Aged patients with atrial fibrillation exhibited significantly higher HCN2 and HCN4 channel expression and lower miR-1 and miR-133 expression compared to aged patients with sinus rhythm.
Cross-Sectional (n=60)
No
Age-associated upregulation of HCN channels and downregulation of miR-1 and miR-133 in the right atrium may contribute to the electrophysiological changes that trigger age-associated atrial fibrillation.
Tasa de eventos absoluta: 1% vs 0.49%
valor p: p=<0.05
Hyperpolarization-activated cyclic nucleotide-gated (HCN) cation channels mediate pacemaker currents in the atrium. The microRNA (miR) families miR-1 and miR-133 regulate the expression of multiple genes involved in myocardial function, including HCN channels. It was hypothesized that age‑dependent changes in HCN2, HCN4, miR‑1 and miR‑133 expression may contribute to age‑associated atrial fibrillation, and therefore the correlation between expression levels, among adult (≤65 years) and aged patients (≥65 years), and sinus rhythm was determined. Right atrial appendage samples were collected from 60 patients undergoing coronary artery bypass grafting. Reverse transcription-quantitative polymerase chain reaction (PCR) and western blot analyses were performed in order to determine target RNA and protein expression levels. Compared with aged patients with sinus rhythm, aged patients with atrial fibrillation exhibited significantly higher HCN2 and HCN4 channel mRNA and protein expression levels (P<0.05), but significantly lower expression levels of miR‑1 and miR‑133 (P<0.05). In addition, aged patients with sinus rhythm exhibited significantly higher expression levels of HCN2 and HCN4 channel mRNA and protein (P<0.05), but significantly lower expression levels of miR‑1 and ‑133 (P<0.05), compared with those of adult patients with sinus rhythm. Expression levels of HCN2 and HCN4 increased with age, and a greater increase was identified in patients with age‑associated atrial fibrillation compared with that in those with aged sinus rhythm. These electrophysiological changes may contribute to the induction of ectopic premature beats that trigger atrial fibrillation.
Li et al. (Mon,) conducted a cross-sectional in Age-associated atrial fibrillation (n=60). Aged atrial fibrillation (Exposure) vs. Aged sinus rhythm and adult sinus rhythm was evaluated on HCN2 mRNA expression (p=<0.05). Aged patients with atrial fibrillation exhibited significantly higher HCN2 and HCN4 channel expression and lower miR-1 and miR-133 expression compared to aged patients with sinus rhythm.