Investigating microRNA expression levels associated with ischemia/reperfusion in coronart artery patients before and after coronary artery bypass graft surgery

Coronary artery disease is a cardiovascular disease characterized by obstruction of coronary vessels. Ischemic damage caused by the obstruction of coronary vessels allows the initiation of cellular and molecular events called cardiac remodeling. In many organisms, microRNAs that regulate gene expression post-transcriptionally have an important role in this process. It is reported that microRNAs can be evaluated as cardiac markers in the prevention of myocardial infarction and heart damage. In this study, we aimed to compare levels of microRNAs associated with ischemia / reperfusion (hsa-miR-21-5p, hsa-miR-199a-5p, hsa-miR-199b-5p, hsa-miR-320a-5p, hsa-miR-181a-5p) between control group and coronary artery patients undergoing bypass surgery. 46 patients and 48 healthy volunteers were included in this study. Blood samples were taken from these patients before surgery, 1 and 24 hours after surgery. MicroRNA levels in blood samples were detected by RT-PCR and calculated by delta (ΔCt) method. MicroRNA levels were significantly lower in the patients than the control group (p<0.001). When the miRNA levels were evaluated as time-dependent in the patients, there was a significant difference between 1st and 24th only in terms of miR-199a-5p levels that measured after surgery (p<0.044). In conclusion, miR-199a-5p can be associated with ischemia/reperfusion after coronary bypass surgery. Furthermore low levels of miR-199b-5p, miR-320a-5p and miR-181a-5p may play a role in activating inflammatory pathways involved in the pathogenesis of coronary artery disease. Further studies are needed to support these findings. Keywords: Bypass greft surgery, Coronary arter disease, Inflamation, Ischemia/Reperfusion, MicroRNA