巨噬细胞诱导型C型凝集素参与尿毒症微炎症状态及机制

The mechanism of macrophage-inducible C-type lectin involved in uremic microinflammatory state

目的探讨巨噬细胞诱导型C型凝集素(macrophage-inducible C-type lectin,Mincle)参与尿毒症微炎症状态的机制。方法SD大鼠随机分为假手术组和5/6肾切除手术建立的尿毒症组。检测肠道组织形态及通透性;透射电子显微镜观察肠道组织及肠巨噬细胞形态;免疫组化法检测肠组织切片中Mincle的表达;Western blotting检测巨噬细胞表面的Toll样受体4(Toll-like receptor 4,TLR4)和NF-κB蛋白的表达。分离出血浆后,用鲎试剂动态浊度定量检测法检测血中内毒素,散射免疫比浊法检测C反应蛋白(C reactive protein,CRP),酶联免疫吸附法检测白细胞介素-6(interleukin-6,IL-6)及肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)水平,并进行统计学分析。结果尿毒症组空肠、回肠、结肠Mincle表达高于假手术组(P<0.05);尿毒症组的回肠、空肠、结肠TLR4、NF-κB蛋白表达差异有统计学意义(P均<0.001);尿毒症组血中的内毒素、CRP、IL-6、TNF-α水平较假手术组显著增加(P<0.05)。结论尿毒症时肠道巨噬细胞表面的Mincle增高并进一步通过TLR4/NF-κB通路介导肠道巨噬细胞向M1型转化,释放炎症产物引起全身微炎症状态。

Objective To explore the mechanism of macrophage-inducible C-type lectin(Mincle)and microinflammatory state in uremia.Methods SD rats were randomly divided into uremia group and sham operation group.The morphology and permeability of intestinal tissue,the morphology of intestinal tissue and macrophages were observed by transmission electron microscope,the expression of Mincle was detected in intestinal tissue sections,and the expressions of Toll-like receptor 4(TLR-4)and NF-kappa B(NF-κB)protein on the surface of macrophages were detected by Western blotting.After the plasma was separated,the levels of endotoxin,C-reactive protein(CRP),interleulin-6(IL-6)and tumor necrosis factor-α(TNF-α)were detected by Limulus lysate dynamic turbidimetric assay,and enzyme-linked immunosorbent assay(ELISA).The data were analyzed with IBM SPSS19.0 software.Results The expression of Mincle in the jejunum,ileum,and colon in uremia group was higher than that in sham-operation group(P<0.05).The expressions of TLR4 and NF-κB protein significantly differed in the ileum,jejunum and colon in uremia group(P<0.001).The levels of endotoxin,CRP,IL-6,and TNF-αwere significantly increased in uremia group compared with sham-operation group(P<0.05).Conclusion In uremia,Mincle on the surface of intestinal macrophages increases and further through TLR4/NF-κB pathway mediates the transformation of intestinal macrophages to M1 type,releasing inflammatory products and causing systemic microinflammation.