title: A novel role of microRNA 17-5p in the modulation of circadian rhythm.
abstract: The circadian clock helps living organisms to adjust their physiology and behaviour to adapt environmental day-night cycles. The period length of circadian rhythm reflects the endogenous cycle transition rate and is modulated by environmental cues or internal molecules, and the latter are of substantial importance but remain poorly revealed. Here, we demonstrated that microRNA 17-5p (miR-17-5p), which has been associated with tumours, was an important factor in controlling the circadian period. MiR-17-5p was rhythmically expressed in synchronised fibroblasts and mouse master clock suprachiasmatic nuclei (SCN). MiR-17-5p and the gene Clock exhibited a reciprocal regulation: miR-17-5p inhibited the translation of Clock by targeting the 3'UTR (untranslated region) of Clock mRNA, whereas the CLOCK protein directly bound to the promoter of miR-17 and enhanced its transcription and production of miR-17-5p. In addition, miR-17-5p suppressed the expression of Npas2. At the cellular level, bidirectional changes in miR-17-5p or CLOCK resulted in CRY1 elevation. Accordingly, in vivo, both increase and decrease of miR-17-5p in the mouse SCN led to an increase in CRY1 level and shortening of the free-running period. We conclude that miR-17-5p has an important role in the inspection and stabilisation of the circadian-clock period by interacting with Clock and Npas2 and potentially via the output of CRY1.
authors.affiliation: Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China.
authors.forename: Su-Yu
authors.initials: SY
authors.lastname: Yang
authors.affiliation: Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China.
authors.forename: Ji-Min
authors.initials: JM
authors.lastname: Cao
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D056926:CLOCK Proteins / Q000378:metabolism; D002940:Circadian Rhythm; D056931:Cryptochromes / Q000378:metabolism; D005347:Fibroblasts / Q000502:physiology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D051379:Mice; D035683:MicroRNAs / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D013493:Suprachiasmatic Nucleus / Q000502:physiology
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D056931:Cryptochromes; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; C538964:Cry1 protein, mouse; C543614:Mirn17 microRNA, mouse; C491259:Npas2 protein, mouse