Can microRNAs be Biomarkers or Targets for Therapy of Ischemic Coronary Artery Disease in Metabolic Syndrome?

Background: Due to their exceptional stability in the circulation, microRNAs (miRs) are being identified as promising biomarkers. On the other hand, their propensity to regulate networks of functionally closely related genes and relative ease of delivery makes them attractive targets for therapy. However, neither application is without challenges, especially as it applies to ischemic coronary artery disease (CAD). Objective: This review will: 1) describe miRs which have been most consistently found to be associated with the most common manifestations of CAD, including atherosclerosis, angina pectoris, myocardial infarction and myocardial reperfusion through arteriogenesis, 2) emphasize those miRs which are also altered in metabolic syndrome and its component pathologies, 3) discuss challenges which currently prevent clinical application related to inconsistencies between findings in cell culture, animal models and among human studies, as well as technical challenges, and 4) offer some suggestions towards resolutions of these discrepancies. Conclusion: While miRs can be used as reliable biomarkers for myocardial infarction, their use as biomarkers for other forms of ischemic CAD, as well as therapy for CAD await further investigation.