New function of NADPH-P450 reductase(NPR) : Regulation of hypoxia-response genes by NPR.

NADPH-P450还原酶(NPR)的新功能：NPR对缺氧反应基因的调节。

• 批准号: 14572095
• 负责人: IMAOKA Susumu
• 金额: $ 2.11万
• 依托单位: Kwansei Gakuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14572095/
• 关键词: hypoxia; NADPH-P450 reductase; erythropoietin; VEGF; bisphenol A; HSP90; HIF-1α; 低酸素; 活性酸素

Hypoxia is a common feature of many cancers. It contributes local and systemic tumor progression. Hypoxia is also an important factor in myocardial infarction. In hypoxic condition, hypoxia-inducible factor(HIF-1α) is stabilized and transcriptionally regulates hypoxia-response genes such as erythropoietin(EPO) and VEGF, by recognition of hypoxia response element(HRE). We found that NADPH-P450 reductase(NPR) was necessary for stabilization of HIF-1α. When NPR expression in Hep3B cells was suppressed by knockdown, HIF-1α protein was degraded. We also found that bisphenol A(BpA), an endocrine-disrupting chemical, degraded HIF-1α under hypoxia. BpA didn't interact with NPR but did with a chaperon protein, HSP90. HSP90 stabilized HEF-1α under hypoxia and BpA dissociated HSP-90 from HIF-1α. HIF-1α is known to be degraded by ubiquitination and proteasome pathway BpA degraded HIF-1α even in the presence of inhibitors for ubiquitination and proteasome degradation. These results suggested that BpA degraded HIF-1α via a currently unknown pathway. Furthermore, we searched factors which interact with NPR using yeast two-hybrid system. Some candidates were obtained and seem to contribute to the redox regulation of the cells. Further analysis for biological functions of these factors is necessary.

缺氧是许多癌症的共同特征。它有助于局部和全身肿瘤进展。缺氧也是心肌梗死的重要因素。低氧诱导因子（hypoxia-inducible factor，HIF-1α）在低氧条件下通过识别低氧反应元件（hypoxiaresponseelement，HRE）而稳定并转录调控促红细胞生成素（erythropoietin，EPO）和血管内皮生长因子（VEGF）等低氧反应基因。我们发现NADPH-P450还原酶（NPR）是稳定HIF-1α所必需的。当NPR表达被敲低后，HIF-1α蛋白被降解。我们还发现，双酚A（BpA），一种内分泌干扰化学品，在缺氧条件下降解HIF-1α。BpA不与NPR相互作用，但与伴侣蛋白HSP 90相互作用。HSP-90在缺氧条件下稳定HEF-1α，BpA使HSP-90与HIF-1α解离。已知HIF-1α通过泛素化和蛋白酶体途径降解，即使在存在泛素化和蛋白酶体降解抑制剂的情况下，BpA也降解HIF-1α。这些结果表明BpA通过目前未知的途径降解HIF-1α。并利用酵母双杂交系统，寻找与NPR相互作用的因子。获得了一些候选物，并且似乎有助于细胞的氧化还原调节。对这些因子的生物学功能进行进一步的分析是必要的。

项目成果

M.Osada, S.Imaoka, T.Sugimoto et al.: "NADPH-cytochrome P-450 reductase in the plasma membrane modulates the activation of hypoxia-inducible factor 1."Journal of Biological Chemistry. 277(26). 23367-23373 (2002)

M.Osada、S.Imaoka、T.Sugimoto 等人：“质膜中的 NADPH-细胞色素 P-450 还原酶调节缺氧诱导因子 1 的激活。”生物化学杂志。

Yamaguchi Y., Kirita S., Hasegawa H., Aoyama J., Imaoka S.et al.: "Contribution of CYP4A8 to the formation of 20-hydroxyeicosatetraenoic acid from arachidonic acid in rat kidney"Drug Metabol. Pharmacokin.. 17(2). 109-116 (2002)

Yamaguchi Y.、Kirita S.、Hasekawa H.、Aoyama J.、Imaoka S.et al.：“CYP4A8 对大鼠肾脏中花生四烯酸形成 20-羟基二十碳四烯酸的贡献”药物代谢。

A.Kinoshita, H.Wanibuchi, S.Imaoka et al.: "Formation of 8-hydroxydeoxyguanosine and cell-cycle arrest in the rat liver via generation of oxidative stress by phenobarbital"Carcinogenesis. 23(2). 341-349 (2002)

A.Kinoshita、H.Wanibuchi、S.Imaoka 等人：“通过苯巴比妥产生氧化应激，在大鼠肝脏中形成 8-羟基脱氧鸟苷和细胞周期停滞”致癌作用。

M.Osada, S.Imaoka, T.Sugimoto, T.Hiroi, Y.Funae: "NADPH-cytochrome P-450 reductase in the plasma membrane modulates the activation of hypoxia-inducible factor 1."J.Biol.Chem.. 277(26). 23367-23373 (2002)

M.Osada、S.Imaoka、T.Sugimoto、T.Hiroi、Y.Funae：“质膜中的 NADPH-细胞色素 P-450 还原酶调节缺氧诱导因子 1 的激活。”J.Biol.Chem..

Kamada T., Chow T., Hiroi T., Imaoka S., Morimoto K.et al.: "Metabolism of seleginine hydrochloride, a selective monoamine B-type inhibitor, in human liver microsomes"Drug Metabol. Pharmacokin.. 17(3). 199-206 (2002)

Kamada T.、Chow T.、Hiroi T.、Imaoka S.、Morimoto K.et al.：“选择性单胺 B 型抑制剂盐酸司来吉宁在人肝微粒体中的代谢”药物代谢。