A proteomic approach to determine changes in proteins involved in the myocardial metabolism in left ventricles of spontaneously hypertensive rats

Abstract

Background: Different works have suggested that in the hypertrophied heart the energy metabolic pathway shifts to glycolysis. Our aim was to evaluate using proteomics the expression of proteins associated with different energetic metabolic pathways in hypertrophied left ventricles of spontaneously hypertensive rats (SHR).

Methods: 24-weeks-old SHR with stable hypertension and established left ventricle hypertrophy were used. Normotensive Wistar Kyoto rats were used as control. Proteins from left ventricles were analyzed by 2-dimensional electrophoresis and identified by comparison with a virtual rat heart proteomic map and mass spectrometry.

Results: Enoyl-CoA hydratase expression, an enzyme involved in fatty acid beta-oxidation, was reduced whereas the expression of other beta-oxidation enzymes, 3-ketoacyl-CoA thiolase and the mitochondrial precursor of acyl-CoA thioester hydrolase, was increased in the hypertrophied left ventricles. The expression of two enzymes involved in the first steps of glycolysis, fructose bisphosphate aldolase and triosephosphate isomerase, was reduced in the left ventricle of SHR. Pyruvate dehydrogenase expression, enzyme involved in glucose oxidation, was enhanced in the hypertrophied ventricles whereas proteins of the tricarboxylic acid cycle were not modified. Proteins involved in the mitochondrial oxidative phosphorylation were overexpressed whereas the alpha-subunit of the mitochondrial precursor of ATP synthase was downexpressed.

Conclusions: Several proteins involved in the main energy metabolic pathways were up and downexpressed. Moreover, our results seem to suggest that probably neither fatty acid beta-oxidation nor glycolysis are the only sources for energy in the hypertrophied left ventricle.