Activation of c-Jun N-terminal kinase in bacterial lipopolysaccharide-stimulated macrophages
Activation of c-Jun N-terminal kinase in bacterial lipopolysaccharide-stimulated macrophages
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DOI：
10.1073/pnas.93.7.2774
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发表时间：
1996-04-02
影响因子：
11.1
通讯作者：
DeFranco, AL
中科院分区：
文献类型：
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作者：
Hambleton, J;Weinstein, SL;DeFranco, AL
细菌脂多糖（LPS）激活巨噬细胞，诱导编码免疫反应促炎调节因子的基因转录。先前的研究表明，转录因子激活蛋白 1 (AP-1) 的激活是 LPS 诱导的介导这种反应的事件之一。与这一观点一致，我们发现LPS刺激小鼠巨噬细胞系RAW 264.7中转染的报告基因的AP-1介导的转录，由于AP-1活性部分通过c-Jun N末端激酶(JNK)的激活来调节，JNK磷酸化并随后增加c-Jun的转录活性，我们检查了巨噬细胞的LPS处理是否导致了 这种激酶。 LPS 处理 RAW 264.7 细胞、鼠骨髓源性巨噬细胞和人单核细胞系 THP-1 导致 JNK 的 p46 和 p54 亚型快速激活，用野生型和粗突变型 LPS 和合成脂质 A 处理导致 JNK 激活，而用酪氨酸激酶抑制剂除草霉素 A 预处理则抑制 JNK 激活。 LPS-LPS结合蛋白(LBP)复合物与CD14(介导许多LPS反应的表面受体)的结合被发现是至关重要的，因为用单克隆抗体60b预处理THP-1细胞，其阻断这种结合，抑制JNK活化。这些结果表明单核细胞/巨噬细胞中JNK的LPS活化是CD14-和 蛋白酪氨酸磷酸化依赖性事件可能介导 AP-1 的早期激活，从而调节 LPS 触发的基因诱导。
Activation of macrophages by bacterial lipopolysaccharide (LPS) induces transcription of genes that encode for proinflammatory regulators of the immune response. Previous work has suggested that activation of the transcription factor activator protein 1 (AP-1) is one LPS-induced event that mediates this response. Consistent with this notion, we found that LPS stimulated AP-l-mediated transcription of a transfected reporter gene in the murine macrophage cell line RAW 264.7, As AP-1 activity is regulated in part by activation of the c-Jun N-terminal kinase (JNK), which phosphorylates and subsequently increases the transcriptional activity of c-Jun, we examined whether LPS treatment of macrophages resulted in activation of this kinase. LPS treatment of RAW 264.7 cells, murine bone marrow-derived macrophages, and the human monocyte cell line THP-1 resulted in rapid activation of the p46 and p54 isoforms of JNK, Treatment with wild-type and rough mutant forms of LPS and synthetic lipid A resulted in JNK activation, while pretreatment with the tyrosine kinase inhibitor herbimycin A inhibited this response, Binding of LPS-LPS binding protein (LBP) complexes to CD14, a surface receptor that mediates many LPS responses, was found to be crucial, as pretreatment of THP-I cells with the monoclonal antibody 60b, which blocks this binding, inhibited JNK activation, These results suggest that LPS activation of JNK in monocyte/macrophage cells is a CD14- and protein tyrosine phosphorylation-dependent event that may mediate the early activation of AP-1 in regulating LPS-triggered gene induction.