MiR-16, as a potential NF-κB-related miRNA, exerts anti-inflammatory effects on LPS-induced myocarditis via mediating CD40 expression: A preliminary study.

The purpose of this study was to investigate the biological effect of miR-16 on myocarditis and the underlying molecular mechanism. H9c2 cells were treated with 10 µg/mL lipopolysaccharide (LPS) for 12 hours to form a myocarditis injury model. We observed that LPS treatment distinctly decreased the level of miR-16 in H9c2 cells. Upregulation of miR-16 increased cell proliferation and reduced cell apoptosis. Then, CD40 was predicted and verified as a target gene of miR-16 by TargetScan and luciferase reporter assay, respectively. Furthermore, the messenger RNA and protein expression of CD40 are negatively regulated by miR-16. The relative expression of inflammatory factors was dramatically decreased by the miR-16 mimic. Cells cotransfected with miR-16 mimic and si-CD40 could significantly abolish the injury of cardiomyocytes caused by myocarditis. Our study illustrated that the upregulation of miR-16 has a protective effect on LPS-damaged H9c2 cells, which may be achieved by regulating CD40 and the nuclear factor kappa B pathway.