Correlation of mitochondrial protein expression in complexes I to V with natural and induced forms of canine idiopathic dilated cardiomyopathy

• Published in: American journal of veterinary research Vol. 67; no. 6; pp. 971 - 977
• Main Authors: Lopes, R, Solter, P.F, Sisson, D.D, Oyama, M.A, Prosek, R
• Format: Journal Article
• Language: English
• Published: United States 01-06-2006
• Subjects: adenosinetriphosphatase; Animals; Cardiac Pacing, Artificial - adverse effects; Cardiac Pacing, Artificial - veterinary; cardiomyopathy; Cardiomyopathy, Dilated - metabolism; Cardiomyopathy, Dilated - veterinary; cytochrome-c oxidase; Doberman Pinscher; dog diseases; Dog Diseases - metabolism; Dogs; Electron Transport Chain Complex Proteins - genetics; Electron Transport Chain Complex Proteins - metabolism; gene expression; Gene Expression Regulation; heart ventricle; Heart Ventricles - metabolism; Male; mitochondria; Mitochondria, Heart - metabolism; Myocardium - metabolism; NADH dehydrogenase (ubiquinone); succinate dehydrogenase (ubiquinone); ubiquinol-cytochrome-c reductase
• ISSN: 0002-9645; 1943-5681
• DOI: 10.2460/ajvr.67.6.971

Objective-To identify qualitative and quantitative differences in cardiac mitochondrial protein expression in complexes I to V between healthy dogs and dogs with natural or induced dilated cardiomyopathy (DCM). Sample Population-Left ventricle samples were obtained from 7 healthy dogs, 7 Doberman Pinschers with naturally occurring DCM, and 7 dogs with DCM induced by rapid right ventricular pacing. Procedures-Fresh and frozen mitochondrial fractions were isolated from the left ventricular free wall and analyzed by 2-dimensional electrophoresis. Protein spots that increased or decreased in density by 2-fold or greater between groups were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or quadrupole selecting, quadrupole collision cell, time-of-flight mass spectrometry. Results-A total of 22 altered mitochondrial proteins were identified in complexes I to V. Ten and 12 were found in complex I and complexes II to V, respectively. Five were mitochondrial encoded, and 17 were nuclear encoded. Most altered mitochondrial proteins in tissue specimens from dogs with naturally occurring DCM were associated with complexes I and V, whereas in tissue specimens from dogs subjected to rapid ventricular pacing, complexes I and IV were more affected. In the experimentally induced form of DCM, only nuclear-encoded subunits were changed in complex I. In both disease groups, the 22-kd subunit was downregulated. Conclusions and Clinical Relevance-Natural and induced forms of DCM resulted in altered mitochondrial protein expression in complexes I to V. However, subcellular differences between the experimental and naturally occurring forms of DCM may exist.