In Vivo Investigation of the Role of MicroRNAs in Anaesthetic-Induced Cardioprotection Against Ischemia/Reperfusion Damage: A Study Protocol

Background: Designing studies to increase knowledge of the beneficial effects of volatile halogenated anaesthetics(VHAs) is critical to understand the mechanisms activated by myocardial conditioning during ischaemia-reperfusion(I/R) injury. Our research group has identified specific enzymes associated with the SAFE/RISK signalling pathways involved in halogen-induced cardioprotection and has observed a direct correlation between the expression of specific microRNA(miRNAs) and the cardioprotective effect conferred by VHA. Objective: This protocol study has been designed to increase knowledge regarding the cardioprotective effects generated by induced cardioprotective miRNAs after exposure to halogenated drugs without subjecting the patient to additional surgical procedures. Methods: The experimental design that is proposed will be performed with isogenic Wistar rats, all subjected to an I/R procedure. The animals will be randomly divided into two groups: the Donor group and the Recipient group. Half of the rats included in both groups will be exposed to sevoflurane (S), a hypnotic drug, during the I/R procedure, and the other half will be injected with propofol (P), a hypnotic. EVs will be isolated from plasma samples extracted from rats in the Donor group 24 h after the I/R procedure. In vitro EV characterisation will be performed by conducting an ultramorphological analysis, identifying the EV immunophenotype, and quantifying miRNAs. Cardiac function will be assessed by transthoracic echocardiography, histological, and immunohistochemical analyses. Results: The results derived from studies conducted according to this experimental design will support its validation as a preclinical study by regulatory authorities for approval and will serve to design a Phase I clinical trial. Conclusions: The proposed scientific rationale of applying this proposed experimental design will enable the generation of knowledge ‘from the bench to the bedside’ regarding miRNAs with cardioprotective properties induced by exposure to halogenated agents, which could be considered as biomarkers of cardioprotection. Furthermore, biomarker administration could reduce cardiac damage in patients undergoing additional cardiac surgery.