Patented biomarker for cardiac injury. 

Patented biomarker for cardiac injury. 

Identification of cMyC as a Candidate Biomarker of Myocardial Infarction by Proteomics Analysis

Study

Discovery of cMyC in the coronary effluent after myocardial infarction.

Acute myocardial infarction (AMI) is a common cause of death for which effective treatments are available provided that diagnosis is rapid.

The current diagnostic gold standards are circulating cardiac troponins I and T. However, their slow release delays diagnosis, and their persistence limits their utility in the identification of reinfarction.

The aim was to identify candidate biomarkers of AMI. Isolated mouse hearts were perfused with oxygenated protein-free buffer, and coronary effluent was collected after ischemia or during matched normoxic perfusion.

Effluents were analyzed using proteomics approaches based on one- or two-dimensional initial separation. Of the 459 proteins identified after ischemia with one-dimensional separation, 320 were not detected in the control coronary effluent. Among these were all classic existing biomarkers of AMI. We also identified the cardiac isoform of myosin-binding protein C in its full-length form and as a 40-kDa degradation product.

This protein was not detected in the other murine organs examined, increased markedly with even trivial myocardial infarction, and could be detected in the plasma after myocardial infarction in vivo, a profile compatible with a biomarker of AMI. Two-dimensional fluorescence DIGE of ischemic and control coronary effluents identified more than 200 asymmetric spots verified by swapping dyes.

Once again existing biomarkers of injury were confirmed as well as posttranslational modifications of antioxidant proteins such as peroxiredoxins.

Perfusing hearts with protein-free buffers provides a platform of graded ischemic injury that allows detailed analysis of protein release and identification of candidate cardiac biomarkers like myosin-binding protein C (cMyC).

Additional documents

Supplementary material 1: Molecular & Cellular Proteomics

Supplementary material 2: Molecular & Cellular Proteomics

Protein release after 5 min of ischemia (identified on the 1D gel) is plotted as -fold change (unique peptide in ischemia/unique peptide in control ratio) on the ordinate against absolute abundance on the abscissa. Abundance is estimated by the obtained spectral count normalized to the molecular weight of the individual protein. The known biomarkers of myocardial infarction are highlighted in red, and proteins in the coronary effluent with a -fold change greater than 5 are numbered and listed in Table IV.