Anti-inflammatory gene therapy for cardiovascular disease

Inflammation in the vascular wall is an essential hallmark during the development of atherosclerosis, for which major leukocytes infiltrated in the lesions are monocytes/macrophages. Therefore, monocyte chemoattractant protein-1 (MCP-1) and its primary receptor CC chemokine receptor 2 (CCR2) are feasible molecular targets for gene therapy to inhibit monocyte/macrophage-mediated inflammation in atherogenesis. A mutant MCP-1 that lacks N-terminal 7 amino acids (7ND) has been shown to heterodimerize with native MCP-1, bind to CCR2 and block MCP-1-mediated monocyte chemotaxis by a dominant-negative manner. Gene therapy using intramuscular transfection with plasmid DNA encoding 7ND showed inhibitory effects on atherosclerosis in hypercholesterolemic mice, and neointima formation after vascular injury in animal models. Bare metal stents for coronary intervention were coated with multiple thin layers of biocompatible polymer with 7ND plasmid. The 7ND gene-eluting stent inhibited macrophage infiltration surrounding stent struts and in-stent neointima formation in rabbit femoral arteries and cynomolgus monkey iliac arteries. Finally, the authors describe new application of 7ND plasmid encapsulated in polymer nanoparticle (NP) that functions as gene delivery system with unique in vivo kinetics. NP-mediated 7ND gene delivery inhibited MCP-1-induced chemotaxis of mouse peritoneal macrophage ex vivo, which may be applicable for the treatment of atherosclerotic cardiovascular disease. In conclusion, anti-inflammatory gene therapy targeting MCP-1/CCR2 signal, with a novel NP-mediated gene delivery system, is a potent therapeutic strategy for the treatment of cardiovascular diseases.