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


METHODS
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.


METHODS
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
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.
Lopes
Rosana
R
Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA.
Solter
Philip F
PF
Sisson
D David
DD
Oyama
Mark A
MA
Prosek
Robert
R
D000818:Animals; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000662:veterinary*; D002311:Cardiomyopathy, Dilated / Q000378:metabolism / Q000662:veterinary*; D004283:Dog Diseases / Q000378:metabolism; D004285:Dogs; D045222:Electron Transport Chain Complex Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006352:Heart Ventricles / Q000378:metabolism; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism
D045222:Electron Transport Chain Complex Proteins