MEF2A and endothelial dysfunction: For instance, silencing of circular zinc finger protein 609 (circZNF609) improves the endothelial dysfunction associated with high glucose and hypoxia stress, at least in part, by sponging miR-615-5p activity, leading to increased Myocyte Enhancer Factor 2A (MEF2A) expression [21], and several circRNA–miRNA–mRNA networks associated with oxidized low-density lipoprotein endothelial injury and atherogenesis have been reported [22].