内皮源性toll样受体4在急性肺损伤中的作用

目的 探索内皮源性或髓源性细胞表面toll样受体4(TLR4)介入急性肺损伤(ALI)的作用. 方法 采用TLR4基因突变(C3H/HeJ品系,TLR4mut/mut)及野生型(C3H/HeN,TLB4+/+)小鼠,通过骨髓移植建立"内皮细胞TLR4+/+髓系细胞TLR4mut/mut"(WT/Mutant:受体/供体)及Mutant/WT嵌合体小鼠,尾静脉注射LPS(5 mg·kg-1)复制ALI模型,5 h后测肺组织湿干重比(W/D),肺通透指数(LPI),肺组织髓过氧化物酶(MPO)水平、炎症因子及黏附分子水平. 结果 TLR4mut/mut小鼠肺损伤较TLR4+/+小鼠较轻,WT/Mutant组小鼠肺组织损伤较Mutant/WT组重,且WT/Mutant组与WT/WT组差异无统计学意义.WT/Mutant组小鼠肺组织MPO水平、ICAM-1表达水平较Mutant/WT组高,且ICAM-1表达水平WT/Mutant组小鼠与WT/WT小鼠比较差异无统计学意义.炎症因子TNF-α、IL-1β的水平Mutant/WT组较WT/Mutant组高. 结论 内皮源性TLR4通过调控黏附分子表达而促进PMN肺组织招募,在介导LPS诱导的ALI中的发挥核心作用.

The role of endothelial cell derived toll-like receptor 4 acute lung injury

Objective To investigate the role of toll-like receptor 4 (TLR4) of endothelium or bone marrow derived cells in the acute lung injury (ALI) induced by lipopolyscccharide (LPS) in mice with reciprocal bone marrow transplantation. Method Chimeric mice were produced by reciprocal bone marrow transplantation between TLR4mut/mut and TLR4+/+ mice and divided into 4 groups: WT/WT (recipient/donor),WT/Mutant, Mutant/WT and Mutant/Mutant group. Six to eight weeks following transplantation, LPS was injected inot mice's tail vein in order to produce ALI model,and mice were sacrificed five hours later on.Samples of lung tissues were taken for the following analysis of wet/dry weight (W/D), lung permeabifity index (LPI), myeloperoxidase (MPO),levels of cytokines (TNF-α, IL-1β) and adhesion molecules (ICAM-1). Results Lung injury in the Mutant/Mutant mice was the mildest in the 4 groups. And lung injury in WT/Mutant mice was more serious than that in Mutant/WT mice. levels of MPO and ICAM-1 in WT/Mutant mice were much higher than those of Mutant/WT. In addition,the expression of ICAM-1 in WT/Mutant mice is comarable to that in WT/WT mice. Mutant/WT mice expressed higher levels of TNF-α and IL-1β than WT/Mutant mice. Conclusions Endothelial cell derived TLR4 plays ker-nel role in ALI induced by LPS via lung PMN recruitment,although bone marrow cells derived TLR4 are more im-portant for the release of cytokines.