scholarly journals The Lack of Light-Dark and Feeding-Fasting Cycles Alters Temporal Events in the Goldfish (Carassius auratus) Stress Axis

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 669
Author(s):  
Nuria Saiz ◽  
Miguel Gómez-Boronat ◽  
Nuria De Pedro ◽  
María Jesús Delgado ◽  
Esther Isorna
Keyword(s):  
Clock Gene ◽  
Environmental Changes ◽  
Clock Genes ◽  
Stress Axis ◽  
Constant Darkness ◽  
Dark Cycle ◽  
Goldfish Carassius Auratus ◽  
Clock Gene Expression ◽  
Temporal Events ◽  
Cortisol Release

Vertebrates possess circadian clocks, driven by transcriptional–translational loops of clock genes, to orchestrate anticipatory physiological adaptations to cyclic environmental changes. This work aims to investigate how the absence of a light-dark cycle and a feeding schedule impacts the oscillators in the hypothalamus-pituitary-interrenal axis of goldfish. Fish were maintained under 12L:12D feeding at ZT 2; 12L:12D feeding at random times; and constant darkness feeding at ZT 2. After 30 days, fish were sampled to measure daily variations in plasma cortisol and clock gene expression in the hypothalamus-pituitary-interrenal (HPI) axis. Clock gene rhythms in the HPI were synchronic in the presence of a light-dark cycle but were lost in its absence, while in randomly fed fish, only the interrenal clock was disrupted. The highest cortisol levels were found in the randomly fed group, suggesting that uncertainty of food availability could be as stressful as the absence of a light-dark cycle. Cortisol daily rhythms seem to depend on central clocks, as a disruption in the adrenal clock did not impede rhythmic cortisol release, although it could sensitize the tissue to stress.

scholarly journals DEC1 Modulates the Circadian Phase of Clock Gene Expression

2008 ◽  
Vol 28 (12) ◽  
pp. 4080-4092 ◽  
Author(s):  
Ayumu Nakashima ◽  
Takeshi Kawamoto ◽  
Kiyomasa K. Honda ◽  
Taichi Ueshima ◽  
Mitsuhide Noshiro ◽  
...  
Keyword(s):  
Gene Expression ◽  
Clock Genes ◽  
Luciferase Reporter ◽  
Constant Darkness ◽  
Mobility Shift ◽  
Behavioral Rhythms ◽  
Circadian Phase ◽  
Clock Gene Expression ◽  
E Box ◽  
E Boxes

ABSTRACT DEC1 suppresses CLOCK/BMAL1-enhanced promoter activity, but its role in the circadian system of mammals remains unclear. Here we examined the effect of Dec1 overexpression or deficiency on circadian gene expression triggered with 50% serum. Overexpression of Dec1 delayed the phase of clock genes such as Dec1, Dec2, Per1, and Dbp that contain E boxes in their regulatory regions, whereas it had little effect on the circadian phase of Per2 and Cry1 carrying CACGTT E′ boxes. In contrast, Dec1 deficiency advanced the phase of the E-box-containing clock genes but not that of the E′-box-containing clock genes. Accordingly, DEC1 showed strong binding and transrepression on the E box, but not on the E′ box, in chromatin immunoprecipitation, electrophoretic mobility shift, and luciferase reporter assays. Dec1 −/− mice showed behavioral rhythms with slightly but significantly longer circadian periods under conditions of constant darkness and faster reentrainment to a 6-h phase-advanced shift of a light-dark cycle. Knockdown of Dec2 with small interfering RNA advanced the phase of Dec1 and Dbp expression, and double knockdown of Dec1 and Dec2 had much stronger effects on the expression of the E-box-containing clock genes. These findings suggest that DEC1, along with DEC2, plays a role in the finer regulation and robustness of the molecular clock.

scholarly journals Clock gene expression is altered in veterans with sleep apnea

2019 ◽  
Vol 51 (3) ◽  
pp. 77-82 ◽  
Author(s):  
Muna T. Canales ◽  
Meaghan Holzworth ◽  
Shahab Bozorgmehri ◽  
Areef Ishani ◽  
I. David Weiner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sleep Apnea ◽  
Clock Gene ◽  
Clock Genes ◽  
Apnea Hypopnea Index ◽  
Blood Collection ◽  
Cross Sectional ◽  
Sleep Complaints ◽  
Clock Gene Expression ◽  
Metabolic Outcomes

Clock gene dysregulation has been shown to underlie various sleep disorders and may lead to negative cardio-metabolic outcomes. However, the association between sleep apnea (SA) and core clock gene expression is unclear. We performed a cross-sectional analysis of 49 Veterans enrolled in a study of SA outcomes in veterans with chronic kidney disease, not selected for SA or sleep complaints. All participants underwent full polysomnography and next morning whole blood collection for clock gene expression. We defined SA as an apnea-hypopnea index ≥15 events/h; nocturnal hypoxemia(NH) was defined as ≥10% of total sleep time spent at <90% oxygen saturation. We used quantitative real-time PCR to compare the relative gene expression of clock genes between those with and without SA or NH. Clock genes studied were Bmal1, Ck1δ, Ck1ε, Clock, Cry1, Cry2, NPAS2, Per1, Per2, Per3, Rev-Erb-α, RORα, and Timeless. Our cohort was 90% male, mean age was 71 yr (SD 11), mean body mass index was 30 kg/m2 (SD 5); 41% had SA, and 27% had NH. Compared with those without SA, Per3 expression was reduced by 35% in SA ( P = 0.027). Compared with those without NH, NPAS2, Per1, and Rev-Erb-α expression was reduced in NH (50.4%, P = 0.027; 28.7%, P = 0.014; 31%, P = 0.040, respectively). There was no statistical difference in expression of the remaining clock genes by SA or NH status. Our findings suggest that SA or related NH and clock gene expression may be interrelated. Future study of 24 h clock gene expression in SA is needed to establish the role of clock gene regulation on the pathway between SA and cardio-metabolic outcomes.

Clock Gene Expression in the Submandibular Glands

2005 ◽  
Vol 84 (12) ◽  
pp. 1193-1197 ◽  
Author(s):  
M. Furukawa ◽  
T. Kawamoto ◽  
M. Noshiro ◽  
K.K. Honda ◽  
M. Sakai ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Clock Gene ◽  
Clock Genes ◽  
Expression Profiles ◽  
Mrna Levels ◽  
Peripheral Tissues ◽  
Submandibular Glands ◽  
Circadian Expression ◽  
Clock Gene Expression

Clock genes, which mediate molecular circadian rhythms, are expressed in a circadian fashion in the suprachiasmatic nucleus and in various peripheral tissues. To establish a molecular basis for circadian regulation in the salivary glands, we examined expression profiles of clock-related genes and salivary gland-characteristic genes. Clock-related genes—including Per1, Per2, Cry1, Bmal1, Dec1, Dec2, Dbp, and Reverbα—showed robust circadian expression rhythms in the submandibular glands in 12:12-hour light-dark conditions. In addition, a robust circadian rhythm was observed in amylase 1 mRNA levels, whereas the expression of other salivary-gland-characteristic genes examined was not rhythmic. The Clock mutation resulted in increased or decreased mRNA levels of Per2, Bmal1, Dec1, Dec2, and Dbp, and in Cry1− /− background, Cry2 disruption also increased or decreased mRNA levels of these clock-related genes and the amylase 1 gene. These findings indicate that the Clock- and Cry-dependent molecular clock system is active in the salivary glands.

scholarly journals Physiology of Circadian Entrainment

2010 ◽  
Vol 90 (3) ◽  
pp. 1063-1102 ◽  
Author(s):  
Diego A. Golombek ◽  
Ruth E. Rosenstein
Keyword(s):  
Circadian Rhythms ◽  
Clock Gene ◽  
Retinal Diseases ◽  
Suprachiasmatic Nuclei ◽  
Circadian Variations ◽  
Dark Cycle ◽  
Clock Gene Expression ◽  
Biological Oscillators ◽  
Pituitary Adenylate Cyclase ◽  
Neurotransmitter Glutamate

Mammalian circadian rhythms are controlled by endogenous biological oscillators, including a master clock located in the hypothalamic suprachiasmatic nuclei (SCN). Since the period of this oscillation is of ∼24 h, to keep synchrony with the environment, circadian rhythms need to be entrained daily by means of Zeitgeber (“time giver”) signals, such as the light-dark cycle. Recent advances in the neurophysiology and molecular biology of circadian rhythmicity allow a better understanding of synchronization. In this review we cover several aspects of the mechanisms for photic entrainment of mammalian circadian rhythms, including retinal sensitivity to light by means of novel photopigments as well as circadian variations in the retina that contribute to the regulation of retinal physiology. Downstream from the retina, we examine retinohypothalamic communication through neurotransmitter (glutamate, aspartate, pituitary adenylate cyclase-activating polypeptide) interaction with SCN receptors and the resulting signal transduction pathways in suprachiasmatic neurons, as well as putative neuron-glia interactions. Finally, we describe and analyze clock gene expression and its importance in entrainment mechanisms, as well as circadian disorders or retinal diseases related to entrainment deficits, including experimental and clinical treatments.

scholarly journals Poor Sleep Quality Is Associated with Dawn Phenomenon and Impaired Circadian Clock Gene Expression in Subjects with Type 2 Diabetes Mellitus

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yuxin Huang ◽  
Haidong Wang ◽  
Yuan Li ◽  
Xiaoming Tao ◽  
Jiao Sun
Keyword(s):  
Sleep Quality ◽  
Circadian Clock ◽  
Clock Gene ◽  
Clock Genes ◽  
Poor Sleep ◽  
Poor Sleep Quality ◽  
Clock Gene Expression ◽  
Dawn Phenomenon ◽  
Circadian Clock Genes ◽  
Good Sleep

Aims. We investigated whether poor sleep quality is associated with both dawn phenomenon and impaired circadian clock gene expression in subjects with diabetes. Methods. 81 subjects with diabetes on continuous glucose monitoring were divided into two groups according to the Pittsburgh Sleep Quality Index. The magnitude of dawn phenomenon was quantified by its increment from nocturnal nadir to prebreakfast. Peripheral leucocytes were sampled from 81 subjects with diabetes and 28 normal controls at 09:00. Transcript levels of circadian clock genes (BMAL1, PER1, PER2, and PER3) were determined by real-time quantitative polymerase chain reaction. Results. The levels of HbA1c and fasting glucose and the magnitude of dawn phenomenon were significantly higher in the diabetes group with poor sleep quality than that with good sleep quality. Peripheral leucocytes from subjects with poor sleep quality expressed significantly lower transcript levels of BMAL1 and PER1 compared with those with good sleep quality. Poor sleep quality was significantly correlated with magnitude of dawn phenomenon. Multiple linear regression showed that sleep quality and PER1 were significantly independently correlated with dawn phenomenon. Conclusions. Dawn phenomenon is associated with sleep quality. Furthermore, mRNA expression of circadian clock genes is dampened in peripheral leucocytes of subjects with poor sleep quality.

scholarly journals Clock Gene Expression in Adult Primate Suprachiasmatic Nuclei and Adrenal: Is the Adrenal a Peripheral Clock Responsive to Melatonin?

Endocrinology ◽  
2008 ◽  
Vol 149 (4) ◽  
pp. 1454-1461 ◽  
Author(s):  
F. J. Valenzuela ◽  
C. Torres-Farfan ◽  
H. G. Richter ◽  
N. Mendez ◽  
C. Campino ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Clock Gene ◽  
Clock Genes ◽  
Phase Relationship ◽  
Suprachiasmatic Nuclei ◽  
Rhythmic Expression ◽  
Peripheral Oscillators ◽  
Clock Gene Expression ◽  
Timing System ◽  
Circadian Timing System

The circadian production of glucocorticoids involves the concerted action of several factors that eventually allow an adequate adaptation to the environment. Circadian rhythms are controlled by the circadian timing system that comprises peripheral oscillators and a central rhythm generator located in the suprachiasmatic nucleus (SCN) of the hypothalamus, driven by the self-regulatory interaction of a set of proteins encoded by genes named clock genes. Here we describe the phase relationship between the SCN and adrenal gland for the expression of selected core clock transcripts (Per-2, Bmal-1) in the adult capuchin monkey, a New World, diurnal nonhuman primate. In the SCN we found a higher expression of Bmal-1 during the h of darkness (2000–0200 h) and Per-2 during daytime h (1400 h). The adrenal gland expressed clock genes in oscillatory fashion, with higher values for Bmal-1 during the day (1400–2000 h), whereas Per-2 was higher at nighttime (about 0200 h), resulting in a 9- to 12-h antiphase pattern. In the adrenal gland, the oscillation of clock genes was accompanied by rhythmic expression of a functional output, the steroidogenic enzyme 3β-hydroxysteroid dehydrogenase. Furthermore, we show that adrenal explants maintained oscillatory expression of Per-2 and Bmal-1 for at least 36 h in culture. The acrophase of both transcripts, but not its overall expression along the incubation, was blunted by 100 nm melatonin. Altogether, these results demonstrate oscillation of clock genes in the SCN and adrenal gland of a diurnal primate and support an oscillation of clock genes in the adrenal gland that may be modulated by the neurohormone melatonin.

scholarly journals P144 Clock gene expression levels inversely correlate with disease activity in ulcerative colitis and Crohn’s disease

2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S228-S228
Author(s):  
Y Weintraub ◽  
S Cohen ◽  
N Chapnik ◽  
A Anafy ◽  
A Yerushalmy-Feler ◽  
...  
Keyword(s):  
Gene Expression ◽  
Ulcerative Colitis ◽  
Crohn’S Disease ◽  
Disease Activity ◽  
Clock Gene ◽  
Clock Genes ◽  
Clinical Status ◽  
Expression Levels ◽  
Clock Gene Expression ◽  
Gene Expression Levels

Abstract Background Pathophysiological mechanisms active in inflammatory bowel disease (IBD), such as mucosal barrier repair, innate and adaptive immune responses, intestinal motility and gut microbiome, all exhibit diurnal variations. Chronic disruption of the molecular clock augment inflammatory response. We have shown that newly diagnosed, naïve to treatment, young IBD patients showed reduced clock gene expression in both inflamed and non-inflamed intestinal tissues and in peripheral White Blood Cells (WBC). This reduction correlated with disease activity. Our aim in this study was to determine whether certain clock genes correlate with disease activity scores or inflammatory markers in Crohn’s disease (CD) vs. ulcerative colitis (UC). Methods 17 patients with CD and 13 with UC, 8–22 years old, were recruited. Patients were evaluated upon diagnosis and during medical treatment. Disease activity scores, C-reactive protein (CRP) and fecal calprotectin (Fcal) levels were measured and WBC were analysed for clock gene (CLOCK, BMAL1, CRY1, CRY2, PER1 and PER2) expression. Clock gene expression levels were correlated to disease activity scores (clinically active vs. remission), CRP levels (&lt;5 mg/l vs. &gt;5 mg/l) and Fcal levels (&lt; 250 μg/mg vs. &gt;250 μg/mg) in CD (21 samples) and UC (20 samples). Results In UC, BMAL (p&lt;0.008), CLOCK (p&lt;0.02), CRY1 (p&lt;0.002), CRY2 (p&lt;0.0009), PER1 (p&lt;0.003) and PER2 (p&lt;0.003) showed decreased expression when Fcal levels were &gt; 250 μg/mg. When compared with the clinical status and CRP levels, only BMAL1 showed reduced expression (p&lt;0.003 and p&lt;0.001, respectively). In CD, clinical status correlated with clock gene expression: CLOCK (p&lt;0.035), PER1 (p&lt;0.001) and CRY1 (p&lt;0.028) were reduced in active disease. CRP and Fcal did not correlate with clock gene expression. Conclusion Altered levels of certain clock genes were demonstrated in young CD and UC patients in exacerbation vs. remission. In UC, Fcal levels inversely correlated with all major circadian genes and partially with clinical status and CRP levels. In CD patients clock gene expression inversely correlated with clinical status.

scholarly journals Neuron-specific knockouts indicate the importance of network communication to Drosophila rhythmicity

2019 ◽  
Author(s):  
M Schlichting ◽  
MM Diaz ◽  
J Xin ◽  
M Rosbash
Keyword(s):  
Gene Expression ◽  
Circadian Rhythms ◽  
Intercellular Communication ◽  
Clock Gene ◽  
Feedback Loops ◽  
Neuronal Firing ◽  
Network Communication ◽  
Constant Darkness ◽  
Circadian Period ◽  
Clock Gene Expression

AbstractAnimal circadian rhythms persist in constant darkness and are driven by intracellular transcription-translation feedback loops. Although these cellular oscillators communicate, isolated mammalian cellular clocks continue to tick away in darkness without intercellular communication. To investigate these issues in Drosophila, we assayed behavior as well as molecular rhythms within individual brain clock neurons while blocking communication within the ca. 150 neuron clock network. We also generated CRISPR-mediated neuron-specific circadian clock knockouts. The results point to two key clock neuron groups: loss of the clock within both regions but neither one alone has a strong behavioral phenotype in darkness; communication between these regions also contributes to circadian period determination. Under these dark conditions, the clock within one region persists without network communication. The clock within the famous PDF-expressing s-LNv neurons however was strongly dependent on network communication, likely because clock gene expression within these vulnerable sLNvs depends on neuronal firing or light.

scholarly journals Differential Expression of Circadian Clock Genes in the Bovine Neuroendocrine Adrenal System

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A66-A67
Author(s):  
Audrey L Earnhardt ◽  
David G Riley ◽  
Noushin Ghaffari ◽  
Penny K Riggs ◽  
Charles R Long ◽  
...  
Keyword(s):  
Gene Expression ◽  
Circadian Clock ◽  
Clock Gene ◽  
Target Genes ◽  
Clock Genes ◽  
Expression Profiles ◽  
Primary Objective ◽  
Clock Gene Expression ◽  
Adrenal System ◽  
Circadian Clock Genes

Abstract The primary objective of this investigation was to determine whether circadian clock genes were differentially expressed within or among bovine hypothalamic paraventricular nucleus (PVN), anterior pituitary gland (AP), adrenocortical (AC) and adrenomedullary (AM) tissues. The PVN, AP, AC, and AM were isolated from 5-yr-old Brahman cows (n = 8) harvested humanely at an abattoir between 0800-1100 h. Expression of target genes in each sample was evaluated via RNA-sequencing analyses. Gene counts were normalized using the trimmed mean of M values (TMM) method in the edgeR Package from Bioconductor, R. The normalized gene counts of genes important for circadian rhythm were statistically analyzed using the GLM Procedure of SAS. The genes analyzed were circadian locomotor output cycles protein kaput (CLOCK), cryptochrome circadian regulator 1 and 2 (CRY1 and CRY2), aryl hydrocarbon receptor nuclear translocator like (ARNTL), period circadian regulator 1 and 2 (PER1 and PER2), neuronal PAS domain protein 2 (NPAS2), and nuclear receptor subfamily 1 group D member 1 (NR1D1). Overall, relative expression profiles of clock genes differed (P &lt; 0.01) within each tissue with PER1 having greater expression in all tissues (P &lt; 0.01). Within the PVN expression of CLOCK, CRY1, ARNTL, and PER2 was less than that of CRY2, NPAS2, and NR1D1 (P &lt; 0.01). In the AP, with the exception of PER1, no other clock gene differed in degree of expression. In the AC, expression of CLOCK and NPAS2 was greater than CRY1, ARNTL, PER2, and NR1D1 (P &lt; 0.05), whereas CRY2 expression exceeded only CRY1 (P &lt; 0.05). Within the AM, CLOCK and CRY2 expression was greater than CRY1 and ARNTL (P &lt; 0.05). Overall, clock gene expression among tissues differed (P &lt; 0.01) for each individual clock gene. The AC and AM had similar clock gene expression, except expression of CRY2 and PER2 was greater in AM (P &lt; 0.05). The AC and AM had greater expression of CLOCK than the PVN and AP (P &lt; 0.01), with PVN having greater expression than AP (P &lt; 0.01). The AP had greater expression of NPAS2, followed by PVN, with the least expression in the AC and AM (P &lt; 0.01). Both PVN and AP had greater CRY1 and NR1D1 expression than AC or AM (P &lt; 0.01). The AP had greater PER1 expression than PVN, AC, and AM (P &lt; 0.01), whereas PVN, AC, and AM had greater ARNTL expression than AP (P &lt; 0.05). Both AP and AM had greater expression of PER2 than PVN or AC (P &lt; 0.01). The PVN had greater expression of CRY2 than the AP, AC, and AM (P &lt; 0.01). These results indicated that within each tissue the various clock genes were expressed in different quantities. Also, the clock genes were expressed differentially among the tissues of the bovine neuroendocrine adrenal system. Temporal relationships of these genes with the primary endocrine products of these tissues should be investigated to define the roles of peripheral clock genes in regulation of metabolism and health.

scholarly journals Rhythms during the polar night: evidence of clock-gene oscillations in the Arctic scallop Chlamys islandica

2020 ◽  
Vol 287 (1933) ◽  
pp. 20201001
Author(s):  
Mickael Perrigault ◽  
Hector Andrade ◽  
Laure Bellec ◽  
Carl Ballantine ◽  
Lionel Camus ◽  
...  
Keyword(s):  
Gene Expression ◽  
Clock Gene ◽  
Clock Genes ◽  
Biological Rhythms ◽  
The Arctic ◽  
Polar Night ◽  
Clock Gene Expression ◽  
Chlamys Islandica ◽  
Autumnal Equinox ◽  
Cyclic Variations

Arctic regions are highly impacted by climate change and are characterized by drastic seasonal changes in light intensity and duration with extended periods of permanent light or darkness. Organisms use cyclic variations in light to synchronize daily and seasonal biological rhythms to anticipate cyclic variations in the environment, to control phenology and to maintain fitness. In this study, we investigated the diel biological rhythms of the Arctic scallop, Chlamys islandica , during the autumnal equinox and polar night. Putative circadian clock genes and putative light perception genes were identified in the Arctic scallop. Clock gene expression oscillated in the three tissues studied (gills, muscle, mantle edge). The oscillation of some genes in some tissues shifted from daily to tidal periodicity between the equinox and polar night periods and was associated with valve behaviour. These results are the first evidence of the persistence of clock gene expression oscillations during the polar night and might suggest that functional clockwork could entrain rhythmic behaviours in polar environments.

Sign in / Sign up

Export Citation Format

Share Document