Abstract
Background: Inflammation plays an important role in neointimal hyperplasia after vascular injury. COX-2 is a key mediator of inflammation and contributes to several inflammatory diseases. Although selective COX-2 inhibitors affect pathological conditions in inflammatory diseases, little is known about the effects on vascular remodeling after mechanical injury. Methods: To clarify the role of COX-2 in vascular remodeling after arterial injury, we made a wire-injury model using C57BL/6J mice. These mice were orally administrated a selective COX-2 inhibitor twice a day. COX-2 mRNA expression was analyzed in injured femoral arteries. Results: COX-2 expression was markedly enhanced in the arterial wall on day 7; the expression was gradually decreased from day 14. In histopathological analyses, the COX-2 inhibitor significantly suppressed the progression of neointimal formation in comparison with non-treated mice. In an in vitro study, RNA was collected from macrophages after stimulation. The stimulation resulted in enhanced expression of IL-6 compared with the control, and the COX-2 inhibitor decreased this expression. Conclusion: COX-2 is enhanced in the neointima after mechanical injury, and inhibition attenuated this. Therefore, regulation of COX-2 may be useful for preventing neointimal formation after coronary intervention.
Acknowledgements
We thank Ms Noriko Tamura and Ms Yasuko Matsuda for excellent technical assistance.