EGR-1 decoy ODNs inhibit vascular smooth muscle cell proliferation and neointimal hyperplasia of balloon-injured arteries in rat

AimsEarly growth response factor-1 (EGR-1) plays a master regulatory role in multiple cardiovascular pathological processes, such as atherosclerosis and restenosis. For investigating the possibility of using “decoy” strategy to prevent and cure vascular hyperplasia disease, we synthesized the double-stranded, cis-element, decoy oligodeoxynucleotides (ODNs) targeting EGR-1.Main methodsEGR-1 decoy ODNs were transfected into the balloon-injured arteria carotis of rat as well as primary cultures of vascular smooth muscle cells (VSMC). Changes in the thickness of the arterial intima were evaluated by hematoxylin-eosin (HE) staining. VSMC proliferation, DNA synthesis, cell cycle and apoptosis were observed via MTT assay, bromodeoxyuridine (BrdU) incorporation and flow cytometry (FCM). Changes in the expression of EGR-1, and cell cycle related genes, were detected by reverse transcriptase polymerase chain reaction (PT-PCR) and western blot.Key findingsAs a result of specific binding to EGR-1 protein, transfected EGR-1 decoy ODNs can reduce EGR-1 promoter affinity, hamper the transcriptional activation of EGR-1-dependent genes, block cell cycle progression of VSMCs, and inhibit neointimal hyperplasia.SignificanceThrough regulating the cell cycle progression and transcription of target gene, this new “decoy” strategy targeting EGR-1 provides further experimental evidence demonstrating the effectiveness of gene therapy in the treatment of restenosis following percutaneous coronary interventions.