The Difference Of MicroRNA-1,133 Expression In Myocardium Of Model Dogs And Patients With Atrial Fibrillafion

Objective:MicroRNAs(miRNAs) are small RNA molecules of approximately 20-24 nucleotides in length. They were highly conserved、non-encoding and regulate gene expression in post-transcriptional level. Recent studies have found that miRNA-1 and miRNA-133 are abundantly express in the heart. They regulate every pathophysiological process of the heart, they induce or inhibit cardiac myocardial hypertrophy, apply to fibroblasts, regulate cardiac fibrosis, and participate in the cardiac ion channels electrophysiological process. The study include:(1)To compare the difference of microRNA-1 and microRNA-133 expression in myocardium of dogs with sinus rhythm(SR) and atrial fibrillafion(AF). (2)To compare the difference of microRNA-1 and microRNA-133 expression in myocardium of patients with SR and AF.Methods:(1)20 dogs according to whether atrial pacing into two groups.10 dogs with SR and 10dogs with persistent AF induced by rapid atrial pacing which is line of atrial pacing 8 weeks(600 times/min). The echocardiography was used for determining the cardiac structure size. And quantitative real-time polymerase chain reaction(Real-time PCR) was applied to assess the difference of expressions of microRNA-1 and microRNA-133. (2) the right atrium samples of 40 patients who must have coronary bypass surgery were collected. The patients must under the age of 65.20 with SR and 20 with persistent AF. Also use real-time PCR to campare the difference of expressions of microRNA-1 and microRNA-133.Results:(1)Compared dog groups the expressions of microRNAs-1 and-133 showed obvious downregulation tendency in AF group than in SR. (2)And compared patient group the expressions of microRNAs-1 and-133 also showed downregulation tendency in AF group than in SR.Conclusion:Expressions of microRNAs-1 and-133 in myocardium of model dogs and patients with AF showed downregulation tendency. Point out microRNA-1 and microRNA-133 may be responsible for the occurrence and maintaining of AF. The findings will provide new ideas for the development of new、safe and effective drugs in prevention and treatment for AF in the future.