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Circadian rhythms

Stefano Schiaffino, Bert Blaauw, Kenneth A Dyar
The circadian oscillations of muscle genes are controlled either directly by the intrinsic muscle clock or by extrinsic factors, such as feeding, hormonal signals, or neural influences, which are in turn regulated by the central pacemaker, the suprachiasmatic nucleus of the hypothalamus. A unique feature of circadian rhythms in skeletal muscle is motor neuron-dependent contractile activity, which can affect the oscillation of a number of muscle genes independently of the muscle clock. The role of the intrinsic muscle clock has been investigated using different Bmal1 knockout (KO) models...
2016: Skeletal Muscle
Henrik Oster, Etienne Challet, Volker Ott, Emanuela Arvat, E Ronald de Kloet, Derk-Jan Dijk, Stafford Lightman, Alexandros Vgontzas, Eve Van Cauter
Adrenal glucocorticoids are major modulators of multiple functions, including energy metabolism, stress responses, immunity, and cognition. The endogenous secretion of glucocorticoids is normally characterized by a prominent and robust circadian (around 24 hours) oscillation, with a daily peak around the time of the habitual sleep-wake transition and minimal levels in the evening and early part of the night. It has been long recognized that this 24-h rhythm partly reflects the activity of a master circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus...
October 17, 2016: Endocrine Reviews
Sairam Parthasarathy, Mary A Carskadon, Girardin Jean-Louis, Judith Owens, Adam Bramoweth, Daniel Combs, Lauren Hale, Elizabeth Harrison, Chantelle N Hart, Brant P Hasler, Sarah M Honaker, Elisabeth Hertenstein, Samuel Kuna, Clete Kushida, Jessica C Levenson, Caitlin Murray, Allan I Pack, Vivek Pillai, Kristi Pruiksma, Azizi Seixas, Patrick Strollo, Saurabh S Thosar, Natasha Williams, Daniel Buysse
A wealth of scientific knowledge is being generated in sleep and circadian science. In order for us to realize the return on investment for such scientific knowledge and to improve the health of the nation, we need to disseminate and implement research findings into practice. An implementation gap - termed a "quality chasm" by the Institutes of Medicine - separates the scientific knowledge we possess and the implementation of such knowledge into preventative interventions or healthcare treatments. It is frequently reported that a time lag of 17 years transpires before medical research reaches clinical practice...
October 10, 2016: Sleep
Song Wu, Andrew Fesler, Jingfang Ju
AIM: To establish a connection between microRNA (miRNAs), circadian rhythm, and colorectal cancer patient survival. METHODS: Genomic and clinical data were extracted from The Cancer Genome Atlas (TCGA) colorectal cancer database, and the expression levels of candidate miRNAs and a set of circadian rhythm-related genes (Per1, Per2, Per3, Bmal1), and genes associated with chemosensitivity (thymidylate synthase, dihydrofolate reductase) were assessed for any correlations among their expression...
January 2016: Cancer Transl Med
Jennifer Gile, Tobias Eckle
Cardiovascular disease is the number one cause of death worldwide. A powerful strategy for cardioprotection would be to identify specific molecules or targets that mimic ischemic preconditioning (IP), where short non-lethal episodes of ischemia and reperfusion prior to myocardial infarction result in dramatic reduction of infarct sizes. Since 1960 researchers believed that adenosine has a strong cardio-protective potential. In fact, with the discovery of cardiac IP in 1986 by Murry et al., adenosine was the first identified molecule that was used in studying the underlying mechanism of IP...
2016: Journal of Nature and Science
L Müller, D Weinert
In a natural environment, social abilities of an animal are important for its survival. Particularly, it must recognize its own social rank and the social rank of a conspecific and have a good social memory. While the role of the circadian system for object and spatial recognition and memory is well known, the impact of the social rank and circadian disruptions on social recognition and memory were not investigated so far. In the present study, individual recognition of social rank and social memory performance of Djungarian hamsters revealing different circadian phenotypes were investigated...
October 12, 2016: Behavioural Processes
Karen Spruyt, Wiebe Braam, Marcel Smits, Leopold Mg Curfs
AIMS: Individuals with Smith-Magenis syndrome (SMS) are reported to have a disrupted circadian rhythm. Our aim was to examine problematic sleeping in those attending our sleep clinic for the first time. METHODS: At intake, caregivers of 50 children and nine adults with SMS were surveyed about the sleep pattern and potential melatonin administration. Sampling of salivary melatonin levels was performed. RESULTS: At intake, exogenous melatonin was used by 16 children (27...
October 14, 2016: CNS Neuroscience & Therapeutics
Susanne A Bengesser, Eva Z Reininghaus, Nina Lackner, Armin Birner, Frederike T Fellendorf, Martina Platzer, Nora Kainzbauer, Bernhard Tropper, Christa Hörmanseder, Robert Queissner, Hans-Peter Kapfhammer, Sandra J Wallner-Liebmann, Robert Fuchs, Erwin Petek, Christian Windpassinger, Mario Schnalzenberger, Bernd Reininghaus, Bernd Evert, Andreas Waha
OBJECTIVES: The clock gene ARNTL is associated with the transcription activation of monoamine oxidase A according to previous literature. Thus, we hypothesised that methylation of ARNTL may differ between bipolar disorder (BD) and controls. METHODS: The methylation status of one CpG island covering the first exon of ARNTL (PS2) and one site in the 5' region of ARNTL (cg05733463) were analysed in patients with BD (n = 151) versus controls (n = 66). Methylation analysis was performed by bisulphite-conversion of DNA from fasting blood with the EpiTect Bisulfite Kit, PCR and pyrosequencing...
October 14, 2016: World Journal of Biological Psychiatry
Lone Baandrup, Ole Bernt Fasmer, Birte Yding Glenthøj, Poul Jørgen Jennum
BACKGROUND: Patients with severe mental illness often suffer from disruptions in circadian rest-activity cycles, which might partly be attributed to ongoing psychopharmacological medication. Benzodiazepines are frequently prescribed for prolonged periods despite recommendations of only short-term usage. Melatonin, a naturally occurring nocturnal hormone, has the potential to stabilize disrupted circadian rhythmicity. Our aim was to investigate how prolonged-release melatonin affects rest-activity patterns in medicated patients with severe mental illness and if benzodiazepine dose reduction is associated with changes in circadian rhythm parameters...
October 13, 2016: BMC Psychiatry
Adrian Andrzej Chrobak, Anna Tereszko, Daria Dembinska-Krajewska, Aleksandra Arciszewska, Marcin Siwek, Dominika Dudek, Janusz Rybakowski
Chronotype is a stable trait presenting one's circardian preference. Since chronotype disturbances are common in patients with affective disorders, our aim is to evaluate chronotypes related to affective temperaments, measured with the temperament evaluation of Memphis, Pisa and San Diego-Autoquestionnaire (TEMPS-A). The study included 618 subjects (151 men and 467 women) within the framework of web-based design. They all fulfilled a questionnaire, consisting of the Composite Scale of Morningness (CSM), Sleep Wake Pattern Assessment Questionnaire (SWPAQ), and the TEMPS-A scale...
October 13, 2016: Chronobiology International
Lisa A Gottlieb, Anniek Lubberding, Anders Peter Larsen, Morten B Thomsen
Potassium Channel Interacting Protein 2 (KChIP2) is suggested to be responsible for the circadian rhythm in repolarization duration, ventricular arrhythmias, and sudden cardiac death. We investigated the hypothesis that there is no circadian rhythm in QT interval in the absence of KChIP2. Implanted telemetric devices recorded electrocardiogram continuously for 5 days in conscious wild-type mice (WT, n = 9) and KChIP2(-/-) mice (n = 9) in light:dark periods and in complete darkness. QT intervals were determined from all RR intervals and corrected for heart rate (QT100 = QT/(RR/100)(1/2))...
October 13, 2016: Chronobiology International
Mel S Lee, Tsung-Cheng Yin, Pei-Hsun Sung, John Y Chiang, Cheuk-Kwan Sun, Hon-Kan Yip
Despite state-of-the-art pharmaceutical regimens, continuous improvements in diagnostic techniques as well as refinements in equipment and interventional procedures, many diseases remain refractory to conventional therapies. Recent advances in stem cell (SC) biology have opened an avenue to exploring its therapeutic potential in various disease entities, especially those that are ischemia-related and refractory to conventional treatment. A number of experimental studies and clinical trials have already demonstrated promising outcomes...
October 13, 2016: Journal of Pineal Research
Oliver Rawashdeh, Shannon J Clough, Randall L Hudson, Margarita L Dubocovich
The suprachiasmatic nucleus (SCN)-often referred to as the master circadian clock-is essential in generating physiologic rhythms and orchestrating synchrony among circadian clocks. This study tested the hypothesis that periodic motivation induced by rhythmically pairing 2 reinforcing stimuli [methamphetamine (METH) and running wheel (RW)] restores autonomous circadian activity in arrhythmic SCN-lesioned (SCNX) C3H/HeN mice. Sham-operated and SCNX mice were treated with either METH (1.2 mg/kg, i.p.) or vehicle in association, dissociation, or absence of an RW...
October 12, 2016: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
Michael Bennardo, Faisal J Alibhai, Elena V Tsimakouridze, Nirmala Chinnappareddy, Peter Podobed, Cristine J Reitz, W Glen Pyle, Jeremy A Simpson, Tami A Martino
Diurnal or circadian rhythms are fundamentally important for healthy cardiovascular physiology, and play a role in timing of onset and tolerance to myocardial infarction (MI) in patients. Whether time of day of MI triggers different molecular and cellular responses that can influence myocardial remodelling is not known. This study was designed to test whether time of day of MI triggers different gene expression, humoral, and innate inflammatory responses that contribute to cardiac repair after MI. Mice were infarcted by left anterior descending coronary artery ligation (MI model) within a 2 hour time window either shortly after lights on or lights off, and the early remodelling responses at 8 hours post infarction were examined...
October 12, 2016: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
Shaul Mezan, Jean Daniel Feuz, Bart Deplancke, Sebastian Kadener
Circadian clocks generate 24-hr rhythms in physiology and behavior. Despite numerous studies, it is still uncertain how circadian rhythms emerge from their molecular and neural constituents. Here, we demonstrate a tight connection between the molecular and neuronal circadian networks. Using fluorescent transcriptional reporters in a Drosophila ex vivo brain culture system, we identified a reciprocal negative regulation between the master circadian regulator CLK and expression of pdf, the main circadian neuropeptide...
October 11, 2016: Cell Reports
Fabianne Furtado, Bruno da Silva B Gonçalves, Isabela Lopes Laguardia Abranches, Ana Flávia Abrantes, Arturo Forner-Cordero
The lack of sleep, both in quality and quantity, is an increasing problem in modern society, often related to workload and stress. A number of studies have addressed the effects of acute (total) sleep deprivation on postural control. However, up to date, the effects of chronic sleep deficits, either in quantity or quality, have not been analyzed. Thirty healthy adults participated in the study that consisted of registering activity with a wrist actigraph for more than a week before performing a series of postural control tests...
2016: PloS One
Kazuyoshi Murata, Sayuri Hagiwara, Yoshitaka Kimori, Yasuko Kaneko
Some cyanobacteria exhibit compaction of DNA in synchrony with their circadian rhythms accompanying cell division. Since the structure is transient, it has not yet been described in detail. Here, we successfully visualize the ultrastructure of compacted DNA in the cyanobacterium Synechococcus elongatus PCC 7942 under rigorous synchronized cultivation by means of high-voltage cryo-electron tomography. In 3D reconstructions of rapidly frozen cells, the compacted DNA appears as an undulating rod resembling a eukaryotic condensed chromosome...
October 12, 2016: Scientific Reports
Udaya Seneviratne, Ray C Boston, Mark Cook, Wendyl D'Souza
OBJECTIVE: We sought to investigate the temporal patterns and sleep-wake cycle-related epileptiform discharges (EDs) in genetic generalized epilepsies (GGEs). METHODS: We studied 24-hour ambulatory electroencephalography (EEG) recordings of patients with GGE, diagnosed and classified according to the International League against Epilepsy criteria. We manually coded the type of discharge, time of occurrence, duration, and arousal state of each ED. We employed mixed effects Poisson regression modeling to study the temporal distribution of epileptiform discharges...
October 7, 2016: Epilepsy & Behavior: E&B
Walter Wilczynski, Deborah I Lutterschmidt
A new study shows that nocturnal courtship vocalization is regulated by a circadian rhythm and potentiated by melatonin at multiple timescales. These findings are in contrast to those in diurnal vocalizers and provide a striking example of melatonin's niche-specific functions.
October 10, 2016: Current Biology: CB
Patrick Vancura, Tanja Wolloscheck, Kenkichi Baba, Gianluca Tosini, P Michael Iuvone, Rainer Spessert
The energy metabolism of the retina might comply with daily changes in energy demand and is impaired in diabetic retinopathy-one of the most common causes of blindness in Europe and the USA. The aim of this study was to investigate putative adaptation of energy metabolism in healthy and diabetic retina. Hence expression analysis of metabolic pathway genes was performed using quantitative polymerase chain reaction, semi-quantitative western blot and immunohistochemistry. Transcriptional profiling of key enzymes of energy metabolism identified transcripts of mitochondrial fatty acid β-oxidation enzymes, i...
2016: PloS One
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