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van Rosmalen L, Deota S, Maier G, Le HD, Lin T, Ramasamy RK, Hut RA, Panda S. Energy balance drives diurnal and nocturnal brain transcriptome rhythms. Cell Rep 2024; 43:113951. [PMID: 38508192 PMCID: PMC11330649 DOI: 10.1016/j.celrep.2024.113951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 01/30/2024] [Accepted: 02/26/2024] [Indexed: 03/22/2024] Open
Abstract
Plasticity in daily timing of activity has been observed in many species, yet the underlying mechanisms driving nocturnality and diurnality are unknown. By regulating how much wheel-running activity will be rewarded with a food pellet, we can manipulate energy balance and switch mice to be nocturnal or diurnal. Here, we present the rhythmic transcriptome of 21 tissues, including 17 brain regions, sampled every 4 h over a 24-h period from nocturnal and diurnal male CBA/CaJ mice. Rhythmic gene expression across tissues comprised different sets of genes with minimal overlap between nocturnal and diurnal mice. We show that non-clock genes in the suprachiasmatic nucleus (SCN) change, and the habenula was most affected. Our results indicate that adaptive flexibility in daily timing of behavior is supported by gene expression dynamics in many tissues and brain regions, especially in the habenula, which suggests a crucial role for the observed nocturnal-diurnal switch.
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Affiliation(s)
- Laura van Rosmalen
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Shaunak Deota
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Geraldine Maier
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Hiep D Le
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Terry Lin
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Ramesh K Ramasamy
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Roelof A Hut
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC Groningen, the Netherlands.
| | - Satchidananda Panda
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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2
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Hitrec T, Petit C, Cryer E, Muir C, Tal N, Fustin JM, Hughes AT, Piggins HD. Timed exercise stabilizes behavioral rhythms but not molecular programs in the brain's suprachiasmatic clock. iScience 2023; 26:106002. [PMID: 36866044 PMCID: PMC9971895 DOI: 10.1016/j.isci.2023.106002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/25/2022] [Accepted: 01/13/2023] [Indexed: 01/20/2023] Open
Abstract
Timed daily access to a running-wheel (scheduled voluntary exercise; SVE) synchronizes rodent circadian rhythms and promotes stable, 24h rhythms in animals with genetically targeted impairment of neuropeptide signaling (Vipr2 -/- mice). Here we used RNA-seq and/or qRT-PCR to assess how this neuropeptide signaling impairment as well as SVE shapes molecular programs in the brain clock (suprachiasmatic nuclei; SCN) and peripheral tissues (liver and lung). Compared to Vipr2 +/+ animals, the SCN transcriptome of Vipr2 -/- mice showed extensive dysregulation which included core clock components, transcription factors, and neurochemicals. Furthermore, although SVE stabilized behavioral rhythms in these animals, the SCN transcriptome remained dysregulated. The molecular programs in the lung and liver of Vipr2 -/- mice were partially intact, although their response to SVE differed to that of these peripheral tissues in the Vipr2 +/+ mice. These findings highlight that SVE can correct behavioral abnormalities in circadian rhythms without causing large scale alterations to the SCN transcriptome.
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Affiliation(s)
- Timna Hitrec
- School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Cheryl Petit
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK
| | - Emily Cryer
- School of Biological Sciences, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - Charlotte Muir
- School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Natalie Tal
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK
| | - Jean-Michel Fustin
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK
| | - Alun T.L. Hughes
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK,School of Biological and Environmental Sciences, Faculty of Science, Liverpool John Moores University, Liverpool L3 3AF, UK,Corresponding author
| | - Hugh D. Piggins
- School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK,School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK,Corresponding author
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3
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Lower morning levels of cortisol and neuropeptides in blood samples from patients with bipolar disorder. JOURNAL OF AFFECTIVE DISORDERS REPORTS 2022. [DOI: 10.1016/j.jadr.2022.100406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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4
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Kauffman AS. Neuroendocrine mechanisms underlying estrogen positive feedback and the LH surge. Front Neurosci 2022; 16:953252. [PMID: 35968365 PMCID: PMC9364933 DOI: 10.3389/fnins.2022.953252] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 07/08/2022] [Indexed: 01/26/2023] Open
Abstract
A fundamental principle in reproductive neuroendocrinology is sex steroid feedback: steroid hormones secreted by the gonads circulate back to the brain to regulate the neural circuits governing the reproductive neuroendocrine axis. These regulatory feedback loops ultimately act to modulate gonadotropin-releasing hormone (GnRH) secretion, thereby affecting gonadotropin secretion from the anterior pituitary. In females, rising estradiol (E2) during the middle of the menstrual (or estrous) cycle paradoxically "switch" from being inhibitory on GnRH secretion ("negative feedback") to stimulating GnRH release ("positive feedback"), resulting in a surge in GnRH secretion and a downstream LH surge that triggers ovulation. While upstream neural afferents of GnRH neurons, including kisspeptin neurons in the rostral hypothalamus, are proposed as critical loci of E2 feedback action, the underlying mechanisms governing the shift between E2 negative and positive feedback are still poorly understood. Indeed, the precise cell targets, neural signaling factors and receptors, hormonal pathways, and molecular mechanisms by which ovarian-derived E2 indirectly stimulates GnRH surge secretion remain incompletely known. In many species, there is also a circadian component to the LH surge, restricting its occurrence to specific times of day, but how the circadian clock interacts with endocrine signals to ultimately time LH surge generation also remains a major gap in knowledge. Here, we focus on classic and recent data from rodent models and discuss the consensus knowledge of the neural players, including kisspeptin, the suprachiasmatic nucleus, and glia, as well as endocrine players, including estradiol and progesterone, in the complex regulation and generation of E2-induced LH surges in females.
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5
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Caputo R, Poirel VJ, Challet E, Meijer JH, Raison S. Bimodal serotonin synthesis in the diurnal rodent, Arvicanthis ansorgei. FASEB J 2022; 36:e22255. [PMID: 35294080 DOI: 10.1096/fj.202101726r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/05/2022] [Accepted: 03/04/2022] [Indexed: 11/11/2022]
Abstract
In mammals, behavioral activity is regulated both by the circadian system, orchestrated by the suprachiasmatic nucleus (SCN), and by arousal structures, including the serotonergic system. While the SCN is active at the same astronomical time in diurnal and nocturnal species, little data are available concerning the serotonergic (5HT) system in diurnal mammals. In this study, we investigated the functioning of the 5HT system, which is involved both in regulating the sleep/wake cycle and in synchronizing the SCN, in a diurnal rodent, Arvicanthis ansorgei. Using in situ hybridization, we characterized the anatomical extension of the raphe nuclei and we investigated 24 h mRNA levels of the serotonin rate-limiting enzyme, tryptophan hydroxylase 2 (tph2). Under both 12 h:12 h light/dark (LD) and constant darkness (DD) conditions, tph2 mRNA expression varies significantly over 24 h, displaying a bimodal profile with higher values around the (projected) light transitions. Furthermore, we considered several SCN outputs, namely melatonin, corticosterone, and locomotor activity. In both LD and DD, melatonin profiles display peak levels during the biological night. Corticosterone plasma levels show a bimodal rhythmic profile in both conditions, with higher levels preceding the two peaks of Arvicanthis locomotor activity, occurring at dawn and dusk. These data demonstrate that serotonin synthesis in Arvicanthis is rhythmic and reflects its bimodal behavioral phenotype, but differs from what has been previously described in nocturnal species.
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Affiliation(s)
- Rosanna Caputo
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France.,Department of Molecular Cell Biology, Division of Neurophysiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Vincent-Joseph Poirel
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
| | - Etienne Challet
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
| | - Johanna H Meijer
- Department of Molecular Cell Biology, Division of Neurophysiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Sylvie Raison
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
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6
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Gray ALH, Sawaya MR, Acharyya D, Lou J, Edington EM, Best MD, Prosser RA, Eisenberg DS, Do TD. Atomic view of an amyloid dodecamer exhibiting selective cellular toxic vulnerability in acute brain slices. Protein Sci 2022; 31:716-727. [PMID: 34954854 PMCID: PMC8862425 DOI: 10.1002/pro.4268] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 12/14/2021] [Accepted: 12/23/2021] [Indexed: 12/16/2022]
Abstract
Atomic structures of amyloid oligomers that capture the neurodegenerative disease pathology are essential to understand disease-state causes and finding cures. Here we investigate the G6W mutation of the cytotoxic, hexameric amyloid model KV11. The mutation results into an asymmetric dodecamer composed of a pair of 30° twisted antiparallel β-sheets. The complete break between adjacent β-strands is unprecedented among amyloid fibril crystal structures and supports that our structure is an oligomer. The poor shape complementarity between mated sheets reveals an interior channel for binding lipids, suggesting that the toxicity may be due to a perturbation of lipid transport rather than a direct disruption of membrane integrity. Viability assays on mouse suprachiasmatic nucleus, anterior hypothalamus, and cerebral cortex demonstrated selective regional vulnerability consistent with Alzheimer's disease. Neuropeptides released from the brain slices may provide clues to how G6W initiates cellular injury.
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Affiliation(s)
- Amber L. H. Gray
- Department of ChemistryUniversity of TennesseeKnoxvilleTennesseeUSA
| | - Michael R. Sawaya
- HHMIUniversity of CaliforniaLos AngelesCaliforniaUSA,Department of Chemistry and BiochemistryUniversity of CaliforniaLos AngelesCaliforniaUSA,Department of Biological ChemistryUniversity of CaliforniaLos AngelesCaliforniaUSA,Molecular Biology InstituteUniversity of CaliforniaLos AngelesCaliforniaUSA,Department of Energy Institute for Genomics and ProteomicsUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - Debalina Acharyya
- Department of Biochemistry & Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleTennesseeUSA
| | - Jinchao Lou
- Department of ChemistryUniversity of TennesseeKnoxvilleTennesseeUSA
| | | | - Michael D. Best
- Department of ChemistryUniversity of TennesseeKnoxvilleTennesseeUSA
| | - Rebecca A. Prosser
- Department of Biochemistry & Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleTennesseeUSA
| | - David S. Eisenberg
- HHMIUniversity of CaliforniaLos AngelesCaliforniaUSA,Department of Chemistry and BiochemistryUniversity of CaliforniaLos AngelesCaliforniaUSA,Department of Biological ChemistryUniversity of CaliforniaLos AngelesCaliforniaUSA,Molecular Biology InstituteUniversity of CaliforniaLos AngelesCaliforniaUSA,Department of Energy Institute for Genomics and ProteomicsUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - Thanh D. Do
- Department of ChemistryUniversity of TennesseeKnoxvilleTennesseeUSA
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7
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Kawakami S, Yoshitane H, Morimura T, Kimura W, Fukada Y. Diurnal shift of mouse activity by the deficiency of an aging-related gene Lmna. J Biochem 2022; 171:509-518. [PMID: 35137145 DOI: 10.1093/jb/mvac015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 02/02/2022] [Indexed: 11/13/2022] Open
Abstract
Nuclear lamina is a fundamental structure of the cell nucleus and regulates a wide range of molecular pathways. Defects of components of the nuclear lamina cause aging-like physiological disorders, called laminopathy. Generally, aging and diseases are often associated with perturbation of various time-of-day-dependent regulations, but it remains still elusive whether laminopathy induces any changes of the circadian clock and physiological rhythms. Here we demonstrated that deficiency of Lmna gene in mice caused an obvious shift of locomotor activities to the daytime. The abnormal activity profile was accompanied by a remarkable change in phase-angle between the central clock in the suprachiasmatic nucleus (SCN) and lung peripheral clocks, leaving the phase of the SCN clock unaffected by the mutation. These observations suggest that Lmna deficiency causes a change of the habitat from nocturnal to diurnal behaviors. On the other hand, molecular oscillation and its phase resetting mechanism were intact in both the Lmna-deficient cells and progeria-mimicking cells. Intriguingly, high-fat diet feeding extended the short lifespan and ameliorated the abnormalities of the behaviors and the phase of the peripheral clock in the Lmna-deficient mice. The present study supports the important contribution of the energy conditions to a shift between the diurnal and nocturnal activities.
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Affiliation(s)
- Satoshi Kawakami
- Department of Biological Sciences, School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.,Circadian Clock Project, Tokyo Metropolitan Institute of Medical Science, Kamikitazawa 2-1-6, Setagaya-ku, Tokyo 156-8506, Japan
| | - Hikari Yoshitane
- Department of Biological Sciences, School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.,Circadian Clock Project, Tokyo Metropolitan Institute of Medical Science, Kamikitazawa 2-1-6, Setagaya-ku, Tokyo 156-8506, Japan
| | - Taiki Morimura
- Department of Biological Sciences, School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.,Circadian Clock Project, Tokyo Metropolitan Institute of Medical Science, Kamikitazawa 2-1-6, Setagaya-ku, Tokyo 156-8506, Japan
| | - Wataru Kimura
- RIKEN Center for Biosystems Dynamics Research, Minatojima-minamimachi 2-2-3, Chuo-ku, Kobe, Hyogo 650-0043, Japan
| | - Yoshitaka Fukada
- Department of Biological Sciences, School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.,Circadian Clock Project, Tokyo Metropolitan Institute of Medical Science, Kamikitazawa 2-1-6, Setagaya-ku, Tokyo 156-8506, Japan.,Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
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8
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Kumar D, Sharma A, Taliyan R, Urmera MT, Herrera-Calderon O, Heinbockel T, Rahman S, Goyal R. Orchestration of the circadian clock and its association with Alzheimer's disease: Role of endocannabinoid signaling. Ageing Res Rev 2022; 73:101533. [PMID: 34844016 PMCID: PMC8729113 DOI: 10.1016/j.arr.2021.101533] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 10/24/2021] [Accepted: 11/22/2021] [Indexed: 01/03/2023]
Abstract
Circadian rhythms are 24-hour natural rhythms regulated by the suprachiasmatic nucleus, also known as the "master clock". The retino-hypothalamic tract entrains suprachiasmatic nucleus with photic information to synchronise endogenous circadian rhythms with the Earth's light-dark cycle. However, despite the robustness of circadian rhythms, an unhealthy lifestyle and chronic photic disturbances cause circadian rhythm disruption in the suprachiasmatic nucleus's TTFL loops via affecting glutamate and γ-aminobutyric acid-mediated neurotransmission in the suprachiasmatic nucleus. Recently, considerable evidence has been shown correlating CRd with the incidence of Alzheimer's disease. The present review aims to identify the existence and signalling of endocannabinoids in CRd induced Alzheimer's disease through retino-hypothalamic tract- suprachiasmatic nucleus-cortex. Immunohistochemistry has confirmed the expression of cannabinoid receptor 1 in the suprachiasmatic nucleus to modulate the circadian phases of the master clock. Literature also suggests that cannabinoids may alter activity of suprachiasmatic nucleus by influencing the activity of their major neurotransmitter γ-aminobutyric acid or by interacting indirectly with the suprachiasmatic nucleus's two other major inputs i.e., the geniculo-hypothalamic tract-mediated release of neuropeptide Y and serotonergic inputs from the dorsal raphe nuclei. Besides, the expression of cannabinoid receptor 2 ameliorates cognitive deficits via reduction of tauopathy and microglial activation. In conclusion, endocannabinoids may be identified as a putative target for correcting CRd and decelerating Alzheimer's disease.
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Affiliation(s)
- Deepak Kumar
- Department of Neuropharmacology, School of Pharmaceutical Sciences, Shoolini University of Biotechnology and Management Sciences, Solan, H.P. 173229, India.
| | - Ashish Sharma
- School of Medicine, Washington University, St. Louis, USA.
| | - Rajeev Taliyan
- Neuropharmacology Laboratory, Department of Pharmacy, Birla Institute of Technology Science, Pilani, Rajasthan 333301, India.
| | - Maiko T Urmera
- Institute on Aging and Centre for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Oscar Herrera-Calderon
- Department of Pharmacology, Bromatology and Toxicology, Faculty of Pharmacy and Biochemistry, Universidad Nacional Mayor de San Marcos, Lima, Peru.
| | - Thomas Heinbockel
- Howard University College of Medicine, District of Columbia, WA, USA.
| | - Shafiqur Rahman
- Department of Pharmaceutical Sciences, College of Pharmacy South Dakota State University, Brookings, SD, USA.
| | - Rohit Goyal
- Department of Neuropharmacology, School of Pharmaceutical Sciences, Shoolini University of Biotechnology and Management Sciences, Solan, H.P. 173229, India.
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9
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Kumar D, Sharma A, Taliyan R, Urmera MT, Herrera-Calderon O, Heinbockel T, Rahman S, Goyal R. Orchestration of the circadian clock and its association with Alzheimer's disease: Role of endocannabinoid signaling. Ageing Res Rev 2022. [DOI: https://doi.org/10.1016/j.arr.2021.101533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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10
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Li Y, Androulakis IP. Light-induced synchronization of the SCN coupled oscillators and implications for entraining the HPA axis. Front Endocrinol (Lausanne) 2022; 13:960351. [PMID: 36387856 PMCID: PMC9648564 DOI: 10.3389/fendo.2022.960351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) synchronizes the physiological rhythms to the external light-dark cycle and tunes the dynamics of circadian rhythms to photoperiod fluctuations. Changes in the neuronal network topologies are suggested to cause adaptation of the SCN in different photoperiods, resulting in the broader phase distribution of neuron activities in long photoperiods (LP) compared to short photoperiods (SP). Regulated by the SCN output, the level of glucocorticoids is elevated in short photoperiod, which is associated with peak disease incidence. The underlying coupling mechanisms of the SCN and the interplay between the SCN and the HPA axis have yet to be fully elucidated. In this work, we propose a mathematical model including a multiple-cellular SCN compartment and the HPA axis to investigate the properties of the circadian timing system under photoperiod changes. Our model predicts that the probability-dependent network is more energy-efficient than the distance-dependent network. Coupling the SCN network by intra-subpopulation and inter-subpopulation forces, we identified the negative correlation between robustness and plasticity of the oscillatory network. The HPA rhythms were predicted to be strongly entrained to the SCN rhythms with a pro-inflammatory high-amplitude glucocorticoid profile under SP. The fast temporal topology switch of the SCN network was predicted to enhance synchronization when the synchronization is not complete. These synchronization and circadian dynamics alterations might govern the seasonal variation of disease incidence and its symptom severity.
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Affiliation(s)
- Yannuo Li
- Chemical & Biochemical Engineering Department, Rutgers University, Piscataway, NJ, United States
| | - Ioannis P. Androulakis
- Chemical & Biochemical Engineering Department, Rutgers University, Piscataway, NJ, United States
- Biomedical Engineering Department, Rutgers University, Piscataway, NJ, United States
- *Correspondence: Ioannis P. Androulakis,
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11
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Li Y, Androulakis IP. Light entrainment of the SCN circadian clock and implications for personalized alterations of corticosterone rhythms in shift work and jet lag. Sci Rep 2021; 11:17929. [PMID: 34504149 PMCID: PMC8429702 DOI: 10.1038/s41598-021-97019-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/21/2021] [Indexed: 11/17/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) functions as the central pacemaker aligning physiological and behavioral oscillations to day/night (activity/inactivity) transitions. The light signal entrains the molecular clock of the photo-sensitive ventrolateral (VL) core of the SCN which in turn entrains the dorsomedial (DM) shell via the neurotransmitter vasoactive intestinal polypeptide (VIP). The shell converts the VIP rhythmic signals to circadian oscillations of arginine vasopressin (AVP), which eventually act as a neurotransmitter signal entraining the hypothalamic–pituitary–adrenal (HPA) axis, leading to robust circadian secretion of glucocorticoids. In this work, we discuss a semi-mechanistic mathematical model that reflects the essential hierarchical structure of the photic signal transduction from the SCN to the HPA axis. By incorporating the interactions across the core, the shell, and the HPA axis, we investigate how these coupled systems synchronize leading to robust circadian oscillations. Our model predicts the existence of personalized synchronization strategies that enable the maintenance of homeostatic rhythms while allowing for differential responses to transient and permanent light schedule changes. We simulated different behavioral situations leading to perturbed rhythmicity, performed a detailed computational analysis of the dynamic response of the system under varying light schedules, and determined that (1) significant interindividual diversity and flexibility characterize adaptation to varying light schedules; (2) an individual’s tolerances to jet lag and alternating shift work are positively correlated, while the tolerances to jet lag and transient shift work are negatively correlated, which indicates trade-offs in an individual’s ability to maintain physiological rhythmicity; (3) weak light sensitivity leads to the reduction of circadian flexibility, implying that light therapy can be a potential approach to address shift work and jet lag related disorders. Finally, we developed a map of the impact of the synchronization within the SCN and between the SCN and the HPA axis as it relates to the emergence of circadian flexibility.
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Affiliation(s)
- Yannuo Li
- Chemical & Biochemical Engineering Department, Rutgers, Piscataway, USA
| | - Ioannis P Androulakis
- Chemical & Biochemical Engineering Department, Rutgers, Piscataway, USA. .,Biomedical Engineering Department, Rutgers, Piscataway, USA. .,Departmnet of Surgery, Rutgers-RWJMS, Piscataway, USA.
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12
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Coomans C, Saaltink DJ, Deboer T, Tersteeg M, Lanooij S, Schneider AF, Mulder A, van Minnen J, Jost C, Koster AJ, Vreugdenhil E. Doublecortin-like expressing astrocytes of the suprachiasmatic nucleus are implicated in the biosynthesis of vasopressin and influences circadian rhythms. Glia 2021; 69:2752-2766. [PMID: 34343377 PMCID: PMC9291169 DOI: 10.1002/glia.24069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 11/09/2022]
Abstract
We have recently identified a novel plasticity protein, doublecortin-like (DCL), that is specifically expressed in the shell of the mouse suprachiasmatic nucleus (SCN). DCL is implicated in neuroplastic events, such as neurogenesis, that require structural rearrangements of the microtubule cytoskeleton, enabling dynamic movements of cell bodies and dendrites. We have inspected DCL expression in the SCN by confocal microscopy and found that DCL is expressed in GABA transporter-3 (GAT3)-positive astrocytes that envelope arginine vasopressin (AVP)-expressing cells. To investigate the role of these DCL-positive astrocytes in circadian rhythmicity, we have used transgenic mice expressing doxycycline-induced short-hairpin (sh) RNA's targeting DCL mRNA (DCL knockdown mice). Compared with littermate wild type (WT) controls, DCL-knockdown mice exhibit significant shorter circadian rest-activity periods in constant darkness and adjusted significantly faster to a jet-lag protocol. As DCL-positive astrocytes are closely associated with AVP-positive cells, we analyzed AVP expression in DCL-knockdown mice and in their WT littermates by 3D reconstructions and transmission electron microscopy (TEM). We found significantly higher numbers of AVP-positive cells with increased volume and more intensity in DCL-knockdown mice. We found alterations in the numbers of dense core vesicle-containing neurons at ZT8 and ZT20 suggesting that the peak and trough of neuropeptide biosynthesis is dampened in DCL-knockdown mice compared to WT littermates. Together, our data suggest an important role for the astrocytic plasticity in the regulation of circadian rhythms and point to the existence of a specific DCL+ astrocyte-AVP+ neuronal network located in the dorsal SCN implicated in AVP biosynthesis.
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Affiliation(s)
- Claudia Coomans
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Dirk-Jan Saaltink
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Tom Deboer
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mayke Tersteeg
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Suzanne Lanooij
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Anne Fleur Schneider
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Aat Mulder
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jan van Minnen
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Carolina Jost
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Abraham J Koster
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Erno Vreugdenhil
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
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13
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Abstract
Female reproductive success relies on proper integration of circadian- and ovarian- signals to the hypothalamic-pituitary-gonadal axis in order to synchronize the preovulatory LH surge at the end of the ovarian follicular stage with the onset of the main active period. In this study, we used a combination of neuroanatomical and electrophysiological approaches to assess whether the hypothalamic neurons expressing Arg-Phe amide-related peptide (RFRP-3), a gonadotropin inhibitory peptide, exhibit daily and estrous stage dependent variations in female mice. Furthermore, we investigated whether arginine vasopressin (AVP), a circadian peptide produced by the suprachiamatic nucleus regulates RFRP-3 neurons. The number of c-Fos–positive RFRP-3 immunoreactive neurons is significantly reduced at the day-to-night transition with no difference between diestrus and proestrus. Contrastingly, RFRP neuron firing rate is higher in proestrus as compared to diestrus, independently of the time of the day. AVP immunoreactive fibers contact RFRP neurons with the highest density observed during the late afternoon of diestrus and proestrus. Application of AVP increases RFRP neurons firing in the afternoon (ZT6-10) of diestrus, but not at the same time point of proestrus, indicating that AVP signaling on RFRP neurons may depend on circulating ovarian steroids. Together, these studies show that RFRP neurons integrate both daily and estrogenic signals, which downstream may help to properly time the preovulatory LH surge.
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Abstract
Many molecular, physiological and behavioural processes display distinct 24-hour rhythms that are directed by the circadian system. The master clock, located in the suprachiasmatic nucleus region of the hypothalamus, is synchronized or entrained by the light-dark cycle and, in turn, synchronizes clocks present in peripheral tissues and organs. Other environmental cues, most importantly feeding time, also synchronize peripheral clocks. In this way, the circadian system can prepare the body for predictable environmental changes such as the availability of nutrients during the normal feeding period. This Review summarizes existing knowledge about the diurnal regulation of gastrointestinal processes by circadian clocks present in the digestive tract and its accessory organs. The circadian control of gastrointestinal digestion, motility, hormones and barrier function as well as of the gut microbiota are discussed. An overview is given of the interplay between different circadian clocks in the digestive system that regulate glucose homeostasis and lipid and bile acid metabolism. Additionally, the bidirectional interaction between the master clock and peripheral clocks in the digestive system, encompassing different entraining factors, is described. Finally, the possible behavioural adjustments or pharmacological strategies for the prevention and treatment of the adverse effects of chronodisruption are outlined.
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15
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Cheng AH, Cheng HYM. Genesis of the Master Circadian Pacemaker in Mice. Front Neurosci 2021; 15:659974. [PMID: 33833665 PMCID: PMC8021851 DOI: 10.3389/fnins.2021.659974] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/04/2021] [Indexed: 12/13/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) of the hypothalamus is the central circadian clock of mammals. It is responsible for communicating temporal information to peripheral oscillators via humoral and endocrine signaling, ultimately controlling overt rhythms such as sleep-wake cycles, body temperature, and locomotor activity. Given the heterogeneity and complexity of the SCN, its genesis is tightly regulated by countless intrinsic and extrinsic factors. Here, we provide a brief overview of the development of the SCN, with special emphasis on the murine system.
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Affiliation(s)
- Arthur H. Cheng
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Hai-Ying Mary Cheng
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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16
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Kalsbeek A, Buijs RM. Organization of the neuroendocrine and autonomic hypothalamic paraventricular nucleus. HANDBOOK OF CLINICAL NEUROLOGY 2021; 180:45-63. [PMID: 34225948 DOI: 10.1016/b978-0-12-820107-7.00004-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A major function of the nervous system is to maintain a relatively constant internal environment. The distinction between our external environment (i.e., the environment that we live in and that is subject to major changes, such as temperature, humidity, and food availability) and our internal environment (i.e., the environment formed by the fluids surrounding our bodily tissues and that has a very stable composition) was pointed out in 1878 by Claude Bernard (1814-1878). Later on, it was indicated by Walter Cannon (1871-1945) that the internal environment is not really constant, but rather shows limited variability. Cannon named the mechanism maintaining this limited variability homeostasis. Claude Bernard envisioned that, for optimal health, all physiologic processes in the body needed to maintain homeostasis and should be in perfect harmony with each other. This is illustrated by the fact that, for instance, during the sleep-wake cycle important elements of our physiology such as body temperature, circulating glucose, and cortisol levels show important variations but are in perfect synchrony with each other. These variations are driven by the biologic clock in interaction with hypothalamic target areas, among which is the paraventricular nucleus of the hypothalamus (PVN), a core brain structure that controls the neuroendocrine and autonomic nervous systems and thus is key for integrating central and peripheral information and implementing homeostasis. This chapter focuses on the anatomic connections between the biologic clock and the PVN to modulate homeostasis according to the daily sleep-wake rhythm. Experimental studies have revealed a highly specialized organization of the connections between the clock neurons and neuroendocrine system as well as preautonomic neurons in the PVN. These complex connections ensure a logical coordination between behavioral, endocrine, and metabolic functions that helps the organism maintain homeostasis throughout the day.
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Affiliation(s)
- Andries Kalsbeek
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers (Amsterdam UMC), University of Amsterdam, Amsterdam, The Netherlands; Department of Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands.
| | - Ruud M Buijs
- Hypothalamic Integration Mechanisms Laboratory, Department of Cellular Biology and Physiology, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
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17
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Joye DAM, Rohr KE, Keller D, Inda T, Telega A, Pancholi H, Carmona-Alcocer V, Evans JA. Reduced VIP Expression Affects Circadian Clock Function in VIP-IRES-CRE Mice (JAX 010908). J Biol Rhythms 2020; 35:340-352. [PMID: 32460660 DOI: 10.1177/0748730420925573] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Circadian rhythms are programmed by the suprachiasmatic nucleus (SCN), which relies on neuropeptide signaling to maintain daily timekeeping. Vasoactive intestinal polypeptide (VIP) is critical for SCN function, but the precise role of VIP neurons in SCN circuits is not fully established. To interrogate their contribution to SCN circuits, VIP neurons can be manipulated specifically using the DNA-editing enzyme Cre recombinase. Although the Cre transgene is assumed to be inert by itself, we find that VIP expression is reduced in both heterozygous and homozygous adult VIP-IRES-Cre mice (JAX 010908). Compared with wild-type mice, homozygous VIP-Cre mice display faster reentrainment and shorter free-running period but do not become arrhythmic in constant darkness. Consistent with this phenotype, homozygous VIP-Cre mice display intact SCN PER2::LUC rhythms, albeit with altered period and network organization. We present evidence that the ability to sustain molecular rhythms in the VIP-Cre SCN is not due to residual VIP signaling; rather, arginine vasopressin signaling helps to sustain SCN function at both intracellular and intercellular levels in this model. This work establishes that the VIP-IRES-Cre transgene interferes with VIP expression but that loss of VIP can be mitigated by other neuropeptide signals to help sustain SCN function. Our findings have implications for studies employing this transgenic model and provide novel insight into neuropeptide signals that sustain daily timekeeping in the master clock.
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Affiliation(s)
- Deborah A M Joye
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Kayla E Rohr
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Danielle Keller
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Thomas Inda
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Adam Telega
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Harshida Pancholi
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | | | - Jennifer A Evans
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
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18
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Hozer C, Pifferi F, Aujard F, Perret M. The Biological Clock in Gray Mouse Lemur: Adaptive, Evolutionary and Aging Considerations in an Emerging Non-human Primate Model. Front Physiol 2019; 10:1033. [PMID: 31447706 PMCID: PMC6696974 DOI: 10.3389/fphys.2019.01033] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/26/2019] [Indexed: 01/04/2023] Open
Abstract
Circadian rhythms, which measure time on a scale of 24 h, are genetically generated by the circadian clock, which plays a crucial role in the regulation of almost every physiological and metabolic process in most organisms. This review gathers all the available information about the circadian clock in a small Malagasy primate, the gray mouse lemur (Microcebus murinus), and reports 30 years data from the historical colony at Brunoy (France). Although the mouse lemur has long been seen as a "primitive" species, its clock displays high phenotypic plasticity, allowing perfect adaptation of its biological rhythms to environmental challenges (seasonality, food availability). The alterations of the circadian timing system in M. murinus during aging show many similarities with those in human aging. Comparisons are drawn with other mammalian species (more specifically, with rodents, other non-human primates and humans) to demonstrate that the gray mouse lemur is a good complementary and alternative model for studying the circadian clock and, more broadly, brain aging and pathologies.
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Hannibal J, Norn THB, Georg B, Fahrenkrug J. Spatiotemporal expression pattern of PERIOD 1 and PERIOD 2 in the mouse SCN is dependent on VIP receptor 2 signaling. Eur J Neurosci 2019; 50:3115-3132. [PMID: 31211910 DOI: 10.1111/ejn.14482] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 04/29/2019] [Accepted: 05/21/2019] [Indexed: 11/29/2022]
Abstract
Neurons of the hypothalamic suprachiasmatic nucleus (SCN) express clock genes, which regulate their own transcription and generate daily output signals driving circadian rhythmic behavior and physiology. The neuropeptide VIP and its specific receptor, the VPAC2 receptor, are important for synchronization of clock neurons. In the present study, we characterized PER1 and PER2 expressing neurons in wild-type and VPAC2-deficient mice. We found evidence for distinct spatiotemporal circadian oscillation in the expression of the PER genes in two separate clusters of SCN neurons. In wild-type mice corresponding to the SCN shell and ventral core, high expression of PER was found at lights-off most likely representing an evening clock (E-clock). In another smaller cluster of neurons located in the central core of the SCN, PER expression peaks in antiphase at lights-on and could represent a morning clock (M-clock). BMAL1 immunoreactivity was found to be expressed in antiphase to PER in M and E neurons, respectively. PER was found in 98% of neurons expressing vasopressin (AVP) and in 92% of VIP neurons. The chemotype of M neurons was not identified. M but not E cells were responsive to long but not short photoperiods. The expression of the VPAC2 receptor was found in both M and E cells, and VPAC2-deficient mice displayed markedly blunted PER expression in both cell clusters of the SCN. Conclusion: These observations support the existence of M and E clocks involved in circadian and seasonal adaptation, which seem dependent on intact VIP/VPAC2 signaling in the SCN.
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Affiliation(s)
- Jens Hannibal
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Tania H B Norn
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte Georg
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jan Fahrenkrug
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
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20
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Lin MS, Liao PY, Chen HM, Chang CP, Chen SK, Chern Y. Degeneration of ipRGCs in Mouse Models of Huntington's Disease Disrupts Non-Image-Forming Behaviors Before Motor Impairment. J Neurosci 2019; 39:1505-1524. [PMID: 30587542 PMCID: PMC6381252 DOI: 10.1523/jneurosci.0571-18.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 11/22/2018] [Accepted: 12/17/2018] [Indexed: 12/20/2022] Open
Abstract
Intrinsically photosensitive retinal ganglion cells (ipRGCs), which express the photopigment melanopsin, are photosensitive neurons in the retina and are essential for non-image-forming functions, circadian photoentrainment, and pupillary light reflexes. Five subtypes of ipRGCs (M1-M5) have been identified in mice. Although ipRGCs are spared in several forms of inherited blindness, they are affected in Alzheimer's disease and aging, which are associated with impaired circadian rhythms. Huntington's disease (HD) is an autosomal neurodegenerative disease caused by the expansion of a CAG repeat in the huntingtin gene. In addition to motor function impairment, HD mice also show impaired circadian rhythms and loss of ipRGC. Here, we found that, in HD mouse models (R6/2 and N171-82Q male mice), the expression of melanopsin was reduced before the onset of motor deficits. The expression of retinal T-box brain 2, a transcription factor essential for ipRGCs, was associated with the survival of ipRGCs. The number of M1 ipRGCs in R6/2 male mice was reduced due to apoptosis, whereas non-M1 ipRGCs were relatively resilient to HD progression. Most importantly, the reduced innervations of M1 ipRGCs, which was assessed by X-gal staining in R6/2-OPN4Lacz/+ male mice, contributed to the diminished light-induced c-fos and vasoactive intestinal peptide in the suprachiasmatic nuclei (SCN), which may explain the impaired circadian photoentrainment in HD mice. Collectively, our results show that M1 ipRGCs were susceptible to the toxicity caused by mutant Huntingtin. The resultant impairment of M1 ipRGCs contributed to the early degeneration of the ipRGC-SCN pathway and disrupted circadian regulation during HD progression.SIGNIFICANCE STATEMENT Circadian disruption is a common nonmotor symptom of Huntington's disease (HD). In addition to the molecular defects in the suprachiasmatic nuclei (SCN), the cause of circadian disruption in HD remains to be further explored. We hypothesized that ipRGCs, by integrating light input to the SCN, participate in the circadian regulation in HD mice. We report early reductions in melanopsin in two mouse models of HD, R6/2, and N171-82Q. Suppression of retinal T-box brain 2, a transcription factor essential for ipRGCs, by mutant Huntingtin might mediate the reduced number of ipRGCs. Importantly, M1 ipRGCs showed higher susceptibility than non-M1 ipRGCs in R6/2 mice. The resultant impairment of M1 ipRGCs contributed to the early degeneration of the ipRGC-SCN pathway and the circadian abnormality during HD progression.
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Affiliation(s)
- Meng-Syuan Lin
- Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei 115, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, and
| | - Po-Yu Liao
- Department of Life Science, National Taiwan University, Taipei 106, Taiwan
| | - Hui-Mei Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, and
| | - Ching-Pang Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, and
| | - Shih-Kuo Chen
- Department of Life Science, National Taiwan University, Taipei 106, Taiwan
| | - Yijuang Chern
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, and
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21
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Hannou L, Roy P, Ballester Roig MN, Mongrain V. Transcriptional control of synaptic components by the clock machinery. Eur J Neurosci 2019; 51:241-267. [DOI: 10.1111/ejn.14294] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/01/2018] [Accepted: 11/27/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Lydia Hannou
- Center for Advanced Research in Sleep Medicine and Research CenterHôpital du Sacré‐Cœur de Montréal (CIUSSS‐NIM) Montreal Quebec Canada
- Department of PsychiatryUniversité de Montréal Montreal Quebec Canada
| | - Pierre‐Gabriel Roy
- Center for Advanced Research in Sleep Medicine and Research CenterHôpital du Sacré‐Cœur de Montréal (CIUSSS‐NIM) Montreal Quebec Canada
- Department of NeuroscienceUniversité de Montréal Montreal Quebec Canada
| | - Maria Neus Ballester Roig
- Center for Advanced Research in Sleep Medicine and Research CenterHôpital du Sacré‐Cœur de Montréal (CIUSSS‐NIM) Montreal Quebec Canada
- Department of NeuroscienceUniversité de Montréal Montreal Quebec Canada
| | - Valérie Mongrain
- Center for Advanced Research in Sleep Medicine and Research CenterHôpital du Sacré‐Cœur de Montréal (CIUSSS‐NIM) Montreal Quebec Canada
- Department of NeuroscienceUniversité de Montréal Montreal Quebec Canada
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22
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de Goede P, Sen S, Su Y, Foppen E, Poirel VJ, Challet E, Kalsbeek A. An Ultradian Feeding Schedule in Rats Affects Metabolic Gene Expression in Liver, Brown Adipose Tissue and Skeletal Muscle with Only Mild Effects on Circadian Clocks. Int J Mol Sci 2018; 19:E3171. [PMID: 30326619 PMCID: PMC6214081 DOI: 10.3390/ijms19103171] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/04/2018] [Accepted: 10/11/2018] [Indexed: 12/21/2022] Open
Abstract
Restricted feeding is well known to affect expression profiles of both clock and metabolic genes. However, it is unknown whether these changes in metabolic gene expression result from changes in the molecular clock or in feeding behavior. Here we eliminated the daily rhythm in feeding behavior by providing 6 meals evenly distributed over the light/dark-cycle. Animals on this 6-meals-a-day feeding schedule retained the normal day/night difference in physiological parameters including body temperature and locomotor activity. The daily rhythm in respiratory exchange ratio (RER), however, was significantly phase-shifted through increased utilization of carbohydrates during the light phase and increased lipid oxidation during the dark phase. This 6-meals-a-day feeding schedule did not have a major impact on the clock gene expression rhythms in the master clock, but did have mild effects on peripheral clocks. In contrast, genes involved in glucose and lipid metabolism showed differential expression. In conclusion, eliminating the daily rhythm in feeding behavior in rats does not affect the master clock and only mildly affects peripheral clocks, but disturbs metabolic rhythms in liver, skeletal muscle and brown adipose tissue in a tissue-dependent manner. Thereby, a clear daily rhythm in feeding behavior strongly regulates timing of peripheral metabolism, separately from circadian clocks.
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Affiliation(s)
- Paul de Goede
- Laboratory of Endocrinology, Department of Clinical Chemistry, Amsterdam UMC, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands.
| | - Satish Sen
- Laboratory of Endocrinology, Department of Clinical Chemistry, Amsterdam UMC, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands.
- Hypothalamic Integration Mechanisms Group, Netherlands Institute for Neuroscience (NIN), Amsterdam 1105 BA, The Netherlands.
- Circadian Clocks & Metabolism Team, Institute of Cellular and Integrative Neurosciences, UPR3212, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, Strasbourg 67000, France.
| | - Yan Su
- Laboratory of Endocrinology, Department of Clinical Chemistry, Amsterdam UMC, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands.
- Hypothalamic Integration Mechanisms Group, Netherlands Institute for Neuroscience (NIN), Amsterdam 1105 BA, The Netherlands.
| | - Ewout Foppen
- Laboratory of Endocrinology, Department of Clinical Chemistry, Amsterdam UMC, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands.
- Hypothalamic Integration Mechanisms Group, Netherlands Institute for Neuroscience (NIN), Amsterdam 1105 BA, The Netherlands.
| | - Vincent-Joseph Poirel
- Melatonin and Seasonal Rhythms Team, Institute of Cellular and Integrative Neurosciences, UPR3212, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, Strasbourg 67000, France.
| | - Etienne Challet
- Circadian Clocks & Metabolism Team, Institute of Cellular and Integrative Neurosciences, UPR3212, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, Strasbourg 67000, France.
| | - Andries Kalsbeek
- Laboratory of Endocrinology, Department of Clinical Chemistry, Amsterdam UMC, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands.
- Hypothalamic Integration Mechanisms Group, Netherlands Institute for Neuroscience (NIN), Amsterdam 1105 BA, The Netherlands.
- Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands.
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Santoso P, Nakata M, Ueta Y, Yada T. Suprachiasmatic vasopressin to paraventricular oxytocin neurocircuit in the hypothalamus relays light reception to inhibit feeding behavior. Am J Physiol Endocrinol Metab 2018; 315:E478-E488. [PMID: 28174180 DOI: 10.1152/ajpendo.00338.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Light synchronizes the body's circadian rhythms by modulating the master clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus. In modern lifestyles that run counter to normal circadian rhythms, the extended and/or irregular light exposure impairs circadian rhythms and, consequently, promotes feeding and metabolic disorders. However, the neuronal pathway through which light is coupled to feeding behavior is less elucidated. The present study employed the light exposure during the dark phase of the day in rats and observed its effect on neuronal activity and feeding behavior. Light exposure acutely suppressed food intake and elevated c-Fos expression in the AVP neurons of SCN and the oxytocin (Oxt) neurons of paraventricular nucleus (PVN) in the hypothalamus. The light-induced suppression of food intake was abolished by blockade of the Oxt receptor in the brain. Retrograde tracer analysis demonstrated the projection of SCN AVP neurons to the PVN. Furthermore, intracerebroventricular injection of AVP suppressed food intake and increased c-Fos in PVN Oxt neurons. Intra-PVN injection of AVP exerted a stronger anorexigenic effect than intracerebroventriclar injection. AVP also induced intracellular Ca2+ signaling and increased firing frequency in Oxt neurons in PVN slices. These results reveal the novel neurocircuit from SCN AVP to PVN Oxt that relays light reception to inhibition of feeding behavior. This light-induced neurocircuit may serve as a pathway for forming the circadian feeding rhythm and linking irregular light exposure to arrhythmic feeding and, consequently, obesity and metabolic diseases.
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Affiliation(s)
- Putra Santoso
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi , Japan
| | - Masanori Nakata
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi , Japan
| | - Yoichi Ueta
- Department of Physiology, University of Occupational and Environmental Health , Kitakyushu , Japan
| | - Toshihiko Yada
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi , Japan
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24
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Atkins N, Ren S, Hatcher N, Burgoon PW, Mitchell JW, Sweedler JV, Gillette MU. Functional Peptidomics: Stimulus- and Time-of-Day-Specific Peptide Release in the Mammalian Circadian Clock. ACS Chem Neurosci 2018; 9:2001-2008. [PMID: 29901982 DOI: 10.1021/acschemneuro.8b00089] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Daily oscillations of brain and body states are under complex temporal modulation by environmental light and the hypothalamic suprachiasmatic nucleus (SCN), the master circadian clock. To better understand mediators of differential temporal modulation, we characterize neuropeptide releasate profiles by nonselective capture of secreted neuropeptides in an optic nerve horizontal SCN brain slice model. Releasates are collected following electrophysiological stimulation of the optic nerve/retinohypothalamic tract under conditions that alter the phase of the SCN activity state. Secreted neuropeptides are identified by intact mass via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We found time-of-day-specific suites of peptides released downstream of optic nerve stimulation. Peptide release was modified differentially with respect to time-of-day by stimulus parameters and by inhibitors of glutamatergic or PACAPergic neurotransmission. The results suggest that SCN physiology is modulated by differential peptide release of both known and unexpected peptides that communicate time-of-day-specific photic signals via previously unreported neuropeptide signatures.
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Abstract
The kidneys regulate many vital functions that require precise control throughout the day. These functions, such as maintaining sodium balance or regulating arterial pressure, rely on an intrinsic clock mechanism that was commonly believed to be controlled by the central nervous system. Mounting evidence in recent years has unveiled previously underappreciated depth of influence by circadian rhythms and clock genes on renal function, at the molecular and physiological level, independent of other external factors. The impact of circadian rhythms in the kidney also affects individuals from a clinical standpoint, as the loss of rhythmic activity or clock gene expression have been documented in various cardiovascular diseases. Fortunately, the prognostic value of examining circadian rhythms may prove useful in determining the progression of a kidney-related disease, and chronotherapy is a clinical intervention that requires consideration of circadian and diurnal rhythms in the kidney. In this review, we discuss evidence of circadian regulation in the kidney from basic and clinical research in order to provide a foundation on which a great deal of future research is needed to expand our understanding of circadian relevant biology.
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Affiliation(s)
- Jermaine G Johnston
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - David M Pollock
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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26
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Central Circadian Clock Regulates Energy Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1090:79-103. [PMID: 30390286 DOI: 10.1007/978-981-13-1286-1_5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Our body not only responds to environmental changes but also anticipates them. The light and dark cycle with the period of about 24 h is a recurring environmental change that determines the diurnal variation in food availability and safety from predators in nature. As a result, the circadian clock is evolved in most animals to align locomotor behaviors and energy metabolism with the light cue. The central circadian clock in mammals is located at the suprachiasmatic nucleus (SCN) of the hypothalamus in the brain. We here review the molecular and anatomic architecture of the central circadian clock in mammals, describe the experimental and observational evidence that suggests a critical role of the central circadian clock in shaping systemic energy metabolism, and discuss the involvement of endocrine factors, neuropeptides, and the autonomic nervous system in the metabolic functions of the central circadian clock.
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27
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Mishra I, Singh D, Kumar V. Temporal Expression of c-fos and Genes Coding for Neuropeptides and Enzymes of Amino Acid and Amine Neurotransmitter Biosynthesis in Retina, Pineal and Hypothalamus of a Migratory Songbird: Evidence for Circadian Rhythm-Dependent Seasonal Responses. Neuroscience 2017; 371:309-324. [PMID: 29273324 DOI: 10.1016/j.neuroscience.2017.12.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 12/10/2017] [Accepted: 12/12/2017] [Indexed: 10/18/2022]
Abstract
This study investigated whether, in photoperiodic songbirds, the circadian pacemaker system (CPS) connects to the seasonal photoperiodic responses, by changes at transcriptional level in the level and 24-h rhythm of its constituent neurotransmitters. We used black-headed buntings (Emberiza melanocephala), which exhibit distinct seasonal states in captivity under appropriate photoperiods and hence served as a useful model system. Under short days, buntings remain in the photosensitive state (Pse) (winter phenotype: non-migratory, non-breeding). Under long days, however, buntings undergo through early-photostimulated (spring phenotype: pre-migratory, pre-breeding), late photostimulated (summer phenotype: migratory, breeding) and photorefractory (autumn phenotype: post-breeding) states. During all four seasonal states, we measured in the retina, pineal and hypothalamus, which together form avian CPS, 4-hourly mRNA expression of c-fos (a neuronal-activity marker) and of genes coding for neuropeptides (vasoactive intestinal peptide, vip; somatostatin, sst; neuropeptide Y, npy) and for intermediary enzymes of amino acid (glutamate: glutaminase, gls and glutamic-oxaloacetic transaminase 2, got2; GABA: glutamic acid decarboxylase, gad65) and amine (dopamine: tyrosine hydroxylase, th) neurotransmitters biosynthetic pathway. There was a significant alteration in level and 24-h pattern of mRNA expression, albeit with seasonal differences in presence, waveform parameters and phase relationship of 24-h rhythm, of different genes. Particularly, mRNA expression of all candidate genes (except hypothalamic vip, pineal gls and retinal th) was arrhythmic in late photostimulated state. These results underscore that circadian rhythm of peptide, amino acid and amine neurotransmitter biosynthesis in CPS plays a critical role in the photoperiodic regulation of seasonal states in birds.
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Affiliation(s)
- Ila Mishra
- IndoUS Center for Biological Timing, Department of Zoology, University of Delhi, Delhi 110 007, India
| | - Devraj Singh
- IndoUS Center for Biological Timing, Department of Zoology, University of Delhi, Delhi 110 007, India
| | - Vinod Kumar
- IndoUS Center for Biological Timing, Department of Zoology, University of Delhi, Delhi 110 007, India.
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Lai B, Zou J, Lin Z, Qu Z, Song A, Xu Y, Gao X. Haploinsufficiency of hnRNP U Changes Activity Pattern and Metabolic Rhythms. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 188:173-183. [PMID: 29128567 DOI: 10.1016/j.ajpath.2017.09.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/26/2017] [Accepted: 09/21/2017] [Indexed: 12/25/2022]
Abstract
The neuropeptides arginine vasopressin (Avp) and vasoactive intestinal polypeptide (Vip) are critical for the communication and coupling of suprachiasmatic nucleus neurons, which organize daily rhythms of physiology and behavior in mammals. However, how these peptides are regulated remains uncharacterized. We found that heterogeneous nuclear ribonucleoprotein U (hnRNP U) is essential for the expression of Avp and Vip. Loss of one copy of the Hnrnpu gene resulted in fragmented locomotor activities and disrupted metabolic rhythms. Hnrnpu+/- mice were more active than wild-type mice in the daytime but more inactive at night. These phenotypes were partially rescued by microinfusion of Avp and Vip into free-moving animals. In addition, hnRNP U modulated Avp and Vip via directly binding to their promoters together with brain and muscle Arnt-like protein-1/circadian locomotor output cycles kaput heterodimers. Our work identifies hnRNP U as a novel regulator of the circadian pacemaker and provides new insights into the mechanism of rhythm output.
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Affiliation(s)
- Beibei Lai
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Collaborative Innovation Center of Genetics and Development, Nanjing University, Nanjing, China
| | - Jianghuan Zou
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Collaborative Innovation Center of Genetics and Development, Nanjing University, Nanjing, China
| | - Zhaoyu Lin
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Collaborative Innovation Center of Genetics and Development, Nanjing University, Nanjing, China
| | - Zhipeng Qu
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Collaborative Innovation Center of Genetics and Development, Nanjing University, Nanjing, China
| | - Anying Song
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Collaborative Innovation Center of Genetics and Development, Nanjing University, Nanjing, China
| | - Ying Xu
- Medical College of Soochou University, Suzhou, China.
| | - Xiang Gao
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Collaborative Innovation Center of Genetics and Development, Nanjing University, Nanjing, China.
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Cruz BP, Brongar LF, Popiolek P, Gonçalvez BSB, Figueiredo MA, Amaral IPG, Da Rosa VS, Nery LEM, Marins LF. Clock genes expression and locomotor activity are altered along the light-dark cycle in transgenic zebrafish overexpressing growth hormone. Transgenic Res 2017; 26:739-752. [PMID: 28795260 DOI: 10.1007/s11248-017-0039-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 08/02/2017] [Indexed: 12/16/2022]
Abstract
In the present work it was demonstrated that transgenic Danio rerio overexpressing growth hormone (GH-transgenic) present either altered gene expression at a determined time point, or different expression pattern along the LD cycle, when compared with non-transgenic (NT) animals, in the positive and negative loops of the circadian system. Gene expression of clock paralogs was reduced in GH fish at the beginning of the dark phase, leading to diminished expression amplitude along the LD cycle. Furthermore, although no differences were observed between NT and GH animals for bmal1a and cry2b expression at each time point, only GH fish presented amplitude along the LD cycle. Also, the locomotor activity behavior was evaluated for both groups. GH-transgenic animals presented higher locomotor activity along the whole LD cycle when compared with NT animals. These data suggest that alterations in the gene expression patterns along the LD cycle of the positive and negative loops of the circadian system, could lead to altered locomotor activity behavior in GH-transgenic fish, and GH overexpression could be responsible for these alterations, either affecting the pathways involved in the expression of genes from the circadian system or altering the metabolism.
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Affiliation(s)
- B P Cruz
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande (FURG), Av. Itália, Km 8, Rio Grande, RS, 96201-900, Brazil
| | - L F Brongar
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande (FURG), Av. Itália, Km 8, Rio Grande, RS, 96201-900, Brazil
| | - P Popiolek
- Centro de Ciências Computacionais (C3), Universidade Federal do Rio Grande (FURG), Rio Grande, Brazil
| | - B S B Gonçalvez
- Instituto Federal Sudeste de Minas Gerais, Campus Barbacena, Barbacena, Brazil
| | - M A Figueiredo
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande (FURG), Av. Itália, Km 8, Rio Grande, RS, 96201-900, Brazil
| | - I P G Amaral
- Centro de Biotecnologia, Universidade Federal da Paraíba, Campus I, João Pessoa, Brazil
| | - V S Da Rosa
- Centro de Ciências Computacionais (C3), Universidade Federal do Rio Grande (FURG), Rio Grande, Brazil
| | - L E M Nery
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande (FURG), Av. Itália, Km 8, Rio Grande, RS, 96201-900, Brazil.
| | - L F Marins
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande (FURG), Av. Itália, Km 8, Rio Grande, RS, 96201-900, Brazil
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Oster H, Challet E, Ott V, Arvat E, de Kloet ER, Dijk DJ, Lightman S, Vgontzas A, Van Cauter E. The Functional and Clinical Significance of the 24-Hour Rhythm of Circulating Glucocorticoids. Endocr Rev 2017; 38:3-45. [PMID: 27749086 PMCID: PMC5563520 DOI: 10.1210/er.2015-1080] [Citation(s) in RCA: 294] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 09/21/2016] [Indexed: 02/07/2023]
Abstract
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 long been recognized that this 24-hour rhythm partly reflects the activity of a master circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus. In the past decade, secondary circadian clocks based on the same molecular machinery as the central master pacemaker were found in other brain areas as well as in most peripheral tissues, including the adrenal glands. Evidence is rapidly accumulating to indicate that misalignment between central and peripheral clocks has a host of adverse effects. The robust rhythm in circulating glucocorticoid levels has been recognized as a major internal synchronizer of the circadian system. The present review examines the scientific foundation of these novel advances and their implications for health and disease prevention and treatment.
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Affiliation(s)
- Henrik Oster
- Medical Department I (H.O., V.O.), University of Lübeck, 23562 Lübeck, Germany; Institute for Cellular and Integrative Neuroscience (E.C.), Centre National de la Recherche Scientifique (CNRS) UPR 3212, University of Strasbourg, 67084 Strasbourg, France; Division of Endocrinology, Diabetology and Metabolism (E.A.), Department of Internal Medicine, University of Turin, 10043 Turin, Italy; Department of Endocrinology and Metabolic Disease (E.R.d.K.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; Surrey Sleep Research Center (D.-J.D.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (S.L.), University of Bristol, Bristol BS8 1TH, United Kingdom; Sleep Research and Treatment Center (A.V.), Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033; and Sleep, Metabolism, and Health Center (E.V.C.), Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Etienne Challet
- Medical Department I (H.O., V.O.), University of Lübeck, 23562 Lübeck, Germany; Institute for Cellular and Integrative Neuroscience (E.C.), Centre National de la Recherche Scientifique (CNRS) UPR 3212, University of Strasbourg, 67084 Strasbourg, France; Division of Endocrinology, Diabetology and Metabolism (E.A.), Department of Internal Medicine, University of Turin, 10043 Turin, Italy; Department of Endocrinology and Metabolic Disease (E.R.d.K.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; Surrey Sleep Research Center (D.-J.D.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (S.L.), University of Bristol, Bristol BS8 1TH, United Kingdom; Sleep Research and Treatment Center (A.V.), Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033; and Sleep, Metabolism, and Health Center (E.V.C.), Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Volker Ott
- Medical Department I (H.O., V.O.), University of Lübeck, 23562 Lübeck, Germany; Institute for Cellular and Integrative Neuroscience (E.C.), Centre National de la Recherche Scientifique (CNRS) UPR 3212, University of Strasbourg, 67084 Strasbourg, France; Division of Endocrinology, Diabetology and Metabolism (E.A.), Department of Internal Medicine, University of Turin, 10043 Turin, Italy; Department of Endocrinology and Metabolic Disease (E.R.d.K.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; Surrey Sleep Research Center (D.-J.D.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (S.L.), University of Bristol, Bristol BS8 1TH, United Kingdom; Sleep Research and Treatment Center (A.V.), Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033; and Sleep, Metabolism, and Health Center (E.V.C.), Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Emanuela Arvat
- Medical Department I (H.O., V.O.), University of Lübeck, 23562 Lübeck, Germany; Institute for Cellular and Integrative Neuroscience (E.C.), Centre National de la Recherche Scientifique (CNRS) UPR 3212, University of Strasbourg, 67084 Strasbourg, France; Division of Endocrinology, Diabetology and Metabolism (E.A.), Department of Internal Medicine, University of Turin, 10043 Turin, Italy; Department of Endocrinology and Metabolic Disease (E.R.d.K.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; Surrey Sleep Research Center (D.-J.D.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (S.L.), University of Bristol, Bristol BS8 1TH, United Kingdom; Sleep Research and Treatment Center (A.V.), Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033; and Sleep, Metabolism, and Health Center (E.V.C.), Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - E Ronald de Kloet
- Medical Department I (H.O., V.O.), University of Lübeck, 23562 Lübeck, Germany; Institute for Cellular and Integrative Neuroscience (E.C.), Centre National de la Recherche Scientifique (CNRS) UPR 3212, University of Strasbourg, 67084 Strasbourg, France; Division of Endocrinology, Diabetology and Metabolism (E.A.), Department of Internal Medicine, University of Turin, 10043 Turin, Italy; Department of Endocrinology and Metabolic Disease (E.R.d.K.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; Surrey Sleep Research Center (D.-J.D.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (S.L.), University of Bristol, Bristol BS8 1TH, United Kingdom; Sleep Research and Treatment Center (A.V.), Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033; and Sleep, Metabolism, and Health Center (E.V.C.), Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Derk-Jan Dijk
- Medical Department I (H.O., V.O.), University of Lübeck, 23562 Lübeck, Germany; Institute for Cellular and Integrative Neuroscience (E.C.), Centre National de la Recherche Scientifique (CNRS) UPR 3212, University of Strasbourg, 67084 Strasbourg, France; Division of Endocrinology, Diabetology and Metabolism (E.A.), Department of Internal Medicine, University of Turin, 10043 Turin, Italy; Department of Endocrinology and Metabolic Disease (E.R.d.K.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; Surrey Sleep Research Center (D.-J.D.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (S.L.), University of Bristol, Bristol BS8 1TH, United Kingdom; Sleep Research and Treatment Center (A.V.), Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033; and Sleep, Metabolism, and Health Center (E.V.C.), Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Stafford Lightman
- Medical Department I (H.O., V.O.), University of Lübeck, 23562 Lübeck, Germany; Institute for Cellular and Integrative Neuroscience (E.C.), Centre National de la Recherche Scientifique (CNRS) UPR 3212, University of Strasbourg, 67084 Strasbourg, France; Division of Endocrinology, Diabetology and Metabolism (E.A.), Department of Internal Medicine, University of Turin, 10043 Turin, Italy; Department of Endocrinology and Metabolic Disease (E.R.d.K.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; Surrey Sleep Research Center (D.-J.D.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (S.L.), University of Bristol, Bristol BS8 1TH, United Kingdom; Sleep Research and Treatment Center (A.V.), Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033; and Sleep, Metabolism, and Health Center (E.V.C.), Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Alexandros Vgontzas
- Medical Department I (H.O., V.O.), University of Lübeck, 23562 Lübeck, Germany; Institute for Cellular and Integrative Neuroscience (E.C.), Centre National de la Recherche Scientifique (CNRS) UPR 3212, University of Strasbourg, 67084 Strasbourg, France; Division of Endocrinology, Diabetology and Metabolism (E.A.), Department of Internal Medicine, University of Turin, 10043 Turin, Italy; Department of Endocrinology and Metabolic Disease (E.R.d.K.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; Surrey Sleep Research Center (D.-J.D.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (S.L.), University of Bristol, Bristol BS8 1TH, United Kingdom; Sleep Research and Treatment Center (A.V.), Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033; and Sleep, Metabolism, and Health Center (E.V.C.), Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Eve Van Cauter
- Medical Department I (H.O., V.O.), University of Lübeck, 23562 Lübeck, Germany; Institute for Cellular and Integrative Neuroscience (E.C.), Centre National de la Recherche Scientifique (CNRS) UPR 3212, University of Strasbourg, 67084 Strasbourg, France; Division of Endocrinology, Diabetology and Metabolism (E.A.), Department of Internal Medicine, University of Turin, 10043 Turin, Italy; Department of Endocrinology and Metabolic Disease (E.R.d.K.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; Surrey Sleep Research Center (D.-J.D.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XP, United Kingdom; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (S.L.), University of Bristol, Bristol BS8 1TH, United Kingdom; Sleep Research and Treatment Center (A.V.), Department of Psychiatry, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033; and Sleep, Metabolism, and Health Center (E.V.C.), Department of Medicine, University of Chicago, Chicago, Illinois 60637
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Dardente H, Wyse CA, Lincoln GA, Wagner GC, Hazlerigg DG. Effects of Photoperiod Extension on Clock Gene and Neuropeptide RNA Expression in the SCN of the Soay Sheep. PLoS One 2016; 11:e0159201. [PMID: 27458725 PMCID: PMC4961288 DOI: 10.1371/journal.pone.0159201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/28/2016] [Indexed: 01/23/2023] Open
Abstract
In mammals, changing daylength (photoperiod) is the main synchronizer of seasonal functions. The photoperiodic information is transmitted through the retino-hypothalamic tract to the suprachiasmatic nuclei (SCN), site of the master circadian clock. To investigate effects of day length change on the sheep SCN, we used in-situ hybridization to assess the daily temporal organization of expression of circadian clock genes (Per1, Per2, Bmal1 and Fbxl21) and neuropeptides (Vip, Grp and Avp) in animals acclimated to a short photoperiod (SP; 8h of light) and at 3 or 15 days following transfer to a long photoperiod (LP3, LP15, respectively; 16h of light), achieved by an acute 8-h delay of lights off. We found that waveforms of SCN gene expression conformed to those previously seen in LP acclimated animals within 3 days of transfer to LP. Mean levels of expression for Per1-2 and Fbxl21 were nearly 2-fold higher in the LP15 than in the SP group. The expression of Vip was arrhythmic and unaffected by photoperiod, while, in contrast to rodents, Grp expression was not detectable within the sheep SCN. Expression of the circadian output gene Avp cycled robustly in all photoperiod groups with no detectable change in phasing. Overall these data suggest that synchronizing effects of light on SCN circadian organisation proceed similarly in ungulates and in rodents, despite differences in neuropeptide gene expression.
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Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- * E-mail: (DGH); (HD)
| | - Cathy A. Wyse
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- Veterinary school, Bearsden Road, Glasgow, G61 1QH, United Kingdom
| | - Gerald A. Lincoln
- Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4SB, United Kingdom
| | - Gabriela C. Wagner
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- Department of Arctic and Marine Biology, Faculty of BioSciences, Fisheries and Economy, University of Tromsø, 9037, Tromsø, Norway
| | - David G. Hazlerigg
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- Department of Arctic and Marine Biology, Faculty of BioSciences, Fisheries and Economy, University of Tromsø, 9037, Tromsø, Norway
- * E-mail: (DGH); (HD)
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Evans JA. Collective timekeeping among cells of the master circadian clock. J Endocrinol 2016; 230:R27-49. [PMID: 27154335 PMCID: PMC4938744 DOI: 10.1530/joe-16-0054] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/06/2016] [Indexed: 01/09/2023]
Abstract
The suprachiasmatic nucleus (SCN) of the anterior hypothalamus is the master circadian clock that coordinates daily rhythms in behavior and physiology in mammals. Like other hypothalamic nuclei, the SCN displays an impressive array of distinct cell types characterized by differences in neurotransmitter and neuropeptide expression. Individual SCN neurons and glia are able to display self-sustained circadian rhythms in cellular function that are regulated at the molecular level by a 24h transcriptional-translational feedback loop. Remarkably, SCN cells are able to harmonize with one another to sustain coherent rhythms at the tissue level. Mechanisms of cellular communication in the SCN network are not completely understood, but recent progress has provided insight into the functional roles of several SCN signaling factors. This review discusses SCN organization, how intercellular communication is critical for maintaining network function, and the signaling mechanisms that play a role in this process. Despite recent progress, our understanding of SCN circuitry and coupling is far from complete. Further work is needed to map SCN circuitry fully and define the signaling mechanisms that allow for collective timekeeping in the SCN network.
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Affiliation(s)
- Jennifer A Evans
- Department of Biomedical SciencesMarquette University, Milwaukee, WI, USA
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Lambert CM, Machida KK, Smale L, Nunez AA, Weaver DR. Analysis of the Prokineticin 2 System in a Diurnal Rodent, the Unstriped Nile Grass Rat (Arvicanthis niloticus). J Biol Rhythms 2016; 20:206-18. [PMID: 15851527 DOI: 10.1177/0748730405275135] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Prokineticin 2 (PK2) is a putative output molecule from the SCN. PK2 RNA levels are rhythmic in the mouse SCN, with high levels during the day, and PK2 administration suppresses nocturnal locomotor activity in rats. The authors examined the PK2 system in a diurnal rodent, Arvicanthis niloticus, to determine whether PK2 or PK2 receptors differ between diurnal and nocturnal species. The major transcript variant of A. niloticus PK2 ( AnPK2) encodes a 26-residue signal peptide followed by the presumed mature peptide of 81 residues. Within the grass rat signal sequence, polymorphic sequences and amino acid substitutions were observed relative to mouse and laboratory rats, but the hydrophobic core and cleavage site of the signal sequence were preserved. The mature PK2 peptide is identical among A. niloticus, rat, and mouse. AnPK2 mRNA is rhythmically expressed in the SCN, with peak RNAlevels occurring in the morning, preceding peaks of Per1 and Per2 as in mouse SCN. Analysis of prokineticin receptor 2 (PKR2) sequences revealed polymorphisms among the grass rats studied. PKR2 mRNAwas expressed in the SCN and paraventricular nuclei of the thalamus and hypothalamus. While further analysis is necessary, there is no clear evidence indicating that a difference in the PK2 ligand/receptor system accounts for diurnality in this rodent species. These data contribute to a growing body of evidence suggesting that the key to diurnality lies downstream of the SCN in A. niloticus.
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Affiliation(s)
- Christopher M Lambert
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605-2324, USA
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Yap CC, Wharfe MD, Mark PJ, Waddell BJ, Smith JT. Diurnal regulation of hypothalamic kisspeptin is disrupted during mouse pregnancy. J Endocrinol 2016; 229:307-18. [PMID: 27068699 DOI: 10.1530/joe-16-0086] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 04/11/2016] [Indexed: 12/20/2022]
Abstract
Kisspeptin, the neuropeptide product of the Kiss1 gene, is critical in driving the hypothalamic-pituitary-gonadal (HPG) axis. Kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (Arc) of the hypothalamus mediate differential effects, with the Arc regulating negative feedback of sex steroids and the AVPV regulating positive feedback, vital for the preovulatory surge and gated under circadian control. We aimed to characterize hypothalamic Kiss1 and Kiss1r mRNA expression in nonpregnant and pregnant mice, and investigate potential circadian regulation. Anterior and posterior hypothalami were collected from C57BL/6J mice at diestrus, proestrus, and days 6, 10, 14, and 18 of pregnancy, at six time points across 24h, for real-time PCR analysis of gene expression. Analysis confirmed that Kiss1 mRNA expression in the AVPV increased at ZT13 during proestrus, with a luteinizing hormone surge observed thereafter. No diurnal regulation was seen at diestrus or at any stage of pregnancy. Anterior hypothalamic Avp mRNA expression exhibited no diurnal variation, but Avpr1a peaked at 12:00h during proestrus, possibly reflecting the circadian input from the suprachiasmatic nucleus to AVPV Kiss1 neurons. Rfrp (Npvf) expression in the posterior hypothalamus did not demonstrate diurnal variation at any stage. Clock genes Bmal1 and Rev-erbα were strongly diurnal, but there was little change between diestrus/proestrus and pregnancy. Our data indicate the absence of the circadian input to Kiss1 in pregnancy, despite high gestational estradiol levels and normal clock gene expression, and may suggest a disruption of a kisspeptin-specific diurnal rhythm that operates in the nonpregnant state.
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Affiliation(s)
- Cassandra C Yap
- School of AnatomyPhysiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
| | - Michaela D Wharfe
- School of AnatomyPhysiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
| | - Peter J Mark
- School of AnatomyPhysiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
| | - Brendan J Waddell
- School of AnatomyPhysiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
| | - Jeremy T Smith
- School of AnatomyPhysiology and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
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Jha PK, Foppen E, Kalsbeek A, Challet E. Sleep restriction acutely impairs glucose tolerance in rats. Physiol Rep 2016; 4:e12839. [PMID: 27354542 PMCID: PMC4923238 DOI: 10.14814/phy2.12839] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 05/23/2016] [Accepted: 05/31/2016] [Indexed: 11/24/2022] Open
Abstract
Chronic sleep curtailment in humans has been related to impairment of glucose metabolism. To better understand the underlying mechanisms, the purpose of the present study was to investigate the effect of acute sleep deprivation on glucose tolerance in rats. A group of rats was challenged by 4-h sleep deprivation in the early rest period, leading to prolonged (16 h) wakefulness. Another group of rats was allowed to sleep during the first 4 h of the light period and sleep deprived in the next 4 h. During treatment, food was withdrawn to avoid a postmeal rise in plasma glucose. An intravenous glucose tolerance test (IVGTT) was performed immediately after the sleep deprivation period. Sleep deprivation at both times of the day similarly impaired glucose tolerance and reduced the early-phase insulin responses to a glucose challenge. Basal concentrations of plasma glucose, insulin, and corticosterone remained unchanged after sleep deprivation. Throughout IVGTTs, plasma corticosterone concentrations were not different between the control and sleep-deprived group. Together, these results demonstrate that independent of time of day and sleep pressure, short sleep deprivation during the resting phase favors glucose intolerance in rats by attenuating the first-phase insulin response to a glucose load. In conclusion, this study highlights the acute adverse effects of only a short sleep restriction on glucose homeostasis.
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Affiliation(s)
- Pawan K Jha
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, the Netherlands Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands Regulation of Circadian Clocks team, Institute of Cellular and Integrative Neurosciences UPR3212 Centre National de la Recherche Scientifique (CNRS) University of Strasbourg, Strasbourg, France International Associated Laboratory LIA1061 Understanding the Neural Basis of Diurnality, CNRS, France and the Netherlands
| | - Ewout Foppen
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, the Netherlands
| | - Andries Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, the Netherlands Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands International Associated Laboratory LIA1061 Understanding the Neural Basis of Diurnality, CNRS, France and the Netherlands
| | - Etienne Challet
- Regulation of Circadian Clocks team, Institute of Cellular and Integrative Neurosciences UPR3212 Centre National de la Recherche Scientifique (CNRS) University of Strasbourg, Strasbourg, France International Associated Laboratory LIA1061 Understanding the Neural Basis of Diurnality, CNRS, France and the Netherlands
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36
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Mishra I, Singh D, Kumar V. Daily expression of genes coding for neurotransmitters in central and peripheral tissues of redheaded bunting: Implication for circadian regulation of physiology in songbirds. Chronobiol Int 2016; 33:280-92. [DOI: 10.3109/07420528.2016.1139587] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Ila Mishra
- Department of Zoology, University of Delhi, Delhi, India
| | - Devraj Singh
- Department of Zoology, University of Delhi, Delhi, India
| | - Vinod Kumar
- Department of Zoology, University of Delhi, Delhi, India
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Evans JA, Gorman MR. In synch but not in step: Circadian clock circuits regulating plasticity in daily rhythms. Neuroscience 2016; 320:259-80. [PMID: 26861419 DOI: 10.1016/j.neuroscience.2016.01.072] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 01/26/2016] [Accepted: 01/27/2016] [Indexed: 11/16/2022]
Abstract
The suprachiasmatic nucleus (SCN) is a network of neural oscillators that program daily rhythms in mammalian behavior and physiology. Over the last decade much has been learned about how SCN clock neurons coordinate together in time and space to form a cohesive population. Despite this insight, much remains unknown about how SCN neurons communicate with one another to produce emergent properties of the network. Here we review the current understanding of communication among SCN clock cells and highlight a collection of formal assays where changes in SCN interactions provide for plasticity in the waveform of circadian rhythms in behavior. Future studies that pair analytical behavioral assays with modern neuroscience techniques have the potential to provide deeper insight into SCN circuit mechanisms.
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Affiliation(s)
- J A Evans
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA.
| | - M R Gorman
- Department of Psychology, University of San Diego, La Jolla, CA, USA
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38
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Achilly NP. Properties of VIP+ synapses in the suprachiasmatic nucleus highlight their role in circadian rhythm. J Neurophysiol 2015; 115:2701-4. [PMID: 26581865 DOI: 10.1152/jn.00393.2015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 11/17/2015] [Indexed: 01/19/2023] Open
Abstract
Circadian rhythms coordinate cyclical behavioral and physiological changes in most organisms. In humans, this biological clock is located within the suprachiasmatic nucleus (SCN) of the hypothalamus and consists of a heterogeneous neuron population characterized by their enriched expression of various neuropeptides. As highlighted here, Fan et al. (J Neurosci 35: 1905-1029, 2015) developed an elegant experimental system to investigate the synaptic properties of vasoactive intestinal peptide (VIP)-expressing neurons between day and night, and further delineate their broader architecture and function within the SCN.
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Affiliation(s)
- Nathan P Achilly
- Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas
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39
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Yoshikawa T, Nakajima Y, Yamada Y, Enoki R, Watanabe K, Yamazaki M, Sakimura K, Honma S, Honma KI. Spatiotemporal profiles of arginine vasopressin transcription in cultured suprachiasmatic nucleus. Eur J Neurosci 2015; 42:2678-89. [DOI: 10.1111/ejn.13061] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 08/21/2015] [Accepted: 08/27/2015] [Indexed: 01/18/2023]
Affiliation(s)
- Tomoko Yoshikawa
- Photonic Bioimaging Section; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| | - Yoshihiro Nakajima
- Health Research Institute; National Institute of Advanced Industrial Science and Technology (AIST); Kagawa 761-0395 Japan
| | - Yoshiko Yamada
- Photonic Bioimaging Section; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| | - Ryosuke Enoki
- Photonic Bioimaging Section; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Precursory Research for Embryonic Science and Technology (PRESTO); Japan Science and Technology Agency (JST); Saitama 332-0012 Japan
| | - Kazuto Watanabe
- Department of Regulatory Physiology; Dokkyo Medical University School of Medicine; Tochigi 321-0293 Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata 951-8585 Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata 951-8585 Japan
| | - Sato Honma
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| | - Ken-ichi Honma
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
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40
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Jha PK, Foppen E, Challet E, Kalsbeek A. Effects of central gastrin-releasing peptide on glucose metabolism. Brain Res 2015; 1625:135-41. [PMID: 26358150 DOI: 10.1016/j.brainres.2015.08.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 08/24/2015] [Accepted: 08/28/2015] [Indexed: 10/23/2022]
Abstract
Gastrin-releasing peptide (GRP) mediated signals in the central nervous system (CNS) influence many functions associated with energy metabolism. The purpose of the present study was to investigate the central effect of GRP on glucose metabolism in the male rat. Intracerebroventricular (icv) administration of GRP caused an immediate hyperglycaemia which was sustained till the end of the infusion. The rise in plasma glucose levels was accompanied by an increase in endogenous glucose production (EGP), as well as increases in plasma glucagon and insulin concentrations. Furthermore, no differences in plasma corticosterone levels were noted between control and GRP treated rats. These results demonstrate that central GRP increases plasma glucose levels, probably by stimulating pancreatic glucagon release and concomitantly or subsequently endogenous glucose production.
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Affiliation(s)
- Pawan Kumar Jha
- Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands; Regulation of Circadian Clocks team, Institute of Cellular and Integrative Neurosciences, UPR3212, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France; International Associated Laboratory LIA1061 Understanding the Neural Basis of Diurnality, CNRS, France and the Netherlands.
| | - Ewout Foppen
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, The Netherlands.
| | - Etienne Challet
- Regulation of Circadian Clocks team, Institute of Cellular and Integrative Neurosciences, UPR3212, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France; International Associated Laboratory LIA1061 Understanding the Neural Basis of Diurnality, CNRS, France and the Netherlands.
| | - Andries Kalsbeek
- Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands; Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, The Netherlands; International Associated Laboratory LIA1061 Understanding the Neural Basis of Diurnality, CNRS, France and the Netherlands.
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Abstract
The cellular mechanisms governing the impact of the central circadian clock on neuronal networks are incompletely understood. We examine here the influence of the suprachiasmatic nucleus output neuropeptide arginine-vasopressin (AVP) on the activity of preoptic area kisspeptin neurons. These cells integrate circadian and hormonal signals within the neuronal network that regulates fertility in females. Electrophysiological recordings in brain slices from kisspeptin-GFP mice showed that AVP dose-dependently increased the firing rate of most kisspeptin neurons. These actions were mediated directly at the kisspeptin neuron. Experiments in mice expressing the calcium indicator GCaMP3 in kisspeptin neurons enabled simultaneous monitoring of intracellular calcium concentrations ([Ca(2+)]i) in multiple cells and revealed that AVP increased [Ca(2+)]i in >80% of diestrous kisspeptin neurons via a mechanism involving voltage-gated calcium channels. We next examined whether AVP signaling in kisspeptin neurons was time and ovarian cycle dependent. AVP exerted the same effects on diestrous and proestrous days of the ovarian cycle, whether hours before [zeitgeber time 4 (ZT4)-ZT6] or just before (ZT10) the expected time of the proestrous preovulatory luteinizing hormone surge. Remarkably, however, AVP signaling was critically dependent on circulating ovarian steroids as AVP no longer excited preoptic kisspeptin neurons in ovariectomized mice, an effect that was fully restored by estradiol treatment. Together, these studies show that AVP exerts a potent and direct stimulatory influence upon the electrical activity and [Ca(2+)]i of most preoptic kisspeptin neurons. Unexpectedly, estrogen is found to permit circadian AVP signaling at preoptic kisspeptin neurons rather than dynamically modulate its activity throughout the estrous cycle.
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Bosler O, Girardet C, Franc JL, Becquet D, François-Bellan AM. Structural plasticity of the circadian timing system. An overview from flies to mammals. Front Neuroendocrinol 2015; 38:50-64. [PMID: 25703789 DOI: 10.1016/j.yfrne.2015.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 12/22/2022]
Abstract
The circadian timing system orchestrates daily variations in physiology and behavior through coordination of multioscillatory cell networks that are highly plastic in responding to environmental changes. Over the last decade, it has become clear that this plasticity involves structural changes and that the changes may be observed not only in central brain regions where the master clock cells reside but also in clock-controlled structures. This review considers experimental data in invertebrate and vertebrate model systems, mainly flies and mammals, illustrating various forms of structural circadian plasticity from cellular to circuit-based levels. It highlights the importance of these plastic events in the functional adaptation of the clock to the changing environment.
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Affiliation(s)
- Olivier Bosler
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France.
| | - Clémence Girardet
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France.
| | - Jean-Louis Franc
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France
| | - Denis Becquet
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France
| | - Anne-Marie François-Bellan
- Aix-Marseille Université, CNRS, CRN2M, UMR 7286, Faculté de médecine, secteur nord, Boulevard Pierre Dramard, CS 80011, F-13344 Marseille cedex 15, France
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43
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Ramkisoensing A, Meijer JH. Synchronization of Biological Clock Neurons by Light and Peripheral Feedback Systems Promotes Circadian Rhythms and Health. Front Neurol 2015; 6:128. [PMID: 26097465 PMCID: PMC4456861 DOI: 10.3389/fneur.2015.00128] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/19/2015] [Indexed: 12/16/2022] Open
Abstract
In mammals, the suprachiasmatic nucleus (SCN) functions as a circadian clock that drives 24-h rhythms in both physiology and behavior. The SCN is a multicellular oscillator in which individual neurons function as cell-autonomous oscillators. The production of a coherent output rhythm is dependent upon mutual synchronization among single cells and requires both synaptic communication and gap junctions. Changes in phase-synchronization between individual cells have consequences on the amplitude of the SCN’s electrical activity rhythm, and these changes play a major role in the ability to adapt to seasonal changes. Both aging and sleep deprivation negatively affect the circadian amplitude of the SCN, whereas behavioral activity (i.e., exercise) has a positive effect on amplitude. Given that the amplitude of the SCN’s electrical activity rhythm is essential for achieving robust rhythmicity in physiology and behavior, the mechanisms that underlie neuronal synchronization warrant further study. A growing body of evidence suggests that the functional integrity of the SCN contributes to health, well-being, cognitive performance, and alertness; in contrast, deterioration of the 24-h rhythm is a risk factor for neurodegenerative disease, cancer, depression, and sleep disorders.
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Affiliation(s)
- Ashna Ramkisoensing
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center , Leiden , Netherlands
| | - Johanna H Meijer
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center , Leiden , Netherlands
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44
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Hubbard J, Ruppert E, Calvel L, Robin-Choteau L, Gropp CM, Allemann C, Reibel S, Sage-Ciocca D, Bourgin P. Arvicanthis ansorgei, a Novel Model for the Study of Sleep and Waking in Diurnal Rodents. Sleep 2015; 38:979-88. [PMID: 25409107 DOI: 10.5665/sleep.4754] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 07/18/2014] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Sleep neurobiology studies use nocturnal species, mainly rats and mice. However, because their daily sleep/wake organization is inverted as compared to humans, a diurnal model for sleep studies is needed. To fill this gap, we phenotyped sleep and waking in Arvicanthis ansorgei, a diurnal rodent widely used for the study of circadian rhythms. DESIGN Video-electroencephalogram (EEG), electromyogram (EMG), and electrooculogram (EOG) recordings. SETTING Rodent sleep laboratory. PARTICIPANTS Fourteen male Arvicanthis ansorgei, aged 3 mo. INTERVENTIONS 12 h light (L):12 h dark (D) baseline condition, 24-h constant darkness, 6-h sleep deprivation. MEASUREMENTS AND RESULTS Wake and rapid eye movement (REM) sleep showed similar electrophysiological characteristics as nocturnal rodents. On average, animals spent 12.9 h ± 0.4 awake per 24-h cycle, of which 6.88 h ± 0.3 was during the light period. NREM sleep accounted for 9.63 h ± 0.4, which of 5.13 h ± 0.2 during dark period, and REM sleep for 89.9 min ± 6.7, which of 52.8 min ± 4.4 during dark period. The time-course of sleep and waking across the 12 h light:12 h dark was overall inverted to that observed in rats or mice, though with larger amounts of crepuscular activity at light and dark transitions. A dominant crepuscular regulation of sleep and waking persisted under constant darkness, showing the lack of a strong circadian drive in the absence of clock reinforcement by external cues, such as a running wheel. Conservation of the homeostatic regulation was confirmed with the observation of higher delta power following sustained waking periods and a 6-h sleep deprivation, with subsequent decrease during recovery sleep. CONCLUSIONS Arvicanthis ansorgei is a valid diurnal rodent model for studying the regulatory mechanisms of sleep and so represents a valuable tool for further understanding the nocturnality/diurnality switch.
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Affiliation(s)
- Jeffrey Hubbard
- Centre National de la Recherche Scientifique (CNRS)-UPR 3212, Institute of Cellular and Integrative Neurosciences, Strasbourg, France.,Sleep Disorders Center, Centre Hospitalier Universitaire (CHU) and Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, France
| | - Elisabeth Ruppert
- Centre National de la Recherche Scientifique (CNRS)-UPR 3212, Institute of Cellular and Integrative Neurosciences, Strasbourg, France.,Sleep Disorders Center, Centre Hospitalier Universitaire (CHU) and Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, France
| | - Laurent Calvel
- Centre National de la Recherche Scientifique (CNRS)-UPR 3212, Institute of Cellular and Integrative Neurosciences, Strasbourg, France.,Sleep Disorders Center, Centre Hospitalier Universitaire (CHU) and Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, France
| | - Ludivine Robin-Choteau
- Centre National de la Recherche Scientifique (CNRS)-UPR 3212, Institute of Cellular and Integrative Neurosciences, Strasbourg, France.,Sleep Disorders Center, Centre Hospitalier Universitaire (CHU) and Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, France
| | - Claire-Marie Gropp
- Centre National de la Recherche Scientifique (CNRS)-UPR 3212, Institute of Cellular and Integrative Neurosciences, Strasbourg, France.,Sleep Disorders Center, Centre Hospitalier Universitaire (CHU) and Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, France
| | - Caroline Allemann
- Centre National de la Recherche Scientifique (CNRS)-UPR 3212, Institute of Cellular and Integrative Neurosciences, Strasbourg, France
| | - Sophie Reibel
- Chronobiotron Centre National de la Recherche Scientifique (CNRS)-UMS 3415, Strasbourg, France
| | - Dominique Sage-Ciocca
- Chronobiotron Centre National de la Recherche Scientifique (CNRS)-UMS 3415, Strasbourg, France
| | - Patrice Bourgin
- Centre National de la Recherche Scientifique (CNRS)-UPR 3212, Institute of Cellular and Integrative Neurosciences, Strasbourg, France.,Sleep Disorders Center, Centre Hospitalier Universitaire (CHU) and Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, France
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45
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Lin LL, Huang HC, Juan HF. Circadian systems biology in Metazoa. Brief Bioinform 2015; 16:1008-24. [PMID: 25758249 DOI: 10.1093/bib/bbv006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Indexed: 12/30/2022] Open
Abstract
Systems biology, which can be defined as integrative biology, comprises multistage processes that can be used to understand components of complex biological systems of living organisms and provides hierarchical information to decoding life. Using systems biology approaches such as genomics, transcriptomics and proteomics, it is now possible to delineate more complicated interactions between circadian control systems and diseases. The circadian rhythm is a multiscale phenomenon existing within the body that influences numerous physiological activities such as changes in gene expression, protein turnover, metabolism and human behavior. In this review, we describe the relationships between the circadian control system and its related genes or proteins, and circadian rhythm disorders in systems biology studies. To maintain and modulate circadian oscillation, cells possess elaborative feedback loops composed of circadian core proteins that regulate the expression of other genes through their transcriptional activities. The disruption of these rhythms has been reported to be associated with diseases such as arrhythmia, obesity, insulin resistance, carcinogenesis and disruptions in natural oscillations in the control of cell growth. This review demonstrates that lifestyle is considered as a fundamental factor that modifies circadian rhythm, and the development of dysfunctions and diseases could be regulated by an underlying expression network with multiple circadian-associated signals.
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46
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Chronobiology and Pharmacologic Modulation of the Renin–Angiotensin–Aldosterone System in Dogs: What Have We Learned? Rev Physiol Biochem Pharmacol 2015; 169:43-69. [DOI: 10.1007/112_2015_27] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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47
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Chakir I, Dumont S, Pévet P, Ouarour A, Challet E, Vuillez P. The circadian gene Clock oscillates in the suprachiasmatic nuclei of the diurnal rodent Barbary striped grass mouse, Lemniscomys barbarus: a general feature of diurnality? Brain Res 2014; 1594:165-72. [PMID: 25449886 DOI: 10.1016/j.brainres.2014.10.063] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 10/21/2014] [Accepted: 10/28/2014] [Indexed: 10/24/2022]
Abstract
A major challenge in the field of circadian rhythms is to understand the neural mechanisms controlling the oppositely phased temporal organization of physiology and behaviour between night- and day-active animals. Most identified components of the master clock in the suprachiasmatic nuclei (SCN), called circadian genes, display similar oscillations according to the time of day, independent of the temporal niche. This has led to the predominant view that the switch between night- and day-active animals occurs downstream of the master clock, likely also involving differential feedback of behavioral cues onto the SCN. The Barbary striped grass mouse, Lemniscomys barbarus is known as a day-active Muridae. Here we show that this rodent, when housed in constant darkness, displays a temporal rhythmicity of metabolism matching its diurnal behaviour (i.e., high levels of plasma leptin and hepatic glycogen during subjective midday and dusk, respectively). Regarding clockwork in their SCN, these mice show peaks in the mRNA profiles of the circadian gene Period1 (Per1) and the clock-controlled gene Vasopressin (Avp), which occur during the middle and late subjective day, respectively, in accordance with many observations in both diurnal and nocturnal species. Strikingly, expression of the circadian gene Clock in the SCN of the Barbary striped grass mouse was not constitutive as in nocturnal rodents, but it was rhythmic. As this is also the case for the other diurnal species investigated in the literature (sheep, marmoset, and quail), a hypothesis is that the transcriptional control of Clock within the SCN participates in the mechanisms underlying diurnality and nocturnality.
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Affiliation(s)
- Ibtissam Chakir
- Faculty of Science, Laboratory of Biology and Health, Abdelmalek Essaâdi University, BP2121, Tetouan 93002, Morocco; Regulation of Circadian Clocks Team, Institute for Cellular and Integrative Neurosciences, UPR3212, CNRS and University of Strasbourg, Strasbourg, France
| | - Stéphanie Dumont
- Regulation of Circadian Clocks Team, Institute for Cellular and Integrative Neurosciences, UPR3212, CNRS and University of Strasbourg, Strasbourg, France
| | - Paul Pévet
- Regulation of Circadian Clocks Team, Institute for Cellular and Integrative Neurosciences, UPR3212, CNRS and University of Strasbourg, Strasbourg, France
| | - Ali Ouarour
- Faculty of Science, Laboratory of Biology and Health, Abdelmalek Essaâdi University, BP2121, Tetouan 93002, Morocco
| | - Etienne Challet
- Regulation of Circadian Clocks Team, Institute for Cellular and Integrative Neurosciences, UPR3212, CNRS and University of Strasbourg, Strasbourg, France
| | - Patrick Vuillez
- Regulation of Circadian Clocks Team, Institute for Cellular and Integrative Neurosciences, UPR3212, CNRS and University of Strasbourg, Strasbourg, France.
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48
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Photic stimulation of the suprachiasmatic nucleus via the non-visual optic system. A gene expression study in the blind Crx −/− mouse. Cell Tissue Res 2014; 358:239-48. [DOI: 10.1007/s00441-014-1910-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 04/23/2014] [Indexed: 12/23/2022]
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49
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Ananthasubramaniam B, Herzog ED, Herzel H. Timing of neuropeptide coupling determines synchrony and entrainment in the mammalian circadian clock. PLoS Comput Biol 2014; 10:e1003565. [PMID: 24743470 PMCID: PMC3990482 DOI: 10.1371/journal.pcbi.1003565] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 02/25/2014] [Indexed: 11/18/2022] Open
Abstract
Robust synchronization is a critical feature of several systems including the mammalian circadian clock. The master circadian clock in mammals consists of about 20000 ‘sloppy’ neuronal oscillators within the hypothalamus that keep robust time by synchronization driven by inter-neuronal coupling. The complete understanding of this synchronization in the mammalian circadian clock and the mechanisms underlying it remain an open question. Experiments and computational studies have shown that coupling individual oscillators can achieve robust synchrony, despite heterogeneity and different network topologies. But, much less is known regarding the mechanisms and circuits involved in achieving this coupling, due to both system complexity and experimental limitations. Here, we computationally study the coupling mediated by the primary coupling neuropeptide, vasoactive intestinal peptide (VIP) and its canonical receptor, VPAC2R, using the transcriptional elements and generic mode of VIP-VPAC2R signaling. We find that synchrony is only possible if VIP (an inducer of Per expression) is released in-phase with activators of Per expression. Moreover, anti-phasic VIP release suppresses coherent rhythms by moving the network into a desynchronous state. Importantly, experimentally observed rhythms in VPAC2R have little effect on network synchronization, but can improve the amplitude of the SCN network rhythms while narrowing the network entrainment range. We further show that these findings are valid across several computational network models. Thus, we identified a general design principle to achieve robust synchronization: An activating coupling agent, such as VIP, must act in-phase with the activity of core-clock promoters. More generally, the phase of coupling is as critical as the strength of coupling from the viewpoint of synchrony and entrainment. Synchronization among multiple oscillators is a common theme in many biological and engineered systems. Here, we look at its use by the mammalian biological clock to keep accurate time. Through biochemical interactions among a network of inaccurate neuron clocks, a strong precise clock is produced. Although we are gradually learning more about these biochemical interactions, the details still remain largely unclear. Studies, both computational and experimental, have shown that the strength of the rhythmic interaction critically decides if a system can synchronize, i.e., the interactions must be strong enough. In this work, we show that the rhythmic interaction between these neuronal clocks must be timed correctly (in the right phase) in addition to being strong enough to synchronize the network. Activating (repressing) interactions must coincide with other activators (repressors) in each neuron to achieve synchrony. Since this principle imposes certain properties on synchronizing interactions, these properties can be used to identify and understand novel interaction mechanisms. Further, these principles are applicable to interactions between cellular oscillators in other tissues and organisms.
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Affiliation(s)
| | - Erik D. Herzog
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Hanspeter Herzel
- Institute for Theoretical Biology, Charité and Humboldt University Berlin, Berlin, Germany
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Beltramo M, Dardente H, Cayla X, Caraty A. Cellular mechanisms and integrative timing of neuroendocrine control of GnRH secretion by kisspeptin. Mol Cell Endocrinol 2014; 382:387-399. [PMID: 24145132 DOI: 10.1016/j.mce.2013.10.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 10/08/2013] [Accepted: 10/11/2013] [Indexed: 01/11/2023]
Abstract
The hypothalamus integrates endogenous and exogenous inputs to control the pituitary-gonadal axis. The ultimate hypothalamic influence on reproductive activity is mediated through timely secretion of GnRH in the portal blood, which modulates the release of gonadotropins from the pituitary. In this context neurons expressing the RF-amide neuropeptide kisspeptin present required features to fulfill the role of the long sought-after hypothalamic integrative centre governing the stimulation of GnRH neurons. Here we focus on the intracellular signaling pathways triggered by kisspeptin through its cognate receptor KISS1R and on the potential role of proteins interacting with this receptor. We then review evidence implicating both kisspeptin and RFRP3--another RF-amide neuropeptide--in the temporal orchestration of both the pre-ovulatory LH surge in female rodents and the organization of seasonal breeding in photoperiodic species.
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Affiliation(s)
- Massimiliano Beltramo
- UMR Physiologie de la Reproduction et des Comportements (INRA, UMR85, CNRS, UMR7247, Université François Rabelais Tours, IFCE), F-37380 Nouzilly, France.
| | - Hugues Dardente
- UMR Physiologie de la Reproduction et des Comportements (INRA, UMR85, CNRS, UMR7247, Université François Rabelais Tours, IFCE), F-37380 Nouzilly, France
| | - Xavier Cayla
- UMR Physiologie de la Reproduction et des Comportements (INRA, UMR85, CNRS, UMR7247, Université François Rabelais Tours, IFCE), F-37380 Nouzilly, France
| | - Alain Caraty
- UMR Physiologie de la Reproduction et des Comportements (INRA, UMR85, CNRS, UMR7247, Université François Rabelais Tours, IFCE), F-37380 Nouzilly, France
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