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Author Reddy, A.B.; O'Neill, J.S.
Title Healthy clocks, healthy body, healthy mind Type Journal Article
Year 2010 Publication Trends in Cell Biology Abbreviated Journal Trends Cell Biol
Volume (up) 20 Issue 1 Pages 36-44
Keywords Aging; Animals; Cell Cycle; *Circadian Rhythm; Humans; Neoplasms/genetics/metabolism; Signal Transduction
Abstract Circadian rhythms permeate mammalian biology. They are manifested in the temporal organisation of behavioural, physiological, cellular and neuronal processes. Whereas it has been shown recently that these approximately 24-hour cycles are intrinsic to the cell and persist in vitro, internal synchrony in mammals is largely governed by the hypothalamic suprachiasmatic nuclei that facilitate anticipation of, and adaptation to, the solar cycle. Our timekeeping mechanism is deeply embedded in cell function and is modelled as a network of transcriptional and/or post-translational feedback loops. Concurrent with this, we are beginning to understand how this ancient timekeeper interacts with myriad cell systems, including signal transduction cascades and the cell cycle, and thus impacts on disease. An exemplary area where this knowledge is rapidly expanding and contributing to novel therapies is cancer, where the Period genes have been identified as tumour suppressors. In more complex disorders, where aetiology remains controversial, interactions with the clockwork are only now starting to be appreciated.
Address Department of Clinical Neurosciences, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge CB2 OQQ, UK. abr20@cam.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0962-8924 ISBN Medium
Area Expedition Conference
Notes PMID:19926479; PMCID:PMC2808409 Approved no
Call Number IDA @ john @ Serial 133
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Author Reiter, R.J.; Tan, D.X.; Korkmaz, A.; Rosales-Corral, S.A.
Title Melatonin and stable circadian rhythms optimize maternal, placental and fetal physiology Type Journal Article
Year 2014 Publication Human Reproduction Update Abbreviated Journal Hum Reprod Update
Volume (up) 20 Issue 2 Pages 293-307
Keywords Human Health; Animals; Antioxidants/physiology; Biological Clocks/physiology; Circadian Rhythm/*physiology; Female; Fetus/*physiology; Humans; Mammals; Melatonin/biosynthesis/*physiology; Mice; Oxidative Stress/physiology; Parturition/physiology; Placenta/metabolism/*physiology; Pre-Eclampsia/etiology/metabolism; Pregnancy; Uterus/metabolism; circadian rhythms; fetus; melatonin; placenta; pre-eclampsia
Abstract BACKGROUND: Research within the last decade has shown melatonin to have previously-unsuspected beneficial actions on the peripheral reproductive organs. Likewise, numerous investigations have documented that stable circadian rhythms are also helpful in maintaining reproductive health. The relationship of melatonin and circadian rhythmicity to maternal and fetal health is summarized in this review. METHODS: Databases were searched for the related published English literature up to 15 May 2013. The search terms used in various combinations included melatonin, circadian rhythms, biological clock, suprachiasmatic nucleus, ovary, pregnancy, uterus, placenta, fetus, pre-eclampsia, intrauterine growth restriction, ischemia-reperfusion, chronodisruption, antioxidants, oxidative stress and free radicals. The results of the studies uncovered are summarized herein. RESULTS: Both melatonin and circadian rhythms impact reproduction, especially during pregnancy. Melatonin is a multifaceted molecule with direct free radical scavenging and indirect antioxidant activities. Melatonin is produced in both the ovary and in the placenta where it protects against molecular mutilation and cellular dysfunction arising from oxidative/nitrosative stress. The placenta, in particular, is often a site of excessive free radical generation due to less than optimal adhesion to the uterine wall, which leads to either persistent hypoxia or intermittent hypoxia and reoxygenation, processes that cause massive free radical generation and organ dysfunction. This may contribute to pre-eclampsia and other disorders which often complicate pregnancy. Melatonin has ameliorated free radical damage to the placenta and to the fetus in experiments using non-human mammals. Likewise, the maintenance of a regular maternal light/dark and sleep/wake cycle is important to stabilize circadian rhythms generated by the maternal central circadian pacemaker, the suprachiasmatic nuclei. Optimal circadian rhythmicity in the mother is important since her circadian clock, either directly or indirectly via the melatonin rhythm, programs the developing master oscillator of the fetus. Experimental studies have shown that disturbed maternal circadian rhythms, referred to as chronodisruption, and perturbed melatonin cycles have negative consequences for the maturing fetal oscillators, which may lead to psychological and behavioral problems in the newborn. To optimize regular circadian rhythms and prevent disturbances of the melatonin cycle during pregnancy, shift work and bright light exposure at night should be avoided, especially during the last trimester of pregnancy. Finally, melatonin synergizes with oxytocin to promote delivery of the fetus. Since blood melatonin levels are normally highest during the dark period, the propensity of childbirth to occur at night may relate to the high levels of melatonin at this time which work in concert with oxytocin to enhance the strength of uterine contractions. CONCLUSIONS: A number of conclusions naturally evolve from the data summarized in this review: (i) melatonin, of both pineal and placental origin, has essential functions in fetal maturation and placenta/uterine homeostasis; (ii) circadian clock genes, which are components of all cells including those in the peripheral reproductive organs, have important roles in reproductive and organismal (fetal and maternal) physiology; (iii) due to the potent antioxidant actions of melatonin, coupled with its virtual absence of toxicity, this indoleamine may have utility in the treatment of pre-eclampsia, intrauterine growth restriction, placental and fetal ischemia/reperfusion, etc. (iv) the propensity for parturition to occur at night may relate to the synergism between the nocturnal increase in melatonin and oxytocin.
Address Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1355-4786 ISBN Medium
Area Expedition Conference
Notes PMID:24132226 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 504
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Author Rumanova, V.S.; Okuliarova, M.; Zeman, M.
Title Differential Effects of Constant Light and Dim Light at Night on the Circadian Control of Metabolism and Behavior Type Journal Article
Year 2020 Publication International Journal of Molecular Sciences Abbreviated Journal Int J Mol Sci
Volume (up) 21 Issue 15 Pages
Keywords Review; Animals; behavior; chronodisruption; circadian; corticosterone; dim light at night; hormones; locomotor activity; melatonin; metabolism; rhythms
Abstract The disruption of circadian rhythms by environmental conditions can induce alterations in body homeostasis, from behavior to metabolism. The light:dark cycle is the most reliable environmental agent, which entrains circadian rhythms, although its credibility has decreased because of the extensive use of artificial light at night. Light pollution can compromise performance and health, but underlying mechanisms are not fully understood. The present review assesses the consequences induced by constant light (LL) in comparison with dim light at night (dLAN) on the circadian control of metabolism and behavior in rodents, since such an approach can identify the key mechanisms of chronodisruption. Data suggest that the effects of LL are more pronounced compared to dLAN and are directly related to the light level and duration of exposure. Dim LAN reduces nocturnal melatonin levels, similarly to LL, but the consequences on the rhythms of corticosterone and behavioral traits are not uniform and an improved quantification of the disrupted rhythms is needed. Metabolism is under strong circadian control and its disruption can lead to various pathologies. Moreover, metabolism is not only an output, but some metabolites and peripheral signal molecules can feedback on the circadian clockwork and either stabilize or amplify its desynchronization.
Address Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovicova 6, 842 15 Bratislava, Slovakia
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1422-0067 ISBN Medium
Area Expedition Conference
Notes PMID:32751870 Approved no
Call Number GFZ @ kyba @ Serial 3062
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Author Cajochen, C.; Altanay-Ekici, S.; Munch, M.; Frey, S.; Knoblauch, V.; Wirz-Justice, A.
Title Evidence that the lunar cycle influences human sleep Type Journal Article
Year 2013 Publication Current Biology : CB Abbreviated Journal Curr Biol
Volume (up) 23 Issue 15 Pages 1485-1488
Keywords Adult; Aged; Cross-Sectional Studies; Electroencephalography; Female; Humans; Hydrocortisone/analysis/metabolism; Male; Melatonin/analysis/metabolism; Middle Aged; Moon; Nontherapeutic Human Experimentation; Periodicity; Saliva/metabolism; Sleep/*physiology; Sleep Stages/physiology; Young Adult
Abstract Endogenous rhythms of circalunar periodicity ( approximately 29.5 days) and their underlying molecular and genetic basis have been demonstrated in a number of marine species [1, 2]. In contrast, there is a great deal of folklore but no consistent association of moon cycles with human physiology and behavior [3]. Here we show that subjective and objective measures of sleep vary according to lunar phase and thus may reflect circalunar rhythmicity in humans. To exclude confounders such as increased light at night or the potential bias in perception regarding a lunar influence on sleep, we retrospectively analyzed sleep structure, electroencephalographic activity during non-rapid-eye-movement (NREM) sleep, and secretion of the hormones melatonin and cortisol found under stringently controlled laboratory conditions in a cross-sectional setting. At no point during and after the study were volunteers or investigators aware of the a posteriori analysis relative to lunar phase. We found that around full moon, electroencephalogram (EEG) delta activity during NREM sleep, an indicator of deep sleep, decreased by 30%, time to fall asleep increased by 5 min, and EEG-assessed total sleep duration was reduced by 20 min. These changes were associated with a decrease in subjective sleep quality and diminished endogenous melatonin levels. This is the first reliable evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues.
Address Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4012 Basel, Switzerland. christian.cajochen@upkbs.ch
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-9822 ISBN Medium
Area Expedition Conference
Notes PMID:23891110 Approved no
Call Number IDA @ john @ Serial 140
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Author Sahar, S.; Sassone-Corsi, P.
Title Regulation of metabolism: the circadian clock dictates the time Type Journal Article
Year 2012 Publication Trends in Endocrinology and Metabolism: TEM Abbreviated Journal Trends Endocrinol Metab
Volume (up) 23 Issue 1 Pages 1-8
Keywords Animals; Chronobiology Disorders/metabolism; *Circadian Clocks; *Circadian Rhythm; Circadian Rhythm Signaling Peptides and Proteins/metabolism; *Energy Metabolism; Humans; Metabolome
Abstract Circadian rhythms occur with a periodicity of approximately 24h and regulate a wide array of metabolic and physiologic functions. Accumulating epidemiological and genetic evidence indicates that disruption of circadian rhythms can be directly linked to many pathological conditions, including sleep disorders, depression, metabolic syndrome and cancer. Intriguingly, several molecular gears constituting the clock machinery have been found to establish functional interplays with regulators of cellular metabolism. Although the circadian clock regulates multiple metabolic pathways, metabolite availability and feeding behavior can in turn regulate the circadian clock. An in-depth understanding of this reciprocal regulation of circadian rhythms and cellular metabolism may provide insights into the development of therapeutic intervention against specific metabolic disorders.
Address Center for Epigenetics and Metabolism, School of Medicine, University of California, Irvine, CA 92697, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1043-2760 ISBN Medium
Area Expedition Conference
Notes PMID:22169754; PMCID:PMC3259741 Approved no
Call Number IDA @ john @ Serial 151
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