Search for nutrients or drugs to improve metabolism by use of regulatory mechanism of ghrelin receptor gene transcription

利用ghrelin受体基因转录调控机制寻找改善新陈代谢的营养物质或药物

• 批准号: 14571070
• 负责人: KAJI Hidesuke
• 金额: $ 1.86万
• 依托单位: College of nursing Art & Science, Hyogo
• 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-14571070/
• 关键词: Ghrelin; Receptor; Gene transcription; HepG2 cell; Oleylethanoamide; Polyunsaturated fatty acid; Insulin sensitivity; Adiponectin; HeP G2細胞; 糖尿病; 肥満症; GH secretagogue受容体(GHS-R); HepG2細胞; 転写調節; 遺伝子; エンコサペンタエン酸EPA

A though patients with diabetes or obesity require severe restriction of calorie intake, it is usually hard to continue. Ghrelin, a ligand for growth hormone secretagogue receptor (GHS-R), was isolated from stomach and reported to play roles in stimulation of appetite as well as GH secretion. In addition, we have reported the role of ghrelin against insulin action in cultured hepatocytes In this study, we searched which nutrients or drugs might affect GHS-R gene transcription by luciferase assay system. The transcriptional activity (GHS-R/Luc) was located between -608 and -534p of 5'-flanking region of GHS-R gene, where AP_2 or bHLH was expected to bind. Gel shift assay demonstrated that fluorecent labeled DNA of this region specifically bound to nuclear proteins extracted from HepG_2 cells. Eicosa-pentaenoic acid (EPA) or troglitazone slightly inhibited GHS-R/Luc activity. These results suggest that EPA or troglitazone enhance insulin sensitivity, at least in part, by down-regulation of GHS-R. On the other hand, anorexic lipid, oleylethanolamide, caused a slight increase in GHS-R/Luc activity. We have experienced patients who had taken a certain diet tea and subsequently became diabetic. This diet tea inhibited glucose-induced insulin secretion from cultured pancreatic cells RIN-5F. However, this tea did not change GHS-R/Luc activity. Vitamin C,E, insulin, ghrelin, and leptin did not change GHS-R/Luc activity. As EPA caused down-regulation of GHS-R, we challenged polyunsaturated fatty acid (PUFA)-rich diet in young volunteer. The PUFA-rich diet caused an increase in HOMA-IR with a precedent elevation of plasma adiponectin levels. In conclusion, measurement of transcriptional activity of genes involved in metabolism is a useful way to search nutrients or drugs for prevention of diabetes or obesity.

虽然患有糖尿病或肥胖症患者需要严重限制卡路里摄入量，但通常很难继续。生长素蛋白是一种生长激素促分泌受体（GHS-R）的配体，从胃中分离出来，据报道在刺激食欲和GH分泌方面起着作用。此外，我们还报道了生长素素对胰岛素作用在这项研究中的作用在培养的肝细胞中，我们搜索了哪些营养物质或药物可能会影响荧光素酶测定系统的GHS-R基因转录。转录活性（GHS-R/LUC）位于GHS-R基因的5'Fanking区域的-608和-534p之间，其中AP_2或BHLH有望结合。凝胶转移测定法证明，该区域的荧光标记DNA专门与从HEPG_2细胞中提取的核蛋白结合。 eicosa-烯酸（EPA）或troglitazone略微抑制GHS-R/LUC活性。这些结果表明，EPA或Troglitazone至少部分通过下调GHS-R来增强胰岛素敏感性。另一方面，厌食的脂质，油甲醇酰胺导致GHS-R/LUC活性略有增加。我们经验丰富的患者，他们喝了一定的减肥茶，随后成为糖尿病患者。这种饮食茶抑制了葡萄糖诱导的胰岛素分泌RIN-5F。但是，这种茶没有改变GHS-R/LUC活性。维生素C，E，胰岛素，生长素和瘦素没有改变GHS-R/LUC活性。由于EPA导致GHS-R的下调，我们在年轻志愿者中挑战了多不饱和脂肪酸（PUFA） - 富含富含脂肪的脂肪酸。富含PUFA的饮食导致HOMA-IR的增加，血浆脂联素水平的先例升高。总之，测量参与代谢的基因的转录活性是搜索营养或药物以预防糖尿病或肥胖的有用方法。

项目成果

Sakurai T, iida K, Takahashi Y, Kaji H, Takakuwa S, Sumita R, et al.: "A novel heterozygous T51I mutation of growth hormone receptor is not associated with short stature"Growth Hormone & IGF Research. 12. 411-417 (2002)

Sakurai T、iida K、Takahashi Y、Kaji H、Takakuwa S、Sumita R 等人：“生长激素受体的新型杂合 T51I 突变与身材矮小无关”生长激素

Kishimoto M, Okimura Y, Nakata H, Kaji H, et al.: "The R271W mutant form of Pit-1 does not act as a dominant inhibitor of Pit-1 action to activate the promoters of GH and prolactin genes."European Journal of Endocrinology. 148. 619-625 (2003)

Kishimoto M、Okimura Y、Nakata H、Kaji H 等人：“Pit-1 的 R271W 突变体形式不能作为 Pit-1 作用的显性抑制剂来激活 GH 和催乳素基因的启动子。”《欧洲杂志》

Murata M, Okimura Y, Iida K, Matsumoto M, Kaji H et al.: "Ghrelin modulates the downstream molecules of insulin signaling in hepatoma cells"The Journal of Biological Chemistry. 277,7. 5667-5674 (2002)

Murata M、Okimura Y、Iida K、Matsumoto M、Kaji H 等人：“Ghrelin 调节肝癌细胞中胰岛素信号传导的下游分子”《生物化学杂志》。

Kaji H, Sakurai T, Iguchi G, Murata M, Yoshioka S et al.: "Adult growth hormone deficiency in Japan Results of investigation by questionnaire"Endocrine Journal. 49. 597-604 (2002)

Kaji H、Sakurai T、Iguchi G、Murata M、Yoshioka S 等：“日本成人生长激素缺乏症问卷调查结果”内分泌杂志。

Iida K, Okimura Y, Takahashi K, Kaji H et al.: "A variety of phenotype with R161Q germline mutation of the von Hippel-Lindau tumor suppressor gene in Japanese kindred."International Journal of Molecular Medicine. 13・3. 401-404 (2004)

Iida K、Okimura Y、Takahashi K、Kaji H 等：“日本亲属中 von Hippel-Lindau 肿瘤抑制基因的 R161Q 种系突变的多种表型。”国际分子医学杂志 13・3。 404（2004）