Preliminary Screening Of New Warning Biomarkers For Acute Myocardial Injury

The cardiac injury can be caused by many factors, for example, the coronary atherosclerosis can cause the ischemia injury of the heart; the heart open surgery under cardiopumanery bypass, the coronary artery bypass surgery will cause the cardiac ischemia referfusion injury. The warning biomarkers play an important role in the evaluation of cardiac injury. The idea biomarkers for cardiac injury should be highly sensitive and tissue specific; also it must appear at an early stage of cardiac injury and persist for a long time; it must be convenient and cheap for detection. Through the combinational use of the bioinformatics, whole animal model, and serological immunology methods, we hope to find new warning biomarkers of cardiac injury with the aim to accelerate the early diagnosis, early intervention for heart injury. Also we want to use the new biomarkers to accurately evaluate the effectiveness of measures and medicines in cardiac protection.Firstly we selected the proper database from the Gene Expression Omnibus, then identified the highly and uniquely expressed cardiac genes from these database via setting different expression/statistical parameter standard. By comparison of the different genes selected from two different databases, we found a group of genes which exists in both databases. Sixteen genes were finally identified from them. By analysing the protein expression and their serological abundance, four candidate genes were picked up and further analysis were performed to detect its expression in the serum, i.e., mitochondrial aconitase 2 (AC02), the thrombospondin receptor CD36, S100 calcium binding protein Al(S100A1), angiotensin I converting enzyme peptidyl-dipeptidase A2(ACE2). A cardiac ischemia-refurfusion injury was induced by ligation and then release of the left coronary anterior descending artery, and the blood were sampled from the external jugular vein at 2h,4h,6h,24h after reperfusion. The serum levels above four proteins were detected at different time points. Some proteins were further detected in the patients with acute coronary syndrome (ACS).The results are as follows:1. at 4h, 6h,24h after reperfusion, the serum levels of ACE2, ACO2 were obviously decreased as compared with those before operation (p<0.05). The serum level of CD36 was increased at 4h and arrived at its peak at 24h after reperfusion (p<0.05).2:The serological level of CD36 was significantly increased in the patients with ACS as compaired with the normal controls (p<0.05).Further studies are still needed to prove whether these four molecules can be used as the new warning biomarkers of cardiac injury.