Alterations In Cold-inducible RNA-binding Protein And KCND3 Expression In Patients With Atrial Fibrillation

Research backgroundAtrial fibrillation is the commonest sustained arrhythmia encountered in clinical practice. Its prevalence increases with age. Atrial fibrillation affects normal systolic and diastolic function, causing a series of clinical performance. It is worth noting that atrial fibrillation is strongly associated with hypertension, coronary heart disease, valvular heart disease and other diseases. As huge numbers of our population, atrial fibrillation not only endangers the health of many citizens, but also causes a tremendous socio-economic burden. The pathogenesis of atrial fibrillation is not fully clear. Potassium voltage-gated channel subfamily D member 3 also known as Kv4.3 is a protein that in humans is encoded by the KCND3 gene, playing an important role in the pathogenesis of Brugada syndrome,and its relationship with atrial fibrillation has gradually attracted people’s attention.In recent years, studies have shown that cold-inducible RNA binding protein affects cardiac electrophysiology through adjusting KCND3 expression, thus showing its position on the treatment of arrhythmia.ObjectiveOur goal was to study the influence of atrial fibrillation on expression of KCND3 and CIRP and to explore the possible mechanisms.Method1. We assessed the clinical characteristics of the patients before surgery.Patients’ history and previous electrocardiograms were used to establish type and duration of AF. In addition, medication use and exercise tolerance(according to the New York Heart Association(NYHA) classification) were determined.Echocardiography data were obtained before surgery.2. Right atrial appendages were obtained from 3 patients with AF. The AF patients were matched with 5 clinically stable patients in sinus rhythm.Immediately after excision, the right atrial appendages were snap-frozen in liquid nitrogen and stored at-80℃.3. Real-Time PCR was used to detect the level of m RNA of KCND3 and CIRP.4. Immunohistochemistry was used to detect protein of KCND3 and CIRP.5. The statistical analysis.Results1.The level of KCND3 m RNA decreased significantly when compared with control group(p<0.05). The level of CIRP m RNA was increased when compared with control group(p<0.05).2. Immuno- histochemistry:CIRP protein had a large expression in the myocardial cells, some KCND3 protein expressed in myocardial cells; The level of KCND3 protein decreased significantly when compared with control group(p<0.05). The level of CIRP protein was increased when compared with control group(p<0.05).3. Correlation analysis:The m RNA and protein expression of KCND3 is negative related to CIRP.ConclusionOur study showed that AF is accompanied by reductions in m RNA and protein levels of Ito potassium channels and augment in m RNA and protein levels of CIRP. There may be some link between them and provide new method for the prevention and treatment of atrial fibrillation.