Effect of radiofrequency ablation on miRNA expression in coronary sinus blood of patients with atrial fibrillation

Objective To investigate the effect of radiofrequency ablation (RFA) on miRNA expression in coronary sinus blood (CSB) of patients with atrial fibrillation (AF), especially after the termination of AF by RFA. And try to identify the possible miRNAs which can play real regulatory role in AF, so that to find the pathogenesis of AF and possible miRNA targets for intervention. Methods Thirty AF patients (paroxysmal, persistent and permanent AF, 10 each) were enrolled, alongside of 10 healthy subjects as controls. Peripheral blood (PB) samples were obtained before and 3 months after RFA, respectively. The total RNA was extracted and hybridized with the microRNA chips (microRNA v18.0), and the differential expressions of miRNA and clustering analysis in whole genome were performed with Volcano Plot and tMEV software respectively, and validated by Real-time PCR. The target gene of miRNAs was analyzed by retrieving the mirbase, miranda and targetscan databases. The important miRNAs were undergone with dual luciferase binding experiment to analyze and validate target genes. Results Comparing the CSB with PB of patient-self before RFA, 142 miRNAs expressed differently, of which 6 up-regulated and 8 down-regulated significantly (P