氯化钆阻断大鼠原位肝移植免疫耐受的分子机制

The molecular mechanism of GdCl3 blocking liver allograft acceptance

目的观察氯化钆（GdCl3）阻断枯否细胞（KCs）功能对大鼠移植肝脏中KCs核因子（NF）-κB活性的影响，探讨NF—κB活性与FasL及细胞因子基因转录的关系。方法肝移植术后1、2和4h活杀动物，取肝脏分离KCs，分别用凝胶电迁移率改变分析法（EMSA）、Western blot蛋白印迹法和逆转录-聚合酶链反应（RT—PCR）法检测KCs中NF—κB活性、Fas／FasL基因和蛋白质的表达及细胞因子白细胞介素（IL）-4和TNF-α基因转录。结果GdCl3组KCs中NF-κB活性受到明显抑制，术后2、4h FasL和细胞因子IL-4基因转录和蛋白的表达也明显减少（P〈0．05），但术后2h TNF-α基因转录没有显著减少（P〉0．05）。结论GdCl3可能阻断KCs中NF—κB活性，使KCs中FasL及IL-4的基因和蛋白表达减少，影响移植肝脏免疫耐受的形成。

Objective To observe the change of nuclear factor （NF）-κB in Kupffer cells （KCs） ,demonstrate the inhibitory effects of GdCl3 on NF-κB activity and the expression of FasL mRNA and protein, and elucidate the molecular mechanism of liver allograft acceptance. Methods Nuclear protein, membrane protein and total RNA were extracted from KCs in the liver grafts of the rats. NF-κB activity was measured by using electrophoretic mobility shift assay （EMSA）. The expression of Fas/FasL mRNA and proteins was detected by using RT-PCR and Western blot, respectively. The expression levels of IL-4 and TNF-α mRNA were examined by using RT-PCR. Results NF-κB activity in the liver transplantation group was higher than that in GdCl3 group 1 h,2 h and 4 h after operation. The expression of FasL and IL- 4 mRNA in the GdCl3 group was decreased as compared with that in liver transplantation group both 2 h and 4 h after operation （ P 〈 0.05 ）. The expression of TNF-α mRNA had no significant difference in GdCl3 group both 2 h and 4 h after operation （ P 〉 0.05 ）. Conclusion GdCl3 could suppress the expression of FasL in KCs via inhibiting activity of NF-κB and blocking induction of liver graft tolerance.