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MAS-related G protein-coupled receptors X (MRGPRX): Orphan GPCRs with potential as targets for future drugs. Pharmacol Ther 2022; 238:108259. [DOI: 10.1016/j.pharmthera.2022.108259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/30/2022] [Accepted: 08/01/2022] [Indexed: 11/20/2022]
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Green DP. The role of Mrgprs in pain. Neurosci Lett 2021; 744:135544. [PMID: 33421487 DOI: 10.1016/j.neulet.2020.135544] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/16/2020] [Accepted: 11/26/2020] [Indexed: 11/17/2022]
Abstract
Owing to their functional diversity, the Mas-related G-protein-coupled receptor (Mrgpr) family has a role in both itch and pain modulation. While primarily linked to pruritis, Mrgprs were originally characterized in small-diameter nociceptive neurons of dorsal root ganglia (DRG) and trigeminal ganglia. This review will focus on the role Mrgpr's have in pain physiology, discussing recent discoveries as well as how Mrgpr's may provide a new target for the treatment of pathological pain.
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Affiliation(s)
- Dustin P Green
- Department of Neuroscience, Cell Biology, & Anatomy, University of Texas Medical Branch, Galveston, TX, USA
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Ali H. Emerging Roles for MAS-Related G Protein-Coupled Receptor-X2 in Host Defense Peptide, Opioid, and Neuropeptide-Mediated Inflammatory Reactions. Adv Immunol 2017; 136:123-162. [PMID: 28950944 DOI: 10.1016/bs.ai.2017.06.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mast cells (MCs) are tissue-resident immune cells that contribute to host defense but are best known for their roles in allergic and inflammatory diseases. In humans, MCs are divided into two subtypes based on the protease content of their secretory granules. Thus, human lung MCs contain only tryptase and are known as MCT, whereas skin MCs contain both tryptase and chymase and are known as MCTC. Patients with severe asthma display elevated MCs in the lung, which undergo phenotypic change from MCT to MCTC. Although the human genome contains four Mas related G protein coupled receptor X (MRGPRX) genes, an important feature of MCTC is that they selectively express MRGPRX2. It is activated by antimicrobial host defense peptides such as human β-defensins and the cathelicidin LL-37 and likely contributes to host defense. MRGPRX2 is also a receptor for the neuropeptide substance P, major basic protein, eosinophil peroxidase, opioids, and many FDA-approved cationic drugs. Increased expression of MRGPRX2 or enhanced downstream signaling likely contributes to chronic inflammatory diseases such as rosacea, atopic dermatitis, chronic urticaria, and severe asthma. In this chapter, I will discuss the expression profile and function of MRGPRX1-4 and review the emerging roles of MRGPRX2 on host defense, chronic inflammatory diseases, and drug-induced pseudoallergic reactions. I will also examine the novel aspects of MRGPRX2 signaling in MCs as it related to degranulation and review the mechanisms of its regulation.
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Affiliation(s)
- Hydar Ali
- University of Pennsylvania School of Dental Medicine, Philadelphia, PA, United States.
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Tiwari V, Tiwari V, He S, Zhang T, Raja SN, Dong X, Guan Y. Mas-Related G Protein-Coupled Receptors Offer Potential New Targets for Pain Therapy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 904:87-103. [PMID: 26900065 DOI: 10.1007/978-94-017-7537-3_7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The founding member of the Mas-related G-protein-coupled receptor (Mrgpr) family was discovered in 1986. Since then, many more members of this receptor family have been identified in multiple species, and their physiologic functions have been investigated widely. Because they are expressed exclusively in small-diameter primary sensory neurons, the roles of Mrgpr proteins in pain and itch have been best studied. This review will focus specifically on the current knowledge of their roles in pathological pain and the potential development of new pharmacotherapies targeted at some Mrgprs for the treatment of chronic pain. We will also discuss the limitations and future scope of this receptor family in pain treatment.
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Affiliation(s)
- Vineeta Tiwari
- Division of Pain Medicine, Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Vinod Tiwari
- Division of Pain Medicine, Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Shaoqiu He
- Division of Pain Medicine, Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Tong Zhang
- Division of Pain Medicine, Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Srinivasa N Raja
- Division of Pain Medicine, Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Xinzhong Dong
- Division of Pain Medicine, Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Yun Guan
- Division of Pain Medicine, Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA.
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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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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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Liu SV, Lenkiewicz E, Evers L, Holley T, Kiefer J, Ruiz C, Glatz K, Bubendorf L, Demeure MJ, Eng C, Ramanathan RK, Von Hoff DD, Barrett MT. Genomic analysis and selected molecular pathways in rare cancers. Phys Biol 2012. [DOI: 10.1088/1478-3975/9/6/065004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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