1
|
Korf HW, von Gall C. Mouse Models in Circadian Rhythm and Melatonin Research. J Pineal Res 2024; 76:e12986. [PMID: 38965880 DOI: 10.1111/jpi.12986] [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: 04/22/2024] [Revised: 06/14/2024] [Accepted: 06/22/2024] [Indexed: 07/06/2024]
Abstract
This contribution reviews the role of inbred and transgenic mouse strains for deciphering the mammalian melatoninergic and circadian system. It focusses on the pineal organ as melatonin factory and two major targets of the melatoninergic system, the suprachiasmatic nuclei (SCN) and the hypophysial pars tuberalis (PT). Mammalian pinealocytes sharing molecular characteristics with true pineal and retinal photoreceptors synthesize and secrete melatonin into the blood and cerebrospinal fluid night by night. Notably, neuron-like connections exist between the deep pinealocytes and the habenular/pretectal region suggesting direct pineal-brain communication. Control of melatonin biosynthesis in rodents involves transcriptional regulation including phosphorylation of CREB and upregulation of mPer1. In the SCN, melatonin acts upon MT1 and MT2 receptors. Melatonin is not necessary to maintain the rhythm of the SCN molecular clockwork, but it has distinct effects on the synchronization of the circadian rhythm by light, facilitates re-entrainment of the circadian system to phase advances in the level of the SCN molecular clockwork by acting upon MT2 receptors and plays a stabilizing role in the circadian system as evidenced from locomotor activity recordings. While the effects in the SCN are subtle, melatonin is essential for PT functions. Via the MT1 receptor it drives the PT-intrinsic molecular clockwork and the retrograde and anterograde output pathways controlling seasonal rhythmicity. Although inbred and transgenic mice do not show seasonal reproduction, the pathways from the PT are fully intact if the animals are melatonin proficient. Thus, only melatonin-proficient strains are suited to investigate the circadian and melatoninergic systems.
Collapse
Affiliation(s)
- Horst-Werner Korf
- Institute of Anatomy I, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Charlotte von Gall
- Institute of Anatomy II, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| |
Collapse
|
2
|
Michel S, Kervezee L. One seasonal clock fits all? J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2024; 210:641-647. [PMID: 37947808 PMCID: PMC11226558 DOI: 10.1007/s00359-023-01680-4] [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: 08/31/2023] [Revised: 10/02/2023] [Accepted: 10/12/2023] [Indexed: 11/12/2023]
Abstract
Adaptation of physiology and behavior to seasonal changes in the environment are for many organisms essential for survival. Most of our knowledge about the underlying mechanisms comes from research on photoperiodic regulation of reproduction in plants, insects and mammals. However, even humans, who mostly live in environments with minimal seasonal influences, show annual rhythms in physiology (e.g., immune activity, brain function), behavior (e.g., sleep-wake cycles) and disease prevalence (e.g., infectious diseases). As seasonal variations in environmental conditions may be drastically altered due to climate change, the understanding of the mechanisms underlying seasonal adaptation of physiology and behavior becomes even more relevant. While many species have developed specific solutions for dedicated tasks of photoperiodic regulation, we find a number of common principles and mechanisms when comparing insect and mammalian systems: (1) the circadian system contributes to photoperiodic regulation; (2) similar signaling molecules (VIP and PDF) are used for transferring information from the circadian system to the neuroendocrine system controlling the photoperiodic response; (3) the hormone melatonin participates in seasonal adaptation in insects as well as mammals; and (4) changes in photoperiod affect neurotransmitter function in both animal groups. The few examples of overlap elaborated in this perspective article, as well as the discussion on relevance for humans, should be seen as encouragement to unravel the machinery of seasonal adaptation in a multitude of organisms.
Collapse
Affiliation(s)
- Stephan Michel
- Department of Cell and Chemical Biology, Leiden University Medical Center, Postzone S5-P, 2300 RC, PO Box 9600, Leiden, The Netherlands.
| | - Laura Kervezee
- Department of Cell and Chemical Biology, Leiden University Medical Center, Postzone S5-P, 2300 RC, PO Box 9600, Leiden, The Netherlands
| |
Collapse
|
3
|
Kulsoom K, Ali W, Saba Z, Hussain S, Zahra S, Irshad M, Ramzan MS. Revealing Melatonin's Mysteries: Receptors, Signaling Pathways, and Therapeutics Applications. Horm Metab Res 2024; 56:405-418. [PMID: 38081221 DOI: 10.1055/a-2226-3971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Melatonin (5-methoxy-acetyl tryptamine) is a sleep-inducing hormone, and the pineal gland produces it in response to the circadian clock of darkness. In the body, MT1 and MT2 receptors are mostly found, having an orthosteric pocket and ligand binding determinants. Melatonin acts by binding on melatonin receptors, intracellular proteins, and orphan nuclear receptors. It inhibits adenyl cyclase and activates phospholipase C, resulting in gene expression and an intracellular alteration environment. Melatonin signaling pathways are also associated with other intracellular signaling pathways, i. e., cAMP/PKA and MAPK/ERK pathways. Relative expression of different proteins depends on the coupling profile of G protein, accounting pharmacology of the melatonin receptor bias system, and mediates action in a Gi-dependent manner. It shows antioxidant, antitumor, antiproliferative, and neuroprotective activity. Different types of melatonin agonists have been synthesized for the treatment of sleeping disorders. Researchers have developed therapeutics that target melatonin signaling, which could benefit a wide range of medical conditions. This review focuses on melatonin receptors, pharmacology, and signaling cascades; it aims to provide basic mechanical aspects of the receptor's pharmacology, melatonin's functions in cancer and neurodegenerative diseases, and any treatments and drugs designed for these diseases. This will allow a basic comparison between the receptors in question, highlighting any parallels and differences that may exist and providing fundamental knowledge about these receptors to future researchers.
Collapse
Affiliation(s)
- Kulsoom Kulsoom
- Department of Biochemistry, Bahauddin Zakariya University, Multan, Pakistan
| | - Wajahat Ali
- School of Basic Medical Sciences, Xi'an Jiaotong University, Xian, China
| | - Zainab Saba
- Department of Optometry, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan, Pakistan
| | - Shabab Hussain
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, Universita degli studi di Messina, Messina, Italy
| | - Samra Zahra
- Department of Biosciences, COMSATS University Islamabad, Pakistan
| | - Maria Irshad
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Muhammad Saeed Ramzan
- Department of Pharmacology, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| |
Collapse
|
4
|
Kong X, Meerlo P, Hut RA. Melatonin Does Not Affect the Stress-Induced Phase Shifts of Peripheral Clocks in Male Mice. Endocrinology 2023; 165:bqad183. [PMID: 38128120 PMCID: PMC11083644 DOI: 10.1210/endocr/bqad183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Indexed: 12/23/2023]
Abstract
Repeated or chronic stress can change the phase of peripheral circadian rhythms. Melatonin (Mel) is thought to be a circadian clock-controlled signal that might play a role in synchronizing peripheral rhythms, in addition to its direct suppressing effects on the stress axis. In this study we test whether Mel can reduce the social-defeat stress-induced phase shifts in peripheral rhythms, either by modulating circadian phase or by modulating the stress axis. Two experiments were performed with male Mel-deficient C57BL/6J mice carrying the circadian reporter gene construct (PER2::LUC). In the first experiment, mice received night-restricted (ZT11-21) Mel in their drinking water, resulting in physiological levels of plasma Mel peaking in the early dark phase. This treatment facilitated re-entrainment of the activity rhythm to a shifted light-dark cycle, but did not prevent the stress-induced (ZT21-22) reduction of activity during stress days. Also, this treatment did not attenuate the phase-delaying effects of stress in peripheral clocks in the pituitary, lung, and kidney. In a second experiment, pituitary, lung, and kidney collected from naive mice (ZT22-23), were treated with Mel, dexamethasone (Dex), or a combination of the two. Dex application affected PER2 rhythms in the pituitary, kidney, and lung by changing period, phase, or both. Administering Mel did not influence PER2 rhythms nor did it alleviate Dex-induced delays in PER2 rhythms in those tissues. We conclude that exogenous Mel is insufficient to affect peripheral PER2 rhythms and reduce stress effects on locomotor activity and phase changes in peripheral tissues.
Collapse
Affiliation(s)
- Xiangpan Kong
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747AG, the Netherlands
- School of Medicine, Hunan Normal University, Changsha 410013, PR China
| | - Peter Meerlo
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747AG, the Netherlands
| | - Roelof A Hut
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747AG, the Netherlands
| |
Collapse
|
5
|
Starnes AN, Jones JR. Inputs and Outputs of the Mammalian Circadian Clock. BIOLOGY 2023; 12:biology12040508. [PMID: 37106709 PMCID: PMC10136320 DOI: 10.3390/biology12040508] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023]
Abstract
Circadian rhythms in mammals are coordinated by the central circadian pacemaker, the suprachiasmatic nucleus (SCN). Light and other environmental inputs change the timing of the SCN neural network oscillator, which, in turn, sends output signals that entrain daily behavioral and physiological rhythms. While much is known about the molecular, neuronal, and network properties of the SCN itself, the circuits linking the outside world to the SCN and the SCN to rhythmic outputs are understudied. In this article, we review our current understanding of the synaptic and non-synaptic inputs onto and outputs from the SCN. We propose that a more complete description of SCN connectivity is needed to better explain how rhythms in nearly all behaviors and physiological processes are generated and to determine how, mechanistically, these rhythms are disrupted by disease or lifestyle.
Collapse
|
6
|
Granado MDJ, Pinato L, Santiago J, Barbalho SM, Parmezzan JEL, Suzuki LM, Cabrini ML, Spressão DRMS, Carneiro de Camargo AL, Guissoni Campos LM. Melatonin receptors and Per1 expression in the inferior olivary nucleus of the Sapajus apella monkey. Front Neurosci 2022; 16:1072772. [PMID: 36605547 PMCID: PMC9809291 DOI: 10.3389/fnins.2022.1072772] [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: 10/17/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Melatonin is a transducer of photic environmental information and participates in the synchronization of various physiological and behavioral phenomena. Melatonin can act directly in several areas of the central nervous system through its membrane receptors coupled to G protein, called MT1 and MT2 receptors. In some structures, such as the retina, hypothalamus and pars tuberalis, the expression of both melatonin receptors shows circadian variations. Melatonin can act in the synchronization of the clock proteins rhythm in these areas. Using the immunohistochemistry technique, we detected the immunoexpression of the melatonin receptors and clock genes clock protein Per1 in the inferior olivary nucleus (ION) of the Sapajus apella monkey at specific times of the light-dark phase. The mapping performed by immunohistochemistry showed expressive immunoreactivity (IR) Per1 with predominance during daytime. Both melatonin receptors were expressed in the ION without a day/night difference. The presence of both melatonin receptors and the Per1 protein in the inferior olivary nucleus can indicate a functional role not only in physiological, as in sleep, anxiety, and circadian rhythm, but also a chronobiotic role in motor control mechanisms.
Collapse
Affiliation(s)
- Marcos Donizete Junior Granado
- Postgraduate Program in Structural and Functional Interactions in Rehabilitation, Medical School, University of Marilia (UNIMAR), Marília, Brazil
| | - Luciana Pinato
- Department of Speech, Language and Hearing Sciences, São Paulo State University (UNESP), Marília, Brazil
| | - Jeferson Santiago
- Postgraduate Program in Structural and Functional Interactions in Rehabilitation, Medical School, University of Marilia (UNIMAR), Marília, Brazil
| | - Sandra Maria Barbalho
- Postgraduate Program in Structural and Functional Interactions in Rehabilitation, Medical School, University of Marilia (UNIMAR), Marília, Brazil
| | - Jessica Ellen Lima Parmezzan
- Postgraduate Program in Structural and Functional Interactions in Rehabilitation, Medical School, University of Marilia (UNIMAR), Marília, Brazil
| | - Lenita Mayumi Suzuki
- Postgraduate Program in Structural and Functional Interactions in Rehabilitation, Medical School, University of Marilia (UNIMAR), Marília, Brazil
| | - Mayara Longui Cabrini
- Postgraduate Program in Structural and Functional Interactions in Rehabilitation, Medical School, University of Marilia (UNIMAR), Marília, Brazil
| | | | - Ana Letícia Carneiro de Camargo
- Postgraduate Program in Structural and Functional Interactions in Rehabilitation, Medical School, University of Marilia (UNIMAR), Marília, Brazil
| | - Leila Maria Guissoni Campos
- Postgraduate Program in Structural and Functional Interactions in Rehabilitation, Medical School, University of Marilia (UNIMAR), Marília, Brazil,*Correspondence: Leila Maria Guissoni Campos,
| |
Collapse
|
7
|
Pfeffer M, von Gall C, Wicht H, Korf HW. The Role of the Melatoninergic System in Circadian and Seasonal Rhythms—Insights From Different Mouse Strains. Front Physiol 2022; 13:883637. [PMID: 35492605 PMCID: PMC9039042 DOI: 10.3389/fphys.2022.883637] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 03/22/2022] [Indexed: 01/01/2023] Open
Abstract
The melatoninergic system comprises the neurohormone melatonin and its molecular targets. The major source of melatonin is the pineal organ where melatonin is rhythmically produced during darkness. In mammals, melatonin biosynthesis is controlled by the central circadian rhythm generator in the suprachiasmatic nucleus (SCN) and photoreceptors in the retina. Melatonin elicits its function principally through two specific receptors called MT1 and MT2. MT1 is highly expressed in the SCN and the hypophysial pars tuberalis (PT), an important interface for control of seasonal functions. The expression of the MT2 is more widespread. The role of the melatoninergic system in the control of seasonal functions, such as reproduction, has been known for more than 4 decades, but investigations on its impact on the circadian system under normal (entrained) conditions started 2 decades later by comparing mouse strains with a fully functional melatoninergic system with mouse strains which either produce insufficient amounts of melatonin or lack the melatonin receptors MT1 and MT2. These studies revealed that an intact melatoninergic system is not required for the generation or maintenance of rhythmic behavior under physiological entrained conditions. As shown by jet lag experiments, the melatoninergic system facilitated faster re-entrainment of locomotor activity accompanied by a more rapid adaptation of the molecular clock work in the SCN. This action depended on MT2. Further studies indicated that the endogenous melatoninergic system stabilizes the locomotor activity under entrained conditions. Notably, these effects of the endogenous melatoninergic system are subtle, suggesting that other signals such as corticosterone or temperature contribute to the synchronization of locomotor activity. Outdoor experiments lasting for a whole year indicate a seasonal plasticity of the chronotype which depends on the melatoninergic system. The comparison between mice with an intact or a compromised melatoninergic system also points toward an impact of this system on sleep, memory and metabolism.
Collapse
Affiliation(s)
- Martina Pfeffer
- Institute of Anatomy II, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
- *Correspondence: Martina Pfeffer,
| | - Charlotte von Gall
- Institute of Anatomy II, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Helmut Wicht
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin der Goethe-Universität, Frankfurt am Main, Germany
| | - Horst-Werner Korf
- Institute of Anatomy I, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| |
Collapse
|
8
|
von Gall C. The Effects of Light and the Circadian System on Rhythmic Brain Function. Int J Mol Sci 2022; 23:ijms23052778. [PMID: 35269920 PMCID: PMC8911243 DOI: 10.3390/ijms23052778] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/22/2022] [Accepted: 03/01/2022] [Indexed: 02/06/2023] Open
Abstract
Life on earth has evolved under the influence of regularly recurring changes in the environment, such as the 24 h light/dark cycle. Consequently, organisms have developed endogenous clocks, generating 24 h (circadian) rhythms that serve to anticipate these rhythmic changes. In addition to these circadian rhythms, which persist in constant conditions and can be entrained to environmental rhythms, light drives rhythmic behavior and brain function, especially in nocturnal laboratory rodents. In recent decades, research has made great advances in the elucidation of the molecular circadian clockwork and circadian light perception. This review summarizes the role of light and the circadian clock in rhythmic brain function, with a focus on the complex interaction between the different components of the mammalian circadian system. Furthermore, chronodisruption as a consequence of light at night, genetic manipulation, and neurodegenerative diseases is briefly discussed.
Collapse
Affiliation(s)
- Charlotte von Gall
- Institute of Anatomy II, Medical Faculty, Heinrich Heine University, 40225 Dusseldorf, Germany
| |
Collapse
|
9
|
Glatfelter GC, Sosa J, Hudson RL, Dubocovich ML. Methods to Assess Melatonin Receptor-Mediated Phase-Shift and Re-entrainment of Rhythmic Behaviors in Mouse Models. Methods Mol Biol 2022; 2550:391-411. [PMID: 36180708 DOI: 10.1007/978-1-0716-2593-4_39] [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] [Indexed: 06/01/2023]
Abstract
The neurohormone melatonin facilitates entrainment of biological rhythms to environmental light-dark conditions as well as phase-shifts of circadian rhythms in constant conditions via activation of the MT1 and/or MT2 receptors expressed within the suprachiasmatic nucleus of the hypothalamus. The efficacy of melatonin and related agonists to modulate biological rhythms can be assessed using two well-validated mouse models of rhythmic behaviors. These models serve as predictive measures of therapeutic efficacy for treatment of circadian phase disorders caused by internal (e.g., clock gene mutations, blindness, depression, seasonal affective disorder) or external (e.g., shift work, travel across time zones) causes in humans. Here we provide background and detailed protocols for quantitative assessment of the magnitude and efficacy of melatonin receptor ligands in mouse circadian phase-shift and re-entrainment paradigms. The utility of these models in the discovery of novel therapeutics acting on melatonin receptors will also be discussed.
Collapse
Affiliation(s)
- Grant C Glatfelter
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences University at Buffalo, Buffalo, NY, USA
- Designer Drug Research Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, USA
| | - Jennifer Sosa
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences University at Buffalo, Buffalo, NY, USA
| | - Randall L Hudson
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences University at Buffalo, Buffalo, NY, USA
| | - Margarita L Dubocovich
- Department of Pharmacology and Toxicology, Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences University at Buffalo (SUNY), Buffalo, NY, USA.
| |
Collapse
|
10
|
Leclercq B, Hicks D, Laurent V. Photoperiod integration in C3H rd1 mice. J Pineal Res 2021; 71:e12711. [PMID: 33326640 DOI: 10.1111/jpi.12711] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 11/30/2022]
Abstract
In mammals, the suprachiasmatic nuclei (SCN) constitute the main circadian clock, receiving input from the retina which allows synchronization of endogenous biological rhythms with the daily light/dark cycle. Over the year, the SCN encodes photoperiodic variations through duration of melatonin secretion, with abundant nocturnal levels in winter and lower levels in summer. Thus, light information is critical to regulate seasonal reproduction in many species and is part of the central photoperiodic integration. Since intrinsically photosensitive retinal ganglion cells (ipRGCs) are vital for circadian photoentrainment and other nonvisual functions, we studied the contribution of ipRGCs in photoperiod integration in C3H retinal degeneration 1 (rd1) mice. We assessed locomotor activity and melatonin secretion in mice exposed to short or long photoperiods. Our results showed that rd1 mice are still responsive to photoperiod variations in term of locomotor activity, melatonin secretion, and regulation of the reproductive axis. In addition, retinas of animals exposed to short photoperiod exhibit higher melanopsin labeling intensity compared with the long photoperiod condition, suggesting seasonal-dependent changes within this photoreceptive system. These results show that ipRGCs in rd1 mice can still measure photoperiod and suggest a key role of melanopsin cells in photoperiod integration and the regulation of seasonal physiology.
Collapse
Affiliation(s)
- Bastien Leclercq
- Institut des Neurosciences Cellulaires et Intégratives CNRS UPR3212, University of Strasbourg, Strasbourg, France
| | - David Hicks
- Institut des Neurosciences Cellulaires et Intégratives CNRS UPR3212, University of Strasbourg, Strasbourg, France
| | - Virginie Laurent
- Institut des Neurosciences Cellulaires et Intégratives CNRS UPR3212, University of Strasbourg, Strasbourg, France
| |
Collapse
|
11
|
Zhang C, Clough SJ, Adamah-Biassi EB, Sveinsson MH, Hutchinson AJ, Miura I, Furuse T, Wakana S, Matsumoto YK, Okanoya K, Hudson RL, Kato T, Dubocovich ML, Kasahara T. Impact of endogenous melatonin on rhythmic behaviors, reproduction, and survival revealed in melatonin-proficient C57BL/6J congenic mice. J Pineal Res 2021; 71:e12748. [PMID: 34085306 DOI: 10.1111/jpi.12748] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 12/26/2022]
Abstract
The hormone melatonin is synthesized from serotonin by two enzymatic reactions (AANAT and ASMT/HIOMT) in the pineal gland following a circadian rhythm with low levels during the day and high levels at night. The robust nightly peak of melatonin secretion is an output signal of the circadian clock to the whole organism. However, so far the regulatory roles of endogenous melatonin in mammalian biological rhythms and physiology processes are poorly understood. Here, we establish congenic mouse lines (>N10 generations) that are proficient or deficient in melatonin synthesis (AH+/+ or AH-/- mice, respectively) on the C57BL/6J genetic background by crossing melatonin-proficient MSM/Ms with C57BL/6J. AH+/+ mice displayed robust nightly peak of melatonin secretion and had significantly higher levels of pineal and plasma melatonin vs AH-/- mice. Using this mice model, we investigated the role of endogenous melatonin in regulating multiple biological rhythms, physiological processes, and rhythmic behaviors. In the melatonin-proficient (AH+/+) mice, the rate of re-entrainment of wheel-running activity was accelerated following a 6-hour phase advance of dark onset when comparted with AH-/- mice, suggesting a role of endogenous melatonin in facilitating clock adjustment. Further in the AH+/+ mice, there was a significant decrease in body weight, gonadal weight and reproductive performance, and a significant increase in daily torpor (a hypothermic and hypometabolic state lasting only hours during adverse conditions). Endogenous melatonin, however, had no effect in the modulation of the diurnal rhythm of 2-[125 I]-iodomelatonin receptor expression in the SCN, free-running wheel behavior in constant darkness, life span, spontaneous homecage behaviors, and various types of social-emotional behaviors. The findings also shed light on the role of endogenous melatonin in mice domestication and provide new insights into melatonin's action in reducing energy expenditure during a food shortage. In summary, the congenic mice model generated in this study offers a significant advantage toward understanding of the role of endogenous melatonin in regulating melatonin receptor-mediated rhythm behaviors and physiological functions.
Collapse
Affiliation(s)
- Chongyang Zhang
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York (SUNY), Buffalo, NY, USA
| | - Shannon J Clough
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York (SUNY), Buffalo, NY, USA
| | - Ekue B Adamah-Biassi
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York (SUNY), Buffalo, NY, USA
| | - Michele H Sveinsson
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York (SUNY), Buffalo, NY, USA
| | - Anthony J Hutchinson
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York (SUNY), Buffalo, NY, USA
| | - Ikuo Miura
- Technology and Development Team for Mouse Phenotype Analysis, BioResource Research Center, RIKEN, Tsukuba-shi, Ibaraki, Japan
| | - Tamio Furuse
- Technology and Development Team for Mouse Phenotype Analysis, BioResource Research Center, RIKEN, Tsukuba-shi, Ibaraki, Japan
| | - Shigeharu Wakana
- Department of Gerontology, Institute of Biomedical Research and Innovation, Kobe-shi, Hyogo, Japan
| | - Yui K Matsumoto
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Kazuo Okanoya
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Randall L Hudson
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York (SUNY), Buffalo, NY, USA
| | - Tadafumi Kato
- Laboratory for the Molecular Dynamics of Mental Disorders, Center for Brain Science, RIKEN, Wako-shi, Saitama, Japan
- Department of Psychiatry and Behavioral Science, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Margarita L Dubocovich
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York (SUNY), Buffalo, NY, USA
| | - Takaoki Kasahara
- Laboratory for the Molecular Dynamics of Mental Disorders, Center for Brain Science, RIKEN, Wako-shi, Saitama, Japan
- Career Development Program, Center for Brain Science, RIKEN, Wako-shi, Saitama, Japan
| |
Collapse
|
12
|
Moderie C, Boudreau P, Shechter A, Lesperance P, Boivin DB. Effects Of Exogenous Melatonin On Sleep And Circadian Rhythms In Women With Premenstrual Dysphoric Disorder. Sleep 2021; 44:6317701. [PMID: 34240212 DOI: 10.1093/sleep/zsab171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 07/01/2021] [Indexed: 12/18/2022] Open
Abstract
We previously found normal polysomnographic (PSG) sleep efficiency, increased slow wave sleep (SWS) and a blunted melatonin secretion in women with premenstrual dysphoric disorder (PMDD) compared to controls. Here, we investigated the effects of exogenous melatonin in five patients previously studied. They took 2 mg of slow-release melatonin 1 hour before bedtime during their luteal phase (LP) for three menstrual cycles. At baseline, patients spent every third night throughout one menstrual cycle sleeping in the laboratory. Measures included morning urinary 6-sulfatoxymelatonin (aMt6), PSG sleep, nocturnal core body temperature (CBT), visual analogue scale for mood (VAS-Mood), Prospective Record of the Impact and Severity of Menstrual Symptoms (PRISM), and ovarian hormones. Participants also underwent two 24-hour intensive physiological monitoring (during the follicular phase and LP) in time-isolation/constant conditions to determine 24-hour plasma melatonin and CBT rhythms. The same measures were repeated during their third menstrual cycle of melatonin administration. In the intervention condition compared to baseline, we found increased urinary aMt6 (p<0.001), reduced objective SOL (p=0.01), reduced SWS (p<0.001) and increased Stage 2 sleep (p<0.001). Increased urinary aMt6 was associated with reduced SWS (r=-0.51, p<0.001). Circadian parameters derived from 24-hour plasma melatonin and CBT did not differ between conditions, except for an increased melatonin mesor in the intervention condition (p=0.01). Ovarian hormones were comparable between the conditions (p≥0.28). Symptoms improved in the intervention condition, as measured by the VAS-Mood (p=0.02) and the PRISM (p<0.001). These findings support a role for disturbed melatonergic system in PMDD that can be partially corrected by exogenous melatonin.
Collapse
Affiliation(s)
- Christophe Moderie
- Centre For Study And Treatment Of Circadian Rhythms, Douglas Mental Health University Institute, Mcgill University, Montreal, Quebec, Canada.,Department Of Psychiatry, Mcgill University, Montreal, Quebec, Canada
| | - Philippe Boudreau
- Centre For Study And Treatment Of Circadian Rhythms, Douglas Mental Health University Institute, Mcgill University, Montreal, Quebec, Canada
| | - Ari Shechter
- Department Of Medicine, Columbia University, New York,NY, USA
| | - Paul Lesperance
- CHUM, Department Of Psychiatry, Université De Montréal, Quebec, Canada
| | - Diane B Boivin
- Centre For Study And Treatment Of Circadian Rhythms, Douglas Mental Health University Institute, Mcgill University, Montreal, Quebec, Canada.,Department Of Psychiatry, Mcgill University, Montreal, Quebec, Canada
| |
Collapse
|
13
|
Ruan W, Yuan X, Eltzschig HK. Circadian rhythm as a therapeutic target. Nat Rev Drug Discov 2021; 20:287-307. [PMID: 33589815 DOI: 10.1038/s41573-020-00109-w] [Citation(s) in RCA: 158] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2020] [Indexed: 12/20/2022]
Abstract
The circadian clock evolved in diverse organisms to integrate external environmental changes and internal physiology. The clock endows the host with temporal precision and robust adaptation to the surrounding environment. When circadian rhythms are perturbed or misaligned, as a result of jet lag, shiftwork or other lifestyle factors, adverse health consequences arise, and the risks of diseases such as cancer, cardiovascular diseases or metabolic disorders increase. Although the negative impact of circadian rhythm disruption is now well established, it remains underappreciated how to take advantage of biological timing, or correct it, for health benefits. In this Review, we provide an updated account of the circadian system and highlight several key disease areas with altered circadian signalling. We discuss environmental and lifestyle modifications of circadian rhythm and clock-based therapeutic strategies, including chronotherapy, in which dosing time is deliberately optimized for maximum therapeutic index, and pharmacological agents that target core clock components and proximal regulators. Promising progress in research, disease models and clinical applications should encourage a concerted effort towards a new era of circadian medicine.
Collapse
Affiliation(s)
- Wei Ruan
- Department of Anesthesiology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA.,Department of Anesthesiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Xiaoyi Yuan
- Department of Anesthesiology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Holger K Eltzschig
- Department of Anesthesiology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA.
| |
Collapse
|
14
|
Potential Role of Melatonin as an Adjuvant for Atherosclerotic Carotid Arterial Stenosis. Molecules 2021; 26:molecules26040811. [PMID: 33557283 PMCID: PMC7914857 DOI: 10.3390/molecules26040811] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/27/2021] [Accepted: 02/02/2021] [Indexed: 12/23/2022] Open
Abstract
Carotid artery stenosis (CAS) is an atherosclerotic disease characterized by a narrowing of the artery lumen and a high risk of ischemic stroke. Risk factors of atherosclerosis, including smoking, hypertension, hyperglycemia, hyperlipidemia, aging, and disrupted circadian rhythm, may potentiate atherosclerosis in the carotid artery and further reduce the arterial lumen. Ischemic stroke due to severe CAS and cerebral ischemic/reperfusion (I/R) injury after the revascularization of CAS also adversely affect clinical outcomes. Melatonin is a pluripotent agent with potent anti-inflammatory, anti-oxidative, and neuroprotective properties. Although there is a shortage of direct clinical evidence demonstrating the benefits of melatonin in CAS patients, previous studies have shown that melatonin may be beneficial for patients with CAS in terms of reducing endothelial damage, stabilizing arterial plaque, mitigating the harm from CAS-related ischemic stroke and cerebral I/R injury, and alleviating the adverse effects of the related risk factors. Additional pre-clinical and clinical are required to confirm this speculation.
Collapse
|
15
|
Bonmati-Carrion MA, Tomas-Loba A. Melatonin and Cancer: A Polyhedral Network Where the Source Matters. Antioxidants (Basel) 2021; 10:antiox10020210. [PMID: 33535472 PMCID: PMC7912767 DOI: 10.3390/antiox10020210] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/24/2021] [Accepted: 01/25/2021] [Indexed: 12/11/2022] Open
Abstract
Melatonin is one of the most phylogenetically conserved signals in biology. Although its original function was probably related to its antioxidant capacity, this indoleamine has been “adopted” by multicellular organisms as the “darkness signal” when secreted in a circadian manner and is acutely suppressed by light at night by the pineal gland. However, melatonin is also produced by other tissues, which constitute its extrapineal sources. Apart from its undisputed chronobiotic function, melatonin exerts antioxidant, immunomodulatory, pro-apoptotic, antiproliferative, and anti-angiogenic effects, with all these properties making it a powerful antitumor agent. Indeed, this activity has been demonstrated to be mediated by interfering with various cancer hallmarks, and different epidemiological studies have also linked light at night (melatonin suppression) with a higher incidence of different types of cancer. In 2007, the World Health Organization classified night shift work as a probable carcinogen due to circadian disruption, where melatonin plays a central role. Our aim is to review, from a global perspective, the role of melatonin both from pineal and extrapineal origin, as well as their possible interplay, as an intrinsic factor in the incidence, development, and progression of cancer. Particular emphasis will be placed not only on those mechanisms related to melatonin’s antioxidant nature but also on the recently described novel roles of melatonin in microbiota and epigenetic regulation.
Collapse
Affiliation(s)
- Maria-Angeles Bonmati-Carrion
- Chronobiology Laboratory, Department of Physiology, IMIB-Arrixaca, University of Murcia, 30100 Murcia, Spain
- Ciber Fragilidad y Envejecimiento Saludable, 28090 Madrid, Spain
- Correspondence: (M.-A.B.-C.); (A.T.-L.)
| | - Antonia Tomas-Loba
- Circadian Rhythm and Cancer Laboratory, Department of Physiology, IMIB-Arrixaca, University of Murcia, 30120 Murcia, Spain
- Correspondence: (M.-A.B.-C.); (A.T.-L.)
| |
Collapse
|
16
|
Tchio C, Baba K, Piccione G, Tosini G. Removal of melatonin receptor type 1 signalling induces dyslipidaemia and hormonal changes in mice subjected to environmental circadian disruption. Endocrinol Diabetes Metab 2021; 4:e00171. [PMID: 33532613 PMCID: PMC7831213 DOI: 10.1002/edm2.171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/02/2020] [Accepted: 07/05/2020] [Indexed: 11/26/2022] Open
Abstract
Background Melatonin is a hormone secreted by the pineal gland in a circadian rhythmic manner with peak synthesis at night. Melatonin signalling was suggested to play a critical role in metabolism during the circadian disruption. Methods Melatonin-proficient (C3H-f+/+ or WT) and melatonin receptor type 1 knockout (MT1 KO) male and female mice were phase-advanced (6 hours) once a week for 6 weeks. Every week, we measured weight, food intake and basal glucose levels. At the end of the experiment, we sacrificed the animals and measured the blood's plasma for lipids profile (total lipids, phospholipids, triglycerides and total cholesterol), metabolic hormones profiles (ghrelin, leptin, insulin, glucagon, glucagon-like-peptide and resistin) and the body composition. Results Environmental circadian disruption (ECD) did not produce any significant effects in C3H-f+/+, while it increased lipids profile in MT1 KO with the significant increase observed in total lipids and triglycerides. For metabolic hormones profile, ECD decreased plasma ghrelin and increased plasma insulin in MT1 KO females. Under control condition, MT1 KO females have significantly different body weight, fat mass, total lipids and total cholesterol than the control C3H-f+/+ females. Conclusion Our data show that melatonin-proficient mice are not affected by ECD. When the MT1 receptors are removed, ECD induced dyslipidaemia in males and females with females experiencing the most adverse effect. Overall, our data demonstrate that MT1 signalling is an essential modulator of lipid and metabolic homeostasis during ECD.
Collapse
Affiliation(s)
- Cynthia Tchio
- Circadian Rhythms and Sleep Disorders ProgramNeuroscience InstituteAtlantaGAUSA
- Department of Pharmacology and ToxicologyMorehouse School of MedicineNeuroscience InstituteAtlantaGAUSA
| | - Kenkichi Baba
- Circadian Rhythms and Sleep Disorders ProgramNeuroscience InstituteAtlantaGAUSA
- Department of Pharmacology and ToxicologyMorehouse School of MedicineNeuroscience InstituteAtlantaGAUSA
| | - Giuseppe Piccione
- Dipartimento di Medicine VeterinariaUniversita di MessinaMessinaItaly
| | - Gianluca Tosini
- Circadian Rhythms and Sleep Disorders ProgramNeuroscience InstituteAtlantaGAUSA
- Department of Pharmacology and ToxicologyMorehouse School of MedicineNeuroscience InstituteAtlantaGAUSA
| |
Collapse
|
17
|
Characterization of the circadian oscillator in the choroid plexus of rats. Biochem Biophys Res Commun 2020; 524:497-501. [DOI: 10.1016/j.bbrc.2020.01.125] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 01/22/2020] [Indexed: 01/01/2023]
|
18
|
Schilperoort M, van den Berg R, Bosmans LA, van Os BW, Dollé MET, Smits NAM, Guichelaar T, van Baarle D, Koemans L, Berbée JFP, Deboer T, Meijer JH, de Vries MR, Vreeken D, van Gils JM, Willems van Dijk K, van Kerkhof LWM, Lutgens E, Biermasz NR, Rensen PCN, Kooijman S. Disruption of circadian rhythm by alternating light-dark cycles aggravates atherosclerosis development in APOE*3-Leiden.CETP mice. J Pineal Res 2020; 68:e12614. [PMID: 31599473 PMCID: PMC6916424 DOI: 10.1111/jpi.12614] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/06/2019] [Accepted: 10/02/2019] [Indexed: 12/14/2022]
Abstract
Disruption of circadian rhythm by means of shift work has been associated with cardiovascular disease in humans. However, causality and underlying mechanisms have not yet been established. In this study, we exposed hyperlipidemic APOE*3-Leiden.CETP mice to either regular light-dark cycles, weekly 6 hours phase advances or delays, or weekly alternating light-dark cycles (12 hours shifts), as a well-established model for shift work. We found that mice exposed to 15 weeks of alternating light-dark cycles displayed a striking increase in atherosclerosis, with an approximately twofold increase in lesion size and severity, while mice exposed to phase advances and delays showed a milder circadian disruption and no significant effect on atherosclerosis development. We observed a higher lesion macrophage content in mice exposed to alternating light-dark cycles without obvious changes in plasma lipids, suggesting involvement of the immune system. Moreover, while no changes in the number or activation status of circulating monocytes and other immune cells were observed, we identified increased markers for inflammation, oxidative stress, and chemoattraction in the vessel wall. Altogether, this is the first study to show that circadian disruption by shifting light-dark cycles directly aggravates atherosclerosis development.
Collapse
Affiliation(s)
- Maaike Schilperoort
- Division of EndocrinologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
| | - Rosa van den Berg
- Division of EndocrinologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
| | - Laura A. Bosmans
- Department of Medical BiochemistryAmsterdam Cardiovascular SciencesAmsterdam University Medical CentreUniversity of AmsterdamAmsterdamThe Netherlands
| | - Bram W. van Os
- Department of Medical BiochemistryAmsterdam Cardiovascular SciencesAmsterdam University Medical CentreUniversity of AmsterdamAmsterdamThe Netherlands
| | - Martijn E. T. Dollé
- Centre for Health ProtectionNational Institute for Public Health and the EnvironmentBilthovenThe Netherlands
- Department of Molecular MedicineUniversity of Texas Health Science Center at San AntonioSan AntonioTXUSA
| | - Noortje A. M. Smits
- Center for Infectious Disease ControlNational Institute for Public Health and the EnvironmentBilthovenThe Netherlands
| | - Teun Guichelaar
- Center for Infectious Disease ControlNational Institute for Public Health and the EnvironmentBilthovenThe Netherlands
| | - Debbie van Baarle
- Center for Infectious Disease ControlNational Institute for Public Health and the EnvironmentBilthovenThe Netherlands
| | - Lotte Koemans
- Division of EndocrinologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
| | - Jimmy F. P. Berbée
- Division of EndocrinologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
| | - Tom Deboer
- Department of Molecular Cell BiologyLaboratory for NeurophysiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Johanna H. Meijer
- Department of Molecular Cell BiologyLaboratory for NeurophysiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Margreet R. de Vries
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
- Department of SurgeryLeiden University Medical CenterLeidenThe Netherlands
| | - Dianne Vreeken
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
- Division of NephrologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
| | - Janine M. van Gils
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
- Division of NephrologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
| | - Ko Willems van Dijk
- Division of EndocrinologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
- Department of Human GeneticsLeiden University Medical CenterLeidenThe Netherlands
| | - Linda W. M. van Kerkhof
- Centre for Health ProtectionNational Institute for Public Health and the EnvironmentBilthovenThe Netherlands
| | - Esther Lutgens
- Department of Medical BiochemistryAmsterdam Cardiovascular SciencesAmsterdam University Medical CentreUniversity of AmsterdamAmsterdamThe Netherlands
- Institute for Cardiovascular Prevention (IPEK)Ludwig‐Maximilians‐UniversitätMunichGermany
| | - Nienke R. Biermasz
- Division of EndocrinologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
| | - Patrick C. N. Rensen
- Division of EndocrinologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
| | - Sander Kooijman
- Division of EndocrinologyDepartment of MedicineLeiden University Medical CenterLeidenThe Netherlands
- Einthoven Laboratory for Experimental Vascular MedicineLeidenThe Netherlands
| |
Collapse
|
19
|
Metzger J, Wicht H, Korf HW, Pfeffer M. Seasonal Variations of Locomotor Activity Rhythms in Melatonin-Proficient and -Deficient Mice under Seminatural Outdoor Conditions. J Biol Rhythms 2019; 35:58-71. [PMID: 31625428 DOI: 10.1177/0748730419881922] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Locomotor activity patterns of laboratory mice are widely used to analyze circadian mechanisms, but most investigations have been performed under standardized laboratory conditions. Outdoors, animals are exposed to daily changes in photoperiod and other abiotic cues that might influence their circadian system. To investigate how the locomotor activity patterns under outdoor conditions compare to controlled laboratory conditions, we placed 2 laboratory mouse strains (melatonin-deficient C57Bl and melatonin-proficient C3H) in the garden of the Dr. Senckenbergische Anatomie in Frankfurt am Main. The mice were kept singly in cages equipped with an infrared locomotion detector, a hiding box, nesting material, and with food and water ad libitum. The locomotor activity of each mouse was recorded for 1 year, together with data on ambient temperature, light, and humidity. Chronotype, chronotype stability, total daily activity, duration of the activity period, and daily diurnality indices were determined from the actograms. C3H mice showed clear seasonal differences in the chronotype, its stability, the total daily activity, and the duration of the activity period. These pronounced seasonal differences were not observed in the C57Bl. In both strains, the onset of the main activity period was mainly determined by the evening dusk, whereas the offset was influenced by the ambient temperature. The actograms did not reveal infra-, ultradian, or lunar rhythms or a weekday/weekend pattern. Under outdoor conditions, the 2 strains retained their nocturnal locomotor identity as observed in the laboratory. Our results indicate that the chronotype displays a seasonal plasticity that may depend on the melatoninergic system. Photoperiod and ambient temperature are the most potent abiotic entraining cues. The timing of the evening dusk mainly affects the onset of the activity period; the ambient temperature during this period influences the latter's duration. Humidity, overall light intensities, and human activities do not affect the locomotor behavior.
Collapse
Affiliation(s)
- Joshua Metzger
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
| | - Helmut Wicht
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
| | - Horst-Werner Korf
- Institut für Anatomie I, Fachbereich Medizin, Heinrich Heine Universität, Düsseldorf, Germany
| | - Martina Pfeffer
- Institut für Anatomie II, Fachbereich Medizin, Heinrich Heine Universität, Düsseldorf, Germany
| |
Collapse
|
20
|
Abstract
Despite considerable advances in the past few years, obesity and type 2 diabetes mellitus (T2DM) remain two major challenges for public health systems globally. In the past 9 years, genome-wide association studies (GWAS) have established a major role for genetic variation within the MTNR1B locus in regulating fasting plasma levels of glucose and in affecting the risk of T2DM. This discovery generated a major interest in the melatonergic system, in particular the melatonin MT2 receptor (which is encoded by MTNR1B). In this Review, we discuss the effect of melatonin and its receptors on glucose homeostasis, obesity and T2DM. Preclinical and clinical post-GWAS evidence of frequent and rare variants of the MTNR1B locus confirmed its importance in regulating glucose homeostasis and T2DM risk with minor effects on obesity. However, these studies did not solve the question of whether melatonin is beneficial or detrimental, an issue that will be discussed in the context of the peculiarities of the melatonergic system. Melatonin receptors might have therapeutic potential as they belong to the highly druggable G protein-coupled receptor superfamily. Clarifying the precise role of melatonin and its receptors on glucose homeostasis is urgent, as melatonin is widely used for other indications, either as a prescribed medication or as a supplement without medical prescription, in many countries in Europe and in the USA.
Collapse
Affiliation(s)
- Angeliki Karamitri
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France
| | - Ralf Jockers
- Inserm, U1016, Institut Cochin, Paris, France.
- CNRS UMR 8104, Paris, France.
- Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France.
| |
Collapse
|
21
|
Silva ACPE, Santos MJD, Koike BDV, Moreira MSA, Gitai DLG, de Miranda Coelho JAP, de Andrade TG. Melatonin receptor 1B -1193T>C polymorphism is associated with diurnal preference and sleep habits. Sleep Med 2018; 53:106-114. [PMID: 30508778 DOI: 10.1016/j.sleep.2018.09.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/26/2018] [Accepted: 09/03/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND Melatonin modulates the master circadian clock through the activation of G-protein-coupled receptors MT1 and MT2. It is presumed, therefore, that genetic variations in melatonin receptors can affect both sleep and circadian phase. We investigated whether the -1193T > C (rs4753426) polymorphism in the promoter of MT2 receptor gene (MTNR1B) is associated with diurnal preference and sleep habits. This polymorphism was previously associated with sunshine duration, suggesting a role in circadian entrainment. METHODS A total of 814 subjects who completed the Morningness-Eveningness and the Munich Chronotype questionnaires were genotyped for the selected polymorphism. Linear and multinomial regression were performed to test the interaction between gene variants and diurnal preference/sleep habits. RESULTS The -1193C variant was associated with the extreme morningness phenotype in a codominant model (C/C vs. T/T), recessive model (C/C + C/T vs. T/T) and alleles (C vs. T). A negative correlation was found between -1193C alleles and social jetlag scores. The frequency of -1193T allele was higher in the group that stay in bed more than 8 h/night compared to the group that stay in bed less than 8 h/night on weekends. CONCLUSION To the best of our knowledge, these data provide the first insights into the role of MTNR1B gene in the regulation of sleep, biological rhythms, and entrainment in humans.
Collapse
Affiliation(s)
| | - Maria José Dos Santos
- Laboratory of Molecular Chronobiology, Federal University of Alagoas (UFAL), Alagoas, Brazil
| | - Bruna Del Vechio Koike
- Laboratory of Molecular Chronobiology, Federal University of Alagoas (UFAL), Alagoas, Brazil
| | | | - Daniel Leite Goes Gitai
- Laboratory of Cellular and Molecular Biology, Federal University of Alagoas (UFAL), Alagoas, Brazil
| | | | - Tiago Gomes de Andrade
- Laboratory of Molecular Chronobiology, Federal University of Alagoas (UFAL), Alagoas, Brazil; Faculty of Medicine, Federal University of Alagoas (UFAL), Alagoas, Brazil.
| |
Collapse
|
22
|
Cecon E, Oishi A, Jockers R. Melatonin receptors: molecular pharmacology and signalling in the context of system bias. Br J Pharmacol 2018; 175:3263-3280. [PMID: 28707298 PMCID: PMC6057902 DOI: 10.1111/bph.13950] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 07/05/2017] [Accepted: 07/10/2017] [Indexed: 12/15/2022] Open
Abstract
Melatonin, N-acetyl-5-methoxytryptamine, an evolutionally old molecule, is produced by the pineal gland in vertebrates, and it binds with high affinity to melatonin receptors, which are members of the GPCR family. Among the multiple effects attributed to melatonin, we will focus here on those that are dependent on the activation of the two mammalian MT1 and MT2 melatonin receptors. We briefly summarize the latest developments on synthetic melatonin receptor ligands, including multi-target-directed ligands, and the characterization of signalling-biased ligands. We discuss signalling pathways activated by melatonin receptors that appear to be highly cell- and tissue-dependent, emphasizing the impact of system bias on the functional outcome. Different proteins have been demonstrated to interact with melatonin receptors, and thus, we postulate that part of this system bias has its molecular basis in differences of the expression of receptor-associated proteins including heterodimerization partners. Finally, bias at the level of the receptor, by the expression of genetic receptor variants, will be discussed to show how a modified receptor function can have an effect on the risk for common diseases like type 2 diabetes in humans. LINKED ARTICLES: This article is part of a themed section on Recent Developments in Research of Melatonin and its Potential Therapeutic Applications. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.16/issuetoc.
Collapse
Affiliation(s)
- Erika Cecon
- Institut CochinInserm, U1016ParisFrance
- CNRS UMR 8104ParisFrance
- Univ. Paris Descartes, Sorbonne Paris CitéParisFrance
| | - Atsuro Oishi
- Institut CochinInserm, U1016ParisFrance
- CNRS UMR 8104ParisFrance
- Univ. Paris Descartes, Sorbonne Paris CitéParisFrance
| | - Ralf Jockers
- Institut CochinInserm, U1016ParisFrance
- CNRS UMR 8104ParisFrance
- Univ. Paris Descartes, Sorbonne Paris CitéParisFrance
| |
Collapse
|
23
|
Dmitrzak-Weglarz M, Reszka E. Pathophysiology of Depression: Molecular Regulation of Melatonin Homeostasis - Current Status. Neuropsychobiology 2018; 76:117-129. [PMID: 29898451 DOI: 10.1159/000489470] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/19/2018] [Indexed: 12/29/2022]
Abstract
Circadian rhythm alterations resulting in disturbed sleep and disturbed melatonin secretion are flagship features of depression. Melatonin, known as a hormone of darkness, is secreted by the pineal gland located near to the center of the brain between the two hemispheres. Melatonin has an antidepressant effect by maintaining the body's circadian rhythm, by regulating the pattern of expression of the clock genes in the suprachiasmatic nucleus (SCN) and modifying the key genes of serotoninergic neurotransmission that are linked with a depressive mood. Melatonin is produced via the metabolism of serotonin in two steps which are catalyzed by serotonin N-acetyltransferase (SNAT) and acetylserotonin-O-methyltransferase (ASMT). Serotonin, SNAT, and ASMT are key melatonin level regulation factors. Melatonin acts mainly on the MT1 and MT2 receptors, which are present in the SCN, to regulate physiological and neuroendocrine functions including circadian entrainment, referred to as a chronobiotic effect. Although melatonin has been known about and refereed to for almost 50 years, the relationship between melatonin and depression is still not clear. In this review, we summarize current knowledge about the genetic and epigenetic regulation of enzymes involved in melatonin synthesis and metabolism as potential features of depression pathophysiology and treatment. Confirmation that melatonin metabolism in peripheral blood partially reflects a disorder in the brain could be a breakthrough in the standardization of measurements of melatonin level for the development of treatment standards, finding new therapeutic targets, and elaborating simple noninvasive clinical tests.
Collapse
Affiliation(s)
- Monika Dmitrzak-Weglarz
- Department of Psychiatric Genetics, Department of Psychiatry, Poznan University of Medical Sciences, Poznan, Poland
| | - Edyta Reszka
- Department of Molecular Genetics and Epigenetics, Nofer Institute of Occupational Medicine, Lodz, Poland
| |
Collapse
|
24
|
Pfeffer M, Zimmermann Z, Gispert S, Auburger G, Korf HW, von Gall C. Impaired Photic Entrainment of Spontaneous Locomotor Activity in Mice Overexpressing Human Mutant α-Synuclein. Int J Mol Sci 2018; 19:E1651. [PMID: 29865270 PMCID: PMC6032049 DOI: 10.3390/ijms19061651] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 01/17/2023] Open
Abstract
Parkinson's disease (PD) is characterized by distinct motor and non-motor symptoms. Sleep disorders are the most frequent and challenging non-motor symptoms in PD patients, and there is growing evidence that they are a consequence of disruptions within the circadian system. PD is characterized by a progressive degeneration of the dorsal vagal nucleus and midbrain dopaminergic neurons together with an imbalance of many other neurotransmitters. Mutations in α-synuclein (SNCA), a protein modulating SNARE complex-dependent neurotransmission, trigger dominantly inherited PD variants and sporadic cases of PD. The A53T SNCA missense mutation is associated with an autosomal dominant early-onset familial PD. To test whether this missense mutation affects the circadian system, we analyzed the spontaneous locomotor behavior of non-transgenic wildtype mice and transgenic mice overexpressing mutant human A53T α-synuclein (A53T). The mice were subjected to entrained- and free-running conditions as well as to experimental jet lag. Furthermore, the vesicular glutamate transporter 2 (VGLUT2) in the suprachiasmatic nucleus (SCN) was analyzed by immunohistochemistry. Free-running circadian rhythm and, thus, circadian rhythm generation, were not affected in A53T mice. A53T mice entrained to the light⁻dark cycle, however, with an advanced phase angle of 2.65 ± 0.5 h before lights off. Moreover, re-entrainment after experimental jet lag was impaired in A53T mice. Finally, VGLUT2 immunoreaction was reduced in the SCN of A53T mice. These data suggest an impaired light entrainment of the circadian system in A53T mice.
Collapse
Affiliation(s)
- Martina Pfeffer
- Institut für Anatomie II, Fachbereich Medizin, Heinrich Heine Universität, Universitätsstr. 1, D-40225 Düsseldorf, Germany.
| | - Zuzana Zimmermann
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| | - Suzana Gispert
- Experimental Neurology, Department of Neurology, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| | - Georg Auburger
- Experimental Neurology, Department of Neurology, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| | - Horst-Werner Korf
- Institut für Anatomie I, Fachbereich Medizin, Heinrich Heine Universität, Universitätsstr. 1, D-40225 Düsseldorf, Germany.
| | - Charlotte von Gall
- Institut für Anatomie II, Fachbereich Medizin, Heinrich Heine Universität, Universitätsstr. 1, D-40225 Düsseldorf, Germany.
| |
Collapse
|
25
|
Pfeffer M, Korf HW, Wicht H. Synchronizing effects of melatonin on diurnal and circadian rhythms. Gen Comp Endocrinol 2018; 258:215-221. [PMID: 28533170 DOI: 10.1016/j.ygcen.2017.05.013] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 04/27/2017] [Accepted: 05/16/2017] [Indexed: 01/02/2023]
Abstract
In mammals, the rhythmic secretion of melatonin from the pineal gland is driven by the circadian clock in the suprachiasmatic nucleus (SCN) of the hypothalamus. The robust nightly peak of melatonin secretion is an output signal of the circadian clock and is supposed to deliver the circadian message to the whole of the organism. Since the circadian system regulates many behavioral and physiological processes, its disruption by external (shift-work, jet-lag) or internal desynchronization (blindness, aging) causes many different health problems. Externally applied melatonin is used in humans as a chronobiotic drug to treat desynchronization and circadian disorders, and the success of these treatments does, at first glance, underline the supposed pivotal role of melatonin in the synchronization of the circadian system. On the other hand, pinealectomy in experimental animals and humans does not abolish their rhythms of rest and activity. Furthermore, mice with deficient melatoninergic systems neither display overt defects in their rhythmic behavior nor do they show obvious signs of disease susceptibility, let alone premature mortality. During the last years, our laboratory has investigated several mouse stains with intact or compromised internal melatonin signaling systems in order to better understand the physiological role of the melatoninergic system. These and other investigations which will be reviewed in the present contribution confirm the synchronizing effect of endogenous melatonin and the melatoninergic system. However, these effects are subtle. Thus melatonin does not appear as the master of internal synchronization, but as one component in a cocktail of synchronizing agents.
Collapse
Affiliation(s)
- Martina Pfeffer
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany; Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| | - Horst-Werner Korf
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany; Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| | - Helmut Wicht
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| |
Collapse
|
26
|
Sulkava S, Ollila HM, Alasaari J, Puttonen S, Härmä M, Viitasalo K, Lahtinen A, Lindström J, Toivola A, Sulkava R, Kivimäki M, Vahtera J, Partonen T, Silander K, Porkka-Heiskanen T, Paunio T. Common Genetic Variation Near Melatonin Receptor 1A Gene Linked to Job-Related Exhaustion in Shift Workers. Sleep 2017; 40:2980926. [PMID: 28364478 PMCID: PMC5806557 DOI: 10.1093/sleep/zsw011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Study Objectives Tolerance to shift work varies; only some shift workers suffer from disturbed sleep, fatigue, and job-related exhaustion. Our aim was to explore molecular genetic risk factors for intolerance to shift work. Methods We assessed intolerance to shift work with job-related exhaustion symptoms in shift workers using the emotional exhaustion subscale of the Maslach Burnout Inventory-General Survey, and carried out a genome-wide association study (GWAS) using Illumina's Human610-Quad BeadChip (n = 176). The most significant findings were further studied in three groups of Finnish shift workers (n = 577). We assessed methylation in blood cells with the Illumina HumanMethylation450K BeadChip, and examined gene expression levels in the publicly available eGWAS Mayo data. Results The second strongest signal identified in the GWAS (p = 2.3 × 10E-6) was replicated in two of the replication studies with p < .05 (p = 2.0 × 10E-4 when combining the replication studies) and indicated an association of job-related exhaustion in shift workers with rs12506228, located downstream of the melatonin receptor 1A gene (MTNR1A). The risk allele was also associated with reduced in silico gene expression levels of MTNR1A in brain tissue and suggestively associated with changes in DNA methylation in the 5' regulatory region of MTNR1A. Conclusions These findings suggest that a variant near MTNR1A may be associated with job-related exhaustion in shift workers. The risk variant may exert its effect via epigenetic mechanisms, potentially leading to reduced melatonin signaling in the brain. These results could indicate a link between melatonin signaling, a key circadian regulatory mechanism, and tolerance to shift work.
Collapse
Affiliation(s)
- Sonja Sulkava
- Department of Health, Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland.,Department of Psychiatry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Hanna M Ollila
- Department of Health, Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland.,Department of Psychiatry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland.,The Stanford Center for Sleep Sciences, Stanford University, Palo Alto, CA
| | - Jukka Alasaari
- Department of Health, Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland.,Department of Psychiatry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Sampsa Puttonen
- Modern Work and Leadership, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Mikko Härmä
- Modern Work and Leadership, Finnish Institute of Occupational Health, Helsinki, Finland
| | | | - Alexandra Lahtinen
- Department of Health, Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland.,Department of Psychiatry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Jaana Lindström
- Department of Health, Chronic Disease Prevention Unit, National Institute for Health and Welfare, Helsinki, Finland
| | - Auli Toivola
- Department of Health, Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland
| | - Raimo Sulkava
- Unit of Geriatrics, University of Eastern Finland, Kuopio, Finland
| | - Mika Kivimäki
- Modern Work and Leadership, Finnish Institute of Occupational Health, Helsinki, Finland.,Department of Epidemiology and Public Health, University College London, London, UK
| | - Jussi Vahtera
- Department of Public Health, University of Turku and Turku University Hospital, Turku, Finland
| | - Timo Partonen
- Department of Health, Mental Health Unit, National Institute for Health and Welfare, Helsinki, Finland
| | - Kaisa Silander
- Department of Health, Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland
| | | | - Tiina Paunio
- Department of Health, Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland.,Department of Psychiatry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| |
Collapse
|
27
|
Ubaldo-Reyes L, Buijs R, Escobar C, Ángeles-Castellanos M. Scheduled meal accelerates entrainment to a 6-h phase advance by shifting central and peripheral oscillations in rats. Eur J Neurosci 2017; 46:1875-1886. [DOI: 10.1111/ejn.13633] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/24/2017] [Accepted: 06/20/2017] [Indexed: 12/11/2022]
Affiliation(s)
- L.M. Ubaldo-Reyes
- Departamento de Anatomía; Facultad de Medicina; Universidad Nacional Autónoma de México; México DF 04510 Mexico
| | - R.M. Buijs
- Laboratorio Mecanismos de Integración Hipotalámica; Instituto de Investigaciones Biomédicas; Universidad Nacional Autónoma de México; México DF Mexico
| | - C. Escobar
- Departamento de Anatomía; Facultad de Medicina; Universidad Nacional Autónoma de México; México DF 04510 Mexico
| | - M. Ángeles-Castellanos
- Departamento de Anatomía; Facultad de Medicina; Universidad Nacional Autónoma de México; México DF 04510 Mexico
| |
Collapse
|
28
|
Man GCW, Zhang T, Chen X, Wang J, Wu F, Liu Y, Wang CC, Cheong Y, Li TC. The regulations and role of circadian clock and melatonin in uterine receptivity and pregnancy-An immunological perspective. Am J Reprod Immunol 2017; 78. [DOI: 10.1111/aji.12715] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/04/2017] [Indexed: 12/22/2022] Open
Affiliation(s)
- Gene Chi Wai Man
- Department of Orthopaedics and Traumatology; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
- Department of Obstetrics and Gynaecology; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
| | - Tao Zhang
- Shenzhen Key Laboratory of Reproductive Immunology for Peri-Implantation; Fertility Center; Shenzhen Zhongshan Urology Hospital; Shenzhen China
| | - Xiaoyan Chen
- Department of Obstetrics and Gynaecology; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
| | - Jianzhang Wang
- Department of Obstetrics and Gynaecology; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
| | - Fangrong Wu
- Department of Obstetrics and Gynaecology; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
| | - Yingyu Liu
- Department of Obstetrics and Gynaecology; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
| | - Chi Chiu Wang
- Department of Obstetrics and Gynaecology; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
- Li Ka Shing Institute of Health Sciences; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
- School of Biomedical Sciences; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
| | - Ying Cheong
- Human Development and Health; Princess Anne Hospital; University of Southampton Faculty of Medicine; Southampton UK
| | - Tin Chiu Li
- Department of Obstetrics and Gynaecology; Faculty of Medicine; The Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong SAR
| |
Collapse
|
29
|
Rocha AKADA, de Lima E, Amaral F, Peres R, Cipolla-Neto J, Amado D. Altered MT1 and MT2 melatonin receptors expression in the hippocampus of pilocarpine-induced epileptic rats. Epilepsy Behav 2017; 71:23-34. [PMID: 28460319 DOI: 10.1016/j.yebeh.2017.01.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Revised: 01/20/2017] [Accepted: 01/20/2017] [Indexed: 12/11/2022]
Abstract
Clinical and experimental findings show that melatonin may be used as an adjuvant to the treatment of epilepsy-related complications by alleviates sleep disturbances, circadian alterations and attenuates seizures alone or in combination with AEDs. In addition, it has been observed that there is a circadian component on seizures, which cause changes in circadian system and in melatonin production. Nevertheless, the dynamic changes of the melatoninergic system, especially with regard to its membrane receptors (MT1 and MT2) in the natural course of TLE remain largely unknown. The aim of this study was to evaluate the 24-hour profile of MT1 and MT2 mRNA and protein expression in the hippocampus of rats submitted to the pilocarpine-induced epilepsy model analyzing the influence of the circadian rhythm in the expression pattern during the acute, silent, and chronic phases. Melatonin receptor MT1 and MT2 mRNA expression levels were increased in the hippocampus of rats few hours after SE, with MT1 returning to normal levels and MT2 reducing during the silent phase. During the chronic phase, mRNA expression levels of both receptors return to levels close to control, however, presenting a different daily profile, showing that there is a circadian change during the chronic phase. Also, during the acute and silent phase it was possible to verify MT1 label only in CA2 hippocampal region with an increased expression only in the dark period of the acute phase. The MT2 receptor was present in all hippocampal regions, however, it was reduced in the acute phase and it was found in astrocytes. In chronic animals, there is a reduction in the presence of both receptors especially in regions where there is a typical damage derived from epilepsy. Therefore, we conclude that SE induced by pilocarpine is able to change melatonin receptor MT1 and MT2 protein and mRNA expression levels in the hippocampus of rats few hours after SE as well as in silent and chronic phases.
Collapse
Affiliation(s)
| | - Eliangela de Lima
- Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil; Department of Physiology and Biophysics, Institute of Biomedical Science, Universidade de São Paulo, São Paulo, SP, Brazil; Department of Physiology, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil
| | - Fernanda Amaral
- Department of Physiology and Biophysics, Institute of Biomedical Science, Universidade de São Paulo, São Paulo, SP, Brazil; Departament of Physiology, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil
| | - Rafael Peres
- Department of Physiology and Biophysics, Institute of Biomedical Science, Universidade de São Paulo, São Paulo, SP, Brazil
| | - José Cipolla-Neto
- Department of Physiology and Biophysics, Institute of Biomedical Science, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Débora Amado
- Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil
| |
Collapse
|
30
|
Pfeffer M, Korf HW, Wicht H. The Role of the Melatoninergic System in Light-Entrained Behavior of Mice. Int J Mol Sci 2017; 18:ijms18030530. [PMID: 28257037 PMCID: PMC5372546 DOI: 10.3390/ijms18030530] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 02/16/2017] [Accepted: 02/26/2017] [Indexed: 01/20/2023] Open
Abstract
The role of endogenous melatonin for the control of the circadian system under entrained conditions and for the determination of the chronotype is still poorly understood. Mice with deletions in the melatoninergic system (melatonin deficiency or the lack of melatonin receptors, respectively) do not display any obvious defects in either their spontaneous (circadian) or entrained (diurnal) rhythmic behavior. However, there are effects that can be detected by analyzing the periodicity of the locomotor behaviors in some detail. We found that melatonin-deficient mice (C57Bl), as well as melatonin-proficient C3H mice that lack the melatonin receptors (MT) 1 and 2 (C3H MT1,2 KO), reproduce their diurnal locomotor rhythms with significantly less accuracy than mice with an intact melatoninergic system. However, their respective chronotypes remained unaltered. These results show that one function of the endogenous melatoninergic system might be to stabilize internal rhythms under conditions of a steady entrainment, while it has no effects on the chronotype.
Collapse
MESH Headings
- Animals
- Behavior, Animal
- Circadian Rhythm
- Light
- Male
- Melatonin/biosynthesis
- Melatonin/deficiency
- Mice
- Mice, Knockout
- Motor Activity
- Receptor, Melatonin, MT1/deficiency
- Receptor, Melatonin, MT1/genetics
- Receptor, Melatonin, MT1/metabolism
- Receptor, Melatonin, MT2/deficiency
- Receptor, Melatonin, MT2/genetics
- Receptor, Melatonin, MT2/metabolism
Collapse
Affiliation(s)
- Martina Pfeffer
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
- Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| | - Horst-Werner Korf
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
- Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| | - Helmut Wicht
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| |
Collapse
|
31
|
Pinato L, Ramos D, Hataka A, Rossignoli PS, Granado MD, Mazzetto MC, Campos LMG. Day/night expression of MT 1 and MT 2 receptors in hypothalamic nuclei of the primate Sapajus apella. J Chem Neuroanat 2017; 81:10-17. [PMID: 28159659 DOI: 10.1016/j.jchemneu.2017.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 01/29/2017] [Accepted: 01/30/2017] [Indexed: 12/19/2022]
Abstract
Melatonin is involved in the temporal organization of several physiological and behavioral events, controlled by hypothalamic nuclei, like sleep, feeding, reproduction and metabolic modulation and acts through two types of high-affinity G protein-coupled membrane receptors: MT1 and MT2. This study aimed to investigate the expression of MT1 and MT2 receptors proteins in four hypothalamic nuclei, i.e., SCN, supraoptic (SON), paraventricular (PVN) and anteroventral periventricular nuclei (AVPV), of the diurnal primate Sapajus apella using immunohistochemistry. Since these areas are involved in the expression of biological rhythms, they are candidates to have variations in their neurochemistry, so the MT1 and MT2 expression has been analyzed at a point in light and another in the dark phase. Both receptors were found to have day/night differences in the four hypothalamic nuclei with an apparent inverse expression in the SCN compared with the other areas. These differences could be related to the idea that the individual should be prepared to respond by different ways to melatonin signal within the several processes and can contribute to the efficacy of melatonin ligands or melatonin in therapies.
Collapse
Affiliation(s)
| | - Dayane Ramos
- University of Marilia (UNIMAR), Medical School, Marilia, SP, Brazil
| | | | | | | | | | - Leila M G Campos
- São Paulo State University (UNESP), Marilia, SP, Brazil; University of Marilia (UNIMAR), Medical School, Marilia, SP, Brazil.
| |
Collapse
|
32
|
Pfeffer M, Gispert S, Auburger G, Wicht H, Korf HW. Impact of Ataxin-2 knock out on circadian locomotor behavior and PER immunoreaction in the SCN of mice. Chronobiol Int 2016; 34:129-137. [PMID: 27791392 DOI: 10.1080/07420528.2016.1245666] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In Drosophila melanogaster, Ataxin-2 is a crucial activator of Period and is involved in the control of circadian rhythms. However, in mammals the function of Ataxin-2 is unknown despite its involvement in the inherited neurogenerative disease Spinocerebellar Ataxia type 2 in humans. Therefore, we analyzed locomotor behavior of Atxn2-deficient mice and their WT littermates under entrained- and free-running conditions as well as after experimental jet lag. Furthermore, we compared the PER1 and PER2 immunoreaction (IR) in the SCN. Atxn2-/- mice showed an unstable rhythmicity of locomotor activity, but the level of PER1 and PER2 IR in the SCN did not differ between genotypes.
Collapse
Affiliation(s)
- Martina Pfeffer
- a Dr. Senckenbergische Anatomie II, Fachbereich Medizin , Goethe-Universität Frankfurt , Frankfurt am Main , Germany.,b Dr. Senckenbergisches Chronomedizinisches Institut , Goethe-Universität Frankfurt , Frankfurt am Main , Germany
| | - Suzana Gispert
- c Experimental Neurology, Department of Neurology , Goethe-Universität Frankfurt , Frankfurt am Main , Germany
| | - Georg Auburger
- c Experimental Neurology, Department of Neurology , Goethe-Universität Frankfurt , Frankfurt am Main , Germany
| | - Helmut Wicht
- a Dr. Senckenbergische Anatomie II, Fachbereich Medizin , Goethe-Universität Frankfurt , Frankfurt am Main , Germany
| | - Horst-Werner Korf
- a Dr. Senckenbergische Anatomie II, Fachbereich Medizin , Goethe-Universität Frankfurt , Frankfurt am Main , Germany.,b Dr. Senckenbergisches Chronomedizinisches Institut , Goethe-Universität Frankfurt , Frankfurt am Main , Germany
| |
Collapse
|
33
|
Jockers R, Delagrange P, Dubocovich ML, Markus RP, Renault N, Tosini G, Cecon E, Zlotos DP. Update on melatonin receptors: IUPHAR Review 20. Br J Pharmacol 2016; 173:2702-25. [PMID: 27314810 DOI: 10.1111/bph.13536] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/15/2016] [Accepted: 05/19/2016] [Indexed: 02/06/2023] Open
Abstract
Melatonin receptors are seven transmembrane-spanning proteins belonging to the GPCR superfamily. In mammals, two melatonin receptor subtypes exist - MT1 and MT2 - encoded by the MTNR1A and MTNR1B genes respectively. The current review provides an update on melatonin receptors by the corresponding subcommittee of the International Union of Basic and Clinical Pharmacology. We will highlight recent developments of melatonin receptor ligands, including radioligands, and give an update on the latest phenotyping results of melatonin receptor knockout mice. The current status and perspectives of the structure of melatonin receptor will be summarized. The physiological importance of melatonin receptor dimers and biologically important and type 2 diabetes-associated genetic variants of melatonin receptors will be discussed. The role of melatonin receptors in physiology and disease will be further exemplified by their functions in the immune system and the CNS. Finally, antioxidant and free radical scavenger properties of melatonin and its relation to melatonin receptors will be critically addressed.
Collapse
Affiliation(s)
- Ralf Jockers
- Inserm, U1016, Institut Cochin, Paris, France.,CNRS UMR 8104, Paris, France.,University Paris Descartes, Paris, France
| | | | - Margarita L Dubocovich
- Department Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Science, University at Buffalo (SUNY), Buffalo, USA
| | - Regina P Markus
- Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | | | - Gianluca Tosini
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Erika Cecon
- Inserm, U1016, Institut Cochin, Paris, France.,CNRS UMR 8104, Paris, France.,University Paris Descartes, Paris, France
| | - Darius P Zlotos
- Department of Pharmaceutical Chemistry, The German University in Cairo, New Cairo City, Cairo, Egypt
| |
Collapse
|
34
|
Melatonin Signal Transduction Pathways Require E-Box-Mediated Transcription of Per1 and Per2 to Reset the SCN Clock at Dusk. PLoS One 2016; 11:e0157824. [PMID: 27362940 PMCID: PMC4928778 DOI: 10.1371/journal.pone.0157824] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 06/06/2016] [Indexed: 12/12/2022] Open
Abstract
Melatonin is released from the pineal gland into the circulatory system at night in the absence of light, acting as “hormone of darkness” to the brain and body. Melatonin also can regulate circadian phasing of the suprachiasmatic nucleus (SCN). During the day-to-night transition, melatonin exposure advances intrinsic SCN neural activity rhythms via the melatonin type-2 (MT2) receptor and downstream activation of protein kinase C (PKC). The effects of melatonin on SCN phasing have not been linked to daily changes in the expression of core genes that constitute the molecular framework of the circadian clock. Using real-time RT-PCR, we found that melatonin induces an increase in the expression of two clock genes, Period 1 (Per1) and Period 2 (Per2). This effect occurs at CT 10, when melatonin advances SCN phase, but not at CT 6, when it does not. Using anti-sense oligodeoxynucleotides (α ODNs) to Per 1 and Per 2, as well as to E-box enhancer sequences in the promoters of these genes, we show that their specific induction is necessary for the phase-altering effects of melatonin on SCN neural activity rhythms in the rat. These effects of melatonin on Per1 and Per2 were mediated by PKC. This is unlike day-active non-photic signals that reset the SCN clock by non-PCK signal transduction mechanisms and by decreasing Per1 expression. Rather, this finding extends roles for Per1 and Per2, which are critical to photic phase-resetting, to a nonphotic zeitgeber, melatonin, and suggest that the regulation of these clock gene transcripts is required for clock resetting by diverse regulatory cues.
Collapse
|
35
|
Homola M, Pfeffer M, Robson SC, Fischer C, Zimmermann H, Korf HW. Melatonin receptor deficiency decreases and temporally shifts ecto-5'-nucleotidase mRNA levels in mouse prosencephalon. Cell Tissue Res 2016; 365:147-56. [PMID: 26917036 DOI: 10.1007/s00441-016-2378-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 02/12/2016] [Indexed: 11/29/2022]
Abstract
Ecto-5'-nucleotidase (eN) is the major extracellular adenosine-producing ecto-enzyme in mouse brain. Via the production of adenosine, eN participates in many physiological and pathological processes, such as wakefulness, inflammation, nociception and neuroprotection. The mechanisms regulating the expression of eN are therefore of considerable neurobiological and clinical interest. Having previously described a modulatory effect of melatonin in the regulation of eN mRNA levels, we decided to analyze the melatonin receptor subtype involved in the regulation of eN mRNA levels by comparing eN mRNA patterns in melatonin-proficient transgenic mice lacking either the melatonin receptor subtype 1 (MT1 KO) or both melatonin receptor subtypes (MT1 and MT2; MT1/2 KO) with the corresponding melatonin-proficient wild-type (WT) controls. By means of radioactive in situ hybridization, eN mRNA levels were found to be diminished in both MT1 and MT1/2 KO mice compared with WT controls suggesting stimulatory impacts of melatonin receptors on eN mRNA levels. Whereas eN mRNA levels increased during the day and peaked at night in WT and MT1 KO mice, eN mRNA levels at night were reduced and the peak was shifted toward day-time in double MT1/2 KO mice. These data suggest that the MT2 receptor subtype may play a role in the temporal regulation of eN mRNA availability. Notably, day-time locomotor activity was significantly higher in MT1/2 KO compared with WT mice. Our results suggest melatoninergic signaling as an interface between the purinergic system and the circadian system.
Collapse
Affiliation(s)
- Moran Homola
- Institute of Anatomy II, Dr. Senckenbergisches Chronomedizinisches Institut (SCI), Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Martina Pfeffer
- Institute of Anatomy II, Dr. Senckenbergisches Chronomedizinisches Institut (SCI), Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Simon C Robson
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 3 Blackfan Circle, Boston, MA 02215, USA
| | - Claudia Fischer
- Institute of Anatomy II, Dr. Senckenbergisches Chronomedizinisches Institut (SCI), Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Herbert Zimmermann
- Institute of Cell Biology and Neuroscience, Molecular and Cellular Neurobiology, Goethe University, Max-von-Laue-Strasse 13, 60438, Frankfurt am Main, Germany
| | - Horst-Werner Korf
- Institute of Anatomy II, Dr. Senckenbergisches Chronomedizinisches Institut (SCI), Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany.
| |
Collapse
|
36
|
Pfeffer M, Wicht H, von Gall C, Korf HW. Owls and larks in mice. Front Neurol 2015; 6:101. [PMID: 26029157 PMCID: PMC4432671 DOI: 10.3389/fneur.2015.00101] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 04/24/2015] [Indexed: 11/13/2022] Open
Abstract
Humans come in different chronotypes and, particularly, the late chronotype (the so-called owl) has been shown to be associated with several health risks. A number of studies show that laboratory mice also display various chronotypes. In mice as well as in humans, the chronotype shows correlations with the period length and rhythm stability. In addition, some mouse models for human diseases show alterations in their chronotypic behavior, which are comparable to those humans. Thus, analysis of the behavior of mice is a powerful tool to unravel the molecular and genetic background of the chronotype and the prevalence of risks and diseases that are associated with it. In this review, we summarize the correlation of chronotype with free-running period length and rhythm stability in inbred mouse strains, in mice with a compromised molecular clockwork, and in a mouse model for neurodegeneration.
Collapse
Affiliation(s)
- Martina Pfeffer
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany ; Dr. Senckenbergisches Chronomedizinisches Institut, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany
| | - Helmut Wicht
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany ; Dr. Senckenbergisches Chronomedizinisches Institut, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany
| | - Charlotte von Gall
- Institut für Anatomie II, Fachbereich Medizin, Heinrich Heine Universität , Düsseldorf , Germany
| | - Horst-Werner Korf
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany ; Dr. Senckenbergisches Chronomedizinisches Institut, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany
| |
Collapse
|
37
|
Expression of ectonucleotidases in the prosencephalon of melatonin-proficient C3H and melatonin-deficient C57Bl mice: spatial distribution and time-dependent changes. Cell Tissue Res 2015; 362:163-76. [PMID: 25959293 DOI: 10.1007/s00441-015-2179-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 03/20/2015] [Indexed: 12/24/2022]
Abstract
Extracellular purines (ATP, ADP, AMP and adenosine) are important signaling molecules in the CNS. Levels of extracellular purines are regulated by enzymes located at the cell surface referred to as ectonucleotidases. Time-dependent changes in their expression could profoundly influence the availability of extracellular purines and thereby purinergic signaling. Using radioactive in situ hybridization, we analyzed the mRNA distribution of the enzymes NTPDase1, -2 and -3 and ecto-5'-nucleotidase in the prosencephalon of two mouse strains: melatonin-proficient C3H and melatonin-deficient C57Bl. The mRNAs of these enzymes were localized to specific brain regions, such as hippocampus, striatum, medial habenula and ventromedial hypothalamus. NTPDase3 expression was more widely distributed than previously thought. All ectonucleotidases investigated revealed a prominent time-dependent expression pattern. In C3H, the mRNA expression of all four enzymes gradually increased during the day and peaked during the night. In contrast, in C57Bl, ecto-5'-nucleotidase expression peaked at the beginning of the day and gradually decreased to trough levels at night. Recording of locomotor activity revealed higher daytime activity of C57Bl than of C3H. Our results indicate that the expression of ectonucleotidases varies according to time and genotype and suggest that melatonin exerts modulatory effects associated with different regulations of purinergic signaling in the brain. These findings provide an important basis for further examination of the complexity of the purinergic system in the brain.
Collapse
|
38
|
Pfeffer M, Korf HW, von Gall C. Chronotype and stability of spontaneous locomotor activity rhythm in BMAL1-deficient mice. Chronobiol Int 2015; 32:81-91. [PMID: 25216070 DOI: 10.3109/07420528.2014.956218] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Behavior, physiological functions and cognitive performance change over the time of the day. These daily rhythms are either externally driven by rhythmic environmental cues such as the light/dark cycle (masking) or controlled by an internal circadian clock, the suprachiasmatic nucleus (SCN), which can be entrained to the light/dark cycle. Within a given species, there is genetically determined variability in the temporal preference for the onset of the active phase, the chronotype. The chronotype is the phase of entrainment between external and internal time and is largely regulated by the circadian clock. Genetic variations in clock genes and environmental influences contribute to the distribution of chronotypes in a given population. However, little is known about the determination of the chronotype, the stability of the locomotor rhythm and the re-synchronization capacity to jet lag in an animal without a functional endogenous clock. Therefore, we analyzed the chronotype of BMAL1-deficient mice (BMAL1-/-) as well as the effects of repeated experimental jet lag on locomotor activity rhythms. Moreover, light-induced period expression in the retina was analyzed to assess the responsiveness of the circadian light input system. In contrast to wild-type mice, BMAL1-/- showed a significantly later chronotype, adapted more rapidly to both phase advance and delay but showed reduced robustness of rhythmic locomotor activity after repeated phase shifts. However, photic induction of Period in the retina was not different between the two genotypes. Our findings suggest that a disturbed clockwork is associated with a late chronotype, reduced rhythm stability and higher vulnerability to repeated external desynchronization.
Collapse
Affiliation(s)
- Martina Pfeffer
- Dr. Senckenbergische Anatomie, Institut für Anatomie II, Fachbereich Medizin, Goethe-Universität , Frankfurt/Main , Germany
| | | | | |
Collapse
|
39
|
Belancio VP, Blask DE, Deininger P, Hill SM, Jazwinski SM. The aging clock and circadian control of metabolism and genome stability. Front Genet 2015; 5:455. [PMID: 25642238 PMCID: PMC4294216 DOI: 10.3389/fgene.2014.00455] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 12/11/2014] [Indexed: 11/13/2022] Open
Abstract
It is widely accepted that aging is characterized by a gradual decline in the efficiency and accuracy of biological processes, leading to deterioration of physiological functions and development of age-associated diseases. Age-dependent accumulation of genomic instability and development of metabolic syndrome are well-recognized components of the aging phenotype, both of which have been extensively studied. Existing findings strongly support the view that the integrity of the cellular genome and metabolic function can be influenced by light at night (LAN) and associated suppression of circadian melatonin production. While LAN is reported to accelerate aging by promoting age-associated carcinogenesis in several animal models, the specific molecular mechanism(s) of its action are not fully understood. Here, we review literature supporting a connection between LAN-induced central circadian disruption of peripheral circadian rhythms and clock function, LINE-1 retrotransposon-associated genomic instability, metabolic deregulation, and aging. We propose that aging is a progressive decline in the stability, continuity, and synchronization of multi-frequency oscillations in biological processes to a temporally disorganized state. By extension, healthy aging is the ability to maintain the most consistent, stable, and entrainable rhythmicity and coordination of these oscillations, at the molecular, cellular, and systemic levels.
Collapse
Affiliation(s)
- Victoria P Belancio
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane University New Orleans, LA, USA ; Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA
| | - David E Blask
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane University New Orleans, LA, USA ; Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA
| | - Prescott Deininger
- Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA ; Department of Epidemiology, Tulane University New Orleans, LA, USA
| | - Steven M Hill
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane University New Orleans, LA, USA ; Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA
| | - S Michal Jazwinski
- Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA ; Department of Medicine, Tulane University New Orleans, LA, USA
| |
Collapse
|
40
|
Hiragaki S, Baba K, Coulson E, Kunst S, Spessert R, Tosini G. Melatonin signaling modulates clock genes expression in the mouse retina. PLoS One 2014; 9:e106819. [PMID: 25203735 PMCID: PMC4159264 DOI: 10.1371/journal.pone.0106819] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 08/01/2014] [Indexed: 12/11/2022] Open
Abstract
Previous studies have shown that retinal melatonin plays an important role in the regulation of retinal daily and circadian rhythms. Melatonin exerts its influence by binding to G-protein coupled receptors named melatonin receptor type 1 and type 2 and both receptors are present in the mouse retina. Earlier studies have shown that clock genes are rhythmically expressed in the mouse retina and melatonin signaling may be implicated in the modulation of clock gene expression in this tissue. In this study we determined the daily and circadian expression patterns of Per1, Per2, Bmal1, Dbp, Nampt and c-fos in the retina and in the photoreceptor layer (using laser capture microdissection) in C3H-f+/+ and in melatonin receptors of knockout (MT1 and MT2) of the same genetic background using real-time quantitative RT-PCR. Our data indicated that clock and clock-controlled genes are rhythmically expressed in the retina and in the photoreceptor layer. Removal of melatonin signaling significantly affected the pattern of expression in the retina whereas in the photoreceptor layer only the Bmal1 circadian pattern of expression was affected by melatonin signaling removal. In conclusion, our data further support the notion that melatonin signaling may be important for the regulation of clock gene expression in the inner or ganglion cells layer, but not in photoreceptors.
Collapse
Affiliation(s)
- Susumu Hiragaki
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Kenkichi Baba
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Elise Coulson
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Stefanie Kunst
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Rainer Spessert
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Gianluca Tosini
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
- * E-mail:
| |
Collapse
|
41
|
Adamah-Biassi EB, Hudson RL, Dubocovich ML. Genetic deletion of MT1 melatonin receptors alters spontaneous behavioral rhythms in male and female C57BL/6 mice. Horm Behav 2014; 66:619-27. [PMID: 25200199 PMCID: PMC4698802 DOI: 10.1016/j.yhbeh.2014.08.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 08/25/2014] [Accepted: 08/29/2014] [Indexed: 10/24/2022]
Abstract
Behaviors vary over the 24h light/dark cycle and these temporal patterns reflect in part modulation by circadian neural circuits and hormones, such as melatonin. The goal of this study was to investigate the involvement of MT1 melatonin receptors in behavioral regulation by comparing male and female C57 wild type (WT) mice with C57 mice with genetic deletion of the MT1 receptor (MT1KO). A comprehensive array of fifteen distinct spontaneous behaviors was recorded continuously in the homecage over multiple days using the HomeCageScan system. Behaviors assessed were activity-like (i.e. come down, hang, jump, walk), exploration-like (i.e. dig, groom, rear up, sniff, stretch), resting-like (i.e. awake, remain low, rest, twitch) and ingestion-like (i.e. drink, eat). Phenotypic array and temporal distribution analysis revealed distinct behavioral rhythms that differed between WT and MT1KO mice. The rhythms were consistent from day to day in males and varied with the estrous cycle in females. We also studied the role of MT1 receptors on depressive and anxiety-like behaviors. Genetic deletion of MT1 receptors increased immobility time in the forced swim test and decreased the number of marbles buried in the marble burying test in both male and female C57 mice. We conclude that MT1 melatonin receptors are involved in neural pathways modulating diurnal rhythms of spontaneous behavior in the homecage as well as pathways regulating depressive and anxiolytic-like behaviors.
Collapse
Affiliation(s)
- E B Adamah-Biassi
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA
| | - R L Hudson
- Department of Physiology and Biophysics, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA
| | - M L Dubocovich
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA.
| |
Collapse
|
42
|
Tosini G, Owino S, Guillaume JL, Jockers R. Understanding melatonin receptor pharmacology: latest insights from mouse models, and their relevance to human disease. Bioessays 2014; 36:778-87. [PMID: 24903552 PMCID: PMC4151498 DOI: 10.1002/bies.201400017] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Melatonin, the neuro-hormone synthesized during the night, has recently seen an unexpected extension of its functional implications toward type 2 diabetes development, visual functions, sleep disturbances, and depression. Transgenic mouse models were instrumental for the establishment of the link between melatonin and these major human diseases. Most of the actions of melatonin are mediated by two types of G protein-coupled receptors, named MT1 and MT2 , which are expressed in many different organs and tissues. Understanding the pharmacology and function of mouse MT1 and MT2 receptors, including MT1 /MT2 heteromers, will be of crucial importance to evaluate the relevance of these mouse models for future therapeutic developments. This review will critically discuss these aspects, and give some perspectives including the generation of new mouse models.
Collapse
Affiliation(s)
- Gianluca Tosini
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA, USA
| | | | | | | |
Collapse
|
43
|
Comai S, Gobbi G. Unveiling the role of melatonin MT2 receptors in sleep, anxiety and other neuropsychiatric diseases: a novel target in psychopharmacology. J Psychiatry Neurosci 2014; 39:6-21. [PMID: 23971978 PMCID: PMC3868666 DOI: 10.1503/jpn.130009] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Melatonin (MLT) is a pleiotropic neurohormone controlling many physiological processes and whose dysfunction may contribute to several different diseases, such as neurodegenerative diseases, circadian and mood disorders, insomnia, type 2 diabetes and pain. Melatonin is synthesized by the pineal gland during the night and acts through 2 G-protein coupled receptors (GPCRs), MT1 (MEL1a) and MT2 (MEL1b). Although a bulk of research has examined the physiopathological effects of MLT, few studies have investigated the selective role played by MT1 and MT2 receptors. Here we have reviewed current knowledge about the implications of MT2 receptors in brain functions. METHODS We searched PubMed, Web of Science, Scopus, Google Scholar and articles' reference lists for studies on MT2 receptor ligands in sleep, anxiety, neuropsychiatric diseases and psychopharmacology, including genetic studies on the MTNR1B gene, which encodes the melatonin MT2 receptor. RESULTS These studies demonstrate that MT2 receptors are involved in the pathophysiology and pharmacology of sleep disorders, anxiety, depression, Alzheimer disease and pain and that selective MT2 receptor agonists show hypnotic and anxiolytic properties. LIMITATIONS Studies examining the role of MT2 receptors in psychopharmacology are still limited. CONCLUSION The development of novel selective MT2 receptor ligands, together with further preclinical in vivo studies, may clarify the role of this receptor in brain function and psychopharmacology. The superfamily of GPCRs has proven to be among the most successful drug targets and, consequently, MT2 receptors have great potential for pioneer drug discovery in the treatment of mental diseases for which limited therapeutic targets are currently available.
Collapse
Affiliation(s)
| | - Gabriella Gobbi
- Correspondence to: G. Gobbi, Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, 1033 Pine Ave. W, room 220, Montréal QC H3A 1A1;
| |
Collapse
|
44
|
Wicht H, Korf HW, Ackermann H, Ekhart D, Fischer C, Pfeffer M. Chronotypes and rhythm stability in mice. Chronobiol Int 2013; 31:27-36. [DOI: 10.3109/07420528.2013.820739] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
45
|
Kovacic P, Somanathan R. Cell signaling, receptors, electrical effects and therapy in circadian rhythm. J Recept Signal Transduct Res 2013; 33:267-75. [PMID: 23914781 DOI: 10.3109/10799893.2013.822890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Circadian rhythm has been the object of much attention. This review addresses the aspects of cell signaling, receptors, therapy and electrical effects in a multifaceted fashion. The pineal gland, which produces the important hormones melatonin and serotonin, exerts a prominent influence, in addition to the supraschiasmatic nucleus. Many aspects involve free radicals which have played a widespread role in biochemistry.
Collapse
Affiliation(s)
- Peter Kovacic
- Department of Chemistry and Biochemistry, San Diego State University, San Diego , CA , USA and
| | | |
Collapse
|
46
|
Wilking M, Ndiaye M, Mukhtar H, Ahmad N. Circadian rhythm connections to oxidative stress: implications for human health. Antioxid Redox Signal 2013; 19. [PMID: 23198849 PMCID: PMC3689169 DOI: 10.1089/ars.2012.4889] [Citation(s) in RCA: 185] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
SIGNIFICANCE Oxygen and circadian rhythmicity are essential in a myriad of physiological processes to maintain homeostasis, from blood pressure and sleep/wake cycles, down to cellular signaling pathways that play critical roles in health and disease. If the human body or cells experience significant stress, their ability to regulate internal systems, including redox levels and circadian rhythms, may become impaired. At cellular as well as organismal levels, impairment in redox regulation and circadian rhythms may lead to a number of adverse effects, including the manifestation of a variety of diseases such as heart diseases, neurodegenerative conditions, and cancer. RECENT ADVANCES Researchers have come to an understanding as to the basics of the circadian rhythm mechanism, as well as the importance of the numerous species of oxidative stress components. The effects of oxidative stress and dysregulated circadian rhythms have been a subject of intense investigations since they were first discovered, and recent investigations into the molecular mechanisms linking the two have started to elucidate the bases of their connection. CRITICAL ISSUES While much is known about the mechanics and importance of oxidative stress systems and circadian rhythms, the front where they interact has had very little research focused on it. This review discusses the idea that these two systems are together intricately involved in the healthy body, as well as in disease. FUTURE DIRECTIONS We believe that for a more efficacious management of diseases that have both circadian rhythm and oxidative stress components in their pathogenesis, targeting both systems in tandem would be far more successful.
Collapse
Affiliation(s)
- Melissa Wilking
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, USA
| | | | | | | |
Collapse
|
47
|
Kommedal S, Csernus V, Nagy AD. The embryonic pineal gland of the chicken as a model for experimental jet lag. Gen Comp Endocrinol 2013; 188:226-31. [PMID: 23619186 DOI: 10.1016/j.ygcen.2013.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 04/02/2013] [Accepted: 04/04/2013] [Indexed: 02/01/2023]
Abstract
The circadian clock in the chicken pineal model develops before hatching, at around the 17th embryonic day (ED17). By this stage, it runs in synchrony with environmental cues. To address if phase resetting mechanisms are comparable to those of post-hatched chicken, we investigated ED19 stage chicken embryos under 12h light:12h dark (LD), under constant darkness (DD), or under acute 4h phase delay of the LD condition (LD+4). The 24h mRNA-expression patterns of clock gene clock and of clock controlled genes Aanat and hiomt were analyzed with qRT-PCR. Under DD the rhythm of Aanat did not change significantly, however the 24h pattern of hiomt was altered. Clock shows a delayed response to DD with a phase-shift in its rhythm. After the first cycle under LD+4 conditions, the 24h patterns of Aa-nat and hiomt mRNA-s were phase delayed. Clock showed both acute and delayed changes in response to LD+4. These results show that the embryonic chicken pineal gland has a fully functioning clock mechanism, and that it is a good model for phase-change experiments. In addition it demonstrates that only one cycle of altered light schedule is sufficient to trigger changes within the molecular clock mechanisms of the chicken embryonic pineal model.
Collapse
Affiliation(s)
- Siri Kommedal
- Department of Anatomy, Medical School, University of Pécs, Szigeti út 12, H-7624 Pécs, Hungary.
| | | | | |
Collapse
|
48
|
Wu YH, Ursinus J, Zhou JN, Scheer FAJL, Ai-Min B, Jockers R, van Heerikhuize J, Swaab DF. Alterations of melatonin receptors MT1 and MT2 in the hypothalamic suprachiasmatic nucleus during depression. J Affect Disord 2013; 148:357-67. [PMID: 23357659 DOI: 10.1016/j.jad.2012.12.025] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Revised: 12/26/2012] [Accepted: 12/28/2012] [Indexed: 02/08/2023]
Abstract
BACKGROUND The pineal hormone melatonin regulates circadian rhythms, largely by feedback on the central biological clock of the brain, the hypothalamic suprachiasmatic nucleus (SCN). This feedback is mediated by the melatonin receptors, melatonin receptor 1 (MT1) and melatonin receptor 2 (MT2). The circadian system may play a role in the pathophysiology of mood disorders, and indeed, melatonin-receptor agonists are considered a potential therapy for depression. METHOD In order to investigate melatonin receptors in the SCN during depression, and their relationship to the major neuropeptides in the SCN, vasopressin (AVP) and vasoactive intestinal peptide (VIP), we studied the SCN in 14 depressed patients (five major depression and nine bipolar disorder) and 14 matched controls by immunocytochemistry. RESULTS We show here that hypothalamic MT2 receptor immunoreactivity was limited to SCN, the supraoptic nucleus and paraventricular nucleus. We found that numbers of MT1-immunoreactive (MT1-ir) cells and AVP and/or VIP-ir cells were increased in the central SCN in depression, but numbers of MT2-ir cells were not altered. Moreover, the number of MT1-ir cells, but not MT2-ir cells was negatively correlated with age at onset of depression, while positively correlated with disease duration. CONCLUSION AND LIMITATIONS: Although every post-mortem study has limitations, MT1 receptors appeared specifically increased in the SCN of depressed patients, and may increase during the course of the disease. These changes may be involved in the circadian disorders and contribute to the efficacy of MT agonists or melatonin in depression. Moreover, we suggest that melatonin receptor agonists for depression should be targeted towards the MT1 receptor selectively.
Collapse
Affiliation(s)
- Ying-Hui Wu
- Netherlands Institute for Neuroscience, Institute of Royal Netherlands Academy of Arts and Science, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Limited recovery of pineal function after regeneration of preganglionic sympathetic axons: evidence for loss of ganglionic synaptic specificity. J Neurosci 2013; 33:4867-74. [PMID: 23486957 DOI: 10.1523/jneurosci.3829-12.2013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The cervical sympathetic trunks (CSTs) contain axons of preganglionic neurons that innervate the superior cervical ganglia (SCGs). Because regeneration of CST fibers can be extensive and can reestablish certain specific patterns of SCG connections, restoration of end organ function would be expected. This expectation was examined with respect to the pineal gland, an organ innervated by the two SCGs. The activity of pineal serotonin N-acetyltransferase (NAT) exhibits a large circadian rhythm that is dependent on the sympathetic input of the gland, with high activity at night. Thirty-six hours after the CSTs were crushed bilaterally, nocturnal NAT was decreased by 99%. Three months later, enzyme activity had recovered only to 15% of control values, a recovery dependent on regeneration of CST fibers. Nevertheless, a small day/night rhythm was present in lesioned animals. Neither the density of the adrenergic innervation of the gland nor the ability of an adrenergic agonist to stimulate NAT activity was reduced in rats with regenerated CSTs. In addition, stimulation of the regenerated CST at a variety of frequencies was at least as effective in increasing NAT activity as seen with control nerves. These data suggest that the failure of pineal function to recover is not attributable to a quantitative deficit in the extent of reinnervation or synaptic efficacy. Rather, we suggest that there is some loss of specificity in the synaptic connections made in the SCG during reinnervation, resulting in a loss of the central neuronal information necessary for directing a normal NAT rhythm and thus normal pineal function.
Collapse
|
50
|
Richards J, Gumz ML. Mechanism of the circadian clock in physiology. Am J Physiol Regul Integr Comp Physiol 2013; 304:R1053-64. [PMID: 23576606 DOI: 10.1152/ajpregu.00066.2013] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
It has been well established that the circadian clock plays a crucial role in the regulation of almost every physiological process. It also plays a critical role in pathophysiological states including those of obesity and diabetes. Recent evidence has highlighted the potential for targeting the circadian clock as a potential drug target. New studies have also demonstrated the existence of "clock-independent effects" of the circadian proteins, leading to exciting new avenues of research in the circadian clock field in physiology. The goal of this review is to provide an introduction to and overview of the circadian clock in physiology, including mechanisms, targets, and role in disease states. The role of the circadian clocks in the regulation of the cardiovascular system, renal function, metabolism, the endocrine system, immune, and reproductive systems will be discussed.
Collapse
Affiliation(s)
- Jacob Richards
- Department of Medicine, University of Florida, Gainesville, FL, USA
| | | |
Collapse
|