The Expression And Clinical Implication Of Plasma MiRNA-328in Patients With Atrial Fibrillation

BackgroudAtrial fibrillation (AF) is one of the most common cardiac arrhythmia,and its prevalence is about1%.With the increasing of the risk factors of AF,such as aging,hypertension,diabetes,obesity and heart failure,the prevalence is also significantly increased,which is moer than6%in people over the age of80. AF can lead to potentially serious cardiovascular complications such as heart failure and stroke,it has always been the focus of attention and research.Although the pathological mechanism is not fully understood,now the "multiwavelet reentrant "hypothesis,ectopic excited foci trigger and theregulation of the autonomic nervous are the mechanisms widely accepted.Trigger factors and the maintain of reentrant and the change of matrix of electrical activity coupled with anatomical structures reconstruction,contraction remodeling and electrical remodeling which one can result in and from another are the characteristic changes in AF. The mechanism of the interactions among various remodeling,and the effects of miRNAs in various remodeling are still unclear.MicroRNA (miR,miRNA) first reported in1993by Lee,was a class of transcription generated by the non-coding region,with the length of about19～25nt small molecules single-stranded RNA,which could combine with the target mRNA molecules,leading to degradation or translation inhibition.Through the post-transcription regulation,microRNA involved in a variety of pathophysiological processes. There were stable and tissue-specific microRNAs in plasma. Since2008miRNAs have served as a biomarkers for muscle damage,cancer,inflammation, cardiovascular disease and other areas for diagnosis. Studies shown that,miRNA-328was significantly higher in the dog atrial fibrillation model and atrial tissue of patients with atrial fibrillation.ObjectiveIn this study,real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of plasma miRNA-328in patients with AF,and to analyze the relationships with the risk factors of AF,and to explore its significance in AF pathophysiology,and its possible role in the biological characteristics of AF. We hope to provide new ideas for clinical diagnosis and treatment for AF.Methods(1) Objective groups:AF group contains fifty-eight patients with AF, including17cases with paroxysmal AF,21patients with persistent AF, and20cases with permanent AF. And15healthy volunteers were inrolled as control group.(2) Plasma miRNA-328was detected with quantitative real-time polymerase chain reaction (qRT-PCR) analysis.(3) General clinical data and related biochemical parameters of the two groups were collected.The correlation between plasma miRNA-328and AF risk factors were analyzed.(4) SPSS17.0statistical software was applied for the data statistics.The experimental data was expressed with the mean±standard deviation,Two Independent Sample t-test was employed to test the difference between two groups. A3-way Single factor analysis of variance (ANOVA) was applied to analyze the difference among the patients with AF of different type,and LSD-t method for comparison between groups,and multiple independent samples rank sum test (H test) for skewed or unequal variances among samples. A chi-square test was used for count data comparison. The pair-wise correlations were analyzed by Pearson correlation analysis or partial correlation analysis.A a value of0.05was considered statistically significant.Results(1) Compared with the control group(1.00±0.00),the expression level of plasma miRNA-328in AF group (7.72±9.32)was significantly increased (P<0.05).(2) Among paroxysmal AF,persistent AF and permanent AF,the difference of expression levels of plasma miRNA-328(1.98±0.81vs6.57±5.82vs13.47±12.29)were statistically significant (P<0.05),and the longer extension of the AF duration,the higher the expression of plasma miRNA-328.(3) In the experimental group,the level of plasma miRNA-328was positively correlated with left atrial diameter,and the correlation coefficient was0.310(P<0.05).Conclusion(1) Compared with the control group,miRNA-328expression level increased in plasma in patients with atrial fibrillation,which may act as a new quantitative index biomarker for the clinical diagnosis and biological classification evaluation of atrial fibrillation.(2) MiRNA-328expression is positively related to left atrial enlargement,which may involved in atrial remodeling.