丝裂素原激活蛋白激酶途径在内毒素激活枯否细胞中的作用

Effect of mitogen-activated protein kinase pathway on Kupffer cell activation by lipopolysaccharide

目的 :探讨丝裂素原激活蛋白激酶 (MAPKs)途径在脂多糖 (L PS)激活枯否细胞 (KC)中的作用。方法 :用 3种 MAPK通路阻滞剂 ,测定其后培养 KC中肿瘤坏死因子 α m RNA(TNFα m RNA)、白介素 6m RNA (IL 6 m RNA )以及诱生型一氧化氮合酶 (i NOS)表达和 TNFα、IL 6以及 NO的释放。结果 :1ERK1/ 2途径抑制剂 (PD0 980 5 9)对 KC中 TNFα m RNA表达和 TNFα的释放影响极小 ,而对 IL 6m RNA和 i NOS的表达以及 IL 6和 NO的释放有明显的抑制作用 ;2 p38MAPK途径抑制剂 (SB2 0 35 80 )对KC中 TNFα m RNA和 IL 6 m RNA表达以及 IL 6和 TNFα的释放影响极小 ,而对 i NOS的表达和 NO的释放有明显的抑制作用 ;3当用 SB2 0 2 4 74抑制整个 MAPK途径时 ,KC中 TNFα、IL 6 m RNA和 i NOS的表达和 TNFα、IL 6以及 NO的释放均明显降低。结论 :TNFα m RNA表达和 TNFα的释放主要受MAPK途径中的 JNK/ SAPK途径的调节 ,IL 6 m RNA表达和 IL 6的释放主要受 MAPK途径中的 ERK1/ 2和 JNK/ SAPK通路的调节 ,而 i NOS的表达和 NO的释放可能与以上 3种途径均有关系。

Objective:To explore the effect of mitogenactivated protein kinase(MAPK) pathway on Kupffer cells(KCs) activation by lipopolysaccharide(LPS).Methods:The expressions of tumor necrosis factorα(TNFα)mRNA,interleukin6(IL6) mRNA and induced nitric oxide synthase(iNOS) or the concentrations of TNFα,IL6 and nitric oxide(NO) were assayed by in situ hybridization or radioimmunoassay in rat KCs activated with LPS after 3 kinds of MAPK pathway inhibitors were used.Results: ①The inhibitor of ERK1/2 (PD098059) had a little influence on the expression of TNFα mRNA and the release of TNFα,but had a strong influence on the expressions of IL6 mRNA,iNOS and the release of IL6 and NO in KCs activated by LPS.②The inhibitor of p38MAPK(SB203580) had a weak influence on the expressions of TNFα mRNA , IL6 mRNA and the release of TNFα and IL6,but had a strong influence on the iNOS expression and NO release in KCs activated by LPS.③The expressions of TNFα mRNA,IL6 mRNA and iNOS as well as the releases of TNFα,IL6,NO in KCs activated by LPS were markedly decreased when the whole MAPK pathway was completely inhibited by SB202474.Conclusions:In KCs activated by LPS,the expression of TNFα mRNA and the release of TNFα were mainly regulated by JNK/SAPK pathway,and the IL6 mRNA expression as well as the IL6 release were mainly regulated by ERK1/2 and JNK/SAPK pathway,while the iNOS expression and NO release may be related with three pathways namely, ERK1/2,p38MAPK and Jun/SAPK.