Laboratory of Neurometabolism, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8521, Japan.
Department of Neurophysiology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan.
Int J Mol Sci. 2021 Feb 20;22(4):2109. doi: 10.3390/ijms22042109.
Circadian desynchrony induced by a long period of irregular feeding leads to metabolic diseases, such as obesity and diabetes mellitus. The recently identified neurosecretory protein GL (NPGL) and neurosecretory protein GM (NPGM) are hypothalamic small proteins that stimulate food intake and fat accumulation in several animals. To clarify the mechanisms that evoke feeding behavior and induce energy metabolism at the appropriate times in accordance with a circadian rhythm, diurnal fluctuations in and mRNA expression were investigated in mice. Quantitative RT-PCR analysis revealed that the mRNAs of these two genes were highly expressed in the mediobasal hypothalamus during the active dark phase under ad libitum feeding. In mice restricted to 3 h of feeding during the inactive light phase, the mRNA level was augmented in the moment prior to the feeding period and the midnight peak of mRNA was attenuated. Moreover, the mRNA expression levels of clock genes, feeding regulatory neuropeptides, and lipid metabolic enzymes in the central and peripheral tissues were comparable to those of central and . These data suggest that and transcription fluctuates daily and likely mediates feeding behavior and/or energy metabolism at an appropriate time according to the meal timing.
由长时间不规则进食引起的昼夜节律失调会导致代谢疾病，如肥胖和糖尿病。最近发现的神经分泌蛋白 GL（NPGL）和神经分泌蛋白 GM（NPGM）是下丘脑的小蛋白，可刺激几种动物的摄食和脂肪积累。为了阐明根据昼夜节律引起摄食行为并诱导能量代谢的机制，研究了小鼠中 和 mRNA 表达的昼夜波动。定量 RT-PCR 分析显示，这两个基因的 mRNA 在自由进食下的活跃暗期的中脑基底下丘脑高度表达。在限制在非活动光期内进食 3 小时的小鼠中， mRNA 水平在进食期前增加，午夜 mRNA 峰值减弱。此外，中枢和外周组织中时钟基因、摄食调节神经肽和脂质代谢酶的 mRNA 表达水平与中枢 和 相似。这些数据表明 和 转录每天都有波动，可能根据进餐时间调节适当的摄食行为和/或能量代谢。
