Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli, 80078 Naples, Italy.
Department of Medical Translational Sciences, University of Naples Federico II, 80138 Napoli, Italy.
J Mol Biol. 2015 May 22;427(10):1887-902. doi: 10.1016/j.jmb.2015.03.007. Epub 2015 Mar 18.
Ultradian oscillators are cyclically expressed genes with a period of less than 24h, found in the major signalling pathways. The Notch effector hairy and enhancer of split Hes genes are ultradian oscillators. The physiological signals that synchronise and entrain Hes oscillators remain poorly understood. We investigated whether cellular metabolism modulates Hes1 cyclic expression. We demonstrated that, in mouse myoblasts (C2C12), Hes1 oscillation depends on reactive oxygen species (ROS), which are generated by the mitochondria electron transport chain and by NADPH oxidases NOXs. In vitro, the regulation of Hes1 by ROS occurs via the calcium-mediated signalling. The modulation of Hes1 by ROS was relevant in vivo, since perturbing ROS homeostasis was sufficient to alter Medaka (Oryzias latipes) somitogenesis, a process that is dependent on Hes1 ultradian oscillation during embryo development. Moreover, in a Medaka model for human microphthalmia with linear skin lesions syndrome, in which mitochondrial ROS homeostasis was impaired, we documented important somitogenesis defects and the deregulation of Hes homologues genes involved in somitogenesis. Notably, both molecular and developmental defects were rescued by antioxidant treatments. Our studies provide the first evidence of a coupling between cellular redox metabolism and an ultradian biological oscillator with important pathophysiological implication for somitogenesis.
超昼夜振荡器是周期小于 24 小时的循环表达基因，存在于主要信号通路中。Notch 效应因子 hairy 和 split Hes 基因的增强子是超昼夜振荡器。同步和调节 Hes 振荡器的生理信号仍知之甚少。我们研究了细胞代谢是否调节 Hes1 的循环表达。我们证明，在小鼠成肌细胞（C2C12）中，Hes1 的振荡依赖于活性氧（ROS），ROS 由线粒体电子传递链和 NADPH 氧化酶（NOXs）产生。在体外，ROS 通过钙介导的信号通路调节 Hes1。ROS 对 Hes1 的调节在体内是相关的，因为扰乱 ROS 动态平衡足以改变 Medaka（Oryzias latipes）体节形成，这一过程依赖于胚胎发育过程中 Hes1 的超昼夜振荡。此外，在人类小眼畸形伴线性皮肤损伤综合征的 Medaka 模型中，线粒体 ROS 动态平衡受损，我们记录了重要的体节形成缺陷和涉及体节形成的 Hes 同源基因的失调。值得注意的是，抗氧化剂治疗挽救了分子和发育缺陷。我们的研究首次提供了细胞氧化还原代谢与超昼夜生物振荡器之间偶联的证据，这对体节形成具有重要的病理生理学意义。
