A5035527770- Circadian rhythm and melatonin
- Dietary Effects on Health
- Adipose Tissue and Metabolism
- Spaceflight effects on biology
- Diet and metabolism studies
- Genetics, Aging, and Longevity in Model Organisms
- Sleep and Wakefulness Research
- Sleep and related disorders
- Metabolomics and Mass Spectrometry Studies
- Light effects on plants
- Regulation of Appetite and Obesity
- Psychological and Temporal Perspectives Research
- Birth, Development, and Health
- Neurobiology and Insect Physiology Research
- Lipoproteins and Cardiovascular Health
- Natural Language Processing Techniques
- Nutritional Studies and Diet
- Topic Modeling
- Receptor Mechanisms and Signaling
- Muscle metabolism and nutrition
- Electromagnetic Fields and Biological Effects
- Biochemical Analysis and Sensing Techniques
- Ruminant Nutrition and Digestive Physiology
- Plant biochemistry and biosynthesis
- Phytase and its Applications
University of Surrey
2016-2025
University of Aberdeen
2003-2022
Indiana University Bloomington
2002-2015
University of Manchester
1956-2003
University of Nottingham
2003
McGill University
1976
Bellevue Hospital Center
1976
Although daily rhythms regulate multiple aspects of human physiology, rhythmic control the metabolome remains poorly understood. The primary objective this proof-of-concept study was identification metabolites in plasma that exhibit significant 24-h variation. This assessed via an untargeted metabolomic approach using liquid chromatography–mass spectrometry (LC-MS). Eight lean, healthy, and unmedicated men, mean age 53.6 (SD ± 6.0) yrs, maintained a fixed sleep/wake schedule dietary regime...
Abstract This pilot study explored the feasibility of a moderate time-restricted feeding (TRF) intervention and its effects on adiposity metabolism. For 10 weeks, free-living TRF group delayed breakfast advanced dinner by 1·5 h each. Changes in dietary intake, fasting biochemistry (glucose, insulin, lipids) were compared with controls who maintained habitual patterns. Thirteen participants (29 ( sem 2) kg/m 2 ) completed study. The average daily interval was successfully reduced (743 32) to...
Study Objectives:To screen the PER3 promoter for polymorphisms and investigate phenotypic associations of these with diurnal preference, delayed sleep phase disorder/syndrome (DSPD/DSPS), their effects on reporter gene expression.
Circadian regulation of transcriptional processes has a broad impact on cell metabolism. Here, we compared the diurnal transcriptome human skeletal muscle conducted serial biopsies in vivo with profiles myotubes synchronized vitro. More extensive rhythmic transcription was observed to vitro culture as large part mRNA rhythmicity lost siRNA-mediated clock disruption primary significantly affected expression ~8% all genes, glucose homeostasis and lipid Genes involved GLUT4 expression,...
Significance Our experiments provide the analysis of lipid metabolite circadian oscillations in a cellular system synchronized vitro, suggesting cell-autonomous diurnal changes profiles independent feeding. Moreover, our work represents comprehensive comparison between composition human skeletal muscle derived from sedentary healthy adults, receiving hourly isocaloric solutions, and primary myotubes cultured vitro. A substantial number metabolites, particular membrane lipids, exhibited...
Abstract Studying circadian rhythms in most human tissues is hampered by difficulty collecting serial samples. Here we reveal the transcriptome and metabolic pathways of white adipose tissue. Subcutaneous tissue was taken from seven healthy males under highly controlled ‘constant routine’ conditions. Five biopsies per participant were at six-hourly intervals for microarray analysis silico integrative modelling. We identified 837 transcripts exhibiting expression profiles (2% 41619 transcript...
Previous animal studies suggest a functional relationship between metabolism, type 2 diabetes, and the amplitude of daily rhythms in white adipose tissue (WAT). However, data interpretation is confounded by differences genetic background diet or limited sampling points. We have taken novel approach analyzing serial human WAT biopsies across 24-h cycle controlled laboratory conditions.Lean (n = 8), overweight/obese 11), diabetic 8) volunteers followed strict sleep-wake dietary regimen for 1...
At temperate latitudes, increases in day length the spring promote summer phenotype. In mammals, this long-day response is mediated by decreasing nightly duration of melatonin secretion pineal gland. This affects adenylate cyclase signal transduction and clock gene expression melatonin-responsive cells pars tuberalis pituitary, which control seasonal prolactin secretion. To define photoperiodic limits mammalian long response, we transferred short (8 h light per 24 h) acclimated Soay sheep to...
Melatonin and leptin exhibit daily rhythms that may contribute towards changes in metabolic physiology. It remains unclear, however, whether this rhythmicity is altered obesity or type 2 diabetes (T2DM). We tested the hypothesis 24-hour profiles of melatonin, mRNA are by status laboratory conditions. Men between 45–65 years old were recruited into lean, obese-non-diabetic obese-T2DM groups. Volunteers followed strict sleep-wake dietary regimes for 1 week before study. They then maintained...
Abstract A growing body of evidence highlights the importance biological clock as a modulator energy balance and metabolism. Recent studies in humans have shown that ingested calories are apparently utilised more efficiently morning than evening this is manifest through improved weight loss, even under iso‐energetic calorie intake. The mechanisms behind enhanced metabolism not yet clear, although it may result from behavioural adaptations or circadian driven variations physiology major...
Metabolic profiling of individuals with type 2 diabetes mellitus (T2DM) has previously been limited to single-time-point samples, ignoring time-of-day variation. Here, we tested our hypothesis that body mass and T2DM affect daily rhythmicity concentrations circulating metabolites across a 24-h day in 3 age-matched, male groups-lean, overweight/obese (OW/OB), OW/OB T2DM-in controlled laboratory conditions, which were not confounded by large meals. By using targeted liquid chromatography/mass...
In mammals, changing day length modulates endocrine rhythms via nocturnal melatonin secretion. Studies of the pituitary pars tuberalis (PT) suggest that melatonin-regulated clock gene expression is critical to this process. Here, we considered whether continue in PT absence and effects on these genes are temporally gated. Soay sheep acclimated long photoperiod (LP) were transferred constant light for 24 h, suppressing endogenous Animals infused with at 4-h intervals across final killed 3 h...
Abstract In seasonal animals, prolonged exposure to constant photoperiod induces photorefractoriness, causing spontaneous reversion in physiology that of the previous photoperiodic state. This study tested hypothesis onset photorefractoriness is correlated with a change circadian expression clock genes suprachiasmatic nucleus (circadian pacemaker) and pars tuberalis (PT, melatonin target tissue). Soay sheep were exposed summer (16-h light) for either 6 or 30 wk produce photostimulated...
Abstract Photoperiod regulates the seasonal physiology of many mammals living in temperate latitudes. Photoperiodic information is decoded by master circadian clock suprachiasmatic nuclei (SCN) hypothalamus and then transduced via pineal melatonin secretion. This neurochemical signal interpreted tissues expressing receptors (e.g. pituitary pars tuberalis, PT) to drive physiological changes. In this study we analysed photoperiodic regulation clockwork SCN PT Siberian hamster. Female hamsters...
We compared the period of rhythm plasma melatonin, driven by hypothalamic circadian pacemaker, to in vitro periodicity cultured peripheral fibroblasts assess effects on these rhythms a polymorphism PER3 (rs57875989), which is associated with sleep timing. In was determined using luminometry fibroblasts, expression firefly luciferase promoter gene Arntl (Bmal1). The melatonin assessed 9-d forced desynchrony protocol, minimizing confounding sleep-wake and light-dark cycles rhythmicity. periods...
Summary Sleep complaints and irregular sleep patterns, such as curtailed during workdays longer later weekends, are common. It is often implied that differences in circadian period entrained phase contribute to these but few data available. We assessed parameters of the rhythm melatonin at baseline a forced desynchrony protocol 35 participants (18 women) with no disorders. Circadian varied between 23 h 50 min 24 31 min, correlated positively ( n = 31, r s 0.43, P 0.017) timing relative...