Temperature compensation and temperature resetting of circadian rhythms in mammalian cultured fibroblasts
Temperature compensation and temperature resetting of circadian rhythms in mammalian cultured fibroblasts
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DOI：
10.1046/j.1365-2443.2003.00669.x
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发表时间：
2003-08-01
期刊：
影响因子：
2.1
通讯作者：
Nishida, E
中科院分区：
文献类型：
--
作者：
Tsuchiya, Y;Akashi, M;Nishida, E
背景：昼夜节律控制着许多生理过程。昼夜节律的特征之一是对温度不敏感，称为温度补偿。尽管这种温度不敏感特性主要在昼夜节律输出中被反复观察到，但温度对时钟基因表达的自调节反馈回路的影响，即节律产生机制，尚未得到充分研究。结果：我们首先发现，在33-42度的温度范围内，TPA （12- o -十四烷醇-13-乙酸酯）处理诱导的NIH3T3成纤维细胞中时钟基因表达的昼夜节律振荡是强烈的温度补偿。然后，我们发现42度的热处理能够触发NIH3T3细胞中时钟基因表达的昼夜节律振荡。与血清休克或TPA治疗不同，42度的热处理不会立即诱导mPer1 mRNA的表达，这表明存在几种不同的重置机制。结论：这是首次在哺乳动物培养细胞中证明时钟基因表达产生节律的核心反馈回路的温度补偿。外围的细胞可能将环境温度的变化作为重置的线索，因此整个生物体可能在黎明时分与光的重置机制合作而被快速地带走。
Background: Circadian rhythms control many physiological processes. One of characteristic properties of circadian rhythms is insensitivity to temperature, called temperature compensation. Although this temperature-insensitive property has repeatedly been observed mainly in circadian output rhythms, temperature effect on autoregulatory feedback loops of clock gene expression, the rhythm-generating mechanisms, has not been fully investigated.Results: We show first that the circadian oscillation of clock gene expression in NIH3T3 fibroblasts, which is induced by TPA (12-O-tetradecanoylphorbol-13-acetate) treatment, is strongly temperature-compensated over the temperature range of 33-42 degreesC. We then show that heat treatment at 42 degreesC is able to trigger circadian oscillation of clock gene expression in NIH3T3 cells. This 42 degreesC heat treatment, unlike serum shock or TPA treatment, did not induce immediate expression of mPer1 mRNA, suggesting the existence of several different resetting mechanisms.Conclusions: This is the first demonstration of temperature compensation of the rhythm-generating core feedback loops of clock gene expression in mammalian cultured cells. It is possible that cells in the periphery could sense the change of ambient temperature as a resetting cue and that the whole organism thus could be entrained rapidly at dawn, in cooperation with the resetting mechanism by light.