IL-12/STAT4途径激活对同种部分肝移植排斥反应的影响

Effect of activation of IL-12/STAT4 signaling pathway on rejection of partial liver allograft in rat

目的 探讨白细胞介素 12 /信号传导子及转录激活子 (IL 12 /STAT4)信号途径激活在同种部分肝移植排斥中的作用。方法 将供者SD大鼠与受者LEW大鼠随机分为 4组 ,每组供、受者各 40只。A组 :全肝移植组 ;B组 :部分肝移植组 ;C组 :部分肝移植 +IL 12硫代修饰反义寡脱氧核苷酸 (ASPODN )治疗组 ;D组 :部分肝移植 +IL 12硫代修饰正义寡脱氧核苷酸 (SPODN)对照治疗组。观察移植肝排斥病理以及受者存活时间。分别采用Western blot及EMSA检测肝移植后 0h和4d移植肝IL 12蛋白表达、STAT4蛋白表达及其DNA结合活性 ;ELISA检测受者血清IL 2、IL 10及IFN γ水平。结果 B组和D组移植肝于移植后 4d出现排斥反应 ,早于A组和C组。B组受者存活时间 (13 .5± 0 .48)d ,较A组存活时间 (2 2 .6± 0 .59)d明显缩短 (P <0 .0 0 1) ;C组存活时间 (56.8±2 .5)d ,明显长于A组和B组 (P <0 .0 0 1)。肝移植后 4d ,移植肝IL 12、STAT4蛋白表达及其DNA结合活性、受者血清IL 2、IL 10和IFN γ水平 ,B组较A组明显增高 (P <0 .0 0 1) ,C组较B组明显降低 (P <0 .0 0 1) ,D组各项指标与B组相似。结论 IL 12 /STAT

ObjectiveTo investigate the effect of activation of IL-12/STAT4 signaling pathway on rejection of allogeneic partial liver allograft in rats.MethodsRecipient LEW rats and donor SD rats were randomly divided into the following gr oups: group A (n=40) served as whole liver transplantation group; group B ( n=40) as partial liver transplantation group in which LEW rats received 50 ?% partial liver graft of SD rats; group C (n=40) were treated with IL-12 ASPODNs in which liposomes encapsulated IL-12 p35 ASPODN and IL-12 p40 ASPODN were intraperitoneally injected on 0?h and 48?h after partial liver tran splantation; group D in which IL-12 ASPODNs were replaced with IL-12SPODNs. Th e rejection pathological characters of liver grafts were observed under a micros cope, and the postoperative survival time of the recipients from each group were recorded. The expression of IL-12 protein and STAT4 (signal transducer and act ivator of transcription, STAT) protein in liver grafts was detected by using Wes tern-blotting. DNA binding activity of STAT4 was measured by EMSA. Serum levels of IL-10, IL-2 and IFN-γ were determined by ELISA.ResultsAllogeneic partial liver grafts 4 days after transplantation from group B and group D demonstrated accelerated rejection as compared with groups A and C. Rec ipients from group B had a shorter survival of ( 13.5 ± 0.48 ) days (P < 0.001 vs group A), whereas the recipients from group C had a longer sur vival of ( 56.8 ± 2.5 ) days (P< 0.001 vs groups A and B, respectiv ely). The expression of IL-12 protein, STAT4 protein and DNA binding activity o f STAT4 in liver grafts, and serum level of IL-10, IL-2 and IFN-γ were sign ificantly increased in group B (P< 0.001 vs group A) and markedly decreased in group C (P< 0.001 vs group B) 4 days after transplantation. In contrast to IL-12 ASPODNs, IL-12 SPODNs had few effects on rejection of pa rtial liver graft.ConclusionActivation of IL-12/ STAT4 signaling pathway would be an important mechanism of rejection of partial liver allograft.