急性肝损伤过程中肝内不同来源巨噬细胞的作用研究

摘要

Objective To elaborate the role of hepatic inherent macrophages and monocyte-derived macrophages in acute liver injury.Methods A model of acute liver injury in mice was induced via intraperitoneally injection of CCl 4 .Af-ter CCl4 injection, analysis of the expression of CD45, F4/80, Ly6C and CD11b on the hepatic macrophage surface was performed by flow cytometry at 24, 48 and 72 h before the hepatic inherent macrophages (CD45+F4/80hi) and monocyte-de-rived macrophages ( CD45+F4/80 lo ) were sorted at the same time .The relative expression of cytokines in the two popula-tions of macrophages was detected by qRT-PCR.Results Compared with control , the number of total F4/80 +cells in the liver was markedly increased after CCl 4 injection, especially at 72 h.The number of CD45+F4/80lo cells increased signifi-cantly after CCl4 injection 24 h.The mRNA levels of MCP-1, TNF-α, TGF-β1, matrix metalloproteinase(MMP)-12 and MMP-13 were elevated significantly both in F 4/80 hi and F4/80 lo macrophages .IL-12βand IL-6 mRNA levels increased significantly only in F4/80hi macrophages, while the level of MMP-9 mRNA increased markedly only in F4/80lo macropha-ges.When compared with F4/80lo macrophages, MCP-1 and MMP-12 mRNA levels were elevated significantly , while the level of TNF-αmRNA decreased significantly in F4/80hi macrophages.Conclusion In acute liver injury, hepatic inherent macrophages and monocyte-derived macrophages both express inflammatory cytokines , promoting inflammation response and leading to liver damage .The ability to recruit inflammatory monocytes into the liver is much stronger ,the expression of in-flammatory cytokines ( IL-12βand IL-6 ) and MMP-12 is higher , but the expression of inflammatory cytokines ( TNF-α) MMP-9 is lower in hepatic inherent macrophages than in monocyte-derived macrophages .%目的：急性肝损伤过程中，肝脏内存在来源不同的两类巨噬细胞即肝脏固有巨噬细胞和单核细胞源性巨噬细胞。该研究明确这两类巨噬细胞在急性肝损伤过程中的作用。方法采用腹腔注射四氯化碳（ CCl 4）构建急性肝损伤小鼠模型，通过流式细胞术分析注射CCl4后24、48、72 h时小鼠肝内巨噬细胞表面抗原（ CD45， F4/80， Ly6C和CD11b）的表达情况，分选出肝脏固有巨噬细胞（CD45＋F4/80hi）和单核细胞源性巨噬细胞（CD45＋F4/80lo），并应用qRT-PCR检测两群巨噬细胞中细胞因子的表达情况。结果与正常对照相比，注射CCl4后24、48、72 h时小鼠肝内总F4/80＋细胞数显著增加，尤其是72 h时；24 h CD45＋F4/80 lo细胞数显著增加。急性肝损伤过程中，与正常对照相比，F4/80hi巨噬细胞和F4/80lo巨噬细胞中MCP-1、TNF-α、TGF-β1、基质金属蛋白酶（MMP）-12和MMP-13 mRNA水平均显著升高，IL-12β和IL-6 mRNA水平只在F4/80 hi巨噬细胞中显著升高，MMP-9 mRNA水平只在F4/80lo巨噬细胞中显著升高。与F4/80lo巨噬细胞相比，F4/80hi巨噬细胞中MCP-1和MMP-12 mRNA水平显著升高， TNF-αmRNA水平显著降低。结论急性肝损伤时，肝内固有巨噬细胞和单核细胞源性巨噬细胞均表达炎性细胞因子，促进炎症反应，导致肝损伤；肝内固有巨噬细胞募集炎性单核细胞的能力和表达炎性细胞因子（ IL-12β， IL-6）、MMP-12的能力强于单核细胞源性巨噬细胞；单核细胞源性巨噬细胞表达炎性细胞因子（ TNF-α）和MMP-9的能力强于固有巨噬细胞。