Mechanisms of circadian rhythm analyzed from transcription factor of mRNA in suprachiasmatic nucleus

从视交叉上核mRNA转录因子分析昼夜节律机制

• 批准号: 10670069
• 负责人: ISOBE Yoshiaki
• 金额: $ 2.11万
• 依托单位: Nagoya City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670069/
• 关键词: Suprachiasmatic nuclei; Arg-vasopressin; transcription; mRNA; c-fos; AP-1; RT-PCR; Vasopressin; messenger RNA; 5'-RACE; CRE(B); Urcadidn vthythm; saprachiasmatic nucleus

Arg-vasopressin (AVP) containing neurons in the suprachiasmatic nucleus (SCN) is one of the output paths of circadian information to other parts of the brain. The AVP contents show a free-running rhythm under the constant dim light, whose acrophase is developing during the early period of subjective day. It is useful to compare the AVP peptide levels with its coding mRNA in individual animals. In the present study, we analyzed the AVP mRNA levels by reverse transcription PCR (PT-PCR). We could detect the AVP mRNA levels extracted from two punches of SCN in one rat by using PT-PCR with specific primers. Effects of light or dark response to the SCN AVP mRNA were examined. The light responses to AVP peptide were more effective than to the dark. While, the AVP mRNA did not show an obvious change after transition to new lighting regime. The patterns of day-night variations in PCR product-intensity are similar with that analyzed by Northern blot. These day-night variations free-run until 21st day under the constant dim light. We find the differential responses in SCN (parvocellular AVP containing neuron) and supraoptic nucleus (magnocellular) against to GABA and corticosterone/dexamethasone. Photic stimulation from retina induces c-fos development in SCN. C-fos development couples with the phase responses and other indexes of circadian rhythm. These results suggest that the AVP peptide rhythm be checked not only by the control of synthesis, but also by the other systems. It is reasonable to speculate that the AVP coding gene might containing IEG(c-fos) binding site at the upstream of 5' promoter area. Although, the AVP coding DNA has no AP-1 binding site that was sequenced from the genome obtained from supraoptic nucleus or other brain area. We are searching the specific genome, which code AVP mRNA originating from the SCN.

视交叉上核(SCN)内含精氨酸加压素(AVP)的神经元是昼夜节律信息向大脑其他部位输出的途径之一。AVP含量在持续的暗光下表现为自由奔跑的节律，其顶相出现在主观白天的早期。比较单个动物的AVP多肽水平及其编码的mRNA是有用的。在本研究中，我们用逆转录聚合酶链式反应(RT-PCR)分析了AVP基因的表达水平。利用RT-PCR技术，可以检测到一只大鼠两针SCN中AVP基因的表达水平。观察光或暗反应对SCN-AVP基因表达的影响。对AVP多肽的光反应比暗反应更有效。而AVP的mRNA在过渡到新的光照条件后没有明显的变化。扩增产物强度的昼夜变化规律与Northern印迹分析结果相似。这些昼夜变化在持续昏暗的灯光下一直持续到第21天。我们发现小细胞AVP神经元(SCN)和视上核(大细胞)对GABA和皮质酮/地塞米松有不同的反应。来自视网膜的光刺激诱导SCN中c-fos的发展。C-fos的发育与昼夜节律的相位反应和其他指标相关联。这些结果表明，AVP多肽的节律不仅受合成的控制，还受其他系统的控制。推测AVP编码基因可能在5‘启动子上游含有IEG(c-fos)结合位点。然而，编码AVP的DNA没有从视上核或其他脑区获得的基因组测序的AP-1结合位点。我们正在寻找特定的基因组，它编码起源于SCN的AVP mRNA。

项目成果

Isobe,Y.: "Circadian rhythm of Arg-vasopressin contents in the suprachiasmatic nucleus in relation to conticosterone"Brain Res.. 800・1/2. 78-85 (1998)

Isobe，Y.：“视交叉上核中精氨酸加压素含量与conticosterone的昼夜节律”Brain Res.. 800・1/2（1998）。

Isobe, Y.: "Circadian rhythm of intrinsic locomotor activity : corticosterone and melatonin supresses running wheel activity"Photomed. Photobiol.. 21. 123-127 (1999)

Isobe，Y.：“内在运动活动的昼夜节律：皮质酮和褪黑激素抑制跑轮活动”拍摄。

Y. Isobe: "Subjective day and night differences of Arg-vasopressin mRNA in suprachiasmatic nuclei from individual rats estimated from RT-PCR"Jpn. J. Physiol. 48 (Suppl) S183. (1998)

Y. Isobe：“通过 RT-PCR 估计的个体大鼠视交叉上核中 Arg-加压素 mRNA 的主观昼夜差异”Jpn。

Y. Isobe and K. Nishihara: "Dexamethasone injection on different time of day at weaning may decide the onset of activity"International Symposium on Human Biometeorology, Aug. 31-Sept. 2, 1998, Fuji-Yoshidashi, Abstract. 63

Y. Isobe 和 K. Nishihara：“断奶时一天中不同时间注射地塞米松可能决定活动的开始”人类生物气象学国际研讨会，8 月 31 日至 9 月。

Y. Isobe: "Arg-vasopressin mRNA in individual suprachiasmatic nucleus (SCN) of rat estimated from RT-PCR was higher in subjective day than in night under the constant dim light."Neurosci. Res. 22 (Suppl.) S216. (1998)

Y. Isobe：“根据 RT-PCR 估计，大鼠个体视交叉上核 (SCN) 中的精氨酸加压素 mRNA 在持续昏暗的灯光下主观白天比夜间更高。”Neurosci。