Exp Gerontol 85:33-40
Picca, Anna; Pesce, Vito; Fracasso, Flavio et al. (2014) A comparison among the tissue-specific effects of aging and calorie restriction on TFAM amount and TFAM-binding activity to mtDNA in rat. Biochim Biophys Acta 1840:2184-91
Picca, Anna; Fracasso, Flavio; Pesce, Vito et al. (2013) Age- and calorie restriction-related changes in rat brain mitochondrial DNA and TFAM binding. Age (Dordr) 35:1607-20
Joseph, Anna-Maria; Adhihetty, Peter J; Wawrzyniak, Nicholas R et al. (2013) Dysregulation of mitochondrial quality control processes contribute to sarcopenia in a mouse model of premature aging. PLoS One 8:e69327
Fletcher, Quinn E; Selman, Colin; Boutin, Stan et al. (2013) Oxidative damage increases with reproductive energy expenditure and is reduced by food-supplementation. Evolution 67:1527-36
Picca, Anna; Pesce, Vito; Fracasso, Flavio et al. (2013) Aging and calorie restriction oppositely affect mitochondrial biogenesis through TFAM binding at both origins of mitochondrial DNA replication in rat liver. PLoS One 8:e74644
Aris, John P; Alvers, Ashley L; Ferraiuolo, Roy A et al. (2013) Autophagy and leucine promote chronological longevity and respiration proficiency during calorie restriction in yeast. Exp Gerontol 48:1107-19
Joseph, Anna-Maria; Malamo, Angelina G; Silvestre, Jason et al. (2013) Short-term caloric restriction, resveratrol, or combined treatment regimens initiated in late-life alter mitochondrial protein expression profiles in a fiber-type specific manner in aged animals. Exp Gerontol 48:858-68

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