Novel roles of ghrelin and nuromedin U as a modulator of circadian rhythmicity

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K00901
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Eating habits
• Research Institution: Kurume University
• Principal Investigator: Tajiri Yuji 久留米大学, 医学部, 准教授 (80469361)
• Co-Investigator(Kenkyū-buntansha): 山田 研太郎 久留米大学, 医学部, 教授 (10191305) ; 御船 弘治 久留米大学, 医学部, 准教授 (70174117)
• Co-Investigator(Renkei-kenkyūsha): KOJIMA MASAYASU 久留米大学, 分子生命科学研究所, 教授 (20202062)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 食行動異常 / 肥満モデルマウス / 高脂肪食負荷 / 時計遺伝子 / グレリン / ニューロメジン

Outline of Final Research Achievements

Circadian rhythmicity based on biological clock is entrained by food or exercise other than light stimulation. In obese model, such an entrainment is thought to be disrupted leading to abnormal feeding behavior. Rhythmicities of plasma ghrelin concentration and neuromedin U (NMU) expression in the hypothalamus are completely inversed in obesity model mice. In NMU knockout mice, voluntary exercise and exploring activity at the end of dark period were significantly decreased compared to those in WT mice. Furthermore, disrupted rhythms of clock genes were observed in obese model. Taken together, it was demonstrated that abnormal feeding behavior observed in obese model could be attributable to disrupted rhythm of either appetite regulating hormones or clock genes.

Free Research Field

糖尿病，肥満