肠移植早期黏膜地址素细胞黏附分子在大鼠移植小肠及其肠系膜淋巴结的表达

Expression of mucosal addressin cell adhesion molecule-1 during small bowel graft rejection in rat

目的探讨黏膜地址素细胞黏附分子(MAdCAM-1)在大鼠小肠移植早期移植肠及其肠系膜淋巴结中的表达及意义。方法选用近交系F_(344)/N和BN大鼠建立全小肠异位移植模型后分3组：第1组,非手术对照组(F_(344)/N)；第2组,同基因移植组(F_(344)/N→F_(344)/N)；第3组,异基因移植组(BN→F_(344)/N)。术后1、3、5、7 d取各组移植肠及其肠系膜淋巴结检测MAdCAM-1表达的分布及变化,同期进行移植肠组织病理学检查。结果同基因移植组各检测时点的肠黏膜组织表现与正常小肠的组织学特征基本相同；异基因移植组肠黏膜组织表现符合轻→中→重度排斥反应的渐进过程,2周后移植肠绒毛变的低平,散在黏膜上皮脱落,移植肠相关肠系膜淋巴结萎缩明显。MAdCAM-1在急性排斥反应期,高表达于移植肠固有层及其肠系膜淋巴结,特别是高表达于肠黏膜固有层中的扁平血管内皮细胞表面。同基因移植组术后MAdCAM-1的表达在1-7 d均无明显量的变化；而异基因移植组MAdCAM-1在移植肠中的表达呈上升趋势,而在其肠系膜淋巴结中的表达呈下降趋势。结论MAdCAM-1与小肠移植急性排斥反应的进展关系密切。

Objective To investigate the expression of mucosal addressin cell adhesion moleeule-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 syngenele 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 highlyexpressed 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.