Blockade of p38 mitogen-activated protein kinase pathway inhibits inducible nitric-oxide synthase expression in mouse astrocytes
Blockade of p38 mitogen-activated protein kinase pathway inhibits inducible nitric-oxide synthase expression in mouse astrocytes
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DOI：
10.1074/jbc.272.45.28373
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发表时间：
1997-11-07
影响因子：
4.8
通讯作者：
Lesslauer, W
中科院分区：
文献类型：
--
作者：
DaSilva, J;Pierrat, B;Lesslauer, W
用白细胞介素(IL)-1 α和肿瘤坏死因子(TNF)- α联合处理小鼠星形胶质细胞培养物诱导诱导型一氧化氮合酶（iNOS）的表达，导致大量一氧化氮的持续释放，而TNF- α和IL-1 α单独不能诱导星形胶质细胞中iNOS的表达。在tnf - α /IL-1 α刺激的星形胶质细胞中，研究了MAPK级联和NF-kappa B激活在参与iNOS转录的早期细胞内信号转导中的作用。tnf - α和IL-1 α激活了所有的p42/44（MAPK）、p38（MAPK）和p54（JNK）通路。p38（MAPK）通路专门参与tnf - α /IL-1 α诱导的iNOS表达，因为在p38（MAPK）的特异性抑制剂4-（4-氟苯基）-2 -2-（4-羟基苯基）-5-（4-吡啶基）-咪唑（FHPI）存在下，iNOS蛋白和一氧化氮的释放显著减少。相比之下，MEK1的特异性抑制剂PD98059对iNOS的表达没有影响，p38（MAPK）没有将NF-kappa B与iNOS的转录偶联，但NF-KB在NOS的转录调节中有明确的作用，Northern blot分析显示p38（MAPK）途径在转录水平上控制iNOS的表达，因为在tnf - α /IL-1 α刺激的星形胶质细胞中，FHPI存在时iNOS mRNA减少。在TNF受体(TNFR)-1-和TNFR-2缺陷小鼠中研究了iNOS的表达，TNF- α /IL-1 α刺激的星形胶质细胞中TNF- α活性完全通过TNFR-1介导，很可能是因为星形胶质细胞中TNFR-2介导的信号没有连接到p38（MAPK）途径。这些数据表明，除了p38（MAPK）外，tnf - α /IL-1 α诱导的iNOS表达还依赖于尚未确定的第二途径。
Treatment of mouse astrocyte cultures with combined interleukin (IL)-1 alpha and tumor necrosis factor (TNF)-alpha induced expression of inducible nitric-oxide synthase (iNOS), resulting in sustained release of large amounts of nitric oxide, whereas TNF-alpha and IL-1 alpha individually were unable to induce iNOS expression in astrocytes. The role of MAPK cascades and of NF-kappa B activation in the early intracellular signal transduction involved in iNOS transcription in TNF-alpha/IL-1 alpha-stimulated astrocytes was investigated. TNF-alpha and IL-1 alpha activated all p42/44(MAPK), p38(MAPK), and p54(JNK) pathways as determined by immunoprecipitation kinase assays using specific antibodies and substrates, The p38(MAPK) pathway is specifically involved in TNF-alpha/IL-1 alpha-induced iNOS expression, since iNOS protein and nitric oxide release in the presence of a specific inhibitor of p38(MAPK), 4-(4-fluorophenyl)-2 -2-(4-hydroxyphenyl)-5-(4-pyridyl)-imidazole (FHPI), were dramatically diminished. In contrast, PD98059, a specific inhibitor of MEK1 had no effect on iNOS expression, p38(MAPK) did not couple NF-kappa B to iNOS transcription, but NF-KB had a clear role in NOS transcription regulation, Northern blot analysis showed that the p38(MAPK) pathway controlled iNOS expression at the transcriptional level, since iNOS mRNA was reduced in the presence of FHPI in TNF-alpha/IL-1 alpha-stimulated astrocytes. iNOS expression was investigated with TNF receptor (TNFR)-1- and TNFR-2-deficient mice, The TNF-alpha activity in TNF-alpha/IL-1 alpha-stimulated astrocytes was exclusively mediated through TNFR-1, most likely because TNFR-2-mediated signals in astrocytes did not connect to the p38(MAPK) pathway. These data suggest that TNF-alpha/IL-1 alpha-induced iNOS expression depends on a yet undetermined second pathway in addition to p38(MAPK).