Mechanisms for tissue specific expression and cell growth of 12/15-lipoxygenase

12/15-脂氧合酶的组织特异性表达和细胞生长机制

• 批准号: 10670134
• 负责人: YOSHIMOTO Tanihiro
• 金额: $ 2.05万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670134/
• 关键词: 12-Lipoxygenase; Athelosclerosis; Low density lipoprotein (LDL); Oxidized LDL; Scavenger receptor; Macrophage; 低比重リボタンパク質; スカベンジャ-受容体; アラキドン酸; リポキシゲナーゼ; cDNAクローニング

Lipoxygenase (LOX) incorporates a molecular oxygen into a specific carbon atom of unsaturated fatty acids. There are 5-, 8-, 12- and 15-LOXs in mammalian tissues according to the oxygenation site of arachidonic acid. Based upon the primary structures deduced from their cDNAs and enzymological properties, they are principally classified into 5-LOX and 12/15-LOX subfamilies. The 5-LOX catalyzes the first step in the generation of leukotrienes which have potent biological activities in the immediate hypersensitivity and allergy. There are number of isoforms of 12/15-LOXs : leukocyte, platelet and epidermis. Although the 12/15-LOXs have been shown to play roles in several systems such as atherosclerosis and neurotransmission, their pathophysiological functions are still subjects of investigation and discussion.There are a body of circumstantial evidences for a role of LOX in oxidative modification of low density lipoprotein (LDL). The aim of this study was to investigate the role of intrac … More ellular 12-LOX in the oxidative modification of LDL that leads to foam cell formation. We overexpressed 12-lipoxygenases in a macrophage-like cell line J774A.1 which originally did not show the detectable enzyme activity. When the 12-lipoxygenase-expressing cells were incubated with LDL in Dulbecco's modified Eagle medium at 37 ℃ for 12 h, LDL oxidation as determined by thiobarbituric acid reactive substance was markedly increased over the mock-transfected cells. Oxygenated products in the modified LDL were examined by high performance liquid chromatography before and after alkaline hydrolysis. Most of the oxygenated derivatives were of an esterified form, and the major product was identified to be 13S-hydroxyoctadeca-9Z, 11E-dienoic acid. These results clearly demonstrated that esterified fatty acids in LDL were oxygenated by the 12-lipoxygenases expressed in the J774A.1 cells. Furthermore, the oxidized LDL generated by intracellular 12-lipoxygenases was recognized by a scavenger receptor as assessed by macrophage degradation assay. Less

脂氧合酶（LOX）将分子氧结合到不饱和脂肪酸的特定碳原子中。根据花生四烯酸的加氧位点不同，哺乳动物组织中存在5-、8-、12-和15-LOX。根据其cDNA序列的一级结构和酶学性质，主要分为5-LOX和12/15-LOX两个亚家族。5-LOX催化产生白三烯的第一步，白三烯在速发型超敏反应和变态反应中具有强大的生物活性。存在许多12/15-LOX的同种型：白细胞、血小板和表皮。尽管12/15-LOX在动脉粥样硬化和神经传递等多种系统中发挥作用，但其病理生理功能仍是研究和讨论的主题，有大量间接证据表明LOX在低密度脂蛋白（LDL）的氧化修饰中发挥作用。本研究的目的是探讨intrac ...更多信息 细胞12-LOX在LDL的氧化修饰中导致泡沫细胞形成。我们在巨噬细胞样细胞系J774A.1中过表达12-脂氧合酶，该细胞系最初没有显示出可检测的酶活性。当表达12-脂氧合酶的细胞与LDL在Dulbecco改良的Eagle培养基中于37 ℃孵育12 h时，用硫代巴比妥酸反应物质测定的LDL氧化比模拟转染的细胞显著增加。用高效液相色谱法检测了改性LDL碱水解前后的氧化产物。大多数含氧衍生物为酯化形式，主要产物经鉴定为13 S-羟基十八碳-9Z，11 E-二烯酸。这些结果清楚地表明，LDL中的酯化脂肪酸被J774A.1细胞中表达的12-脂氧合酶氧化。此外，通过巨噬细胞降解试验评估，细胞内12-脂氧合酶产生的氧化LDL被清道夫受体识别。少

项目成果

Takahiro Kinoshita, T.et al.: "Growth stimulation and induction of epidermal growth factor receptor by overexpression of cyclooxygenases 1 and 2 in human colon carcinoma cells" Biochimica et Biophysica Acta. (印刷中).

Takahiro Kinoshita, T. 等人：“通过在人结肠癌细胞中过表达环氧合酶 1 和 2 来刺激和诱导表皮生长因子受体”Biochimica et Biophysical Acta（出版中）。

T. Sakashita, et al.: "Essential involvement of 12-lipoxygenase in regiospecific and stereospecific oxidation of low density lipoprotein by macrophages"Eru. J. Biochem.. 265. 825-831 (1999)

T. Sakashita 等人：“12-脂氧合酶在巨噬细胞对低密度脂蛋白的区域特异性和立体特异性氧化中的重要参与”Eru。

T. Sakashita, et al.: "Essential involvement of 12-lipoxygenase in regiospecific and stereospecific oxidation of flow density lipoprotein by macrophages"Eur. J. Biochem.. 265. 825-831 (1999)

T. Sakashita 等人：“12-脂氧合酶在巨噬细胞对流密度脂蛋白的区域特异性和立体特异性氧化中的重要参与”Eur。

Y. Takahashi, et al.: "Activation of matrix metalloproteinase-2 in human breast cancer cells overexpressing cyclooxygenase-1 or -2"FEBS Lett.. 460. 145-148 (1999)

Y. Takahashi 等人：“过表达环氧合酶-1 或 -2 的人乳腺癌细胞中基质金属蛋白酶-2 的激活”FEBS Lett.. 460. 145-148 (1999)

T. Kinoshita, et al.: "Growth stimulation and induction of epidermal growth factor receptor by overexpression of cyclooxygenases 1 and 2 in human colon carcinoma cells"Biochim. Biophys. Acta.. 1438. 120-130 (1999)

T. Kinoshita 等人：“通过在人结肠癌细胞中过表达环氧合酶 1 和 2 来刺激和诱导表皮生长因子受体”Biochim。