title: Evidence for clock genes circadian rhythms in human full-term placenta.
abstract: Biological rhythms are driven by endogenous biological clocks; in mammals, the master clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. This master pacemaker can synchronize other peripheral oscillators in several tissues such as some involved in endocrine or reproductive functions. The presence of an endogenous placental clock has received little attention. In fact, there are no studies in human full-term placentas. To test the existence of an endogenous pacemaker in this tissue we have studied the expression of circadian locomoter output cycles kaput (Clock), brain and muscle arnt-like (Bmal)1, period (Per)2, and cryptochrome (Cry)1 mRNAs at 00, 04, 08, 12, 16, and 20 hours by qPCR. The four clock genes studied are expressed in full-term human placenta. The results obtained allow us to suggest that a peripheral oscillator exists in human placenta. Data were analyzed using Fourier series where only the Clock and Bmal1 expression shows a circadian rhythm.
authors.affiliation: a Transplants, Cell Therapy and Regenerative Medicine Unit, Central University Hospital of Asturias (HUCA) , Oviedo , Spain .
authors.forename: Silvia
authors.initials: S
authors.lastname: Pérez
authors.affiliation: b Area of Physiology, Department of Functional Biology, University of Oviedo , Oviedo , Spain .
authors.forename: Lucía
authors.initials: L
authors.lastname: Murias
authors.affiliation: c Department of Gynecology and Obstetrics , HUCA , Oviedo , Spain , and.
authors.forename: Catalina
authors.initials: C
authors.lastname: Fernández-Plaza
authors.affiliation: d Area of Computation Science and Artificial Intelligence, Department of Computer Science, University of Oviedo , Oviedo , Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Díaz
authors.affiliation: b Area of Physiology, Department of Functional Biology, University of Oviedo , Oviedo , Spain .
authors.forename: Celestino
authors.initials: C
authors.lastname: González
authors.affiliation: a Transplants, Cell Therapy and Regenerative Medicine Unit, Central University Hospital of Asturias (HUCA) , Oviedo , Spain .
authors.forename: Jesús
authors.initials: J
authors.lastname: Otero
authors.affiliation: b Area of Physiology, Department of Functional Biology, University of Oviedo , Oviedo , Spain .
authors.forename: Elena
authors.initials: E
authors.lastname: Díaz
mesh_terms: D056930:ARNTL Transcription Factors / Q000378:metabolism*; D000328:Adult; D056926:CLOCK Proteins / Q000378:metabolism*; D002940:Circadian Rhythm; D056931:Cryptochromes / Q000378:metabolism*; D005260:Female; D006801:Humans; D056950:Period Circadian Proteins / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy
chemical_list: D056930:ARNTL Transcription Factors; C538960:BMAL1 protein, human; C538963:CRY1 protein, human; D056931:Cryptochromes; C421902:PER2 protein, human; D056950:Period Circadian Proteins; D056926:CLOCK Proteins; C538943:CLOCK protein, human
keywords: Circadian rhythm; clock genes; full-term human placenta; qPCR