A Circadian Clock in HaCaT Keratinocytes
A Circadian Clock in HaCaT Keratinocytes
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DOI：
10.1038/jid.2010.315
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发表时间：
2011-02-01
影响因子：
6.5
通讯作者：
Kramer, Achim
中科院分区：
文献类型：
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作者：
Spoerl, Florian;Schellenberg, Katja;Kramer, Achim
为了预测每天的环境变化，大多数生物体发展了内源性计时系统，即所谓的昼夜节律（类似于24小时）时钟。生物钟存在于大多数外周组织中，并控制着各种各样的细胞、代谢和生理过程。最近的研究表明，白天依赖性的变化，表皮功能，如屏障恢复和pH稳态。然而，表皮角质形成细胞中的局部昼夜节律钟尚未报道，因此昼夜节律系统和表皮生理学之间的分子联系仍然难以捉摸。在这项研究中，我们描述了一个功能细胞自主的昼夜节律钟在人类成人低钙温度（HaCaT）角质形成细胞。使用活细胞生物发光成像和mRNA表达的时间序列，我们显示出强大的昼夜节律的同步HaCaT角质形成细胞的典型时钟基因的转录。遗传和药理学扰动实验以及时钟基因节律之间的相位关系证实了HaCaT角质形成细胞时钟的分子组成与其他外周时钟非常相似。此外，温度被确定为一个有效的时间线索（Zeitgeber）的表皮振荡器。温度周期夹带HaCaT角质形成细胞，导致识别参与表皮生理学如胆固醇稳态和分化的几个基因的节律表达。因此，我们目前HaCaT角质形成细胞作为一个很好的模型，研究角质形成细胞生理调节的生物钟在一个简单而强大的体外系统。
To anticipate daily environmental changes, most organisms developed endogenous timing systems, the so-called circadian (similar to 24 hours) clocks. Circadian clocks exist in most peripheral tissues and govern a huge variety of cellular, metabolic, and physiological processes. Recent studies have suggested daytime-dependent variations in epidermal functions such as barrier recovery and pH homeostasis. However, a local circadian clock in epidermal keratinocytes has not been reported yet, and as such the molecular link between the circadian system and epidermal physiology remains elusive. In this study we describe a functional cell autonomous circadian clock in human adult low calcium temperature (HaCaT) keratinocytes. Using live-cell bioluminescence imaging and mRNA expression time series, we show robust circadian transcription of canonical clock genes in synchronized HaCaT keratinocytes. Genetic and pharmacological perturbation experiments as well as the phase relations between clock gene rhythms confirm that the molecular makeup of the HaCaT keratinocyte clock is very similar to that of other peripheral clocks. Furthermore, temperature was identified to be a potent time cue (Zeitgeber) for the epidermal oscillator. Temperature cycles entrain HaCaT keratinocytes, leading to the identification of rhythmic expression of several genes involved in epidermal physiology such as cholesterol homeostasis and differentiation. Thus, we present HaCaT keratinocytes as an excellent model to study the regulation of keratinocyte physiology by the circadian clock in a simple yet robust in vitro system.