Abstract
Aim To verify the cardiac hypertrophical role of circ_0004641 and its potential mechanism by targeting miR1192-TRIM25/TRIM41 axis.
Methods Mice model was constructed by abdominal aortic coarctation (AAC) surgery and cell model was established from isolated neonatal mouse ventricular cardiomyocytes (NMVCs) by co-cultured with angiotensin II (Ang II). Differential expressed circRNAs were identified by Next-generation sequencing and target miRNAs and downstream mRNAs were predicted by bioinformational analysis. RT-qPCR and Western Blot were applied to validate myocardial-associated molecules on transcriptional and translational levels respectively. By transfecting siRNAs or co-culturing with mimics, expression of regulating-molecules was detected respectively. Dual luciferase reporter assay was performed to identify the interaction between circular RNA and miRNA.
Results A total of 5 up-regulation and 25 down-regulation circRNAs were detected on hypertrophical myocardium by Next-generation sequencing. Among them, circ_0004641 was significantly increased both in in vivo and in vitro as ANP and β-MHC accumulated, while downstream target miRNA-1192 decreased and target mRNA (TRIM25/TRIM41) increased dramatically. Knock-down of circ_0004641 by transfecting siRNA shows a reverse effect on cardiac hypertrophy, along with contrary expressive trend of miR-1192 and TRIM25/TRIM41.Dual luciferase reporter assay identified the sponge-like interaction between circ_0004641 and miR-1192. By co-culturing NMVCs with miR-1192 mimics, its targets TRIM25/TRIM41 showed significant decrease. Moreover, NF-κB signaling pathway were identified to correlated by circ_0004641/miRNA-1192 axis as P65 protein present similar expressive trend with circ_0004641.
Conclusion circ_0004641 may exert a stimulative role in cardiac hypertrophy by regulating miR-1192-TRIM25/TRIM41 axis and NF/κB p65 pathway is the underlying downstream pathway.