1
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Salamanca G, Tagliavia C, Grandis A, Graïc JM, Cozzi B, Bombardi C. Distribution of vasoactive intestinal peptide (VIP) immunoreactivity in the rat pallial and subpallial amygdala and colocalization with γ-aminobutyric acid (GABA). Anat Rec (Hoboken) 2024; 307:2891-2911. [PMID: 38263752 DOI: 10.1002/ar.25390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 01/25/2024]
Abstract
The amygdaloid complex, also known as the amygdala, is a heterogeneous group of distinct nuclear and cortical pallial and subpallial structures. The amygdala plays an important role in several complex functions including emotional behavior and learning. The expression of calcium-binding proteins and peptides in GABAergic neurons located in the pallial and subpallial amygdala is not uniform and is sometimes restricted to specific groups of cells. Vasoactive intestinal polypeptide (VIP) is present in specific subpopulations of GABAergic cells in the amygdala. VIP immunoreactivity has been observed in somatodendritic and axonal profiles of the rat basolateral and central amygdala. However, a comprehensive analysis of the distribution of VIP immunoreactivity in the various pallial and subpallial structures is currently lacking. The present study used immunohistochemical and morphometric techniques to analyze the distribution and the neuronal localization of VIP immunoreactivity in the rat pallial and subpallial amygdala. In the pallial amygdala, VIP-IR neurons are local inhibitory interneurons that presumably directly and indirectly regulate the activity of excitatory pyramidal neurons. In the subpallial amygdala, VIP immunoreactivity is expressed in several inhibitory cell types, presumably acting as projection or local interneurons. The distribution of VIP immunoreactivity is non-homogeneous throughout the different areas of the amygdaloid complex, suggesting a distinct influence of this neuropeptide on local neuronal circuits and, consequently, on the cognitive, emotional, behavioral and endocrine activities mediated by the amygdala.
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Affiliation(s)
- G Salamanca
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - C Tagliavia
- Department of Veterinary Medicine, University of Teramo, Teramo, Italy
| | - A Grandis
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - J M Graïc
- Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Italy
| | - B Cozzi
- Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Italy
| | - C Bombardi
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
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2
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Guindon GE, Murphy CA, Milano ME, Seggio JA. Turn off that night light! Light-at-night as a stressor for adolescents. Front Neurosci 2024; 18:1451219. [PMID: 39145296 PMCID: PMC11321986 DOI: 10.3389/fnins.2024.1451219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Accepted: 07/19/2024] [Indexed: 08/16/2024] Open
Abstract
Light-at-night is known to produce a wide variety of behavioral outcomes including promoting anxiety, depression, hyperactivity, abnormal sociability, and learning and memory deficits. Unfortunately, we all live in a 24-h society where people are exposed to light-at-night or light pollution through night-shift work - the need for all-hours emergency services - as well as building and street-lights, making light-at-night exposure practically unavoidable. Additionally, the increase in screentime (tvs and smart devices) during the night also contributes to poorer sleep and behavioral impairments. Compounding these factors is the fact that adolescents tend to be "night owls" and prefer an evening chronotype compared to younger children and adults, so these teenagers will have a higher likelihood of being exposed to light-at-night. Making matters worse is the prevalence of high-school start times of 8 am or earlier - a combination of too early school start times, light exposure during the night, and preference for evening chronotypes is a recipe for reduced and poorer sleep, which can contribute to increased susceptibility for behavioral issues for this population. As such, this mini-review will show, using both human and rodent model studies, how light-at-night affects behavioral outcomes and stress responses, connecting photic signaling and the circadian timing system to the hypothalamic-pituitary adrenal axis. Additionally, this review will also demonstrate that adolescents are more likely to exhibit abnormal behavior in response to light-at-night due to changes in development and hormone regulation during this time period, as well as discuss potential interventions that can help mitigate these negative effects.
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Affiliation(s)
| | | | | | - Joseph A. Seggio
- Department of Biological Sciences, Bridgewater State University, Bridgewater, MA, United States
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3
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Gonzalez-Aponte MF, Damato AR, Simon T, Aripova N, Darby F, Rubin JB, Herzog ED. Daily glucocorticoids promote glioblastoma growth and circadian synchrony to the host. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.03.592418. [PMID: 38766060 PMCID: PMC11100585 DOI: 10.1101/2024.05.03.592418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Glioblastoma (GBM) is the most common primary brain tumor in adults with a poor prognosis despite aggressive therapy. A recent, retrospective clinical study found that administering Temozolomide in the morning increased patient overall survival by 6 months compared to evening. Here, we tested the hypothesis that daily host signaling regulates tumor growth and synchronizes circadian rhythms in GBM. We found daily Dexamethasone promoted or suppressed GBM growth depending on time of day of administration and on the clock gene, Bmal1. Blocking circadian signals, like VIP or glucocorticoids, dramatically slowed GBM growth and disease progression. Finally, mouse and human GBM models have intrinsic circadian rhythms in clock gene expression in vitro and in vivo that entrain to the host through glucocorticoid signaling, regardless of tumor type or host immune status. We conclude that GBM entrains to the circadian circuit of the brain, which modulates its growth through clockcontrolled cues, like glucocorticoids.
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Affiliation(s)
- Maria F. Gonzalez-Aponte
- Department of Biology, Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Anna R. Damato
- Department of Biology, Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Tatiana Simon
- Department of Biology, Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Nigina Aripova
- Department of Biology, Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Fabrizio Darby
- Department of Biology, Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Joshua B. Rubin
- Department of Pediatrics, St. Louis Children’s Hospital, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Erik D. Herzog
- Department of Biology, Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
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4
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Siller Wilks SJ, Heidinger BJ, Westneat DF, Solomon J, Rubenstein DR. The impact of parental and developmental stress on DNA methylation in the avian hypothalamic-pituitary-adrenal axis. Mol Ecol 2024; 33:e17291. [PMID: 38343177 DOI: 10.1111/mec.17291] [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: 09/30/2023] [Revised: 12/29/2023] [Accepted: 01/23/2024] [Indexed: 03/07/2024]
Abstract
The hypothalamic-pituitary-adrenal (HPA) axis coordinates an organism's response to environmental stress. The responsiveness and sensitivity of an offspring's stress response may be shaped not only by stressors encountered in their early post-natal environment but also by stressors in their parent's environment. Yet, few studies have considered how stressors encountered in both of these early life environments may function together to impact the developing HPA axis. Here, we manipulated stressors in the parental and post-natal environments in a population of house sparrows (Passer domesticus) to assess their impact on changes in DNA methylation (and corresponding gene expression) in a suite of genes within the HPA axis. We found that nestlings that experienced early life stress across both life-history periods had higher DNA methylation in a critical HPA axis gene, the glucocorticoid receptor (NR3C1). In addition, we found that the life-history stage when stress was encountered impacted some genes (HSD11B1, NR3C1 and NR3C2) differently. We also found evidence for the mitigation of parental stress by post-natal stress (in HSD11B1 and NR3C2). Finally, by assessing DNA methylation in both the brain and blood, we were able to evaluate cross-tissue patterns. While some differentially methylated regions were tissue-specific, we found cross-tissue changes in NR3C2 and NR3C1, suggesting that blood is a suitable tissue for assessing DNA methylation as a biomarker of early life stress. Our results provide a crucial first step in understanding the mechanisms by which early life stress in different life-history periods contributes to changes in the epigenome of the HPA axis.
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Affiliation(s)
- Stefanie J Siller Wilks
- Department of Ecology Evolution and Environmental Biology, Columbia University, New York, New York, USA
| | - Britt J Heidinger
- Biological Sciences Department, North Dakota State University, Fargo, North Dakota, USA
| | - David F Westneat
- Department of Biology, University of Kentucky, Lexington, Kentucky, USA
| | - Joseph Solomon
- Department of Ecology Evolution and Environmental Biology, Columbia University, New York, New York, USA
| | - Dustin R Rubenstein
- Department of Ecology Evolution and Environmental Biology, Columbia University, New York, New York, USA
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5
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Siller Wilks SJ, Westneat DF, Heidinger BJ, Solomon J, Rubenstein DR. Epigenetic modification of the hypothalamic-pituitary-adrenal (HPA) axis during development in the house sparrow (Passer domesticus). Gen Comp Endocrinol 2023; 341:114336. [PMID: 37328040 DOI: 10.1016/j.ygcen.2023.114336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/23/2023] [Accepted: 06/11/2023] [Indexed: 06/18/2023]
Abstract
Epigenetic modifications such as DNA methylation are important mechanisms for mediating developmental plasticity, where ontogenetic processes and their phenotypic outcomes are shaped by early environments. In particular, changes in DNA methylation of genes within the hypothalamic-pituitary-adrenal (HPA) axis can impact offspring growth and development. This relationship has been well documented in mammals but is less understood in other taxa. Here, we use target-enriched enzymatic methyl sequencing (TEEM-seq) to assess how DNA methylation in a suite of 25 genes changes over development, how these modifications relate to the early environment, and how they predict differential growth trajectories in the house sparrow (Passer domesticus). We found that DNA methylation changes dynamically over the postnatal developmental period: genes with initially low DNA methylation tended to decline in methylation over development, whereas genes with initially high DNA methylation tended to increase in methylation. However, sex-specific differentially methylated regions (DMRs) were maintained across the developmental period. We also found significant differences in post-hatching DNA methylation in relation to hatch date, with higher levels of DNA methylation in nestlings hatched earlier in the season. Although these differences were largely absent by the end of development, a number of DMRs in HPA-related genes (CRH, MC2R, NR3C1, NR3C2, POMC)-and to a lesser degree HPG-related genes (GNRHR2)-predicted nestling growth trajectories over development. These findings provide insight into the mechanisms by which the early environment shapes DNA methylation in the HPA axis, and how these changes subsequently influence growth and potentially mediate developmental plasticity.
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Affiliation(s)
- Stefanie J Siller Wilks
- Department of Ecology Evolution and Environmental Biology, Columbia University, New York, NY, USA.
| | - David F Westneat
- Department of Biology, University of Kentucky, Lexington, KY, USA
| | - Britt J Heidinger
- Biological Sciences Department, North Dakota State University, Fargo, ND, USA
| | - Joseph Solomon
- Department of Ecology Evolution and Environmental Biology, Columbia University, New York, NY, USA
| | - Dustin R Rubenstein
- Department of Ecology Evolution and Environmental Biology, Columbia University, New York, NY, USA
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6
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Moeller JS, Bever SR, Finn SL, Phumsatitpong C, Browne MF, Kriegsfeld LJ. Circadian Regulation of Hormonal Timing and the Pathophysiology of Circadian Dysregulation. Compr Physiol 2022; 12:4185-4214. [PMID: 36073751 DOI: 10.1002/cphy.c220018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Circadian rhythms are endogenously generated, daily patterns of behavior and physiology that are essential for optimal health and disease prevention. Disruptions to circadian timing are associated with a host of maladies, including metabolic disease and obesity, diabetes, heart disease, cancer, and mental health disturbances. The circadian timing system is hierarchically organized, with a master circadian clock located in the suprachiasmatic nucleus (SCN) of the anterior hypothalamus and subordinate clocks throughout the CNS and periphery. The SCN receives light information via a direct retinal pathway, synchronizing the master clock to environmental time. At the cellular level, circadian rhythms are ubiquitous, with rhythms generated by interlocking, autoregulatory transcription-translation feedback loops. At the level of the SCN, tight cellular coupling maintains rhythms even in the absence of environmental input. The SCN, in turn, communicates timing information via the autonomic nervous system and hormonal signaling. This signaling couples individual cellular oscillators at the tissue level in extra-SCN brain loci and the periphery and synchronizes subordinate clocks to external time. In the modern world, circadian disruption is widespread due to limited exposure to sunlight during the day, exposure to artificial light at night, and widespread use of light-emitting electronic devices, likely contributing to an increase in the prevalence, and the progression, of a host of disease states. The present overview focuses on the circadian control of endocrine secretions, the significance of rhythms within key endocrine axes for typical, homeostatic functioning, and implications for health and disease when dysregulated. © 2022 American Physiological Society. Compr Physiol 12: 1-30, 2022.
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Affiliation(s)
- Jacob S Moeller
- Graduate Group in Endocrinology, University of California, Berkeley, California, USA
| | - Savannah R Bever
- Department of Psychology, University of California, Berkeley, California, USA
| | - Samantha L Finn
- Department of Psychology, University of California, Berkeley, California, USA
| | | | - Madison F Browne
- Department of Psychology, University of California, Berkeley, California, USA
| | - Lance J Kriegsfeld
- Graduate Group in Endocrinology, University of California, Berkeley, California, USA.,Department of Psychology, University of California, Berkeley, California, USA.,Department of Integrative Biology, University of California, Berkeley, California, USA.,The Helen Wills Neuroscience Institute, University of California, Berkeley, California, USA
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7
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Ni R, Shu Y, Luo P, Zhou J. Sexual dimorphism in the bed nucleus of the stria terminalis, medial preoptic area and suprachiasmatic nucleus in male and female tree shrews. J Anat 2022; 240:528-540. [PMID: 34642936 PMCID: PMC8819044 DOI: 10.1111/joa.13568] [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: 06/01/2021] [Revised: 10/01/2021] [Accepted: 10/04/2021] [Indexed: 02/05/2023] Open
Abstract
Sex differences in behaviour partly arise from the sexual dimorphism of brain anatomy between males and females. However, the sexual dimorphism of the tree shrew brain is unclear. In the present study, we examined the detailed distribution of vasoactive intestinal polypeptide-immunoreactive (VIP-ir) neurons and fibres in the suprachiasmatic nucleus (SCN) and VIP-ir fibres in the bed nucleus of the stria terminalis (BST) of male and female tree shrews. The overall volume of the SCN in male tree shrews was comparable with that in females. However, males showed a significantly higher density of VIP-ir cells and fibres in the SCN than females. The shape of the VIP-stained area in coronal sections was arched, elongated or oval in the lateral division (STL) and the anterior part of the medial division (STMA) of the BST and oval or round in the posterior part of the medial division of the BST (STMP). The volume of the VIP-stained BST in male tree shrews was similar to that in females. The overall distribution of VIP-ir fibres was similar between the sexes throughout the BST except within the STMA, where darkly stained fibres were observed in males, whereas lightly stained fibres were observed in females. Furthermore, male tree shrews showed a significantly higher intensity of Nissl staining in the medial preoptic area (MPA) and the ventral part of the medial division of the BST than females. These findings are the first to reveal sexual dimorphism in the SCN, BST and MPA of the tree shrew brain, providing neuroanatomical evidence of sexual dimorphism in these regions related to their roles in sex differences in physiology and behaviour.
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Affiliation(s)
- Rong‐Jun Ni
- Psychiatric Laboratory and Mental Health CenterWest China Hospital of Sichuan UniversityChengduChina
- Huaxi Brain Research CenterWest China Hospital of Sichuan UniversityChengduChina
| | - Yu‐Mian Shu
- School of Architecture and Civil EngineeringChengdu UniversityChengduChina
| | - Peng‐Hao Luo
- Chinese Academy of Science Key Laboratory of Brain Function and DiseasesSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
| | - Jiang‐Ning Zhou
- Chinese Academy of Science Key Laboratory of Brain Function and DiseasesSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
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8
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Jones JR, Chaturvedi S, Granados-Fuentes D, Herzog ED. Circadian neurons in the paraventricular nucleus entrain and sustain daily rhythms in glucocorticoids. Nat Commun 2021; 12:5763. [PMID: 34599158 PMCID: PMC8486846 DOI: 10.1038/s41467-021-25959-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 09/02/2021] [Indexed: 02/08/2023] Open
Abstract
Signals from the central circadian pacemaker, the suprachiasmatic nucleus (SCN), must be decoded to generate daily rhythms in hormone release. Here, we hypothesized that the SCN entrains rhythms in the paraventricular nucleus (PVN) to time the daily release of corticosterone. In vivo recording revealed a critical circuit from SCN vasoactive intestinal peptide (SCNVIP)-producing neurons to PVN corticotropin-releasing hormone (PVNCRH)-producing neurons. PVNCRH neurons peak in clock gene expression around midday and in calcium activity about three hours later. Loss of the clock gene Bmal1 in CRH neurons results in arrhythmic PVNCRH calcium activity and dramatically reduces the amplitude and precision of daily corticosterone release. SCNVIP activation reduces (and inactivation increases) corticosterone release and PVNCRH calcium activity, and daily SCNVIP activation entrains PVN clock gene rhythms by inhibiting PVNCRH neurons. We conclude that daily corticosterone release depends on coordinated clock gene and neuronal activity rhythms in both SCNVIP and PVNCRH neurons.
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Affiliation(s)
- Jeff R Jones
- Department of Biology, Washington University, St. Louis, St. Louis, MO, USA
- Department of Biology, Texas A&M University, College Station, College Station, TX, USA
| | - Sneha Chaturvedi
- Department of Biology, Washington University, St. Louis, St. Louis, MO, USA
| | | | - Erik D Herzog
- Department of Biology, Washington University, St. Louis, St. Louis, MO, USA.
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9
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Szmyd B, Rogut M, Białasiewicz P, Gabryelska A. The impact of glucocorticoids and statins on sleep quality. Sleep Med Rev 2020; 55:101380. [PMID: 33010620 DOI: 10.1016/j.smrv.2020.101380] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/01/2020] [Accepted: 06/09/2020] [Indexed: 12/14/2022]
Abstract
Glucocorticoids and statins are the foundation of lifelong therapies and as such, may generate a variety of side effects. Among these, sleep impairments are one of the least explored and, simultaneously, majorly underestimated in clinical practice. Based on the available evidence, we have concluded that glucocorticoid action on the suprachiasmatic nucleus (SCN) that drives sleep disturbances is dual in nature. It involves both serotonin depletion and reduced arginine vasopressin signalling in the SCN. The former seems to involve activation of glucocorticoid receptors in the dorsal raphe, whereas the latter likely results from changes in glucose serum levels affecting the SCN, among other blood-borne factors which are yet to be discovered. Literature remains inconclusive when it comes to statins. Their diverse potential to cross the blood-brain barrier is considered the key factor determining statins' capability to evoke sleep impairments. Concurrently, an effect similar to that produced by steroids occurs - alteration in serum levels of blood-borne factors, such as glucose, which is a likely cause of statin-induced sleep disturbances.
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Affiliation(s)
- Bartosz Szmyd
- Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Poland
| | - Magdalena Rogut
- Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Poland
| | - Piotr Białasiewicz
- Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Poland
| | - Agata Gabryelska
- Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Poland.
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10
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Leach S, Suzuki K. Adrenergic Signaling in Circadian Control of Immunity. Front Immunol 2020; 11:1235. [PMID: 32714319 PMCID: PMC7344327 DOI: 10.3389/fimmu.2020.01235] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/18/2020] [Indexed: 01/07/2023] Open
Abstract
Circadian rhythms govern a multitude of physiologic processes, both on a cell-intrinsic level and systemically, through the coordinated function of multi-organ biosystems. One such system-the adrenergic system-relies on the catecholamine neurotransmitters, adrenaline and noradrenaline, to carry out a range of biological functions. Production of these catecholamines is under dual regulation by both neural components of the sympathetic nervous system and hormonal mechanisms involving the hypothalamus-pituitary-adrenal axis. Importantly, both neural and hormonal arms receive input from the body's central clock, giving rise to the observed rhythmic variations in catecholamine levels in blood and peripheral tissues. Oscillations in catecholamine signals have the potential to influence various cellular targets expressing adrenergic receptors, including cells of the immune system. This review will focus on ways in which the body's central master clock regulates the adrenergic system to generate circadian rhythms in adrenaline and noradrenaline, and will summarize the existing literature linking circadian control of the adrenergic system to immunologic outcomes. A better understanding of the complex, multi-system pathways involved in the control of adrenergic signals may provide immunologists with new insight into mechanisms of immune regulation and precipitate the discovery of new therapeutics.
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Affiliation(s)
| | - Kazuhiro Suzuki
- Laboratory of Immune Response Dynamics, Immunology Frontier Research Center, Osaka University, Osaka, Japan
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11
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Mazuski C, Chen SP, Herzog ED. Different Roles for VIP Neurons in the Neonatal and Adult Suprachiasmatic Nucleus. J Biol Rhythms 2020; 35:465-475. [PMID: 32536240 DOI: 10.1177/0748730420932073] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The suprachiasmatic nucleus (SCN) drives circadian rhythms in locomotion through coupled, single-cell oscillations. Global genetic deletion of the neuropeptide Vip or its receptor Vipr2 results in profound deficits in daily synchrony among SCN cells and daily rhythms in locomotor behavior and glucocorticoid secretion. To test whether this phenotype depends on vasoactive intestinal polypeptide (VIP) neurons in the SCN, we ablated VIP SCN neurons in vivo in adult male mice through Caspase3-mediated induction of the apoptotic pathway in cre-expressing VIP neurons. We found that ablation of VIP SCN neurons in adult mice caused a phenotype distinct from Vip- and Vipr2-null mice. Mice lacking VIP neurons retained rhythmic locomotor activity with a shortened circadian period, more variable onsets, and decreased duration of daily activity. Circadian hormonal outputs, specifically corticosterone rhythms, were severely dampened. In contrast, deletion of neonatal SCN VIP neurons dramatically reduced circadian gene expression in the cultured SCN, mimicking the effects of global deletion of Vip or Vipr2. These results suggest that SCN VIP neurons play a role in lengthening circadian period and stimulating the daily surge in glucocorticoids in adults and in synchronizing and sustaining daily rhythms among cells in the developing SCN.
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Affiliation(s)
- Cristina Mazuski
- Department of Biology, Washington University, St. Louis, Missouri
| | - Samantha P Chen
- Department of Biology, Washington University, St. Louis, Missouri
| | - Erik D Herzog
- Department of Biology, Washington University, St. Louis, Missouri
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12
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Focke CMB, Iremonger KJ. Rhythmicity matters: Circadian and ultradian patterns of HPA axis activity. Mol Cell Endocrinol 2020; 501:110652. [PMID: 31738971 DOI: 10.1016/j.mce.2019.110652] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/29/2019] [Accepted: 11/11/2019] [Indexed: 12/15/2022]
Abstract
Oscillations are a fundamental feature of neural and endocrine systems. The hypothalamic-pituitary-adrenal (HPA) axis dynamically controls corticosteroid secretion in basal conditions and in response to stress. Across the 24-h day, HPA axis activity oscillates with both an ultradian and circadian rhythm. These rhythms have been shown to be important for regulating metabolism, inflammation, mood, cognition and stress responsiveness. Here we will discuss the neural and endocrine mechanisms driving these rhythms, the physiological importance of these rhythms and health consequences when they are disrupted.
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Affiliation(s)
- Caroline M B Focke
- Centre for Neuroendocrinology, Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Karl J Iremonger
- Centre for Neuroendocrinology, Department of Physiology, University of Otago, Dunedin, New Zealand.
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13
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Korkmaz OT, Tunçel N. Advantages of Vasoactive Intestinal Peptide for the Future Treatment of Parkinson's Disease. Curr Pharm Des 2019; 24:4693-4701. [PMID: 30636594 DOI: 10.2174/1381612825666190111150953] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 01/01/2019] [Accepted: 01/02/2019] [Indexed: 01/04/2023]
Abstract
Parkinson's disease is the second most common neurodegenerative disorder in adults over the age of 65. The characteristic symptoms of Parkinson's disease, such as resting tremor, muscular rigidity, bradykinesia, postural instability and gait imbalance, are thought to be a result of the progressive degeneration of the dopaminergic neurons of the substantia nigra compacta, resulting in insufficient dopamine integrated signalling on GABAergic medium spiny neurons in the striatum. Despite tremendous research, the molecular mechanisms underlying the pathogenesis of neurodegeneration in Parkinson's disease have remained largely unknown. Although a variety of possible pathogenic mechanisms have been proposed over the years, including excessive release of oxygen free radicals, impairment of mitochondrial function, loss of trophic support, abnormal kinase activity, disruption of calcium homeostasis, dysfunction of protein degradation and neuroinflammation, the pathogenesis is still largely uncertain, and there is currently no effective cure for Parkinson's disease. To develop potential therapies for Parkinson's disease, inflammatory processes, mitochondrial dynamics, oxidative stress, production of reactive aldehydes, excitotoxicity and synucleinopathies are to be targeted. In this respect, vasoactive intestinal peptide has beneficial effects that provide an advantage for the treatment of Parkinson's disease. Vasoactive intestinal peptide is a major neuropeptide-neurotransmitter having antioxidant, anti-inflammatory, neurotropic, neuromodulator, and anti-apoptotic properties. In addition to its direct neuroprotective actions regulating the activity of astrocytes, microglia and brain mast cells, it also plays important roles for neuronal adaptation, maintenance and survival.
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Affiliation(s)
- Orhan Tansel Korkmaz
- Eskisehir Osmangazi University, Medical Faculty, Department of Physiology and Neurophysiology Eskisehir 26480, Turkey
| | - Neşe Tunçel
- Eskisehir Osmangazi University, Medical Faculty, Department of Physiology and Neurophysiology Eskisehir 26480, Turkey
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14
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Lundberg L, Sienkiewicz Z, Anthony DC, Broom KA. Effects of 50 Hz magnetic fields on circadian rhythm control in mice. Bioelectromagnetics 2019; 40:250-259. [PMID: 30945762 PMCID: PMC6617993 DOI: 10.1002/bem.22188] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 03/12/2019] [Indexed: 12/27/2022]
Abstract
Artificial light and power frequency magnetic fields are ubiquitous in the built environment. Light is a potent zeitgeber but it is unclear whether power frequency magnetic fields can influence circadian rhythm control. To study this possibility, 8-12-week-old male C57BL/6J mice were exposed for 30 min starting at zeitgeber time 14 (ZT14, 2 h into the dark period of the day) to 50 Hz magnetic fields at 580 μT using a pair of Helmholtz coils and/or a blue LED light at 700 lux or neither. Our experiments revealed an acute adrenal response to blue light, in terms of increased adrenal per1 gene expression, increased serum corticosterone levels, increased time spent sleeping, and decreased locomotor activity (in all cases, P < 0.0001) compared to an unexposed control group. There appeared to be no modulating effect of the magnetic fields on the response to light, and there was also no effect of the magnetic fields alone (in both cases, P > 0.05) except for a decrease in locomotor activity (P < 0.03). Gene expression of the cryptochromes cry1 and cry2 in the adrenals, liver, and hippocampus was also not affected by exposures (in all cases, P > 0.05). In conclusion, these results suggest that 50 Hz magnetic fields do not significantly affect the acute light response to a degree that can be detected in the adrenal response. Bioelectromagnetics. 2019;9999:XX-XX. © 2019 Bioelectromagnetics Society.
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Affiliation(s)
- Louise Lundberg
- Public Health EnglandChiltonUnited Kingdom
- Department of PharmacologyUniversity of OxfordOxfordUnited Kingdom
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15
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Duncan MJ. Interacting influences of aging and Alzheimer's disease on circadian rhythms. Eur J Neurosci 2019; 51:310-325. [DOI: 10.1111/ejn.14358] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 01/03/2019] [Accepted: 01/11/2019] [Indexed: 01/01/2023]
Affiliation(s)
- Marilyn J. Duncan
- Department of NeuroscienceUniversity of Kentucky Medical School Lexington Kentucky
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16
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REM sleep's unique associations with corticosterone regulation, apoptotic pathways, and behavior in chronic stress in mice. Proc Natl Acad Sci U S A 2019; 116:2733-2742. [PMID: 30683720 PMCID: PMC6377491 DOI: 10.1073/pnas.1816456116] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sleep disturbances are common in stress-related disorders but the nature of these sleep disturbances and how they relate to changes in the stress hormone corticosterone and changes in gene expression remained unknown. Here we demonstrate that in response to chronic mild stress, rapid–eye-movement sleep (REMS), a sleep state involved in emotion regulation and fear conditioning, changed first and more so than any other measured sleep characteristic. Transcriptomic profiles related to REMS continuity and theta oscillations overlapped with those for corticosterone, as well as with predictors for anhedonia, and were enriched for apoptotic pathways. These data highlight the central role of REMS in response to stress and warrant further investigation into REMS’s involvement in stress-related mental health disorders. One of sleep’s putative functions is mediation of adaptation to waking experiences. Chronic stress is a common waking experience; however, which specific aspect of sleep is most responsive, and how sleep changes relate to behavioral disturbances and molecular correlates remain unknown. We quantified sleep, physical, endocrine, and behavioral variables, as well as the brain and blood transcriptome in mice exposed to 9 weeks of unpredictable chronic mild stress (UCMS). Comparing 46 phenotypic variables revealed that rapid–eye-movement sleep (REMS), corticosterone regulation, and coat state were most responsive to UCMS. REMS theta oscillations were enhanced, whereas delta oscillations in non-REMS were unaffected. Transcripts affected by UCMS in the prefrontal cortex, hippocampus, hypothalamus, and blood were associated with inflammatory and immune responses. A machine-learning approach controlling for unspecific UCMS effects identified transcriptomic predictor sets for REMS parameters that were enriched in 193 pathways, including some involved in stem cells, immune response, and apoptosis and survival. Only three pathways were enriched in predictor sets for non-REMS. Transcriptomic predictor sets for variation in REMS continuity and theta activity shared many pathways with corticosterone regulation, in particular pathways implicated in apoptosis and survival, including mitochondrial apoptotic machinery. Predictor sets for REMS and anhedonia shared pathways involved in oxidative stress, cell proliferation, and apoptosis. These data identify REMS as a core and early element of the response to chronic stress, and identify apoptosis and survival pathways as a putative mechanism by which REMS may mediate the response to stressful waking experiences.
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Mazuski C, Abel JH, Chen SP, Hermanstyne TO, Jones JR, Simon T, Doyle FJ, Herzog ED. Entrainment of Circadian Rhythms Depends on Firing Rates and Neuropeptide Release of VIP SCN Neurons. Neuron 2018; 99:555-563.e5. [PMID: 30017392 PMCID: PMC6085153 DOI: 10.1016/j.neuron.2018.06.029] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 05/13/2018] [Accepted: 06/15/2018] [Indexed: 01/23/2023]
Abstract
The mammalian suprachiasmatic nucleus (SCN) functions as a master circadian pacemaker, integrating environmental input to align physiological and behavioral rhythms to local time cues. Approximately 10% of SCN neurons express vasoactive intestinal polypeptide (VIP); however, it is unknown how firing activity of VIP neurons releases VIP to entrain circadian rhythms. To identify physiologically relevant firing patterns, we optically tagged VIP neurons and characterized spontaneous firing over 3 days. VIP neurons had circadian rhythms in firing rate and exhibited two classes of instantaneous firing activity. We next tested whether physiologically relevant firing affected circadian rhythms through VIP release. We found that VIP neuron stimulation with high, but not low, frequencies shifted gene expression rhythms in vitro through VIP signaling. In vivo, high-frequency VIP neuron activation rapidly entrained circadian locomotor rhythms. Thus, increases in VIP neuronal firing frequency release VIP and entrain molecular and behavioral circadian rhythms. VIDEO ABSTRACT.
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Affiliation(s)
- Cristina Mazuski
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - John H Abel
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Samantha P Chen
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Tracey O Hermanstyne
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Jeff R Jones
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Tatiana Simon
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Francis J Doyle
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Erik D Herzog
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
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Landgraf D, Neumann AM, Oster H. Circadian clock-gastrointestinal peptide interaction in peripheral tissues and the brain. Best Pract Res Clin Endocrinol Metab 2017; 31:561-571. [PMID: 29224668 DOI: 10.1016/j.beem.2017.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Food intake and sleep are two mutually exclusive behaviors and both are normally confined to opposing phases of the diurnal cycle. The temporal coordination of behavior and physiology along the 24-h day-night cycle is organized by a network of circadian clocks that orchestrate transcriptional programs controlling cellular physiology. Many of the peptide hormones of the gastrointestinal tract are not only secreted in a circadian fashion, they can also affect circadian clock function in peripheral metabolic tissues and the brain, thus providing metabolic feedback to metabolic and neurobehavioral circuits. In this review, we summarize the current knowledge on this gastrointestinal peptide crosstalk and its potential role in the coordination of nutrition and the maintenance of metabolic homeostasis.
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Affiliation(s)
- Dominic Landgraf
- Department of Psychiatry, Ludwig Maximilian University of Munich, Germany
| | - Anne-Marie Neumann
- Institute of Neurobiology, Center of Brain, Behavior & Metabolism, University of Lübeck, Germany
| | - Henrik Oster
- Institute of Neurobiology, Center of Brain, Behavior & Metabolism, University of Lübeck, Germany.
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Abad C, Jayaram B, Becquet L, Wang Y, O’Dorisio MS, Waschek JA, Tan YV. VPAC1 receptor (Vipr1)-deficient mice exhibit ameliorated experimental autoimmune encephalomyelitis, with specific deficits in the effector stage. J Neuroinflammation 2016; 13:169. [PMID: 27357191 PMCID: PMC4928347 DOI: 10.1186/s12974-016-0626-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/14/2016] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Vasoactive intestinal peptide (VIP) and pituitary adenylyl cyclase-activating polypeptide (PACAP) are two highly homologous neuropeptides. In vitro and ex vivo experiments repeatedly demonstrate that these peptides exert pronounced immunomodulatory (primarily anti-inflammatory) actions which are mediated by common VPAC1 and VPAC2 G protein-coupled receptors. In agreement, we have shown that mice deficient in PACAP ligand or VPAC2 receptors exhibit exacerbated experimental autoimmune encephalomyelitis (EAE). However, we observed that VIP-deficient mice are unexpectedly resistant to EAE, suggesting a requirement for this peptide at some stage of disease development. Here, we investigated the involvement of VPAC1 in the development of EAE using a VPAC1-deficient mouse model. METHODS EAE was induced in wild-type (WT) and VPAC1 knockout (KO) mice using myelin oligodendrocyte glycoprotein 35-55 (MOG35-55), and clinical scores were assessed continuously over 30 days. Immune responses in the spinal cords were determined by histology, real-time PCR and immunofluorescence, and in the draining lymph nodes by antigen-recall assays. The contribution of VPAC1 expression in the immune system to the development of EAE was evaluated by means of adoptive transfer and bone marrow chimera experiments. In other experiments, VPAC1 receptor analogs were given to WT mice. RESULTS MOG35-55-induced EAE was ameliorated in VPAC1 KO mice compared to WT mice. The EAE-resistant phenotype of VPAC1 KO mice correlated with reduced central nervous system (CNS) histopathology and cytokine expression in the spinal cord. The immunization phase of EAE appeared to be unimpaired because lymph node cells from EAE-induced VPAC1 KO mice stimulated in vitro with MOG exhibited robust proliferative and Th1/Th17 responses. Moreover, lymph node and spleen cells from KO mice were fully capable of inducing EAE upon transfer to WT recipients. In contrast, WT cells from MOG-immunized mice did not transfer the disease when administered to VPAC1 KO recipients, implicating a defect in the effector phase of the disease. Bone marrow chimera studies suggested that the resistance of VPAC1-deficient mice was only minimally dependent on the expression of this receptor in the immunogenic/hematopoietic compartment. Consistent with this, impaired spinal cord inductions of several chemokine mRNAs were observed in VPAC1 KO mice. Finally, treatment of WT mice with the VPAC1 receptor antagonist PG97-269 before, but not after, EAE induction mimicked the clinical phenotype of VPAC1 KO mice. CONCLUSIONS VPAC1 gene loss impairs the development of EAE in part by preventing an upregulation of CNS chemokines and invasion of inflammatory cells into the CNS. Use of VPAC1 antagonists in WT mice prior to EAE induction also support a critical role for VPAC1 signaling for the development of EAE.
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MESH Headings
- Adoptive Transfer
- Animals
- Central Nervous System/immunology
- Central Nervous System/metabolism
- Central Nervous System/pathology
- Cytokines/genetics
- Cytokines/metabolism
- Disease Models, Animal
- Encephalomyelitis, Autoimmune, Experimental/chemically induced
- Encephalomyelitis, Autoimmune, Experimental/complications
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Female
- Freund's Adjuvant/toxicity
- Laminin/metabolism
- Lymph Nodes/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myelin-Oligodendrocyte Glycoprotein/toxicity
- Peptide Fragments/toxicity
- RNA, Messenger/metabolism
- Receptors, Vasoactive Intestinal Polypeptide, Type I/deficiency
- Receptors, Vasoactive Intestinal Polypeptide, Type I/genetics
- Spinal Cord/metabolism
- Spinal Cord/pathology
- Th1 Cells/metabolism
- Th1 Cells/pathology
- Th17 Cells/metabolism
- Th17 Cells/pathology
- Time Factors
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Affiliation(s)
- Catalina Abad
- />Department of Psychiatry, David Geffen School of Medicine, University of California, Los Angeles, USA
- />Inserm U905, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen, Normandy, France
| | - Bhavaani Jayaram
- />Department of Psychiatry, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Laurine Becquet
- />Inserm U905, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen, Normandy, France
| | - Yuki Wang
- />Department of Psychiatry, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - M Sue O’Dorisio
- />Department of Pediatrics and Holden Comprehensive Cancer Center, RJ and LA Carver College of Medicine, University of Iowa, Iowa City, 52242 IA USA
| | - James A. Waschek
- />Department of Psychiatry, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Yossan-Var Tan
- />Department of Psychiatry, David Geffen School of Medicine, University of California, Los Angeles, USA
- />Inserm U905, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen, Normandy, France
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20
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Pilorz V, Tam SKE, Hughes S, Pothecary CA, Jagannath A, Hankins MW, Bannerman DM, Lightman SL, Vyazovskiy VV, Nolan PM, Foster RG, Peirson SN. Melanopsin Regulates Both Sleep-Promoting and Arousal-Promoting Responses to Light. PLoS Biol 2016; 14:e1002482. [PMID: 27276063 PMCID: PMC4898879 DOI: 10.1371/journal.pbio.1002482] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 05/13/2016] [Indexed: 11/30/2022] Open
Abstract
Light plays a critical role in the regulation of numerous aspects of physiology and behaviour, including the entrainment of circadian rhythms and the regulation of sleep. These responses involve melanopsin (OPN4)-expressing photosensitive retinal ganglion cells (pRGCs) in addition to rods and cones. Nocturnal light exposure in rodents has been shown to result in rapid sleep induction, in which melanopsin plays a key role. However, studies have also shown that light exposure can result in elevated corticosterone, a response that is not compatible with sleep. To investigate these contradictory findings and to dissect the relative contribution of pRGCs and rods/cones, we assessed the effects of light of different wavelengths on behaviourally defined sleep. Here, we show that blue light (470 nm) causes behavioural arousal, elevating corticosterone and delaying sleep onset. By contrast, green light (530 nm) produces rapid sleep induction. Compared to wildtype mice, these responses are altered in melanopsin-deficient mice (Opn4-/-), resulting in enhanced sleep in response to blue light but delayed sleep induction in response to green or white light. We go on to show that blue light evokes higher Fos induction in the SCN compared to the sleep-promoting ventrolateral preoptic area (VLPO), whereas green light produced greater responses in the VLPO. Collectively, our data demonstrates that nocturnal light exposure can have either an arousal- or sleep-promoting effect, and that these responses are melanopsin-mediated via different neural pathways with different spectral sensitivities. These findings raise important questions relating to how artificial light may alter behaviour in both the work and domestic setting. Light can produce either sleep or arousal in mice. This study reveals that these opposing effects depend upon the wavelength of light and appear to involve separate pathways, both modulated by the photopigment melanopsin. Light exerts profound effects on our physiology and behaviour, setting our biological clocks to the correct time and regulating when we are asleep and we are awake. The photoreceptors mediating these responses include the rods and cones involved in vision, as well as a subset of photosensitive retinal ganglion cells (pRGCs) expressing the blue light-sensitive photopigment melanopsin. Previous studies have shown that mice lacking melanopsin show impaired sleep in response to light. However, other studies have shown that light increases glucocorticoid release—a response typically associated with stress. To address these contradictory findings, we studied the responses of mice to light of different colours. We found that blue light was aversive, delaying sleep onset and increasing glucocorticoid levels. By contrast, green light led to rapid sleep onset. These different behavioural effects appear to be driven by different neural pathways. Surprisingly, both responses were impaired in mice lacking melanopsin. These data show that light can promote either sleep or arousal. Moreover, they provide the first evidence that melanopsin directly mediates the effects of light on glucocorticoids. This work shows the extent to which light affects our physiology and has important implications for the design and use of artificial light sources.
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Affiliation(s)
- Violetta Pilorz
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Shu K. E. Tam
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Steven Hughes
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Carina A. Pothecary
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Aarti Jagannath
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Mark W. Hankins
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - David M. Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Stafford L. Lightman
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom
| | - Vladyslav V. Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Patrick M. Nolan
- MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom
| | - Russell G. Foster
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail: (SNP); (RGF)
| | - Stuart N. Peirson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail: (SNP); (RGF)
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21
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Engeland WC, Yoder JM, Karsten CA, Kofuji P. Phase-Dependent Shifting of the Adrenal Clock by Acute Stress-Induced ACTH. Front Endocrinol (Lausanne) 2016; 7:81. [PMID: 27445984 PMCID: PMC4925674 DOI: 10.3389/fendo.2016.00081] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/20/2016] [Indexed: 01/23/2023] Open
Abstract
The adrenal cortex has a molecular clock that generates circadian rhythms in glucocorticoid production, yet it is unclear how the clock responds to acute stress. We hypothesized that stress-induced ACTH provides a signal that phase shifts the adrenal clock. To assess whether acute stress phase shifts the adrenal clock in vivo in a phase-dependent manner, mPER2:LUC mice on a 12:12-h light:dark cycle underwent restraint stress for 15 min or no stress at zeitgeber time (ZT) 2 (early subjective day) or at ZT16 (early subjective night). Adrenal explants from mice stressed at ZT2 showed mPER2:LUC rhythms that were phase-advanced by ~2 h, whereas adrenals from mice stressed at ZT16 showed rhythms that were phase-delayed by ~2 h. The biphasic response was also observed in mice injected subcutaneously either with saline or with ACTH at ZT2 or ZT16. Blockade of the ACTH response with the glucocorticoid, dexamethasone, prevented restraint stress-induced phase shifts in the mPER2:LUC rhythm both at ZT2 and at ZT16. The finding that acute stress results in a phase-dependent shift in the adrenal mPER2:LUC rhythm that can be blocked by dexamethasone indicates that stress-induced effectors, including ACTH, act to phase shift the adrenal clock rhythm.
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Affiliation(s)
- William C Engeland
- Department of Neuroscience, University of Minnesota , Minneapolis, MN , USA
| | - J Marina Yoder
- Department of Neuroscience, University of Minnesota , Minneapolis, MN , USA
| | - Carley A Karsten
- Department of Neuroscience, University of Minnesota , Minneapolis, MN , USA
| | - Paulo Kofuji
- Department of Neuroscience, University of Minnesota , Minneapolis, MN , USA
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22
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Houben T, Coomans CP, Meijer JH. Regulation of circadian and acute activity levels by the murine suprachiasmatic nuclei. PLoS One 2014; 9:e110172. [PMID: 25295522 PMCID: PMC4190325 DOI: 10.1371/journal.pone.0110172] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/17/2014] [Indexed: 12/15/2022] Open
Abstract
The suprachiasmatic nuclei (SCN) coordinate the daily sleep-wake cycle by generating a circadian rhythm in electrical impulse frequency. While period and phase of the SCN rhythm have been considered as major output parameters, we propose that the waveform of the rhythm of the SCN also has significance. Using implanted micro-electrodes, we recorded SCN impulse frequency in freely moving mice and manipulated its circadian waveform by exposing mice to light-dark (LD) cycle durations ranging from 22 hours (LD 11∶11) to 26 hours (LD 13∶13). Adaptation to long T-cycles (>24 h) resulted in a trough in electrical activity at the beginning of the night while in short T-cycles (<24 h), SCN activity reached a trough at the end of night. In all T-cycle durations, the intensity of behavioral activity was maximal during the trough of SCN electrical activity and correlated negatively with increasing levels of SCN activity. Interestingly, small changes in T-cycle duration could induce large changes in waveform and in the time of trough (about 3.5 h), and accordingly in the timing of behavioral activity. At a smaller timescale (minutes to hours), we observed a negative correlation between SCN activity and behavioral activity, and acute silencing of SCN neurons by tetrodotoxin (TTX) during the inactive phase of the animal triggered behavioral activity. Thus, the SCN electrical activity levels appear crucially involved in determining the temporal profile of behavioral activity and controls behavior beyond the circadian time domain.
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Affiliation(s)
- Thijs Houben
- Department of Molecular Cell Biology, Laboratory for Neurophysiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Claudia P. Coomans
- Department of Molecular Cell Biology, Laboratory for Neurophysiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Johanna H. Meijer
- Department of Molecular Cell Biology, Laboratory for Neurophysiology, Leiden University Medical Center, Leiden, the Netherlands
- * E-mail:
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23
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Loh DH, Kuljis DA, Azuma L, Wu Y, Truong D, Wang HB, Colwell CS. Disrupted reproduction, estrous cycle, and circadian rhythms in female mice deficient in vasoactive intestinal peptide. J Biol Rhythms 2014; 29:355-69. [PMID: 25252712 DOI: 10.1177/0748730414549767] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The female reproductive cycle is gated by the circadian timing system and may be vulnerable to disruptions in the circadian system. Prior work suggests that vasoactive intestinal peptide (VIP)-expressing neurons in the suprachiasmatic nucleus (SCN) are one pathway by which the circadian clock can influence the estrous cycle, but the impact of the loss of this peptide on reproduction has not been assessed. In the present study, we first examine the impact of the genetic loss of the neuropeptide VIP on the reproductive success of female mice. Significantly, mutant females produce about half the offspring of their wild-type sisters even when mated to the same males. We also find that VIP-deficient females exhibit a disrupted estrous cycle; that is, ovulation occurs less frequently and results in the release of fewer oocytes compared with controls. Circadian rhythms of wheel-running activity are disrupted in the female mutant mice, as is the spontaneous electrical activity of dorsal SCN neurons. On a molecular level, the VIP-deficient SCN tissue exhibits lower amplitude oscillations with altered phase relationships between the SCN and peripheral oscillators as measured by PER2-driven bioluminescence. The simplest explanation of our data is that the loss of VIP results in a weakened SCN oscillator, which reduces the synchronization of the female circadian system. These results clarify one of the mechanisms by which disruption of the circadian system reduces female reproductive success.
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Affiliation(s)
- D H Loh
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry and Biobehavioral Sciences, University of California-Los Angeles, California
| | - D A Kuljis
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry and Biobehavioral Sciences, University of California-Los Angeles, California Department of Neurobiology, University of California-Los Angeles
| | - L Azuma
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry and Biobehavioral Sciences, University of California-Los Angeles, California
| | - Y Wu
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry and Biobehavioral Sciences, University of California-Los Angeles, California
| | - D Truong
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry and Biobehavioral Sciences, University of California-Los Angeles, California
| | - H B Wang
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry and Biobehavioral Sciences, University of California-Los Angeles, California
| | - C S Colwell
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry and Biobehavioral Sciences, University of California-Los Angeles, California
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25
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Kiessling S, Sollars PJ, Pickard GE. Light stimulates the mouse adrenal through a retinohypothalamic pathway independent of an effect on the clock in the suprachiasmatic nucleus. PLoS One 2014; 9:e92959. [PMID: 24658072 PMCID: PMC3962469 DOI: 10.1371/journal.pone.0092959] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 02/27/2014] [Indexed: 01/13/2023] Open
Abstract
The brain's master circadian pacemaker resides within the hypothalamic suprachiasmatic nucleus (SCN). SCN clock neurons are entrained to the day/night cycle via the retinohypothalamic tract and the SCN provides temporal information to the central nervous system and to peripheral organs that function as secondary oscillators. The SCN clock-cell network is thought to be the hypothalamic link between the retina and descending autonomic circuits to peripheral organs such as the adrenal gland, thereby entraining those organs to the day/night cycle. However, there are at least three different routes or mechanisms by which retinal signals transmitted to the hypothalamus may be conveyed to peripheral organs: 1) via retinal input to SCN clock neurons; 2) via retinal input to non-clock neurons in the SCN; or 3) via retinal input to hypothalamic regions neighboring the SCN. It is very well documented that light-induced responses of the SCN clock (i.e., clock gene expression, neural activity, and behavioral phase shifts) occur primarily during the subjective night. Thus to determine the role of the SCN clock in transmitting photic signals to descending autonomic circuits, we compared the phase dependency of light-evoked responses in the SCN and a peripheral oscillator, the adrenal gland. We observed light-evoked clock gene expression in the mouse adrenal throughout the subjective day and subjective night. Light also induced adrenal corticosterone secretion during both the subjective day and subjective night. The irradiance threshold for light-evoked adrenal responses was greater during the subjective day compared to the subjective night. These results suggest that retinohypothalamic signals may be relayed to the adrenal clock during the subjective day by a retinal pathway or cellular mechanism that is independent of an effect of light on the SCN neural clock network and thus may be important for the temporal integration of physiology and metabolism.
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Affiliation(s)
- Silke Kiessling
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
- Douglas Mental Health University Institute, McGill University, Montreal, Quebec, Canada
| | - Patricia J. Sollars
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Gary E. Pickard
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail:
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Yoder JM, Brandeland M, Engeland WC. Phase-dependent resetting of the adrenal clock by ACTH in vitro. Am J Physiol Regul Integr Comp Physiol 2014; 306:R387-93. [PMID: 24477539 DOI: 10.1152/ajpregu.00519.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The adrenal cortex has a molecular clock that generates circadian rhythms in glucocorticoids, yet how the clock is synchronized to the external environment is unknown. Using mPER2::Luciferase (mPER2Luc) knockin mice, in which luciferase is rhythmically expressed under the control of the mouse Per2 clock gene, we hypothesized that ACTH transmits entrainment signals to the adrenal. Adrenal explants were administered ACTH at different phases of the mPER2Luc rhythm. Treatment with ACTH 1-39 produced a phase delay that was phase-dependent, with a maximum at circadian time (CT)18; ACTH did not alter the period or amplitude of the rhythm. Forskolin produced a parallel response, suggesting that the phase delay was cAMP-mediated. The response to ACTH was concentration-dependent and peptide-specific. Pulse administration (60 min) of ACTH 1-39 also produced phase delays restricted to late CTs. In contrast to ACTH 1-39, other ACTH fragments, including α-melanocyte-stimulating hormone, which do not activate the melanocortin 2 (MC2/ACTH) receptor, had no effect. The finding that ACTH in vitro phase delays the adrenal mPER2luc rhythm in a monophasic fashion argues for ACTH as a key resetter, but not the sole entrainer, of the adrenal clock.
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Affiliation(s)
- J Marina Yoder
- Department of Neuroscience, University of Minnesota, Minneapolis, Minneapolis
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Zelinski EL, Deibel SH, McDonald RJ. The trouble with circadian clock dysfunction: multiple deleterious effects on the brain and body. Neurosci Biobehav Rev 2014; 40:80-101. [PMID: 24468109 DOI: 10.1016/j.neubiorev.2014.01.007] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 01/07/2014] [Accepted: 01/16/2014] [Indexed: 02/08/2023]
Abstract
This review consolidates research employing human correlational and experimental work across brain and body with experimental animal models to provide a more complete representation of how circadian rhythms influence almost all aspects of life. In doing so, we will cover the morphological and biochemical pathways responsible for rhythm generation as well as interactions between these systems and others (e.g., stress, feeding, reproduction). The effects of circadian disruption on the health of humans, including time of day effects, cognitive sequelae, dementia, Alzheimer's disease, diet, obesity, food preferences, mood disorders, and cancer will also be discussed. Subsequently, experimental support for these largely correlational human studies conducted in non-human animal models will be described.
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Affiliation(s)
- Erin L Zelinski
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada.
| | - Scott H Deibel
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
| | - Robert J McDonald
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
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Yulyaningsih E, Loh K, Lin S, Lau J, Zhang L, Shi Y, Berning BA, Enriquez R, Driessler F, Macia L, Khor EC, Qi Y, Baldock P, Sainsbury A, Herzog H. Pancreatic polypeptide controls energy homeostasis via Npy6r signaling in the suprachiasmatic nucleus in mice. Cell Metab 2014; 19:58-72. [PMID: 24411939 DOI: 10.1016/j.cmet.2013.11.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 10/04/2013] [Accepted: 11/15/2013] [Indexed: 12/29/2022]
Abstract
Y-receptors control energy homeostasis, but the role of Npy6 receptors (Npy6r) is largely unknown. Young Npy6r-deficient (Npy6r(-/-)) mice have reduced body weight, lean mass, and adiposity, while older and high-fat-fed Npy6r(-/-) mice have low lean mass with increased adiposity. Npy6r(-/-) mice showed reduced hypothalamic growth hormone releasing hormone (Ghrh) expression and serum insulin-like growth factor-1 (IGF-1) levels relative to WT. This is likely due to impaired vasoactive intestinal peptide (VIP) signaling in the suprachiasmatic nucleus (SCN), where we found Npy6r coexpressed in VIP neurons. Peripheral administration of pancreatic polypeptide (PP) increased Fos expression in the SCN, increased energy expenditure, and reduced food intake in WT, but not Npy6r(-/-), mice. Moreover, intraperitoneal (i.p.) PP injection increased hypothalamic Ghrh mRNA expression and serum IGF-1 levels in WT, but not Npy6r(-/-), mice, an effect blocked by intracerebroventricular (i.c.v.) Vasoactive Intestinal Peptide (VPAC) receptors antagonism. Thus, PP-initiated signaling through Npy6r in VIP neurons regulates the growth hormone axis and body composition.
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Affiliation(s)
- Ernie Yulyaningsih
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Kim Loh
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Shu Lin
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Jackie Lau
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Lei Zhang
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Yanchuan Shi
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Britt A Berning
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Ronaldo Enriquez
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Frank Driessler
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Laurence Macia
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Ee Cheng Khor
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Yue Qi
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Paul Baldock
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia
| | - Amanda Sainsbury
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia; School of Medical Sciences, Wallace Wurth Building, University of NSW, Botany Street, Sydney 2052, Australia; The Boden Institute of Obesity, Nutrition, Exercise, and Eating Disorders, Sydney Medical School, The University of Sydney, Medical Foundation Building, 92-94 Parramatta Road, Camperdown NSW 2006, Australia
| | - Herbert Herzog
- Neuroscience Program, Garvan Institute of Medical Research, St. Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney NSW 2010, Australia; UNSW Medicine, ASGM Building, University of NSW, Botany Street, Sydney 2052, Australia.
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Wotus C, Lilley TR, Neal AS, Suleiman NL, Schmuck SC, Smarr BL, Fischer BJ, de la Iglesia HO. Forced desynchrony reveals independent contributions of suprachiasmatic oscillators to the daily plasma corticosterone rhythm in male rats. PLoS One 2013; 8:e68793. [PMID: 23894346 PMCID: PMC3718825 DOI: 10.1371/journal.pone.0068793] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 06/04/2013] [Indexed: 11/18/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) is required for the daily rhythm of plasma glucocorticoids; however, the independent contributions from oscillators within the different subregions of the SCN to the glucocorticoid rhythm remain unclear. Here, we use genetically and neurologically intact, forced desynchronized rats to test the hypothesis that the daily rhythm of the glucocorticoid, corticosterone, is regulated by both light responsive and light-dissociated circadian oscillators in the ventrolateral (vl-) and dorsomedial (dm-) SCN, respectively. We show that when the vlSCN and dmSCN are in maximum phase misalignment, the peak of the plasma corticosterone rhythm is shifted and the amplitude reduced; whereas, the peak of the plasma adrenocorticotropic hormone (ACTH) rhythm is also reduced, the phase is dissociated from that of the corticosterone rhythm. These data support previous studies suggesting an ACTH-independent pathway contributes to the corticosterone rhythm. To determine if either SCN subregion independently regulates corticosterone through the sympathetic nervous system, we compared unilateral adrenalectomized, desynchronized rats that had undergone either transection of the thoracic splanchnic nerve or sham transection to the remaining adrenal. Splanchnicectomy reduced and phase advanced the peak of both the corticosterone and ACTH rhythms. These data suggest that both the vlSCN and dmSCN contribute to the corticosterone rhythm by both reducing plasma ACTH and differentially regulating plasma corticosterone through an ACTH- and sympathetic nervous system-independent pathway.
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Affiliation(s)
- Cheryl Wotus
- Department of Biology, Seattle University, Seattle, Washington, USA.
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An S, Tsai C, Ronecker J, Bayly A, Herzog ED. Spatiotemporal distribution of vasoactive intestinal polypeptide receptor 2 in mouse suprachiasmatic nucleus. J Comp Neurol 2013; 520:2730-41. [PMID: 22684939 DOI: 10.1002/cne.23078] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Vasoactive intestinal polypeptide (VIP) signaling is critical for circadian rhythms. For example, the expression of VIP and its main receptor, VPAC2R, is necessary for maintaining synchronous daily rhythms among neurons in the suprachiasmatic nucleus (SCN), a master circadian pacemaker in animals. Where and when VPAC2R protein is expressed in the SCN and other brain areas has not been examined. Using immunohistochemistry, we characterized a new antibody and found that VPAC2R was highly enriched in the SCN and detectable at low levels in many brain areas. Within the SCN, VPAC2R was circadian, peaking in the subjective morning, and abundantly expressed from the rostral to caudal margins with more in the dorsomedial than ventrolateral area. VPAC2R was found in nearly all SCN cells including neurons expressing either VIP or vasopressin (AVP). SCN neurons mainly expressed VPAC2R in their somata and dendrites, not axons. Finally, constant light increased VIP and AVP expression, but not VPAC2R. We conclude that the circadian clock, not the ambient light level, regulates VPAC2R protein localization. These results are consistent with VPAC2R playing a role in VIP signaling at all times of day, broadly throughout the brain and in all SCN cells.
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Affiliation(s)
- Sungwon An
- Department of Biology, Washington University, Saint Louis, Missouri 63130, USA
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Xu CX, Wang C, Krager SL, Bottum KM, Tischkau SA. Aryl hydrocarbon receptor activation attenuates Per1 gene induction and influences circadian clock resetting. Toxicol Sci 2013; 132:368-78. [PMID: 23291558 DOI: 10.1093/toxsci/kfs345] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Light-stimulated adjustment of the circadian clock is an important adaptive physiological response that allows maintenance of behavioral synchrony with solar time. Our previous studies indicate that the aryl hydrocarbon receptor (AhR) agonist 2,3,7,8- tetrachlorodibenzo-p-dioxin attenuates light-induced phase resetting in early night. However, the mechanism of inhibition remains unclear. In this study, we showed that another potent AhR agonist-β-naphthoflavone (BNF)-significantly decreased light-induced phase shifts in wild-type (WT) mice, whereas AhR knockout mice had an enhanced response to light that was unaffected by BNF. Mechanistically, BNF blocked light induction of the Per1 transcript in suprachiasmatic nucleus and liver in WT mice, and BNF blocked forskolin (FSK)-induced Per1 transcripts in Hepa-1c1c7 (c7) cells. An E-box decoy did not affect BNF inhibition of FSK-induced Per1 transcripts in c7 cells. cAMP-response element (CRE)-dependent induction of Per1 promoter activity in response to FSK in combination with phorbol 12-tetradecanoate 13-acetate was suppressed in cells that expressed high levels of AhR (c7) compared with cells lacking functional AhR activity (c12). In addition, the inhibitory effect of BNF on FSK-induced Per1 was dependent on phosphorylation of JNK. Together, these results suggest that AhR activation inhibits light-induced phase resetting through the activation of JNK, negative regulation of CREs in the Per1 promoter, and suppression of Per1.
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Affiliation(s)
- Can-Xin Xu
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62702, USA
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Abstract
The highly coordinated output of the hypothalamic biological clock does not only govern the daily rhythm in sleep/wake (or feeding/fasting) behaviour but also has direct control over many aspects of hormone release. In fact, a significant proportion of our current understanding of the circadian clock has its roots in the study of the intimate connections between the hypothalamic clock and multiple endocrine axes. This chapter will focus on the anatomical connections used by the mammalian biological clock to enforce its endogenous rhythmicity on the rest of the body, using a number of different hormone systems as a representative example. Experimental studies have revealed a highly specialised organisation of the connections between the mammalian circadian clock neurons and neuroendocrine as well as pre-autonomic neurons in the hypothalamus. These complex connections ensure a logical coordination between behavioural, endocrine and metabolic functions that will help the organism adjust to the time of day most efficiently. For example, activation of the orexin system by the hypothalamic biological clock at the start of the active phase not only ensures that we wake up on time but also that our glucose metabolism and cardiovascular system are prepared for this increased activity. Nevertheless, it is very likely that the circadian clock present within the endocrine glands plays a significant role as well, for instance, by altering these glands' sensitivity to specific stimuli throughout the day. In this way the net result of the activity of the hypothalamic and peripheral clocks ensures an optimal endocrine adaptation of the metabolism of the organism to its time-structured environment.
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Affiliation(s)
- Andries Kalsbeek
- Department of Endocrinology and Metabolism, G2-133, Academic Medical Center of the University of Amsterdam, The Netherlands.
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Fahrenkrug J, Georg B, Hannibal J, Jørgensen HL. Altered rhythm of adrenal clock genes, StAR and serum corticosterone in VIP receptor 2-deficient mice. J Mol Neurosci 2012; 48:584-96. [PMID: 22622901 DOI: 10.1007/s12031-012-9804-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 05/03/2012] [Indexed: 12/31/2022]
Abstract
The circadian time-keeping system consists of clocks in the suprachiasmatic nucleus (SCN) and in peripheral organs including an adrenal clock linked to the rhythmic corticosteroid production by regulating steroidogenic acute regulatory protein (StAR). Clock cells contain an autonomous molecular oscillator based on a group of clock genes and their protein products. Mice lacking the VPAC2 receptor display disrupted circadian rhythm of physiology and behaviour, and therefore, we using real-time RT-PCR quantified (1) the mRNAs for the clock genes Per1 and Bmal1 in the adrenal gland and SCN, (2) the adrenal Star mRNA and (3) the serum corticosterone concentration both during a light/dark (L/D) cycle and at constant darkness in wild type (WT) and VPAC2 receptor-deficient mice (VPAC2-KO). We also examined if PER1 and StAR were co-localised in the adrenal steroidogenic cells. Per1 and Bmal1 mRNA showed a 24-h rhythmic expression in the adrenal of WT mice under L/D and dark conditions. During a L/D cycle, the adrenal clock gene rhythm in VPAC2-KO mice was phase-advanced by approximately 6 h compared to WT mice and became arrhythmic in constant darkness. A significant 24-h rhythmic variation in the adrenal Star mRNA expression and circulating corticosterone concentration was similarly phase-advanced during the L/D cycle. The loss of adrenal clock gene rhythm in the VPAC2 receptor knockout mice after transfer into constant darkness was accompanied by disappearance of rhythmicity in Star mRNA expression and serum corticosterone concentration. Double immunohistochemistry showed that the PER1 protein and StAR were co-localised in the same steroidogenic cells. Circulating corticosterone plays a role in the circadian timing system and the misaligned corticosterone rhythm in the VPAC2 receptor knockout mice could be involved in their abnormal rhythms of physiology.
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Affiliation(s)
- Jan Fahrenkrug
- Department of Clinical Biochemistry, Bispebjerg Hospital, University of Copenhagen, Copenhagen 2400, Denmark.
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34
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Granados-Fuentes D, Herzog ED. The clock shop: coupled circadian oscillators. Exp Neurol 2012; 243:21-7. [PMID: 23099412 DOI: 10.1016/j.expneurol.2012.10.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 09/04/2012] [Accepted: 10/16/2012] [Indexed: 01/10/2023]
Abstract
Daily rhythms in neural activity underlie circadian rhythms in sleep-wake and other daily behaviors. The cells within the mammalian suprachiasmatic nucleus (SCN) are intrinsically capable of 24-h timekeeping. These cells synchronize with each other and with local environmental cycles to drive coherent rhythms in daily behaviors. Recent studies have identified a small number of neuropeptides critical for this ability to synchronize and sustain coordinated daily rhythms. This review highlights the roles of specific intracellular and intercellular signals within the SCN that underlie circadian synchrony.
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35
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Wong CCP, Schumann G. Integration of the circadian and stress systems: influence of neuropeptides and implications for alcohol consumption. J Neural Transm (Vienna) 2012; 119:1111-20. [PMID: 22648536 DOI: 10.1007/s00702-012-0829-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 05/10/2012] [Indexed: 12/16/2022]
Abstract
Disruptions in circadian rhythm and stress reactivity are associated with risks of developing neuropsychiatric disorders. The circadian system is organised in a hierarchical manner, whereby the master clock is located at the suprachiasmatic nucleus, a highly conserved brain region that coordinates the oscillations of peripheral clocks. Exposure to psychological stress leads to activation of the hypothalamic-pituitary-adrenal axis. There is growing evidence supporting the interactions between the circadian and stress systems. Anatomically, the circadian and stress signals converge at the paraventricular nucleus (PVN) in the hypothalamus. Genes that are involved in the operation of the circadian and stress systems, including Clock, Period and CRH are expressed in the PVN. In addition, several neuropeptides, including arginin-vasopressin, vasoactive intestinal polypeptide, pituitary adenylate cyclase-activating polypeptide and the neurotransmitter gamma-aminobutyric acid, are present in the PVN. In this review, we will discuss the interaction of circadian genes and stress-response genes at the molecular, neurotransmission and behavioural levels. We will place particular emphasis on the role of neuropeptides in mediating this interaction.
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Affiliation(s)
- Cybele C P Wong
- MRC-SGDP Centre, Institute of Psychiatry, King's College London, 16 De Crespigny Park, London SE5 8AF, UK.
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Punia S, Rumery KK, Yu EA, Lambert CM, Notkins AL, Weaver DR. Disruption of gene expression rhythms in mice lacking secretory vesicle proteins IA-2 and IA-2β. Am J Physiol Endocrinol Metab 2012; 303:E762-76. [PMID: 22785238 PMCID: PMC3468428 DOI: 10.1152/ajpendo.00513.2011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulinoma-associated protein (IA)-2 and IA-2β are transmembrane proteins involved in neurotransmitter secretion. Mice with targeted disruption of both IA-2 and IA-2β (double-knockout, or DKO mice) have numerous endocrine and physiological disruptions, including disruption of circadian and diurnal rhythms. In the present study, we have assessed the impact of disruption of IA-2 and IA-2β on molecular rhythms in the brain and peripheral oscillators. We used in situ hybridization to assess molecular rhythms in the hypothalamic suprachiasmatic nuclei (SCN) of wild-type (WT) and DKO mice. The results indicate significant disruption of molecular rhythmicity in the SCN, which serves as the central pacemaker regulating circadian behavior. We also used quantitative PCR to assess gene expression rhythms in peripheral tissues of DKO, single-knockout, and WT mice. The results indicate significant attenuation of gene expression rhythms in several peripheral tissues of DKO mice but not in either single knockout. To distinguish whether this reduction in rhythmicity reflects defective oscillatory function in peripheral tissues or lack of entrainment of peripheral tissues, animals were injected with dexamethasone daily for 15 days, and then molecular rhythms were assessed throughout the day after discontinuation of injections. Dexamethasone injections improved gene expression rhythms in liver and heart of DKO mice. These results are consistent with the hypothesis that peripheral tissues of DKO mice have a functioning circadian clockwork, but rhythmicity is greatly reduced in the absence of robust, rhythmic physiological signals originating from the SCN. Thus, IA-2 and IA-2β play an important role in the regulation of circadian rhythms, likely through their participation in neurochemical communication among SCN neurons.
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Affiliation(s)
- Sohan Punia
- Experimental Medicine Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
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Waite EJ, McKenna M, Kershaw Y, Walker JJ, Cho K, Piggins HD, Lightman SL. Ultradian corticosterone secretion is maintained in the absence of circadian cues. Eur J Neurosci 2012; 36:3142-50. [DOI: 10.1111/j.1460-9568.2012.08213.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lucassen EA, van Diepen HC, Houben T, Michel S, Colwell CS, Meijer JH. Role of vasoactive intestinal peptide in seasonal encoding by the suprachiasmatic nucleus clock. Eur J Neurosci 2012; 35:1466-74. [PMID: 22512278 DOI: 10.1111/j.1460-9568.2012.08054.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The neuropeptide vasoactive intestinal peptide (VIP) is critical for the proper functioning of the neural circuit that generates circadian rhythms. Mice lacking VIP show profound deficits in the ability to generate many behavioral and physiological rhythms. To explore how the loss of VIP impacts on the intact circadian system, we carried out in vivo multiunit neural activity (MUA) recordings from the suprachiasmatic nucleus of freely moving VIP knockout (KO) mice. The MUA rhythms were largely unaltered in the VIP KO mice, with no significant differences being seen in the amplitude or phase of the rhythms in light-dark conditions. Robust differences between the genotypes were revealed when the mice were transferred from light-dark to constant darkness conditions. In addition, the ability of the VIP KO mice to encode changes in photoperiod was examined. Strikingly, the behavioral and physiological rhythms of VIP KO mice showed no adaptation to short or long photoperiods. The data indicate that the intact circadian system can compensate for some of the consequences of the loss of VIP, whereas this peptide is indispensable for endogenous encoding of seasonal information.
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Affiliation(s)
- Eliane A Lucassen
- Laboratory of Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
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Kalsbeek A, van der Spek R, Lei J, Endert E, Buijs RM, Fliers E. Circadian rhythms in the hypothalamo-pituitary-adrenal (HPA) axis. Mol Cell Endocrinol 2012; 349:20-9. [PMID: 21782883 DOI: 10.1016/j.mce.2011.06.042] [Citation(s) in RCA: 255] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 06/29/2011] [Accepted: 06/30/2011] [Indexed: 01/06/2023]
Abstract
The pronounced daily variation in the release of adrenal hormones has been at the heart of the deciphering and understanding of the circadian timing system. Indeed, the first demonstration of an endocrine day/night rhythm was provided by Pincus (1943), by showing a daily pattern of 17-keto-steroid excretion in the urine of 7 healthy males. Twenty years later the adrenal gland was one of the very first organs to show, in vitro, that circadian rhythmicity was maintained. In the seventies, experimental manipulation of the daily corticosterone rhythm served as evidence for the identification of respectively the light- and food-entrainable oscillator. Another 20 years later the hypothalamo-pituitary-adrenal (HPA)-axis was key in furthering our understanding of the way in which rhythmic signals generated by the central pacemaker in the hypothalamic suprachiasmatic nuclei (SCN) are forwarded to the rest of the brain and to the organism as a whole. To date, the adrenal gland is still of prime importance for understanding how the oscillations of clock genes in peripheral tissues result in functional rhythms of these tissues, whereas it has become even more evident that adrenal glucocorticoids are key in the resetting of the circadian system after a phase-shift. The HPA-axis thus still is an excellent model for studying the transmission of circadian information in the body.
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Affiliation(s)
- A Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, The Netherlands.
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40
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Loh DH, Dragich JM, Kudo T, Schroeder AM, Nakamura TJ, Waschek JA, Block GD, Colwell CS. Effects of vasoactive intestinal peptide genotype on circadian gene expression in the suprachiasmatic nucleus and peripheral organs. J Biol Rhythms 2011; 26:200-9. [PMID: 21628547 PMCID: PMC3942163 DOI: 10.1177/0748730411401740] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The neuropeptide vasoactive intestinal polypeptide (VIP) has emerged as a key candidate molecule mediating the synchronization of rhythms in clock gene expression within the suprachiasmatic nucleus (SCN). In addition, neurons expressing VIP are anatomically well positioned to mediate communication between the SCN and peripheral oscillators. In this study, we examined the temporal expression profile of 3 key circadian genes: Per1, Per2 , and Bmal1 in the SCN, the adrenal glands and the liver of mice deficient for the Vip gene (VIP KO), and their wild-type counterparts. We performed these measurements in mice held in a light/dark cycle as well as in constant darkness and found that rhythms in gene expression were greatly attenuated in the VIP-deficient SCN. In the periphery, the impact of the loss of VIP varied with the tissue and gene measured. In the adrenals, rhythms in Per1 were lost in VIP-deficient mice, while in the liver, the most dramatic impact was on the phase of the diurnal expression rhythms. Finally, we examined the effects of the loss of VIP on ex vivo explants of the same central and peripheral oscillators using the PER2::LUC reporter system. The VIP-deficient mice exhibited low amplitude rhythms in the SCN as well as altered phase relationships between the SCN and the peripheral oscillators. Together, these data suggest that VIP is critical for robust rhythms in clock gene expression in the SCN and some peripheral organs and that the absence of this peptide alters both the amplitude of circadian rhythms as well as the phase relationships between the rhythms in the SCN and periphery.
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Affiliation(s)
- Dawn H. Loh
- Department of Psychiatry and Biobehavioral Sciences, University of California–Los Angeles, Los Angeles, CA
| | - Joanna M. Dragich
- Department of Psychiatry and Biobehavioral Sciences, University of California–Los Angeles, Los Angeles, CA
| | - Takashi Kudo
- Department of Psychiatry and Biobehavioral Sciences, University of California–Los Angeles, Los Angeles, CA
| | - Analyne M. Schroeder
- Department of Psychiatry and Biobehavioral Sciences, University of California–Los Angeles, Los Angeles, CA
| | - Takahiro J. Nakamura
- Department of Psychiatry and Biobehavioral Sciences, University of California–Los Angeles, Los Angeles, CA
| | - James A. Waschek
- Department of Psychiatry and Biobehavioral Sciences, University of California–Los Angeles, Los Angeles, CA
| | - Gene D. Block
- Department of Psychiatry and Biobehavioral Sciences, University of California–Los Angeles, Los Angeles, CA
| | - Christopher S. Colwell
- Department of Psychiatry and Biobehavioral Sciences, University of California–Los Angeles, Los Angeles, CA
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Hughes ATL, Guilding C, Piggins HD. Neuropeptide signaling differentially affects phase maintenance and rhythm generation in SCN and extra-SCN circadian oscillators. PLoS One 2011; 6:e18926. [PMID: 21559484 PMCID: PMC3084722 DOI: 10.1371/journal.pone.0018926] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 03/11/2011] [Indexed: 02/02/2023] Open
Abstract
Circadian rhythms in physiology and behavior are coordinated by the brain's dominant circadian pacemaker located in the suprachiasmatic nuclei (SCN) of the hypothalamus. Vasoactive intestinal polypeptide (VIP) and its receptor, VPAC(2), play important roles in the functioning of the SCN pacemaker. Mice lacking VPAC(2) receptors (Vipr2(-/-)) express disrupted behavioral and metabolic rhythms and show altered SCN neuronal activity and clock gene expression. Within the brain, the SCN is not the only site containing endogenous circadian oscillators, nor is it the only site of VPAC(2) receptor expression; both VPAC(2) receptors and rhythmic clock gene/protein expression have been noted in the arcuate (Arc) and dorsomedial (DMH) nuclei of the mediobasal hypothalamus, and in the pituitary gland. The functional role of VPAC(2) receptors in rhythm generation and maintenance in these tissues is, however, unknown. We used wild type (WT) and Vipr2(-/-) mice expressing a luciferase reporter (PER2::LUC) to investigate whether circadian rhythms in the clock gene protein PER2 in these extra-SCN tissues were compromised by the absence of the VPAC(2) receptor. Vipr2(-/-) SCN cultures expressed significantly lower amplitude PER2::LUC oscillations than WT SCN. Surprisingly, in Vipr2(-/-) Arc/ME/PT complex (Arc, median eminence and pars tuberalis), DMH and pituitary, the period, amplitude and rate of damping of rhythms were not significantly different to WT. Intriguingly, while we found WT SCN and Arc/ME/PT tissues to maintain a consistent circadian phase when cultured, the phase of corresponding Vipr2(-/-) cultures was reset by cull/culture procedure. These data demonstrate that while the main rhythm parameters of extra-SCN circadian oscillations are maintained in Vipr2(-/-) mice, the ability of these oscillators to resist phase shifts is compromised. These deficiencies may contribute towards the aberrant behavior and metabolism associated with Vipr2(-/-) animals. Further, our data indicate a link between circadian rhythm strength and the ability of tissues to resist circadian phase resetting.
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Affiliation(s)
- Alun T L Hughes
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom.
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Luque RM, Lin Q, Córdoba-Chacón J, Subbaiah PV, Buch T, Waisman A, Vankelecom H, Kineman RD. Metabolic impact of adult-onset, isolated, growth hormone deficiency (AOiGHD) due to destruction of pituitary somatotropes. PLoS One 2011; 6:e15767. [PMID: 21283519 PMCID: PMC3023710 DOI: 10.1371/journal.pone.0015767] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 11/26/2010] [Indexed: 01/06/2023] Open
Abstract
Growth hormone (GH) inhibits fat accumulation and promotes protein accretion, therefore the fall in GH observed with weight gain and normal aging may contribute to metabolic dysfunction. To directly test this hypothesis a novel mouse model of adult onset-isolated GH deficiency (AOiGHD) was generated by cross breeding rat GH promoter-driven Cre recombinase mice (Cre) with inducible diphtheria toxin receptor mice (iDTR) and treating adult Cre+/−,iDTR+/− offspring with DT to selectively destroy the somatotrope population of the anterior pituitary gland, leading to a reduction in circulating GH and IGF-I levels. DT-treated Cre−/−,iDTR+/− mice were used as GH-intact controls. AOiGHD improved whole body insulin sensitivity in both low-fat and high-fat fed mice. Consistent with improved insulin sensitivity, indirect calorimetry revealed AOiGHD mice preferentially utilized carbohydrates for energy metabolism, as compared to GH-intact controls. In high-fat, but not low-fat fed AOiGHD mice, fat mass increased, hepatic lipids decreased and glucose clearance and insulin output were impaired. These results suggest the age-related decline in GH helps to preserve systemic insulin sensitivity, and in the context of moderate caloric intake, prevents the deterioration in metabolic function. However, in the context of excess caloric intake, low GH leads to impaired insulin output, and thereby could contribute to the development of diabetes.
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Affiliation(s)
- Raul M. Luque
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, United States of America
- Department of Medicine, Section of Endocrinology, Diabetes and Metabolism, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain
| | - Qing Lin
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, United States of America
- Department of Medicine, Section of Endocrinology, Diabetes and Metabolism, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - José Córdoba-Chacón
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain
| | - Papasani V. Subbaiah
- Department of Medicine, Section of Endocrinology, Diabetes and Metabolism, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Thorsten Buch
- Neuroimmunology Division, Institute of Experimental Immunology, Department of Pathology, University Hospital Zürich, Zürich, Switzerland
| | - Ari Waisman
- Institute for Molecular Biology, University Medical Centre, University of Mainz, Mainz, Germany
| | - Hugo Vankelecom
- Laboratory of Tissue Plasticity, Department of Molecular Cell Biology, University of Leuven (K.U.Leuven), Leuven, Belgium
| | - Rhonda D. Kineman
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, United States of America
- Department of Medicine, Section of Endocrinology, Diabetes and Metabolism, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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Schroeder A, Loh DH, Jordan MC, Roos KP, Colwell CS. Circadian regulation of cardiovascular function: a role for vasoactive intestinal peptide. Am J Physiol Heart Circ Physiol 2010; 300:H241-50. [PMID: 20952671 DOI: 10.1152/ajpheart.00190.2010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The circadian system, driven by the suprachiasmatic nucleus (SCN), regulates properties of cardiovascular function. The dysfunction of this timing system can result in cardiac pathology. The neuropeptide vasoactive intestinal peptide (VIP) is crucial for circadian rhythms in a number of biological processes including SCN electrical activity and wheel running behavior. Anatomic evidence indicates that SCN neurons expressing VIP are well positioned to drive circadian regulation of cardiac function through interactions with the autonomic centers. In this study, we tested the hypothesis that loss of VIP would result in circadian deficits in heart rate (HR) and clock gene expression in cardiac tissue. We implanted radiotelemetry devices into VIP-deficient mice and wild-type (WT) controls and continuously recorded HR, body temperature, and cage activity in freely moving mice. Under light-dark conditions, VIP-deficient mice displayed weak rhythms in HR, body temperature, and cage activity, with onsets that were advanced in phase compared with WT mice. Similarly, clock gene expression in cardiac tissue was rhythmic but phase advanced in mutant mice. In constant darkness, the normal circadian rhythms in HR were lost in VIP-deficient mice; however, most mutant mice continued to exhibit circadian rhythms of body temperature with shortened free-running period. The loss of VIP altered, but did not abolish, autonomic regulation of HR. Analysis of the echocardiograms did not find any evidence for a loss of cardiac function in VIP-deficient mice, and the size of the hearts did not differ between genotypes. These results demonstrate that VIP is an important regulator of physiological circadian rhythmicity in the heart.
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Affiliation(s)
- Analyne Schroeder
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, California 90024, USA
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Duncan MJ, Hester JM, Hopper JA, Franklin KM. The effects of aging and chronic fluoxetine treatment on circadian rhythms and suprachiasmatic nucleus expression of neuropeptide genes and 5-HT1B receptors. Eur J Neurosci 2010; 31:1646-54. [PMID: 20525077 DOI: 10.1111/j.1460-9568.2010.07186.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Age-related changes in circadian rhythms, including attenuation of photic phase shifts, are associated with changes in the central pacemaker in the suprachiasmatic nucleus (SCN). Aging decreases expression of mRNA for vasoactive intestinal peptide (VIP), a key neuropeptide for rhythm generation and photic phase shifts, and increases expression of serotonin transporters and 5-HT(1B) receptors, whose activation inhibits these phase shifts. Here we describe studies in hamsters showing that aging decreases SCN expression of mRNA for gastrin-releasing peptide, which also modulates photic phase resetting. Because serotonin innervation trophically supports SCN VIP mRNA expression, and serotonin transporters decrease extracellular serotonin, we predicted that chronic administration of the serotonin-selective reuptake inhibitor, fluoxetine, would attenuate the age-related changes in SCN VIP mRNA expression and 5-HT(1B) receptors. In situ hybridization studies showed that fluoxetine treatment does not alter SCN VIP mRNA expression, in either age group, at zeitgeber time (ZT)6 or 13 (ZT12 corresponds to lights off). However, receptor autoradiographic studies showed that fluoxetine prevents the age-related increase in SCN 5-HT(1B) receptors at ZT6, and decreases SCN 5-HT(1B) receptors in both ages at ZT13. Therefore, aging effects on SCN VIP mRNA and SCN 5-HT(1B) receptors are differentially regulated; the age-related increase in serotonin transporter sites mediates the latter but not the former. The studies also showed that aging and chronic fluoxetine treatment decrease total daily wheel running without altering the phase of the circadian wheel running rhythm, in contrast to previous reports of phase resetting by acute fluoxetine treatment.
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Affiliation(s)
- Marilyn J Duncan
- Department of Anatomy and Neurobiology, University of Kentucky Medical Center, Lexington, KY 40536, USA.
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Loh DH, Navarro J, Hagopian A, Wang LM, Deboer T, Colwell CS. Rapid changes in the light/dark cycle disrupt memory of conditioned fear in mice. PLoS One 2010; 5. [PMID: 20824058 PMCID: PMC2932734 DOI: 10.1371/journal.pone.0012546] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 08/10/2010] [Indexed: 11/19/2022] Open
Abstract
Background Circadian rhythms govern many aspects of physiology and behavior including cognitive processes. Components of neural circuits involved in learning and memory, e.g., the amygdala and the hippocampus, exhibit circadian rhythms in gene expression and signaling pathways. The functional significance of these rhythms is still not understood. In the present study, we sought to determine the impact of transiently disrupting the circadian system by shifting the light/dark (LD) cycle. Such “jet lag” treatments alter daily rhythms of gene expression that underlie circadian oscillations as well as disrupt the synchrony between the multiple oscillators found within the body. Methodology/Principal Findings We subjected adult male C57Bl/6 mice to a contextual fear conditioning protocol either before or after acute phase shifts of the LD cycle. As part of this study, we examined the impact of phase advances and phase delays, and the effects of different magnitudes of phase shifts. Under all conditions tested, we found that recall of fear conditioned behavior was specifically affected by the jet lag. We found that phase shifts potentiated the stress-evoked corticosterone response without altering baseline levels of this hormone. The jet lag treatment did not result in overall sleep deprivation, but altered the temporal distribution of sleep. Finally, we found that prior experience of jet lag helps to compensate for the reduced recall due to acute phase shifts. Conclusions/Significance Acute changes to the LD cycle affect the recall of fear-conditioned behavior. This suggests that a synchronized circadian system may be broadly important for normal cognition and that the consolidation of memories may be particularly sensitive to disruptions of circadian timing.
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Affiliation(s)
- Dawn H. Loh
- Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California, United States of America
| | - Juliana Navarro
- Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California, United States of America
| | - Arkady Hagopian
- Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California, United States of America
| | - Louisa M. Wang
- Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California, United States of America
| | - Tom Deboer
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Christopher S. Colwell
- Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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Differential association of circadian genes with mood disorders: CRY1 and NPAS2 are associated with unipolar major depression and CLOCK and VIP with bipolar disorder. Neuropsychopharmacology 2010; 35:1279-89. [PMID: 20072116 PMCID: PMC3055337 DOI: 10.1038/npp.2009.230] [Citation(s) in RCA: 257] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Disruptions in circadian rhythms have been described in mood disorders (MD), but the involvement of genetic variation in genes pertaining to the molecular circadian machinery in the susceptibility to MD has not been conclusively determined. We examined 209 single-nucleotide polymorphisms (SNPs) covering 19 circadian genes (ADCYAP1, ARNTL, ARNTL2, BHLHB2, BHLHB3, CLOCK, CRY1, CRY2, CSNK1E, DBP, NPAS2, NR1D1, PER1, PER2, PER3, RORA, TIMELESS, VIP, and VIPR2) in a sample of 534 MD patients (335 with unipolar major mood depression (MDD) and 199 with bipolar disorder (BD)) and 440 community-based screened controls. Nominally, statistically significant associations were found in 15 circadian genes. The gene-wide test, corrected for the number of SNPs analyzed in each gene, identified significant associations in CRY1 (rs2287161), NPAS2 (rs11123857), and VIPR2 (rs885861) genes with the combined MD sample. In the MDD subsample, the same SNPs in CRY1 and NPAS2 of the combined sample remained associated, whereas in the BD subsample CLOCK (rs10462028) and VIP (rs17083008) were specifically associated. The association with an SNP located 3' near CRY1 gene in MDD remained statistically significant after permutation correction at experiment level (p=0.007). Significant additive effects were found between the SNPs that were statistically significant at the gene-wide level. We also found evidence of associations between two-marker haplotypes in CRY1 and NPAS2 genes and MD. Our data support the contribution of the circadian system to the genetic susceptibility to MD and suggest that different circadian genes may have specific effects on MD polarity.
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CRF-1 antagonist and CRF-2 agonist decrease binge-like ethanol drinking in C57BL/6J mice independent of the HPA axis. Neuropsychopharmacology 2010; 35:1241-52. [PMID: 20130533 PMCID: PMC2927867 DOI: 10.1038/npp.2009.209] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent evidence suggests that corticotropin-releasing factor (CRF) receptor (CRFR) signaling is involved in modulating binge-like ethanol consumption in C57BL/6J mice. In this report, a series of experiments were performed to further characterize the role of CRFR signaling in binge-like ethanol consumption. The role of central CRFR signaling was assessed with intracerebroventricular (i.c.v.) infusion of the nonselective CRFR antagonist, alpha-helical CRF(9-41) (0, 1, 5, 10 microg/1 microl). The contribution of central CRF type 2 receptor (CRF(2)R) signaling was assessed with i.c.v. infusion of the selective CRF(2)R agonist, urocortin (Ucn) 3 (0, 0.05, 0.1, or 0.5 microg/1 microl). The role of the hypothalamic-pituitary-adrenal (HPA) axis was assessed by pretreating mice with intraperitoneal (i.p.) injection of (1) the corticosterone synthesis inhibitor, metyrapone (0, 50, 100, 150 mg/kg) or (2) the glucocorticoid receptor antagonist, mifepristone (0, 25, 50 mg/kg), and (3) by using radioimmunoassay to determine whether binge-like ethanol intake influenced plasma corticosterone levels. Finally, we determined whether the ability of the CRF(1)R antagonist, CP-154,526 (CP; 0, 10, 15 mg/kg, i.p.), to blunt binge-like drinking required normal HPA axis signaling by comparing the effectiveness of CP in adrenalectomized (ADX) and normal mice. Results showed that i.c.v. infusion of a 1 microg dose of alpha-helical CRF(9-41) significantly attenuated binge-like ethanol consumption relative to vehicle treatment, and i.c.v. infusion of Ucn 3 dose-dependently blunted binge-like drinking. On the other hand, metyrapone nonselectively reduced both ethanol and sucrose consumption, mifepristone did not alter ethanol drinking, and binge-like drinking did not correlate with plasma corticosterone levels. Finally, i.p. injection of CP significantly attenuated binge-like ethanol intake in both ADX and normal mice. Together, these results suggest that binge-like ethanol intake in C57BL/6J mice is modulated by CRF(1)R and CRF(2)R signaling, such that blockade of CRF(1)R or activation of CRF(2)R effectively reduces excessive ethanol intake. Furthermore, normal HPA axis signaling is not necessary to achieve binge-like drinking behavior.
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Xu Z, Hou B, Zhang Y, Gao Y, Wu Y, Zhao S, Zhang C. Antidepressive behaviors induced byenriched environment might be modulated by glucocorticoid levels. Eur Neuropsychopharmacol 2009; 19:868-75. [PMID: 19664909 DOI: 10.1016/j.euroneuro.2009.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 06/03/2009] [Accepted: 07/07/2009] [Indexed: 12/21/2022]
Abstract
Exposure to enriched environment (EE) can influence expression of depression symptoms, however, the underlying mechanism has not been established, although neurogenesis was probably involved. It has been reported that EE stimulates glucocorticoids release. However, the role of corticosterone (CORT) in effects of EE is still unknown. To address these issues, we examined depression-like behaviors of the animals exposed to EE with low dose CORT supplement following bilateral adrenalectomy (ADX+CORT). Two months after housing, tail suspension test and forced swim test were used to assess depression-related behavior of mice. Serum CORT levels were measured by radio-immunoassay. Signals of DNA synthesis marker bromodeoxyuridine and immature neuronal marker doublecortin were measured by immunohistochemistry. Results showed that EE significantly decreased immobility time of the mice in both the tail suspension test and forced swim test, showing distinctive antidepressive behaviors. Exposure to EE also increased serum CORT level, and prevention of this increase with ADX+CORT eliminated the decrease of immobility time of the animals. Both the mice exposed to EE and those receiving ADX+CORT treatment showed enhanced newly born cells and immature granule neurons in the hippocampus. Taken together, our data suggest that glucocorticoids elevation is required for antidepressive behaviors of EE.
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Affiliation(s)
- Zhiwei Xu
- Beijing Institute of Radiation Medicine, State Key Laboratory of Proteomics, Beijing 100850, China
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Srinivasan M, Summerlin DJ. Modulation of the colonic epithelial cell responses and amelioration of inflammation by CD80 blockade in TNBS colitis. Clin Immunol 2009; 133:411-21. [DOI: 10.1016/j.clim.2009.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 09/02/2009] [Accepted: 09/03/2009] [Indexed: 01/01/2023]
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Chapter MC, White CM, DeRidder A, Chadwick W, Martin B, Maudsley S. Chemical modification of class II G protein-coupled receptor ligands: frontiers in the development of peptide analogs as neuroendocrine pharmacological therapies. Pharmacol Ther 2009; 125:39-54. [PMID: 19686775 DOI: 10.1016/j.pharmthera.2009.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 07/24/2009] [Indexed: 01/08/2023]
Abstract
Recent research and clinical data have begun to demonstrate the huge potential therapeutic importance of ligands that modulate the activity of the secretin-like, Class II, G protein-coupled receptors (GPCRs). Ligands that can modulate the activity of these Class II GPCRs may have important clinical roles in the treatment of a wide variety of conditions such as osteoporosis, diabetes, amyotrophic lateral sclerosis and autism spectrum disorders. While these receptors present important new therapeutic targets, the large glycoprotein nature of their cognate ligands poses many problems with respect to therapeutic peptidergic drug design. These native peptides often exhibit poor bioavailability, metabolic instability, poor receptor selectivity and resultant low potencies in vivo. Recently, increased attention has been paid to the structural modification of these peptides to enhance their therapeutic efficacy. Successful modification strategies have included d-amino acid substitutions, selective truncation, and fatty acid acylation of the peptide. Through these and other processes, these novel peptide ligand analogs can demonstrate enhanced receptor subtype selectivity, directed signal transduction pathway activation, resistance to proteolytic degradation, and improved systemic bioavailability. In the future, it is likely, through additional modification strategies such as addition of circulation-stabilizing transferrin moieties, that the therapeutic pharmacopeia of drugs targeted towards Class II secretin-like receptors may rival that of the Class I rhodopsin-like receptors that currently provide the majority of clinically used GPCR-based therapeutics. Currently, Class II-based drugs include synthesized analogs of vasoactive intestinal peptide for type 2 diabetes or parathyroid hormone for osteoporosis.
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Affiliation(s)
- Megan C Chapter
- Receptor Pharmacology Unit, Laboratory of Neuroscience, National Institute on Aging, Biomedical Research Center, 251 Bayview Blvd., Baltimore MD 21224, USA
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