1
|
Yang H, Chen Y, Wang L, Gan B, Yu L, Ren R, Kwok HF, Wu Y, Cao Z. The fungal secretory peptide micasin induces itch by activating MRGPRX1/C11/A1 on peripheral neurons. J Invest Dermatol 2024:S0022-202X(24)01871-2. [PMID: 38945438 DOI: 10.1016/j.jid.2024.05.031] [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: 12/05/2023] [Revised: 05/03/2024] [Accepted: 05/07/2024] [Indexed: 07/02/2024]
Abstract
Pruritus is the leading symptom of dermatophytosis. Microsporium canis is one of the predominant dermatophytes causing dermatophytosis. However, the pruritogenic agents and the related molecular mechanisms of the dermatophyte M. canis remain poorly understood. Here, the secretion of the dermatophyte M. canis was found to dose-dependently evoke itch in mice. The fungal peptide micasin secreted from M. canis was then identified to elicit mouse significant scratching and itching responses. The peptide micasin was further revealed to directly activate mouse dorsal root ganglia (DRG) neurons to mediate the non-histaminergic itch. Knockout and antagonistic experiments demonstrated that MRGPRX1/C11/A1 rather than MRGPRX2/b2 activated by micasin contributed to pruritus. The chimera and mutation of MRGPRX1 showed that three domains (ECL3, TMH3 and TMH6) and four hydrophobic residues (Y99, F237, L240 and W241) of MRGPRX1 played the key role in micasin-triggered MRGPRX1 activation. Our study sheds light on the dermatophytosis-associated pruritus and may provide potential therapeutic targets and strategies against pruritus caused by dermatophytes.
Collapse
Affiliation(s)
- Haifeng Yang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei University of Technology, Wuhan, China; State Key Laboratory of Virology, College of Life Sciences, Shenzhen Research Institute, Wuhan University, Wuhan, China
| | - Yian Chen
- State Key Laboratory of Virology, College of Life Sciences, Shenzhen Research Institute, Wuhan University, Wuhan, China
| | - Luyao Wang
- State Key Laboratory of Virology, College of Life Sciences, Shenzhen Research Institute, Wuhan University, Wuhan, China
| | - Bing Gan
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China
| | - Leiye Yu
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China
| | - Ruobing Ren
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China
| | - Hang Fai Kwok
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Macau, Avenida de Universidade, Taipa, Macau SAR
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Shenzhen Research Institute, Wuhan University, Wuhan, China
| | - Zhijian Cao
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei University of Technology, Wuhan, China.
| |
Collapse
|
2
|
Butler DC, Berger T, Elmariah S, Kim B, Chisolm S, Kwatra SG, Mollanazar N, Yosipovitch G. Chronic Pruritus: A Review. JAMA 2024; 331:2114-2124. [PMID: 38809527 DOI: 10.1001/jama.2024.4899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Importance Chronic pruritus, defined as itch experienced for 6 weeks or longer, affects approximately 22% of people in their lifetime. Approximately 1% of physician visits are for the chief concern of chronic pruritus. Chronic pruritus is associated with adverse outcomes, including impaired sleep and reduced quality of life. Observations Chronic pruritus can be categorized by etiology into inflammatory, neuropathic, or a combination of inflammatory and neuropathic pruritus. Chronic pruritus is due to inflammation in approximately 60% of patients and may be caused by eczema, psoriasis, or seborrheic dermatitis. Chronic pruritus is due to a neuropathic or mixed etiology in approximately 25% of patients. Neuropathic causes of chronic pruritus include postherpetic neuralgia and notalgia paresthetica and are typically due to localized or generalized nerve dysregulation. Approximately 15% of people with chronic pruritus have other causes including systemic diseases with secondary itch, such as uremic pruritus and cholestatic pruritus, medication-induced pruritus such as pruritus due to immunotherapy, and infectious etiologies such as tinea corporis and scabies. When few primary changes are present, a thorough history, review of symptoms, and laboratory evaluation should be performed, particularly for people with chronic pruritus lasting less than 1 year. Clinicians should consider the following tests: complete blood cell count, complete metabolic panel, and thyroid function testing to evaluate for hematologic malignancy, liver disease, kidney disease, or thyroid disease. First-line treatment for inflammatory chronic pruritus includes topical anti-inflammatory therapies such as hydrocortisone (2.5%), triamcinolone (0.1%), or tacrolimus ointment. Approximately 10% of patients do not respond to topical therapies. In these patients, referral to dermatology and systemic oral or injectable treatments such as dupilumab or methotrexate may be considered. When no underlying systemic disease associated with pruritus is identified, patients are likely to have neuropathic chronic pruritus or mixed etiology such as chronic pruritus of unknown origin. In these patients, neuropathic topical treatments such as menthol, pramoxine, or lidocaine can be used either alone or in combination with immunomodulatory agents such as topical steroids. Other effective therapies for neuropathic pruritus include gabapentin, antidepressants such as sertraline or doxepin, or opioid receptor agonist/antagonists such as naltrexone or butorphanol. Conclusions and Relevance Chronic pruritus can adversely affect quality of life and can be categorized into inflammatory, neuropathic, or a combined etiology. First-line therapies are topical steroids for inflammatory causes, such as hydrocortisone (2.5%) or triamcinolone (0.1%); topical neuropathic agents for neuropathic causes, such as menthol or pramoxine; and combinations of these therapies for mixed etiologies of chronic pruritus.
Collapse
Affiliation(s)
| | - Timothy Berger
- Department of Dermatology, University of California, San Francisco
| | - Sarina Elmariah
- Department of Dermatology, University of California, San Francisco
| | - Brian Kim
- Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Sarah Chisolm
- Department of Dermatology, Emory University, Grady Memorial Hospital, Atlanta, Georgia
- Regional Telehealth Service, Veterans Affairs Veterans Integrated Service Network 7 Southeast Network, Duluth, Georgia
| | - Shawn G Kwatra
- Department of Dermatology, Johns Hopkins University School of Medicine and Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Nicholas Mollanazar
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Gil Yosipovitch
- Miami Itch Center, Phillip Frost Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, Florida
| |
Collapse
|
3
|
Chien DCC, Limjunyawong N, Cao C, Meixiong J, Peng Q, Ho CY, Fay JF, Roth BL, Dong X. MRGPRX4 mediates phospho-drug-associated pruritus in a humanized mouse model. Sci Transl Med 2024; 16:eadk8198. [PMID: 38718132 DOI: 10.1126/scitranslmed.adk8198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 04/12/2024] [Indexed: 05/30/2024]
Abstract
The phosphate modification of drugs is a common chemical strategy to increase solubility and allow for parenteral administration. Unfortunately, phosphate modifications often elicit treatment- or dose-limiting pruritus through an unknown mechanism. Using unbiased high-throughput drug screens, we identified the Mas-related G protein-coupled receptor X4 (MRGPRX4), a primate-specific, sensory neuron receptor previously implicated in itch, as a potential target for phosphate-modified compounds. Using both Gq-mediated calcium mobilization and G protein-independent GPCR assays, we found that phosphate-modified compounds potently activate MRGPRX4. Furthermore, a humanized mouse model expressing MRGPRX4 in sensory neurons exhibited robust phosphomonoester prodrug-evoked itch. To characterize and confirm this interaction, we further determined the structure of MRGPRX4 in complex with a phosphate-modified drug through single-particle cryo-electron microscopy (cryo-EM) and identified critical amino acid residues responsible for the binding of the phosphate group. Together, these findings explain how phosphorylated drugs can elicit treatment-limiting itch and identify MRGPRX4 as a potential therapeutic target to suppress itch and to guide future drug design.
Collapse
Affiliation(s)
- Daphne Chun-Che Chien
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nathachit Limjunyawong
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Can Cao
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - James Meixiong
- Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Qi Peng
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Cheng-Ying Ho
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jonathan F Fay
- Department of Biochemistry and Molecular Biology, University of Maryland Baltimore, Baltimore, MD 21201, USA
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Xinzhong Dong
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| |
Collapse
|
4
|
Qi L, Iskols M, Shi D, Reddy P, Walker C, Lezgiyeva K, Voisin T, Pawlak M, Kuchroo VK, Chiu IM, Ginty DD, Sharma N. A mouse DRG genetic toolkit reveals morphological and physiological diversity of somatosensory neuron subtypes. Cell 2024; 187:1508-1526.e16. [PMID: 38442711 PMCID: PMC10947841 DOI: 10.1016/j.cell.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 11/12/2023] [Accepted: 02/05/2024] [Indexed: 03/07/2024]
Abstract
Dorsal root ganglia (DRG) somatosensory neurons detect mechanical, thermal, and chemical stimuli acting on the body. Achieving a holistic view of how different DRG neuron subtypes relay neural signals from the periphery to the CNS has been challenging with existing tools. Here, we develop and curate a mouse genetic toolkit that allows for interrogating the properties and functions of distinct cutaneous targeting DRG neuron subtypes. These tools have enabled a broad morphological analysis, which revealed distinct cutaneous axon arborization areas and branching patterns of the transcriptionally distinct DRG neuron subtypes. Moreover, in vivo physiological analysis revealed that each subtype has a distinct threshold and range of responses to mechanical and/or thermal stimuli. These findings support a model in which morphologically and physiologically distinct cutaneous DRG sensory neuron subtypes tile mechanical and thermal stimulus space to collectively encode a wide range of natural stimuli.
Collapse
Affiliation(s)
- Lijun Qi
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Michael Iskols
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - David Shi
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Pranav Reddy
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Christopher Walker
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Karina Lezgiyeva
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Tiphaine Voisin
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - Mathias Pawlak
- Gene Lay Institute of Immunology and Inflammation, Brigham and Women's Hospital, Mass General Hospital, and Harvard Medical School, Boston, MA 02115, USA
| | - Vijay K Kuchroo
- Gene Lay Institute of Immunology and Inflammation, Brigham and Women's Hospital, Mass General Hospital, and Harvard Medical School, Boston, MA 02115, USA
| | - Isaac M Chiu
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
| | - Nikhil Sharma
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA.
| |
Collapse
|
5
|
Majumdar S, Chiu YT, Pickett JE, Roth BL. Illuminating the understudied GPCR-ome. Drug Discov Today 2024; 29:103848. [PMID: 38052317 DOI: 10.1016/j.drudis.2023.103848] [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: 10/03/2023] [Revised: 11/17/2023] [Accepted: 11/28/2023] [Indexed: 12/07/2023]
Abstract
G-protein-coupled receptors (GPCRs) are the target of >30% of approved drugs. Despite their popularity, many of the >800 human GPCRs remain understudied. The Illuminating the Druggable Genome (IDG) project has generated many tools leading to important insights into the function and druggability of these so-called 'dark' receptors. These tools include assays, such as PRESTO-TANGO and TRUPATH, billions of small molecules made available via the ZINC virtual library, solved orphan GPCR structures, GPCR knock-in mice, and more. Together, these tools are illuminating the remaining 'dark' GPCRs.
Collapse
Affiliation(s)
- Sreeparna Majumdar
- Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Yi-Ting Chiu
- Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Julie E Pickett
- Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Bryan L Roth
- Department of Pharmacology, UNC Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA.
| |
Collapse
|
6
|
Gour N, Yong HM, Magesh A, Atakkatan A, Andrade F, Lajoie S, Dong X. A GPCR-neuropeptide axis dampens hyperactive neutrophils by promoting an alternative-like polarization during bacterial infection. Immunity 2024; 57:333-348.e6. [PMID: 38295799 PMCID: PMC10940224 DOI: 10.1016/j.immuni.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 10/10/2023] [Accepted: 01/08/2024] [Indexed: 02/16/2024]
Abstract
The notion that neutrophils exist as a homogeneous population is being replaced with the knowledge that neutrophils adopt different functional states. Neutrophils can have a pro-inflammatory phenotype or an anti-inflammatory state, but how these states are regulated remains unclear. Here, we demonstrated that the neutrophil-expressed G-protein-coupled receptor (GPCR) Mrgpra1 is a negative regulator of neutrophil bactericidal functions. Mrgpra1-mediated signaling was driven by its ligand, neuropeptide FF (NPFF), which dictated the balance between pro- and anti-inflammatory programming. Specifically, the Mrgpra1-NPFF axis counter-regulated interferon (IFN) γ-mediated neutrophil polarization during acute lung infection by favoring an alternative-like polarization, suggesting that it may act to balance overzealous neutrophilic responses. Distinct, cross-regulated populations of neutrophils were the primary source of NPFF and IFNγ during infection. As a subset of neutrophils at steady state expressed NPFF, these findings could have broad implications in various infectious and inflammatory diseases. Therefore, a neutrophil-intrinsic pathway determines their cellular fate, function, and magnitude of infection.
Collapse
Affiliation(s)
- Naina Gour
- Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Hwan Mee Yong
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Aishwarya Magesh
- Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD, USA; Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Aishwarya Atakkatan
- Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Felipe Andrade
- Division of Rheumatology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Stephane Lajoie
- Department of Otolaryngology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Xinzhong Dong
- Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| |
Collapse
|
7
|
Gour N, Dong X. The MRGPR family of receptors in immunity. Immunity 2024; 57:28-39. [PMID: 38198852 PMCID: PMC10825802 DOI: 10.1016/j.immuni.2023.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/03/2023] [Accepted: 12/13/2023] [Indexed: 01/12/2024]
Abstract
The discovery of Mas-related G protein-coupled receptors (Mrgprs) has opened a compelling chapter in our understanding of immunity and sensory biology. This family of receptors, with their unique expression and diverse ligands, has emerged as key players in inflammatory states and hold the potential to alleviate human diseases. This review will focus on the members of this receptor family expressed on immune cells and how they govern immune and neuro-immune pathways underlying various physiological and pathological states. Immune cell-specific Mrgprs have been shown to control a variety of manifestations, including adverse drug reactions, inflammatory conditions, bacterial immunity, and the sensing of environmental exposures like allergens and irritants.
Collapse
Affiliation(s)
- Naina Gour
- Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
| | - Xinzhong Dong
- Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| |
Collapse
|
8
|
Marx D, Alnouri MW, Clemens S, Gedschold R, Riedel Y, Al Hamwi G, Pillaiyar T, Hockemeyer J, Namasivayam V, Müller CE. Discovery of Potent Agonists for the Predominant Variant of the Orphan MAS-Related G Protein-Coupled Receptor X4 (MRGPRX4). J Med Chem 2023; 66:15674-15698. [PMID: 37967029 DOI: 10.1021/acs.jmedchem.3c01013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
The MAS-related Gq protein-coupled receptor X4 (MRGPRX4) is poorly investigated. MRGPRX4 has been proposed to be involved in pain transmission, itch, inflammation, wound healing, and cancer. However, so far only a few moderately potent, nonselective MRGPRX4 agonists have been described, most of which appear to preferably activate the minor receptor variant MRGPRX4-83L but not the main variant 83S. In the present study, we discovered a xanthine derivative bearing a phosphate substituent that activates the main variant of MRGPRX4. Optimization resulted in analogs with high potency and metabolic stability. The best compounds of the present series include 8-(m-methoxyphenethyl)-1-propargylxanthine substituted with a butyl linker in the 3-position containing a terminal phosphonate (30d, PSB-22034, EC50 Ca2+ assay/β-arrestin assay, 11.2 nM/32.0 nM) and its N7-methyl derivative 31d (PSB-22040, EC50, 19.2/30.0 nM) showing high selectivity versus all other MRGPRX subtypes. They present promising tool compounds for exploring the potential of MRGPRX4 as a future drug target.
Collapse
Affiliation(s)
- Daniel Marx
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| | - Mohamed Wessam Alnouri
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| | - Sophie Clemens
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| | - Robin Gedschold
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| | - Yvonne Riedel
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| | - Ghazl Al Hamwi
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| | - Thanigaimalai Pillaiyar
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| | - Jörg Hockemeyer
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| | - Vigneshwaran Namasivayam
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| | - Christa E Müller
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- PharmaCenter Bonn, University of Bonn, Brühler Straße 7, D-53121 Bonn, Germany
| |
Collapse
|
9
|
Tsagareli MG, Follansbee T, Iodi Carstens M, Carstens E. Targeting Transient Receptor Potential (TRP) Channels, Mas-Related G-Protein-Coupled Receptors (Mrgprs), and Protease-Activated Receptors (PARs) to Relieve Itch. Pharmaceuticals (Basel) 2023; 16:1707. [PMID: 38139833 PMCID: PMC10748146 DOI: 10.3390/ph16121707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 11/24/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Itch (pruritus) is a sensation in the skin that provokes the desire to scratch. The sensation of itch is mediated through a subclass of primary afferent sensory neurons, termed pruriceptors, which express molecular receptors that are activated by itch-evoking ligands. Also expressed in pruriceptors are several types of Transient Receptor Potential (TRP) channels. TRP channels are a diverse class of cation channels that are responsive to various somatosensory stimuli like touch, pain, itch, and temperature. In pruriceptors, TRP channels can be activated through intracellular signaling cascades initiated by pruritogen receptors and underly neuronal activation. In this review, we discuss the role of TRP channels TRPA1, TRPV1, TRPV2, TRPV3, TRPV4, TRPM8, and TRPC3/4 in acute and chronic pruritus. Since these channels often mediate itch in association with pruritogen receptors, we also discuss Mas-related G-protein-coupled receptors (Mrgprs) and protease-activated receptors (PARs). Additionally, we cover the exciting therapeutic targets amongst the TRP family, as well as Mrgprs and PARs for the treatment of pruritus.
Collapse
Affiliation(s)
- Merab G. Tsagareli
- Laboratory of Pain and Analgesia, Ivane Beritashvili Center for Experimental Biomedicine, 0160 Tbilisi, Georgia;
| | - Taylor Follansbee
- Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA;
| | - Mirela Iodi Carstens
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, CA 95616, USA;
| | - Earl Carstens
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, CA 95616, USA;
| |
Collapse
|
10
|
Adorini L, Trauner M. FXR agonists in NASH treatment. J Hepatol 2023; 79:1317-1331. [PMID: 37562746 DOI: 10.1016/j.jhep.2023.07.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/19/2023] [Accepted: 07/16/2023] [Indexed: 08/12/2023]
Abstract
The farnesoid X receptor (FXR), a bile acid (BA)-activated nuclear receptor highly expressed in the liver and intestine, regulates the expression of genes involved in cholesterol and bile acid homeostasis, hepatic gluconeogenesis, lipogenesis, inflammation and fibrosis, in addition to controlling intestinal barrier integrity, preventing bacterial translocation and maintaining gut microbiota eubiosis. Non-alcoholic steatohepatitis (NASH), an advanced stage of non-alcoholic fatty liver disease, is characterized by hepatic steatosis, hepatocyte damage (ballooning) and inflammation, leading to fibrosis, cirrhosis and hepatocellular carcinoma. NASH represents a major unmet medical need, but no pharmacological treatments have yet been approved. The pleiotropic mechanisms involved in NASH development offer a range of therapeutic opportunities and among them FXR activation has emerged as an established pharmacological target. Various FXR agonists with different physicochemical properties, which can be broadly classified as BA derivatives, non-BA-derived steroidal FXR agonists, non-steroidal FXR agonists, and partial FXR agonists, are in advanced clinical development. In this review we will summarize key preclinical and clinical features of the most advanced FXR agonists and critically evaluate their potential in NASH treatment.
Collapse
Affiliation(s)
- Luciano Adorini
- Intercept Pharmaceuticals Inc., 305 Madison Ave., Morristown, NJ 07960, USA.
| | - Michael Trauner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
| |
Collapse
|
11
|
Rodrigo M, Dong X, Chien D, Karnsakul W. Cholestatic Pruritus in Children: Conventional Therapies and Beyond. BIOLOGY 2023; 12:biology12050756. [PMID: 37237568 DOI: 10.3390/biology12050756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/12/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023]
Abstract
Pruritus in the setting of cholestatic liver disease is difficult to treat and occurs in patients ranging in age from infancy to adulthood. Likely multifactorial in etiology, this symptom often involves multimodal therapy targeting several pathways and mechanisms proposed in the underlying etiology of cholestatic pruritus. Many patients in both the pediatric and adult populations continue to experience unrelenting pruritus despite maximal conventional therapy. Options are further limited in treating pediatric patients due to sparse data regarding medication safety and efficacy in younger patients. Conventional therapies for the treatment of cholestatic pruritus in children include ursodeoxycholic acid, cholestyramine, hydroxyzine, and rifampin. Certain therapies are more routinely used in the adult populations but with limited data available for use in child and adolescent patients, including opioid antagonists and selective serotonin reuptake inhibitors. Recently, ileal bile acid transport inhibitors have been shown to alleviate pruritus in many children with Alagille syndrome and progressive familial intrahepatic cholestasis and is an additional therapy available for consideration for these patients. Ultimately, surgical options such as biliary diversion or liver transplantation are considered in specific circumstances when medical therapies have been exhausted and pruritus remains debilitating. While further investigation regarding underlying etiologies and effective therapies are needed to better understand itch pathogenesis and treatment in pediatric cholestasis, current considerations beyond conventional management include the use of opioid antagonists, selective serotonin reuptake inhibitors, ileal bile acid transport inhibitors, and surgical intervention.
Collapse
Affiliation(s)
- Minna Rodrigo
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xinzhong Dong
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Daphne Chien
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Wikrom Karnsakul
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| |
Collapse
|
12
|
Du Z, Liu ZZ. Inhibition of aflatoxins on UDP-glucuronosyltransferases (UGTs). Toxicol In Vitro 2023; 90:105612. [PMID: 37164184 DOI: 10.1016/j.tiv.2023.105612] [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: 12/25/2022] [Revised: 04/25/2023] [Accepted: 05/06/2023] [Indexed: 05/12/2023]
Abstract
Aflatoxins have been recognized as the most harmful mycotoxins leading to various toxic effects. The present study aims to determine the inhibition behavior of aflatoxins on the activity of the important phase II metabolizing enzymes, UDP-glucuronosyltransferases (UGTs), based on in vitro incubation system of recombinant human UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU). 100 μM AFB1 and AFG1 exhibited extensive inhibition towards UGT isoforms especially UGT1A7 and UGT1A8, with the inhibition ratios to be 71.38%, 72.95% and 72.79% for AFB1 to UGT1A7, AFB1 to UGT1A8 and AFG1 to UGT1A8, respectively. Molecular docking results showed that hydrogen bonds and hydrophobic contacts of the particular structure consisting of double furan ring with double bond contributed to the interaction of aflatoxins and UGTs. Kinetics analysis, including inhibition types and kinetics parameters (Ki), and in vitro-in vivo extrapolation (IVIVE) indicated that there might be a medium possibility of inhibition on UGTs by aflatoxins in vivo. In conclusion, the present study indicated that aflatoxins could possibly disturb endogenous metabolism by inhibiting the activity of UGTs so as to exhibit toxic effects.
Collapse
Affiliation(s)
- Zuo Du
- School of Public Health, North Sichuan Medical College, Nanchong 637000, China.
| | - Zhen-Zhong Liu
- School of Public Health, North Sichuan Medical College, Nanchong 637000, China
| |
Collapse
|
13
|
Kotliar IB, Ceraudo E, Kemelmakher-Liben K, Oren DA, Lorenzen E, Dodig-Crnković T, Horioka-Duplix M, Huber T, Schwenk JM, Sakmar TP. Itch receptor MRGPRX4 interacts with the receptor activity-modifying proteins. J Biol Chem 2023; 299:104664. [PMID: 37003505 PMCID: PMC10165273 DOI: 10.1016/j.jbc.2023.104664] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/22/2023] [Accepted: 03/24/2023] [Indexed: 04/03/2023] Open
Abstract
Cholestatic itch is a severe and debilitating symptom in liver diseases with limited treatment options. The class A G protein-coupled receptor (GPCR) Mas-related GPCR subtype X4 (MRGPRX4) has been identified as a receptor for bile acids, which are potential cholestatic pruritogens. An increasing number of GPCRs have been shown to interact with receptor activity-modifying proteins (RAMPs), which can modulate different aspects of GPCR biology. Using a combination of multiplexed immunoassay and proximity ligation assay, we show that MRGPRX4 interacts with RAMPs. The interaction of MRGPRX4 with RAMP2, but not RAMP1 or 3, causes attenuation of basal and agonist-dependent signaling, which correlates with a decrease of MRGPRX4 cell surface expression as measured using a quantitative NanoBRET pulse-chase assay. Finally, we use AlphaFold Multimer to predict the structure of the MRGPRX4-RAMP2 complex. The discovery that RAMP2 regulates MRGPRX4 may have direct implications for future drug development for cholestatic itch.
Collapse
Affiliation(s)
- Ilana B Kotliar
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, New York, USA; Tri-Institutional PhD Program in Chemical Biology, New York, New York, USA
| | - Emilie Ceraudo
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, New York, USA
| | - Kevin Kemelmakher-Liben
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, New York, USA
| | - Deena A Oren
- Structural Biology Resource Center, The Rockefeller University, New York, New York, USA
| | - Emily Lorenzen
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, New York, USA
| | - Tea Dodig-Crnković
- Science for Life Laboratory, Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Solna, Sweden
| | - Mizuho Horioka-Duplix
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, New York, USA
| | - Thomas Huber
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, New York, USA
| | - Jochen M Schwenk
- Science for Life Laboratory, Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Solna, Sweden
| | - Thomas P Sakmar
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, New York, USA; Department of Neurobiology, Care Sciences and Society, Section for Neurogeriatrics, Karolinska Institutet, Solna, Sweden.
| |
Collapse
|
14
|
Sadler KE, Atkinson SN, Ehlers VL, Waltz TB, Hayward M, Rodríguez García DM, Salzman NH, Stucky CL, Brandow AM. Gut microbiota and metabolites drive chronic sickle cell disease pain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.25.538342. [PMID: 37163080 PMCID: PMC10168372 DOI: 10.1101/2023.04.25.538342] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Pain is a debilitating symptom and leading reason for hospitalization of individuals with sickle cell disease. Chronic sickle cell pain is poorly managed because the biological basis is not fully understood. Using transgenic sickle cell mice and fecal material transplant, we determined that the gut microbiome drives persistent sickle cell pain. In parallel patient and mouse analyses, we identified bilirubin as one metabolite that induces sickle cell pain by altering vagus nerve activity. Furthermore, we determined that decreased abundance of the gut bacteria Akkermansia mucinophila is a critical driver of chronic sickle cell pain. These experiments demonstrate that the sickle cell gut microbiome drives chronic widespread pain and identify bacterial species and metabolites that should be targeted for chronic sickle cell disease pain management.
Collapse
Affiliation(s)
- Katelyn E. Sadler
- Department of Neuroscience, The University of Texas at Dallas; Richardson, TX
- Center for Advanced Pain Studies, The University of Texas at Dallas; Richardson, TX
| | - Samantha N. Atkinson
- Center for Microbiome Research, Medical College of Wisconsin; Milwaukee, WI
- Department of Microbiology and Immunology, Medical College of Wisconsin; Milwaukee, WI
| | - Vanessa L. Ehlers
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin; Milwaukee, WI
| | - Tyler B. Waltz
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin; Milwaukee, WI
| | - Michael Hayward
- Center for Microbiome Research, Medical College of Wisconsin; Milwaukee, WI
- Department of Pediatrics, Division of Gastroenterology, Medical College of Wisconsin; Milwaukee, WI
| | | | - Nita H. Salzman
- Center for Microbiome Research, Medical College of Wisconsin; Milwaukee, WI
- Department of Microbiology and Immunology, Medical College of Wisconsin; Milwaukee, WI
- Department of Pediatrics, Division of Gastroenterology, Medical College of Wisconsin; Milwaukee, WI
| | - Cheryl L. Stucky
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin; Milwaukee, WI
| | - Amanda M. Brandow
- Department of Pediatrics, Section of Hematology/Oncology/Bone Marrow Transplantation, Medical College of Wisconsin; Milwaukee, WI
| |
Collapse
|
15
|
Qi L, Iskols M, Shi D, Reddy P, Walker C, Lezgiyeva K, Voisin T, Pawlak M, Kuchroo VK, Chiu I, Ginty DD, Sharma N. A DRG genetic toolkit reveals molecular, morphological, and functional diversity of somatosensory neuron subtypes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.22.537932. [PMID: 37131664 PMCID: PMC10153270 DOI: 10.1101/2023.04.22.537932] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Mechanical and thermal stimuli acting on the skin are detected by morphologically and physiologically distinct sensory neurons of the dorsal root ganglia (DRG). Achieving a holistic view of how this diverse neuronal population relays sensory information from the skin to the central nervous system (CNS) has been challenging with existing tools. Here, we used transcriptomic datasets of the mouse DRG to guide development and curation of a genetic toolkit to interrogate transcriptionally defined DRG neuron subtypes. Morphological analysis revealed unique cutaneous axon arborization areas and branching patterns of each subtype. Physiological analysis showed that subtypes exhibit distinct thresholds and ranges of responses to mechanical and/or thermal stimuli. The somatosensory neuron toolbox thus enables comprehensive phenotyping of most principal sensory neuron subtypes. Moreover, our findings support a population coding scheme in which the activation thresholds of morphologically and physiologically distinct cutaneous DRG neuron subtypes tile multiple dimensions of stimulus space.
Collapse
Affiliation(s)
- Lijun Qi
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
| | - Michael Iskols
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
| | - David Shi
- Department of Molecular Pharmacology and Therapeutics, Department of Systems Biology, Columbia University, New York, NY
| | - Pranav Reddy
- Department of Molecular Pharmacology and Therapeutics, Department of Systems Biology, Columbia University, New York, NY
| | - Christopher Walker
- Department of Molecular Pharmacology and Therapeutics, Department of Systems Biology, Columbia University, New York, NY
| | - Karina Lezgiyeva
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
| | - Tiphaine Voisin
- Department of Immunology, Harvard Medical School, Boston, MA 02115
| | - Mathias Pawlak
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Vijay K. Kuchroo
- Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Isaac Chiu
- Department of Immunology, Harvard Medical School, Boston, MA 02115
| | - David D. Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
| | - Nikhil Sharma
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115
- Department of Molecular Pharmacology and Therapeutics, Department of Systems Biology, Columbia University, New York, NY
| |
Collapse
|
16
|
Cao C, Roth BL. The structure, function, and pharmacology of MRGPRs. Trends Pharmacol Sci 2023; 44:237-251. [PMID: 36870785 PMCID: PMC10066734 DOI: 10.1016/j.tips.2023.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/01/2023] [Accepted: 02/09/2023] [Indexed: 03/06/2023]
Abstract
Mas-related G protein-coupled receptor (MRGPR) family members play important roles in the sensation of noxious stimuli and represent novel targets for the treatment of itch and pain. MRGPRs recognize a diversity of agonists and display complicated downstream signaling profiles, high sequence diversity across species, and many polymorphisms in humans. The recent structural advances on MRGPRs reveal unique structural features and diverse agonist recognition modes of this receptor family, which should facilitate the structure-based drug discovery at MRGPRs. In addition, the newly discovered ligands also provide valuable tools to explore the function and the therapeutic potential of MRGPRs. In this review, we discuss these progresses in our understanding of MRGPRs and highlight the challenges and potential opportunities for the future drug discovery at these receptors.
Collapse
Affiliation(s)
- Can Cao
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Division of Chemical Biology and Medicinal Chemistry, Eschelman School of Pharmacy and NIMH Psychoactive Drug Screening Program, University of North Carolina, Chapel Hill, NC 27599, USA.
| |
Collapse
|
17
|
Vitek L, Hinds TD, Stec DE, Tiribelli C. The physiology of bilirubin: health and disease equilibrium. Trends Mol Med 2023; 29:315-328. [PMID: 36828710 PMCID: PMC10023336 DOI: 10.1016/j.molmed.2023.01.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 02/24/2023]
Abstract
Bilirubin has several physiological functions, both beneficial and harmful. In addition to reactive oxygen species-scavenging activities, bilirubin has potent immunosuppressive effects associated with long-term pathophysiological sequelae. It has been recently recognized as a hormone with endocrine actions and interconnected effects on various cellular signaling pathways. Current studies show that bilirubin also decreases adiposity and prevents metabolic and cardiovascular diseases. All in all, the physiological importance of bilirubin is only now coming to light, and strategies for increasing plasma bilirubin levels to combat chronic diseases are starting to be considered. This review discusses the beneficial effects of increasing plasma bilirubin, incorporates emerging areas of bilirubin biology, and provides key concepts to advance the field.
Collapse
Affiliation(s)
- Libor Vitek
- Fourth Department of Internal Medicine and Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 120 00 Prague, Czech Republic
| | - Terry D Hinds
- Department of Pharmacology and Nutritional Sciences, Barnstable Brown Diabetes Center, Markey Cancer Center, University of Kentucky, Lexington, KY 40508, USA
| | - David E Stec
- Department of Physiology and Biophysics, Cardiorenal, and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | | |
Collapse
|
18
|
Liu HW, Gong LN, Lai K, Yu XF, Liu ZQ, Li MX, Yin XL, Liang M, Shi HS, Jiang LH, Yang W, Shi HB, Wang LY, Yin SK. Bilirubin gates the TRPM2 channel as a direct agonist to exacerbate ischemic brain damage. Neuron 2023; 111:1609-1625.e6. [PMID: 36921602 DOI: 10.1016/j.neuron.2023.02.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 10/18/2022] [Accepted: 02/13/2023] [Indexed: 03/16/2023]
Abstract
Stroke prognosis is negatively associated with an elevation of serum bilirubin, but how bilirubin worsens outcomes remains mysterious. We report that post-, but not pre-, stroke bilirubin levels among inpatients scale with infarct volume. In mouse models, bilirubin increases neuronal excitability and ischemic infarct, whereas ischemic insults induce the release of endogenous bilirubin, all of which are attenuated by knockout of the TRPM2 channel or its antagonist A23. Independent of canonical TRPM2 intracellular agonists, bilirubin and its metabolic derivatives gate the channel opening, whereas A23 antagonizes it by binding to the same cavity. Knocking in a loss of binding point mutation for bilirubin, TRPM2-D1066A, effectively antagonizes ischemic neurotoxicity in mice. These findings suggest a vicious cycle of stroke injury in which initial ischemic insults trigger the release of endogenous bilirubin from injured cells, which potentially acts as a volume neurotransmitter to activate TRPM2 channels, aggravating Ca2+-dependent brain injury.
Collapse
Affiliation(s)
- Han-Wei Liu
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Li-Na Gong
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Ke Lai
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Program in Neuroscience and Mental Health, SickKids Research Institute, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Xia-Fei Yu
- Department of Biophysics, Institute of Neuroscience, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Zhen-Qi Liu
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Program in Neuroscience and Mental Health, SickKids Research Institute, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Ming-Xian Li
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Xin-Lu Yin
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Department of Head & Neck Surgery, Renji Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Min Liang
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Department of Otorhinolaryngology Head & Neck Surgery, Xinhua Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Hao-Song Shi
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Lin-Hua Jiang
- Department of Physiology and Pathophysiology, School of Basic Sciences, Xinxiang Medical University, Xinxiang, Henan Province 453003, China; School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Wei Yang
- Department of Biophysics, Institute of Neuroscience, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Hai-Bo Shi
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China.
| | - Lu-Yang Wang
- Program in Neuroscience and Mental Health, SickKids Research Institute, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.
| | - Shan-Kai Yin
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital and Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China.
| |
Collapse
|
19
|
Vander Does A, Ju T, Mohsin N, Chopra D, Yosipovitch G. How to get rid of itching. Pharmacol Ther 2023; 243:108355. [PMID: 36739914 DOI: 10.1016/j.pharmthera.2023.108355] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/01/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023]
Abstract
Itch is an unpleasant sensation arising from a variety of dermatologic, neuropathic, systemic, and psychogenic etiologies. Various itch pathways are implicated according to the underlying etiology. A variety of pruritogens, or itch mediators, as well as receptors have been identified and provide potential therapeutic targets. Recent research has primarily focused on targeting inflammatory cytokines and Janus kinase signaling, protease-activated receptors, substance P and neurokinin, transient receptor potential-vanilloid ion channels, Mas-related G-protein-coupled receptors (MRGPRX2 and MRGPRX4), the endogenous opioid and cannabinoid balance, and phosphodiesterase 4. Periostin, a newly identified pruritogen, should be further explored with clinical trials. Drugs targeting neural sensitization including the gabergic system and P2X3 are other potential drugs for chronic itch. There is a need for more targeted therapies to improve clinical outcomes and reduce side effects.
Collapse
Affiliation(s)
- Ashley Vander Does
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA
| | - Teresa Ju
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA
| | - Noreen Mohsin
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA
| | - Divya Chopra
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA
| | - Gil Yosipovitch
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA.
| |
Collapse
|
20
|
Suppressing Hepatic UGT1A1 Increases Plasma Bilirubin, Lowers Plasma Urobilin, Reorganizes Kinase Signaling Pathways and Lipid Species and Improves Fatty Liver Disease. Biomolecules 2023; 13:biom13020252. [PMID: 36830621 PMCID: PMC9953728 DOI: 10.3390/biom13020252] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 01/31/2023] Open
Abstract
Several population studies have observed lower serum bilirubin levels in patients with non-alcoholic fatty liver disease (NAFLD). Yet, treatments to target this metabolic phenotype have not been explored. Therefore, we designed an N-Acetylgalactosamine (GalNAc) labeled RNAi to target the enzyme that clears bilirubin from the blood, the UGT1A1 glucuronyl enzyme (GNUR). In this study, male C57BL/6J mice were fed a high-fat diet (HFD, 60%) for 30 weeks to induce NAFLD and were treated subcutaneously with GNUR or sham (CTRL) once weekly for six weeks while continuing the HFD. The results show that GNUR treatments significantly raised plasma bilirubin levels and reduced plasma levels of the bilirubin catabolized product, urobilin. We show that GNUR decreased liver fat content and ceramide production via lipidomics and lowered fasting blood glucose and insulin levels. We performed extensive kinase activity analyses using our PamGene PamStation kinome technology and found a reorganization of the kinase pathways and a significant decrease in inflammatory mediators with GNUR versus CTRL treatments. These results demonstrate that GNUR increases plasma bilirubin and reduces plasma urobilin, reducing NAFLD and inflammation and improving overall liver health. These data indicate that UGT1A1 antagonism might serve as a treatment for NAFLD and may improve obesity-associated comorbidities.
Collapse
|
21
|
Pathogenesis and Treatment of Pruritus Associated with Chronic Kidney Disease and Cholestasis. Int J Mol Sci 2023; 24:ijms24021559. [PMID: 36675074 PMCID: PMC9864517 DOI: 10.3390/ijms24021559] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/07/2023] [Accepted: 01/11/2023] [Indexed: 01/14/2023] Open
Abstract
Itching is an unpleasant sensation that provokes the desire to scratch. In general, itching is caused by dermatologic diseases, but it can also be caused by systemic diseases. Since itching hampers patients' quality of life, it is important to understand the appropriate treatment and pathophysiology of pruritus caused by systemic diseases to improve the quality of life. Mechanisms are being studied through animal or human studies, and various treatments are being tested through clinical trials. We report current trends of two major systemic diseases: chronic kidney disease and cholestatic liver disease. This review summarizes the causes and pathophysiology of systemic diseases with pruritus and appropriate treatments. This article will contribute to patients' quality of life. Further research will help understand the mechanisms and develop new strategies in the future.
Collapse
|
22
|
Wu C, Jin Y, Cui Y, Zhu Y, Yin S, Li C. Effects of bilirubin on the development and electrical activity of neural circuits. Front Cell Neurosci 2023; 17:1136250. [PMID: 37025700 PMCID: PMC10070809 DOI: 10.3389/fncel.2023.1136250] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 03/06/2023] [Indexed: 04/08/2023] Open
Abstract
In the past several decades, bilirubin has attracted great attention for central nervous system (CNS) toxicity in some pathological conditions with severely elevated bilirubin levels. CNS function relies on the structural and functional integrity of neural circuits, which are large and complex electrochemical networks. Neural circuits develop from the proliferation and differentiation of neural stem cells, followed by dendritic and axonal arborization, myelination, and synapse formation. The circuits are immature, but robustly developing, during the neonatal period. It is at the same time that physiological or pathological jaundice occurs. The present review comprehensively discusses the effects of bilirubin on the development and electrical activity of neural circuits to provide a systematic understanding of the underlying mechanisms of bilirubin-induced acute neurotoxicity and chronic neurodevelopmental disorders.
Collapse
|
23
|
Mechanisms of pruritus in cholestasis: understanding and treating the itch. Nat Rev Gastroenterol Hepatol 2023; 20:26-36. [PMID: 36307649 DOI: 10.1038/s41575-022-00687-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/07/2022] [Indexed: 02/01/2023]
Abstract
Pruritus in cholestatic liver diseases can be a major burden and dramatically impair the quality of life of those affected. Here, we provide an update on the latest insights into the molecular pathogenesis of and novel therapeutic approaches for cholestasis-associated itch. Endogenous and exogenous small-molecule pruritogen candidates bind to their receptors on unmyelinated itch C-fibres in the skin. Candidate pruritogens in cholestasis include certain lysophospholipids and sulfated progesterone metabolites, among others, whereas total bile acid or bilirubin conjugates seem unlikely to have a dominant role in the pathogenesis of cholestasis-associated pruritus. Transmission of itch signals via primary, secondary and tertiary itch neurons to the postcentral gyrus and activation of scratch responses offer various targets for therapeutic intervention. At present, evidence-based treatment options for pruritus in fibrosing cholangiopathies, such as primary biliary cholangitis and primary sclerosing cholangitis, are the peroxisome proliferator-associated receptor (PPAR) agonist bezafibrate and the pregnane X receptor (PXR) agonist rifampicin. In pruritus of intrahepatic cholestasis of pregnancy, ursodeoxycholic acid is recommended and might be supported in the third trimester by rifampicin if needed. Alternatively, non-absorbable anion exchange resins, such as cholestyramine, can be administered, albeit with poor trial evidence. Liver transplantation for intolerable refractory pruritus has become an extremely rare therapeutic strategy.
Collapse
|
24
|
Zhu D, Wang M, Zhang Z, Liu M, Liu Y, Wu W, Lu D, Wu X, Wu W, Wang X. A metabolomic-based biomarker discovery study for predicting phototherapy duration for neonatal hyperbilirubinemia. Transl Pediatr 2022; 11:2016-2029. [PMID: 36643669 PMCID: PMC9834951 DOI: 10.21037/tp-22-637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Phototherapy is a recommended method for the treatment of neonatal hyperbilirubinemia. However, biomarkers for predicting the more effective duration of phototherapy prior to treatment are lacking. Therefore, we aimed to determine novel predictors for the timing of phototherapy from the perspective of metabolomics. METHODS A total of 12 newborns with neonatal hyperbilirubinemia were recruited on the day of admission. The infants were divided into a short-duration (<30 hours) phototherapy group and a long-duration (≥30 hours) phototherapy group based on the length of phototherapy treatment. Metabolites in serum samples were then explored using an untargeted metabolomics strategy. RESULTS In total, 59 of 1,073 significantly different metabolites were identified between the short-duration and long-duration phototherapy groups, including 18 upregulated and 41 downregulated metabolites. The results of metabolomic analysis showed that the differentially expressed metabolites were enriched in glycerophospholipid metabolism, which is closely associated with the excretion of bilirubin. Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the metabolites were also enriched in alpha-Linolenic acid metabolism and fatty acid elongation. Spearman correlation hierarchical clustering analysis demonstrated that 9 metabolites were negatively correlated with the duration of phototherapy. Metabolites, especially phosphatidylethanolamine (PE) (22:1(13Z)/15:0), phosphatidylcholine (PC) (18:1(9Z)/18:1(9Z)), phosphatidylserine (PS) (22:0/15:0), 5,6-dihydrouridine, and PE (MonoMe(11,3)/MonoMe(13,5)), had better predictability for the duration of phototherapy [area under curve (AUC): 1; 95% confidence interval (CI): 1-1] than total serum total bilirubin and direct bilirubin (AUC: 0.806; 95% CI: 0.55-1), as revealed by receiver operating characteristic analysis. CONCLUSIONS Our research found that the differential metabolites were associated with the duration of neonatal jaundice and that glycerophospholipid metabolism might have played a role in this biological process. Moreover, metabolites such as PE (22:1(13Z)/15:0), PC (18:1(9Z)/18:1(9Z)), PS (22:0/15:0), 5,6-dihydrouridine, and PE (MonoMe(11,3)/MonoMe(13,5)) could be used as predictors for phototherapy duration in neonatal hyperbilirubinemia and assist with decision-making.
Collapse
Affiliation(s)
- Danying Zhu
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Respiratory Medicine, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Mingjie Wang
- Department of Pediatrics, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zhongxiao Zhang
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Minghua Liu
- Department of Pediatrics, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yiwen Liu
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weiling Wu
- Department of Pediatrics, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Dian Lu
- Department of Pediatrics, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xiaoyun Wu
- Department of Pediatrics, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wei Wu
- Department of Pediatrics, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xingyun Wang
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| |
Collapse
|
25
|
Abstract
Chronic pruritus is a classic symptom in patients with primary biliary cholangitis. It affects up to two-thirds of patients in the course of the disease. Efficient therapy consists of topical treatment combined with systemic options such as anion exchangers, rifampicin, bezafibrate, μ-opioid receptor antagonists, selective-serotonin receptor uptake inhibitors, and gabapentinoids. Future therapeutic approaches may contain the selective blockade of the enterohepatic cycle by inhibiting the ileal bile acid transporter, the agonism at κ-opioid receptors, and antagonism of the mas-related G protein-coupled receptor X4. As nondrug treatment, ultraviolet B therapy, albumin dialysis, and biliary drainage are available at specialized centers.
Collapse
Affiliation(s)
- Miriam M Düll
- Department of Medicine 1, Gastroenterology, Hepatology, Pneumology, Endocrinology, University Hospital Erlangen and Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Ulmenweg 18, 91054 Erlangen, Germany
| | - Andreas E Kremer
- Department of Gastroenterology and Hepatology, Universitäts Spital Zürich, Rämistrasse 100, 8091 Zürich, Switzerland.
| |
Collapse
|
26
|
Abstract
Bile acids wear many hats, including those of an emulsifier to facilitate nutrient absorption, a cholesterol metabolite, and a signaling molecule in various tissues modulating itching to metabolism and cellular functions. Bile acids are synthesized in the liver but exhibit wide-ranging effects indicating their ability to mediate organ-organ crosstalk. So, how does a steroid metabolite orchestrate such diverse functions? Despite the inherent chemical similarity, the side chain decorations alter the chemistry and biology of the different bile acid species and their preferences to bind downstream receptors distinctly. Identification of new modifications in bile acids is burgeoning, and some of it is associated with the microbiota within the intestine. Here, we provide a brief overview of the history and the various receptors that mediate bile acid signaling in addition to its crosstalk with the gut microbiota.
Collapse
Affiliation(s)
| | | | - Sayeepriyadarshini Anakk
- Correspondence: Sayeepriyadarshini Anakk, PhD, Department of Molecular & Integrative Physiology, University of Illinois at Urbana-Champaign, 506 S Mathews Ave, 453 Medical Sciences Bldg, Urbana, IL 61801, USA.
| |
Collapse
|
27
|
Vasavda C, Xu R, Liew J, Kothari R, Dhindsa RS, Semenza ER, Paul BD, Green DP, Sabbagh MF, Shin JY, Yang W, Snowman AM, Albacarys LK, Moghekar A, Pardo-Villamizar CA, Luciano M, Huang J, Bettegowda C, Kwatra SG, Dong X, Lim M, Snyder SH. Identification of the NRF2 transcriptional network as a therapeutic target for trigeminal neuropathic pain. SCIENCE ADVANCES 2022; 8:eabo5633. [PMID: 35921423 PMCID: PMC9348805 DOI: 10.1126/sciadv.abo5633] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 06/16/2022] [Indexed: 05/28/2023]
Abstract
Trigeminal neuralgia, historically dubbed the "suicide disease," is an exceedingly painful neurologic condition characterized by sudden episodes of intense facial pain. Unfortunately, the only U.S. Food and Drug Administration (FDA)-approved medication for trigeminal neuralgia carries substantial side effects, with many patients requiring surgery. Here, we identify the NRF2 transcriptional network as a potential therapeutic target. We report that cerebrospinal fluid from patients with trigeminal neuralgia accumulates reactive oxygen species, several of which directly activate the pain-transducing channel TRPA1. Similar to our patient cohort, a mouse model of trigeminal neuropathic pain also exhibits notable oxidative stress. We discover that stimulating the NRF2 antioxidant transcriptional network is as analgesic as inhibiting TRPA1, in part by reversing the underlying oxidative stress. Using a transcriptome-guided drug discovery strategy, we identify two NRF2 network modulators as potential treatments. One of these candidates, exemestane, is already FDA-approved and may thus be a promising alternative treatment for trigeminal neuropathic pain.
Collapse
Affiliation(s)
- Chirag Vasavda
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Risheng Xu
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jason Liew
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ruchita Kothari
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ryan S. Dhindsa
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, USA
| | - Evan R. Semenza
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bindu D. Paul
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Dustin P. Green
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
| | - Mark F. Sabbagh
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Joseph Y. Shin
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Wuyang Yang
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Adele M. Snowman
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Lauren K. Albacarys
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Abhay Moghekar
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Mark Luciano
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Judy Huang
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Chetan Bettegowda
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shawn G. Kwatra
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michael Lim
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Solomon H. Snyder
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
28
|
Cholestatic Itch: Our Current Understanding of Pathophysiology and Treatments. Am J Clin Dermatol 2022; 23:647-659. [PMID: 35900649 DOI: 10.1007/s40257-022-00710-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2022] [Indexed: 11/01/2022]
Abstract
Hepatic pruritus is common in liver conditions, including cholestasis and nonalcoholic fatty liver disease. The pruritus can be severe enough to diminish sleep and decrease quality of life. The pathophysiology likely involves many molecules and receptors, including bile acids, bilirubin, lysophosphatidic acid (LPA), endogenous opioids, and serotonin. Recent advances suggest a significant role of Mas-related G protein-coupled receptor X4 (MRGPRX4) and autotaxin/LPA as key players in cholestatic pruritus. Further research is needed to develop increasingly targeted therapies with greater efficacy, especially given that many patients report itch refractory to various treatments. Cholestyramine was the only US FDA-approved drug for cholestatic pruritus until recent approval of ileal bile acid transporter (IBAT) inhibitors for use in the pediatric cholestatic conditions, progressive familial intrahepatic cholestasis and Alagille syndrome. Both medications decrease the bile acid pool. IBAT inhibitors are under investigation for broader use, and targeting LPA receptors and MRGPR4 are additional attractive options.
Collapse
|
29
|
Vasavda C, Semenza ER, Liew J, Kothari R, Dhindsa RS, Shanmukha S, Lin A, Tokhunts R, Ricco C, Snowman AM, Albacarys L, Pastore F, Ripoli C, Grassi C, Barone E, Kornberg MD, Dong X, Paul BD, Snyder SH. Biliverdin reductase bridges focal adhesion kinase to Src to modulate synaptic signaling. Sci Signal 2022; 15:eabh3066. [PMID: 35536885 PMCID: PMC9281001 DOI: 10.1126/scisignal.abh3066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Synapses connect discrete neurons into vast networks that send, receive, and encode diverse forms of information. Synaptic function and plasticity, the neuronal process of adapting to diverse and variable inputs, depend on the dynamic nature of synaptic molecular components, which is mediated in part by cell adhesion signaling pathways. Here, we found that the enzyme biliverdin reductase (BVR) physically links together key focal adhesion signaling molecules at the synapse. BVR-null (BVR-/-) mice exhibited substantial deficits in learning and memory on neurocognitive tests, and hippocampal slices in which BVR was postsynaptically depleted showed deficits in electrophysiological responses to stimuli. RNA sequencing, biochemistry, and pathway analyses suggested that these deficits were mediated through the loss of focal adhesion signaling at both the transcriptional and biochemical level in the hippocampus. Independently of its catalytic function, BVR acted as a bridge between the primary focal adhesion signaling kinases FAK and Pyk2 and the effector kinase Src. Without BVR, FAK and Pyk2 did not bind to and stimulate Src, which then did not phosphorylate the N-methyl-d-aspartate (NMDA) receptor, a critical posttranslational modification for synaptic plasticity. Src itself is a molecular hub on which many signaling pathways converge to stimulate NMDAR-mediated neurotransmission, thus positioning BVR at a prominent intersection of synaptic signaling.
Collapse
Affiliation(s)
- Chirag Vasavda
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Evan R. Semenza
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Jason Liew
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ruchita Kothari
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ryan S. Dhindsa
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA,Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX 77030, USA
| | - Shruthi Shanmukha
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Anthony Lin
- Department of Medicine, University of California, San Francisco, CA 94143, USA
| | - Robert Tokhunts
- Department of Anesthesiology, Dartmouth–Hitchcock Medical Center, Lebanon, NH 03766, USA
| | - Cristina Ricco
- Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08901, USA
| | - Adele M. Snowman
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Lauren Albacarys
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Francesco Pastore
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome 00168, Italy,Preclinical Neuroscience Lab, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome 00168, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome 00168, Italy,Preclinical Neuroscience Lab, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome 00168, Italy
| | - Eugenio Barone
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of Rome, Rome 00185, Italy
| | - Michael D. Kornberg
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Bindu D. Paul
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Correspondence to: ,
| | - Solomon H. Snyder
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA,Correspondence to: ,
| |
Collapse
|
30
|
Stec DE, Tiribelli C, Badmus OO, Hinds TD. Novel Function for Bilirubin as a Metabolic Signaling Molecule: Implications for Kidney Diseases. KIDNEY360 2022; 3:945-953. [PMID: 36128497 PMCID: PMC9438427 DOI: 10.34067/kid.0000062022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/24/2022] [Indexed: 01/30/2023]
Abstract
Bilirubin is the end product of the catabolism of heme via the heme oxygenase pathway. Heme oxygenase generates carbon monoxide (CO) and biliverdin from the breakdown of heme, and biliverdin is rapidly reduced to bilirubin by the enzyme biliverdin reductase (BVR). Bilirubin has long been thought of as a toxic product that is only relevant to health when blood levels are severely elevated, such as in clinical jaundice. The physiologic functions of bilirubin correlate with the growing body of evidence demonstrating the protective effects of serum bilirubin against cardiovascular and metabolic diseases. Although the correlative evidence suggests a protective effect of serum bilirubin against many diseases, the mechanism by which bilirubin offers protection against cardiovascular and metabolic diseases remains unanswered. We recently discovered a novel function for bilirubin as a signaling molecule capable of activating the peroxisome proliferator-activated receptor α (PPARα) transcription factor. This review summarizes the new finding of bilirubin as a signaling molecule and proposes several mechanisms by which this novel action of bilirubin may protect against cardiovascular and kidney diseases.
Collapse
Affiliation(s)
- David E. Stec
- Department of Physiology and Biophysics, Cardiorenal, and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | | | - Olufunto O. Badmus
- Department of Physiology and Biophysics, Cardiorenal, and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Terry D. Hinds
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky,Barnstable Brown Diabetes Center, University of Kentucky, Lexington, Kentucky,Markey Cancer Center, University of Kentucky, Lexington, Kentucky
| |
Collapse
|
31
|
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.
Collapse
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
| |
Collapse
|
32
|
Kothari R, Dong X. Scratching the surface of itch receptors. Trends Pharmacol Sci 2022; 43:168-170. [PMID: 35039148 DOI: 10.1016/j.tips.2021.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 01/07/2023]
Abstract
The discovery of Mas-related G protein-coupled receptors (MRGPRs) in itch sensation promised a search for novel therapeutics of itch that ultimately met with little success. Recent structural determination of these receptors by Roth and Sun marks a big step forward in the search for therapeutics of debilitating itch.
Collapse
Affiliation(s)
- Ruchita Kothari
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| |
Collapse
|
33
|
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.
Collapse
|
34
|
Vítek L, Tiribelli C. Bilirubin: The yellow hormone? J Hepatol 2021; 75:1485-1490. [PMID: 34153399 DOI: 10.1016/j.jhep.2021.06.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/19/2021] [Accepted: 06/10/2021] [Indexed: 12/22/2022]
Abstract
Bilirubin is a tetrapyrrolic compound originating from heme catabolism. Although originally considered only a potentially dangerous waste product, it has become increasingly evident that this molecule represents an important modulator of various biological functions in the human body. Bilirubin appears to have versatile functions, from cell signaling (behaving almost like a "real" hormonal substance), modulation of metabolism, to immune regulation, affecting biological activities with apparent clinical and even therapeutic consequences. These activities may be the reason for the lower incidence of diseases of civilisation (cardiovascular diseases, arterial hypertension, diabetes, obesity, metabolic syndrome, certain cancers, autoimmune, and neurodegenerative diseases) observed in individuals with a chronic mild unconjugated hyperbilirubinemia, a typical sign of Gilbert's syndrome. While higher serum concentrations of unconjugated bilirubin may serve as an important protective factor against these diseases, low levels of bilirubin are associated with the opposite effect.
Collapse
Affiliation(s)
- Libor Vítek
- Faculty General Hospital and 1(st) Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
| | | |
Collapse
|
35
|
Cao C, Kang HJ, Singh I, Chen H, Zhang C, Ye W, Hayes BW, Liu J, Gumpper RH, Bender BJ, Slocum ST, Krumm BE, Lansu K, McCorvy JD, Kroeze WK, English JG, DiBerto JF, Olsen RHJ, Huang XP, Zhang S, Liu Y, Kim K, Karpiak J, Jan LY, Abraham SN, Jin J, Shoichet BK, Fay JF, Roth BL. Structure, function and pharmacology of human itch GPCRs. Nature 2021; 600:170-175. [PMID: 34789874 PMCID: PMC9150435 DOI: 10.1038/s41586-021-04126-6] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 10/08/2021] [Indexed: 11/09/2022]
Abstract
The MRGPRX family of receptors (MRGPRX1-4) is a family of mas-related G-protein-coupled receptors that have evolved relatively recently1. Of these, MRGPRX2 and MRGPRX4 are key physiological and pathological mediators of itch and related mast cell-mediated hypersensitivity reactions2-5. MRGPRX2 couples to both Gi and Gq in mast cells6. Here we describe agonist-stabilized structures of MRGPRX2 coupled to Gi1 and Gq in ternary complexes with the endogenous peptide cortistatin-14 and with a synthetic agonist probe, respectively, and the development of potent antagonist probes for MRGPRX2. We also describe a specific MRGPRX4 agonist and the structure of this agonist in a complex with MRGPRX4 and Gq. Together, these findings should accelerate the structure-guided discovery of therapeutic agents for pain, itch and mast cell-mediated hypersensitivity.
Collapse
MESH Headings
- Cryoelectron Microscopy
- Drug Inverse Agonism
- GTP-Binding Protein alpha Subunits, Gi-Go/chemistry
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gi-Go/ultrastructure
- GTP-Binding Protein alpha Subunits, Gq-G11/chemistry
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/ultrastructure
- Humans
- Models, Molecular
- Nerve Tissue Proteins/antagonists & inhibitors
- Nerve Tissue Proteins/chemistry
- Nerve Tissue Proteins/metabolism
- Nerve Tissue Proteins/ultrastructure
- Pruritus/metabolism
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/ultrastructure
- Receptors, Neuropeptide/antagonists & inhibitors
- Receptors, Neuropeptide/chemistry
- Receptors, Neuropeptide/metabolism
- Receptors, Neuropeptide/ultrastructure
Collapse
Affiliation(s)
- Can Cao
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Hye Jin Kang
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Isha Singh
- Department of Pharmaceutical Sciences, University of California San Francisco, School of Medicine, San Francisco, CA, USA
| | - He Chen
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences, Oncological Sciences and Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Chengwei Zhang
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences, Oncological Sciences and Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Wenlei Ye
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
| | - Byron W Hayes
- Department of Pathology, Duke University Medical Center, Durham, NC, USA
| | - Jing Liu
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences, Oncological Sciences and Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ryan H Gumpper
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Brian J Bender
- Department of Pharmaceutical Sciences, University of California San Francisco, School of Medicine, San Francisco, CA, USA
| | - Samuel T Slocum
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Brian E Krumm
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Katherine Lansu
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - John D McCorvy
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Wesley K Kroeze
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Justin G English
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Jeffrey F DiBerto
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Reid H J Olsen
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Xi-Ping Huang
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Shicheng Zhang
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Yongfeng Liu
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Kuglae Kim
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Joel Karpiak
- Department of Pharmaceutical Sciences, University of California San Francisco, School of Medicine, San Francisco, CA, USA
| | - Lily Y Jan
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, San Francisco, CA, USA
| | - Soman N Abraham
- Department of Pathology, Duke University Medical Center, Durham, NC, USA
- Program in Emerging Infectious Diseases, Duke-National University of Singapore, Singapore, Singapore
| | - Jian Jin
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences, Oncological Sciences and Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Brian K Shoichet
- Department of Pharmaceutical Sciences, University of California San Francisco, School of Medicine, San Francisco, CA, USA.
| | - Jonathan F Fay
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA.
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA.
| |
Collapse
|
36
|
Guo CJ, Grabinski NS, Liu Q. Peripheral Mechanisms of Itch. J Invest Dermatol 2021; 142:31-41. [PMID: 34838258 DOI: 10.1016/j.jid.2021.10.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/15/2021] [Accepted: 10/26/2021] [Indexed: 12/30/2022]
Abstract
Itch is a universally experienced sensation, and chronic itch can be as diabolically debilitating as pain. Recent advances have not only identified the neuronal itch sensing circuitry, but also have uncovered the intricate interactions between skin and immune cells that work together with neurons to identify itch-inducing irritants. In this review, we will summarize the fundamental mechanisms of acute itch detection in the skin, as well as highlight the recent discoveries relating to this topic.
Collapse
Affiliation(s)
- Changxiong J Guo
- Center for the Study of Itch & Sensory Disorders, Department of Anesthesiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Nathaniel S Grabinski
- Center for the Study of Itch & Sensory Disorders, Department of Anesthesiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Qin Liu
- Center for the Study of Itch & Sensory Disorders, Department of Anesthesiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA.
| |
Collapse
|
37
|
Gurnani P, Miloh T, Chandar J, Landau DA, Hajjar F, Yosipovitch G. Systemic causes of non-dermatologic chronic pruritus in the pediatric population and their management: An unexplored area. Pediatr Dermatol 2021; 38:1051-1060. [PMID: 34515372 DOI: 10.1111/pde.14596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chronic pruritus associated with systemic diseases in the pediatric population has been infrequently addressed in the literature. This review focuses on chronic pruritus presenting without cutaneous manifestations. Common systemic etiologies include diseases with hepatic, renal, and hematologic origins. This encompasses several congenital liver disorders, end-stage renal disease (ESRD), and lymphoproliferative disorders such as Hodgkin's lymphoma. In this paper, an expert panel describes the clinical characteristics, pathophysiology, and therapeutic treatment ladders for chronic pruritus associated with the aforementioned systemic etiologies. Novel therapies are also reviewed. Our aim is to shed light on this unexplored area of pediatric dermatology and instigate further research.
Collapse
Affiliation(s)
- Pooja Gurnani
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery & Miami Itch Center, University of Miami, Miller School of Medicine, Miami, FL, USA.,Florida International University, Herbert Wertheim College of Medicine, Miami, FL, USA
| | - Tamir Miloh
- Pediatric Transplant Hepatology, Miami Transplant Institute, Jackson Health System, Miami, FL, USA
| | - Jayanthi Chandar
- Pediatric Kidney Transplantation, Miami Transplant Institute, Jackson Health System, Miami, FL, USA
| | | | - Fouad Hajjar
- AdventHealth For Children Pediatric Oncology and Hematology, Orlando, FL, USA
| | - Gil Yosipovitch
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery & Miami Itch Center, University of Miami, Miller School of Medicine, Miami, FL, USA
| |
Collapse
|
38
|
Misery L, Brenaut E, Pierre O, Le Garrec R, Gouin O, Lebonvallet N, Abasq-Thomas C, Talagas M, Le Gall-Ianotto C, Besner-Morin C, Fluhr JW, Leven C. Chronic itch: emerging treatments following new research concepts. Br J Pharmacol 2021; 178:4775-4791. [PMID: 34463358 DOI: 10.1111/bph.15672] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/20/2021] [Accepted: 08/24/2021] [Indexed: 11/29/2022] Open
Abstract
Until recently, itch pathophysiology was poorly understood and treatments were poorly effective in relieving itch. Current progress in our knowledge of the itch processing, the numerous mediators and receptors involved has led to a large variety of possible therapeutic pathways. Currently, inhibitors of IL-31, IL-4/13, NK1 receptors, opioids and cannabinoids, JAK, PDE4 or TRP are the main compounds involved in clinical trials. However, many new targets, such as Mas-related GPCRs and unexpected new pathways need to be also explored.
Collapse
Affiliation(s)
- Laurent Misery
- LIEN, Univ Brest, Brest, France.,Department of Dermatology, University Hospital of Brest, Brest, France
| | - Emilie Brenaut
- LIEN, Univ Brest, Brest, France.,Department of Dermatology, University Hospital of Brest, Brest, France
| | | | | | - Olivier Gouin
- LIEN, Univ Brest, Brest, France.,INSERM UMR 1163, Laboratory of Genetic Skin Diseases, Imagine Institute, Paris, France.,University of Paris, Paris, France
| | | | - Claire Abasq-Thomas
- LIEN, Univ Brest, Brest, France.,Department of Dermatology, University Hospital of Brest, Brest, France
| | - Matthieu Talagas
- LIEN, Univ Brest, Brest, France.,Department of Dermatology, University Hospital of Brest, Brest, France
| | | | - Catherine Besner-Morin
- LIEN, Univ Brest, Brest, France.,Department of Dermatology, University Hospital of Brest, Brest, France.,Division of Dermatology, McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada
| | - Joachim W Fluhr
- LIEN, Univ Brest, Brest, France.,Department of Dermatology, University Hospital of Brest, Brest, France.,Department of Dermatology, Charité Universitätsmedizin, Berlin, Germany
| | - Cyril Leven
- LIEN, Univ Brest, Brest, France.,EA3878, FCRIN INNOVTE, groupe d'étude thrombose Bretagne Occidentale, Brest, France.,Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France
| |
Collapse
|
39
|
Abstract
Pruritus (itch) is a debilitating symptom in liver diseases with cholestasis, which severely affects patients' quality of life. Limited treatment options are available for cholestatic itch, largely due to the incomplete understanding of the underlying molecular mechanisms. Several factors have been proposed as pruritogens for cholestatic itch, such as bile acids, bilirubin, lysophosphatidic acid, and endogenous opioids. Recently, two research groups independently identified Mas-related G protein-coupled receptor X4 (MRGPRX4) as a receptor for bile acids and bilirubin and demonstrated its likely role in cholestatic itch. This discovery not only opens new avenues for understanding the molecular mechanisms in cholestatic itch but provides a promising target for developing novel anti-itch treatments. In this review, we summarize the current theories and knowledge of cholestatic itch, emphasizing MRGPRX4 as a bile acid and bilirubin receptor mediating cholestatic itch in humans. We also discuss some future perspectives in cholestatic itch research.
Collapse
Affiliation(s)
- Huasheng Yu
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kirk Wangensteen
- Gastroenterology Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Tong Deng
- Department of Pathology, Sidney Sussex College, University of Cambridge, Cambridge, United Kingdom
| | - Yulong Li
- School of Life Sciences, Peking University, Beijing, China
| | - Wenqin Luo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| |
Collapse
|
40
|
Song MH, Shim WS. Lithocholic Acid Activates Mas-Related G Protein-Coupled Receptors, Contributing to Itch in Mice. Biomol Ther (Seoul) 2021; 30:38-47. [PMID: 34263729 PMCID: PMC8724838 DOI: 10.4062/biomolther.2021.059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/07/2021] [Accepted: 06/01/2021] [Indexed: 12/02/2022] Open
Abstract
The present study focused on lithocholic acid (LCA), a secondary bile acid that contributes to cholestatic pruritus. Although recent studies have found that LCA acts on MAS-related G protein-coupled receptor family member X4 (MRGPRX4) in humans, it is unclear which subtypes of MRGPRs are activated by LCA in mice since there is no precise ortholog of human MRGPRX4 in the mouse genome. Using calcium imaging, we found that LCA could activate mouse Mrgpra1 when transiently expressed in HEK293T cells. Moreover, LCA similarly activates mouse Mrgprb2. Importantly, LCA-induced responses showed dose-dependent effects through Mrgpra1 and Mrgprb2. Moreover, treatment with QWF (an antagonist of Mrgpra1 and Mrgprb2), YM254890 (Gαq inhibitor), and U73122 (an inhibitor of phospholipase C) significantly suppressed the LCA-induced responses, implying that the LCA-induced responses are indeed mediated by Mrgpra1 and Mrgprb2. Furthermore, LCA activated primary cultures of mouse sensory neurons and peritoneal mast cells, suggesting that Mrgpra1 and Mrgprb2 contribute to LCA-induced pruritus. However, acute injection of LCA did not induce noticeable differences in scratching behavior, implying that the pruritogenic role of LCA may be marginal in non-cholestatic conditions. In summary, the present study identified for the first time that LCA can activate Mrgpra1 and Mrgprb2. The current findings provide further insight into the similarities and differences between human and mouse MRGPR families, paving a way to understand the complex roles of these pruriceptors.
Collapse
Affiliation(s)
- Myung-Hyun Song
- College of Pharmacy, Gachon University, Incheon 21936, Republic of Korea
| | - Won-Sik Shim
- College of Pharmacy, Gachon University, Incheon 21936, Republic of Korea.,Gachon Institute of Pharmaceutical Sciences, Incheon 21936, Republic of Korea
| |
Collapse
|
41
|
Kong E, Wang H, Wang X, Zhang Y, Zhang J, Yu W, Feng X, Sun Y, Wu F. Bilirubin Induces Pain Desensitization in Cholestasis by Activating 5-Hydroxytryptamine 3A Receptor in Spinal Cord. Front Cell Dev Biol 2021; 9:605855. [PMID: 33869168 PMCID: PMC8047141 DOI: 10.3389/fcell.2021.605855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 03/15/2021] [Indexed: 11/13/2022] Open
Abstract
Background Cholestasis patients often suffer from pain desensitization, resulting in serious complications in perioperative period. This study was aim to investigate the mechanism of bilirubin in cholestasis mediating pain desensitization through 5-hydroxytryptamine 3A (5-HT3A ) receptor activation in spinal dorsal horn (SDH). Methods A cholestasis model was established by bile duct ligation (BDL) in rats. Pain thresholds of rats were measured after BDL or intrathecally injecting bilirubin in the presence or absence of agonist (mCPBG) and antagonists (ondansetron, bicuculline, or CGP55845). Expression of 5-HT3 receptors, and the affinity and binding mode of bilirubin to 5-HT3A receptor were determined. Effects of bilirubin on γ-aminobutyric acid (GABA) pathway and the interactions with 5-HT3A receptor were tested. Results Bilirubin was elevated significantly in both serum and CSF in BDL rats, accompanied with the up-regulation of pain thresholds. Both of 5-HT3A receptor and GABA A receptor antagonists could reverse the increased pain threshold in BDL rats. Further, 5-HT3A and GABA A receptor expressions were increased in BDL rats or intervention with bilirubin. Molecular docking suggested that bilirubin entered the hydrophobic pocket pre-formed in 5-HT3A receptor with potential hydrogen bonding. Bilirubin also increased GABA concentrations in CSF and GABAergic spontaneous inhibitory postsynaptic current in spinal cord, and directly induced inward currents in HEK293 cells which were overexpressed 5-HT3A receptor by lentivirus. Conclusion In conclusion, bilirubin induced pain desensitization in cholestasis by activating 5-HT3A receptor in spinal cord. The activation of 5-HT3A receptor might regulate pain threshold by acting on the GABA pathway.
Collapse
Affiliation(s)
- Erliang Kong
- Department of Anesthesiology, Shanghai Eastern Hepatobiliary Surgery Hospital, Naval Medical University, Shanghai, China.,Department of Anesthesiology, The 988th Hospital of Joint Logistic Support Force of PLA, Zhengzhou, China
| | - Hongqian Wang
- Department of Anesthesiology, Shanghai Eastern Hepatobiliary Surgery Hospital, Naval Medical University, Shanghai, China.,Department of Anesthesiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Xiaoqiang Wang
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Zhang
- Department of Anesthesiology, Zhejiang Province Zhoushan Hospital, Zhoushan, China
| | - Jinmin Zhang
- Department of Anesthesiology, Shanghai Eastern Hepatobiliary Surgery Hospital, Naval Medical University, Shanghai, China
| | - Weifeng Yu
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xudong Feng
- Department of Anesthesiology, The 988th Hospital of Joint Logistic Support Force of PLA, Zhengzhou, China
| | - Yuming Sun
- Department of Anesthesiology, Shanghai Eastern Hepatobiliary Surgery Hospital, Naval Medical University, Shanghai, China
| | - Feixiang Wu
- Department of Critical Care Medicine, Shanghai Eastern Hepatobiliary Surgery Hospital, Naval Medical University, Shanghai, China
| |
Collapse
|
42
|
Abstract
Pruritus is one of the most distressing symptoms in cholestatic patients. Plasma autotaxin (ATX) activity correlates with the severity of pruritus in cholestatic patients, but the pathophysiology is unclear. To study pruritus in mice, we measured scratch activity in cholestatic Atp8b1 mutant mice, a model for Progressive Familial Intrahepatic Cholestasis type 1, and wild type mice (WT) with alpha-naphthylisothiocyanate (ANIT)-induced cholestasis. To induce cholestasis, Atp8b1 mutant mice received a diet containing 0.1% cholic acid (CA) and WT mice were treated with ANIT. In these mice ATX was also overexpressed by transduction with AAV-ATX. Scratch activity was measured using an unbiased, electronic assay. Marked cholestasis was accomplished in both Atp8b1 mutant mice on a CA-supplemented diet and in ANIT-treatment in WT mice, but scratch activity was decreased rather than increased while plasma ATX activity was increased. Plasma ATX activity was further increased up to fivefold with AAV-ATX, but this did not induce scratch activity. In contrast to several reports two cholestatic mouse models did not display increased scratch activity as a measure of itch perception. Increasing plasma ATX activity by overexpression also did not lead to increased scratch activity in mice. This questions whether mice are suitable to study cholestatic itch.
Collapse
|
43
|
Langedijk JAGM, Beuers UH, Oude Elferink RPJ. Cholestasis-Associated Pruritus and Its Pruritogens. Front Med (Lausanne) 2021; 8:639674. [PMID: 33791327 PMCID: PMC8006388 DOI: 10.3389/fmed.2021.639674] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/12/2021] [Indexed: 12/17/2022] Open
Abstract
Pruritus is a debilitating symptom of various cholestatic disorders, including primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and inherited progressive familial intrahepatic cholestasis (PFIC). The molecular mechanisms leading to cholestasis-associated pruritus are still unresolved and the involved pruritogens are indecisive. As a consequence of pruritus, patients suffer from sleep deprivation, loss of daytime concentration, auto-mutilation and sometimes even suicidal ideations. Current guideline-approved therapy of cholestasis-associated pruritus includes stepwise administration of several medications, which may alleviate complaints in some, but not all affected patients. Therefore, also experimental therapeutic approaches are required to improve patients' quality of life. This article reviews the current state of research on pruritogens and their receptors, and shortly discusses the most recent experimental therapies.
Collapse
Affiliation(s)
- Jacqueline A G M Langedijk
- Amsterdam University Medical Centers, Tytgat Institute for Liver and Intestinal Research, Research Institute Amsterdam Gastroenterology, Endocrinology and Metabolism (AGEM), University of Amsterdam, Amsterdam, Netherlands
| | - Ulrich H Beuers
- Amsterdam University Medical Centers, Tytgat Institute for Liver and Intestinal Research, Research Institute Amsterdam Gastroenterology, Endocrinology and Metabolism (AGEM), University of Amsterdam, Amsterdam, Netherlands
| | - Ronald P J Oude Elferink
- Amsterdam University Medical Centers, Tytgat Institute for Liver and Intestinal Research, Research Institute Amsterdam Gastroenterology, Endocrinology and Metabolism (AGEM), University of Amsterdam, Amsterdam, Netherlands
| |
Collapse
|
44
|
Fiorucci S, Distrutti E, Carino A, Zampella A, Biagioli M. Bile acids and their receptors in metabolic disorders. Prog Lipid Res 2021; 82:101094. [PMID: 33636214 DOI: 10.1016/j.plipres.2021.101094] [Citation(s) in RCA: 110] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/03/2021] [Accepted: 02/12/2021] [Indexed: 02/08/2023]
Abstract
Bile acids are a large family of atypical steroids which exert their functions by binding to a family of ubiquitous cell membrane and nuclear receptors. There are two main bile acid activated receptors, FXR and GPBAR1, that are exclusively activated by bile acids, while other receptors CAR, LXRs, PXR, RORγT, S1PR2and VDR are activated by bile acids in addition to other more selective endogenous ligands. In the intestine, activation of FXR and GPBAR1 promotes the release of FGF15/19 and GLP1 which integrate their signaling with direct effects exerted by theother receptors in target tissues. This network is tuned in a time ordered manner by circadian rhythm and is critical for the regulation of metabolic process including autophagy, fast-to-feed transition, lipid and glucose metabolism, energy balance and immune responses. In the last decade FXR ligands have entered clinical trials but development of systemic FXR agonists has been proven challenging because their side effects including increased levels of cholesterol and Low Density Lipoproteins cholesterol (LDL-c) and reduced High-Density Lipoprotein cholesterol (HDL-c). In addition, pruritus has emerged as a common, dose related, side effect of FXR ligands. Intestinal-restricted FXR and GPBAR1 agonists and dual FXR/GPBAR1 agonists have been developed. Here we review the last decade in bile acids physiology and pharmacology.
Collapse
Affiliation(s)
- Stefano Fiorucci
- Dipartimento di Medicina e Chirurgia, Università di Perugia, Perugia, Italy.
| | - Eleonora Distrutti
- SC di Gastroenterologia ed Epatologia, Azienda Ospedaliera di Perugia, Perugia, Italy
| | - Adriana Carino
- Dipartimento di Medicina e Chirurgia, Università di Perugia, Perugia, Italy
| | - Angela Zampella
- Department of Pharmacy, University of Napoli, Federico II, Napoli, Italy
| | - Michele Biagioli
- Dipartimento di Medicina e Chirurgia, Università di Perugia, Perugia, Italy
| |
Collapse
|
45
|
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.
Collapse
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.
| |
Collapse
|
46
|
Creeden JF, Gordon DM, Stec DE, Hinds TD. Bilirubin as a metabolic hormone: the physiological relevance of low levels. Am J Physiol Endocrinol Metab 2021; 320:E191-E207. [PMID: 33284088 PMCID: PMC8260361 DOI: 10.1152/ajpendo.00405.2020] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Recent research on bilirubin, a historically well-known waste product of heme catabolism, suggests an entirely new function as a metabolic hormone that drives gene transcription by nuclear receptors. Studies are now revealing that low plasma bilirubin levels, defined as "hypobilirubinemia," are a possible new pathology analogous to the other end of the spectrum of extreme hyperbilirubinemia seen in patients with jaundice and liver dysfunction. Hypobilirubinemia is most commonly seen in patients with metabolic dysfunction, which may lead to cardiovascular complications and possibly stroke. We address the clinical significance of low bilirubin levels. A better understanding of bilirubin's hormonal function may explain why hypobilirubinemia might be deleterious. We present mechanisms by which bilirubin may be protective at mildly elevated levels and research directions that could generate treatment possibilities for patients with hypobilirubinemia, such as targeting of pathways that regulate its production or turnover or the newly designed bilirubin nanoparticles. Our review here calls for a shift in the perspective of an old molecule that could benefit millions of patients with hypobilirubinemia.
Collapse
Affiliation(s)
- Justin F Creeden
- Department of Neurosciences, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - Darren M Gordon
- Department of Neurosciences, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - David E Stec
- Department of Physiology & Biophysics, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Terry D Hinds
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, Kentucky
| |
Collapse
|
47
|
Automated detection of mouse scratching behaviour using convolutional recurrent neural network. Sci Rep 2021; 11:658. [PMID: 33436724 PMCID: PMC7803777 DOI: 10.1038/s41598-020-79965-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/07/2020] [Indexed: 02/03/2023] Open
Abstract
Scratching is one of the most important behaviours in experimental animals because it can reflect itching and/or psychological stress. Here, we aimed to establish a novel method to detect scratching using deep neural network. Scratching was elicited by injecting a chemical pruritogen lysophosphatidic acid to the back of a mouse, and behaviour was recorded using a standard handy camera. Images showing differences between two consecutive frames in each video were generated, and each frame was manually labelled as showing scratching behaviour or not. Next, a convolutional recurrent neural network (CRNN), composed of sequential convolution, recurrent, and fully connected blocks, was constructed. The CRNN was trained using the manually labelled images and then evaluated for accuracy using a first-look dataset. Sensitivity and positive predictive rates reached 81.6% and 87.9%, respectively. The predicted number and durations of scratching events correlated with those of the human observation. The trained CRNN could also successfully detect scratching in the hapten-induced atopic dermatitis mouse model (sensitivity, 94.8%; positive predictive rate, 82.1%). In conclusion, we established a novel scratching detection method using CRNN and showed that it can be used to study disease models.
Collapse
|
48
|
Steele HR, Han L. The signaling pathway and polymorphisms of Mrgprs. Neurosci Lett 2020; 744:135562. [PMID: 33388356 DOI: 10.1016/j.neulet.2020.135562] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 12/31/2022]
Abstract
Mas-related G protein-coupled receptors (Mrgprs) are a family of receptors implicated in a diverse array of human diseases. Since their discovery in 2001, great progress has been made in determining their relation to human disease. Vital for Mrgprs therapeutic efforts across all disease disciplines is a thorough understanding of Mrgprs signal transduction pathways and polymorphisms, as these offer insights into new drug candidates, existing discrepancies in drug response, and differences in disease susceptibility. In this review, we discuss the current state of knowledge regarding Mrgprs signaling pathways and polymorphisms.
Collapse
Affiliation(s)
- Haley R Steele
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Liang Han
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States.
| |
Collapse
|
49
|
Substance P Release by Sensory Neurons Triggers Dendritic Cell Migration and Initiates the Type-2 Immune Response to Allergens. Immunity 2020; 53:1063-1077.e7. [PMID: 33098765 DOI: 10.1016/j.immuni.2020.10.001] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/21/2020] [Accepted: 09/30/2020] [Indexed: 11/20/2022]
Abstract
Dendritic cells (DCs) of the cDC2 lineage initiate allergic immunity and in the dermis are marked by their expression of CD301b. CD301b+ dermal DCs respond to allergens encountered in vivo, but not in vitro. This suggests that another cell in the dermis may sense allergens and relay that information to activate and induce the migration of CD301b+ DCs to the draining lymph node (dLN). Using a model of cutaneous allergen exposure, we show that allergens directly activated TRPV1+ sensory neurons leading to itch and pain behaviors. Allergen-activated sensory neurons released the neuropeptide Substance P, which stimulated proximally located CD301b+ DCs through the Mas-related G-protein coupled receptor member A1 (MRGPRA1). Substance P induced CD301b+ DC migration to the dLN where they initiated T helper-2 cell differentiation. Thus, sensory neurons act as primary sensors of allergens, linking exposure to activation of allergic-skewing DCs and the initiation of an allergic immune response.
Collapse
|
50
|
Meixiong J, Dong X, Weng HJ. Neuropathic Itch. Cells 2020; 9:cells9102263. [PMID: 33050211 PMCID: PMC7601786 DOI: 10.3390/cells9102263] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/12/2022] Open
Abstract
Neurologic insults as varied as inflammation, stroke, and fibromyalgia elicit neuropathic pain and itch. Noxious sensation results when aberrantly increased afferent signaling reaches percept-forming cortical neurons and can occur due to increased sensory signaling, decreased inhibitory signaling, or a combination of both processes. To treat these symptoms, detailed knowledge of sensory transmission, from innervated end organ to cortex, is required. Molecular, genetic, and behavioral dissection of itch in animals and patients has improved understanding of the receptors, cells, and circuits involved. In this review, we will discuss neuropathic itch with a focus on the itch-specific circuit.
Collapse
Affiliation(s)
- James Meixiong
- Solomon H. Snyder Department of Neuroscience and Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
| | - Xinzhong Dong
- Solomon H. Snyder Department of Neuroscience, Department of Dermatology, and Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hao-Jui Weng
- Department of Dermatology, Taipei Medical University-Shuang Ho Hospital, New Taipei City 23561, Taiwan
- Department of Dermatology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
- Correspondence:
| |
Collapse
|