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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.
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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
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Liu SM, Ifebi B, Johnson F, Xu A, Ho J, Yang Y, Schwartz G, Jo YH, Chua S. The gut signals to AGRP-expressing cells of the pituitary to control glucose homeostasis. J Clin Invest 2023; 133:e164185. [PMID: 36787185 PMCID: PMC10065075 DOI: 10.1172/jci164185] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 02/07/2023] [Indexed: 02/15/2023] Open
Abstract
Glucose homeostasis can be improved after bariatric surgery, which alters bile flow and stimulates gut hormone secretion, particularly FGF15/19. FGFR1 expression in AGRP-expressing cells is required for bile acids' ability to improve glucose control. We show that the mouse Agrp gene has 3 promoter/enhancer regions that direct transcription of each of their own AGRP transcripts. One of these Agrp promoters/enhancers, Agrp-B, is regulated by bile acids. We generated an Agrp-B knockin FLP/knockout allele. AGRP-B-expressing cells are found in endocrine cells of the pars tuberalis and coexpress diacylglycerol lipase B - an endocannabinoid biosynthetic enzyme - distinct from pars tuberalis thyrotropes. AGRP-B expression is also found in the folliculostellate cells of the pituitary's anterior lobe. Mice without AGRP-B were protected from glucose intolerance induced by high-fat feeding but not from excess weight gain. Chemogenetic inhibition of AGRP-B cells improved glucose tolerance by enhancing glucose-stimulated insulin secretion. Inhibition of the AGRP-B cells also caused weight loss. The improved glucose tolerance and reduced body weight persisted up to 6 weeks after cessation of the DREADD-mediated inhibition, suggesting the presence of a biological switch for glucose homeostasis that is regulated by long-term stability of food availability.
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Affiliation(s)
| | | | | | | | | | - Yunlei Yang
- Department of Medicine
- Department of Neuroscience, and
| | - Gary Schwartz
- Department of Medicine
- Department of Neuroscience, and
| | - Young Hwan Jo
- Department of Medicine
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, New York, USA
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3
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Stewart C, Marshall CJ. Seasonality of prolactin in birds and mammals. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:919-938. [PMID: 35686456 PMCID: PMC9796654 DOI: 10.1002/jez.2634] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/21/2022] [Accepted: 05/23/2022] [Indexed: 01/07/2023]
Abstract
In most animals, annual rhythms in environmental cues and internal programs regulate seasonal physiology and behavior. Prolactin, an evolutionarily ancient hormone, serves as a molecular correlate of seasonal timing in most species. Prolactin is highly pleiotropic with a wide variety of well-documented physiological effects; in a seasonal context prolactin is known to regulate annual changes in pelage and molt. While short-term homeostatic variation of prolactin secretion is under the control of the hypothalamus, long-term seasonal rhythms of prolactin are programmed by endogenous timers that reside in the pituitary gland. The molecular basis of these rhythms is generally understood to be melatonin dependent in mammals. Prolactin rhythmicity persists for several years in many species, in the absence of hypothalamic signaling. Such evidence in mammals has supported the hypothesis that seasonal rhythms in prolactin derive from an endogenous timer within the pituitary gland that is entrained by external photoperiod. In this review, we describe the conserved nature of prolactin signaling in birds and mammals and highlight its role in regulating multiple diverse physiological systems. The review will cover the current understanding of the molecular control of prolactin seasonality and propose a mechanism by which long-term rhythms may be generated in amniotes.
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Affiliation(s)
- Calum Stewart
- Institute of Biodiversity, Animal Health & Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Christopher J. Marshall
- Institute of Biodiversity, Animal Health & Comparative MedicineUniversity of GlasgowGlasgowUK
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Tortonese DJ. Hypophysial angiogenesis decodes annual time and underlies physiological adaptation to seasonal changes in the environment. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:939-951. [PMID: 35844178 PMCID: PMC9796326 DOI: 10.1002/jez.2639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 01/01/2023]
Abstract
Adaptation to annual changes in the environment is controlled by hypophysial hormones. In temperate zones, photoperiod is the primary external cue that regulates annual biological cycles and is translated by the pattern of melatonin secretion acting primarily in the hypophysial pars tuberalis. Angiogenic mechanisms within this tissue contribute to decode the melatonin signal through alternative splicing of the vascular endothelial growth factor A (VEGF-A) gene in both the pars tuberalis and the capillary loops of the infundibulum. The resulting melatonin-evoked differential productions of VEGF-A isoforms will induce seasonal remodeling of the vascular connection between the hypothalamus and hypophysis, and act as paracrine messengers in the pars distalis to generate the required seasonal endocrine response. Specifically, the long melatonin signal in winter upregulates antiangiogenic VEGF-A isoforms, which will reduce the number of vascular loops and the density of VEGF receptors in endocrine and folliculo-stellate (FS) cells, inhibit prolactin secretion, and stimulate FSH. In contrast, the short melatonin signal in summer upregulates proangiogenic VEGF-A isoforms that will increase the number of vascular loops and the density of VEGF receptors in endocrine and FS cells, stimulate prolactin secretion, and suppress FSH. A similar system has been identified in long day seasonal breeders, revealing that this is a conserved mechanism of adaptation across species. Thus, an angiogenesis-based, intrahypophysial system for annual time measurement controls local microvascular plasticity and conveys the photoperiodic signal readout from the melatonin sensitive pars tuberalis to the endocrine cells of the pars distalis to regulate seasonal adaptation to the environment.
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Affiliation(s)
- Domingo J. Tortonese
- Laboratories for Integrative Neuroscience and Endocrinology, Faculty of Health SciencesUniversity of BristolBristolUK
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Korf HW, Møller M. Arcuate nucleus, median eminence, and hypophysial pars tuberalis. HANDBOOK OF CLINICAL NEUROLOGY 2021; 180:227-251. [PMID: 34225932 DOI: 10.1016/b978-0-12-820107-7.00015-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The arcuate nucleus (ARC) is located in the mediobasal hypothalamus and forms a morphological and functional entity with the median eminence (ME), the ARC-ME. The ARC comprises several distinct types of neurons controlling prolactin release, food intake, and metabolism as well as reproduction and onset of puberty. The ME lacks a blood-brain barrier and provides an entry for peripheral signals (nutrients, leptin, ghrelin). ARC neurons are adjacent to the wall of the third ventricle. This facilitates the exchange of signals from and to the cerebrospinal fluid. The ventricular wall is composed of tanycytes that serve different functions. Axons of ARC neurons contribute to the tuberoinfundibular tract terminating in the ME on the hypophysial portal vessels (HPV) and establish one of the neurohumoral links between the hypothalamus and the pituitary. ARC neurons are reciprocally connected with several other hypothalamic nuclei, the brainstem, and reward pathways. The hypophysial pars tuberalis (PT) is attached to the ME and the HPV. The PT, an important interface of the neuroendocrine system, is mandatory for the control of seasonal functions. This contribution provides an update of our knowledge about the ARC-ME complex and the PT which, inter alia, is needed to understand the pathophysiology of metabolic diseases and reproduction.
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Affiliation(s)
- Horst-Werner Korf
- Center for Anatomy and Brain Research, Institute for Anatomy, Düsseldorf, Germany.
| | - Morten Møller
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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6
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West AC, Wood SH. Seasonal physiology: making the future a thing of the past. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Sáenz de Miera C, Sage-Ciocca D, Simonneaux V, Pévet P, Monecke S. Melatonin-independent Photoperiodic Entrainment of the Circannual TSH Rhythm in the Pars Tuberalis of the European Hamster. J Biol Rhythms 2018; 33:302-317. [DOI: 10.1177/0748730418766601] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Cristina Sáenz de Miera
- Department of Neurobiology of Rhythms, Institute for Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France
| | | | - Valérie Simonneaux
- Department of Neurobiology of Rhythms, Institute for Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France
| | - Paul Pévet
- Department of Neurobiology of Rhythms, Institute for Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France
| | - Stefanie Monecke
- Department of Neurobiology of Rhythms, Institute for Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France
- Institute of Chronoecology, Stuttgart, Germany, and Ludwig Maximilians University, Institute of Medical Psychology, Munich, Germany
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Korf HW. Signaling pathways to and from the hypophysial pars tuberalis, an important center for the control of seasonal rhythms. Gen Comp Endocrinol 2018; 258:236-243. [PMID: 28511899 DOI: 10.1016/j.ygcen.2017.05.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/09/2017] [Accepted: 05/12/2017] [Indexed: 11/28/2022]
Abstract
Seasonal (circannual) rhythms play an important role for the control of body functions (reproduction, metabolism, immune responses) in nearly all living organisms. Also humans are affected by the seasons with regard to immune responses and mental functions, the seasonal affective disorder being one of the most prominent examples. The hypophysial pars tuberalis (PT), an important interface between the hypophysial pars distalis and neuroendocrine centers in the brain, plays an essential role in the regulation of seasonal functions and may even be the seat of the circannual clock. Photoperiodic signals provide a major input to the PT. While the perception of these signals involves extraocular photoreceptors in non-mammalian species (birds, fish), mammals perceive photoperiodic signals exclusively in the retina. A multisynaptic pathway connects the retina with the pineal organ where photoperiodic signals are translated into the neurohormone melatonin that is rhythmically produced night by night and encodes the length of the night. Melatonin controls the functional activity of the mammalian PT by acting upon MT1 melatonin receptors. The PT sends its output signals via retrograde and anterograde pathways. The retrograde pathway targetting the hypothalamus employs TSH as messenger and controls a local hypothalamic T3 system. As discovered in Japanese quail, TSH triggers molecular cascades mediating thyroid hormone conversion in the ependymal cell layer of the infundibular recess of the third ventricle. The local accumulation of T3 in the mediobasal hypothalamus (MBH) appears to activate the gonadal axis by affecting the neuro-glial interaction between GnRH terminals and tanycytes in the median eminence. This retrograde pathway is conserved in photoperiodic mammals (sheep and hamsters), and even in non-photoperiodic laboratory mice provided that they are capable to synthesize melatonin. The anterograde pathway is implicated in the control of prolactin secretion, targets cells in the PD and supposedly employs small molecules as signal substances collectively denominated as "tuberalins". Several "tuberalin" candidates have been proposed, such as tachykinins, the secretory protein TAFA and endocannabinoids (EC). The PT-intrinsic EC system was first demonstrated in Syrian hamsters and shown to respond to photoperiodic changes. Subsequently, the EC system was also demonstrated in the PT of mice, rats and humans. To date, 2-arachidonoylglycerol (2-AG) appears as the most important endocannabinoid from the PT. Likely targets for the EC are folliculo-stellate cells that contain the CB1 receptor and appear to contact lactotroph cells. The CB1 receptor was also found on corticotroph cells which appear as a further target of the EC. Recently, the CB1 receptor was also localized to CRF-containing nerve fibers running in the outer zone of the median eminence. This finding suggests that the EC system of the PT contributes not only to the anterograde, but also to the retrograde pathway. Taken together, the results support the concept that the PT transmits its signals via a "cocktail" of messenger molecules which operate also in other brain areas and systems rather than through PT-specific "tuberalins". Furthermore, they may attribute a novel function to the PT, namely the modulation of the stress response and immune functions.
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Affiliation(s)
- Horst-Werner Korf
- Dr. Senckenbergische Anatomie, Institut für Anatomie II, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany.
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9
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Identification of an endocannabinoid system in the rat pars tuberalis—a possible interface in the hypothalamic-pituitary-adrenal system? Cell Tissue Res 2016; 368:115-123. [DOI: 10.1007/s00441-016-2544-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 11/23/2016] [Indexed: 01/23/2023]
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10
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Pava MJ, Makriyannis A, Lovinger DM. Endocannabinoid Signaling Regulates Sleep Stability. PLoS One 2016; 11:e0152473. [PMID: 27031992 PMCID: PMC4816426 DOI: 10.1371/journal.pone.0152473] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 03/15/2016] [Indexed: 11/18/2022] Open
Abstract
The hypnogenic properties of cannabis have been recognized for centuries, but endogenous cannabinoid (endocannabinoid) regulation of vigilance states is poorly characterized. We report findings from a series of experiments in mice measuring sleep with polysomnography after various systemic pharmacological manipulations of the endocannabinoid system. Rapid, unbiased scoring of vigilance states was achieved using an automated algorithm that we devised and validated. Increasing endocannabinoid tone with a selective inhibitor of monoacyglycerol lipase (JZL184) or fatty acid amide hydrolase (AM3506) produced a transient increase in non-rapid eye movement (NREM) sleep due to an augmentation of the length of NREM bouts (NREM stability). Similarly, direct activation of type 1 cannabinoid (CB1) receptors with CP47,497 increased NREM stability, but both CP47,497 and JZL184 had a secondary effect that reduced NREM sleep time and stability. This secondary response to these drugs was similar to the early effect of CB1 blockade with the antagonist/inverse agonist AM281, which fragmented NREM sleep. The magnitude of the effects produced by JZL184 and AM281 were dependent on the time of day this drug was administered. While activation of CB1 resulted in only a slight reduction in gamma power, CB1 blockade had dramatic effects on broadband power in the EEG, particularly at low frequencies. However, CB1 blockade did not significantly reduce the rebound in NREM sleep following total sleep deprivation. These results support the hypothesis that endocannabinoid signaling through CB1 is necessary for NREM stability but it is not necessary for sleep homeostasis.
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MESH Headings
- Algorithms
- Amidohydrolases/antagonists & inhibitors
- Amidohydrolases/metabolism
- Animals
- Benzodioxoles/pharmacology
- Drug Inverse Agonism
- Electrodes, Implanted
- Electroencephalography
- Male
- Mice
- Mice, Inbred C57BL
- Monoacylglycerol Lipases/antagonists & inhibitors
- Monoacylglycerol Lipases/metabolism
- Morpholines/pharmacology
- Piperidines/pharmacology
- Pyrazoles/pharmacology
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/metabolism
- Signal Transduction/drug effects
- Sleep/drug effects
- Sleep/physiology
- Sleep Deprivation/physiopathology
- Sleep, REM/drug effects
- Sleep, REM/physiology
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Affiliation(s)
- Matthew J. Pava
- Section on Synaptic Pharmacology, Laboratory for Integrative Neuroscience, Division of Intramural Biological and Clinical Research, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, United States of America
| | - Alexandros Makriyannis
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts, United States of America
| | - David M. Lovinger
- Section on Synaptic Pharmacology, Laboratory for Integrative Neuroscience, Division of Intramural Biological and Clinical Research, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, United States of America
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11
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Migaud M, Butrille L, Batailler M. Seasonal regulation of structural plasticity and neurogenesis in the adult mammalian brain: focus on the sheep hypothalamus. Front Neuroendocrinol 2015; 37:146-57. [PMID: 25462590 DOI: 10.1016/j.yfrne.2014.11.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/12/2014] [Accepted: 11/14/2014] [Indexed: 01/19/2023]
Abstract
To cope with variations in the environment, most mammalian species exhibit seasonal cycles in physiology and behaviour. Seasonal plasticity during the lifetime contributes to seasonal physiology. Over the years, our ideas regarding adult brain plasticity and, more specifically, hypothalamic plasticity have greatly evolved. Along with the two main neurogenic regions, namely the hippocampal subgranular and lateral ventricle subventricular zones, the hypothalamus, which is the central homeostatic regulator of numerous physiological functions that comprise sexual behaviours, feeding and metabolism, also hosts neurogenic niches. Both endogenous and exogenous factors, including the photoperiod, modulate the hypothalamic neurogenic capacities. The present review describes the effects of season on adult morphological plasticity and neurogenesis in seasonal species, for which the photoperiod is a master environmental cue for the successful programming of seasonal functions. In addition, the potential functional significance of adult neurogenesis in the mediation of the seasonal control of reproduction and feeding is discussed.
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Affiliation(s)
- Martine Migaud
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France; CNRS, UMR7247, F-37380 Nouzilly, France; Université de Tours, F-37041 Tours, France; Haras Nationaux, F-37380 Nouzilly, France.
| | - Lucile Butrille
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France; CNRS, UMR7247, F-37380 Nouzilly, France; Université de Tours, F-37041 Tours, France; Haras Nationaux, F-37380 Nouzilly, France
| | - Martine Batailler
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France; CNRS, UMR7247, F-37380 Nouzilly, France; Université de Tours, F-37041 Tours, France; Haras Nationaux, F-37380 Nouzilly, France
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12
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Bovolin P, Cottone E, Pomatto V, Fasano S, Pierantoni R, Cobellis G, Meccariello R. Endocannabinoids are Involved in Male Vertebrate Reproduction: Regulatory Mechanisms at Central and Gonadal Level. Front Endocrinol (Lausanne) 2014; 5:54. [PMID: 24782832 PMCID: PMC3995072 DOI: 10.3389/fendo.2014.00054] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 03/31/2014] [Indexed: 12/12/2022] Open
Abstract
Endocannabinoids (eCBs) are natural lipids regulating a large array of physiological functions and behaviors in vertebrates. The eCB system is highly conserved in evolution and comprises several specific receptors (type-1 and type-2 cannabinoid receptors), their endogenous ligands (e.g., anandamide and 2-arachidonoylglycerol), and a number of biosynthetic and degradative enzymes. In the last few years, eCBs have been described as critical signals in the control of male and female reproduction at multiple levels: centrally, by targeting hypothalamic gonadotropin-releasing-hormone-secreting neurons and pituitary, and locally, with direct effects on the gonads. These functions are supported by the extensive localization of cannabinoid receptors and eCB metabolic enzymes at different levels of the hypothalamic-pituitary-gonadal axis in mammals, as well as bonyfish and amphibians. In vivo and in vitro studies indicate that eCBs centrally regulate gonadal functions by modulating the gonadotropin-releasing hormone-gonadotropin-steroid network through direct and indirect mechanisms. Several proofs of local eCB regulation have been found in the testis and male genital tracts, since eCBs control Sertoli and Leydig cells activity, germ cell progression, as well as the acquisition of sperm functions. A comparative approach usually is a key step in the study of physiological events leading to the building of a general model. Thus, in this review, we summarize the action of eCBs at different levels of the male reproductive axis, with special emphasis, where appropriate, on data from non-mammalian vertebrates.
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Affiliation(s)
- Patrizia Bovolin
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
- Neuroscience Institute of Turin, University of Turin, Turin, Italy
- *Correspondence: Patrizia Bovolin, Department of Life Sciences and Systems Biology, University of Turin, via Accademia Albertina 13, 10123 Turin, Italy e-mail:
| | - Erika Cottone
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Valentina Pomatto
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Silvia Fasano
- Dipartimento di Medicina Sperimentale, Seconda Università di Napoli, Naples, Italy
| | - Riccardo Pierantoni
- Dipartimento di Medicina Sperimentale, Seconda Università di Napoli, Naples, Italy
| | - Gilda Cobellis
- Dipartimento di Medicina Sperimentale, Seconda Università di Napoli, Naples, Italy
| | - Rosaria Meccariello
- Dipartimento di Scienze Motorie e del Benessere, Università di Napoli Parthenope, Naples, Italy
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Yasuo S, Fischer C, Bojunga J, Iigo M, Korf HW. 2-Arachidonoyl glycerol sensitizes the pars distalis and enhances forskolin-stimulated prolactin secretion in Syrian hamsters. Chronobiol Int 2013; 31:337-42. [DOI: 10.3109/07420528.2013.852104] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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14
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Shalabi A, Fischer C, Korf HW, von Gall C. Melatonin-receptor-1-deficiency affects neurogenic differentiation factor immunoreaction in pancreatic islets and enteroendocrine cells of mice. Cell Tissue Res 2013; 353:483-91. [PMID: 23700151 DOI: 10.1007/s00441-013-1647-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 04/24/2013] [Indexed: 10/26/2022]
Abstract
Neurogenic differentiation factor (NeuroD) is a transcription factor involved in the differentiation of neurons and in the control of energy balance and metabolism. It plays a key role in type 1 and type 2 diabetes. Melatonin is an important rhythmic endocrine signal within the circadian system of mammals and modulates insulin secretion and glucose metabolism. In the mouse pars tuberalis, NeuroD mRNA levels show day/night variation, which is independent of the molecular clock gene mPER1 but depends on the functional melatonin receptor 1 (MT1). So far, little is known about the effect of melatonin on NeuroD synthesis in the gastrointestinal tract. Thus, NeuroD protein levels and cellular localization were analyzed by immunohistochemistry in pancreatic islets and duodenal enteroendocrine cells of MT1- and mPER1-deficienct mice. In addition, the localization of NeuroD-positive cells was analyzed by double-immunofluorescence and confocal laser microscopy. In duodenal enteroendocrine cells and pancreatic islets of WT and PER1-deficient mice, NeuroD immunoreaction showed a peak during the early subjective night. In contrast, this peak was absent in MT1-deficent mice. These data suggest that melatonin, by acting on MT1 receptors, affects NeuroD expression in the gastrointestinal tract and thus might contribute to circadian regulation in metabolic functions.
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Affiliation(s)
- Andree Shalabi
- Dr. Senckenbergische Anatomie, Institut für Anatomie II, Johann-Wolfgang-Goethe-Universität, Theodor-Stern-Kai 7, 60590, Frankfurt/M, Germany
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15
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Fischer C, Christ E, Korf HW, von Gall C. Tafa-3 encoding for a secretory peptide is expressed in the mouse pars tuberalis and is affected by melatonin 1 receptor deficiency. Gen Comp Endocrinol 2012; 177:98-103. [PMID: 22426341 DOI: 10.1016/j.ygcen.2012.02.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 02/24/2012] [Accepted: 02/25/2012] [Indexed: 11/22/2022]
Abstract
The hypophysial pars tuberalis (PT) is an important interface between neuroendocrine brain centers (hypothalamus, pineal organ) and the anterior lobe of the hypophysis (PD). The best investigated role of the PT is the control of seasonally changing functions. In mammals, melatonin secreted from the pineal organ represents a major input signal to the PT. By acting upon melatonin type 1 receptors (MT1) melatonin controls the functional activity of the PT. Most interestingly, the PT sends its output signals in two directions: via a "retrograde" pathway to the hypothalamus and via an "anterograde" pathway to the PD. TSH has been identified as "retrograde" messenger, while endocannabinoids function as messengers of the "anterograde" pathway. Here we show in mice that the PT expresses Tafa-3 encoding for a secretory peptide. In the PT of wild type mice Tafa-3 mRNA levels varied between day and night: they were low at mid-day and high at mid-night. This day/night difference was not observed in the PT of mice with a targeted deletion of the MT1 receptor indicating that Tafa-3 mRNA expression in the PT is controlled by melatonin acting through the MT1 receptor. Notably, Tafa-3 expression was not restricted to the PT, but was also found in other brain regions, such as the hippocampus, the habenular and thalamic nuclei. In these regions, Tafa-3 expression did not display a day/night difference and was not affected by MT1-deficiency. Thus, Tafa-3 expression appears to be controlled by region-specific mechanisms. Our data suggest that TAFA-3 is a signaling molecule from the PT and provides further evidence for the emerging concept that the PT rather than relying upon highly organ-specific messengers employs a cocktail of signaling molecules that also operate in other brain systems.
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Affiliation(s)
- Claudia Fischer
- Dr. Senckenbergische Anatomie, Institut für Anatomie II, Goethe-Universität, Theodor-Stern-Kai 7, D-60590 Frankfurt/M, Germany
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Battista N, Meccariello R, Cobellis G, Fasano S, Di Tommaso M, Pirazzi V, Konje JC, Pierantoni R, Maccarrone M. The role of endocannabinoids in gonadal function and fertility along the evolutionary axis. Mol Cell Endocrinol 2012; 355:1-14. [PMID: 22305972 DOI: 10.1016/j.mce.2012.01.014] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 12/05/2011] [Accepted: 01/16/2012] [Indexed: 02/07/2023]
Abstract
Endocannabinoids are natural lipids able to bind to cannabinoid and vanilloid receptors. Their biological actions at the central and peripheral level are under the tight control of the proteins responsible for their synthesis, transport and degradation. In the last few years, several reports have pointed out these lipid mediators as critical signals, together with sex hormones and cytokines, in various aspects of animal and human reproduction. The identification of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in reproductive cells and tissues of invertebrates, vertebrates and mammals highlights the key role played by these endogenous compounds along the evolutionary axis. Here, we review the main actions of endocannabinoids on female and male reproductive events, and discuss the interplay between them, steroid hormones and cytokines in regulating fertility. In addition, we discuss the involvement of endocannabinoid signalling in ensuring a correct chromatin remodeling, and hence a good DNA quality, in sperm cells.
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Affiliation(s)
- Natalia Battista
- Dipartimento di Scienze Biomediche Comparate, Università di Teramo, 64100 Teramo, Italy
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Wilkerson JL, Gentry KR, Dengler EC, Wallace JA, Kerwin AA, Kuhn MN, Zvonok AM, Thakur GA, Makriyannis A, Milligan ED. Immunofluorescent spectral analysis reveals the intrathecal cannabinoid agonist, AM1241, produces spinal anti-inflammatory cytokine responses in neuropathic rats exhibiting relief from allodynia. Brain Behav 2012; 2:155-77. [PMID: 22574283 PMCID: PMC3345359 DOI: 10.1002/brb3.44] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 01/30/2012] [Indexed: 12/30/2022] Open
Abstract
During pathological pain, the actions of the endocannabinoid system, including the cannabinoid 2 receptor (CB(2)R), leads to effective anti-allodynia and modifies a variety of spinal microglial and astrocyte responses. Here, following spinal administration of the CB(2)R compound, AM1241, we examined immunoreactive alterations in markers for activated p38 mitogen-activated protein kinase, interleukin-1β (IL-1β), the anti-inflammatory cytokine, interleukin-10 (IL-10) as well as degradative endocannabinoid enzymes, and markers for altered glial responses in neuropathic rats. In these studies, the dorsal horn of the spinal cord and dorsal root ganglia were examined. AM1241 produced profound anti-allodynia with corresponding immunoreactive levels of p38 mitogen-activated kinase, IL-1β, IL-10, the endocannabinoid enzyme monoacylglycerol lipase, and astrocyte activation markers that were similar to nonneuropathic controls. In contrast, spinal AM1241 did not suppress the increased microglial responses observed in neuropathic rats. The differences in fluorescent markers were determined within discrete anatomical regions by applying spectral analysis methods, which virtually eliminated nonspecific signal during the quantification of specific immunofluorescent intensity. These data reveal expression profiles that support the actions of intrathecal AM1241 control pathological pain through anti-inflammatory mechanisms by modulating critical glial factors, and additionally decrease expression levels of endocannabinoid degradative enzymes.
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Affiliation(s)
- Jenny L. Wilkerson
- Department of Neurosciences, Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131
| | - Katherine R. Gentry
- Department of Anesthesiology and Critical Care Medicine, Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131
| | - Ellen C. Dengler
- Department of Neurosciences, Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131
| | - James A. Wallace
- Department of Neurosciences, Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131
| | - Audra A. Kerwin
- Department of Neurosciences, Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131
| | - Megan N. Kuhn
- Department of Neurosciences, Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131
| | - Alexander M. Zvonok
- Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115
| | - Ganesh A. Thakur
- Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115
| | | | - Erin D. Milligan
- Department of Neurosciences, Health Sciences Center, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131
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Christ E, Korf HW, von Gall C. When does it start ticking? Ontogenetic development of the mammalian circadian system. PROGRESS IN BRAIN RESEARCH 2012; 199:105-118. [PMID: 22877661 DOI: 10.1016/b978-0-444-59427-3.00006-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Circadian rhythms in physiology and behavior ensure that vital functions are temporally synchronized with cyclic environmental changes. In mammals, the circadian system is conducted by a central circadian rhythm generator that resides in the hypothalamic suprachiasmatic nucleus (SCN) and controls multiple subsidiary circadian oscillators in the periphery. The molecular clockwork in SCN and peripheral oscillators consists of autoregulatory transcriptional/translational feedback loops of clock genes. The adult circadian system is synchronized to the astrophysical day by light whereas the fetal and neonatal circadian system entrains to nonphotic rhythmic maternal signals. This chapter reviews maturation and entrainment of the central circadian rhythm generator in the SCN and of peripheral oscillators during ontogenetic development.
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Affiliation(s)
- Elmar Christ
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Frankfurt am Main, Germany.
| | - Horst-Werner Korf
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Frankfurt am Main, Germany; Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
| | - Charlotte von Gall
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Frankfurt am Main, Germany; Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
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Suárez J, Ortíz O, Puente N, Bermúdez-Silva FJ, Blanco E, Fernández-Llebrez P, Grandes P, de Fonseca FR, Moratalla R. Distribution of diacylglycerol lipase alpha, an endocannabinoid synthesizing enzyme, in the rat forebrain. Neuroscience 2011; 192:112-31. [PMID: 21756982 DOI: 10.1016/j.neuroscience.2011.06.062] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Revised: 06/18/2011] [Accepted: 06/20/2011] [Indexed: 01/15/2023]
Abstract
1,2-diacylglycerol lipase alpha (DAGLα) is responsible for the biosynthesis and release of 2-arachidonoyl-glycerol (2-AG), the most abundant endocannabinoid in the brain. Although its expression has been detected in discrete regions, we showed here an integrated description of the distribution of DAGLα mRNA and protein in the rat forebrain using in situ hybridization histochemistry and immunohistochemistry. As novelty, we described the distribution of DAGLα protein expression in the olfactory system, the rostral migratory stream, neocortex, septum, thalamus, and hypothalamus. Similar DAGLα immunostaining pattern was also found in the brain of wild-type, but not of DAGLα knockout mice. Immunohistochemical data were correlated by the identification of DAGLα mRNA expression, for instance, in the somata of specific cells in olfactory structures, rostral migratory stream and neocortex, cells in some septal-basal-amygdaloid areas and the medial habenula, and magnocellular cells of the paraventricular hypothalamic nucleus. This widespread neuronal distribution of DAGLα is consistent with multiple roles for endocannabinoids in synaptic plasticity, including presynaptic inhibition of neurotransmitter release. We discuss our comparative analysis of the forebrain expression patterns of DAGLα and other components of the endocannabinoid signaling system, including the CB(1) receptor, monoacylglyceride lipase (MAGL), and fatty acid amide hydrolase (FAAH), providing some insight into the potential physiological and behavioral roles of this system.
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Affiliation(s)
- J Suárez
- Laboratorio de Medicina Regenerativa, Fundación IMABIS, Hospital Carlos Haya, Avenida Carlos Haya 82, 29010 Málaga, Spain.
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Yasuo S, Korf HW. The hypophysial pars tuberalis transduces photoperiodic signals via multiple pathways and messenger molecules. Gen Comp Endocrinol 2011; 172:15-22. [PMID: 21078321 DOI: 10.1016/j.ygcen.2010.11.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 11/08/2010] [Indexed: 11/26/2022]
Abstract
Located between the median eminence, the portal vessels, and the pars distalis (PD) of the hypophysis, the hypophysial pars tuberalis (PT) is an important center for transmission of photoperiodic information to neuroendocrine circuits involved in the control of reproduction, metabolism and behavior. Despite enormous and long lasting efforts, output pathways and messenger molecules from the PT have been unraveled only recently. Most interestingly, the PT sends its signals in two directions: via a "retrograde" pathway to the hypothalamus and via an "anterograde" pathway to the PD. TSH has been identified as a messenger of the "retrograde" pathway. As discovered in Japanese quail, TSH triggers molecular cascades mediating thyroid hormone conversion in the mediobasal hypothalamus (MBH) to activate the gonadal axis. These molecular mechanisms are conserved in photoperiodic mammals, and even in non-photoperiodic laboratory mice. The search for molecules of the "anterograde" pathway was for a long time focused on PT-specific neuropeptides, the so-called "tuberalins". The discovery of a PT-intrinsic endocannabinoid system in hamsters which is regulated by the photoperiod provides strong experimental evidence that the PT also synthesizes lipidergic messengers. To date, 2-arachidonoylglycerol (2-AG) appears as the most important lipidergic messenger from the PT. The primary target of 2-AG, the cannabinoid receptor 1 (CB1) is expressed in the hamster PD. A PT-intrinsic endocannabinoid system also exists in man and CB1 receptors are demonstrated in ACTH-producing cells and folliculo-stellate cells of the human PD. These data lend support to the hypothesis that endocannabinoids function as messengers of the anterograde pathway.
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Affiliation(s)
- Shinobu Yasuo
- Dr. Senckenbergische Anatomie, Institut für Anatomie II, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany.
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Localization of an endocannabinoid system in the hypophysial pars tuberalis and pars distalis of man. Cell Tissue Res 2010; 342:273-81. [DOI: 10.1007/s00441-010-1066-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 09/20/2010] [Indexed: 10/18/2022]
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