Adeno-associated virus-mediated transfer of endothelial nitric oxide synthase gene reduces the vasoconstrictive...

Adeno-associated virus (AAV) has a number of attractive features for gene therapy including the ability to transduce nondividing cells and long term transgene expression.

To investigate whether the endothelial constitutive nitric oxide synthase (ecNOS) gene can be efficiently introduced into rat aortic segments using AAV vectors and thereby modulate the vasoconstrictive response.

Excised rat aortas were incubated with medium containing ecNOS-expressing AAV vectors (AAV-ecNOS). Expression of ecNOS in the aortic segments was evaluated by immunohistochemical staining. The isometric tension of the aortic segments transduced with AAV-ecNOS was measured.

Adventitial cells in rat aortic segments were efficiently transduced with AAV-ecNOS. The vasoconstrictive response induced by 30 mmol/L K(+) was enhanced in endothelium-denuded aortic segments compared with intact aortic segments. However, in endothelium-denuded aortic segments transduced with AAV-ecNOS, the enhancement of the vasoconstrictive response disappeared. This effect induced by ecNOS gene transfer was abolished in the presence of the nitric oxide synthase inhibitor N(G)-monomethyl-l-arginine acetate.

These results show that ecNOS gene transfer using AAV vectors abolishes the pathological enhancement of the vasoconstrictive response in endothelium-denuded aortic segments.