C-reactive protein induces high-mobility group box-1 protein release through activation of p38MAPK in macrophage RAW264.7 cells
C-reactive protein induces high-mobility group box-1 protein release through activation of p38MAPK in macrophage RAW264.7 cells
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DOI：
10.1016/j.carpath.2007.08.006
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发表时间：
2008-05-01
影响因子：
3.7
通讯作者：
Maruyama, Ikuro
中科院分区：
文献类型：
--
作者：
Kawahara, Ko-ichi;Biswas, Kamal Krishna;Maruyama, Ikuro
背景：C反应蛋白（CRP）是一种敏感的炎症生物标志物。越来越多的证据表明CRP在炎症中起作用。高迁移率族蛋白-1（HMGB 1）是一种主要的核蛋白，由坏死或受损细胞被动释放到细胞外环境中，并由单核细胞/巨噬细胞主动分泌。细胞外高迁移率族蛋白1（HMGB 1）作为一种强有力的炎症介质，在炎症研究领域引起了极大的兴趣。然而，CRP和HMGB 1在延迟炎症过程中的分子对话仍有待探讨。方法与结果：采用Western blot和酶联免疫吸附试验检测培养上清中HMGB 1的表达水平。纯化的CRP以剂量和时间依赖性方式诱导HMGB 1的释放。免疫荧光分析显示，HMGB 1的核转位反应CRP。通过荧光激活细胞分选仪分析证实了RAW264.7细胞中CRP与Fc γ受体的结合。用IgG-Fc片段而不是IgG-Fab片段预处理细胞有效地阻断了这种结合。CRP可激活p38 MAPK和ERK 1/2，但不激活Jun N端激酶。此外，p38 MAPK抑制剂SB 203580和小干扰RNA均显著抑制HMGB 1的释放，但不抑制MEK 1/2抑制剂U-0126。结论：我们首次证明，CRP，一个突出的风险标志物炎症，包括动脉粥样硬化，可以诱导HMGB 1的主动释放RAW264.7细胞通过Fc γ受体/p38 MAPK信号通路，从而暗示CRP在诱导，放大，并延长炎症过程中起着至关重要的作用，包括动脉粥样硬化病变。(C)2008年爱思唯尔公司All rights reserved.
Background: C-reactive protein (CRP) is widely used as a sensitive biomarker for inflammation. Increasing evidence suggests that CRP plays a role in inflammation. High-mobility group box-1 (HMGB1), a primarily nuclear protein, is passively released into the extracellular milieu by necrotic or damaged cells and is actively secreted by monocytes/macrophages. Extracellular HMGB1 as a potent inflammatory mediator has stimulated immense curiosity in the field of inflammation research. However, the molecular dialogue implicated between CRP and HMGB1 in delayed inflammatory processes remains to be explored. Methods and results: The levels of HMGB1 in culture supernatants were determined by Western blot analysis and enzyme-linked immunosorbent assay in macrophage RAW264.7 cells. Purified CRP induced the release of HMGB1 in a dose- and time-dependent fashion. Immunofluorescence analysis revealed nuclear translocation of HMGB1 in response to CRP. The binding of CRP to the Fc gamma receptor in RAW264.7 cells was confirmed by fluorescence-activated cell sorter analysis. Pretreatment of cells with IgG-Fc fragment, but not IgG-Fab fragment, efficiently blocked this binding. CRP triggered the activation of p38MAPK and ERK1/2, but not Jun N-terminal kinase. Moreover, both p38MAPK inhibitor SB203580 and small interfering RNA significantly suppressed the release of HMGB1, but not the MEK1/2 inhibitor U-0126. Conclusion: We demonstrated for the first time that CRP, a prominent risk marker for inflammation including atherosclerosis, could induce the active release of HMGB1 by RAW264.7 cells through Fc gamma receptor/p38MAPK signaling pathways, thus implying that CRP plays a crucial role in the induction, amplification, and prolongation of inflammatory processes, including atherosclerotic lesions. (C) 2008 Elsevier Inc. All rights reserved.