1
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Bolborea M, Langlet F. What is the physiological role of hypothalamic tanycytes in metabolism? Am J Physiol Regul Integr Comp Physiol 2021; 320:R994-R1003. [PMID: 33826442 DOI: 10.1152/ajpregu.00296.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In vertebrates, the energy balance process is tightly controlled by complex neural circuits that sense metabolic signals and adjust food intake and energy expenditure in line with the physiological requirements of optimal conditions. Within neural networks controlling energy balance, tanycytes are peculiar ependymoglial cells that are nowadays recognized as multifunctional players in the metabolic hypothalamus. However, the physiological function of hypothalamic tanycytes remains unclear, creating a number of ambiguities in the field. Here, we review data accumulated over the years that demonstrate the physiological function of tanycytes in the maintenance of metabolic homeostasis, opening up new research avenues. The presumed involvement of tanycytes in the pathophysiology of metabolic disorders and age-related neurodegenerative diseases will be finally discussed.
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Affiliation(s)
- Matei Bolborea
- Central and Peripheral Mechanisms of Neurodegeneration, INSERM U1118, Université de Strasbourg, Strasbourg, France.,School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Fanny Langlet
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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2
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Prezotto LD, Thorson JF, Prevot V, Redmer DA, Grazul-Bilska AT. Nutritionally induced tanycytic plasticity in the hypothalamus of adult ewes. Domest Anim Endocrinol 2020; 72:106438. [PMID: 32388344 DOI: 10.1016/j.domaniend.2020.106438] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/27/2019] [Accepted: 01/16/2020] [Indexed: 02/07/2023]
Abstract
The blood-brain barrier regulates the transport of molecules that convey global energetic status to the feeding circuitry within the hypothalamus. Capillaries within the median eminence (ME) and tight junctions between tanycytes lining the third ventricle (3V) are critical components of this barrier. Herein, we tested the hypothesis that altering the plane of nutrition results in the structural reorganization of tanycytes, tight junctions, and capillary structure within the medial basal hypothalamus. Proopiomelanocortin (POMC) neuronal content within the arcuate nucleus of the hypothalamus (ARC) was also assessed to test whether reduced nutritional status improved access of nutrients to the ARC, while decreasing the access of nutrients of overfed animals. Multiparous, nongestating ewes were stratified by weight and randomly assigned to dietary treatments offered for 75 d: 200% of dietary recommendations (overfed), 100% of dietary recommendations (control), or 60% of dietary recommendations (underfed). The number of POMC-expressing neurons within the ARC was increased (P ≤ 0.002) in underfed ewes. Overfeeding increased (P ≤ 0.01) tanycyte cellular process penetration and density compared with control and underfeeding as assessed using vimentin immunostaining. Immunostaining of tight junctions along the wall of the 3V did not differ (P = 0.32) between treatments. No differences were observed in capillary density (P = 0.21) or classification (P ≥ 0.47) within the ME. These results implicate that changes within the satiety center and morphology of tanycytes within the ARC occur as an adaptation to nutrient availability.
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Affiliation(s)
- L D Prezotto
- Nutritional & Reproductive Physiology Laboratory, Northern Agricultural Research Center, Montana State University, 3710 Assinniboine Road, Havre, MT 59501, USA.
| | - J F Thorson
- Nutritional & Reproductive Physiology Laboratory, Northern Agricultural Research Center, Montana State University, 3710 Assinniboine Road, Havre, MT 59501, USA
| | - V Prevot
- INSERM, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Centre, U1172, Lille, France
| | - D A Redmer
- Department of Animal Sciences, North Dakota State University, Fargo, ND 58108, USA
| | - A T Grazul-Bilska
- Department of Animal Sciences, North Dakota State University, Fargo, ND 58108, USA
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3
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Watkins LR, Orlandi C. Orphan G Protein Coupled Receptors in Affective Disorders. Genes (Basel) 2020; 11:E694. [PMID: 32599826 PMCID: PMC7349732 DOI: 10.3390/genes11060694] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/20/2020] [Accepted: 06/21/2020] [Indexed: 12/12/2022] Open
Abstract
G protein coupled receptors (GPCRs) are the main mediators of signal transduction in the central nervous system. Therefore, it is not surprising that many GPCRs have long been investigated for their role in the development of anxiety and mood disorders, as well as in the mechanism of action of antidepressant therapies. Importantly, the endogenous ligands for a large group of GPCRs have not yet been identified and are therefore known as orphan GPCRs (oGPCRs). Nonetheless, growing evidence from animal studies, together with genome wide association studies (GWAS) and post-mortem transcriptomic analysis in patients, pointed at many oGPCRs as potential pharmacological targets. Among these discoveries, we summarize in this review how emotional behaviors are modulated by the following oGPCRs: ADGRB2 (BAI2), ADGRG1 (GPR56), GPR3, GPR26, GPR37, GPR50, GPR52, GPR61, GPR62, GPR88, GPR135, GPR158, and GPRC5B.
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Affiliation(s)
| | - Cesare Orlandi
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA;
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4
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Xu L, Shen J, Dai S, Sun L, Chen X. Tetramethylpyrazine Attenuated Sevoflurane-Induced Neurotoxicity by Enhancing Autophagy through GPR50/CREB Pathway in SH-SY5Y Cells. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2020; 48:945-966. [PMID: 32476431 DOI: 10.1142/s0192415x20500457] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Tetramethylpyrazine has shown neuroprotective and axonal outgrowth-promoting effects and can improve cognitive deficit in a rat model of chronic hypoperfusion. However, the role of tetramethylpyrazine in sevoflurane-induced neurotoxicity is still vague. Therefore, this study was designed to investigate the effects and mechanisms of tetramethylpyrazine on sevoflurane-induced autophagy, apoptosis, and the expression of BACE1 and A[Formula: see text] in SH-SY5Y cells. We measured the expression levels of the apoptosis protein markers Bax and Bcl-2, autophagy protein markers Atg5 and LC3-II, BACE1, and A[Formula: see text] in SH-SY5Y cells after sevoflurane treatment and determined the effects of tetramethylpyrazine on sevoflurane-induced expression of these proteins after silencing GPR50 or Atg5 with siRNA in vitro. We found that exposure to 3.4% sevoflurane for 6 h decreased the expression of autophagy protein markers and increased the expression of the apoptosis protein markers, BACE1, and A[Formula: see text] in SH-SY5Y cells. The number of red puncta (autolysosomes) and yellow puncta (autophagosomes) in each SH-SY5Y cell decreased after transient transfection with the mRFP-GFP-LC3 expression plasmid. Silencing of GPR50 decreased the expression of pCREB, Atg5, and LC3-II, while silencing of Atg5 increased the expression of BACE1 and A[Formula: see text] in SH-SY5Y cells. Our results demonstrate that tetramethylpyrazine attenuated sevoflurane-induced neurotoxicity by enhancing autophagy through the GPR50/CREB pathway in SH-SY5Y cells.
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Affiliation(s)
- Lili Xu
- Department of Anesthesiology, Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, P. R. China
| | - Jianjun Shen
- Department of Anesthesiology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P. R. China
| | - Shaobing Dai
- Department of Anesthesiology, Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, P. R. China
| | - Lihong Sun
- Department of Anesthesiology, Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, P. R. China
| | - Xinzhong Chen
- Department of Anesthesiology, Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, P. R. China
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5
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Xie S, Fan W, He H, Huang F. Role of Melatonin in the Regulation of Pain. J Pain Res 2020; 13:331-343. [PMID: 32104055 PMCID: PMC7012243 DOI: 10.2147/jpr.s228577] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 01/20/2020] [Indexed: 12/15/2022] Open
Abstract
Melatonin is a pleiotropic hormone synthesized and secreted mainly by the pineal gland in vertebrates. Melatonin is an endogenous regulator of circadian and seasonal rhythms. Melatonin is involved in many physiological and pathophysiological processes demonstrating antioxidant, antineoplastic, anti-inflammatory, and immunomodulatory properties. Accumulating evidence has revealed that melatonin plays an important role in pain modulation through multiple mechanisms. In this review, we examine recent evidence for melatonin on pain regulation in various animal models and patients with pain syndromes, and the potential cellular mechanisms.
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Affiliation(s)
- Shanshan Xie
- Department of Pediatric Dentistry, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, People's Republic of China
| | - Wenguo Fan
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, People's Republic of China.,Department of Anesthesiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Hongwen He
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, People's Republic of China.,Department of Oral Anatomy and Physiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Fang Huang
- Department of Pediatric Dentistry, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, People's Republic of China
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6
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Kano M, Suga H, Ishihara T, Sakakibara M, Soen M, Yamada T, Ozaki H, Mitsumoto K, Kasai T, Sugiyama M, Onoue T, Tsunekawa T, Takagi H, Hagiwara D, Ito Y, Iwama S, Goto M, Banno R, Arima H. Tanycyte-Like Cells Derived From Mouse Embryonic Stem Culture Show Hypothalamic Neural Stem/Progenitor Cell Functions. Endocrinology 2019; 160:1701-1718. [PMID: 31135891 DOI: 10.1210/en.2019-00105] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/22/2019] [Indexed: 01/01/2023]
Abstract
Tanycytes have recently been accepted as neural stem/progenitor cells in the postnatal hypothalamus. Persistent retina and anterior neural fold homeobox (Rax) expression is characteristic of tanycytes in contrast to its transient expression of whole hypothalamic precursors. In this study, we found that Rax+ residual cells in the maturation phase of hypothalamic differentiation in mouse embryonic stem cell (mESC) cultures had similar characteristics to ventral tanycytes. They expressed typical neural stem/progenitor cell markers, including Sox2, vimentin, and nestin, and differentiated into mature neurons and glial cells. Quantitative RT-PCR analysis showed that Rax+ residual cells expressed Fgf-10, Fgf-18, and Lhx2, which are expressed by ventral tanycytes. They highly expressed tanycyte-specific genes Dio2 and Gpr50 compared with Rax+ early hypothalamic progenitor cells. Therefore, Rax+ residual cells in the maturation phase of hypothalamic differentiation were considered to be more differentiated and similar to late progenitor cells and tanycytes. They self-renewed and formed neurospheres when cultured with exogenous FGF-2. Additionally, these Rax+ neurospheres differentiated into three neuronal lineages (neurons, astrocytes, and oligodendrocytes), including neuropeptide Y+ neuron, that are reported to be differentiated from ventral tanycytes toward the arcuate nuclei. Thus, Rax+ residual cells were multipotent neural stem/progenitor cells. Rax+ neurospheres were stably passaged and retained high Sox2 expression even after multiple passages. These results suggest the successful induction of Rax+ tanycyte-like cells from mESCs [induced tanycyte-like (iTan) cells]. These hypothalamic neural stem/progenitor cells may have potential in regenerative medicine and as a research tool.
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Affiliation(s)
- Mayuko Kano
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hidetaka Suga
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takeshi Ishihara
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Drug Discovery Technologies, Drug Discovery and Disease Research Laboratory, Shionogi and Co., Ltd., Osaka, Japan
| | - Mayu Sakakibara
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mika Soen
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomiko Yamada
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hajime Ozaki
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kazuki Mitsumoto
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takatoshi Kasai
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mariko Sugiyama
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takeshi Onoue
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Taku Tsunekawa
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroshi Takagi
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Daisuke Hagiwara
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshihiro Ito
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shintaro Iwama
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Motomitsu Goto
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Ryoichi Banno
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroshi Arima
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
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7
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Melatonin MT1 receptor as a novel target in neuropsychopharmacology: MT1 ligands, pathophysiological and therapeutic implications, and perspectives. Pharmacol Res 2019; 144:343-356. [DOI: 10.1016/j.phrs.2019.04.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 03/06/2019] [Accepted: 04/11/2019] [Indexed: 12/15/2022]
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8
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Helfer G, Barrett P, Morgan PJ. A unifying hypothesis for control of body weight and reproduction in seasonally breeding mammals. J Neuroendocrinol 2019; 31:e12680. [PMID: 30585661 DOI: 10.1111/jne.12680] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/18/2018] [Accepted: 12/21/2018] [Indexed: 02/06/2023]
Abstract
Animals have evolved diverse seasonal variations in physiology and reproduction to accommodate yearly changes in environmental and climatic conditions. These changes in physiology are initiated by changes in photoperiod (daylength) and are mediated through melatonin, which relays photoperiodic information to the pars tuberalis of the pituitary gland. Melatonin drives thyroid-stimulating hormone transcription and synthesis in the pars tuberalis, which, in turn, regulates thyroid hormone and retinoic acid synthesis in the tanycytes lining the third ventricle of the hypothalamus. Seasonal variation in central thyroid hormone signalling is conserved among photoperiodic animals. Despite this, different species adopt divergent phenotypes to cope with the same seasonal changes. A common response amongst different species is increased hypothalamic cell proliferation/neurogenesis in short photoperiod. That cell proliferation/neurogenesis may be important for seasonal timing is based on (i) the neurogenic potential of tanycytes; (ii) the fact that they are the locus of striking seasonal morphological changes; and (iii) the similarities to mechanisms involved in de novo neurogenesis of energy balance neurones. We propose that a decrease in hypothalamic thyroid hormone and retinoic acid signalling initiates localised neurodegeneration and apoptosis, which leads to a reduction in appetite and body weight. Neurodegeneration induces compensatory cell proliferation from the neurogenic niche in tanycytes and new cells are born under short photoperiod. Because these cells have the potential to differentiate into a number of different neuronal phenotypes, this could provide a mechanistic basis to explain the seasonal regulation of energy balance, as well as reproduction. This cycle can be achieved without changes in thyroid hormone/retinoic acid and explains recent data obtained from seasonal animals held in natural conditions. However, thyroid/retinoic acid signalling is required to synchronise the cycles of apoptosis, proliferation and differentiation. Thus, hypothalamic neurogenesis provides a framework to explain diverse photoperiodic responses.
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Affiliation(s)
- Gisela Helfer
- School of Chemistry and Biosciences, University of Bradford, Bradford, UK
| | - Perry Barrett
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Peter J Morgan
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
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9
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Langlet F. Tanycyte Gene Expression Dynamics in the Regulation of Energy Homeostasis. Front Endocrinol (Lausanne) 2019; 10:286. [PMID: 31133987 PMCID: PMC6514105 DOI: 10.3389/fendo.2019.00286] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 04/18/2019] [Indexed: 01/01/2023] Open
Abstract
Animal survival relies on a constant balance between energy supply and energy expenditure, which is controlled by several neuroendocrine functions that integrate metabolic information and adapt the response of the organism to physiological demands. Polarized ependymoglial cells lining the floor of the third ventricle and sending a single process within metabolic hypothalamic parenchyma, tanycytes are henceforth described as key components of the hypothalamic neural network controlling energy balance. Their strategic position and peculiar properties convey them diverse physiological functions ranging from blood/brain traffic controllers, metabolic modulators, and neural stem/progenitor cells. At the molecular level, these functions rely on an accurate regulation of gene expression. Indeed, tanycytes are characterized by their own molecular signature which is mostly associated to their diverse physiological functions, and the detection of variations in nutrient/hormone levels leads to an adequate modulation of genetic profile in order to ensure energy homeostasis. The aim of this review is to summarize recent knowledge on the nutritional control of tanycyte gene expression.
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10
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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: 151] [Impact Index Per Article: 25.2] [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.
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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
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11
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Prevot V, Dehouck B, Sharif A, Ciofi P, Giacobini P, Clasadonte J. The Versatile Tanycyte: A Hypothalamic Integrator of Reproduction and Energy Metabolism. Endocr Rev 2018; 39:333-368. [PMID: 29351662 DOI: 10.1210/er.2017-00235] [Citation(s) in RCA: 147] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/12/2018] [Indexed: 12/16/2022]
Abstract
The fertility and survival of an individual rely on the ability of the periphery to promptly, effectively, and reproducibly communicate with brain neural networks that control reproduction, food intake, and energy homeostasis. Tanycytes, a specialized glial cell type lining the wall of the third ventricle in the median eminence of the hypothalamus, appear to act as the linchpin of these processes by dynamically controlling the secretion of neuropeptides into the portal vasculature by hypothalamic neurons and regulating blood-brain and blood-cerebrospinal fluid exchanges, both processes that depend on the ability of these cells to adapt their morphology to the physiological state of the individual. In addition to their barrier properties, tanycytes possess the ability to sense blood glucose levels, and play a fundamental and active role in shuttling circulating metabolic signals to hypothalamic neurons that control food intake. Moreover, accumulating data suggest that, in keeping with their putative descent from radial glial cells, tanycytes are endowed with neural stem cell properties and may respond to dietary or reproductive cues by modulating hypothalamic neurogenesis. Tanycytes could thus constitute the missing link in the loop connecting behavior, hormonal changes, signal transduction, central neuronal activation and, finally, behavior again. In this article, we will examine these recent advances in the understanding of tanycytic plasticity and function in the hypothalamus and the underlying molecular mechanisms. We will also discuss the putative involvement and therapeutic potential of hypothalamic tanycytes in metabolic and fertility disorders.
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Affiliation(s)
- Vincent Prevot
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
| | - Bénédicte Dehouck
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
| | - Ariane Sharif
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
| | - Philippe Ciofi
- Inserm, Neurocentre Magendie, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
| | - Paolo Giacobini
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
| | - Jerome Clasadonte
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Center, Lille, France.,University of Lille, FHU 1000 Days for Health, School of Medicine, Lille, France
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12
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The orphan GPR50 receptor promotes constitutive TGFβ receptor signaling and protects against cancer development. Nat Commun 2018; 9:1216. [PMID: 29572483 PMCID: PMC5865211 DOI: 10.1038/s41467-018-03609-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 02/28/2018] [Indexed: 11/28/2022] Open
Abstract
Transforming growth factor-β (TGFβ) signaling is initiated by the type I, II TGFβ receptor (TβRI/TβRII) complex. Here we report the formation of an alternative complex between TβRI and the orphan GPR50, belonging to the G protein-coupled receptor super-family. The interaction of GPR50 with TβRI induces spontaneous TβRI-dependent Smad and non-Smad signaling by stabilizing the active TβRI conformation and competing for the binding of the negative regulator FKBP12 to TβRI. GPR50 overexpression in MDA-MB-231 cells mimics the anti-proliferative effect of TβRI and decreases tumor growth in a xenograft mouse model. Inversely, targeted deletion of GPR50 in the MMTV/Neu spontaneous mammary cancer model shows decreased survival after tumor onset and increased tumor growth. Low GPR50 expression is associated with poor survival prognosis in human breast cancer irrespective of the breast cancer subtype. This describes a previously unappreciated spontaneous TGFβ-independent activation mode of TβRI and identifies GPR50 as a TβRI co-receptor with potential impact on cancer development. Transforming growth factor-β (TGFβ) regulates many cellular processes. Here the authors show that the orphan G-protein coupled receptor GPR50 can activate the TGFβ receptor I, in the absence of TGFβ, by stabilizing its active conformation and show antitumor activity in a mouse model of breast cancer.
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13
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Gautier C, Guenin SP, Riest-Fery I, Perry TJ, Legros C, Nosjean O, Simonneaux V, Grützner F, Boutin JA. Characterization of the Mel1c melatoninergic receptor in platypus (Ornithorhynchus anatinus). PLoS One 2018. [PMID: 29529033 PMCID: PMC5846726 DOI: 10.1371/journal.pone.0191904] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Melatonin is a neurohormone produced in both animals and plants. It binds at least three G-protein-coupled receptors: MT1 and MT2, and Mel1cGPR. Mammalian GPR50 evolved from the reptilian/avian Mel1c and lost its capacity to bind melatonin in all the therian mammal species that have been tested. In order to determine if binding is lost in the oldest surviving mammalian lineage of monotremes we investigated whether the melatonin receptor has the ability to bind melatonin in the platypus (Ornithorhynchus anatinus), and evaluated its pharmacological profile. Sequence and phylogenetic analysis showed that platypus has in fact retained the ancestral Mel1c and has the capacity to bind melatonin similar to other mammalian melatonin receptors (MT1 and MT2), with an affinity in the 1 nM range. We also investigated the binding of a set of melatoninergic ligands used previously to characterize the molecular pharmacology of the melatonin receptors from sheep, rats, mice, and humans and found that the general profiles of these compounds make Mel1c resemble human MT1 more than MT2. This work shows that the loss of GPR50 binding evolved after the divergence of monotremes less than 190MYA in therian mammals.
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MESH Headings
- Animals
- Base Sequence
- COS Cells
- Chlorocebus aethiops
- Cloning, Molecular/methods
- Melatonin/metabolism
- Phylogeny
- Platypus/genetics
- Platypus/metabolism
- Protein Binding
- Receptor, Melatonin, MT1/chemistry
- Receptor, Melatonin, MT1/genetics
- Receptor, Melatonin, MT1/metabolism
- Receptor, Melatonin, MT2/chemistry
- Receptor, Melatonin, MT2/genetics
- Receptor, Melatonin, MT2/metabolism
- Receptors, Melatonin/chemistry
- Receptors, Melatonin/genetics
- Receptors, Melatonin/metabolism
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Affiliation(s)
- Célia Gautier
- PEX Biotechnologie Chimie & Biologie, Institut de Recherches Servier, Croissy sur Seine, France
- Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Sophie-Penelope Guenin
- PEX Biotechnologie Chimie & Biologie, Institut de Recherches Servier, Croissy sur Seine, France
| | - Isabelle Riest-Fery
- PEX Biotechnologie Chimie & Biologie, Institut de Recherches Servier, Croissy sur Seine, France
| | - Tahlia Jade Perry
- School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Céline Legros
- PEX Biotechnologie Chimie & Biologie, Institut de Recherches Servier, Croissy sur Seine, France
| | - Olivier Nosjean
- PEX Biotechnologie Chimie & Biologie, Institut de Recherches Servier, Croissy sur Seine, France
- Institut de Recherches Internationales Servier, Suresnes, France
| | - Valerie Simonneaux
- Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Frank Grützner
- School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Jean A. Boutin
- PEX Biotechnologie Chimie & Biologie, Institut de Recherches Servier, Croissy sur Seine, France
- Institut de Recherches Internationales Servier, Suresnes, France
- * E-mail:
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14
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Saxena VK, Kumar D, Naqvi SMK. Molecular characterization of GPR50 gene and study of its comparative genetic variability in sheep breeds adapted to different thermo-contrasting climatic regimens. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2017; 61:701-707. [PMID: 27678249 DOI: 10.1007/s00484-016-1247-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/09/2016] [Accepted: 09/09/2016] [Indexed: 06/06/2023]
Abstract
GPR50, formerly known as a melatonin-related receptor, is one of the three subtypes of melatonin receptor subfamily, together with MTNR1A and MTNR1B. GPR50, despite its high identity with the melatonin receptor family, does not bind melatonin and is considered to be an ortholog of MTNR1C in mammals. GPR50-expressing cells have been found in the dorsomedial nucleus of the hypothalamus, the periventricular nucleus, and the median eminence. Genetic and functional evidence have been recently investigated linking GPR50 to adaptive thermogenesis and torpor, but still, it is an orphan receptor and is yet to be studied conclusively. The aims of the study were to characterize the GPR50 gene of sheep and to study the sequence variability of the gene in Indian sheep breeds of two different thermo-varied agroclimatic conditions. Genomic DNA isolation was done and a 791-bp sequence was amplified using self-designed primers and SNP profiling done out of samples of all the breeds to study the relative frequency of SNPs in each of the breed. Five important non-synonymous mutations were observed in the various breeds studied. T698G, G1097A, G1270A, G1318A, and C1334G lead to the following substitution: valine by glycine, arginine by glutamine, threonine by alanine, isoleucine by valine, and serine by cytosine, respectively. Two synonymous mutations (T663G and C888T) were also observed in some of the studied breeds. G1270A and C888T were the most prevalent SNPs observed in nearly all of the breeds. C888T SNPs were observed in higher prevalence in Chokla, Marwari, and Magra in comparison to Gaddi and Bharat Merino. A PolyPhen-2 analysis, which is used to assess the potential damaging nature of an SNP, revealed that mutation T698G and G1270A were benign while G1097A, G1318A, and C1334G were damaging with a score of 0.987, 0.993, and 0.739, respectively. A 3-D homology model of the protein was prepared using c4zwjA (UniProt sequence ID) as a template using the online version of Phyre2 protein modeling software. The structure demonstrated closed similarity with other G-coupled receptor and it had a 45 % α-helical content. G1270A and C888T may be taken up for SNP correlation in a larger population study for their association with heat stress protection.
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Affiliation(s)
- Vijay Kumar Saxena
- Molecular Physiology Laboratory, Division of Animal Physiology and Biochemistry, ICAR-Central Sheep and Wool Research Institute, Avikanagar, 304501, Malpura, Tonk Distt, Rajasthan, India.
| | - Davendra Kumar
- Molecular Physiology Laboratory, Division of Animal Physiology and Biochemistry, ICAR-Central Sheep and Wool Research Institute, Avikanagar, 304501, Malpura, Tonk Distt, Rajasthan, India
| | - S M K Naqvi
- Molecular Physiology Laboratory, Division of Animal Physiology and Biochemistry, ICAR-Central Sheep and Wool Research Institute, Avikanagar, 304501, Malpura, Tonk Distt, Rajasthan, India
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15
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Khan MZ, He L. Neuro-psychopharmacological perspective of Orphan receptors of Rhodopsin (class A) family of G protein-coupled receptors. Psychopharmacology (Berl) 2017; 234:1181-1207. [PMID: 28289782 DOI: 10.1007/s00213-017-4586-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 02/27/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND In the central nervous system (CNS), G protein-coupled receptors (GPCRs) are the most fruitful targets for neuropsychopharmacological drug development. Rhodopsin (class A) is the most studied class of GPCR and includes orphan receptors for which the endogenous ligand is not known or is unclear. Characterization of orphan GPCRs has proven to be challenging, and the production pace of GPCR-based drugs has been incredibly slow. OBJECTIVE Determination of the functions of these receptors may provide unexpected insight into physiological and neuropathological processes. Advances in various methods and techniques to investigate orphan receptors including in situ hybridization and knockdown/knockout (KD/KO) showed extensive expression of these receptors in the mammalian brain and unmasked their physiological and neuropathological roles. Due to these rapid progress and development, orphan GPCRs are rising as a new and promising class of drug targets for neurodegenerative diseases and psychiatric disorders. CONCLUSION This review presents a neuropsychopharmacological perspective of 26 orphan receptors of rhodopsin (class A) family, namely GPR3, GPR6, GPR12, GPR17, GPR26, GPR35, GPR39, GPR48, GPR49, GPR50, GPR52, GPR55, GPR61, GPR62, GPR63, GPR68, GPR75, GPR78, GPR83, GPR84, GPR85, GPR88, GPR153, GPR162, GPR171, and TAAR6. We discussed the expression of these receptors in mammalian brain and their physiological roles. Furthermore, we have briefly highlighted their roles in neurodegenerative diseases and psychiatric disorders including Alzheimer's disease, Parkinson's disease, neuroinflammation, inflammatory pain, bipolar and schizophrenic disorders, epilepsy, anxiety, and depression.
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Affiliation(s)
- Muhammad Zahid Khan
- Department of Pharmacology, China Pharmaceutical University, No. 24 Tong Jia Xiang, Nanjing, Jiangsu Province, 210009, China.
| | - Ling He
- Department of Pharmacology, China Pharmaceutical University, No. 24 Tong Jia Xiang, Nanjing, Jiangsu Province, 210009, China
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16
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Khan MZ, He L, Zhuang X. The emerging role of GPR50 receptor in brain. Biomed Pharmacother 2016; 78:121-128. [PMID: 26898433 DOI: 10.1016/j.biopha.2016.01.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 01/06/2016] [Indexed: 01/08/2023] Open
Abstract
GPR50 receptor one of the member of G protein-coupled receptors (GPCRs) is extensively expressed in the pituitary, hypothalamus,cortex, midbrain, pons, amygdala, and in several brainstem nuclei. The exact function of this receptor in brain is remains unclear. This review presents current knowledge regarding the function of GPR50 receptor in brain, with a focus on role of this receptor in the hypothalamus-pituitary-adrenal (HPA) axis and the glucocorticoid receptor (GR) signaling, leptin signaling, adaptive thermogenesis, torpor, neurite outgrowth, and self-renewal and neuronal differentiation of neural progenitor cells NPCs. Although the results are encouraging, further research is needed to clarify GPR50 role in neurobiology of mood disorders, adaptive thermogenesis, torpor, and in the pathophysiology of neurological disorders.
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Affiliation(s)
- Muhammad Zahid Khan
- Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China.
| | - Ling He
- China Pharmaceutical University, Department of Pharmacology, No. 24 Tong Jia Xiang, Nanjing,Jiang Su Province 210009, China
| | - Xuxu Zhuang
- China Pharmaceutical University, Department of Pharmacology, No. 24 Tong Jia Xiang, Nanjing,Jiang Su Province 210009, China
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17
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Goodman T, Hajihosseini MK. Hypothalamic tanycytes-masters and servants of metabolic, neuroendocrine, and neurogenic functions. Front Neurosci 2015; 9:387. [PMID: 26578855 PMCID: PMC4624852 DOI: 10.3389/fnins.2015.00387] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 10/05/2015] [Indexed: 11/13/2022] Open
Abstract
There is a resurgent interest in tanycytes, a radial glial-like cell population occupying the floor and ventro-lateral walls of the third ventricle (3V). Tanycytes reside in close proximity to hypothalamic neuronal nuclei that regulate appetite and energy expenditure, with a subset sending projections into these nuclei. Moreover, tanycytes are exposed to 3V cerebrospinal fluid and have privileged access to plasma metabolites and hormones, through fenestrated capillaries. Indeed, some tanycytes act as conduits for trafficking of these molecules into the brain parenchyma. Tanycytes can also act as neural stem/progenitor cells, supplying the postnatal and adult hypothalamus with new neurons. Collectively, these findings suggest that tanycytes regulate and integrate important trophic and metabolic processes and possibly endow functional malleability to neuronal circuits of the hypothalamus. Hence, manipulation of tanycyte biology could provide a valuable tool for modulating hypothalamic functions such as energy uptake and expenditure in order to tackle prevalent eating disorders such as obesity and anorexia.
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Affiliation(s)
- Timothy Goodman
- School of Biological Sciences, University of East Anglia Norwich, UK
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18
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Sensitivity to the photoperiod and potential migratory features of neuroblasts in the adult sheep hypothalamus. Brain Struct Funct 2015; 221:3301-14. [DOI: 10.1007/s00429-015-1101-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 08/27/2015] [Indexed: 12/14/2022]
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19
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Batailler M, Droguerre M, Baroncini M, Fontaine C, Prevot V, Migaud M. DCX-expressing cells in the vicinity of the hypothalamic neurogenic niche: a comparative study between mouse, sheep, and human tissues. J Comp Neurol 2014; 522:1966-85. [PMID: 24288185 DOI: 10.1002/cne.23514] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Revised: 11/27/2013] [Accepted: 11/27/2013] [Indexed: 12/31/2022]
Abstract
Neural stem and precursor cells persist postnatally throughout adulthood and are capable of responding to numerous endogenous and exogenous signals by modifying their proliferation and differentiation. Whereas adult neurogenesis has been extensively studied in the dentate gyrus of the hippocampal formation and in the subventricular zone adjacent to the wall of the lateral ventricles, we and others have recently reported constitutive adult neurogenesis in other brain structures, including the hypothalamus. In this study, we used immunohistochemistry to study the expression of the neuroblast marker doublecortin (DCX), and compared its expression pattern in adult ovine, mouse, and human hypothalamic tissues. Our results indicate that DCX-positive cells resembling immature and developing neurons occur in a wide range of hypothalamic nuclei in all three species, although with different distribution patterns. In addition, the morphology of DCX-positive cells varied depending on their location. DCX-positive cells near the third ventricle had the morphology of very immature neuroblasts, a round shape with no processes, whereas those located deeper in the parenchyma such as in the ventromedial nucleus were fusiform and showed a bipolar morphology. Extending this observation, we showed that among the cohort of immature neurons entering the ventromedial nucleus, some appeared to undergo maturation, as revealed by the partial colocalization of DCX with markers of more mature neurons, e.g., human neuronal protein C and D (HuC/D). This study provides further confirmation of the existence of an adult hypothalamic neurogenic niche and argues for the potential existence of a migratory path within the hypothalamus.
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Affiliation(s)
- Martine Batailler
- INRA, Unité Mixte de Recherche (UMR) 85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France; Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 7247, F-37380, Nouzilly, France; Université de Tours, F-37041, Tours, France; Institut Français du Cheval et de l'équitation (IFCE), F-37380, Nouzilly, France
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20
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Miranda-Angulo AL, Byerly MS, Mesa J, Wang H, Blackshaw S. Rax regulates hypothalamic tanycyte differentiation and barrier function in mice. J Comp Neurol 2014; 522:876-99. [PMID: 23939786 DOI: 10.1002/cne.23451] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 07/12/2013] [Accepted: 08/02/2013] [Indexed: 12/30/2022]
Abstract
The wall of the ventral third ventricle is composed of two distinct cell populations: tanycytes and ependymal cells. Tanycytes regulate many aspects of hypothalamic physiology, but little is known about the transcriptional network that regulates their development and function. We observed that the retina and anterior neural fold homeobox transcription factor (Rax) is selectively expressed in hypothalamic tanycytes, and showed a complementary pattern of expression to markers of hypothalamic ependymal cells, such as Rarres2 (retinoic acid receptor responder [tazarotene induced] 2). To determine whether Rax controls tanycyte differentiation and function, we generated Rax haploinsufficient mice and examined their cellular and molecular phenotype in adulthood. These mice appeared grossly normal, but careful examination revealed a thinning of the third ventricular wall and reduction of both tanycyte and ependymal markers. These experiments show that Rax is required for hypothalamic tanycyte and ependymal cell differentiation. Rax haploinsufficiency also resulted in the ectopic presence of ependymal cells in the α2 tanycytic zone, where few ependymal cells are normally found, suggesting that Rax is selectively required for α2 tanycyte differentiation. These changes in the ventricular wall were associated with reduced diffusion of Evans Blue tracer from the ventricle to the hypothalamic parenchyma, with no apparent repercussion on the gross anatomical or behavioral phenotype of these mice. In conclusion, we have provided evidence that Rax is required for the normal differentiation and patterning of hypothalamic tanycytes and ependymal cells, as well as for maintenance of the cerebrospinal fluid-hypothalamus barrier.
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Affiliation(s)
- Ana L Miranda-Angulo
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21287; Institute of Medical Research, Universidad de Antioquia, School of Medicine, Medellín, Colombia 05001000
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21
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Rønnekleiv OK, Fang Y, Zhang C, Nestor CC, Mao P, Kelly MJ. Research resource: Gene profiling of G protein-coupled receptors in the arcuate nucleus of the female. Mol Endocrinol 2014; 28:1362-80. [PMID: 24933249 PMCID: PMC4116592 DOI: 10.1210/me.2014-1103] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The hypothalamic arcuate nucleus controls many critical homeostatic functions including energy homeostasis, reproduction, and motivated behavior. Although G protein-coupled receptors (GPCRs) are involved in the regulation of these functions, relatively few of the GPCRs have been identified specifically within the arcuate nucleus. Here, using TaqMan low-density arrays we quantified the mRNA expression of nonolfactory GPCRs in mouse arcuate nucleus. An unprecedented number of GPCRs (total of 292) were found to be expressed, of which 183 were known and 109 were orphan GPCRs. The known GPCR genes expressed were classified into several functional clusters including hormone/neurotransmitter, growth factor, angiogenesis and vasoactivity, inflammation and immune system, and lipid messenger receptors. The plethora of orphan genes expressed in the arcuate nucleus were classified into 5 structure-related classes including class A (rhodopsin-like), class B (adhesion), class C (other GPCRs), nonsignaling 7-transmembrane chemokine-binding proteins, and other 7-transmembrane proteins. Therefore, for the first time, we provide a quantitative estimate of the numerous GPCRs expressed in the hypothalamic arcuate nucleus. Finally, as proof of principle, we documented the expression and function of one of these receptor genes, the glucagon-like peptide 1 receptor (Glp1r), which was highly expressed in the arcuate nucleus. Single-cell RT-PCR revealed that Glp1r mRNA was localized in proopiomelanocortin neurons, and using whole-cell recording we found that the glucagon-like peptide 1-selective agonist exendin-4 robustly excited proopiomelanocortin neurons. Thus, the quantitative GPCR data emphasize the complexity of the hypothalamic arcuate nucleus and furthermore provide a valuable resource for future neuroendocrine/endocrine-related experiments.
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Affiliation(s)
- Oline K Rønnekleiv
- Department of Physiology and Pharmacology (O.K.R., Y.F., C.Z., C.CN., P.M., M.J.K.), Oregon Health and Science University, Portland, Oregon 97239; and Division of Neuroscience (O.K.R., P.M., M.J.K.), Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006
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22
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He H, Jiang D, Kang B, Ma R, Bai L, Wang X, Zhao L. Gene expression profiling of melatonin receptor subtypes in the ovarian hierarchical follicles of the Sichuan white goose. Anim Reprod Sci 2014; 145:62-8. [DOI: 10.1016/j.anireprosci.2013.12.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 12/15/2013] [Accepted: 12/22/2013] [Indexed: 01/20/2023]
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23
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Sharif A, Ojeda SR, Prevot V. Neurogenesis and Gliogenesis in the Postnatal Hypothalamus: A New Level of Plasticity for the Regulation of Hypothalamic Function? ENDOGENOUS STEM CELL-BASED BRAIN REMODELING IN MAMMALS 2014. [DOI: 10.1007/978-1-4899-7399-3_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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24
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Bolborea M, Dale N. Hypothalamic tanycytes: potential roles in the control of feeding and energy balance. Trends Neurosci 2013; 36:91-100. [PMID: 23332797 PMCID: PMC3605593 DOI: 10.1016/j.tins.2012.12.008] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/11/2012] [Accepted: 12/18/2012] [Indexed: 02/08/2023]
Abstract
Tanycytes, glial-like cells that line the third ventricle, are emerging as components of the hypothalamic networks that control body weight and energy balance. They contact the cerebrospinal fluid (CSF) and send processes that come into close contact with neurons in the arcuate and ventromedial hypothalamic nuclei. Tanycytes are glucosensitive and are able to respond to transmitters associated with arousal and the drive to feed. At least some tanycytes are stem cells and, in the median eminence, may be stimulated by diet to generate new neurons. The quest is on to understand how tanycytes detect and respond to changes in energy balance and how they communicate with the rest of the nervous system to effect their functions.
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Affiliation(s)
- Matei Bolborea
- School of Life Sciences, University of Warwick, Coventry, UK
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25
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Bartfai T, Conti B. Molecules affecting hypothalamic control of core body temperature in response to calorie intake. Front Genet 2012; 3:184. [PMID: 23097647 PMCID: PMC3466567 DOI: 10.3389/fgene.2012.00184] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 08/31/2012] [Indexed: 01/07/2023] Open
Abstract
Core body temperature (CBT) and calorie intake are main components of energy homeostasis and two important regulators of health, longevity, and aging. In homeotherms, CBT can be influenced by calorie intake as food deprivation or calorie restriction (CR) lowers CBT whereas feeding has hyperthermic effects. The finding that in mice CBT prolonged lifespan independently of CR, suggested that the mechanisms modulating CBT may represent important regulators of aging. Here we summarize the current knowledge on the signaling molecules and their receptors that participate in the regulation of CBT responses to calorie intake. These include hypothalamic neuropeptides regulating feeding but also energy expenditure via modulation of thermogenesis. We also report studies indicating that nutrient signals can contribute to regulation of CBT by direct action on hypothalamic preoptic warm-sensitive neurons that in turn regulate adaptive thermogenesis and hence CBT. Finally, we show the role played by two orphans G protein-coupled receptor: GPR50 and GPR83, that were recently demonstrated to regulate temperature-dependent energy expenditure.
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Affiliation(s)
- Tamas Bartfai
- Department of Chemical Physiology, The Scripps Research Institute La Jolla, CA, USA
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26
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Grünewald E, Tew KD, Porteous DJ, Thomson PA. Developmental expression of orphan G protein-coupled receptor 50 in the mouse brain. ACS Chem Neurosci 2012; 3:459-72. [PMID: 22860215 DOI: 10.1021/cn300008p] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 04/14/2012] [Indexed: 01/15/2023] Open
Abstract
Mental disorders have a complex etiology resulting from interactions between multiple genetic risk factors and stressful life events. Orphan G protein-coupled receptor 50 (GPR50) has been identified as a genetic risk factor for bipolar disorder and major depression in women, and there is additional genetic and functional evidence linking GPR50 to neurite outgrowth, lipid metabolism, and adaptive thermogenesis and torpor. However, in the absence of a ligand, a specific function has not been identified. Adult GPR50 expression has previously been reported in brain regions controlling the HPA axis, but its developmental expression is unknown. In this study, we performed extensive expression analysis of GPR50 and three protein interactors using rt-PCR and immunohistochemistry in the developing and adult mouse brain. Gpr50 is expressed at embryonic day 13 (E13), peaks at E18, and is predominantly expressed by neurons. Additionally we identified novel regions of Gpr50 expression, including brain stem nuclei involved in neurotransmitter signaling: the locus coeruleus, substantia nigra, and raphe nuclei, as well as nuclei involved in metabolic homeostasis. Gpr50 colocalizes with yeast-two-hybrid interactors Nogo-A, Abca2, and Cdh8 in the hypothalamus, amygdala, cortex, and selected brain stem nuclei at E18 and in the adult. With this study, we identify a link between GPR50 and neurotransmitter signaling and strengthen a likely role in stress response and energy homeostasis.
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Affiliation(s)
- Ellen Grünewald
- Medical Genetics Section, The University of Edinburgh, Institute of Genetics and Molecular Medicine, Molecular Medicine Centre, Crewe Road, Edinburgh EH2 4XU, United Kingdom
| | - Kenneth D. Tew
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - David J. Porteous
- Medical Genetics Section, The University of Edinburgh, Institute of Genetics and Molecular Medicine, Molecular Medicine Centre, Crewe Road, Edinburgh EH2 4XU, United Kingdom
| | - Pippa A. Thomson
- Medical Genetics Section, The University of Edinburgh, Institute of Genetics and Molecular Medicine, Molecular Medicine Centre, Crewe Road, Edinburgh EH2 4XU, United Kingdom
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