Objective: To investigate the expression of mucosal addressin cell adhesion molecule-1(MAdCAM-1) during small bowel graft rejection and the effects of MAdCAM-1 on the development of acute rejection.
Methods: Rat heterotopic small bowel transplantation (SBT) was performed in F344/N rats with syngeneic and allogeneic (BN-F344/N) grafts. Bowel and gut-associated lymphoid tissue(GALT) samples were collected from small bowel transplants on postoperative day(POD) 1, 3, 5 and 7. Histopathology assessment of the grafts was conducted to identify the rejection. MAdCAM-1 was detected by immunohistochemistry and Western blot.
Results: During acute rejection, MAdCAM-1 was highly-expressed on gut lamina propia and GALTs, particularly on vascular endothelial cells in the gut lamina propia. There were no change of MAdCAM-1 expression in syngeneic grafts from POD1 to POD7. In allogeneic grafts, MAdCAM-1 expression in mesenteric lymph nodes was down-regulated, while up-regulated on the vascular endothelial cells in the lamina propria during acute rejection.
Conclusion: Alteration of MAdCAM-1 expression may be associated with the development of SBT graft rejection.