Functional CLOCK is not involved in the entrainment of peripheral clocks to the restricted feeding:: entrainable expression of mPer2 and BMAL1 mRNAs in the heart of Clock mutant mice on Jcl:ICR background
Functional CLOCK is not involved in the entrainment of peripheral clocks to the restricted feeding:: entrainable expression of mPer2 and BMAL1 mRNAs in the heart of Clock mutant mice on Jcl:ICR background
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DOI：
10.1016/s0006-291x(02)02427-0
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发表时间：
2002-10-25
影响因子：
3.1
通讯作者：
Ishida, N
中科院分区：
文献类型：
--
作者：
Oishi, K;Miyazaki, K;Ishida, N
哺乳动物的昼夜节律计时系统由大脑下丘脑的中央起搏器和大多数外周组织的阻尼振荡器组成。为了研究控制哺乳动物外周组织昼夜节律的机制，我们在 Jcl:ICR 背景下，在时间喂养限制下，检测了纯合 Clock 突变小鼠心脏中 mPer2、BMAL1、白蛋白 D 位点结合蛋白 (DBP) 和 Rev-erbalpha mRNA 的表达节律。出乎意料的是，限制喂养（RF）不仅改变了野生型小鼠的心脏，也改变了 Clock 突变小鼠心脏中 mPer2 和 BMAL1 mRNA 表达的昼夜节律阶段。此外，在 Clock 突变小鼠中，RF 显着增加了 mPer2 和 BMALI mRNA 的昼夜节律表达幅度。这些数据表明，将外设时钟夹带至 RF 不需要功能时钟。另一方面，Clock 突变小鼠中 DBP 和 Rev-erbalpha mRNA 的表达水平不仅在随意条件下而且在 RF 条件下均减弱。因此，尽管 REV-ERBα 已被确定为 BMALI 转录的主要调节因子，但 Rev-erbalpha 的节律表达似乎并不参与 RF 诱导的 BMALI mRNA 昼夜节律表达。因此，周围组织对射频的夹带机制似乎与视交叉上核中的中央时钟的夹带机制不同。 (C) 2002 年爱思唯尔科学（美国）。版权所有。
The mammalian circadian timing system consists of a central pacemaker in brain hypothalamus and damping oscillators in most peripheral tissues. To investigate the mechanism that controls circadian rhythms in the mammalian peripheral tissues, we examined the expression rhythm of mPer2, BMAL1, albumin D-site binding protein (DBP), and Rev-erbalpha mRNAs in the heart of homozygous Clock mutant mice on Jcl:ICR background under the temporal feeding restriction. Unexpectedly, the restricted feeding (RF) shifted the circadian phase of both mPer2 and BMAL1 mRNA expressions in the heart not only of wild-type mice but also of Clock mutant mice. Furthermore, in the Clock mutant mice, the amplitude of the circadian expression of mPer2 and BMALI mRNAs was dramatically increased by the RF. These data indicate that functional CLOCK is not required for an entrainment of peripheral clocks to RF. On the other hand, the expression levels of DBP and Rev-erbalpha mRNAs were blunted in Clock mutant mice not only under ad libitum but also under RF conditions. Thus, it seems that the rhythmic expression of Rev-erbalpha is not involved in the RF-induced circadian expression of BMALI mRNA, although REV-ERBalpha has been identified as a major regulator of BMALI transcription. Thus, the entraining mechanism of peripheral tissues to the RF seems to be different from that to the central clock in the suprachiasmatic nucleus. (C) 2002 Elsevier Science (USA). All rights reserved.