Hypoxia induces type II NOS gene expression in pulmonary artery endothelial cells via HIF-1
Hypoxia induces type II NOS gene expression in pulmonary artery endothelial cells via HIF-1
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DOI：
10.1152/ajplung.1998.274.2.l212
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发表时间：
1998-02-01
影响因子：
4.9
通讯作者：
Johns, RA
中科院分区：
文献类型：
--
作者：
Palmer, LA;Semenza, GL;Johns, RA
在肺动脉高压慢性缺氧模型中，II型一氧化氮合酶（NOS）在肺血管中的表达上调。原位杂交分析显示，II型NOS RNA在肺内皮细胞和血管平滑肌中表达增加。目前的研究探讨了缺氧诱导因子(HIF)-1在肺动脉内皮细胞缺氧反应中调节II型NOS基因表达的作用。Northern blot分析表明，体内和体外缺氧时HIF-1 α增加两倍，但HIF-1 β RNA没有增加。电泳迁移率转移试验表明，内皮细胞在缺氧条件下可诱导特异性DNA结合活性。使用针对HIF-1 α和HIF-1 β的抗体鉴定该DNA结合复合物为HIF-1。与非缺氧对照相比，内皮细胞瞬时转染导致II型NOS启动子活性在缺氧条件下增加2.7倍。HIF-1位点的突变或缺失消除了对缺氧的反应。这些结果表明HIF-1在缺氧条件下对肺内皮细胞II型NOS基因转录的调控至关重要。
Type II nitric oxide synthase (NOS) is upregulated in the pulmonary vasculature in a chronic hypoxia model of pulmonary hypertension. In situ hybridization analysis demonstrates that type II NOS RNA is increased in the endothelium as well as in the vascular smooth muscle in the lung. The current studies examine the role of hypoxia-inducible factor (HIF)-1 in regulating type II NOS gene expression in response to hypoxia in pulmonary artery endothelial cells. Northern blot analyses demonstrate a twofold increase in HIF-1 alpha but not in HIF-1 beta RNA with hypoxia in vivo and in vitro. Electrophoretic mobility shift assays show the induction of specific DNA binding activity when endothelial cells were subjected to hypoxia. This DNA binding complex was identified as HIF-1 using antibodies directed against HIF-1 alpha and HIF-1 beta. Transient transfection of endothelial cells resulted in a 2.7-fold increase in type II NOS promoter activity in response to hypoxia compared with nonhypoxic controls. Mutation or deletion of the HIF-1 site eliminated the response to hypoxia. These results demonstrate that HIF-1 is essential for the hypoxic regulation of type II NOS gene transcription in pulmonary endothelium.