αGVHD小鼠靶器官组织TLR4/MyD88/NF-κB信号通路蛋白表达变化及意义

Expression changes of TLR4/MyD88/NF-κB signaling pathway in target organs of mice with acute graft-versus-host disease

目的探讨异基因骨髓移植(allo-BMT)后急性移植物抗宿主病(aGVHD)小鼠模型靶器官组织中Toll样受体4(TLR4)/髓样分化蛋白88(MyD88)/核转录因子κB(NF-κB)信号通路蛋白表达变化及意义。方法以C57BL/6雄性小鼠和BALB/c雌性小鼠为allo-BMT的供、受鼠,受鼠接受白舒非+环磷酰胺方案致死剂量预处理后,输注供鼠来源骨髓细胞及脾脏淋巴细胞,建立aGVHD模型(aGVHD组)。以BALB/c雄性小鼠和BALB/c雌性小鼠为同基因骨髓移植(Syn-BMT)的供、受鼠,受鼠经等剂量药物预处理后输注供鼠来源骨髓细胞,建立Syn-BMT模型为对照(Syn-BMT组)。移植后第14天,两组分别取5只存活小鼠,处死后取肝、肠、脾及皮肤组织,分别采用实时荧光定量PCR、Western blotting及免疫组化法检测各组织中TLR4、MyD88、NF-κB p65、NF-κB p50 mRNA及蛋白相对表达量、蛋白阳性表达率。结果 aGVHD组肝、肠、脾和皮肤组织中TLR4、MyD88、NF-κB p65、NF-κB p50mRNA相对表达量及蛋白相对表达量、蛋白阳性表达率均较Syn-BMT对照组增加(P均<0.05)。结论 aGVHD模型小鼠肝、肠、脾和皮肤组织中TLR4/MyD88/NF-κB信号通路蛋白在基因水平和蛋白水平均表达上调。TLR4/MyD88/NF-κB信号通路可能参与了allo-BMT后aGVHD的发病过程。

Objective To investigate the expression changes of Toll-like receptor-4 （TLR4）/myeloid differentiation primary response gene 88 （MyD88）/nuclear factor-κB （NF-KB） signaling pathway protein in mice with acute graft-versus- host disease （aGVHD） after allogeneic bone marrow transplantation （allo-BMT）. Methods Allogeneic bone marrow trans- plantation was performed with C57BL/6 male mice as donors and BALB/C female mice as recipients. The aGVHD models of mice （aGVHD group） were established by injecting the donor bone marrow cells and splenic lymphocytes after the recipients were treated with the lethal dose preconditioning regimen of Busulfan ＋ cyclophosphamide. Syngeneic bone marrow transplan- tation （Syn-BMT） was performed with BALB/C male mice as donors and BALB/C female mice as recipients. The bone mar- row ceils from donor mice were injected into the recipient mice after equal dose of preconditioning regimen, and the syngeneic bone marrow transplantation model was established as the control group. On the 14 day after transplantation, 5 survival mice were taken from the aGVHD group and the control group, respectively. The liver, intestine, spleen, and skin tissues were taken from the mice. Real-time quantitative polymerase chain reaction （ qRT-PCR）, Western blotting, and immunohisto- chemistry were used to detect the mRNA and protein expression rates of TLR4, MyD88, NF-κB p65 and pS0 in the target or- gans of mice. Results The mRNA expression and protein expression, and the the protein expression rates of TLR4, MyD88, NF-κB p65 and pS0 in the liver, intestine, spleen, and skin tissues of the GVHD group were higher than those of Syn-BMT control group （all P 〈0.05）. Conclusion The expression of TLR4/MyD88/NF-κB signaling pathway protein in the liver, intestine,spleen and skin of aGVHD model mice is up-regulated at the gene level and protein level, suggesting that the TLR4/MyD88/NF-κB signaling pathway may be involved in the pathogenesis of aGVHD after allo-BMT.