大鼠小肠移植肝脏移植物抗宿主疾病中凋亡及Fas配体的表达

The expression of apoptosis and FASL in hepatic GVHD of intestinal transplantation in rats

目的建立大鼠小肠移植肝脏移植物抗宿主疾病(GVHD)动物模型,探讨细胞凋亡及其Fas系统与肝脏GVHD的关系。方法选用体重为200～250 g的雄性大鼠,对照组为SD-SD大鼠(n=25),实验组为Wistar-SD大鼠(n=25),行大鼠异位全小肠移植术。分别于术后第1、3、5、7、9、11天取肝组织行苏木素-伊红(HE)染色,同时检测肝功,TUNEL法检测肝脏细胞凋亡,免疫组织化学方法检测Fas及其配体(FasL)表达。结果两组术后肝脏功能无明显改变,光镜及电镜亦无明显凋亡性改变。实验组,TUNEL阳性细胞从术后第4天开始出现,并且随着时间的推移呈上升趋势,而对照组无明显增加。免疫组织化学结果,两组Fas在肝脏中广泛表达；而FasL只在实验组的术后第11天广泛表达,与对照组相比差异有统计学意义(P＜0．05)。结论FasL和细胞凋亡可以被当作大鼠小肠移植中早期诊断肝脏GVFID的发生的有效方法之一。

Objective To establish the heterotopic intestinal transplantation model in rats and study the involvement of the apoptosis and Fas system in hepatic GVHD. Methods Male rats weighing from 200 to 250 g were used both as donors and recipients and heterotopic small intestine transplantation models were established. The liver samples were harvested from recipients of either intestinal allografts or isografts on the day 1,3,5,7,9 and 11 posttransplant. Liver function, histology, terminal deoxy-dUTP nick end labeling （TUNEL） staining and immunohistochemistry of Fas/FasL were also observed. Results There was no significant difference in the liver function between two groups. HE staining and electron microscopy revealed no obvious apoptosis changes. In experimental group, the TUNEL positive cells emerged from the day 4 posttransplant and increased steadily, but there was no significant increase in the control group. Immunohistochemical staining showed extensive staining for Fas in both two groups, while FasL was expressed most extensively on the day 11 only in experimental group. Conclusion Early detection of increased Fas ligand and apoptosis is considered as an effective method for the diagnosis of hepatic GVHD in rats.