Heat shock protein 70 suppresses astroglial-inducible nitric-oxide synthase expression by decreasing NF kappa B activation
Heat shock protein 70 suppresses astroglial-inducible nitric-oxide synthase expression by decreasing NF kappa B activation
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DOI：
10.1074/jbc.271.30.17724
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发表时间：
1996-07-26
影响因子：
4.8
通讯作者：
Reis, DJ
中科院分区：
文献类型：
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作者：
Feinstein, DL;Galea, E;Reis, DJ
在脑胶质细胞中，钙非依赖性一氧化氮合酶（NOS-2）的表达在用细菌内毒素（脂多糖（LPS））和/或促炎细胞因子刺激后被诱导。我们已经研究了热休克（HS），这可以减少炎症反应在几种细胞类型，对神经胶质细胞NOS-2的表达诱导的影响。在43 ℃下预孵育细胞20-60分钟降低了随后的NOS-2诱导水平，HS 60分钟后最大降低80%。HS后，细胞难治性NOS诱导剂长达4小时，在此之后的时间很少或没有观察到抑制。HS降低胞质NOS-2酶活性（3倍），稳态mRNA水平（2-3倍）和基因启动子活性（50%）。HS还能抑制LPS诱导的NF κ B B p65亚基在核内的聚集，提示NF κ B B的活化受到干扰。稳定表达人HSP 70的大鼠成纤维细胞在LPS和细胞因子的刺激下不表达NOS 2。与热休克细胞一样，表达HSP 70的细胞也表现出NF κ B B p65亚单位核积累减少。这些结果表明，在神经胶质细胞，以及其他类型的细胞，NOS-2的诱导可以调制的HS响应，介导的至少部分由HSP 70的表达。
In brain glial cells, expression of calcium independent nitric oxide synthase (NOS-2) is induced following stimulation with bacterial endotoxin (lipopolysaccharide (LPS)) and/or pro-inflammatory cytokines. We have investigated the effects of heat shock (HS), which can re duce inflammatory responses in several cell types, on the induction of glial NOS-2 expression. Preincubation of cells for 20-60 min at 43 degrees C decreased subsequent levels of NOS-2 induction, with a maximal 80% reduction after 60 min of HS. Following HS, cells were refractory to NOS inducers for up to 4 h, after which time little or no suppression was observed. HS reduced cytosolic NOS-2 enzymatic activity (3-fold), steady state mRNA levels (2-3-fold), and gene promoter activity (by 50%). HS also reduced LPS induced nuclear accumulation of transcription factor NF kappa B p65 subunit, suggesting perturbation of NF kappa B activation.A role for HS protein (HSP) 70 in NOS-2 suppression by HS is supported by the demonstration that 1) transfection with human HSP70 cDNA partially replicated HS effects; 2) antisense, but not sense, oligonucleotides directed against rat HSP70 partially blocked HS effects; and 3) rat fibroblasts stably expressing human HSP70 did not express NOS-2 in response to LPS plus cytokines. As with heat-shocked cells, HSP70 expressing cells also exhibited decreased NF kappa B p65 subunit nuclear accumulation. These results demonstrate that in glial cells, as well as other cell types, NOS-2 induction can be modulated by the HS response, mediated at least in part by HSP70 expression.