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Balzulat A, Zhu WF, Flauaus C, Hernandez‐Olmos V, Heering J, Sethumadhavan S, Dubiel M, Frank A, Menge A, Hebchen M, Metzner K, Lu R, Lukowski R, Ruth P, Knapp S, Müller S, Steinhilber D, Hänelt I, Stark H, Proschak E, Schmidtko A. Discovery of a Small Molecule Activator of Slack (Kcnt1) Potassium Channels That Significantly Reduces Scratching in Mouse Models of Histamine-Independent and Chronic Itch. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2307237. [PMID: 38350720 PMCID: PMC11022729 DOI: 10.1002/advs.202307237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/15/2024] [Indexed: 02/15/2024]
Abstract
Various disorders are accompanied by histamine-independent itching, which is often resistant to the currently available therapies. Here, it is reported that the pharmacological activation of Slack (Kcnt1, KNa1.1), a potassium channel highly expressed in itch-sensitive sensory neurons, has therapeutic potential for the treatment of itching. Based on the Slack-activating antipsychotic drug, loxapine, a series of new derivatives with improved pharmacodynamic and pharmacokinetic profiles is designed that enables to validate Slack as a pharmacological target in vivo. One of these new Slack activators, compound 6, exhibits negligible dopamine D2 and D3 receptor binding, unlike loxapine. Notably, compound 6 displays potent on-target antipruritic activity in multiple mouse models of acute histamine-independent and chronic itch without motor side effects. These properties make compound 6 a lead molecule for the development of new antipruritic therapies targeting Slack.
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Affiliation(s)
- Annika Balzulat
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - W. Felix Zhu
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Cathrin Flauaus
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Victor Hernandez‐Olmos
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMPTheodor‐Stern‐Kai 760596Frankfurt am MainGermany
| | - Jan Heering
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMPTheodor‐Stern‐Kai 760596Frankfurt am MainGermany
| | - Sunesh Sethumadhavan
- Institute of BiochemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Mariam Dubiel
- Institute of Pharmaceutical and Medicinal ChemistryHeinrich Heine University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Annika Frank
- Institute of Pharmaceutical and Medicinal ChemistryHeinrich Heine University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Amelie Menge
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Structural Genomics Consortium (SGC)Buchmann Institute for Molecular Life SciencesGoethe University FrankfurtMax‐von‐Laue‐Str. 1560438Frankfurt am MainGermany
| | - Maureen Hebchen
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Katharina Metzner
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Ruirui Lu
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Robert Lukowski
- Department of PharmacologyToxicology and Clinical PharmacyInstitute of Pharmacy University of TübingenAuf der Morgenstelle 872076TübingenGermany
| | - Peter Ruth
- Department of PharmacologyToxicology and Clinical PharmacyInstitute of Pharmacy University of TübingenAuf der Morgenstelle 872076TübingenGermany
| | - Stefan Knapp
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Structural Genomics Consortium (SGC)Buchmann Institute for Molecular Life SciencesGoethe University FrankfurtMax‐von‐Laue‐Str. 1560438Frankfurt am MainGermany
| | - Susanne Müller
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Structural Genomics Consortium (SGC)Buchmann Institute for Molecular Life SciencesGoethe University FrankfurtMax‐von‐Laue‐Str. 1560438Frankfurt am MainGermany
| | - Dieter Steinhilber
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMPTheodor‐Stern‐Kai 760596Frankfurt am MainGermany
| | - Inga Hänelt
- Institute of BiochemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Holger Stark
- Institute of Pharmaceutical and Medicinal ChemistryHeinrich Heine University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Ewgenij Proschak
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMPTheodor‐Stern‐Kai 760596Frankfurt am MainGermany
| | - Achim Schmidtko
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
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Green PG, Levine JD. A novel anti-pruritic: Topical co-administration of high molecular weight hyaluronan (HMWH) with protamine, a transdermal transport enhancer. Mol Pain 2024; 20:17448069241254455. [PMID: 38728068 PMCID: PMC11088296 DOI: 10.1177/17448069241254455] [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: 04/02/2024] [Revised: 05/09/2024] [Accepted: 04/25/2024] [Indexed: 05/12/2024] Open
Abstract
Pruritis, the sensation of itch, is produced by multiple substances, exogenous and endogenous, that sensitizes specialized sensory neurons (pruriceptors and pruri-nociceptors). Unfortunately, many patients with acute and chronic pruritis obtain only partial relief when treated with currently available treatment modalities. We recently demonstrated that the topical application of high molecular weight hyaluronan (HMWH), when combined with vehicles containing transdermal transport enhancers, produce potent long-lasting reversal of nociceptor sensitization associated with inflammatory and neuropathic pain. In the present experiments we tested the hypothesis that the topical formulation of HMWH with protamine, a transdermal transport enhancer, can also attenuate pruritis. We report that this topical formulation of HMWH markedly attenuates scratching behavior at the nape of the neck induced by serotonin (5-hydroxytryptamine, 5-HT), in male and female rats. Our results support the hypothesis that topical HMWH in a transdermal transport enhancer vehicle is a strong anti-pruritic.
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Affiliation(s)
- Paul G Green
- Department of Oral & Maxillofacial Surgery, and UCSF Pain and Addiction Research Center, University of California at San Francisco, San Francisco, CA, USA
- Department of Preventative & Restorative Dental Sciences, and Division of Neuroscience, University of California at San Francisco, San Francisco, CA, USA
| | - Jon D Levine
- Department of Oral & Maxillofacial Surgery, and UCSF Pain and Addiction Research Center, University of California at San Francisco, San Francisco, CA, USA
- Department of Medicine, and Division of Neuroscience, University of California at San Francisco, San Francisco, CA, USA
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Nagata N, Suzuki T, Takenouchi S, Kobayashi K, Murata T. Alleviation of allergic conjunctivitis by (±)5(6)-dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic acid in mice. Front Pharmacol 2023; 14:1217397. [PMID: 37822881 PMCID: PMC10562701 DOI: 10.3389/fphar.2023.1217397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 09/06/2023] [Indexed: 10/13/2023] Open
Abstract
Background: Allergic conjunctivitis (AC) is a common ophthalmologic disorder that causes symptoms that often reduces a patient's quality of life (QOL). We investigated the effects of the eicosapentaenoic acid metabolite (±)5(6)-dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic acid ((±)5(6)-DiHETE) on AC using a mouse model. Methods: BALB/c mice were sensitized with two injections of short ragweed pollen in alum, challenged fifth with pollen in eyedrops. The clinical signs and tear volume were evaluated at 15 min after the final challenge. Histamine-induced ocular inflammation model was prepared by instilling histamine onto the surface of the eye. Fifteen minutes after histamine application, tear volume was measured using the Schirmer tear test. Miles assay was performed to investigate vascular permeability. To cause scratching behavior 10 μg of serotonin was injected in the cheek. Results: Repeated topical application of pollen induced conjunctivitis, accompanied by eyelid edema and tearing in mice. Pollen application typically degranulates mast cells and recruits eosinophils to the conjunctiva. Intraperitoneal administration of 300 μg/kg of (±)5(6)-DiHETE significantly inhibited pollen-induced symptoms. The administration of (±)5(6)-DiHETE also attenuated mast cell degranulation and eosinophil infiltration into the conjunctiva. To assess the effects of (±)5(6)-DiHETE on the downstream pathway of mast cell activation in AC, we used a histamine-induced ocular inflammation model. Topical application of 4 μg/eye histamine caused eyelid edema and tearing and increased vascular permeability, as indicated by Evans blue dye extravasation. Intraperitoneal administration of 300 μg/kg or topical administration of 1 μg/eye (±)5(6)-DiHETE inhibited histamine-induced manifestations. Finally, we assessed the effects of (±)5(6)-DiHETE on itching. An intradermal injection of 10 μg serotonin in the cheek caused scratching behavior in mice. Intraperitoneal administration of 300 μg/kg (±)5(6)-DiHETE significantly inhibited serotonin-induced scratching. Conclusion: Thus, (±)5(6)-DiHETE treatment broadly suppressed AC pathology and could be a novel treatment option for AC.
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Affiliation(s)
- Nanae Nagata
- Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Tomoka Suzuki
- Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Shinya Takenouchi
- Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Koji Kobayashi
- Food and Animal Systemics, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takahisa Murata
- Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Food and Animal Systemics, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Veterinary Pharmacology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Gazerani P. How Does Botulinum Toxin Inhibit Itch? Toxins (Basel) 2022; 14:701. [PMID: 36287970 PMCID: PMC9610088 DOI: 10.3390/toxins14100701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/06/2022] [Accepted: 10/10/2022] [Indexed: 12/04/2022] Open
Abstract
Two decades after reports of the anti-pruritic effects of botulinum neurotoxins (BoNTs), there is still no approved product for the anti-itch indication of BoNTs, and most clinical case reports still focus on the off-label use of BoNTs for various itchy conditions. Few randomized clinical trials have been conducted with controversial results, and the beneficial effects of BoNTs against itch are mainly based on case studies and case series. These studies are valuable in presenting the potential application of BoNTs in chronic pruritic conditions, but due to the nature of these studies, they are categorized as providing lower levels of evidence or lower grades of recommendation. To obtain approval for the anti-pruritic indication of BoNTs, higher levels of evidence are required, which can be achieved through conducting large-scale and well-designed studies with proper control groups and established careful and reliable primary and secondary outcomes. In addition to clinical evidence, presenting the mechanism-based antipruritic action of BoNTs can potentially strengthen, accelerate, and facilitate the current efforts towards further investments in accelerating the field towards the potential approval of BoNTs for itchy conditions. This review, therefore, aimed to provide the state-of-the-art mechanisms underlying the anti-itch effect of BoNTs from basic studies that resemble various clinical conditions with itch as a hallmark. Evidence of the neuronal, glial, and immune modulatory actions of BoNTs in reducing the transmission of itch are presented, and future potential directions are outlined.
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Affiliation(s)
- Parisa Gazerani
- Department of Life Sciences and Health, Faculty of Health Sciences, Oslo Metropolitan University, 0130 Oslo, Norway; or
- Department of Health Science and Technology, Faculty of Medicine, Aalborg University, 9220 Aalborg East, Denmark
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Zhang Q, Li T, Niu J, Xiao J, Zhang M, Zhang R, Chen D, Shi Y, Zhang X, Hu X, Yu B, Feng J, Fang Q. Inhibitory effects of antibiotic-induced gut microbiota depletion on acute itch behavior in mice. Brain Res Bull 2022; 190:50-61. [PMID: 36126873 DOI: 10.1016/j.brainresbull.2022.09.014] [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: 05/13/2022] [Revised: 09/07/2022] [Accepted: 09/16/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND The gut microbiota is known to be associated with the regulation of many neurological diseases and behaviors, including chronic pain. However, it is unclear whether the gut microbiota is critical to the itch sensation. In this study, we investigated the effects of gut microbiota depletion on acute itch. METHODS First, an antibiotic cocktail was orally administered to deplete the gut microbiota in male C57BL/6 mice. Then, pruritogens were intradermally injected to induce acute itch behavior. In addition, antibiotic-treated mice received transplantation of fecal microbiota from untreated mice, followed by tests for acute itch. The changes in c-Fos expression in trigeminal ganglia (TG) neurons were also investigated by immunofluorescence staining. RESULTS Our results indicated that chronic antibiotic treatment significantly reduced the diversity and richness of the gut microbiota of mice. Compared to vehicle-treated mice, antibiotic-treated mice showed reductions in acute itch behavior induced by compound 48/80, chloroquine (CQ), and serotonin (5-HT), respectively. Moreover, repositioning of microbiota reversed the reductions in acute itch behavior in antibiotic-treated mice. In addition, immunofluorescence staining revealed that antibiotic-treated mice displayed decreased c-Fos expression in ipsilateral TG compared to controls. CONCLUSIONS Our study, for the first time, discovered that antibiotic-induced gut microbiota depletion could reduce acute itch behavior, which may be connected with decreased TG neuronal activity.
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Affiliation(s)
- Qinqin Zhang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Tingting Li
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Jiandong Niu
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Jian Xiao
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Mengna Zhang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Run Zhang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Dan Chen
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Yonghang Shi
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Xiaodi Zhang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Xuanran Hu
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Bowen Yu
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
| | - Jie Feng
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China.
| | - Quan Fang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China.
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Critical Players and Therapeutic Targets in Chronic Itch. Int J Mol Sci 2022; 23:ijms23179935. [PMID: 36077340 PMCID: PMC9456029 DOI: 10.3390/ijms23179935] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/28/2022] [Accepted: 08/29/2022] [Indexed: 12/04/2022] Open
Abstract
Chronic itch is one of the most prominent clinical characteristics of diverse systematic diseases. It is a devastating sensation in pathological diseases. Despite its importance, there are no FDA-labelled drugs specifically geared toward chronic itch. The associated complex pathogenesis and diverse causes escalate chronic itch to being one of the top challenges in healthcare. Humanized antibodies against IL-13, IL-4, and IL-31 proved effective in treatment of itch-associated atopic dermatitis but remain to be validated in chronic itch. There are still no satisfactory anti-itch therapeutics available toward itch-related neuropeptides including GRP, BNP, SST, CGRP, and SP. The newly identified potential itch targets including OSM, NMB, glutamate, periostin, and Serpin E1 have opened new avenues for therapeutic development. Proof-of-principle studies have been successfully performed on antagonists against these proteins and their receptors in itch treatment in animal models. Their translational interventions in humans need to be evaluated. It is of great importance to summarize and compare the newly emerging knowledge on chronic itch and its pathways to promote the development of novel anti-itch therapeutics. The goal of this review is to analyze the different physiologies and pathophysiologies of itch mediators, whilst assessing their suitability as new targets and discussing future therapeutic development.
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Toyama S, Tominaga M, Takamori K. Treatment Options for Troublesome Itch. Pharmaceuticals (Basel) 2022; 15:1022. [PMID: 36015170 PMCID: PMC9412524 DOI: 10.3390/ph15081022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/16/2022] [Accepted: 08/16/2022] [Indexed: 01/20/2023] Open
Abstract
Itch (or pruritus) is an unpleasant sensation, inducing the desire to scratch. It is also a major and distressing symptom of many skin and systemic diseases. The involvement of histamine, which is a major itch mediator, has been extensively examined. Recent studies suggest that histamine-independent pathways may play roles in chronic itch. Therefore, antihistamines are not always effective in the treatment of patients with chronic itch. The development of biologics and κ-opioid receptor (KOR) agonists has contributed to advances in the treatment of itch; however, since biologics are expensive for patients to purchase, some patients may limit or discontinue their use of these agents. Furthermore, KOR agonists need to be prescribed with caution due to risks of side effects in the central nervous system. Janus kinase (JAK) inhibitors are sometimes associated with side effects, such as infection. In this review, we summarize antidepressants, antineuralgics, cyclosporine A, antibiotics, crotamiton, phosphodiesterase 4 inhibitor, botulinum toxin type A, herbal medicines, phototherapy, and acupuncture therapy as itch treatment options other than antihistamines, biologics, opioids, and JAK inhibitors; we also explain their underlying mechanisms of action.
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Affiliation(s)
- Sumika Toyama
- Juntendo Itch Research Center (JIRC), Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Urayasu 279-0021, Chiba, Japan
| | - Mitsutoshi Tominaga
- Juntendo Itch Research Center (JIRC), Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Urayasu 279-0021, Chiba, Japan
- Anti-Aging Skin Research Laboratory, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Urayasu 279-0021, Chiba, Japan
| | - Kenji Takamori
- Juntendo Itch Research Center (JIRC), Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Urayasu 279-0021, Chiba, Japan
- Anti-Aging Skin Research Laboratory, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Urayasu 279-0021, Chiba, Japan
- Department of Dermatology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu 279-0021, Chiba, Japan
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Hu L, Jiang GY, Wang YP, Hu ZB, Zhou BY, Zhang L, Song NN, Huang Y, Chai GD, Chen JY, Lang B, Xu L, Liu JL, Li Y, Wang QX, Ding YQ. The role of PTEN in primary sensory neurons in processing itch and thermal information in mice. Cell Rep 2022; 39:110724. [PMID: 35443189 DOI: 10.1016/j.celrep.2022.110724] [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: 08/26/2021] [Revised: 03/03/2022] [Accepted: 03/30/2022] [Indexed: 12/01/2022] Open
Abstract
PTEN is known as a tumor suppressor and plays essential roles in brain development. Here, we report that PTEN in primary sensory neurons is involved in processing itch and thermal information in adult mice. Deletion of PTEN in the dorsal root ganglia (DRG) is achieved in adult Drg11-CreER: PTENflox/flox (PTEN CKO) mice with oral administration of tamoxifen, and CKO mice develop pathological itch and elevated itch responses on exposure to various pruritogens. PTEN deletion leads to ectopic expression of TRPV1 and MrgprA3 in IB4+ non-peptidergic DRG neurons, and the TRPV1 is responsive to capsaicin. Importantly, the elevated itch responses are no longer present in Drg11-CreER: PTENflox/flox: TRPV1flox/flox (PTEN: TRPV1 dCKO) mice. In addition, thermal stimulation is enhanced in PTEN CKO mice but blunted in dCKO mice. PTEN-involved regulation of itch-related gene expression in DRG neurons provides insights for understanding molecular mechanism of itch and thermal sensation at the spinal level.
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Affiliation(s)
- Ling Hu
- Department of Laboratory Animal Science, Fudan University, Shanghai 200032, China; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China; Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, and Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai 200092, China
| | - Guan-Yu Jiang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, and Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai 200092, China
| | - Ying-Ping Wang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Institute of Medical Sciences, Shanghai JiaoTong University School of Medicine, Shanghai 200025, China
| | - Zhi-Bin Hu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Bing-Yao Zhou
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Lei Zhang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, and Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai 200092, China
| | - Ning-Ning Song
- Department of Laboratory Animal Science, Fudan University, Shanghai 200032, China; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Ying Huang
- Department of Laboratory Animal Science, Fudan University, Shanghai 200032, China
| | - Guo-Dong Chai
- Department of Anesthesiology, East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Jia-Yin Chen
- Department of Laboratory Animal Science, Fudan University, Shanghai 200032, China; Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, and Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai 200092, China
| | - Bing Lang
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Lin Xu
- Laboratory of Learning and Memory, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Jun-Ling Liu
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Institute of Medical Sciences, Shanghai JiaoTong University School of Medicine, Shanghai 200025, China
| | - Yong Li
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Institute of Medical Sciences, Shanghai JiaoTong University School of Medicine, Shanghai 200025, China
| | - Qing-Xiu Wang
- Department of Anesthesiology, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
| | - Yu-Qiang Ding
- Department of Laboratory Animal Science, Fudan University, Shanghai 200032, China; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China; Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, and Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai 200092, China.
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Tang Y, Cheng S, Wang J, Jin Y, Yang H, Lin Q, Xu S, Hui L, Yin Q, Yang Y, Wu X. Acupuncture for the Treatment of Itch: Peripheral and Central Mechanisms. Front Neurosci 2022; 15:786892. [PMID: 35431769 PMCID: PMC9005788 DOI: 10.3389/fnins.2021.786892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/13/2021] [Indexed: 11/21/2022] Open
Abstract
Despite the widespread clinical use of acupuncture in the treatment of pruritus caused by psoriasis, urticaria, uremic, and other diseases, insights into the mechanism of action of acupuncture are still emerging. For the above reasons, a beneficial effect of acupuncture on pruritus was not recommended or reported in recent clinical practice guidelines. Acupuncture is a kind of physical stimulation, which has the characteristics of multi-channel and multi-target effects. The biomechanical stimulation signal of acupuncture needling can be transformed into bioelectric and chemical signals; interfere with kinds of cells and nerve fibers in the skin and muscle; alter signaling pathways and transcriptional activity of cells, mediators, and receptors; and result in inhibition of peripheral and central transmission of pruritus. Available mechanistic data give insights into the biological regulation potency of acupuncture for pruritus and provide a basis for more in-depth and comprehensive mechanism research.
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What If Not All Metabolites from the Uremic Toxin Generating Pathways Are Toxic? A Hypothesis. Toxins (Basel) 2022; 14:toxins14030221. [PMID: 35324718 PMCID: PMC8953523 DOI: 10.3390/toxins14030221] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/02/2022] [Accepted: 03/14/2022] [Indexed: 12/21/2022] Open
Abstract
The topic of uremic toxicity has received broad attention from the nephrological community over the past few decades. An aspect that is much less often considered is the possibility that the metabolic pathways that generate uremic toxins also may produce molecules that benefit body functions. Here, we discuss this dualism based on the example of tryptophan-derived metabolites, which comprise elements that are mainly toxic, such as indoxyl sulfate, kynurenine and kynurenic acid, but also beneficial compounds, such as indole, melatonin and indole-3-propionic acid, and ambivalent (beneficial for some aspects and harmful for others) compounds such as serotonin. This dualism can also be perceived at the level of the main receptor of the tryptophan-derived metabolites, the aryl hydrocarbon receptor (AHR), which has also been linked to both harm and benefit. We hypothesize that these beneficial effects are the reason why uremic toxin generation remained preserved throughout evolution. This duality is also not unique for the tryptophan-derived metabolites, and in this broader context we discuss the remote sensing and signaling theory (RSST). The RSST proposes that transporters (e.g., organic anion transporter 1—OAT1; ATP-binding cassette transporter G—ABCG2) and drug metabolizing enzymes form a large network of proteins interacting to promote small molecule remote communication at the inter-organ (e.g., gut–liver–heart–brain–kidney) and inter-organismal (e.g., gut microbe–host) levels. These small molecules include gut microbe-derived uremic toxins as well as beneficial molecules such as those discussed here. We emphasize that this positive side of uremic metabolite production needs more attention, and that this dualism especially needs to be considered when assessing and conceiving of therapeutic interventions. These homeostatic considerations are central to the RSST and suggest that interventions be aimed at preserving or restoring the balance between positive and negative components rather than eliminating them all without distinction.
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11
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Shirolkar P, Mishra SK. Role of TRP ion channels in pruritus. Neurosci Lett 2022; 768:136379. [PMID: 34861341 PMCID: PMC8755431 DOI: 10.1016/j.neulet.2021.136379] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 01/21/2023]
Abstract
The transient receptor potential (TRP) channel superfamily responds to various physical, chemical, and environmental stimuli including the detection of sensations both harmful and non-harmful. Among these sensations is pruritus, or itch. There are at least 27 different TRP channels and about six of them are involved in pruriception. The function of these six receptors is primarily seen in the skin and the dorsal root ganglia. Identification and biological insights provided by these receptors in pruriception is important for human health as mutations and activations of many of these channels cause discomfort and disease. This review will focus on involvement of TRP channels in pruriception that may render these channels as the targets of many antagonistic topical medications, which may help patients' better cope with the pruritus that results from various cutaneous and systemic diseases.
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Affiliation(s)
- Parth Shirolkar
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Santosh K. Mishra
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA,Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA,The WM Keck Behavioral Center, North Carolina State University, Raleigh, NC, USA,Program in Genetics, North Carolina State University, Raleigh, NC, USA
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12
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Toyama S, Tominaga M, Takamori K. Connections between Immune-Derived Mediators and Sensory Nerves for Itch Sensation. Int J Mol Sci 2021; 22:12365. [PMID: 34830245 PMCID: PMC8624544 DOI: 10.3390/ijms222212365] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/09/2021] [Accepted: 11/15/2021] [Indexed: 12/28/2022] Open
Abstract
Although histamine is a well-known itch mediator, histamine H1-receptor blockers often lack efficacy in chronic itch. Recent molecular and cellular based studies have shown that non-histaminergic mediators, such as proteases, neuropeptides and cytokines, along with their cognate receptors, are involved in evocation and modulation of itch sensation. Many of these molecules are produced and secreted by immune cells, which act on sensory nerve fibers distributed in the skin to cause itching and sensitization. This understanding of the connections between immune cell-derived mediators and sensory nerve fibers has led to the development of new treatments for itch. This review summarizes current knowledge of immune cell-derived itch mediators and neuronal response mechanisms, and discusses therapeutic agents that target these systems.
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Affiliation(s)
- Sumika Toyama
- Juntendo Itch Research Center (JIRC), Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Chiba 279-0021, Japan; (S.T.); (M.T.)
| | - Mitsutoshi Tominaga
- Juntendo Itch Research Center (JIRC), Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Chiba 279-0021, Japan; (S.T.); (M.T.)
- Anti-Aging Skin Research Laboratory, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Chiba 279-0021, Japan
| | - Kenji Takamori
- Juntendo Itch Research Center (JIRC), Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Chiba 279-0021, Japan; (S.T.); (M.T.)
- Anti-Aging Skin Research Laboratory, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Chiba 279-0021, Japan
- Department of Dermatology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Chiba 279-0021, Japan
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13
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Sanjel B, Kim BH, Song MH, Carstens E, Shim WS. Glucosylsphingosine evokes pruritus via activation of 5-HT 2A receptor and TRPV4 in sensory neurons. Br J Pharmacol 2021; 179:2193-2207. [PMID: 34766332 DOI: 10.1111/bph.15733] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND AND PURPOSE Glucosylsphingosine (GS), an endogenous sphingolipid, is highly accumulated in the epidermis of patients with atopic dermatitis (AD) due to abnormal ceramide metabolism. More importantly, GS can evoke scratching behaviors. However, the precise molecular mechanism by which GS induces pruritus has been elusive. Thus, the present study aimed to elucidate the molecular signaling pathway of GS, especially at the peripheral sensory neuronal levels. EXPERIMENTAL APPROACH Calcium imaging was used to investigate the responses of HEK293T cells or mouse dorsal root ganglion (DRG) neurons to application of GS. Scratching behavior tests were also performed with wild-type and Trpv4 knockout mice. KEY RESULTS GS activated DRG neurons in a manner involving both the 5-HT2A receptor and TRPV4. Furthermore, GS-induced responses were significantly suppressed by various inhibitors, including ketanserin (5-HT2A receptor antagonist), YM254890 (Gαq/11 inhibitor), gallein (Gβγ complex inhibitor), U73122 (phospholipase C inhibitor), bisindolylmaleimide I (PKC inhibitor), and HC067047 (TRPV4 antagonist). Moreover, DRG neurons from Trpv4 knockout mice exhibited significantly reduced responses to GS. Additionally, GS-evoked scratching behaviors were greatly decreased by pretreatment with inhibitors of either 5-HT2A receptor or TRPV4. As expected, GS-evoked scratching behavior was also significantly decreased in Trpv4 knockout mice. CONCLUSION AND IMPLICATIONS Overall, the present study provides evidence for a novel molecular signaling pathway for GS-evoked pruritus, which utilizes both 5-HT2A receptor and TRPV4 in mouse sensory neurons. Considering the high accumulation of GS in the epidermis of patients with AD, GS could be another pruritogen in patients with AD.
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Affiliation(s)
- Babina Sanjel
- College of Pharmacy, Gachon University, Incheon, Republic of Korea.,Gachon Institute of Pharmaceutical Sciences, Incheon, Republic of Korea
| | - Bo-Hyun Kim
- College of Pharmacy, Gachon University, Incheon, Republic of Korea.,Gachon Institute of Pharmaceutical Sciences, Incheon, Republic of Korea
| | - Myung-Hyun Song
- College of Pharmacy, Gachon University, Incheon, Republic of Korea
| | - Earl Carstens
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California, USA
| | - Won-Sik Shim
- College of Pharmacy, Gachon University, Incheon, Republic of Korea.,Gachon Institute of Pharmaceutical Sciences, Incheon, Republic of Korea
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14
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Kwiatkowska D, Reich A. Role of Mast Cells in the Pathogenesis of Pruritus in Mastocytosis. Acta Derm Venereol 2021; 101:adv00583. [PMID: 34642766 DOI: 10.2340/actadv.v101.350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Pruritus can be defined as an unpleasant sensation that evokes a desire to scratch and significantly impairs patients' quality of life. Pruritus is widely observed in many dermatoses, including mastocytosis, a rare disease characterized by abnormal accumulation of mast cells, which can involve skin, bone marrow, and other organs. Increasing evidence highlights the role of mast cells in neurogenic inflammation and itching. Mast cells release various pruritogenic mediators, initiating subsequent mutual communication with specific nociceptors on sensory nerve fibres. Among important mediators released by mast cells that induce pruritus, one can distinguish histamine, serotonin, proteases, as well as various cytokines. During neuronal-induced inflammation, mast cells may respond to numerous mediators, including neuropeptides, such as substance P, neurokinin A, calcitonin gene-related peptide, endothelin 1, and nerve growth factor. Currently, treatment of pruritus in mastocytosis is focused on alleviating the effects of mediators secreted by mast cells. However, a deeper understanding of the intricacies of the neurobiology of this disease could help to provide better treatment options for patients.
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Affiliation(s)
| | - Adam Reich
- Department of Dermatology, University of Rzeszow, Ul. Szopena 2, PL-35-055 Rzeszów, Poland.
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15
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Wimalasena NK, Milner G, Silva R, Vuong C, Zhang Z, Bautista DM, Woolf CJ. Dissecting the precise nature of itch-evoked scratching. Neuron 2021; 109:3075-3087.e2. [PMID: 34411514 PMCID: PMC8497439 DOI: 10.1016/j.neuron.2021.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 06/10/2021] [Accepted: 07/26/2021] [Indexed: 01/17/2023]
Abstract
Itch is a discrete and irritating sensation tightly coupled to a drive to scratch. Acute scratching developed evolutionarily as an adaptive defense against skin irritants, pathogens, or parasites. In contrast, the itch-scratch cycle in chronic itch is harmful, inducing escalating itch and skin damage. Clinically and preclinically, scratching incidence is currently evaluated as a unidimensional motor parameter and believed to reflect itch severity. We propose that scratching, when appreciated as a complex, multidimensional motor behavior, will yield greater insight into the nature of itch and the organization of neural circuits driving repetitive motor patterns. We outline the limitations of standard measurements of scratching in rodent models and present new approaches to observe and quantify itch-evoked scratching. We argue that accurate quantitative measurements of scratching are critical for dissecting the molecular, cellular, and circuit mechanisms underlying itch and for preclinical development of therapeutic interventions for acute and chronic itch disorders.
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Affiliation(s)
- Nivanthika K Wimalasena
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - George Milner
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Ricardo Silva
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Cliff Vuong
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Zihe Zhang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Diana M Bautista
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Hellen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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16
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IL-31 and IL-8 in Cutaneous T-Cell Lymphoma: Looking for Their Role in Itch. Adv Hematol 2021; 2021:5582581. [PMID: 34335777 PMCID: PMC8318769 DOI: 10.1155/2021/5582581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/21/2021] [Accepted: 07/13/2021] [Indexed: 01/26/2023] Open
Abstract
The itch associated with cutaneous T-cell lymphoma (CTCL), including Mycosis Fungoides (MF) and Sézary syndrome (SS), is often severe and poorly responsive to treatment with antihistamines. Recent studies have highlighted the possible role of interleukins in nonhistaminergic itch. We investigated the role of IL-31 and IL-8 in CTCL, concerning disease severity and associated itch. Serum samples of 27 patients with CTCL (17 MF and 10 SS) and 29 controls (blood donors) were analyzed for interleukin- (IL-) 31 and IL-8; correlations with disease and itch severity were evaluated. IL-31 serum levels were higher in CTCL patients than in controls and higher in SS than in MF. Also, serum IL-31 levels were higher in patients with advanced disease compared to those with early disease, and they correlated positively with lactate dehydrogenase and beta 2-microglobulin levels, as well as with the Sézary cell count. Itch affected 67% of CTCL patients (MF: 47%; SS: 100%). Serum IL-31 levels were higher in itching patients than in controls and in patients without itching. There was no association between serum IL-8 and disease severity, nor with itching. Serum IL-8 levels correlated positively with peripheral blood leukocyte and neutrophil counts in CTCL patients. Our study suggests a role for IL-31 in CTCL-associated itch, especially in advanced disease and SS, offering a rational target for new therapeutic approaches. Increased serum IL-8 observed in some patients may be related to concomitant infections, and its role in exacerbating itch by recruiting neutrophils and promoting the release of neutrophil proteases deserves further investigation.
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17
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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.
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Affiliation(s)
| | | | - 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
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18
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Park HJ, Ahn S, Lee H, Hahm DH, Kim K, Yeom M. Acupuncture ameliorates not only atopic dermatitis-like skin inflammation but also acute and chronic serotonergic itch possibly through blockade of 5-HT 2 and 5-HT 7 receptors in mice. Brain Behav Immun 2021; 93:399-408. [PMID: 33524554 DOI: 10.1016/j.bbi.2021.01.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 01/18/2021] [Accepted: 01/21/2021] [Indexed: 11/25/2022] Open
Abstract
Acupuncture has been known to be effective for atopic dermatitis, especially ameliorating itch; however, its mechanisms are still unclear. The aim of this study was to test the anti-itch effects of acupuncture and to investigate its possible mechanisms. Acupuncture was performed at Gok-Ji (LI11) acupoints just before the injection of pruritogens in the mouse cheek model of acute itch and of MC903-induced atopic dermatitis displaying serotonergic chronic itch. Acupuncture significantly reduced acute itch triggered by compound 48/80, chloroquine, or especially serotonin. It also markedly reduced scratching behaviors evoked by the serotonin 5-HT2 receptor agonist α-methylserotonin and selective 5-HT7 receptor agonist LP 44. In addition, acupuncture treatment at LI11 had the preventive and therapeutic effects on persistent itch as well as the robust skin inflammation with epidermal thickening in mice with MC903-induced atopic dermatitis. It also considerably reduced the increased expression of 5-HT2A, 5-HT2B and 5-HT7 receptors in atopic dermatitis-like skin lesions in mice treated with MC903. Taken together, these findings highlight that acupuncture significantly ameliorates not only skin inflammation, but also acute and chronic serotonergic itch, possibly through blockade of serotonin 5-HT2 and 5-HT7 receptors.
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Affiliation(s)
- Hi-Joon Park
- Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; Department of Anatomy & Information Sciences, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Sora Ahn
- Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hyangsook Lee
- Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; Department of Anatomy & Information Sciences, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Dae-Hyun Hahm
- Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; Department of Physiology, School of Medicine, Kyung Hee University, 02447 Seoul, Republic of Korea; BioNanocomposite Research Center, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Kyuseok Kim
- Department of Ophthalmology, Otorhinolaryngology and Dermatology of Korean Medicine, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Mijung Yeom
- Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea.
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19
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Andoh T, Suzuki K, Konno M, Tsuneyama K, Kuraishi Y. Pharmacological Characterization of a Novel Mouse Model of Cholestatic Pruritus. Biol Pharm Bull 2020; 43:1111-1117. [PMID: 32612073 DOI: 10.1248/bpb.b20-00097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Patients with cholestatic liver diseases, such as primary biliary cirrhosis, usually suffer from pruritus. However, the pathogenesis of cholestatic pruritus is unclear, and there is no current effective treatment for it. In order to find a treatment for the condition, an appropriate mouse model should be developed. Therefore, here, we established a surgically-induced mouse model of cholestatic pruritus. The bile duct was ligated in order to block bile secretion from the anterior, right, and left lobes, with the exception of the caudate lobe. Serum levels of total bile acid increased after bile duct ligation (BDL). The spontaneous hind paw scratching was also increased in BDL mice. Spontaneous scratching was reduced in BDL mice by naloxone (µ-opioid receptor antagonist), U-50,488H (κ-opioid receptor agonist), and clonidine (α2-adrenoceptor agonist). Azelastine (H1 receptor antagonist with membrane-stabilizing activity) slightly reduced scratching. However, terfenadine (H1 receptor antagonist), methysergide (serotonin (5-HT)2 receptor antagonist), ondansetron (5-HT3 receptor antagonist), proteinase-activated receptor 2-neutralizing antibody, fluvoxamine (selective serotonin reuptake inhibitor), milnacipran (serotonin-noradrenalin reuptake inhibitor), and cyproheptadine (H1 and 5-HT2 receptor antagonist) did not affect scratching. These results suggested that partial obstruction of bile secretion in mice induced anti-histamine-resistant itching and that central opioid system is involved in cholestatic itching.
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Affiliation(s)
- Tsugunobu Andoh
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama.,Department of Pathological Pharmacology, College of Pharmacy, Kinjo Gakuin University
| | - Kazunari Suzuki
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Mitsuhiro Konno
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| | - Koichi Tsuneyama
- Department of Pathology and Laboratory Medicine, Institute of Health Biosciences, Tokushima University Graduate School
| | - Yasushi Kuraishi
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
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20
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Alhadeff AL, Park O, Hernandez E, Betley JN. Inhibition of Itch by Hunger and AgRP Neuron Activity. Neuroscience 2020; 450:126-134. [PMID: 32540365 PMCID: PMC7688492 DOI: 10.1016/j.neuroscience.2020.06.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/12/2020] [Accepted: 06/02/2020] [Indexed: 12/28/2022]
Abstract
Unpleasant somatosensory stimuli such as pain and itch can interrupt normal behavior. But survival can depend on resuming normal behavior before these challenges are fully resolved. The neural mechanisms that prioritize behavior when individuals are challenged with unpleasant somatosensory sensations, however, are not fully understood. Recently, we identified a neural circuit activated by hunger that can inhibit pain, prioritizing food seeking over tending to an injury. Here, we examine the ability of hunger, and neurons activated by hunger, to inhibit behavioral responses to another unpleasant somatosensory sensation - itch. We demonstrate that food deprivation inhibits scratching induced by three different pruritogenic stimuli: histamine, serotonin, and chloroquine. The inhibition of scratching correlates with the level of food deprivation, suggesting a cross-competition of alarm systems in the brain whereby more energy need more efficiently inhibits competing drives. Finally, we show that activity in hunger-sensitive, hypothalamic agouti-related protein (AgRP)-expressing neurons is sufficient to inhibit itch. Taken together, we showed that hunger or AgRP neuron activity inhibits itch, demonstrating that organisms have neural systems to filter and process ascending spinal signals activated by unpleasant somatosensory stimuli to prioritize salient needs.
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Affiliation(s)
- Amber L Alhadeff
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, United States.
| | - Onyoo Park
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Elen Hernandez
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - J Nicholas Betley
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, United States.
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21
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Kahremany S, Hofmann L, Gruzman A, Cohen G. Advances in Understanding the Initial Steps of Pruritoceptive Itch: How the Itch Hits the Switch. Int J Mol Sci 2020; 21:ijms21144883. [PMID: 32664385 PMCID: PMC7402353 DOI: 10.3390/ijms21144883] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 02/07/2023] Open
Abstract
Pruritoceptive (dermal) itch was long considered an accompanying symptom of diseases, a side effect of drug applications, or a temporary sensation induced by invading pruritogens, as produced by the stinging nettle. Due to extensive research in recent years, it was possible to provide detailed insights into the mechanism of itch mediation and modulation. Hence, it became apparent that pruritus is a complex symptom or disease in itself, which requires particular attention to improve patients’ health. Here, we summarize recent findings in pruritoceptive itch, including how this sensation is triggered and modulated by diverse endogenous and exogenous pruritogens and their receptors. A differentiation between mediating pruritogen and modulating pruritogen seems to be of great advantage to understand and decipher the molecular mechanism of itch perception. Only a comprehensive view on itch sensation will provide a solid basis for targeting this long-neglected adverse sensation accompanying numerous diseases and many drug side effects. Finally, we identify critical aspects of itch perception that require future investigation.
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Affiliation(s)
- Shirin Kahremany
- Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; (L.H.); (A.G.)
- The Skin Research Institute, The Dead Sea and Arava Science Center, Masada 86910, Israel;
- Correspondence:
| | - Lukas Hofmann
- Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; (L.H.); (A.G.)
| | - Arie Gruzman
- Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; (L.H.); (A.G.)
| | - Guy Cohen
- The Skin Research Institute, The Dead Sea and Arava Science Center, Masada 86910, Israel;
- Ben-Gurion University of the Negev, Eilat Campus, Eilat 8855630, Israel
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22
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Abstract
Itch is a unique sensation that helps organisms scratch away external threats; scratching itself induces an immune response that can contribute to more itchiness. Itch is induced chemically in the peripheral nervous system via a wide array of receptors. Given the superficial localization of itch neuron terminals, cells that dwell close to the skin contribute significantly to itch. Certain mechanical stimuli mediated by recently discovered circuits also contribute to the itch sensation. Ultimately, in the spinal cord, and likely in the brain, circuits that mediate touch, pain, and itch engage in cross modulation. Much of itch perception is still a mystery, but we present in this review the known ligands and receptors associated with itch. We also describe experiments and findings from investigations into the spinal and supraspinal circuitry responsible for the sensation of itch.
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Affiliation(s)
- Mark Lay
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA;,
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA;,
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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23
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Domocos D, Selescu T, Ceafalan LC, Iodi Carstens M, Carstens E, Babes A. Role of 5-HT1A and 5-HT3 receptors in serotonergic activation of sensory neurons in relation to itch and pain behavior in the rat. J Neurosci Res 2020; 98:1999-2017. [PMID: 32537854 DOI: 10.1002/jnr.24633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/29/2020] [Accepted: 04/10/2020] [Indexed: 12/21/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) released by platelets, mast cells, and immunocytes is a potent inflammatory mediator which modulates pain and itch sensing in the peripheral nervous system. The serotonergic receptors expressed by primary afferent neurons involved in these sensory functions are not fully identified and appear to be to a large extent species dependent. Moreover, the mechanisms through which 5-HT receptor activation is coupled to changes in neuronal excitability have not been completely revealed. Using a combination of in vitro (calcium and voltage imaging and patch-clamp) and in vivo behavioral methods, we used both male and female Wistar rats to provide evidence for the involvement of two 5-HT receptor subtypes, 5-HT1A and 5-HT3, in mediating the sustained and transient effects, respectively, of 5-HT on rat primary afferent neurons involved in pain and itch processing. In addition, our results are consistent with a model in which sustained serotonergic responses triggered via the 5-HT1A receptor are due to closure of background potassium channels, followed by membrane depolarization and action potentials, during which the activation of voltage-gated calcium channels leads to calcium entry. Our results may provide a better understanding of mammalian serotonergic itch signaling.
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Affiliation(s)
- Dan Domocos
- Department of Anatomy, Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Tudor Selescu
- Department of Anatomy, Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Laura Cristina Ceafalan
- Cell Biology, Neuroscience and Experimental Myology Laboratory, 'Victor Babeș' National Institute of Pathology, Bucharest, Romania.,Department of Cellular & Molecular Biology and Histology, School of Medicine, 'Carol Davila' University of Medicine and Pharmacy, Bucharest, Romania
| | - Mirela Iodi Carstens
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California, Davis, CA, USA
| | - Earl Carstens
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California, Davis, CA, USA
| | - Alexandru Babes
- Department of Anatomy, Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
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Pecova T, Kocan I, Vysehradsky R, Pecova R. Itch and Cough - Similar Role of Sensory Nerves in Their Pathogenesis. Physiol Res 2020; 69:S43-S54. [PMID: 32228011 DOI: 10.33549/physiolres.934403] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Itch is the most common chief complaint in patients visiting dermatology clinics and is analogous to cough and also sneeze of the lower and upper respiratory tract, all three of which are host actions trying to clear noxious stimuli. The pathomechanisms of these symptoms are not completely determined. The itch can originate from a variety of etiologies. Itch originates following the activation of peripheral sensory nerve endings following damage or exposure to inflammatory mediators. More than one sensory nerve subtype is thought to subservepruriceptive itch which includes both unmyelinated C-fibers and thinly myelinated Adelta nerve fibers. There are a lot of mediators capable of stimulating these afferent nerves leading to itch. Cough and itch pathways are mediated by small-diameter sensory fibers. These cough and itch sensory fibers release neuropeptides upon activation, which leads to inflammation of the nerves. The inflammation is involved in the development of chronic conditions of itch and cough. The aim of this review is to point out the role of sensory nerves in the pathogenesis of cough and itching. The common aspects of itch and cough could lead to new thoughts and perspectives in both fields.
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Affiliation(s)
- T Pecova
- Clinic of Dermatovenerology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital in Martin, Martin, Slovak
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Complementary roles of murine Na V1.7, Na V1.8 and Na V1.9 in acute itch signalling. Sci Rep 2020; 10:2326. [PMID: 32047194 PMCID: PMC7012836 DOI: 10.1038/s41598-020-59092-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/17/2020] [Indexed: 12/19/2022] Open
Abstract
Acute pruritus occurs in various disorders. Despite severe repercussions on quality of life treatment options remain limited. Voltage-gated sodium channels (NaV) are indispensable for transformation and propagation of sensory signals implicating them as drug targets. Here, NaV1.7, 1.8 and 1.9 were compared for their contribution to itch by analysing NaV-specific knockout mice. Acute pruritus was induced by a comprehensive panel of pruritogens (C48/80, endothelin, 5-HT, chloroquine, histamine, lysophosphatidic acid, trypsin, SLIGRL, β-alanine, BAM8-22), and scratching was assessed using a magnet-based recording technology. We report an unexpected stimulus-dependent diversity in NaV channel-mediated itch signalling. NaV1.7−/− showed substantial scratch reduction mainly towards strong pruritogens. NaV1.8−/− impaired histamine and 5-HT-induced scratching while NaV1.9 was involved in itch signalling towards 5-HT, C48/80 and SLIGRL. Furthermore, similar microfluorimetric calcium responses of sensory neurons and expression of itch-related TRP channels suggest no change in sensory transduction but in action potential transformation and conduction. The cumulative sum of scratching over all pruritogens confirmed a leading role of NaV1.7 and indicated an overall contribution of NaV1.9. Beside the proposed general role of NaV1.7 and 1.9 in itch signalling, scrutiny of time courses suggested NaV1.8 to sustain prolonged itching. Therefore, NaV1.7 and 1.9 may represent targets in pruritus therapy.
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Antipruritic Effects of Kappa Opioid Receptor Agonists: Evidence from Rodents to Humans. Handb Exp Pharmacol 2020; 271:275-292. [PMID: 33296031 DOI: 10.1007/164_2020_420] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Centrally administered bombesin induces scratching and grooming in rats. These behaviors were blocked by early benzomorphan kappa opioid receptor (KOR) agonists as reported by Gmerek and Cowan in 1984. This was the first evidence that KORs may be involved in the sensation of itch-like behaviors. Subsequent development of additional animal models for acute and chronic itch has led to important discoveries since then. For example, it was found that (a) gastrin-releasing peptide (GRP), natriuretic polypeptide b and their cognate receptors are keys for the transmission of itch sensation at the spinal cord level, (b) dynorphins (Dyns), the endogenous KOR agonists, work as inhibitory neuromodulators of itch at the spinal cord level, (c) in a mouse model for acute itch, certain KOR antagonists elicit scratching, (d) in mouse models of acute or chronic itch, KOR agonists (e.g., U50,488, nalfurafine, CR 845, nalbuphine) suppress scratching induced by different pruritogens, and (e) nalfurafine, CR 845, and nalbuphine are in the clinic or in clinical trials for pruritus associated with chronic kidney disease and chronic liver disease, as well as pruritus in chronic skin diseases.
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Sakai H, Ishida T, Sato K, Mandokoro K, Yabe S, Sato F, Chiba Y, Kon R, Ikarashi N, Kamei J. Interference of Skin Scratching Attenuates Accumulation of Neutrophils in Murine Allergic Contact Dermatitis Model. Inflammation 2019; 42:2226-2235. [DOI: 10.1007/s10753-019-01086-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Dong X, Dong X. Peripheral and Central Mechanisms of Itch. Neuron 2019; 98:482-494. [PMID: 29723501 DOI: 10.1016/j.neuron.2018.03.023] [Citation(s) in RCA: 222] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/12/2018] [Accepted: 03/15/2018] [Indexed: 12/15/2022]
Abstract
Itch is a unique sensory experience that is encoded by genetically distinguishable neurons both in the peripheral nervous system (PNS) and central nervous system (CNS) to elicit a characteristic behavioral response (scratching). Itch interacts with the other sensory modalities at multiple locations, from its initiation in a particular dermatome to its transmission to the brain where it is finally perceived. In this review, we summarize the current understanding of the molecular and neural mechanisms of itch by starting in the periphery, where itch is initiated, and discussing the circuits involved in itch processing in the CNS.
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Affiliation(s)
- Xintong Dong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Fawaz B, Chamseddin BH, Griffin JR. Defining the role of mirtazapine in the treatment of refractory pruritus. J DERMATOL TREAT 2019; 32:132-136. [PMID: 31180795 DOI: 10.1080/09546634.2019.1630702] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND/OBJECTIVE Mirtazapine has traditionally been used for the treatment of major depressive disorder, with an added benefit in patients who have comorbid insomnia or anxiety. Recent studies describe its usefulness in treating refractory pruritus of various causes as well. Our goal is to better define the use of mirtazapine in the treatment of refractory pruritus. METHOD Through a thorough literature review of PubMed, we identified all reports of the use of mirtazapine for pruritus. RESULTS Upon examination of 8 supporting articles, we found mirtazapine has quality evidence for the treatment of intra-thecal morphine-induced pruritus. Mirtazapine may also be effective in treating pruritus related to various other conditions, including psoriasis, atopic dermatitis, cutaneous malignancies (primary or metastatic), hematologic malignancies (lymphomas and leukemias), liver failure, renal failure, cholestasis, as well as pruritus of unknown origin. CONCLUSIONS Mirtazapine plays a role in treatment for intra-thecel morphine-induced pruritis yet high-quality trials are needed to confirm its efficacy in other dermatologic conditions.
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Affiliation(s)
- Bilal Fawaz
- Department of Dermatology, Baylor University Medical Center, Dallas, TX, USA
| | | | - John R Griffin
- Department of Dermatology, Baylor University Medical Center, Dallas, TX, USA
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Meixiong J, Anderson M, Limjunyawong N, Sabbagh MF, Hu E, Mack MR, Oetjen LK, Wang F, Kim BS, Dong X. Activation of Mast-Cell-Expressed Mas-Related G-Protein-Coupled Receptors Drives Non-histaminergic Itch. Immunity 2019; 50:1163-1171.e5. [PMID: 31027996 DOI: 10.1016/j.immuni.2019.03.013] [Citation(s) in RCA: 206] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 10/24/2018] [Accepted: 03/14/2019] [Indexed: 11/28/2022]
Abstract
Classical itch studies have focused on immunoglobulin E (IgE)-mediated mast cell activation and histamine release. Recently, members of the Mas-related G-protein-coupled receptor (Mrgpr) family have been identified as mast cell receptors, but their role in itch is unclear. Here, we report that mast cell activation via Mrgprb2 evoked non-histaminergic itch in mice independently of the IgE-Fc epsilon RI (FcεRI)-histamine axis. Compared with IgE-FcεRI stimulation, Mrgprb2 activation of mast cells was distinct in both released substances (histamine, serotonin, and tryptase) and the pattern of activated itch-sensory neurons. Mrgprb2 deficiency decreased itch in multiple preclinical models of allergic contact dermatitis (ACD), a pruritic inflammatory skin disorder, and both mast cell number and PAMP1-20 concentrations (agonist of the human Mrgprb2 homolog, MRGPRX2) were increased in human ACD skin. These findings suggest that this pathway may represent a therapeutic target for treating ACD and mast-cell-associated itch disorders in which antihistamines are ineffective.
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Affiliation(s)
- James Meixiong
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael Anderson
- 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
| | - Mark F Sabbagh
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Eric Hu
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Madison R Mack
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Landon K Oetjen
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Fang Wang
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Brian S Kim
- Center for the Study of Itch, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, 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.
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Li S, Andoh T, Zhang Q, Uta D, Kuraishi Y. β2-Microglobulin, interleukin-31, and arachidonic acid metabolites (leukotriene B4 and thromboxane A2) are involved in chronic renal failure-associated itch-associated responses in mice. Eur J Pharmacol 2019; 847:19-25. [DOI: 10.1016/j.ejphar.2019.01.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 12/26/2018] [Accepted: 01/14/2019] [Indexed: 12/20/2022]
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Carrion AF, Rosen JD, Levy C. Understanding and Treating Pruritus in Primary Biliary Cholangitis. Clin Liver Dis 2018; 22:517-532. [PMID: 30259850 DOI: 10.1016/j.cld.2018.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pruritus is a common symptom with primary biliary cholangitis. Research has focused on refining understanding of the neurohumoral pathways involved in transduction of pruritus from peripheral cutaneous receptors to the central nervous system, and identifying modulating drugs. Current treatments have variable efficacy and safety. Because of the deleterious effects on quality of life or debilitation, many patients necessitate individualized therapeutic approaches; clinicians may need to consider invasive treatment options. This article highlights various therapeutic interventions, from general measures to invasive strategies, and novel agents under investigation, providing clinicians with the management tricks of the trade.
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Affiliation(s)
- Andres F Carrion
- Division of Gastroenterology and Hepatology, Texas Tech University Health Sciences Center, 4800 Alberta Avenue, El Paso, TX 79905, USA.
| | - Jordan D Rosen
- Department of Dermatology and Cutaneous Surgery, Miami Itch Center, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Cynthia Levy
- Division of Hepatology, Schiff Center for Liver Diseases, University of Miami Miller School of Medicine, Miami, FL, USA
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Jafferany M, Davari ME. Itch and psyche: psychiatric aspects of pruritus. Int J Dermatol 2018; 58:3-23. [PMID: 29917231 DOI: 10.1111/ijd.14081] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 04/07/2018] [Accepted: 05/16/2018] [Indexed: 01/02/2023]
Abstract
Itch, also referred to as pruritus, is an unpleasant cutaneous sensation provoking the desire to scratch. It is often an uncomfortable, subjective sensation responsible for decreased quality of life in a variety of psychodermatological conditions. Comorbid psychiatric conditions, including depression and anxiety, are frequently associated with itch and scratch cycle. The reciprocal and intricate relationship between the psyche and itch has been widely studied. The neurobiology of itch involves the complexity of specific mediators, itch-related neuronal pathways, and central processing of itch. The connection between itch and the psyche can be grouped under three headings: pruritic diseases with psychosocial sequelae, pruritic diseases aggravated by psychosocial factors, and psychiatric disorders causing pruritus. Itch and pain modulation go together in most circumstances and involve various substances including histamine, interleukins, protease-activated receptors, transient receptor potential receptors, opioids, and cannabinoids. The close interaction between keratinocytes and nerve endings modulating pain and itch also play a major role. Management of itch associated with its psychosomatic components is directed at an underlying cause and adopting a holistic approach to address not only dermatologic and somatosensory aspects, but also the cognitive, emotional, and psychosocial components. An integrated multidisciplinary team consisting of a dermatologist, psychiatrist, psychologist, and social worker is vital in addressing the multifaceted aspects of pruritus.
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Esancy K, Condon L, Feng J, Kimball C, Curtright A, Dhaka A. A zebrafish and mouse model for selective pruritus via direct activation of TRPA1. eLife 2018; 7:32036. [PMID: 29561265 PMCID: PMC5912907 DOI: 10.7554/elife.32036] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 03/19/2018] [Indexed: 11/13/2022] Open
Abstract
Little is known about the capacity of lower vertebrates to experience itch. A screen of itch-inducing compounds (pruritogens) in zebrafish larvae yielded a single pruritogen, the TLR7 agonist imiquimod, that elicited a somatosensory neuron response. Imiquimod induced itch-like behaviors in zebrafish distinct from those induced by the noxious TRPA1 agonist, allyl isothiocyanate. In the zebrafish, imiquimod-evoked somatosensory neuronal responses and behaviors were entirely dependent upon TRPA1, while in the mouse TRPA1 was required for the direct activation of somatosensory neurons and partially responsible for behaviors elicited by this pruritogen. Imiquimod was found to be a direct but weak TRPA1 agonist that activated a subset of TRPA1 expressing neurons. Imiquimod-responsive TRPA1 expressing neurons were significantly more sensitive to noxious stimuli than other TRPA1 expressing neurons. Together, these results suggest a model for selective itch via activation of a specialized subpopulation of somatosensory neurons with a heightened sensitivity to noxious stimuli. Itch is a common and uncomfortable sensation that creates a strong desire to scratch. This mechanism may have evolved so animals can remove harmful parasites or substances from themselves. Feelings like touch, pain, and itch arise when stimuli such as mechanical pressure, temperature, or chemicals activate groups of specialized neurons in the skin. This response takes place when certain proteins – or receptors – at the surface of the neurons are stimulated. For instance, TRP ion channels such as TRPA1 play an important role in both the itch and pain responses. In mammals, directly activating these channels elicits pain. Itch is felt when itch responsive receptors are activated on a distinct set of neurons, which in turn activate TRP receptors. Although these processes have been well-studied in mammals, little is known about the existence of itch sensation in other animals. To explore this, Esancy, Condon, Feng et al. exposed zebrafish to chemicals that induce itch in mammals, and found that imiquimod, a medicine used to treat certain skin conditions, can elicit itch in fish. When this chemical was injected into the lips of a fish, the animal rubbed them against the walls of its tank, akin to scratching an itch. Further experiments showed that imiquimod directly activated the pain-sensing ion channel TRPA1. In fact, this receptor was essential to the ‘scratching’ behavior: fish genetically engineered to lack TRPA1 did not react to the drug. Fluorescent proteins were then used to track when the neurons that carry TRPA1 were activated.This revealed that, in the skin of zebrafish, there are at least two functionally distinct populations neurons that express TRPA1. One population, whose activation is associated with the animal ‘scratching’, responds even when TRPA1 receives a low level of stimulation. The other population is less sensitive: it responds only to high-intensity stimuli and is associated with a pain response such as freezing and slower movements. Further experiments in the mouse suggest that this mechanism is present in mammals as well. This coding strategy explains how pain and itch can be experienced when the same receptors are being activated. Studying how animals like fish experience itch gives an insight into how detecting these sensations could have evolved. In turn, understanding this mechanism at the molecular and cellular levels may help find new ways to design better treatments for itch and pain disorders.
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Affiliation(s)
- Kali Esancy
- Department of Biological Structure, University of Washington, Seattle, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, United States
| | - Logan Condon
- Department of Biological Structure, University of Washington, Seattle, United States
| | - Jing Feng
- Center for the Study of Itch, Washington University, St. Louis, United States
| | - Corinna Kimball
- Department of Biological Structure, University of Washington, Seattle, United States
| | - Andrew Curtright
- Department of Biological Structure, University of Washington, Seattle, United States
| | - Ajay Dhaka
- Department of Biological Structure, University of Washington, Seattle, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, United States
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Steinhoff M, Buddenkotte J, Lerner EA. Role of mast cells and basophils in pruritus. Immunol Rev 2018; 282:248-264. [DOI: 10.1111/imr.12635] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Martin Steinhoff
- Department of Dermatology and Venereology; Hamad Medical Corporation; Doha Qatar
- Translational Research Institute; Hamad Medical Corporation; Doha Qatar
- Weill Cornell Medicine-Qatar; Doha Qatar
- Medical School; Qatar University; Doha Qatar
- Department Of Dermatology and UCD Charles Institute for Translational Dermatology; University College Dublin; Dublin Ireland
| | - Jörg Buddenkotte
- Department of Dermatology and Venereology; Hamad Medical Corporation; Doha Qatar
- Translational Research Institute; Hamad Medical Corporation; Doha Qatar
| | - Ethan A. Lerner
- Cutaneous Biology Research Center; Department of Dermatology; Massachusetts General Hospital/Harvard Medical School; Charlestown MA USA
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Attenuation of serotonin-induced itch by sumatriptan: possible involvement of endogenous opioids. Arch Dermatol Res 2018; 310:165-172. [DOI: 10.1007/s00403-018-1809-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 12/23/2017] [Accepted: 01/12/2018] [Indexed: 02/03/2023]
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Sakai K, Sanders KM, Youssef MR, Yanushefski KM, Jensen LE, Yosipovitch G, Akiyama T. Role of neurturin in spontaneous itch and increased nonpeptidergic intraepidermal fiber density in a mouse model of psoriasis. Pain 2017; 158:2196-2202. [PMID: 28825602 PMCID: PMC5676563 DOI: 10.1097/j.pain.0000000000001025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Psoriasis is often accompanied by itch, but the mechanisms behind this symptom remain elusive. Dynamic changes in epidermal innervation have been observed under chronic itch conditions. Therefore, we investigated whether epidermal innervation is altered in the imiquimod-induced psoriasis mouse model, whether blockade of neurotrophic growth factor signaling can reduce these changes, and whether this system can impact psoriatic itch. Over the 7-day time course of imiquimod treatment, the density of epidermal nonpeptidergic nerves significantly increased, whereas the density of peptidergic nerves significantly decreased. The nonpeptidergic epidermal nerves expressed glial cell line-derived neurotrophic factor (GDNF) family receptor GFRα-1 and GFRα-2, the ligand-binding domains for GDNF and neurturin (NRTN). The NRTN mRNA expression was elevated in the skin of imiquimod-treated mice, whereas the GDNF mRNA expression was decreased. Treatment of imiquimod-challenged mice with an NRTN-neutralizing antibody significantly reduced nonpeptidergic nerve density as well as spontaneous scratching. These results indicate that NRTN contributes to an increase in the epidermal density of nonpeptidergic nerves in the imiquimod-induced psoriasis model, and this increase may be a factor in chronic itch for these mice. Therefore, inhibition of NRTN could be a potential treatment for chronic itch in psoriasis.
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Affiliation(s)
- Kent Sakai
- Department of Dermatology and Cutaneous Surgery, Miami Itch Center, University of Miami, Miami, FL
| | - Kristen M. Sanders
- Department of Dermatology and Cutaneous Surgery, Miami Itch Center, University of Miami, Miami, FL
| | | | | | - Liselotte E. Jensen
- Department of Microbiology and Immunology, Temple University Lewis Katz School of Medicine, Philadelphia, PA
| | - Gil Yosipovitch
- Department of Dermatology and Cutaneous Surgery, Miami Itch Center, University of Miami, Miami, FL
| | - Tasuku Akiyama
- Department of Dermatology and Cutaneous Surgery, Miami Itch Center, University of Miami, Miami, FL
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Involvement of thromboxane A 2 in interleukin-31-induced itch-associated response in mice. Pharmacol Rep 2017; 70:251-257. [PMID: 29477033 DOI: 10.1016/j.pharep.2017.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Revised: 09/07/2017] [Accepted: 10/02/2017] [Indexed: 11/21/2022]
Abstract
BACKGROUND Atopic dermatitis is a chronic and severe pruritic skin disease. Interlukin-31 (IL-31) has been recently demonstrated to be one of the key pruritogens in atopic dermatitis. However, the mechanisms underlying IL-31-induced itching remains unclear. In our previous study, we have shown that thromboxane (TX) A2 is involved in itch-associated responses in mice with atopy-like skin diseases. METHODS IL-31 was given intradermally into the rostral back of ICR mice and the hind-paw scratching to the injection site were counted. Expression of TX synthase and IL-31 receptors were analyzed using immunohistochemical staining or RT-PCR in mouse skin or primary cultures of mouse keratinocytes. The concentration of TXB2, a metabolite of TXA2, in the skin and the culture medium of primary cultures of mouse keratinocytes was measured using enzyme immunoassay. The concentration of intracellular Ca2+ ions in mouse keratinocytes was measured using the calcium imaging method. RESULTS An intradermal injection of IL-31 elicited scratching, an itch-related response, in mice. The scratching was inhibited by TP TXA2 receptor antagonist DCHCH. The distribution of TX synthase and IL-31RA receptor was mainly epidermal keratinocytes in the skin. The primary cultures of keratinocytes expressed the mRNAs of TX synthase and IL-31 receptors. IL-31 increased the concentration of TXB2, which was inhibited by TX synthase inhibitor sodium ozagrel and EGTA, in the skin and the culture medium of primary cultures of keratinocytes. IL-31 increased the concentration of intracellular Ca2+ ions in mouse keratinocytes. CONCLUSION It is suggested that IL-31 elicits itch-associated responses through TXA2 produced from keratinocytes.
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Haddadi NS, Ostadhadi S, Shakiba S, Afshari K, Rahimi N, Foroutan A, Dehpour AR. Pharmacological evidence of involvement of nitric oxide pathway in anti-pruritic effects of sumatriptan in chloroquine-induced scratching in mice. Fundam Clin Pharmacol 2017; 32:69-76. [DOI: 10.1111/fcp.12317] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 06/30/2017] [Accepted: 08/11/2017] [Indexed: 12/01/2022]
Affiliation(s)
- Nazgol-Sadat Haddadi
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
| | - Sattar Ostadhadi
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
- Brain and Spinal Cord Injury Research Center; Neuroscience Institute; Tehran University of Medical Sciences; Chamran highway Bagherkhan St., Imam Khomeini Hospital Tehran Iran
| | - Saeed Shakiba
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
| | - Khashayar Afshari
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
| | - Nastaran Rahimi
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
| | - Arash Foroutan
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
| | - Ahmad-Reza Dehpour
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Poorsina St., Enghelab Ave.; Tehran Iran
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Afzal R, Shim WS. Glucosylsphingosine Activates Serotonin Receptor 2a and 2b: Implication of a Novel Itch Signaling Pathway. Biomol Ther (Seoul) 2017; 25:497-503. [PMID: 28208011 PMCID: PMC5590793 DOI: 10.4062/biomolther.2016.207] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/01/2016] [Accepted: 12/13/2016] [Indexed: 02/06/2023] Open
Abstract
Recent reports claimed that glucosylsphingosine (GS) is highly accumulated and specifically evoking itch-scratch responses in the skins of atopic dermatitis (AD) patients. However, it was unclear how GS can trigger itch-scratch responses, since there were no known molecular singling pathways revealed yet. In the present study, it was verified for the first time that GS can activate mouse serotonin receptor 2a (mHtr2a) and 2b (mHtr2b), but not 2c (mHtr2c) that are expressed in HEK293T cells. Specifically, effects of GS on all mouse serotonin receptor 2 subfamily were evaluated by calcium imaging techniques. The GS-induced intracellular calcium increase was dose-dependent, and antagonists such as ketanserin (Htr2a antagonist) and RS-127445 (Htr2b antagonist) significantly blocked the GS-induced responses. Moreover, the proposed GS-induced responses appear to be mediated by phospholipase C (PLC), since pretreatment of a PLC inhibitor U-73122 abolished the GS-induced responses. Additionally, the GS-induced calcium influx is probably mediated by endogenous TRPC ion channels in HEK293T cells, since pretreatment of SKF-96365, an inhibitor for TRPC, significantly suppressed GS-induced response. In conclusion, the present study revealed for the first time that GS can stimulate mHtr2a and mHtr2b to induce calcium influx, by utilizing PLC-dependent pathway afterwards. Considering that GS is regarded as a pruritogen in AD, the present study implicates a novel GS-induced itch signaling pathway.
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Affiliation(s)
- Ramsha Afzal
- College of Pharmacy, Gachon University, Incheon 21936, Republic of Korea
| | - Won-Sik Shim
- College of Pharmacy, Gachon University, Incheon 21936, Republic of Korea.,Gachon Institue of Pharmaceutical Sciences, Incheon 21936, Republic of Korea
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Andoh T, Maki T, Li S, Uta D. β2-Microglobulin elicits itch-related responses in mice through the direct activation of primary afferent neurons expressing transient receptor potential vanilloid 1. Eur J Pharmacol 2017; 810:134-140. [PMID: 28687195 DOI: 10.1016/j.ejphar.2017.07.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 07/03/2017] [Accepted: 07/03/2017] [Indexed: 12/23/2022]
Abstract
Uremic pruritus is an unpleasant symptom in patients undergoing hemodialysis, and the underlying mechanisms remain unclear. β2-Microglobulin (β2-MG) is well-known as an MHC class I molecule and its level is increased in the plasma of patients undergoing hemodialysis. In this study, we investigated whether β2-MG was a pruritogen in mice. Intradermal injections of β2-MG into the rostral back induced scratching in a dose-dependent manner. Intradermal injection of β2-MG into the cheek also elicited scratching, but not wiping. β2-MG-induced scratching was inhibited by the μ-opioid receptor antagonist naltrexone hydrochloride. β2-MG-induced scratching was not inhibited by antagonists of itch-related receptors (e.g., H1 histamine receptor (terfenadine), TP thromboxane receptor (DCHCH), BLT1 leukotriene B4 receptor (CMHVA), and proteinase-activated receptor 2 (FSLLRY-NH2)). However, β2-MG-induced scratching was attenuated in mice desensitized by repeated application of capsaicin and also by a selective transient receptor potential vanilloid 1 (TRPV1) antagonist (BCTC). In addition, β2-MG induced phosphorylation of extracellular signal-regulated kinase (a marker of activated neurons) in primary culture of dorsal root ganglion neurons that expressed TRPV1. These results suggest that β2-MG is a pruritogen and elicits itch-related responses, at least in part, through TRPV1-expressing primary sensory neurons.
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Affiliation(s)
- Tsugunobu Andoh
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
| | - Takahito Maki
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Sikai Li
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Daisuke Uta
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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Thébaut A, Debray D, Gonzales E. Physiopathologie et prise en charge thérapeutique du prurit cholestatique de l’enfant. Arch Pediatr 2017; 24:682-688. [DOI: 10.1016/j.arcped.2017.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/10/2017] [Accepted: 04/24/2017] [Indexed: 01/12/2023]
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Ostadhadi S, Haddadi NS, Foroutan A, Azimi E, Elmariah S, Dehpour AR. Development of resistance to serotonin-induced itch in bile duct ligated mice. Clin Exp Pharmacol Physiol 2017; 44:680-685. [DOI: 10.1111/1440-1681.12752] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 02/14/2017] [Accepted: 02/22/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Sattar Ostadhadi
- Brain and Spinal Cord Injury Research Center; Neurosciences Institute; Tehran University of Medical Sciences; Tehran Iran
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Tehran Iran
| | - Nazgol-Sadat Haddadi
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Tehran Iran
| | - Arash Foroutan
- Brain and Spinal Cord Injury Research Center; Neurosciences Institute; Tehran University of Medical Sciences; Tehran Iran
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Tehran Iran
| | - Ehsan Azimi
- Cutaneous Biology Research Center; Massachusetts General Hospital; Charlestown MA USA
| | - Sarina Elmariah
- Cutaneous Biology Research Center; Massachusetts General Hospital; Charlestown MA USA
| | - Ahmad-Reza Dehpour
- Brain and Spinal Cord Injury Research Center; Neurosciences Institute; Tehran University of Medical Sciences; Tehran Iran
- Experimental Medicine Research Center; Tehran University of Medical Sciences; Tehran Iran
- Department of Pharmacology; School of Medicine; Tehran University of Medical Sciences; Tehran Iran
- Faculty of Pharmacy; Tehran University of Medical Sciences; Tehran Iran
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44
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Lee JS, Han JS, Lee K, Bang J, Lee H. The peripheral and central mechanisms underlying itch. BMB Rep 2017; 49:474-87. [PMID: 27418284 PMCID: PMC5227140 DOI: 10.5483/bmbrep.2016.49.9.108] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Indexed: 12/20/2022] Open
Abstract
Itch is one of the most distressing sensations that substantially impair quality of life. It is a cardinal symptom of many skin diseases and is also caused by a variety of systemic disorders. Unfortunately, currently available itch medications are ineffective in many chronic itch conditions, and they often cause undesirable side effects. To develop novel therapeutic strategies, it is essential to identify primary afferent neurons that selectively respond to itch mediators as well as the central nervous system components that process the sensation of itch and initiate behavioral responses. This review summarizes recent progress in the study of itch, focusing on itch-selective receptors, signaling molecules, neuronal pathways from the primary sensory neurons to the brain, and potential decoding mechanisms based on which itch is distinguished from pain. [BMB Reports 2016; 49(9): 474-487]
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Affiliation(s)
- Jae Seung Lee
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
| | | | - Kyeongho Lee
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
| | - Juwon Bang
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
| | - Hyosang Lee
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
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Akiyama T, Nagamine M, Davoodi A, Ivanov M, Carstens MI, Carstens E. Innocuous warming enhances peripheral serotonergic itch signaling and evokes enhanced responses in serotonin-responsive dorsal horn neurons in the mouse. J Neurophysiol 2017; 117:251-259. [PMID: 27784810 PMCID: PMC5220113 DOI: 10.1152/jn.00703.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/19/2016] [Indexed: 11/22/2022] Open
Abstract
Itch is often triggered by warming the skin in patients with itchy dermatitis, but the underlying mechanism is largely unknown. We presently investigated if warming the skin enhances histamine- or serotonin (5-HT)-evoked itch behavior or responses of sensory dorsal root ganglion (DRG) cells, and if responses of superficial dorsal horn neurons to innocuous warming are enhanced by these pruritogens. In a temperature-controlled environmental chamber, mice exhibited greater scratching following intradermal injection of 5-HT, but not histamine, SLIGRL, or BAM8-22, when the skin surface temperature was above 36°C. Calcium imaging of DRG cells in a temperature-controlled bath revealed that responses to 5-HT, but not histamine, were significantly greater at a bath temperature of 35°C vs. lower temperatures. Single-unit recordings revealed a subpopulation of superficial dorsal horn neurons responsive to intradermal injection of 5-HT. Of these, 58% responded to innocuous skin warming (37°C) prior to intradermal injection of 5-HT, while 100% responded to warming following intradermal injection of 5-HT. Warming-evoked responses were superimposed on the 5-HT-evoked elevation in firing and were significantly larger compared with responses pre-5-HT, as long as 30 min after the intradermal injection of 5-HT. Five-HT-insensitive units, and units that either did or did not respond to intradermal histamine, did not exhibit any increase in the incidence of warmth sensitivity or in the mean response to warming following intradermal injection of the pruritogen. The results suggest that 5-HT-evoked responses of pruriceptors are enhanced during skin warming, leading to increased firing of 5-HT-sensitive dorsal horn neurons that signal nonhistaminergic itch. NEW & NOTEWORTHY Skin warming often exacerbates itch in patients with itchy dermatitis. We demonstrate that warming the skin enhanced serotonin-evoked, but not histamine-evoked, itch behavior and responses of sensory dorsal root ganglion cells. Moreover, serotonin, but not histamine, enhanced responses of superficial dorsal horn neurons to innocuous warming. The results suggest that skin warming selectively enhances the responses of serotonin-sensitive pruriceptors, leading to increased firing of serotonin-sensitive dorsal horn neurons that signal nonhistaminergic itch.
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Affiliation(s)
- T Akiyama
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California; and
- Departments of Dermatology, Anatomy, and Cell Biology, Temple Itch Center, Temple University, Philadelphia, Pennsylvania
| | - M Nagamine
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California; and
| | - A Davoodi
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California; and
| | - M Ivanov
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California; and
| | - M Iodi Carstens
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California; and
| | - E Carstens
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California; and
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Ostadhadi S, Foroutan A, Momeny M, Norouzi-Javidan A, Azimi E, Kordjazy N, Dehpour AR. Evidence for the involvement of nitric oxide in cholestasis-induced itch associated response in mice. Biomed Pharmacother 2016; 84:1367-1374. [DOI: 10.1016/j.biopha.2016.10.068] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 10/23/2016] [Accepted: 10/24/2016] [Indexed: 12/16/2022] Open
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Siemens W, Xander C, Meerpohl JJ, Buroh S, Antes G, Schwarzer G, Becker G. Pharmacological interventions for pruritus in adult palliative care patients. Cochrane Database Syst Rev 2016; 11:CD008320. [PMID: 27849111 PMCID: PMC6734122 DOI: 10.1002/14651858.cd008320.pub3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND This is an update of the original Cochrane review published in 2013 (Issue 6). Pruritus occurs in patients with disparate underlying diseases and is caused by different pathologic mechanisms. In palliative care patients, pruritus is not the most prevalent but is one of the most puzzling symptoms. It can cause considerable discomfort and affects patients' quality of life. OBJECTIVES To assess the effects of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients. SEARCH METHODS For this update, we searched CENTRAL (the Cochrane Library), and MEDLINE (OVID) up to 9 June 2016 and Embase (OVID) up to 7 June 2016. In addition, we searched trial registries and checked the reference lists of all relevant studies, key textbooks, reviews and websites, and we contacted investigators and specialists in pruritus and palliative care regarding unpublished data. SELECTION CRITERIA We included randomised controlled trials (RCTs) assessing the effects of different pharmacological treatments, compared with a placebo, no treatment, or an alternative treatment, for preventing or treating pruritus in palliative care patients. DATA COLLECTION AND ANALYSIS Two review authors independently assessed the identified titles and abstracts, performed data extraction and assessed the risk of bias and methodological quality. We summarised the results descriptively and quantitatively (meta-analyses) according to the different pharmacological interventions and the diseases associated with pruritus. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created 10 'Summary of findings' tables. MAIN RESULTS In total, we included 50 studies and 1916 participants in the review. We added 10 studies with 627 participants for this update. Altogether, we included 39 different treatments for pruritus in four different patient groups.The overall risk of bias profile was heterogeneous and ranged from high to low risk. However, 48 studies (96%) had a high risk of bias due to low sample size (i.e. fewer than 50 participants per treatment arm). Using GRADE criteria, we downgraded our judgement on the quality of evidence to moderate in seven and to low in three comparisons for our primary outcome (pruritus), mainly due to imprecision and risk of bias.In palliative care participants with pruritus of different nature, the treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, reduced pruritus by 0.78 points (numerical analogue scale from 0 to 10; 95% confidence interval (CI) -1.19 to -0.37; one RCT, N = 48, quality of evidence: moderate) compared to placebo.For participants suffering from uraemic pruritus (UP), gabapentin was more effective than placebo (visual analogue scale (VAS): 0 to 10), mean difference (MD) -5.91, 95% CI -6.87 to -4.96; two RCTs, N = 118, quality of evidence: moderate). The κ-opioid receptor agonist nalfurafine showed amelioration of UP (VAS 0 to 10, MD -0.95, 95% CI -1.32 to -0.58; three RCTs, N = 422, quality of evidence: moderate) and only few adverse events. Moreover, cromolyn sodium relieved UP participants from pruritus by 2.94 points on the VAS (0 to 10) (95% CI -4.04 to -1.83; two RCTs, N = 100, quality of evidence: moderate) compared to placebo.In participants with cholestatic pruritus (CP), data favoured rifampin (VAS: 0 to 100, MD -24.64, 95% CI -31.08 to -18.21; two RCTs, N = 42, quality of evidence: low) and flumecinol (RR > 1 favours treatment group; RR 1.89, 95% CI 1.05 to 3.39; two RCTs, N = 69, quality of evidence: low) and showed a low incidence of adverse events in comparison with placebo. The opioid antagonist naltrexone reduced pruritus for participants with CP (VAS: 0 to 10, MD -2.26, 95% CI -3.19 to -1.33; two RCTs, N = 52, quality of evidence: moderate) compared to placebo. However, effects in participants with UP were inconclusive (percentage difference -12.30%, 95% CI -25.82% to 1.22%, one RCT, N = 32). Furthermore, large doses of opioid antagonists (e.g. naltrexone) could be inappropriate in palliative care patients because of the risk of reducing analgesia.For participants with HIV-associated pruritus, it is uncertain whether drug treatment with hydroxyzine hydrochloride, pentoxifylline, triamcinolone or indomethacin reduces pruritus because the evidence was of very low quality (e.g. small sample size, lack of blinding). AUTHORS' CONCLUSIONS Different interventions tended to be effective for CP and UP. However, therapies for patients with malignancies are still lacking. Due to the small sample sizes in most meta-analyses and the heterogeneous methodological quality of the included trials, the results should be interpreted cautiously in terms of generalisability.
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Affiliation(s)
- Waldemar Siemens
- Faculty of Medicine, University of Freiburg, GermanyClinic for Palliative Care, Medical Center ‐ University of FreiburgRobert‐Koch‐Straße 3FreiburgGermany
| | - Carola Xander
- Faculty of Medicine, University of Freiburg, GermanyClinic for Palliative Care, Medical Center ‐ University of FreiburgRobert‐Koch‐Straße 3FreiburgGermany
| | - Joerg J Meerpohl
- Medical Center ‐ University of FreiburgCochrane GermanyBreisacher Straße 153FreiburgGermany79110
| | - Sabine Buroh
- University Medical CenterLibrary of the Center of SurgeryHugstetterstrasse 55FreiburgBaden‐WürttembergGermany79115
| | - Gerd Antes
- Medical Center ‐ University of FreiburgCochrane GermanyBreisacher Straße 153FreiburgGermany79110
| | - Guido Schwarzer
- Medical Center ‐ University of FreiburgCenter for Medical Biometry and Medical InformaticsStefan‐Meier‐Str. 26FreiburgGermanyD‐79104
| | - Gerhild Becker
- Faculty of Medicine, University of Freiburg, GermanyClinic for Palliative Care, Medical Center ‐ University of FreiburgRobert‐Koch‐Straße 3FreiburgGermany
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Sakai K, Sanders KM, Youssef MR, Yanushefski KM, Jensen L, Yosipovitch G, Akiyama T. Mouse model of imiquimod-induced psoriatic itch. Pain 2016; 157:2536-2543. [PMID: 27437787 PMCID: PMC5069152 DOI: 10.1097/j.pain.0000000000000674] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Itch is a major indicator of psoriasis, but the underlying mechanisms behind this symptom are largely unknown. To investigate the neuronal mechanisms of psoriatic itch, we tested whether mice subjected to the imiquimod-induced psoriasis model exhibit itch-associated behaviors. Mice received daily topical applications of imiquimod to the rostral back skin for 7 days. Imiquimod-treated mice exhibited a significant increase in spontaneous scratching behavior directed to the treated area as well as touch-evoked scratching (alloknesis). To characterize this model, we measured the mRNA expression levels of pruritogens and itch-relevant receptors/channels using real-time reverse transcription PCR. The mRNA expression of MrgprA3, MrgprC11, and MrgprD decreased gradually over time in the dorsal root ganglion (DRG) cells. There was no significant change in the mRNA expression of TRPV1 or TRPA1 in DRG cells. TRPV4 mRNA expression was transiently increased in the DRG cells, whereas TRPM8 mRNA was significantly decreased. The mRNA expression levels of histidine decarboxylase and tryptophan hydroxylase 1, as well as the intensity of histamine and serotonin immunoreactivity, were transiently increased in the skin on day 2, returning to baseline by day 7. Histamine H1-receptor antagonists, chlorpheniramine and olopatadine, significantly inhibited spontaneous scratching on day 2, but not day 7. Neither chlorpheniramine nor olopatadine affected alloknesis on day 2 or day 7. These results may reflect the limited antipruritic effects of histamine H1-receptor antagonists on human psoriasis. The imiquimod-induced psoriasis model seems to be useful for the investigation of itch and its sensitization in psoriasis.
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Affiliation(s)
- Kent Sakai
- Department of Dermatology, Temple Itch Center, Temple University, Philadelphia, PA, USA
| | - Kristen M Sanders
- Department of Dermatology, Temple Itch Center, Temple University, Philadelphia, PA, USA
| | - Marina R Youssef
- Department of Dermatology, Temple Itch Center, Temple University, Philadelphia, PA, USA
| | - Kevin M Yanushefski
- Department of Dermatology, Temple Itch Center, Temple University, Philadelphia, PA, USA
| | - Liselotte Jensen
- Department of Microbiology and Immunology, Temple Autoimmunity Center, Temple University, Philadelphia, PA, USA
| | - Gil Yosipovitch
- Department of Dermatology, Temple Itch Center, Temple University, Philadelphia, PA, USA
| | - Tasuku Akiyama
- Department of Dermatology, Temple Itch Center, Temple University, Philadelphia, PA, USA
- Department of Anatomy and Cell Biology, Temple University, Philadelphia, PA, USA
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49
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Hoeck EA, Marker JB, Gazerani P, H. Andersen H, Arendt-Nielsen L. Preclinical and human surrogate models of itch. Exp Dermatol 2016; 25:750-7. [DOI: 10.1111/exd.13078] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Emil A. Hoeck
- SMI; Department of Health Science and Technology; Faculty of Medicine; Aalborg University; Aalborg E Denmark
| | - Jens B. Marker
- SMI; Department of Health Science and Technology; Faculty of Medicine; Aalborg University; Aalborg E Denmark
| | - Parisa Gazerani
- SMI; Department of Health Science and Technology; Faculty of Medicine; Aalborg University; Aalborg E Denmark
| | - Hjalte H. Andersen
- SMI; Department of Health Science and Technology; Faculty of Medicine; Aalborg University; Aalborg E Denmark
| | - Lars Arendt-Nielsen
- SMI; Department of Health Science and Technology; Faculty of Medicine; Aalborg University; Aalborg E Denmark
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50
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Palmqvist N, Siller M, Klint C, Sjödin A. A human and animal model-based approach to investigating the anti-inflammatory profile and potential of the 5-HT2B receptor antagonist AM1030. JOURNAL OF INFLAMMATION-LONDON 2016; 13:20. [PMID: 27340371 PMCID: PMC4918035 DOI: 10.1186/s12950-016-0127-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 06/03/2016] [Indexed: 11/10/2022]
Abstract
Background Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by highly pruritic eczematous lesions that are commonly treated with topical corticosteroids and calcineurin inhibitors. Side-effects and safety concerns associated with these agents restrict their use, and new, safe treatment options are therefore needed. Recent reports suggest that serotonin, i.e. 5-hydroxytryptamine (5-HT) and the 5-HT2 receptor family may contribute to inflammation and pruritus in the skin. The objective of this particular study was to investigate the 5HT2B receptor antagonist AM1030 with respect to its anti-inflammatory profile and potential. Methods AM1030 was tested in a set of distinct human and rodent in vitro and in vivo models, differing with respect to e.g. T cell involvement, triggering stimulus, main read-outs and route of drug administration. The in vitro systems used were staphylococcal enterotoxin A (SEA)-stimulated human peripheral blood mononuclear cells, lipopolysaccharide (LPS)-stimulated human primary monocytes, LPS-stimulated human THP-1 monocytes and LPS-stimulated mouse primary macrophages. The in vivo systems used were LPS- and SEA-induced cytokine production in the mouse, antigen-induced arthritis in the rat, glucose-6-phosphate isomerase-induced arthritis in the mouse and delayed-type hypersensitivity reaction in the mouse. In addition, different cell populations were analyzed with respect to their expression of the 5-HT2B receptor at the mRNA level. Results AM1030 significantly reduced both T cell-dependent and T cell-independent inflammatory responses, in vivo and in vitro. Due to the low or absent expression of the 5-HT2B receptor on T cell populations, the influence of AM1030 in T cell-dependent systems is suggested to be mediated via an indirect effect involving antigen-presenting cell types, such as monocytes and macrophages. Conclusion Based on the wide range of model systems used in this study, differing e.g. with respect to species, T cell involvement, triggering stimuli, route of drug administration and read-outs, our results suggest a broad anti-inflammatory effect of AM1030 and identify the 5-HT2B receptor as a promising future target for anti-inflammatory intervention, e.g. in AD.
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Affiliation(s)
| | - Max Siller
- AnaMar AB, R&D, Scheelevägen 2, SE-223 81 Lund, Sweden
| | - Cecilia Klint
- AnaMar AB, R&D, Scheelevägen 2, SE-223 81 Lund, Sweden
| | - Anders Sjödin
- AnaMar AB, R&D, Scheelevägen 2, SE-223 81 Lund, Sweden
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