Mouse model of transplant arteriosclerosis - Role of intercellular adhesion molecule-1

Transplant-accelerated arteriosclerosis in coronary arteries is the major l imitation to long-term survival of patients with heart transplantation. The pathogenesis of this disease is not fully understood. Herein, we describe a simplified model of artery allografts in the mouse that allows us to take advantage of transgenic, knockout, or mutant animals, Common carotid arter ies or aortic vessels were end-to-end allografted into carotid arteries bet ween C57BL/6J and BALB/c mice. Neointimal lesions were observed as early as 2 weeks after surgery and had progressed at 4 and 6 weeks postoperatively. The lumen of grafted arteries was significantly narrowed due to neointima hyperplasia 4 weeks after transplantation. Using this model, we studied the role of intercellular adhesion molecule-1 (ICAM-1) in the development of t ransplant arteriosclerosis in ICAM-1-deficient mice. Neointimal lesions of artery grafts from ICAM-1 -/- C57BL/6J to BALB/c mice were reduced up to 60 % compared with wild-type controls, MAC-1 (CD11b/18)-positive cells adherin g to the surface of ICAM-1 -/- artery grafts were significantly less as ide ntified by en face immunofluorescence, and these positive cells were more a bundant in intimal lesions of artery grafts in wild-type mice. Furthermore, the major cell component of neointimal lesions 4 weeks after surgery was f ound to be alpha-actin-positive smooth muscle cells, which were significant ly reduced in lesions of ICAM-1 -/- artery grafts. Thus, this model has bee n proven to be useful for understanding the mechanism of transplant arterio sclerosis. Our findings demonstrate that ICAM-1 is critical in the developm ent of allograft arteriosclerosis via mediation of leukocyte adhesion to, a nd infiltration into, the vessel wall.