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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 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 (up) IDA @ john @ Serial 133
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Author Chaves, I.; Pokorny, R.; Byrdin, M.; Hoang, N.; Ritz, T.; Brettel, K.; Essen, L.-O.; van der Horst, G.T.J.; Batschauer, A.; Ahmad, M.
Title The cryptochromes: blue light photoreceptors in plants and animals Type Journal Article
Year 2011 Publication Annual Review of Plant Biology Abbreviated Journal Annu Rev Plant Biol
Volume 62 Issue Pages 335-364
Keywords Adenosine Triphosphate/metabolism; Animals; Cryptochromes/chemistry/classification/*physiology; DNA Repair; Deoxyribodipyrimidine Photo-Lyase/chemistry/classification/physiology; Homing Behavior; Insects/physiology; *Light Signal Transduction; Magnetics; Mice; Oxidation-Reduction; Phosphorylation/physiology; Plants/*metabolism; blue light
Abstract Cryptochromes are flavoprotein photoreceptors first identified in Arabidopsis thaliana, where they play key roles in growth and development. Subsequently identified in prokaryotes, archaea, and many eukaryotes, cryptochromes function in the animal circadian clock and are proposed as magnetoreceptors in migratory birds. Cryptochromes are closely structurally related to photolyases, evolutionarily ancient flavoproteins that catalyze light-dependent DNA repair. Here, we review the structural, photochemical, and molecular properties of cry-DASH, plant, and animal cryptochromes in relation to biological signaling mechanisms and uncover common features that may contribute to better understanding the function of cryptochromes in diverse systems including in man.
Address Department of Genetics, Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands. i.chaves@erasmusmc.nl
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 1543-5008 ISBN Medium
Area Expedition Conference
Notes PMID:21526969 Approved no
Call Number (up) IDA @ john @ Serial 341
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Author Stevens, R.G.
Title Light-at-night, circadian disruption and breast cancer: assessment of existing evidence Type Journal Article
Year 2009 Publication International Journal of Epidemiology Abbreviated Journal Int J Epidemiol
Volume 38 Issue 4 Pages 963-970
Keywords Human Health; Animals; Blindness/complications/epidemiology; Breast Neoplasms/epidemiology/*etiology/metabolism; Chronobiology Disorders/*complications/epidemiology/metabolism; Circadian Rhythm/physiology; Disease Models, Animal; Female; Humans; Light Signal Transduction/physiology; Lighting/adverse effects; Melatonin/biosynthesis; Sleep/physiology; Time Factors; *Work Schedule Tolerance
Abstract BACKGROUND: Breast cancer incidence is increasing globally for largely unknown reasons. The possibility that a portion of the breast cancer burden might be explained by the introduction and increasing use of electricity to light the night was suggested >20 years ago. METHODS: The theory is based on nocturnal light-induced disruption of circadian rhythms, notably reduction of melatonin synthesis. It has formed the basis for a series of predictions including that non-day shift work would increase risk, blind women would be at lower risk, long sleep duration would lower risk and community nighttime light level would co-distribute with breast cancer incidence on the population level. RESULTS: Accumulation of epidemiological evidence has accelerated in recent years, reflected in an International Agency for Research on Cancer (IARC) classification of shift work as a probable human carcinogen (2A). There is also a strong rodent model in support of the light-at-night (LAN) idea. CONCLUSION: If a consensus eventually emerges that LAN does increase risk, then the mechanisms for the effect are important to elucidate for intervention and mitigation. The basic understanding of phototransduction for the circadian system, and of the molecular genetics of circadian rhythm generation are both advancing rapidly, and will provide for the development of lighting technologies at home and at work that minimize circadian disruption, while maintaining visual efficiency and aesthetics. In the interim, there are strategies now available to reduce the potential for circadian disruption, which include extending the daily dark period, appreciate nocturnal awakening in the dark, using dim red light for nighttime necessities, and unless recommended by a physician, not taking melatonin tablets.
Address Department of Community Medicine, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-6325, USA. bugs@uchc.edu
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 0300-5771 ISBN Medium
Area Expedition Conference
Notes PMID:19380369; PMCID:PMC2734067 Approved no
Call Number (up) LoNNe @ christopher.kyba @ Serial 527
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Author Berson, D.M.; Dunn, F.A.; Takao, M.
Title Phototransduction by retinal ganglion cells that set the circadian clock Type Journal Article
Year 2002 Publication Science (New York, N.Y.) Abbreviated Journal Science
Volume 295 Issue 5557 Pages 1070-1073
Keywords Human Health; Animals; Axons/ultrastructure; *Biological Clocks; *Circadian Rhythm; Dendrites/ultrastructure; Isoquinolines; Kinetics; Light; *Light Signal Transduction; Patch-Clamp Techniques; Rats; Rats, Sprague-Dawley; Retinal Ganglion Cells/chemistry/cytology/*physiology; Rod Opsins/analysis/physiology; Suprachiasmatic Nucleus/cytology/*physiology
Abstract Light synchronizes mammalian circadian rhythms with environmental time by modulating retinal input to the circadian pacemaker-the suprachiasmatic nucleus (SCN) of the hypothalamus. Such photic entrainment requires neither rods nor cones, the only known retinal photoreceptors. Here, we show that retinal ganglion cells innervating the SCN are intrinsically photosensitive. Unlike other ganglion cells, they depolarized in response to light even when all synaptic input from rods and cones was blocked. The sensitivity, spectral tuning, and slow kinetics of this light response matched those of the photic entrainment mechanism, suggesting that these ganglion cells may be the primary photoreceptors for this system.
Address Department of Neuroscience, Brown University, Providence, RI, 02912 USA. David_Berson@brown.edu
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 0036-8075 ISBN Medium
Area Expedition Conference
Notes PMID:11834835 Approved no
Call Number (up) LoNNe @ kagoburian @ Serial 720
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Author Bullough, J.D.; Rea, M.S.; Figueiro, M.G.
Title Of mice and women: light as a circadian stimulus in breast cancer research Type Journal Article
Year 2006 Publication Cancer Causes & Control : CCC Abbreviated Journal Cancer Causes Control
Volume 17 Issue 4 Pages 375-383
Keywords Human Health; Animals; Breast Neoplasms/*physiopathology; *Circadian Rhythm; *Disease Models, Animal; Female; Humans; *Light; Light Signal Transduction; Mammary Neoplasms, Animal/*physiopathology; Melatonin/metabolism; Mice; Muridae/metabolism
Abstract OBJECTIVE: Nocturnal rodents are frequently used as models in human breast cancer research, but these species have very different visual and circadian systems and, therefore, very different responses to optical radiation or, informally, light. Because of the impact of light on the circadian system and because recent evidence suggests that cancer risk might be related to circadian disruption, it is becoming increasingly clear that optical radiation must be properly characterized for both nocturnal rodents and diurnal humans to make significant progress in unraveling links between circadian disruption and breast cancer. In this paper, we propose a quantitative framework for comparing radiometric and photometric quantities in human and rodent studies. METHODS: We reviewed published research on light as a circadian stimulus for humans and rodents. Both suppression of nocturnal melatonin and phase shifting were examined as outcome measures for the circadian system. RESULTS: The data were used to develop quantitative comparisons regarding the absolute and spectral sensitivity for the circadian systems of humans and nocturnal rodents. CONCLUSIONS: Two models of circadian phototransduction, for mouse and humans, have been published providing spectral sensitivities for these two species. Despite some methodological variations among the studies reviewed, the circadian systems of nocturnal rodents are approximately 10,000 times more sensitive to optical radiation than that of humans. Circadian effectiveness of different sources for both humans and nocturnal rodents are offered together with a scale relating their absolute sensitivities. Instruments calibrated in terms of conventional photometric units (e.g., lux) will not accurately characterize the circadian stimulus for either humans or rodents.
Address Lighting Research Center, Rensselaer Polytechnic Institute, 21 Union Street, Troy, NY 12180, USA. bulloj@rpi.edu
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 0957-5243 ISBN Medium
Area Expedition Conference
Notes PMID:16596289 Approved no
Call Number (up) LoNNe @ kagoburian @ Serial 726
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