1
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Hawker P, Zhang L, Liu L. Mas-related G protein-coupled receptors in gastrointestinal dysfunction and inflammatory bowel disease: A review. Br J Pharmacol 2024; 181:2197-2211. [PMID: 36787888 DOI: 10.1111/bph.16059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/25/2022] [Accepted: 02/04/2023] [Indexed: 02/16/2023] Open
Abstract
Inflammatory bowel disease (IBD) is a chronic debilitating condition, hallmarked by persistent inflammation of the gastrointestinal tract. Despite recent advances in clinical treatments, the aetiology of IBD is unknown, and a large proportion of patients are refractory to pharmacotherapy. Understanding IBD immunopathogenesis is crucial to discern the cause of IBD and optimise treatments. Mas-related G protein-coupled receptors (Mrgprs) are a family of approximately 50 G protein-coupled receptors that were first identified over 20 years ago. Originally known for their expression in skin nociceptors and their role in transmitting the sensation of itch in the periphery, new reports have described the presence of Mrgprs in the gastrointestinal tract. In this review, we consider the impact of these findings and assess the evidence that suggests that Mrgprs may be involved in the disrupted homeostatic processes that contribute to gastrointestinal disorders and IBD. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
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Affiliation(s)
- Patrick Hawker
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Li Zhang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Lu Liu
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
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2
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Van Remoortel S, Lambeets L, De Schepper H, Timmermans JP. The orphan MRGPRF receptor is expressed in entero-endocrine cells of the human gut mucosa. Cell Tissue Res 2023:10.1007/s00441-023-03797-z. [PMID: 37314493 DOI: 10.1007/s00441-023-03797-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 06/05/2023] [Indexed: 06/15/2023]
Abstract
In the past years, it has become clear that the family of Mas-related G protein-coupled receptors plays a central role in neuro-immune communication at mucosal barrier surfaces, in particular in the skin. Remarkably, MRGPR expression at other mucosal surfaces remains poorly characterized. To fill this gap in our understanding, the present study was undertaken to screen and verify the expression of the human MRGPR family members in the mucosal biopsies of the human gastrointestinal (GI) tract. Our findings revealed that, of all human MRGPRs family members, only MRGPRF mRNA is expressed at detectable levels in human mucosal biopsies of both terminal ileum and sigmoid colon. Furthermore, immunohistochemical stainings revealed that MRGPRF is specifically expressed by mucosal entero-endocrine cells (EECs). Overall, this study showed for the first time that the human ileum and colonic mucosa represent a novel expression site for the orphan MRGPRF, more specifically in EECs.
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Affiliation(s)
- Samuel Van Remoortel
- Laboratory of Cell Biology & Histology, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Antwerp, Belgium
| | - Lana Lambeets
- Laboratory of Cell Biology & Histology, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Antwerp, Belgium
| | - Heiko De Schepper
- Department of Gastroenterology and Hepatology, Antwerp University Hospital, Antwerp, Belgium
| | - Jean-Pierre Timmermans
- Laboratory of Cell Biology & Histology, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Antwerp, Belgium.
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3
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Van Remoortel S, Lambeets L, Timmermans JP. Neuro-immune interactions and the role of Mas-related G protein-coupled receptors in the gastrointestinal tract. Anat Rec (Hoboken) 2022; 306:1131-1139. [PMID: 35694864 DOI: 10.1002/ar.25008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/11/2022] [Accepted: 05/20/2022] [Indexed: 11/10/2022]
Abstract
Over the past decade, the research field dealing with the role of a new family of Rhodopsin A-like G protein-coupled receptors, that is, the family of Mas-related G protein-coupled receptors (Mrgprs) has expanded enormously. A plethora of recent studies have provided evidence that Mrgprs are key players in itch and pain, as well as in the initiation and modulation of inflammatory/allergic responses in the skin. Over the years, it has become clear that this role is not limited to the skin, but extends to other mucosal surfaces such as the respiratory tract and the gastrointestinal (GI) tract. In the GI tract, Mrgprs have emerged as novel interoceptive sensory pathways linked to health and disease, and are in close functional association with the gut's immune system. This review aims to provide an update of our current knowledge on the expression, distribution and function of members of this Mrgpr family in intrinsic and extrinsic neuro-immune pathways related to the GI system.
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Affiliation(s)
- Samuel Van Remoortel
- Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
| | - Lana Lambeets
- Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
| | - Jean-Pierre Timmermans
- Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
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4
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Inclan-Rico JM, Rossi HL, Herbert DR. "Every cell is an immune cell; contributions of non-hematopoietic cells to anti-helminth immunity". Mucosal Immunol 2022; 15:1199-1211. [PMID: 35538230 PMCID: PMC9646929 DOI: 10.1038/s41385-022-00518-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/04/2022] [Accepted: 04/19/2022] [Indexed: 02/04/2023]
Abstract
Helminths are remarkably successful parasites that can invade various mammalian hosts and establish chronic infections that can go unnoticed for years despite causing severe tissue damage. To complete their life cycles, helminths migrate through multiple barrier sites that are densely populated by a complex array of hematopoietic and non-hematopoietic cells. While it is clear that type 2 cytokine responses elicited by immune cells promote worm clearance and tissue healing, the actions of non-hematopoietic cells are increasingly recognized as initiators, effectors and regulators of anti-helminth immunity. This review will highlight the collective actions of specialized epithelial cells, stromal niches, stem, muscle and neuroendocrine cells as well as peripheral neurons in the detection and elimination of helminths at mucosal sites. Studies dissecting the interactions between immune and non-hematopoietic cells will truly provide a better understanding of the mechanisms that ensure homeostasis in the context of helminth infections.
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Affiliation(s)
- Juan M Inclan-Rico
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Heather L Rossi
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - De'Broski R Herbert
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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5
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Keely SJ, Urso A, Ilyaskin AV, Korbmacher C, Bunnett NW, Poole DP, Carbone SE. Contributions of bile acids to gastrointestinal physiology as receptor agonists and modifiers of ion channels. Am J Physiol Gastrointest Liver Physiol 2022; 322:G201-G222. [PMID: 34755536 PMCID: PMC8782647 DOI: 10.1152/ajpgi.00125.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 10/28/2021] [Accepted: 11/08/2021] [Indexed: 02/03/2023]
Abstract
Bile acids (BAs) are known to be important regulators of intestinal motility and epithelial fluid and electrolyte transport. Over the past two decades, significant advances in identifying and characterizing the receptors, transporters, and ion channels targeted by BAs have led to exciting new insights into the molecular mechanisms involved in these processes. Our appreciation of BAs, their receptors, and BA-modulated ion channels as potential targets for the development of new approaches to treat intestinal motility and transport disorders is increasing. In the current review, we aim to summarize recent advances in our knowledge of the different BA receptors and BA-modulated ion channels present in the gastrointestinal system. We discuss how they regulate motility and epithelial transport, their roles in pathogenesis, and their therapeutic potential in a range of gastrointestinal diseases.
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Affiliation(s)
- Stephen J Keely
- Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Andreacarola Urso
- Department of Surgery, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York
- Department of Pharmacology, Columbia University, New York, New York
| | - Alexandr V Ilyaskin
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander University Erlangen-Nürnberg, Bavaria, Germany
| | - Christoph Korbmacher
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander University Erlangen-Nürnberg, Bavaria, Germany
| | - Nigel W Bunnett
- Department of Molecular Pathobiology, Neuroscience Institute, New York University, New York, New York
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University, New York, New York
| | - Daniel P Poole
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council, Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Simona E Carbone
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Australian Research Council, Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
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6
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Mas-Related G Protein-Coupled Receptors (Mrgprs) as Mediators of Gut Neuro-Immune Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:259-269. [PMID: 36587165 DOI: 10.1007/978-3-031-05843-1_25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Over the past 15 years, the research field on Mas-related G protein-coupled receptors (Mrgprs), a relatively new family of rhodopsin A-like G protein-coupled receptors, has expanded enormously, and a plethora of recent studies have provided evidence that several of these Mrgpr family members play an important role in the underlying mechanisms of itch and pain, as well as in the initiation and modulation of inflammatory/allergic responses. Initial studies mainly focused on the skin, but more recently also visceral organs such as the respiratory and gastrointestinal (GI) tracts emerged as sites for Mrgpr involvement. It has become clear that the gastrointestinal tract and its innervation in close association with the immune system represent a novel expression site for Mrgprs where they contribute to the interoceptive mechanisms maintaining homeostasis and might constitute promising targets in chronic abdominal pain disorders. In this short review, we provide an update of our current knowledge on the expression, distribution, and function of members of this Mrgpr family in intrinsic and extrinsic neuro-immune pathways related to the gastrointestinal tract, their mediatory role(s) in gut neuro-immune signaling, and their involvement in visceral afferent (nociceptive) pathways.
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7
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Brizuela M, Castro J, Harrington AM, Brierley SM. Pruritogenic mechanisms and gut sensation: putting the "irritant" into irritable bowel syndrome. Am J Physiol Gastrointest Liver Physiol 2021; 320:G1131-G1141. [PMID: 33949199 DOI: 10.1152/ajpgi.00331.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Chronic abdominal pain is a common clinical condition experienced by patients with irritable bowel syndrome (IBS). A general lack of suitable treatment options for the management of visceral pain is the major contributing factor to the debilitating nature of the disease. Understanding the underlying causes of chronic visceral pain is pivotal to identifying new effective therapies for IBS. This review provides the current evidence, demonstrating that mediators and receptors that induce itch in the skin also act as "gut irritants" in the gastrointestinal tract. Activation of these receptors triggers specific changes in the neuronal excitability of sensory pathways responsible for the transmission of nociceptive information from the periphery to the central nervous system leading to visceral hypersensitivity and visceral pain. Accumulating evidence points to significant roles of irritant mediators and their receptors in visceral hypersensitivity and thus constitutes potential targets for the development of more effective therapeutic options for IBS.
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Affiliation(s)
- Mariana Brizuela
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Joel Castro
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Andrea M Harrington
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Stuart M Brierley
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia
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8
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Serhan N, Cenac N, Basso L, Gaudenzio N. Mas-related G protein-coupled receptors (Mrgprs) - Key regulators of neuroimmune interactions. Neurosci Lett 2021; 749:135724. [PMID: 33600909 DOI: 10.1016/j.neulet.2021.135724] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 02/06/2023]
Abstract
Interplay between physiological systems in the body plays a prominent role in health and disease. At the cellular level, such interplay is orchestrated through the binding of specific ligands to their receptors expressed on cell surface. G protein-coupled receptors (GPCR) are seven-transmembrane domain receptors that initiate various cellular responses and regulate homeostasis. In this review, we focus on particular GPCRs named Mas-related G protein-coupled receptors (Mrgprs) mainly expressed by sensory neurons and specialized immune cells. We describe the different subfamilies of Mrgprs and their specific ligands, as well as recent advances in the field that illustrate the role played by these receptors in neuro-immune biological processes, including itch, pain and inflammation in diverse organs.
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Affiliation(s)
- Nadine Serhan
- Toulouse Institute for Infectious and Inflammatory Diseases, INSERM UMR1291, CNRS UMR5051, University of Toulouse III, Toulouse, France
| | - Nicolas Cenac
- IRSD, Université de Toulouse, INSERM, INRA, INP-ENVT, Université de Toulouse 3 Paul Sabatier, Toulouse, France
| | - Lilian Basso
- Toulouse Institute for Infectious and Inflammatory Diseases, INSERM UMR1291, CNRS UMR5051, University of Toulouse III, Toulouse, France.
| | - Nicolas Gaudenzio
- Toulouse Institute for Infectious and Inflammatory Diseases, INSERM UMR1291, CNRS UMR5051, University of Toulouse III, Toulouse, France.
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9
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Inclan-Rico JM, Kim BS, Abdus-Saboor I. Beyond somatosensation: Mrgprs in mucosal tissues. Neurosci Lett 2021; 748:135689. [PMID: 33582191 DOI: 10.1016/j.neulet.2021.135689] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/11/2021] [Accepted: 01/19/2021] [Indexed: 11/29/2022]
Abstract
Mas-related G coupled receptors (Mrgprs) are a superfamily of receptors expressed in sensory neurons that are known to transmit somatic sensations from the skin to the central nervous system. Interestingly, Mrgprs have recently been implicated in sensory and motor functions of mucosal-associated neuronal circuits. The gastrointestinal and pulmonary tracts are constantly exposed to noxious stimuli. Therefore, it is likely that neuronal Mrgpr signaling pathways in mucosal tissues, akin to their family members expressed in the skin, might relay messages that alert the host when mucosal tissues are affected by damaging signals. Further, Mrgprs have been proposed to mediate the cross-talk between sensory neurons and immune cells that promotes host-protective functions at barrier sites. Although the mechanisms by which Mrgprs are activated in mucosal tissues are not completely understood, these exciting studies implicate Mrgprs as potential therapeutic targets for conditions affecting the intestinal and airway mucosa. This review will highlight the central role of Mrgpr signaling pathways in the regulation of homeostasis at mucosal tissues.
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Affiliation(s)
- Juan M Inclan-Rico
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - Brian S Kim
- Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA; Center for the Study of Itch and Sensory Disorders, Washington University School of Medicine, St. Louis, MO, USA.
| | - Ishmail Abdus-Saboor
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA.
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10
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Corbière A, Loste A, Gaudenzio N. MRGPRX2 sensing of cationic compounds-A bridge between nociception and skin diseases? Exp Dermatol 2020; 30:193-200. [PMID: 33107136 DOI: 10.1111/exd.14222] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/11/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023]
Abstract
Mast cells are innate immune cells located at many barrier sites in the body and known to protect the host against environmental threats and to be involved in allergic diseases. More recently, new studies have investigated their roles in the regulation of skin inflammation and transmission of pain and itch sensations. Mast cell signalling through the Mas-related G protein-coupled receptor (MRGPR) X2 or its mouse orthologue MRGPRB2 has been reported to be one of the major mechanism by which mast cell can regulate such processes. MRGPRX2 and MRGPRB2 can induce mast cell degranulation upon binding to a broad panel of cationic molecules such as neuropeptides, bacteria-derived quorum sensing molecules, venom peptides, host defense peptides and, unfortunately, various FDA-approved drugs. Upon activation, mast cells release granule-associated proteases, lipids and multiple cytokines that can modulate vascular permeability, immune cells recruitment and activation status of tissue-projecting nociceptive sensory neurons (ie nociceptors). Here, we discuss the modality of MRGPRX2-dependent mast cell activation and its different consequences on the patterns of skin inflammation and associated diseases. We notably emphasize how MRGPRX2-dependent skin mast cell activation might trigger various pathological traits such as pruritus, pain and inflammation and therefore become a potential therapeutic target for inflammatory pain, itch, atopic dermatitis and drugs-induced injection site reactions.
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Affiliation(s)
- Auriane Corbière
- Unité de Différenciation Epithéliale et Autoimmunité Rhumatoïde, UMR 1056, INSERM, Université de Toulouse, Toulouse, France
| | - Alexia Loste
- Unité de Différenciation Epithéliale et Autoimmunité Rhumatoïde, UMR 1056, INSERM, Université de Toulouse, Toulouse, France
| | - Nicolas Gaudenzio
- Unité de Différenciation Epithéliale et Autoimmunité Rhumatoïde, UMR 1056, INSERM, Université de Toulouse, Toulouse, France
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11
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Hamamura-Yasuno E, Iguchi T, Kumagai K, Tsuchiya Y, Mori K. Identification of the dog orthologue of human MAS-related G protein coupled receptor X2 (MRGPRX2) essential for drug-induced pseudo-allergic reactions. Sci Rep 2020; 10:16146. [PMID: 32999394 PMCID: PMC7527510 DOI: 10.1038/s41598-020-72819-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/07/2020] [Indexed: 12/03/2022] Open
Abstract
MAS-related G protein coupled receptor-X2 (MRGPRX2), expressed in human mast cells, is associated with drug-induced pseudo-allergic reactions. Dogs are highly susceptible to drug-induced anaphylactoid reactions caused by various drugs; however, the distribution and physiological function of canine MRGPR family genes, including MRGPRX2, remain largely unknown. In the present study, we clarified the distribution of dog MRGPR family genes by real-time quantitative PCR and in situ hybridisation. We also investigated the stimulatory effects of various histamine-releasing agents, including fluoroquinolones, on HEK293 cells transiently transfected with dog MRGPR family genes to identify their physiological function. Dog MRGPRX2 and MRGPRG were distributed in a limited number of tissues, including the skin (from the eyelid, abdomen, and cheek), whereas MRGPRD and MRGPRF were extensively expressed in almost all tissues examined. Histochemical and in situ hybridisation analyses revealed that MRGPRX2 was expressed in dog connective tissue-type mast cells in the skin. Intracellular Ca2+ mobilisation assay revealed that HEK293 cells, expressing dog MRGPRX2 or human MRGPRX2, but not dog MRGPRD, MRGPRF, and MRGPRG, responded to histamine-releasing agents. Our results suggest that dog MRGPRX2 is the functional orthologue of human MRGPRX2 and plays an essential role in drug-induced anaphylactoid reactions in dogs.
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Affiliation(s)
- Eri Hamamura-Yasuno
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kitakasai, Edogawa-ku, Tokyo, 134-8630, Japan.
| | - Takuma Iguchi
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kitakasai, Edogawa-ku, Tokyo, 134-8630, Japan
| | - Kazuyoshi Kumagai
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kitakasai, Edogawa-ku, Tokyo, 134-8630, Japan
| | - Yoshimi Tsuchiya
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kitakasai, Edogawa-ku, Tokyo, 134-8630, Japan
| | - Kazuhiko Mori
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13 Kitakasai, Edogawa-ku, Tokyo, 134-8630, Japan
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12
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Presence of MrgprD within the gastrointestinal wall: reality or fake? Cell Tissue Res 2019; 378:555-558. [PMID: 31473818 DOI: 10.1007/s00441-019-03097-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 08/13/2019] [Indexed: 01/16/2023]
Abstract
Due to their pivotal role in nociception and mast cell biology, the family of Mas-related G protein-coupled receptors (Mrgprs) has recently gained attention for their possible expression and role(s) in the gastrointestinal tract. In this context, based on immunocytochemical stainings using a commercial antibody, a recent study by Zhou et al. reported that the murine Mrgprd member is expressed in mouse gut lamina propria immune cells and in the outer smooth muscle layers pointing to a potential role for MrgprD in inflammatory responses and intestinal immunity. Immunohistochemical staining for G protein-coupled receptors (GPCRs), however, remains challenging and should be cautiously interpreted using appropriate specificity controls. Using the same antibody with an identical dilution, we did observe a similar staining in the same wild-type mouse strain, but an identical staining pattern was also found in mice lacking the MrgprD receptor, indicating that this antibody recognizes epitopes other than those of MrgprD. Moreover, in situ hybridization for MrgprD further indicated the absence of receptor mRNA expression in lamina propria immune cells and in the outer smooth muscle layers. Therefore, the results and conclusions regarding the presence of MrgprD at protein level within the GI wall as described in the study of Zhou and collaborators should be interpreted with strong caution and should be reconsidered in the light of the emerging possible roles of MrgprD and therapeutic perspectives in gastrointestinal pathophysiology.
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13
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Zhou C, Li J, Liu L, Tang Z, Wan F, Lan L. Expression and localization of MrgprD in mouse intestinal tract. Cell Tissue Res 2019; 377:259-268. [PMID: 30919047 PMCID: PMC6647478 DOI: 10.1007/s00441-019-03017-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 03/09/2019] [Indexed: 12/16/2022]
Abstract
MrgprD, a Mas-related G protein-coupled receptor, is initially identified in sensory neurons of mouse dorsal root ganglia (DRG) and has been suggested to participate in somatosensation. However, MrgprD has recently been found to be expressed outside the nervous system such as in aortic endothelia cells and neutrophils. In this study, we used immunohistochemistry to detect the expression and localization of MrgprD in mouse intestinal tract. The immunoreactivity (IR) of MrgprD was found in the smooth muscle layers of small intestine, colon and rectum. In addition, MrgprD IR was colocalized with F4/80-positive macrophages and CD3-positive T lymphocytes resident in the lamina propria of intestinal mucosa. MrgprD was also found to be expressed in primary peritoneal macrophages and splenic T lymphocytes. Furthermore, the presence of MrgprD mRNA and its protein was detected in murine macrophage-like RAW 264.7 and human T lymphocyte Jurkat cell lines. Our study shows, for the first time, the expression and localization of MrgprD in the intestinal tract and in macrophages and T lymphocytes, indicating the potential roles of MrgprD in intestinal mobility and immunity.
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Affiliation(s)
- Chenxing Zhou
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023 Jiangsu People’s Republic of China
| | - Jia Li
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023 Jiangsu People’s Republic of China
| | - Lin Liu
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023 Jiangsu People’s Republic of China
| | - Zongxiang Tang
- Key Laboratory of Chinese Medicine for Prevention and Treatment of Neurological Diseases, School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, 210023 Jiangsu People’s Republic of China
| | - Fengyi Wan
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205 USA
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205 USA
- Department of Oncology and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD 21205 USA
| | - Lei Lan
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023 Jiangsu People’s Republic of China
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14
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Schleifenbaum J. Alamandine and Its Receptor MrgD Pair Up to Join the Protective Arm of the Renin-Angiotensin System. Front Med (Lausanne) 2019; 6:107. [PMID: 31245374 PMCID: PMC6579891 DOI: 10.3389/fmed.2019.00107] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/30/2019] [Indexed: 11/18/2022] Open
Abstract
Only a few years ago, alamandine was found to be a member of the protective arm of the renin-angiotensin system. It turned out to be an endogenous ligand of the G protein-coupled receptor MrgD. So far, MrgD had predominantly been studied in a neuronal context. The expression of the receptor in non-neuronal tissue showed hitherto unknown effects mediated by MrgD, most strikingly alamandine-induced vasodilation. Alamandine being a part of the non-classical renin-angiotensin system, a protective role of receptor activation seemed natural. This review summarizes the different effects of MrgD activation by alamandine in vasculature, in the central nervous system, and in organs as kidney and heart. Alamandine and MrgD are promising novel drug targets to protect the kidney and heart through anti-hypertensive actions.
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Affiliation(s)
- Johanna Schleifenbaum
- Institute of Vegetative Physiology, Berlin Institute of Health, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
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Abstract
Chronic, persistent itch is a devastating symptom that causes much suffering. In recent years, there has been great progress made in understanding the molecules, cells, and circuits underlying itch sensation. Once thought to be carried by pain-sensing neurons, itch is now believed to be capable of being transmitted by dedicated sensory labeled lines. Members of the Mas-related G protein-coupled receptor (Mrgpr) family demarcate an itch-specific labeled line in the peripheral nervous system. In the spinal cord, the expression of other proteins identifies additional populations of itch-dedicated sensory neurons. However, as evidence for labeled-line coding has mounted, studies promoting alternative itch-coding strategies have emerged, complicating our understanding of the neural basis of itch. In this review, we cover the molecules, cells, and circuits related to understanding the neural basis of itch, with a focus on the role of Mrgprs in mediating itch sensation.
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Affiliation(s)
- James Meixiong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21205, USA; ,
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21205, USA; , .,Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Peiris M, Hockley JR, Reed DE, Smith ESJ, Bulmer DC, Blackshaw LA. Peripheral K V7 channels regulate visceral sensory function in mouse and human colon. Mol Pain 2018; 13:1744806917709371. [PMID: 28566000 PMCID: PMC5456027 DOI: 10.1177/1744806917709371] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background Chronic visceral pain is a defining symptom of many gastrointestinal disorders. The KV7 family (KV7.1–KV7.5) of voltage-gated potassium channels mediates the M current that regulates excitability in peripheral sensory nociceptors and central pain pathways. Here, we use a combination of immunohistochemistry, gut-nerve electrophysiological recordings in both mouse and human tissues, and single-cell qualitative real-time polymerase chain reaction of gut-projecting sensory neurons, to investigate the contribution of peripheral KV7 channels to visceral nociception. Results Immunohistochemical staining of mouse colon revealed labelling of KV7 subtypes (KV7.3 and KV7.5) with CGRP around intrinsic enteric neurons of the myenteric plexuses and within extrinsic sensory fibres along mesenteric blood vessels. Treatment with the KV7 opener retigabine almost completely abolished visceral afferent firing evoked by the algogen bradykinin, in agreement with significant co-expression of mRNA transcripts by single-cell qualitative real-time polymerase chain reaction for KCNQ subtypes and the B2 bradykinin receptor in retrogradely labelled extrinsic sensory neurons from the colon. Retigabine also attenuated responses to mechanical stimulation of the bowel following noxious distension (0–80 mmHg) in a concentration-dependent manner, whereas the KV7 blocker XE991 potentiated such responses. In human bowel tissues, KV7.3 and KV7.5 were expressed in neuronal varicosities co-labelled with synaptophysin and CGRP, and retigabine inhibited bradykinin-induced afferent activation in afferent recordings from human colon. Conclusions We show that KV7 channels contribute to the sensitivity of visceral sensory neurons to noxious chemical and mechanical stimuli in both mouse and human gut tissues. As such, peripherally restricted KV7 openers may represent a viable therapeutic modality for the treatment of gastrointestinal pathologies.
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Affiliation(s)
- Madusha Peiris
- 1 Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - James Rf Hockley
- 2 Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - David E Reed
- 3 GI Diseases Research Unit, Queen's University, Kingston, ON, Canada
| | | | - David C Bulmer
- 1 Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - L Ashley Blackshaw
- 1 Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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Buckinx R, Van Remoortel S, Gijsbers R, Waddington SN, Timmermans JP. Proof-of-concept: neonatal intravenous injection of adeno-associated virus vectors results in successful transduction of myenteric and submucosal neurons in the mouse small and large intestine. Neurogastroenterol Motil 2016; 28:299-305. [PMID: 26564813 DOI: 10.1111/nmo.12724] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 10/11/2015] [Indexed: 12/20/2022]
Abstract
BACKGROUND Despite the success of viral vector technology in the transduction of the central nervous system in both preclinical research and gene therapy, its potential in neurogastroenterological research remains largely unexploited. This study asked whether and to what extent myenteric and submucosal neurons in the ileum and distal colon of the mouse were transduced after neonatal systemic delivery of recombinant adeno-associated viral vectors (AAVs). METHODS Mice were intravenously injected at postnatal day one with AAV pseudotypes AAV8 or AAV9 carrying a cassette encoding enhanced green fluorescent protein (eGFP) as a reporter under the control of a cytomegalovirus promoter. At postnatal day 35, transduction of the myenteric and submucosal plexuses of the ileum and distal colon was evaluated in whole-mount preparations, using immunohistochemistry to neurochemically identify transduced enteric neurons. KEY RESULTS The pseudotypes AAV8 and AAV9 showed equal potential in transducing the enteric nervous system (ENS), with 25-30% of the neurons expressing eGFP. However, the percentage of eGFP-expressing colonic submucosal neurons was significantly lower. Neurochemical analysis showed that all enteric neuron subtypes, but not glia, expressed the reporter protein. Intrinsic sensory neurons were most efficiently transduced as nearly 80% of calcitonin gene-related peptide-positive neurons expressed the transgene. CONCLUSIONS & INFERENCES The pseudotypes AAV8 and AAV9 can be employed for gene delivery to both the myenteric and the submucosal plexus, although the transduction efficiency in the latter is region-dependent. These findings open perspectives for novel preclinical applications aimed at manipulating and imaging the ENS in the short term, and in gene therapy in the longer term.
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Affiliation(s)
- R Buckinx
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - S Van Remoortel
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - R Gijsbers
- Laboratory for Viral Vector Technology & Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.,Leuven Viral Vector Core, KU Leuven, Leuven, Belgium
| | - S N Waddington
- Gene Transfer Technology Group, Institute for Women's Health, University College London, London, UK.,Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - J-P Timmermans
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
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Alpaerts K, Buckinx R, Cools N, Heylen M, Nullens S, Berneman Z, De Winter B, Adriaensen D, Van Nassauw L, Timmermans JP. Effect of schistosomiasis on CX3CR1-expressing mononuclear phagocytes in the ileum and mesenteric lymph nodes of the mouse. Neurogastroenterol Motil 2015; 27:1587-99. [PMID: 26303459 DOI: 10.1111/nmo.12658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 07/22/2015] [Indexed: 01/25/2023]
Abstract
BACKGROUND Intestinal dendritic cells (DCs) maintain immune homeostasis, only initiating an active immune response against invading pathogens. However, little information is available on the reaction of mononuclear phagocytes (MNP) to intestinal trematode infection, a reaction equally important in helminth-based therapies. The CD11c(+) CX3CR1(+) F4/80(-) DCs in the ileal lamina propria (LP) of the mouse were proven to migrate to the mesenteric lymph nodes (MLNs). We analyzed all MNP subsets present in the mouse LP and MLNs, under steady-state conditions and during acute Schistosoma mansoni-induced inflammation. Furthermore, we studied the uptake of schistosomal antigens by MNP in vivo in the LP and MLNs. METHODS Using a combination of immunohistochemistry and multiparametric flow cytometry, we investigated distributional changes of the MNP during acute intestinal schistosomiasis. Next, S. mansoni-derived products, i.e., S. mansoni soluble worm proteins (SmSWP) and S. mansoni soluble egg antigens (SmSEA) were intraperitoneally injected into CX3CR1(+/) (GFP) C57BL/6 mice and antigen uptake was analyzed using confocal microscopy. KEY RESULTS The CD11c(+) CX3CR1(+) F4/80(-) DCs significantly increased during intestinal schistosomiasis in the LP and MLNs. Only CX3CR1-expressing DC and MФ subsets, but not other LP DCs, are involved in both SmSWP and SmSEA antigen uptake and processing. CONCLUSIONS & INFERENCES The significant upregulation of CD11c(+) CX3CR1(+) F4/80(-) DCs during intestinal schistosomiasis and the restriction of phagocytosis of parasitic antigens to CX3CR1-expresssing MNP indicate a crucial role for this immune cell niche in response to trematodiasis. These findings add insight into the functional specialization of LP immune cells and add to the understanding of cellular mechanisms behind helminth-based therapies.
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Affiliation(s)
- K Alpaerts
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - R Buckinx
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - N Cools
- Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp University Hospital (UZA), Edegem, Belgium
| | - M Heylen
- Laboratory of Experimental Medicine and Pediatrics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - S Nullens
- Laboratory of Experimental Medicine and Pediatrics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Z Berneman
- Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp University Hospital (UZA), Edegem, Belgium.,Center for Cell Therapy and Regenerative Medicine, Antwerp University Hospital (UZA), Edegem, Belgium
| | - B De Winter
- Laboratory of Experimental Medicine and Pediatrics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - D Adriaensen
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - L Van Nassauw
- Laboratory of Human Anatomy and Embryology, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - J-P Timmermans
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
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Bader M, Alenina N, Andrade-Navarro MA, Santos RA. MAS and its related G protein-coupled receptors, Mrgprs. Pharmacol Rev 2015; 66:1080-105. [PMID: 25244929 DOI: 10.1124/pr.113.008136] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The Mas-related G protein-coupled receptors (Mrgprs or Mas-related genes) comprise a subfamily of receptors named after the first discovered member, Mas. For most Mrgprs, pruriception seems to be the major function based on the following observations: 1) they are relatively promiscuous in their ligand specificity with best affinities for itch-inducing substances; 2) they are expressed in sensory neurons and mast cells in the skin, the main cellular components of pruriception; and 3) they appear in evolution first in tetrapods, which have arms and legs necessary for scratching to remove parasites or other noxious substances from the skin before they create harm. Because parasites coevolved with hosts, each species faced different parasitic challenges, which may explain another striking observation, the multiple independent duplication and expansion events of Mrgpr genes in different species as a consequence of parallel adaptive evolution. Their predominant expression in dorsal root ganglia anticipates additional functions of Mrgprs in nociception. Some Mrgprs have endogenous ligands, such as β-alanine, alamandine, adenine, RF-amide peptides, or salusin-β. However, because the functions of these agonists are still elusive, the physiologic role of the respective Mrgprs needs to be clarified. The best studied Mrgpr is Mas itself. It was shown to be a receptor for angiotensin-1-7 and to exert mainly protective actions in cardiovascular and metabolic diseases. This review summarizes the current knowledge about Mrgprs, their evolution, their ligands, their possible physiologic functions, and their therapeutic potential.
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Affiliation(s)
- Michael Bader
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany (M.B., N.A., M.A.A.-N.); Charité-University Medicine, Berlin, Germany (M.B.); Institute for Biology, University of Lübeck, Lübeck, Germany (M.B.); and Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil (M.B., N.A., R.A.S.)
| | - Natalia Alenina
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany (M.B., N.A., M.A.A.-N.); Charité-University Medicine, Berlin, Germany (M.B.); Institute for Biology, University of Lübeck, Lübeck, Germany (M.B.); and Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil (M.B., N.A., R.A.S.)
| | - Miguel A Andrade-Navarro
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany (M.B., N.A., M.A.A.-N.); Charité-University Medicine, Berlin, Germany (M.B.); Institute for Biology, University of Lübeck, Lübeck, Germany (M.B.); and Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil (M.B., N.A., R.A.S.)
| | - Robson A Santos
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany (M.B., N.A., M.A.A.-N.); Charité-University Medicine, Berlin, Germany (M.B.); Institute for Biology, University of Lübeck, Lübeck, Germany (M.B.); and Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil (M.B., N.A., R.A.S.)
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20
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Solinski HJ, Gudermann T, Breit A. Pharmacology and signaling of MAS-related G protein-coupled receptors. Pharmacol Rev 2015; 66:570-97. [PMID: 24867890 DOI: 10.1124/pr.113.008425] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Signaling by heptahelical G protein-coupled receptors (GPCR) regulates many vital body functions. Consequently, dysfunction of GPCR signaling leads to pathologic states, and approximately 30% of all modern clinical drugs target GPCR. One decade ago, an entire new GPCR family was discovered, which was recently named MAS-related G protein-coupled receptors (MRGPR) by the HUGO Gene Nomenclature Committee. The MRGPR family consists of ∼40 members that are grouped into nine distinct subfamilies (MRGPRA to -H and -X) and are predominantly expressed in primary sensory neurons and mast cells. All members are formally still considered "orphan" by the Committee on Receptor Nomenclature and Drug Classification of the International Union of Basic and Clinical Pharmacology. However, several distinct peptides and amino acids are discussed as potential ligands, including β-alanine, angiotensin-(1-7), alamandine, GABA, cortistatin-14, and cleavage products of proenkephalin, pro-opiomelanocortin, prodynorphin, or proneuropeptide-FF-A. The full spectrum of biologic roles of all MRGPR is still ill-defined, but there is evidence pointing to a role of distinct MRGPR subtypes in nociception, pruritus, sleep, cell proliferation, circulation, and mast cell degranulation. This review article summarizes findings published in the last 10 years on the phylogenetic relationships, pharmacology, signaling, physiology, and agonist-promoted regulation of all MRGPR subfamilies. Furthermore, we highlight interactions between MRGPR and other hormonal systems, paying particular attention to receptor multimerization and morphine tolerance. Finally, we discuss the challenges the field faces presently and emphasize future directions of research.
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Affiliation(s)
- Hans Jürgen Solinski
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
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21
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Buckinx R, Bagyanszki M, Avula LR, Adriaensen D, Van Nassauw L, Timmermans JP. Expression of corticotropin-releasing factor and urocortins in the normal and Schistosoma mansoni-infected mouse ileum. Cell Tissue Res 2014; 359:453-463. [DOI: 10.1007/s00441-014-2012-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 09/17/2014] [Indexed: 12/31/2022]
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22
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Hohenhaus DM, Schaale K, Le Cao KA, Seow V, Iyer A, Fairlie DP, Sweet MJ. An mRNA atlas of G protein-coupled receptor expression during primary human monocyte/macrophage differentiation and lipopolysaccharide-mediated activation identifies targetable candidate regulators of inflammation. Immunobiology 2013; 218:1345-53. [PMID: 23948647 DOI: 10.1016/j.imbio.2013.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 07/04/2013] [Accepted: 07/06/2013] [Indexed: 12/15/2022]
Abstract
G protein-coupled receptors (GPCRs) are among the most important targets in drug discovery. In this study, we used TaqMan Low Density Arrays to profile the full GPCR repertoire of primary human macrophages differentiated from monocytes using either colony stimulating factor-1 (CSF-1/M-CSF) (CSF-1 Mϕ) or granulocyte macrophage colony stimulating factor (GM-CSF) (GM-CSF Mϕ). The overall trend was a downregulation of GPCRs during monocyte to macrophage differentiation, but a core set of 10 genes (e.g. LGR4, MRGPRF and GPR143) encoding seven transmembrane proteins were upregulated, irrespective of the differentiating agent used. Several of these upregulated GPCRs have not previously been studied in the context of macrophage biology and/or inflammation. As expected, CSF-1 Mϕ and GM-CSF Mϕ exhibited differential inflammatory cytokine profiles in response to the Toll-like Receptor (TLR)4 agonist lipopolysaccharide (LPS). Moreover, 15 GPCRs were differentially expressed between these cell populations in the basal state. For example, EDG1 was expressed at elevated levels in CSF-1 Mϕ versus GM-CSF Mϕ, whereas the reverse was true for EDG6. 101 GPCRs showed differential regulation over an LPS time course, with 65 of these profiles being impacted by the basal differentiation state (e.g. GPRC5A, GPRC5B). Only 14 LPS-regulated GPCRs showed asynchronous behavior (divergent LPS regulation) with respect to differentiation status. Thus, the differentiation state primarily affects the magnitude of LPS-regulated expression, rather than causing major reprogramming of GPCR gene expression profiles. Several GPCRs showing differential profiles between CSF-1 Mϕ and GM-CSF Mϕ (e.g. P2RY8, GPR92, EMR3) have not been widely investigated in macrophage biology and inflammation. Strikingly, several closely related GPCRs displayed completely opposing patterns of regulation during differentiation and/or activation (e.g. EDG1 versus EDG6, LGR4 versus LGR7, GPRC5A versus GPRC5B). We propose that selective regulation of GPCR5A and GPCR5B in CSF-1 Mϕ contributes to skewing toward the M2 macrophage phenotype. Our analysis of the GPCR repertoire expressed during primary human monocyte to macrophage differentiation and TLR4-mediated activation provides a valuable new platform for conducting future functional analyses of individual GPCRs in human macrophage inflammatory pathways.
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Affiliation(s)
- Daniel M Hohenhaus
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld 4072, Australia; Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Qld 4072, Australia
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Expression and distribution patterns of Mas-related gene receptor subtypes A-H in the mouse intestine: inflammation-induced changes. Histochem Cell Biol 2013; 139:639-58. [PMID: 23504129 DOI: 10.1007/s00418-013-1086-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2013] [Indexed: 12/20/2022]
Abstract
Mas-related gene (Mrg) receptors constitute a subfamily of G protein-coupled receptors that are implicated in nociception, and are as such considered potential targets for pain therapies. Furthermore, some Mrgs have been suggested to play roles in the regulation of inflammatory responses to non-immunological activation of mast cells and in mast cell-neuron communication. Except for MrgD, E and F, whose changed expression has been revealed during inflammation in the mouse intestine in our earlier studies, information concerning the remaining cloned mouse Mrg subtypes in the gastrointestinal tract during (patho) physiological conditions is lacking. Therefore, the present study aimed at identifying the presence and putative function of these remaining cloned Mrg subtypes (n = 19) in the (inflamed) mouse intestine. Using reverse transcriptase-PCR, quantitative-PCR and multiple immunofluorescence staining with commercial and newly custom-developed antibodies, we compared the ileum and the related dorsal root ganglia (DRG) of non-inflamed mice with those of two models of intestinal inflammation, i.e., intestinal schistosomiasis and 2,4,6-trinitrobenzene sulfonic acid-induced ileitis. In the non-inflamed ileum and DRG, the majority of the Mrg subtypes examined were sparsely expressed, showing a neuron-specific expression pattern. However, significant changes in the expression patterns of multiple Mrg subtypes were observed in the inflamed ileum; for instance, MrgA4, MrgB2and MrgB8 were expressed in a clearly increased number of enteric sensory neurons and in nerve fibers in the lamina propria, while de novo expression of MrgB10 was observed in enteric sensory neurons and in newly recruited mucosal mast cells (MMCs). The MrgB10 expressing MMCs were found to be in close contact with nerve fibers in the lamina propria. This is the first report on the expression of all cloned Mrg receptor subtypes in the (inflamed) mouse intestine. The observed changes in the expression and cellular localization of the Mrg subtypes suggest that these receptors are involved in the mediation of primary afferent responses, mast cell responses, and in neuroimmune communication during intestinal inflammation.
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Avula LR, Knapen D, Buckinx R, Vergauwen L, Adriaensen D, Van Nassauw L, Timmermans JP. Whole-genome microarray analysis and functional characterization reveal distinct gene expression profiles and patterns in two mouse models of ileal inflammation. BMC Genomics 2012; 13:377. [PMID: 22866923 PMCID: PMC3599598 DOI: 10.1186/1471-2164-13-377] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 07/18/2012] [Indexed: 12/16/2022] Open
Abstract
Background Although a number of intestinal inflammatory conditions pertain to the ileum, whole-genome gene expression analyses in animal models of ileal inflammation are lacking to date. Therefore, we aimed to identify and characterize alterations in gene expression in the acutely inflamed ileum of two murine models of intestinal inflammation, namely intestinal schistosomiasis and TNBS-induced ileitis, compared to healthy controls. To this end, we used whole-genome microarrays, followed by bioinformatics analyses to detect over-represented Kyoto Encyclopedia of Genes and Genomes pathways and Gene Ontology categories. Results Following screening of almost all known mouse genes and transcripts represented on the array, intestinal schistosomiasis and TNBS-induced ileitis yielded 207 and 1417 differentially expressed genes, respectively, with only 30 overlapping concordantly changed genes. Functional category groups consisting of complement and coagulation cascades, extracellular matrix (ECM)-receptor interaction, Fc epsilon receptor I signaling pathways and protein activation cascade, cell adhesion categories were over-represented in the differential gene list of intestinal schistosomiasis. Antigen processing and presentation, cell adhesion molecules, ABC transporters, Toll-like receptor signaling pathways and response to chemical stimulus categories were over-represented in the differential gene list of TNBS-induced ileitis. Although cytokine-cytokine receptor interaction, intestinal immune network for IgA production, focal adhesion pathways and immune, inflammatory and defense response categories were over-represented in the differential gene lists of both inflammation models, the vast majority of the associated genes and changes were unique to each model. Conclusions This study characterized two models of ileal inflammation at a whole-genome level and outlined distinct gene expression profiles and patterns in the two models. The results indicate that intestinal schistosomiasis involves Th2 responses, complement activation, protein activation and enhanced ECM turnover, while TNBS-induced ileitis involves Th17 responses, defective antigen processing and presentation and altered Toll-like receptor-mediated responses. Signs of an impaired epithelial barrier are apparent in both inflammation models. Furthermore, the comprehensive differential gene list and functional groups provided by this study constitute an interesting starting point to explore new targets and extended functional networks dealing with small bowel inflammation.
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Affiliation(s)
- Leela Rani Avula
- Department of Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Groenenborgerlaan 171, Antwerp B-2020, Belgium
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Hübner S, Efthymiadis A. Recent progress in histochemistry and cell biology. Histochem Cell Biol 2012; 137:403-57. [PMID: 22366957 DOI: 10.1007/s00418-012-0933-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2012] [Indexed: 01/06/2023]
Abstract
Studies published in Histochemistry and Cell Biology in the year 2011 represent once more a manifest of established and newly sophisticated techniques being exploited to put tissue- and cell type-specific molecules into a functional context. The review is therefore the Histochemistry and Cell Biology's yearly intention to provide interested readers appropriate summaries of investigations touching the areas of tissue biology, developmental biology, the biology of the immune system, stem cell research, the biology of subcellular compartments, in order to put the message of such studies into natural scientific-/human- and also pathological-relevant correlations.
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Affiliation(s)
- Stefan Hübner
- Institute of Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany.
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