Proteomic analysis of cardiac ventricles: baso-apical differences

Area of Science:

• Cardiology
• Proteomics
• Molecular Biology

Background:

• The heart displays significant heterogeneity, with different regions responding uniquely to pathological stimuli.
• Understanding regional molecular differences is crucial for studying cardiac pathologies.
• Baso-apical heterogeneity, alongside known left/right ventricular and transmural differences, warrants investigation.

Purpose of the Study:

• To compare the proteomes of the apical and basal regions of the rat left ventricle (LV) and right ventricle (RV).
• To identify specific proteins with differing concentrations between these cardiac regions.
• To elucidate the functional implications of observed proteomic differences.

Main Methods:

• Proteomic analysis using two-dimensional electrophoresis.
• Comparison of protein expression profiles between apical and basal segments of both LV and RV in rats.

Main Results:

• Significant baso-apical differences in protein concentrations were identified in both LV and RV.
• In the LV, five proteins, including mitochondrial enzymes (myofibrillar creatine kinase M-type, L-lactate dehydrogenase, dihydrolipoamide dehydrogenase), myosin light chain 3, and HSP60, were more concentrated apically.
• In the RV, two mitochondrial proteins (creatine kinase S-type, proton pumping NADH:ubiquinone oxidoreductase) showed higher apical concentrations.

Conclusions:

• The rat heart exhibits distinct baso-apical proteomic profiles in both ventricles.
• These differences are more pronounced in the LV, correlating with its higher workload.
• Elevated protein concentrations in apical regions suggest higher energetic demand and contractile activity in these segments.