Background Ventricular tachycardia (VT) and ventricular fibrillation are the most causes of early death in patients with myocardial infarction (MI). This study was aimed to explore whether LRP6 and its upstream genes circRNA1615 and miR-152-3p modulated the phosphorylation of Connexin-43 (Cx43) via Gαs in VT of MI. Method we constructed the hypoxia cardiomyocyte model and AMI mice, and explored the modulation relationship of LRP6 and its upstream genes circRNA1615 and miR-152-3p. In addition, the immunoblot analysis with monoclonal and polyclonal antibodies were used to detect whether LRP6 and Cx43 were phosphorylated, further investigated that the LRP6 regulated the phosphorylation of its downstream target Cx43 via G-protein alpha subunit Gαs by using cell transfection, FISH assay, HE staining, RTqPCR, and Western blot techniques. Result LRP6 mRNA expression was significantly reduced in AMI group compared with the control group. Hypoxia could inhibit the protein and phosphorylation levels of LRP6 and Cx43. The expression of circRNA1615 in AMI mice was significantly decreased, but overexpression of circRNA1615 significantly reversed the inhibitory effect of AMI. Also overexpression of circRNA1615 could weaken the effect of miR-152-3p mimic, and the miR-152-3p mimic increased the hypoxia injury of LRP6 and Cx43, further LRP6 interference fragments could aggravate hypoxia injury of Cx43. The overexpression of LRP6 could significantly increase the protein level and phosphorylation level of Cx43, but the interference with LRP6 showed the opposite trend. Noticeably, the interference with Gαs weakened the protein and phosphorylation levels of Cx43, however, the interference with LRP6 and Gαs further inhibited the protein and phosphorylation levels of Cx43. Finally, the transcriptions of circRNA1615 and LRP6 were inhibited in AMI, but the transcription of miR-152-3p was promoted, and the overexpression of circRNA1615 could weaken the damage effect and VT of AMI. Conclusion LRP6 and its upstream genes circRNA1615 and miR-152-3p modulated the phosphorylation of Cx43 via Gαs in VT of MI.

Background: Previous studies had shown that mRNA, miRNA and lncRNA were associated with cardiovascular diseases. The study was aimed to explore the differential expressions of mRNA, lncRNA and miRNA between coronary artery disease (CAD)and healthy control, and their interaction in CAD. Methods: We investigated the differential expression of ceRNA between CAD and healthy control through data collected from Gene Expression Omnibus (GEO) microarrays. Furthermore, we investigated the biological function of these differential expressions of ceRNAs by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Protein-protein interaction (PPI) network was created to identify the hub genes. Biosystems and literature search were performed for signaling pathways and their function of the included differential expression ceRNAs. Results: A total of 456 miRNA expression profiles, 16,325 mRNA expression profiles, and 2,869 lncRNA expression profiles were obtained. Eleven Go and KEGG pathways (count ≥9), top 15 of PPI network node connectivity rank, and top 15 of ceRNA network node degree centrality rank were achieved at the statistical significance level (P<0.05). We further identified that several differential expressions of ceRNAs and their signaling pathways were associated with CAD through biosystems and literature search. Conclusions: Based on eleven Go and KEGG pathways, top 15 of PPI network node connectivity rank, and top 15 of ceRNA network node degree centrality rank in CAD population, our findings would contribute to further exploration for the molecular mechanism of CAD.