The new approach to the diabetogenic mechanism and the new therapy : The disturbance of insulin secretion by oxidized lipoproteins and its relief

糖尿病发生机制的新途径和新疗法：氧化脂蛋白对胰岛素分泌的干扰及其缓解

• 批准号: 15590959
• 负责人: OIKAWA Shinichi
• 金额: $ 2.18万
• 依托单位: Nippon Medical School
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15590959/
• 关键词: beta cells; insulin secretion; LDL receptor; scavenger receptor; oxidized LDL; acetulated LDL

We have studied whether low-density lipoprotein(LDL) affected on the insulin secretion of pancreatic beta cells. We speculated that the modified LDLs affected on beta cell function after the uptake of LDL through lipoprotein receptor, so at first we checked that the lipoprotein receptors were found in the pancreatic beta cells. The immunostaining of the beta cells was performed with anti-rat insulin antibody, anti-LDL receptor(LDL-R) antibody, and anti-scavenger receptor antibodies (CD36 and SRB1). The positively stained cells with anti-insulin antibody were also stained with anti-LDL-R antibody, anti-CD36 antibody and anti-SRB1 antibody. These results indicated that the beta cells had not only LDL receptor, which was ubiquitously expressed, but also scavenger receptors concomitantly. In order to study how mRNA of each receptor was expressed in beta cells, we prepared the total RNA from rat liver, kidney, islets of pancreas and Hit-T15 cells, which were the cell line derived from hamst … More er pancreatic beta cells. The rat liver expressed each mRNA of LDL-R, SRB1, and CD36. The rat kidney had both receptors mRNA of LDL-R and SRB1, but not CD36 mRNA, which had already been reported in anywhere. In the rat islets and Hit-T15 cells each mRNA of LDL-R, SRB1 and CD36 was expressed as same as liver. Therefore it was suggested that lipoproteins would be up taken through the receptors and affect on insulin secretion. In order to check the lipoprotein uptake, Hit-T15 cells were cultured with DiI-labeled native LDL (nLDL), oxidized LDL (oxLDL), and acetylated LDL (AcLDL). Hit-T15 cells were clearly marked under the fluorescence microscopy, which suggested that every LDLs were internalized into the cells. These results suggested that each LDL was uptaken through each receptor. Next we checked the insulin secretion in Hit-T15 cells cultured with each LDL. OxLDL (25 or 50 μg/ml) were added into the culture of Hit-T15 cells for 24 or 48 hours. The glucose concentrations of the medium were set at 1,3,and 5mg/ml. The insulin secretion and the intracellular insulin contents in the culture with oxLDL were disturbed in the dose and time dependent manner. The expression of insulin gene was significantly decreased in the oxLDL addition. These results were not found in nLDL and AcLDL added culture. These changes of the insulin metabolism in Hit-T15 cells were caused by oxLDL and not by AcLDL. As conclusions oxLDL affected on the beta cells disturbing insulin gene espression and decreasing the intracellular insulin contents and the insulin seceretion. These have been published in Biochim Biophys A - Mol Cell Biol L(1687:173-180,2005). Less

我们研究了低密度脂蛋白（LDL）对胰岛β细胞胰岛素分泌的影响。我们推测修饰的LDL通过脂蛋白受体摄取LDL后影响β细胞功能，因此首先我们检查了在胰腺β细胞中发现的脂蛋白受体。用抗大鼠胰岛素抗体、抗LDL受体（LDL-R）抗体和抗清道夫受体抗体（CD 36和SRB 1）对β细胞进行免疫染色。抗胰岛素抗体染色阳性的细胞同时用抗LDL-R抗体、抗CD 36抗体和抗SRB 1抗体染色。这些结果表明，β细胞不仅具有广泛表达的LDL受体，而且还伴随有清道夫受体。为了研究每种受体的mRNA在β细胞中的表达，我们制备了来自大鼠肝脏、肾脏、胰岛和Hit-T15细胞的总RNA，Hit-T15细胞是来自仓鼠的细胞系 ...更多信息 胰腺β细胞大鼠肝脏表达LDL-R、SRB 1和CD 36的每种mRNA。大鼠肾组织中有LDL-R和SRB 1两种受体mRNA，但无CD 36 mRNA的表达。在大鼠胰岛和Hit-T15细胞中，LDL-R、SRB 1和CD 36的mRNA表达与肝脏相同。提示脂蛋白可通过受体摄取，影响胰岛素分泌。为了检查脂蛋白摄取，Hit-T15细胞与DiI标记的天然LDL（nLDL）、氧化LDL（oxLDL）和乙酰化LDL（AcLDL）一起培养。在荧光显微镜下，Hit-T15细胞标记清晰，表明各种LDL均被内化到细胞内。这些结果表明，每种LDL通过每种受体被摄取。接下来，我们检查了与每种LDL一起培养的Hit-T15细胞中的胰岛素分泌。将OxLDL（25或50 μg/ml）加入到Hit-T15细胞培养物中24或48小时。培养基的葡萄糖浓度设定为1、3和5 mg/ml。oxLDL对胰岛素分泌和细胞内胰岛素含量的影响呈剂量和时间依赖性。胰岛素基因的表达在oxLDL的加入下显著降低。而在nLDL和AcLDL添加培养中则没有发现这些结果。Hit-T15细胞胰岛素代谢的这些变化是由oxLDL引起的，而不是由AcLDL引起的。结论oxLDL可影响胰岛β细胞胰岛素基因表达，降低细胞内胰岛素含量和胰岛素分泌。这些已经发表在BiochimBiophysA-MolCellBiolL（1687：173- 180，2005）中.少

项目成果

Isohumulones, bitter acids derived from hops, activate both peroxisome prolife rator-activated receptor aand g and reduce insulin resistance

异葎草酮（源自啤酒花的苦酸）可激活过氧化物酶体增殖物激活受体 a 和 g，并降低胰岛素抵抗

• 发表时间: 2004
• 期刊: F Biol Chem 279・32
• 作者: Yajima H;Ikeshima E;Shiraki M;Kanaya T;Fujiwara D;Odai H;Tsuboyama-Kasaoka N;Ezaki A;Oikawa S;Kondo K
• 通讯作者: Kondo K

Obana N, Takagi S, Kinouchi Y, Tokita Y, Sekikawa A, Takahashi S, Hiwatashi N, Oikawa S, Shimosegawa T: "Telomere shortening of peripheral blood mononuclear cells in coronary disease patients with metabolic disorders"Int Med. 42・2. 150-153 (2003)

Obana N、Takagi S、Kinouchi Y、Tokita Y、Sekikawa A、Takahashi S、Hiwatashi N、Oikawa S、Shimosekawa T：“伴有代谢紊乱的冠心病患者外周血单核细胞的端粒缩短”Int Med 42・2。 150-153 (2003)

Matsuzawa Y, Kita T, Mabuchi H, Matsuzaki M, Nakaya N, Oikawa S, Saito Y, Sasaki J, Shimamoto K, Itakura H, The J-LIT Study Group: "Sustained reduction of serum choleseterol in low-dose 6-year simvastatin treatment with minimum side effects in 51,321 Japa

Matsuzawa Y、Kita T、Mabuchi H、Matsuzaki M、Nakaya N、Oikawa S、Saito Y、Sasaki J、Shimamoto K、Itakura H、J-LIT 研究组：“低剂量 6 年持续降低血清胆固醇

Oak J-H., Nakagawa K., Oikawa S, Miyazawa T: "Amadori-glycated phosphatidylethanolamine induces angiogenic differentiations in cultured human umbilical vein endothelial cells"FEBS Letters. 555・2. 419-423 (2003)

Oak J-H.、Nakakawa K.、Oikawa S、Miyazawa T：“Amadori 糖化磷脂酰乙醇胺诱导培养的人脐静脉内皮细胞的血管生成分化”FEBS Letters 555·2（2003）。

Amadori-glycated phosphatidylethanolamine induces angiogenic differentiation in cultured human umbilical vein endothelial cells

阿马多里糖化磷脂酰乙醇胺诱导培养的人脐静脉内皮细胞的血管生成分化

• 发表时间: 2003
• 期刊: FEBS Letters 555-2
• 作者: Oak J-H.;Nakagawa K.;Oikawa S;Miyazawa T
• 通讯作者: Miyazawa T