Mirna-Mediated Mechanisms of Cardiac Protection in Ischemic and Remote Ischemic Preconditioning - A Qualitative Systematic Review.

BACKGROUND: Ischemic preconditioning (IPC) and remote ischemic preconditioning (RIPC) protect myocardial tissue against subsequent ischemia and reperfusion injury (IRI) and have a high potential to improve patient outcome. The mediators and mechanisms of protection through IPC and RIPC remain largely unknown, but micro-RNAs (miRNAs) are promising candidates.

METHODS: Systematic review of Medline and Embase databases for biomedical scientific literature.

RESULTS: 26 relevant publications (21 full-text original articles and 5 conference abstracts) were identified, 8 describing cell culture experiments, 14 animal experiments and 4 randomised clinical trials in humans. Most commonly reported miRNAs with differential expression between preconditioned and control groups include miR-1, miR-21 and miR-144. Experimental designs and procedures differ widely, thereby limiting the potential to compare results between studies. Two of the four RCTs did not find any differentially expressed miRNAs.

CONCLUSIONS: Results from RCTs should feed back into basic research and focused studies confirming or rejecting hypotheses generated by these RCTs are needed.