Post-transcriptional regulation of cardiac sodium channel gene SCN5A expression and function by miR-192-5p

Abstract

The SCN5A gene encodes cardiac sodium channel Nav1.5 and causes lethal ventricular arrhythmias/sudden death and atrial fibrillation (AF) when mutated. MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression, and involved in the pathogenesis of many diseases. However, little is known about the regulation of SCN5A by miRNAs. Here we reveal a novel post-transcriptional regulatory mechanism for expression and function of SCN5A/Nav1.5 via miR-192-5p. Bioinformatic analysis revealed that the 3′-UTR of human and rhesus SCN5A, but not elephant, pig, rabbit, mouse, and rat SCN5A, contained a target binding site for miR-192-5p and dual luciferase reporter assays showed that the site was critical for down-regulation of human SCN5A. With Western blot assays and electrophysiological studies, we demonstrated that miR-192-5p significantly reduced expression of SCN5A and Nav1.5 as well as peak sodium current density INa generated by Nav1.5. Notably, in situ hybridization, immunohistochemistry and real-time qPCR analyses showed that miR-192-5p was up-regulated in tissue samples from AF patients, which was associated with down-regulation of SCN5A/Nav1.5. These results demonstrate an important post-transcriptional role of miR-192-5p in post-transcriptional regulation of Nav1.5, reveal a novel role of miR-192-5p in cardiac physiology and disease, and provide a new target for novel miRNA-based antiarrhythmic therapy for diseases with reduced INa.

Functional Role and Mechanism of microRNA-28b in Atrial Myocyte in a Persistent Atrial Fibrillation Rat Model

“…Caspase-3 activity in cardiomyocytes was measured by test kits (Sigma, USA), as reported previously [31]. …”

Combined Analysis of Human and Experimental Murine Samples Identified Novel Circulating MicroRNAs as Biomarkers for Atrial Fibrillation

“…Zhao et al showed that miR-192-5p was upregulated in the atrial tissue of AF patients, and miR-192-5p regulates the expression of the cardiac sodium channel gene, SCN5A. 32 Furthermore, miR-192 is known to reduce the expression of CAV1, which was found to have an association with AF by a genome-wide association study. 33, 34 The function of the 3 remaining miRNAs (miR-99a-5p, miR-214-3p, and miR-342-5p) has also been reported.…”

Down-regulation of microRNA-451a facilitates the activation and proliferation of CD4+ T cells by targeting Myc in patients with dilated cardiomyopathy

“…Jurkat T cells were cultured in 24-well plates at ϳ5 ϫ 10 4 cells/well and transfected with 200 ng of either pMIR-RE-PORT-Myc-3ЈUTR-WT or pMIR-REPORT-Myc-3ЈUTR-MUT and 100 nM miR-451a mimic or negative control NC-miRNA mimics, along with 20 ng of Renilla luciferase vector for normalization as described previously (42). The cell extracts were prepared 48 h after transfection, and the luciferase activity was measured using a Dual-Glo TM luciferase assay system (E2920, Promega).…”