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Author Miler, M.; Sosic-Jurjevic, B.; Nestorovic, N.; Ristic, N.; Medigovic, I.; Savin, S.; Milosevic, V.
Title Morphological and functional changes in pituitary-thyroid axis following prolonged exposure of female rats to constant light Type Journal Article
Year 2014 Publication Journal of Morphology Abbreviated Journal J Morphol
Volume 275 Issue 10 Pages 1161-1172
Keywords TSH cells; constant light; immunohistochemistry; pituitary; rat; thyroid; light exposure
Abstract Light regulates numerous physiological functions and synchronizes them with the environment, in part by adjusting secretion of different hormones. We hypothesized that constant light (CL) would disturb pituitary-thyroid axis. Our aim was to determine morphological and functional changes in this endocrine system in such extreme conditions and, based on the obtained results, to propose the underlying mechanism(s). Starting from the thirtieth postnatal day, female Wistar rats were exposed to CL (600 lx) for the following 95 days. The controls were maintained under the regular laboratory lighting conditions. After decapitation, pituitaries and thyroids were prepared for further histomorphometric, immunohistochemical, and immunofluorescence examinations. Concentration of thyroid stimulating hormone (TSH), total T4 and T3 (TH) were determined. Thyroid tissue of light-treated rats was characterized by microfollicular structure. We detected no change in total thyroid volume, localization and accumulation of thyroglobulin, thyroid peroxidase, and sodium-iodide symporter in the follicular epithelium of CL rats. The volume of follicular epithelium and activation index were increased, while volume of the colloid and serum levels of TH decreased. In the pituitary, the relative intensity of TSH beta-immunofluorescence signal within the cytoplasm of thyrotrophs increased, but their average cell volume and the relative volume density decreased. Serum TSH was unaltered. We conclude that exposure of female rats to CL induced alterations in pituitary-thyroid axis. Thyroid tissue was characterized by microfollicular structure. Serum TH levels were reduced without accompanying increase in serum TSH. We hypothesize that increased secretion and clearance of TH together with unchanged or even decreased hormonal synthesis, resulted in decreased serum TH levels in CL group. We assume this decrease consequently led to increased synthesis and/or accumulation of pituitary TSH. However, decreased average TSH cell volume and relative volume density, together with unchanged serum TSH, point to additional, negative regulation of thyrotrophs. J. Morphol., 2014. (c) 2014 Wiley Periodicals, Inc.
Address Department of Cytology, Institute for Biological Research “Sinisa Stankovic,” University of Belgrade, Belgrade, Serbia
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 0022-2887 ISBN Medium
Area Expedition Conference
Notes (up) PMID:24797691 Approved no
Call Number IDA @ john @ Serial 304
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Author van Diepen, H.C.; Foster, R.G.; Meijer, J.H.
Title A colourful clock Type Journal Article
Year 2015 Publication PLoS Biology Abbreviated Journal PLoS Biol
Volume 13 Issue 5 Pages e1002160
Keywords Animals; Commentary; *Circadian Rhythm; suprachiasmatic nuclei; melanopsin; retinal ganglion cells; entrainment; photoperiod
Abstract Circadian rhythms are an essential property of life on Earth. In mammals, these rhythms are coordinated by a small set of neurons, located in the suprachiasmatic nuclei (SCN). The environmental light/dark cycle synchronizes (entrains) the SCN via a distinct pathway, originating in a subset of photosensitive retinal ganglion cells (pRGCs) that utilize the photopigment melanopsin (OPN4). The pRGCs are also innervated by rods and cones and, so, are both endogenously and exogenously light sensitive. Accumulating evidence has shown that the circadian system is sensitive to ultraviolet (UV), blue, and green wavelengths of light. However, it was unclear whether colour perception itself can help entrain the SCN. By utilizing both behavioural and electrophysiological recording techniques, Walmsley and colleagues show that multiple photic channels interact and enhance the capacity of the SCN to synchronize to the environmental cycle. Thus, entrainment of the circadian system combines both environmental irradiance and colour information to ensure that internal and external time are appropriately aligned.
Address Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University medical School, Leiden, The Netherlands
Corporate Author Thesis
Publisher PLOS Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1544-9173 ISBN Medium
Area Expedition Conference
Notes (up) PMID:25996907; PMCID:PMC4440787 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 1183
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Author Bapary, M.A.J.; Takano, J.-I.; Soma, S.; Sankai, T.
Title Effect of blue LED light and antioxidants potential in a somatic cell Type Journal Article
Year 2019 Publication Cell Biology International Abbreviated Journal Cell Biol Int
Volume 43 Issue 11 Pages 1296-1306
Keywords Cells; Biology; LED; blue light; Antioxidants; cell death
Abstract Light is an indispensable part of routine laboratory works in which conventional light is generally used. Light-emitting diodes (LEDs) have come to replace the conventional light thus could be a potent target in biomedical studies. Since blue light is a major component of visible light wavelength, in this study, using a somatic cell from African green monkey kidney, we assessed the possible consequences of blue spectra of LED light in future animal experiments and proposed a potent mitigation against light induced damages. COS-7 cells were exposed to blue LED light (450 nm) and the growth and DNA damage were assessed at different exposure times. A higher suppression in cell growth and viability was observed under a longer period of blue LED light exposure. The number of apoptotic cells increased as light exposure time was prolonged. Reactive oxygen species generation was also elevated in accordance to the extension of light exposure times. A comparison to dark-maintained cells revealed that the upregulation of ROS by blue LED light plays a significant role in causing cellular dysfunction in DNA in a time-dependent manner. In turn, antioxidant treatment has shown to improve the cell growth and viability under blue LED light conditions. This indicates that antioxidants are potential against blue LED light-induced somatic cell damage. It is expected that this study will contribute to the understanding of the basic mechanism of somatic cell death under visible light and to maximize the beneficial use of LED light in future animal experiments.
Address Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Japan
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 1065-6995 ISBN Medium
Area Expedition Conference
Notes (up) PMID:30958611 Approved no
Call Number GFZ @ kyba @ Serial 2328
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Author Hong, F.; Pan, S.; Xu, P.; Xue, T.; Wang, J.; Guo, Y.; Jia, L.; Qiao, X.; Li, L.; Zhai, Y.
Title Melatonin Orchestrates Lipid Homeostasis through the Hepatointestinal Circadian Clock and Microbiota during Constant Light Exposure Type Journal Article
Year 2020 Publication Cells Abbreviated Journal Cells
Volume 9 Issue 2 Pages in press
Keywords Animals; Cells; Lan; hepatointestinal; lipid homeostasis; melatonin; microbiota
Abstract Misalignment between natural light rhythm and modern life activities induces disruption of the circadian rhythm. It is mainly evident that light at night (LAN) interferes with the human endocrine system and contributes to the increasing rates of obesity and lipid metabolic disease. Maintaining hepatointestinal circadian homeostasis is vital for improving lipid homeostasis. Melatonin is a chronobiotic substance that plays a main role in stabilizing bodily rhythm and has shown beneficial effects in protecting against obesity. Based on the dual effect of circadian rhythm regulation and antiobesity, we tested the effect of melatonin in mice under constant light exposure. Exposure to 24-h constant light (LL) increased weight and insulin resistance compared with those of the control group (12-h light-12-h dark cycle, LD), and simultaneous supplementation in the melatonin group (LLM) ameliorated this phenotype. Constant light exposure disturbed the expression pattern of a series of transcripts, including lipid metabolism, circadian regulation and nuclear receptors in the liver. Melatonin also showed beneficial effects in improving lipid metabolism and circadian rhythm homeostasis. Furthermore, the LL group had increased absorption and digestion of lipids in the intestine as evidenced by the elevated influx of lipids in the duodenum and decrease in the efflux of lipids in the jejunum. More interestingly, melatonin ameliorated the gut microbiota dysbiosis and improved lipid efflux from the intestine. Thus, these findings offer a novel clue regarding the obesity-promoting effect attributed to LAN and suggest a possibility for obesity therapy by melatonin in which melatonin could ameliorate rhythm disorder and intestinal dysbiosis.
Address Key Laboratory for Cell Proliferation and Regulation Biology of State Education Ministry, College of Life Sciences, Beijing Normal University, Beijing 100875, China
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 2073-4409 ISBN Medium
Area Expedition Conference
Notes (up) PMID:32093272 Approved no
Call Number GFZ @ kyba @ Serial 2854
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