The heart has the highest concentration of mitochondrial oxidative phosphorylation (OXPHOS) enzymes of any organ in the body. It has been proposed that in many forms of heart failure, the myocardial cells enter a chronic energy deficient state which ultimately leads to dysfunction and death. The cardiac myocytes respond to this low energy state, by induction of a number of fetal contractile and energy system isoforms which presumably are more optimal for reduced mitochondrial energy production. We have cloned and sequenced the human mitochondrial ATP synthase beta subunit (ATPsyn beta) and heart-skeletal muscle adenine nucleotide translocator (ANT1) genes. Both are expressed at very high levels in heart and skeletal muscle, but in other tissues ATPsyn beta is expressed at low levels and the ANT1 is replaced by two other isoforms, ANT2 and ANT3. With these genes we will explore the energy deficiency hypothesis of heart failure by: (1) defining the molecular basis for the high ex- pression of OXPHOS genes in heart and muscle, (2) determining the changes that occur in OXPHOS gene expression in the failing heart and (3) demonstrating that direct genetic and biochemical inhibition of heart OXPHOS can cause cardiomyopathy. To define the molecular basis of heart-muscle expression of OXPHOS genes, we have prepared promoter-reporter gene constructs for both genes and have identified a shared heart-muscle control element, the OXBOX. Other muscle-specific elements are being mapped and the associated trans-acting factors sought. To identify energetic changes associated with failing hearts, we will examine the expression of these genes in both spontaneous and hereditary forms of heart disease for alteration in ANT isoform expression, changes in mRNA levels and variation in implicated transcription factors. To demonstrate that OXPHOS defects can cause heart failure, we will screen idiopathic cardiomyopathy hearts for possible mtDNA deletions, and determine if the ANT autoantibodies which are associated with myocarditis and dilated cardiomyopathy are specific for ANT1 and capable of perturbing cardiac myocyte energy metabolism and of inducing cardiomyopathy.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL045572-02
Application #
3364612
Study Section
Mammalian Genetics Study Section (MGN)
Project Start
1991-04-01
Project End
1995-03-31
Budget Start
1992-04-01
Budget End
1993-03-31
Support Year
2
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Emory University
Department
Type
Schools of Medicine
DUNS #
042250712
City
Atlanta
State
GA
Country
United States
Zip Code
30322
Lell, Jeffrey T; Sukernik, Rem I; Starikovskaya, Yelena B et al. (2002) The dual origin and Siberian affinities of Native American Y chromosomes. Am J Hum Genet 70:192-206
Wallace, Douglas C (2002) Animal models for mitochondrial disease. Methods Mol Biol 197:3-54
Biousse, Valerie; Pardue, Machelle T; Wallace, Douglas C et al. (2002) The eyes of mito-mouse: mouse models of mitochondrial disease. J Neuroophthalmol 22:279-85
Schurr, Theodore G; Wallace, Douglas C (2002) Mitochondrial DNA diversity in Southeast Asian populations. Hum Biol 74:431-52
Wallace, D C (2001) Mouse models for mitochondrial disease. Am J Med Genet 106:71-93
Sandbach, J M; Coscun, P E; Grossniklaus, H E et al. (2001) Ocular pathology in mitochondrial superoxide dismutase (Sod2)-deficient mice. Invest Ophthalmol Vis Sci 42:2173-8
Melov, S; Doctrow, S R; Schneider, J A et al. (2001) Lifespan extension and rescue of spongiform encephalopathy in superoxide dismutase 2 nullizygous mice treated with superoxide dismutase-catalase mimetics. J Neurosci 21:8348-53
Sligh, J E; Levy, S E; Waymire, K G et al. (2000) Maternal germ-line transmission of mutant mtDNAs from embryonic stem cell-derived chimeric mice. Proc Natl Acad Sci U S A 97:14461-6
Wallace, D C (2000) Mitochondrial defects in cardiomyopathy and neuromuscular disease. Am Heart J 139:S70-85
McMahon, F J; Chen, Y S; Patel, S et al. (2000) Mitochondrial DNA sequence diversity in bipolar affective disorder. Am J Psychiatry 157:1058-64

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