Analysis of prostaglandin E2 synthases

前列腺素 E2 合酶分析

• 批准号: 12557213
• 负责人: KUDO Ichiro
• 金额: $ 8.06万
• 依托单位: Showa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12557213/
• 关键词: PGE_2; PGE_2 synthase; Cyclooxygenase; Hsp90; Colon tumors; Arachidonic acid; Inflamamtory

The aims of this study are to perform biochemical characterization of two prostaglandin E2 synthases (PGESs) and to clarify their physilogical and pathological functions.Cytosolic PGES (cPGES) is a cytosolic 23-kDa protein that is expressed ubiuitously and constitutively in a wide variety of cells and tissues. This enzyme is identical to p23, which is associated with the molecular chaperone Hsp9O. cPGES is functionally coupled with cyclooxygenase (COX)-1 to promote immediate PGE2 production. The Hsp9O-bound cPGES is an active form, and the formation of this complex is facilitated immediately after cell activation with A23187. Hsp9O inhibitors, such as geldanamycin, as well as glucocorticoid prevents the formation of the Hsp9O/cPGES complex, thereby attenuating the PGE2biosynthetic response. After cell activation, cPGES translocates from the cytosol to the endoplasmic reticulum, where it is colocalized with COX-1. cPGES undergoes phosphorylation, although its biological significance rem … More ains elusive. Finally, there are at least four alternative spliced variants of cPGES, each of which exhibited distinct tissue distribution and showed different kinetic parameters (Km and Vmax) for the substrate PGH2.Microsomal PGES (mPGES) is a perinuclear 18-kDa protein that is strongly induced in various cells and tissues following proinflamamtory stimuli. This enzyme belongs to the class microsomal glutathione-Stransferase family. mPGES is functionally coupled with COX-2 in marked preference to COX-1 to promote delayed PGE2 production and primed immediate PGE2 production. Cotransfection of COX-2 and mPGES into HEK293 cells results in aggressive growth and morphological change in culture. Furthermore, the cotransfectants grow in soft agar to form large colonies and are tumorigenic in nude mice. A colon carcinoma cell line (HCA-7), the growth of which depends on COX-2, also expresses mPGES, where both enzymes are colocalized in the perinuclear reagion. Immunohistochemical staining of human tissues reveal that both COX-2 and mPGES are expressed in colon tumors, rheumatoid arthritis, ischemic hearts, C-type hepatitis, and brain endothelial cells. Less

本研究的目的是对两种前列腺素 E2 合酶 (PGES) 进行生化表征，并阐明其生理和病理功能。 胞质 PGES (cPGES) 是一种胞质 23-kDa 蛋白，在多种细胞和组织中普遍且组成型表达。该酶与 p23 相同，p23 与分子伴侣 Hsp9O 相关。 cPGES 与环氧合酶 (COX)-1 功能性偶联，可促进 PGE2 立即产生。 Hsp9O 结合的 cPGES 是一种活性形式，在用 A23187 激活细胞后立即促进该复合物的形成。 Hsp9O 抑制剂（例如格尔德霉素）以及糖皮质激素可阻止 Hsp9O/cPGES 复合物的形成，从而减弱 PGE2 生物合成反应。细胞激活后，cPGES 从细胞质转移到内质网，与 COX-1 共定位。 cPGES 会发生磷酸化，尽管其生物学意义尚不清楚。最后，cPGES 至少有四种可变剪接变体，每种变体都表现出不同的组织分布，并显示底物 PGH2 的不同动力学参数（Km 和 Vmax）。微粒体 PGES (mPGES) 是一种核周 18-kDa 蛋白，在促炎刺激后在各种细胞和组织中被强烈诱导。该酶属于微粒体谷胱甘肽-S转移酶家族。 mPGES 在功能上与 COX-2 结合，明显优于 COX-1，以促进延迟的 PGE2 产生并启动立即的 PGE2 产生。 COX-2 和 mPGES 共转染 HEK293 细胞会导致培养物的快速生长和形态变化。此外，共转染子在软琼脂中生长形成大集落，并且在裸鼠中具有致瘤性。结肠癌细胞系 (HCA-7) 的生长依赖于 COX-2，也表达 mPGES，其中两种酶共定位于核周区域。人体组织的免疫组织化学染色显示，COX-2和mPGES在结肠肿瘤、类风湿性关节炎、缺血性心脏、C型肝炎和脑内皮细胞中均有表达。较少的

项目成果

H. Kuwata, S. Yamamoto, Y. Miyazald, S. Shimbara, Y. Nakatani, H. Suzuki, N. Ueda, S. Yamamoto, M. Murakami, and I. Kudo: "Studies on a mechanism by which cytosolic phospholipase.A, regulates the expression and function of type IIA secretory phospholipase

H. Kuwata、S. Yamamoto、Y. Miyazald、S. Shimbara、Y. Nakatani、H. Suzuki、N. Ueda、S. Yamamoto、M. Murakami 和 I. Kudo：“胞质磷脂酶的机制研究

Ueno, N. et al.: "Coupling between cyclooxygenase, terminal prostanoid synthase, and phospholipase A_2"J.Biol.Chem.. 276. 34918-34927 (2001)

Ueno，N.等：“环氧合酶、末端前列腺素合酶和磷脂酶A_2之间的偶联”J.Biol.Chem.. 276. 34918-34927 (2001)

Y. Nakatani, T. Tanioka, S. Sunaga, M. Murakami, and I. Kudo: "IdenMcation of a cellular protein that functionally interacts with the C2 domain of cytosolic phospholipase A2α."J. BioL Chem. 275. 1161-1168 (2000)

Y. Nakatani、T. Tanioka、S. Sunaga、M. Murakami 和 I. Kudo：“与胞质磷脂酶 A2α 的 C2 结构域功能性相互作用的细胞蛋白的鉴定。”J. BioL Chem。 (2000)

中谷良人, 工藤一郎: "PLA2,COX-2,各種PG合成酵素と抗炎症戦略"Pharma Medica. 19. 13-18 (2001)

Yoshito Nakatani、Ichiro Kudo：“PLA2、COX-2、各种 PG 合酶和抗炎策略”Pharma Medica。19. 13-18 (2001)

S. Bezzine, R. S. Koduri, E. Valentin, M. Mnrakami, I. Kudo, F. Ghomashchi, M. Sadilek, O. Lambeau, and M. H. Gelb: "Exogenously added human group X secreted phospholipase A2 but not group IB, IIA, and V enzymes efficiently release arachi donic acid froni

S. Bezzine、R. S. Koduri、E. Valentin、M. Mnrakami、I. Kudo、F. Ghomashchi、M. Sadilek、O. Lambeau 和 M. H. Gelb：“外源添加的人类 X 组分泌磷脂酶 A2，但不分泌 IB、IIA 组