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Circadian disruption

Akihiko Taguchi, Yasuharu Ohta, Yukio Tanizawa
Type 2 diabetes mellitus is characterized by the loss of ß-cell function and mass, resulting from interactions between genetic predisposition and various environmental factors1 . One environmental condition identified as a risk factor for type 2 diabetes mellitus is circadian rhythm disruption, which is induced by shift work or sleep disturbance. However, the mechanism whereby circadian disruption leads to impaired glucose metabolism is not well understood. This article is protected by copyright. All rights reserved...
March 15, 2018: Journal of Diabetes Investigation
M G Carta, A Preti, H S Akiskal
Human population is increasing in immense cities with millions of inhabitants, in which life is expected to run 24 hours a day for seven days a week (24/7). Noise and light pollution are the most reported consequences, with a profound impact on sleep patterns and circadian biorhythms. Disruption of sleep and biorhythms has severe consequences on many metabolic pathways. Suppression of melatonin incretion at night and the subsequent effect on DNA methylation may increase the risk of prostate and breast cancer...
2018: Clinical Practice and Epidemiology in Mental Health: CP & EMH
Jodi R Paul, Hira A Munir, Thomas van Groen, Karen L Gamble
Disruption of circadian rhythms is commonly reported in individuals with Alzheimer's disease (AD). Neurons in the primary circadian pacemaker, the suprachiasmatic nucleus (SCN), exhibit daily rhythms in spontaneous neuronal activity which are important for maintaining circadian behavioral rhythms. Disruption of SCN neuronal activity has been reported in animal models of other neurodegenerative disorders; however, the effect of AD on SCN neurophysiology remains unknown. In this study we examined circadian behavioral and electrophysiological changes in a mouse model of AD, using male mice from the Tg-SwDI line which expresses human amyloid precursor protein with the familial Swedish (K670N/M671L), Dutch (E693Q), Iowa (D694N) mutations...
March 11, 2018: Neurobiology of Disease
Jaebong Jang, Sooyoung Chung, Youjeong Choi, Hye Young Lim, Yeongeon Son, Sung Kook Chun, Gi Hoon Son, Kyungjin Kim, Young-Ger Suh, Jong-Wha Jung
AIMS: We have previously identified a chemical scaffold possessing 2-ethoxypropanoic acid (designated as KS15) that directly binds to the C-terminal region of cryptochromes (CRYs: CRY1 and CRY2) and enhances E-box-mediated transcription. However, it is still unclear how KS15 impairs the feedback actions of the CRYs and which chemical moieties are functionally important for its actions. MAIN METHODS: The E-box-mediated transcriptional activities were mainly used to examine the effects of KS15 and its derivatives...
March 10, 2018: Life Sciences
Kilmer S McCully
The indoleamine hormone melatonin is synthesized by the pineal gland, controls circadian rhythm, and is dependent upon adenosyl methionine for enzymatic synthesis of melatonin from N-acetyl serotonin. Pineal melatonin secretion declines dramatically with aging and dementia. Elevated plasma homocysteine is a risk factor for atherosclerosis and Alzheimer's disease, and the marked decline in adenosyl methionine with aging leads to dysregulation of methionine metabolism and hyperhomocysteinemia. Thioretinaco ozonide is a disulfonium complex formed from thioretinamide, cobalamin, and ozone, which binds the alpha and gamma-phosphate groups of adenosine triphosphate (ATP) and oxygen in the process of oxidative phosphorylation within mitochondria...
January 2018: Annals of Clinical and Laboratory Science
Fern Jaspers-Fayer, Sarah Yao Lin, Laura Belschner, Janet Mah, Elaine Chan, Clare Bleakley, Rhonda Ellwyn, Annie Simpson, Katherine McKenney, S Evelyn Stewart
BACKGROUND: Sleep disturbances, including delayed sleep phase disorder (DSPD) and disorders of sleep initiation and maintenance (DIMS), have repeatedly been identified in adult obsessive-compulsive disorder (OCD). These disturbances have not been well-characterized objectively in pediatric OCD. METHODS: Thirty OCD-affected youth (8-18 yrs, 40% male) and 30 age and gender-matched healthy controls (HCs) completed the Sleep Disturbances Scale for Children (SDSC), and one week of continuous actigraphy with concurrent sleep diary documentation...
February 23, 2018: Journal of Anxiety Disorders
I Cundrle, P Suk, V Sramek, Z Lacinova, M Haluzik
Physiologically, leptin concentration is controlled by circadian rhythm. However, in critically ill patients, circadian rhythm is disrupted. Thus we hypothesized that circadian leptin concentration changes are not preserved in critically ill patients. Ten consecutive critically ill heart failure patients with the clinical indication for mechanical ventilation and sedation were included into our study. Plasma leptin concentration was measured every 4 h during the first day (0-24 h) and during the third day (48-72 h) after admission...
March 12, 2018: Physiological Research
Ji-Liang Zhang, Min Liu, Chun-Nuan Zhang, Er-Chao Li, Ming-Zhen Fan, Mao-Xian Huang
The brain of fish displays sexual dimorphisms and exhibits remarkable sexual plasticity throughout their life span. Although reproductive toxicity of tributyltin (TBT) in fish is well documented in fish, it remains unknown whether TBT interrupts sexual dimorphisms of fish brains. In this work, brain transcriptomic profiles of rare minnow (Gobiocypris rarus) was characterized and sex-biased genes were identified using RNA sequencing. Functional annotation and enrichment analysis were performed to reveal differences of gene products and pathways between the brains of male and female fish...
March 7, 2018: Ecotoxicology and Environmental Safety
Kieron D Edwards, Naoki Takata, Mikael Johansson, Manuela Jurca, Ondřej Novák, Eva Hényková, Silvia Liverani, Iwanka Kozarewa, Miroslav Strnad, Andrew J Millar, Karin Ljung, Maria E Eriksson
Trees are carbon dioxide sinks and major producers of terrestrial biomass with distinct seasonal growth patterns. Circadian clocks enable the co-ordination of physiological and biochemical temporal activities, optimally regulating multiple traits including growth. To dissect the clock's role in growth, we analysed Populus tremula × P. tremuloides trees with impaired clock function due to down-regulation of central clock components. late elongated hypocotyl (lhy-10) trees, in which expression of LHY1 and LHY2 is reduced by RNAi, have a short free-running period and show disrupted temporal regulation of gene expression and reduced growth, producing 30-40% less biomass than wild-type trees...
March 8, 2018: Plant, Cell & Environment
Anna Ashton, Patrick N Stoney, Jemma Ransom, Peter McCaffery
Vitamin A is important for the circadian timing system; deficiency disrupts daily rhythms in activity and clock gene expression, and reduces the nocturnal peak in melatonin in the pineal gland. However, it is currently unknown how these effects are mediated. Vitamin A primarily acts via the active metabolite, retinoic acid (RA), a transcriptional regulator with emerging non-genomic activities. We investigated whether RA is subject to diurnal variation in synthesis and signaling in the rat pineal gland. Its involvement in two key molecular rhythms in this gland was also examined: kinase activation and induction of Aanat, which encodes the rhythm-generating melatonin synthetic enzyme...
March 8, 2018: Molecular Neurobiology
Leticia Goni, Dianjianyi Sun, Yoriko Heianza, Tiange Wang, Tao Huang, J Alfredo Martínez, Xiaoyun Shang, George A Bray, Steven R Smith, Frank M Sacks, Lu Qi
PURPOSE: A common variant of the melatonin receptor 1B (MTNR1B) gene has been related to increased signaling of melatonin, a hormone previously associated with body fatness mainly through effects on energy metabolism. We examined whether the MTNR1B variant affects changes of body fatness and composition in response to a dietary weight loss intervention. METHODS: The MTNR1B rs10830963 variant was genotyped for 722 overweight and obese individuals, who were randomly assigned to one of four diets varying in macronutrient composition...
March 7, 2018: European Journal of Nutrition
Marcela Valdés-Tovar, Rosa Estrada-Reyes, Héctor Solís-Chagoyán, Jesús Argueta, Ana María Dorantes-Barrón, Daniel Quero-Chávez, Ricardo Cruz-Garduño, Montserrat G Cercós, Citlali Trueta, Julián Oikawa-Sala, Margarita L Dubocovich, Gloria Benítez-King
Mood disorders are a spectrum of neuropsychiatric disorders characterized by changes in the emotional state. In particular, major depressive disorder is expected to have a worldwide prevalence of 20% in 2020, representing a huge socioeconomic burden. Currently used antidepressant drugs have poor efficacy with only 30% of the patients getting in remission after the first-line of treatment. Importantly, mood disorder patients present uncoupling of circadian rhythms. In this regard, melatonin (5-methoxy-N-acetyltryptamine) an indolamine synthesized by the pineal gland during the night, contributes to synchronize body rhythms with the environmental light/dark cycle...
March 7, 2018: British Journal of Pharmacology
Zvonimir Marelja, Silke Leimkühler, Fanis Missirlis
Iron sulfur (Fe-S) clusters and the molybdenum cofactor (Moco) are present at enzyme sites, where the active metal facilitates electron transfer. Such enzyme systems are soluble in the mitochondrial matrix, cytosol and nucleus, or embedded in the inner mitochondrial membrane, but virtually absent from the cell secretory pathway. They are of ancient evolutionary origin supporting respiration, DNA replication, transcription, translation, the biosynthesis of steroids, heme, catabolism of purines, hydroxylation of xenobiotics, and cellular sulfur metabolism...
2018: Frontiers in Physiology
Chiara Tesoriero, Yuan-Zhong Xu, Dieudonné Mumba Ngoyi, Marina Bentivoglio
Trypanosoma brucei ( T. b. ) gambiense is the parasite subspecies responsible for most reported cases of human African trypanosomiasis (HAT) or sleeping sickness. This severe infection leads to characteristic disruption of the sleep-wake cycle, recalling attention on the circadian timing system. Most animal models of the disease have been hitherto based on infection of laboratory rodents with the T. b. brucei subspecies, which is not infectious to humans. In these animal models, functional, rather than structural, alterations of the master circadian pacemaker, the hypothalamic suprachiasmatic nucleus (SCN), have been reported...
2018: Frontiers in Neuroanatomy
Thomas W Hopwood, Sarah Hall, Nicola Begley, Ruth Forman, Sheila Brown, Ryan Vonslow, Ben Saer, Matthew C Little, Emma A Murphy, Rebecca J Hurst, David W Ray, Andrew S MacDonald, Andy Brass, David A Bechtold, Julie E Gibbs, Andrew S Loudon, Kathryn J Else
Resistance to the intestinal parasitic helminth Trichuris muris requires T-helper 2 (TH 2) cellular and associated IgG1 responses, with expulsion typically taking up to 4 weeks in mice. Here, we show that the time-of-day of the initial infection affects efficiency of worm expulsion, with strong TH 2 bias and early expulsion in morning-infected mice. Conversely, mice infected at the start of the night show delayed resistance to infection, and this is associated with feeding-driven metabolic cues, such that feeding restriction to the day-time in normally nocturnal-feeding mice disrupts parasitic expulsion kinetics...
February 28, 2018: Scientific Reports
Oren Froy, Marta Garaulet
Obesity is a major risk factor for the development of illnesses, such as insulin resistance and hypertension and has become a serious public health problem. Mammals have developed a circadian clock located in the hypothalamic suprachiasmatic nuclei (SCN) that responds to the environmental light-dark cycle. Clocks similar to the one located in the SCN are found in peripheral tissues, such as the kidney, liver and adipose tissue. The circadian clock regulates metabolism and energy homeostasis in peripheral tissues by mediating activity and/or expression of key metabolic enzymes and transport systems...
February 27, 2018: Endocrine Reviews
Jennifer Gile, Benjamin Scott, Tobias Eckle
OBJECTIVES: Delirium occurs in approximately 30% of critically ill patients, and the risk of dying during admission doubles in those patients. Molecular mechanisms causing delirium are largely unknown. However, critical illness and the ICU environment consistently disrupt circadian rhythms, and circadian disruptions are strongly associated with delirium. Exposure to benzodiazepines and constant light are suspected risk factors for the development of delirium. Thus, we tested the functional role of the circadian rhythm protein Period 2 (PER2) in different mouse models resembling delirium...
February 27, 2018: Critical Care Medicine
Kelly C Allison, Namni Goel
Timing of eating is recognized as a significant contributor to body weight regulation. Disruption of sleep-wake cycles from a predominantly diurnal (daytime) to a delayed (evening) lifestyle leads to altered circadian rhythms and metabolic dysfunction. This article reviews current evidence for timed and delayed eating in individuals of normal weight and those with overweight or obesity: some findings indicate a benefit of eating earlier in the daytime on weight and/or metabolic outcomes, although the findings have not been uniformly consistent, and more rigorous and longer-duration studies are needed...
February 24, 2018: Physiology & Behavior
Angus S Fisk, Shu K E Tam, Laurence A Brown, Vladyslav V Vyazovskiy, David M Bannerman, Stuart N Peirson
Light exerts a wide range of effects on mammalian physiology and behavior. As well as synchronizing circadian rhythms to the external environment, light has been shown to modulate autonomic and neuroendocrine responses as well as regulating sleep and influencing cognitive processes such as attention, arousal, and performance. The last two decades have seen major advances in our understanding of the retinal photoreceptors that mediate these non-image forming responses to light, as well as the neural pathways and molecular mechanisms by which circadian rhythms are generated and entrained to the external light/dark (LD) cycle...
2018: Frontiers in Neurology
Leila M Guissoni Campos, Alessandre Hataka, Isis Z Vieira, Rogério L Buchaim, Isadora F Robalinho, Giovanna E P S Arantes, Joyce S Viégas, Henrique Bosso, Rafael M Bravos, Luciana Pinato
Oscillations of brain proteins in circadian rhythms are important for determining several cellular and physiological processes in anticipation of daily and seasonal environmental rhythms. In addition to the suprachiasmatic nucleus, the primary central oscillator, the cerebellum shows oscillations in gene and protein expression. The variety of local circuit rhythms that the cerebellar cortex contains influences functions such as motivational processes, regulation of feeding, food anticipation, language, and working memory...
2018: Frontiers in Physiology
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