Introduction: Elevated markers of endothelial dysfunction and inflammation indicate worse endothelial function in the aging haemophilia population. MicroRNAs (miRNAs) regulate gene expression post-transcriptionally. Several miRNAs have been shown to be involved in the process of endothelial dysfunction and atherosclerosis. Aim: The aim of this study was to determine the underlying molecular pathways of endothelial dysfunction and inflammation in haemophilia patients. Methods: A total of 25 patients with severe or moderate haemophilia A (20 patients) or B (5 patients), 14 controls and 18 patients with coronary artery disease (CAD) after myocardial infarction were included in this study. Expression of miRNA-126, -155, -222, -1, -let7a, -21 and -197 were analysed using a real time polymerase chain reaction. Network-based visualisation and analysis of the miRNA-target interactions were performed using the MicroRNA ENrichment TURned NETwork (MIENTURNET).Results: Expression of miRNA-126 (p < .05) and miRNA-let7a (p < .05) were significantly higher in CAD patients compared to haemophilia patients and controls.MiRNA-21 (p < .05) was significantly elevated in CAD patients compared to controls.MiRNA-155 (p < .05), miRNA-1 (p < .05) and miRNA-197 (p < .05) were significantly higher expressed in CAD and haemophilia patients compared to controls and showed a strong correlation with increased levels of interleukin-6 (IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1). The network analysis revealed interactions in the cytokine signalling, focal adhesion and VEGFA-VEGFR2 pathway (Vascular endothelial growth factor, -receptor).
Conclusion:This study characterises miRNA expression in haemophilia patients in comparison to CAD patients and healthy controls. The results imply comparable biological processes in CAD and haemophilia patients.