Study on physiological significance and mechanisms of a novel hypothalamic secretory protein(Fostering Joint International Research)

2019 Fiscal Year Final Research Report

• Project/Area Number: 15KK0259
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Morphology/Structure
• Research Institution: Hiroshima University
• Principal Investigator: Ukena Kazuyoshi 広島大学, 統合生命科学研究科(総), 教授 (10304370)
• Project Period (FY): 2016 – 2019
• Keywords: 視床下部 / 分泌性小タンパク質 / 摂食行動 / 脂肪蓄積 / de novo脂肪合成

Outline of Final Research Achievements

We recently identified a novel cDNA encoding a small secretory protein of 80 amino acid residues, termed neurosecretory protein GL (NPGL), from the chicken hypothalamus. Homologs of NPGL have been reported to be present in mammals. In this study, we investigated the function of NPGL in mice and rats. We found that NPGL mRNA is robustly expressed in the lateroposterior part of the arcuate nucleus in the hypothalamus. NPGL-immunoreactive fibers were observed in close anatomical contact with POMC neurons in the arcuate nucleus. Furthermore, NPGL increased food intake in mice. We also found that NPGL increased food intake and the mass of white adipose tissue (WAT) in rats. NPGL induced carbohydrate intake. NPGL mRNA expression was upregulated by fasting and low insulin levels. These results point to NPGL as a novel neuronal regulator that drives food intake and fat accumulation through de novo lipogenesis and acts to maintain a steady-state fat level in rodents.

Free Research Field

神経代謝調節学

Academic Significance and Societal Importance of the Research Achievements

我々は、他の研究グループが発見した既知の脳因子に関する研究ではなく、自らが発見した新規の脳因子NPGLに関する研究を推進し、極めて学術的独自性と創造性が高い成果を得ることができた。本来、脂肪蓄積は飢餓に備えた自己防御機構の一つである。脂肪組織でのde novo脂肪合成は糖代謝の改善等の報告が最近なされ始めており、NPGLによる脂肪組織のde novo脂肪合成制御は、我々ヒトの生活習慣病改善に役立つ可能性がある。