Effects of light cues on re-entrainment of the food-dominated peripheral clocks in mammals
Effects of light cues on re-entrainment of the food-dominated peripheral clocks in mammals
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DOI：
10.1016/j.gene.2008.04.010
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发表时间：
2008-08-01
期刊：
影响因子：
3.5
通讯作者：
Fu, Zhengwei
中科院分区：
文献类型：
--
作者：
Wu, Tao;Jin, Yuanxiang;Fu, Zhengwei
尽管与食物刺激相比，光/暗(LD)循环在外周时钟中是一个较弱的Zeitgeber，但光线索对外周时钟重新携带的影响是否能被主要食物线索的影响掩盖仍是未知的。在本研究中，限制饲养大鼠肝脏和心脏的核心时钟基因(BMal1、Cry1、PER1和Dec1)的昼夜节律模式不受个体反转7天的影响。相反，与单独颠倒喂食方案相比，颠倒喂食时间表和LD周期显著增强了外周时钟的重新携带。此外，仅LD逆转7d可反向调节肝脏和心脏中Cry1、PER1和Dec1的表达水平。此外，白天限食不仅导致四个被测时钟基因的相移速率不同，而且导致这两个外周时钟的重置过程中的相移方向发生逆转。此外，这些基因的重置序列在这两个外围时钟中也是不同的。这些观察表明，肝钟和心钟的机制是不同的，这可能会在SCN同步的外周系统中将它们区分开来。(C)2008爱思唯尔B.V.保留所有权利。
Although the light/dark (LD) cycle is a weak Zeitgeber in peripheral clocks compared with food stimuli, whether the effect of light cues on the re-entrainment of peripheral clocks can be masked by that of the dominating food cue remains unknown. In the present study, the individual reversal of LD cycle for 7 days could not obviously affect circadian patterns of core clock genes (Bmal1, Cry1, Per1, and Dec1) in the liver and heart of restricted-fed rats. In contrast, reversing the feeding schedule together with the LD cycle markedly enhanced the re-entrainment of peripheral clocks compared with reversal of the feeding regimen alone. In addition, LD reversal alone for 7 days contrarily regulated the expression levels of Cry1, Per1, and Dec1 in the liver and heart. Moreover, daytime restricted feeding not only induced different phase shift rates of the four examined clock genes but also led to reversed phase shift direction in their resetting processes in these two peripheral clocks. Furthermore, the resetting sequences of these genes were also disparate between these two peripheral clocks. These observations suggest that the mechanisms underlying the liver and heart clocks are distinct, which may distinguish them from each other in the SCN-synchronized peripheral system. (C) 2008 Elsevier B.V. All rights reserved.