The gut-brain peptide neuromedin U is involved in the mammalian circadian oscillator system
The gut-brain peptide neuromedin U is involved in the mammalian circadian oscillator system
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DOI：
10.1016/j.bbrc.2004.04.014
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发表时间：
2004-05-21
影响因子：
3.1
通讯作者：
Kojima, M
中科院分区：
文献类型：
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作者：
Nakahara, K;Hanada, R;Kojima, M
免疫组织化学分析显示，在主昼夜节律振荡器所在地视交叉上核（SCN）中存在一种肠脑肽，神经质蛋白U （NMU）。NMU mRNA的表达具有昼夜节律性，在CT4-8 h时在SCN中达到峰值。两种NMU结合受体（NMU- r1和NMU- r2）也在SCN中表达，但它们的相位角不同。脑室内注射（ICV） NMU诱导SCN细胞中Fos蛋白的表达，并引起昼夜运动活动节律的相依赖相移。相移的大小与剂量有关。这种nmu诱导的相移是非光型的。定量逆转录聚合酶链反应（RT-PCR）分析显示，SCN中c-fos、NGFI-A、NGFI-B和JunB等早期基因的表达增加。此外，ICV注射NMU增加了SCN中Per]的表达，但没有增加Per2的表达。这些结果表明，NMU可能在SCN中发挥自分泌或旁分泌作用，在昼夜节律振荡器中发挥重要作用。(C) 2004爱思唯尔公司版权所有。
Immunohistochemical analysis revealed the presence of a gut-brain peptide, neuromedin U (NMU), in the suprachiasmatic nucleus (SCN), which is the site of the master circadian oscillator. The expression of NMU mRNA exhibited a circadian rhythm, with the peak expression in the SCN occurring at CT4-8 h. The two NMU-binding receptors (NMU-R1 and NMU-R2) were also expressed in the SCN, but their phase angles were different. Intracerebroventricular injection (ICV) of NMU induced the expression of Fos protein in the SCN cells and caused a phase-dependent phase shift of the circadian locomotor activity rhythm. The magnitude of the phase shift was dose dependent. This NMU-induced phase shift was of the nonphotic type. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed increases in the expression in the SCN of immediate early genes, such as c-fos, NGFI-A, NGFI-B, and JunB. Furthermore, ICV injection of NMU increased the expression of Per], but not Per2, in the SCN. These results indicate that NMU may play some important role in the circadian oscillator by exerting an autocrine or paracrine action in the SCN. (C) 2004 Elsevier Inc. All rights reserved.