Cytokine-induced nitric oxide synthase gene transcription is blocked by the heat shock response in human liver cells.
Cytokine-induced nitric oxide synthase gene transcription is blocked by the heat shock response in human liver cells.
复制标题
细胞因子诱导的一氧化氮合酶基因转录被人肝细胞的热休克反应所阻断。
DOI：
10.1016/s0039-6060(96)80281-9
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发表时间：
1996
期刊：
影响因子：
3.8
通讯作者：
Geller,DA
中科院分区：
文献类型：
--
作者：
deVera,ME;Wong,JM;Zhou,JY;Tzeng,E;Wong,HR;Billiar,TR;Geller,DA
研究背景热休克反应（HSR）抑制了精氨酸刺激的肝细胞一氧化氮（NO）合成和诱导型NO合酶（NOS 2）的表达。在这项研究中，我们试图确定这种抑制的分子基础，使用人肝细胞line.MethodsAfter诱导的HSR的亚砷酸钠或高温，AKN-1人肝细胞系用细胞因子刺激NOS 2的表达和NO的生产。Western blot分析热休克蛋白70，并定量NOS 2 mRNA和24小时NO合成。测量了用7.0千碱基NOS 2启动子荧光素酶构建体转染的AKN-1细胞的细胞因子诱导的NOS 2启动子活性以及用NOS 2基因转导的AKN-1细胞的NO产生。结果亚砷酸钠或高温诱导AKN-1细胞中hsp 70蛋白的合成，表明HSR的激活。细胞因子刺激高水平的NOS 2 mRNA和NO的产生。然而，预先诱导HSR显着抑制NOS 2表达和NO合成。细胞因子刺激的转染AKN-1细胞的NOS 2启动子活性下降了77%，但HSR并没有影响转导AKN-1 cells.ConclusionsThese研究结果表明，HSR通过阻止NOS 2启动子的激活，抑制精氨酸诱导的AKN-1细胞NOS 2表达和NO合成。未观察到对NOS 2蛋白翻译或稳定性的影响。这些数据表明，在创伤、休克或缺血再灌注后在肝脏中表达的HSR在转录水平上阻断了NOS 2基因的表达。
BackgroundPreviously we demonstrated that the heat shock response (HSR) inhibits cytokine-stimulated nitric oxide (NO) synthesis and inducible NO synthase (NOS2) expression in hepatocytes. In this study we sought to determine the molecular basis of this inhibition using a human liver cell line.MethodsAfter induction of the HSR by sodium arsenite or hyperthermia, the AKN-1 human liver cell line was treated with cytokines to stimulate NOS2 expression and NO production. Western blot analysis for hsp 70 was performed, and NOS2 mRNA and 24-hour NO synthesis were quantitated. Cytokine-induced NOS2 promoter activity of AKN-1 cells transfected with a 7.0 kilobase NOS2 promoter luciferase construct and NO production of AKN-1 cells transduced with the NOS2 gene were measured.ResultsSodium arsenite or hyperthermia induced the synthesis of hsp 70 protein in AKN-1 cells, indicating activation of the HSR. Cytokines stimulated high levels of NOS2 mRNA and NO production. However, prior induction of the HSR significantly inhibited NOS2 expression and NO synthesis. Cytokine-stimulated NOS2 promoter activity of transfected AKN-1 cells was decreased by 77%, but the HSR did not affect NOS2 enzyme activity in transduced AKN-1 cells.ConclusionsThese findings indicate that the HSR inhibits cytokine-induced NOS2 expression and NO synthesis in AKN-1 cells by preventing NOS2 promoter activation. Effects on NOS2 protein translation or stability were not observed. These data suggest that the HSR, which is expressed in the liver after trauma, shock, or ischemia-reperfusion, blocks NOS2 gene expression at the transcriptional level.