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Yoneshige A, Hagiyama M, Takashima Y, Ueno S, Inoue T, Kimura R, Koriyama Y, Ito A. Elevated Hydrostatic Pressure Causes Retinal Degeneration Through Upregulating Lipocalin-2. Front Cell Dev Biol 2021; 9:664327. [PMID: 34136483 PMCID: PMC8201777 DOI: 10.3389/fcell.2021.664327] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/10/2021] [Indexed: 12/13/2022] Open
Abstract
Elevation of intraocular pressure is a major risk factor for glaucoma development, which causes the loss of retinal ganglion cells (RGCs). Lipocalin 2 (Lcn2) is upregulated in glaucomatous retinae; however, whether Lcn2 is directly involved in glaucoma is debated. In this study, retinal explant cultures were subjected to increased water pressure using a two-chamber culture device, and Lcn2 protein levels were examined by immunoblotting. In situ TdT-mediated dUTP nick and labeling (TUNEL) and glial fibrillary acidic protein (GFAP) immunohistochemical assays were performed to assess apoptosis and gliosis, respectively. The neurotoxicity of Lcn2 in the retinal explant culture was determined with exogenous administration of recombinant Lcn2. The Lcn2 protein levels, percentage of TUNEL-positive cells, and GFAP-positive area were significantly higher in retinae cultured under 50 cm H2O pressure loads compared to those cultured under 20 cm H2O. We found that Lcn2 exhibited neurotoxicity in retinae at dose of 1 μg/ml. The negative effects of increased hydrostatic pressure were attenuated by the iron chelator deferoxamine. This is the first report demonstrating the direct upregulation of Lcn2 by elevating hydrostatic pressure. Modulating Lcn2 and iron levels may be a promising therapeutic approach for retinal degeneration.
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Affiliation(s)
- Azusa Yoneshige
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Man Hagiyama
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Yasutoshi Takashima
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Satoru Ueno
- Department of Ophthalmology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Takao Inoue
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Ryuichiro Kimura
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Yoshiki Koriyama
- Graduate School and Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan
| | - Akihiko Ito
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
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Zhang Y, Zhang H, Jiang B, Tong X, Yan S, Lu J. Current views on neuropeptides in atopic dermatitis. Exp Dermatol 2021; 30:1588-1597. [PMID: 33963624 DOI: 10.1111/exd.14382] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/24/2021] [Accepted: 04/26/2021] [Indexed: 12/19/2022]
Abstract
Atopic dermatitis (AD) is a chronic inflammatory skin disease involving skin barrier dysfunction and immune imbalance. However, the mechanism of AD is not clear completely and may be related to heredity and environment. Neuropeptides are a class of peptides secreted by nerve endings, they may play roles in promoting vasodilation, plasma extravasation, chemotaxis of inflammatory cells and mediating pruritus. Since itching and immune cell infiltration are the main manifestations of atopic dermatitis, to further investigate the impact of neuropeptides on AD, our review summarized the mechanisms of several common neuropeptides in AD and hypothesized that neuropeptides may be the novel potential targets in AD treatment.
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Affiliation(s)
- Yue Zhang
- Department of Dermatology, The Third Xiangya Hospital, Central South University, Changsha, China.,Xiangya School of Medicine, Central South University, Changsha, China
| | - Hanyi Zhang
- Department of Dermatology, The Third Xiangya Hospital, Central South University, Changsha, China.,Xiangya School of Medicine, Central South University, Changsha, China
| | - Boyue Jiang
- Department of Dermatology, The Third Xiangya Hospital, Central South University, Changsha, China.,Xiangya School of Medicine, Central South University, Changsha, China
| | - Xiaoliang Tong
- Department of Dermatology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Siyu Yan
- Department of Dermatology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Jianyun Lu
- Department of Dermatology, The Third Xiangya Hospital, Central South University, Changsha, China
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53
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Interleukin-31 and Pruritic Skin. J Clin Med 2021; 10:jcm10091906. [PMID: 33924978 PMCID: PMC8124688 DOI: 10.3390/jcm10091906] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 12/26/2022] Open
Abstract
Skin inflammation often evokes pruritus, which is the major subjective symptom in many inflammatory skin diseases such as atopic dermatitis and prurigo nodularis. Pruritus or itch is a specific sensation found only in the skin. Recent studies have stressed the pivotal role played by interleukin-31 (IL-31) in the sensation of pruritus. IL-31 is produced by various cells including T helper 2 cells, macrophages, dendritic cells and eosinophils. IL-31 signals via a heterodimeric receptor composed of IL-31 receptor A (IL-31RA) and oncostatin M receptor β. Recent clinical trials have shown that the anti-IL-31RA antibody nemolizumab can successfully decrease pruritus in patients with atopic dermatitis and prurigo nodularis. The IL-31 pathway and pruritic skin are highlighted in this review article.
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Nürnberger F, Leisengang S, Ott D, Murgott J, Gerstberger R, Rummel C, Roth J. Manifestation of lipopolysaccharide-induced tolerance in neuro-glial primary cultures of the rat afferent somatosensory system. Inflamm Res 2021; 70:429-444. [PMID: 33582876 PMCID: PMC8012319 DOI: 10.1007/s00011-021-01440-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/12/2021] [Accepted: 01/28/2021] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVE Bacterial lipopolysaccharide (LPS) may contribute to the manifestation of inflammatory pain within structures of the afferent somatosensory system. LPS can induce a state of refractoriness to its own effects termed LPS tolerance. We employed primary neuro-glial cultures from rat dorsal root ganglia (DRG) and the superficial dorsal horn (SDH) of the spinal cord, mainly including the substantia gelatinosa to establish and characterize a model of LPS tolerance within these structures. METHODS Tolerance was induced by pre-treatment of both cultures with 1 µg/ml LPS for 18 h, followed by a short-term stimulation with a higher LPS dose (10 µg/ml for 2 h). Cultures treated with solvent were used as controls. Cells from DRG or SDH were investigated by means of RT-PCR (expression of inflammatory genes) and immunocytochemistry (translocation of inflammatory transcription factors into nuclei of cells from both cultures). Supernatants from both cultures were assayed for tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) by highly sensitive bioassays. RESULTS At the mRNA-level, pre-treatment with 1 µg/ml LPS caused reduced expression of TNF-α and enhanced IL-10/TNF-α expression ratios in both cultures upon subsequent stimulation with 10 µg/ml LPS, i.e. LPS tolerance. SDH cultures further showed reduced release of TNF-α into the supernatants and attenuated TNF-α immunoreactivity in microglial cells. In the state of LPS tolerance macrophages from DRG and microglial cells from SDH showed reduced LPS-induced nuclear translocation of the inflammatory transcription factors NFκB and NF-IL6. Nuclear immunoreactivity of the IL-6-activated transcription factor STAT3 was further reduced in neurons from DRG and astrocytes from SDH in LPS tolerant cultures. CONCLUSION A state of LPS tolerance can be induced in primary cultures from the afferent somatosensory system, which is characterized by a down-regulation of pro-inflammatory mediators. Thus, this model can be applied to study the effects of LPS tolerance at the cellular level, for example possible modifications of neuronal reactivity patterns upon inflammatory stimulation.
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Affiliation(s)
- Franz Nürnberger
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Stephan Leisengang
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Daniela Ott
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Jolanta Murgott
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Rüdiger Gerstberger
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Christoph Rummel
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Joachim Roth
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany.
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Shiratori-Hayashi M, Yamaguchi C, Eguchi K, Shiraishi Y, Kohno K, Mikoshiba K, Inoue K, Nishida M, Tsuda M. Astrocytic STAT3 activation and chronic itch require IP 3R1/TRPC-dependent Ca 2+ signals in mice. J Allergy Clin Immunol 2021; 147:1341-1353. [PMID: 32781002 DOI: 10.1016/j.jaci.2020.06.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 05/26/2020] [Accepted: 06/16/2020] [Indexed: 12/26/2022]
Abstract
BACKGROUND Chronic itch is a debilitating symptom of inflammatory skin diseases, but the underlying mechanism is poorly understood. We have recently demonstrated that astrocytes in the spinal dorsal horn become reactive in models of atopic and contact dermatitis via activation of the transcription factor signal transducer and activator of transcription 3 (STAT3) and critically contribute to chronic itch. In general, STAT3 is transiently activated; however, STAT3 activation in reactive astrocytes of chronic itch model mice persistently occurs via an unknown mechanism. OBJECTIVE We aimed to determine the mechanisms of persistent activation of astrocytic STAT3 in chronic itch conditions. METHODS To determine the factors that are required for persistent activation of astrocytic STAT3, Western blotting and calcium imaging with cultured astrocytes or spinal cord slices were performed. Thereafter, chronic itch model mice were used for genetic and behavioral experiments to confirm the role of the factors determined to mediate persistent STAT3 activation from in vitro and ex vivo experiments in chronic itch. RESULTS IP3 receptor type 1 (IP3R1) knockdown in astrocytes suppressed IL-6-induced persistent STAT3 activation and expression of lipocalin-2 (LCN2), an astrocytic STAT3-dependent inflammatory factor that is required for chronic itch. IP3R1-dependent astrocytic Ca2+ responses involved Ca2+ influx through the cation channel transient receptor potential canonical (TRPC), which was required for persistent STAT3 activation evoked by IL-6. IL-6 expression was upregulated in dorsal root ganglion neurons in a mouse model of chronic itch. Dorsal root ganglion neuron-specific IL-6 knockdown, spinal astrocyte-specific IP3R1 knockdown, and pharmacologic spinal TRPC inhibition attenuated LCN2 expression and chronic itch. CONCLUSION Our findings suggest that IP3R1/TRPC channel-mediated Ca2+ signals elicited by IL-6 in astrocytes are necessary for persistent STAT3 activation, LCN2 expression, and chronic itch, and they may also provide new targets for therapeutic intervention.
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Affiliation(s)
- Miho Shiratori-Hayashi
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Chiharu Yamaguchi
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Kazushi Eguchi
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Yuto Shiraishi
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Keita Kohno
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Katsuhiko Mikoshiba
- RIKEN Center for Biosystems Dynamics Research, Hyogo, Japan; Faculty of Science, Toho University, Chiba, Japan; Shanghai Institute of Immunochemical Studies, Shanghai Tech University, Shanghai, China
| | - Kazuhide Inoue
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Motohiro Nishida
- Department of Translational Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan; Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences and Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Aichi, Japan
| | - Makoto Tsuda
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
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Takeuchi S, Inoue K, Kuretake K, Kiyomatsu-Oda M, Furue M. Dupilumab shows slow, steady effectiveness for intractable prurigo in patients with atopic dermatitis. J Dermatol 2021; 48:638-644. [PMID: 33742710 DOI: 10.1111/1346-8138.15843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/17/2021] [Accepted: 02/21/2021] [Indexed: 11/27/2022]
Abstract
Prurigo lesions in atopic dermatitis are intractable. This single-center, retrospective study examined dupilumab's clinical effects on intractable prurigo. Twenty adult atopic dermatitis patients (12 with prurigo, eight without) were administrated dupilumab. Its effects on itching and disease severity were examined with Numerical Rating Scale-Itch (NRS-I), Eczema Area and Severity Index (EASI), and Investigator Global Assessment (IGA) scores; body surface areas (BSA); and thymus- and activation-regulated chemokine (TARC), total immunoglobulin (Ig)E, and eosinophil levels. NRS-I scores, EASI scores, TARC levels, and total IgE levels before dupilumab treatment were not statistically different between the prurigo and non-prurigo groups. With dupilumab treatment, NRS-I scores, EASI scores, IGA scores, BSA, TARC levels, and total IgE levels were significantly reduced from baseline in both groups at 1-2 months and onward, but skin symptom improvement in the prurigo group was slower than in the non-prurigo group, as evidenced by significantly higher EASI scores, BSA, and TARC levels at several time points during the 12 months of dupilumab treatment. Prurigo patients were slower in EASI-50 achievement and significantly lower in EASI-90 achievement at 12 months than non-prurigo patients. Adherence to dupilumab was not different, but total equivalent amounts of concomitant therapeutic agents (corticosteroids and tacrolimus) used during dupilumab treatment were significantly higher in the prurigo group (median, 56.2 g/week) than in the non-prurigo group (median, 33.7 g/week). There were 2.2 adverse events per patient on average; ocular complaints were most frequent. Dupilumab was effective in treating intractable prurigo, but despite significantly greater concomitant therapeutic agent use, skin symptom improvement was slower in prurigo patients than in non-prurigo patients.
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Affiliation(s)
- Satoshi Takeuchi
- Department of Dermatology, Federation of National Public Service Personnel Mutual Aid Associations, Hamanomachi Hospital, Fukuoka, Japan.,Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Keiichi Inoue
- Department of Dermatology, Federation of National Public Service Personnel Mutual Aid Associations, Hamanomachi Hospital, Fukuoka, Japan
| | - Keisuke Kuretake
- Department of Dermatology, Federation of National Public Service Personnel Mutual Aid Associations, Hamanomachi Hospital, Fukuoka, Japan
| | - Mari Kiyomatsu-Oda
- Department of Dermatology, Federation of National Public Service Personnel Mutual Aid Associations, Hamanomachi Hospital, Fukuoka, Japan
| | - Masutaka Furue
- Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Hamada K, Ferguson LB, Mayfield RD, Krishnan HR, Maienschein-Cline M, Lasek AW. Binge-like ethanol drinking activates anaplastic lymphoma kinase signaling and increases the expression of STAT3 target genes in the mouse hippocampus and prefrontal cortex. GENES, BRAIN, AND BEHAVIOR 2021; 20:e12729. [PMID: 33641239 PMCID: PMC8944393 DOI: 10.1111/gbb.12729] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/04/2021] [Accepted: 02/26/2021] [Indexed: 02/03/2023]
Abstract
Alcohol use disorder (AUD) has a complex pathogenesis, making it a difficult disorder to treat. Identifying relevant signaling pathways in the brain may be useful for finding new pharmacological targets to treat AUD. The receptor tyrosine kinase anaplastic lymphoma kinase (ALK) activates the transcription factor STAT3 in response to ethanol in cell lines. Here, we show ALK activation and upregulation of known STAT3 target genes (Socs3, Gfap and Tnfrsf1a) in the prefrontal cortex (PFC) and ventral hippocampus (HPC) of mice after 4 days of binge-like ethanol drinking. Mice treated with the STAT3 inhibitor stattic drank less ethanol than vehicle-treated mice, demonstrating the behavioral importance of STAT3. To identify novel ethanol-induced target genes downstream of the ALK and STAT3 pathway, we analyzed the NIH LINCS L1000 database for gene signature overlap between ALK inhibitor (alectinib and NVP-TAE684) and STAT3 inhibitor (niclosamide) treatments on cell lines. These genes were then compared with differentially expressed genes in the PFC of mice after binge-like drinking. We found 95 unique gene candidates, out of which 57 had STAT3 binding motifs in their promoters. We further showed by qPCR that expression of the putative STAT3 genes Nr1h2, Smarcc1, Smarca4 and Gpnmb were increased in either the PFC or HPC after binge-like drinking. Together, these results indicate activation of the ALK-STAT3 signaling pathway in the brain after binge-like ethanol consumption, identify putative novel ethanol-responsive STAT3 target genes, and suggest that STAT3 inhibition may be a potential method to reduce binge drinking in humans.
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Affiliation(s)
- Kana Hamada
- Graduate Program in Neuroscience, University of Illinois at Chicago, Chicago, IL 60612 USA
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612 USA
| | - Laura B. Ferguson
- Waggoner Center for Alcohol Addiction Research and Department of Neuroscience, University of Texas at Austin, Austin, TX 78712 USA
- Department of Neurology, Dell Medical School, The University of Texas at Austin, Austin, TX 78712, USA
| | - R. Dayne Mayfield
- Waggoner Center for Alcohol Addiction Research and Department of Neuroscience, University of Texas at Austin, Austin, TX 78712 USA
| | - Harish R. Krishnan
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612 USA
| | | | - Amy W. Lasek
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612 USA
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Hwang SN, Lee JS, Seo K, Lee H. Astrocytic Regulation of Neural Circuits Underlying Behaviors. Cells 2021; 10:cells10020296. [PMID: 33535587 PMCID: PMC7912785 DOI: 10.3390/cells10020296] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/23/2021] [Accepted: 01/29/2021] [Indexed: 02/07/2023] Open
Abstract
Astrocytes, characterized by a satellite-like morphology, are the most abundant type of glia in the central nervous system. Their main functions have been thought to be limited to providing homeostatic support for neurons, but recent studies have revealed that astrocytes actually actively interact with local neural circuits and play a crucial role in information processing and generating physiological and behavioral responses. Here, we review the emerging roles of astrocytes in many brain regions, particularly by focusing on intracellular changes in astrocytes and their interactions with neurons at the molecular and neural circuit levels.
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Affiliation(s)
- Sun-Nyoung Hwang
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea;
| | - Jae Seung Lee
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea; (J.S.L.); (K.S.)
| | - Kain Seo
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea; (J.S.L.); (K.S.)
| | - Hyosang Lee
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea;
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea; (J.S.L.); (K.S.)
- Korea Brain Research Institute (KBRI), Daegu 41062, Korea
- Correspondence: ; Tel.: +82-53-785-6147
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Haruta-Tsukamoto A, Miyahara Y, Funahashi H, Nishimori T, Ishida Y. Perampanel attenuates scratching behavior induced by acute or chronic pruritus in mice. Biochem Biophys Res Commun 2020; 533:1102-1108. [PMID: 33028486 DOI: 10.1016/j.bbrc.2020.09.109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 09/24/2020] [Indexed: 11/28/2022]
Abstract
An itch is defined as an unpleasant sensation that evokes a desire to scratch. Glutamate is a major excitatory neurotransmitter in the mammalian central nervous system and has a crucial role in pruriceptive processing in the spinal dorsal horn. It is well known that glutamate exerts its effects by binding to various glutamate receptors including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and that AMPA/kainate receptors play a crucial role in pruriceptive processing; however, the precise role of AMPA receptors remains uncertain. Perampanel, an antiepileptic drug, is an antagonist of AMPA receptors. Pretreatment with perampanel dose-dependently attenuated the induction of scratching, a behavior typically associated with pruritus, by intradermal administration of the pruritogen chloroquine. In addition, the induction of scratching in mice painted with diphenylcyclopropenone and NC/Nga mice treated with Biostir AD, animal models of contact dermatitis and atopic dermatitis, respectively, was dose-dependently alleviated by administration of perampanel. These findings indicate that AMPA receptors play a crucial role in pruriceptive processing in mice with acute or chronic pruritus.
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Affiliation(s)
- Ayaka Haruta-Tsukamoto
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki, 889-1692, Japan
| | - Yu Miyahara
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki, 889-1692, Japan
| | - Hideki Funahashi
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki, 889-1692, Japan
| | - Toshikazu Nishimori
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki, 889-1692, Japan
| | - Yasushi Ishida
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki, 889-1692, Japan.
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Antimicrobial peptides: bridging innate and adaptive immunity in the pathogenesis of psoriasis. Chin Med J (Engl) 2020; 133:2966-2975. [PMID: 33237697 PMCID: PMC7752697 DOI: 10.1097/cm9.0000000000001240] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Antimicrobial peptides (AMPs) are small molecules produced by a myriad of cells and play important roles not only in protecting against infections and sustaining skin barrier homeostasis but also in contributing to immune dysregulation under pathological conditions. Recently, increasing evidence has indicated that AMPs, including cathelicidin (LL-37), human β-defensins, S100 proteins, lipocalin 2, and RNase 7, are highly expressed in psoriatic skin lesions. These peptides broadly regulate immunity by interacting with various immune cells and linking innate and adaptive immune responses during the progression of psoriasis. In this review, we summarize the recent findings regarding AMPs in the pathogenesis of psoriasis with a main focus on their immunomodulatory abilities.
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Furue M. Regulation of Skin Barrier Function via Competition between AHR Axis versus IL-13/IL-4‒JAK‒STAT6/STAT3 Axis: Pathogenic and Therapeutic Implications in Atopic Dermatitis. J Clin Med 2020; 9:E3741. [PMID: 33233866 PMCID: PMC7700181 DOI: 10.3390/jcm9113741] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/16/2020] [Accepted: 11/19/2020] [Indexed: 02/07/2023] Open
Abstract
Atopic dermatitis (AD) is characterized by skin inflammation, barrier dysfunction, and chronic pruritus. As the anti-interleukin-4 (IL-4) receptor α antibody dupilumab improves all three cardinal features of AD, the type 2 cytokines IL-4 and especially IL-13 have been indicated to have pathogenic significance in AD. Accumulating evidence has shown that the skin barrier function is regulated via competition between the aryl hydrocarbon receptor (AHR) axis (up-regulation of barrier) and the IL-13/IL-4‒JAK‒STAT6/STAT3 axis (down-regulation of barrier). This latter axis also induces oxidative stress, which exacerbates inflammation. Conventional and recently developed agents for treating AD such as steroid, calcineurin inhibitors, cyclosporine, dupilumab, and JAK inhibitors inhibit the IL-13/IL-4‒JAK‒STAT6/STAT3 axis, while older remedies such as coal tar and glyteer are antioxidative AHR agonists. In this article, I summarize the pathogenic and therapeutic implications of the IL-13/IL-4‒JAK‒STAT6/STAT3 axis and the AHR axis in AD.
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Affiliation(s)
- Masutaka Furue
- Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; ; Tel.: +81-92-642-5581; Fax: +81-92-642-5600
- Research and Clinical Center for Yusho and Dioxin, Kyushu University Hospital, Fukuoka 812-8582, Japan
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Molecular and Cellular Mechanisms of Itch in Psoriasis. Int J Mol Sci 2020; 21:ijms21218406. [PMID: 33182442 PMCID: PMC7664892 DOI: 10.3390/ijms21218406] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/05/2020] [Accepted: 11/06/2020] [Indexed: 02/06/2023] Open
Abstract
Itch (or pruritus) was not previously recognized as a serious symptom of psoriasis. However, approximately 60-90% of psoriatic patients with pruritus have stated that it deteriorates their quality of life. Since conventional antipruritic therapies, such as antihistamines, only exert limited effects, the establishment of a treatment option for itch in psoriasis is urgently needed. Although a definitive drug is not currently available, various itch mediators are known to be involved in pruritus in psoriasis. In this review, we describe the clinical features of pruritus in psoriasis, classify a wide range of itch mediators into categories, such as the nervous, immune, endocrine, and vascular systems, and discuss the mechanisms by which these mediators induce or aggravate itch in the pathophysiology of psoriasis.
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Spanos F, Liddelow SA. An Overview of Astrocyte Responses in Genetically Induced Alzheimer's Disease Mouse Models. Cells 2020; 9:E2415. [PMID: 33158189 PMCID: PMC7694249 DOI: 10.3390/cells9112415] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/26/2020] [Accepted: 11/02/2020] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia. Despite many years of intense research, there is currently still no effective treatment. Multiple cell types contribute to disease pathogenesis, with an increasing body of data pointing to the active participation of astrocytes. Astrocytes play a pivotal role in the physiology and metabolic functions of neurons and other cells in the central nervous system. Because of their interactions with other cell types, astrocyte functions must be understood in their biologic context, thus many studies have used mouse models, of which there are over 190 available for AD research. However, none appear able to fully recapitulate the many functional changes in astrocytes reported in human AD brains. Our review summarizes the observations of astrocyte biology noted in mouse models of familial and sporadic AD. The limitations of AD mouse models will be discussed and current attempts to overcome these disadvantages will be described. With increasing understanding of the non-neuronal contributions to disease, the development of new methods and models will provide further insights and address important questions regarding the roles of astrocytes and other non-neuronal cells in AD pathophysiology. The next decade will prove to be full of exciting opportunities to address this devastating disease.
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Affiliation(s)
- Fokion Spanos
- Neuroscience Institute, NYU Grossman School of Medicine, New York, NY 10016, USA;
| | - Shane A. Liddelow
- Neuroscience Institute, NYU Grossman School of Medicine, New York, NY 10016, USA;
- Department of Neuroscience and Physiology, NYU Grossman School of Medicine, New York, NY 10016, USA
- Department of Ophthalmology, NYU Grossman School of Medicine, New York, NY 10016, USA
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64
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Nakahara T, Kido‐Nakahara M, Tsuji G, Furue M. Basics and recent advances in the pathophysiology of atopic dermatitis. J Dermatol 2020; 48:130-139. [DOI: 10.1111/1346-8138.15664] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Takeshi Nakahara
- Department of DermatologyGraduate School of Medical SciencesKyushu University FukuokaJapan
- Division of Skin Surface Sensing Graduate School of Medical Sciences Kyushu University FukuokaJapan
| | - Makiko Kido‐Nakahara
- Department of DermatologyGraduate School of Medical SciencesKyushu University FukuokaJapan
| | - Gaku Tsuji
- Department of DermatologyGraduate School of Medical SciencesKyushu University FukuokaJapan
- Research and Clinical Center for Yusho and Dioxin Kyushu University Hospital Fukuoka Japan
| | - Masutaka Furue
- Department of DermatologyGraduate School of Medical SciencesKyushu University FukuokaJapan
- Division of Skin Surface Sensing Graduate School of Medical Sciences Kyushu University FukuokaJapan
- Research and Clinical Center for Yusho and Dioxin Kyushu University Hospital Fukuoka Japan
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65
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Koga K, Shiraishi Y, Yamagata R, Tozaki-Saitoh H, Shiratori-Hayashi M, Tsuda M. Intrinsic braking role of descending locus coeruleus noradrenergic neurons in acute and chronic itch in mice. Mol Brain 2020; 13:144. [PMID: 33109226 PMCID: PMC7590446 DOI: 10.1186/s13041-020-00688-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 10/19/2020] [Indexed: 11/24/2022] Open
Abstract
Itch is defined as an unpleasant sensation that provokes a desire to scratch. Our understanding of neuronal circuits for itch information transmission and processing in the spinal dorsal horn (SDH) has progressively advanced following the identification of SDH neuron subsets that are crucial for scratching behavior in models of itch. However, little is known about the control of acute and chronic itch by descending signals from the brain to the SDH. In this study, using genetic approaches that enable cell-type and circuit-specific functional manipulation, we reveal an intrinsic potential of locus coeruleus (LC)-noradrenergic (NAergic) neurons that project to the SDH to control acute and chronic itch. Activation and silencing of SDH-projecting LC-NAergic neurons reduced and enhanced scratching behavior, respectively, in models of histamine-dependent and -independent acute itch. Furthermore, in a model of chronic itch associated with contact dermatitis, repetitive scratching behavior was suppressed by the activation of the descending LC-NAergic pathway and by knocking out NA transporters specific to descending LC-NAergic neurons using a CRISPR-Cas9 system. Moreover, patch-clamp recording using spinal slices showed that noradrenaline facilitated inhibitory synaptic inputs onto gastrin-releasing peptide receptor-expressing SDH neurons, a neuronal subset known to be essential for itch transmission. Our findings suggest that descending LC-NAergic signaling intrinsically controls acute and chronic itch and provide potential therapeutic strategies for the treatment of acute and chronic itch.
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Affiliation(s)
- Keisuke Koga
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.,Department of Neurophysiology, Hyogo College of Medicine, Nishinomiya, Hyogo, 663-8501, Japan
| | - Yuto Shiraishi
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.,Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Ryo Yamagata
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Hidetoshi Tozaki-Saitoh
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.,Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Miho Shiratori-Hayashi
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.,Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Makoto Tsuda
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan. .,Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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66
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Saponin from Periploca forrestii Schltr Mitigates Oxazolone-Induced Atopic Dermatitis via Modulating Macrophage Activation. Mediators Inflamm 2020; 2020:4346367. [PMID: 33122966 PMCID: PMC7584956 DOI: 10.1155/2020/4346367] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 09/10/2020] [Accepted: 09/24/2020] [Indexed: 01/12/2023] Open
Abstract
Atopic dermatitis (AD) is a relapsing, acute, and chronic skin disease featured by intractable itching, eczematous skin. Conventional therapies based on immunosuppression such as corticosteroids are associated with multiple adverse reactions. Periploca forrestii Schltr saponin (PFS) was shown to potently inhibit murine arthritis by protecting bone and cartilage injury and suppressing NF-κB activation. However, its therapeutic effect on oxazolone-induced atopic dermatitis (AD) and the underlying mechanisms on macrophage are still unclear. The AD-like dermatitis was induced by repeated oxazolone challenge to the skin of BALB/c mice in vivo. Blood and ears were biochemically or histologically processed. RT-PCR, western blotting, and ELISA were conducted to evaluate the expression of macrophage factors. Mouse bone marrow-derived macrophages (BMDMs) stimulated with lipopolysaccharide (LPS) were used as a model in vitro. PFS treatment inhibited AD-like dermatitis development. PFS downregulated epidermis thickness and cell infiltration, with histological analysis of the skin lesion. PFS alleviated plasma immunoglobulin (Ig) E, IgG2a, and IgG1 levels. PFS downregulated the expression of M1 macrophage factors, tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, monocyte chemotactic protein-1 (MCP-1), and nitric oxide synthase2 (NOS2), and M2 macrophage factors, IL-4, arginase1 (Arg1) and CD163 in AD-like skin, which were confirmed by western blot and ELISA analysis. In addition, PFS inhibited LPS-induced macrophage polarization via the inhibition of the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and nuclear translocation of NF-κB p65. These results suggest that PFS exerted an antidermatitis effect against oxazolone by modulating macrophage activation. PFS administration might be useful in the treatment of AD and inflammatory skin diseases.
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67
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Meixiong J, Dong X, Weng HJ. Neuropathic Itch. Cells 2020; 9:cells9102263. [PMID: 33050211 PMCID: PMC7601786 DOI: 10.3390/cells9102263] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/12/2022] Open
Abstract
Neurologic insults as varied as inflammation, stroke, and fibromyalgia elicit neuropathic pain and itch. Noxious sensation results when aberrantly increased afferent signaling reaches percept-forming cortical neurons and can occur due to increased sensory signaling, decreased inhibitory signaling, or a combination of both processes. To treat these symptoms, detailed knowledge of sensory transmission, from innervated end organ to cortex, is required. Molecular, genetic, and behavioral dissection of itch in animals and patients has improved understanding of the receptors, cells, and circuits involved. In this review, we will discuss neuropathic itch with a focus on the itch-specific circuit.
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Affiliation(s)
- James Meixiong
- Solomon H. Snyder Department of Neuroscience and Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
| | - Xinzhong Dong
- Solomon H. Snyder Department of Neuroscience, Department of Dermatology, and Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hao-Jui Weng
- Department of Dermatology, Taipei Medical University-Shuang Ho Hospital, New Taipei City 23561, Taiwan
- Department of Dermatology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
- Correspondence:
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68
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Wu Z, Xue H, Zhang Y, Zhao P. Dexmedetomidine alleviates neurobehavioral impairments and myelination deficits following lipopolysaccharide exposure in early postnatal rats. Life Sci 2020; 263:118556. [PMID: 33038375 DOI: 10.1016/j.lfs.2020.118556] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 09/13/2020] [Accepted: 09/28/2020] [Indexed: 01/22/2023]
Abstract
AIMS White matter injury (WMI) is the main form of brain injury in preterm neonate survivors, and perinatal inflammation is implicated in the pathogenesis of WMI. It has been demonstrated that dexmedetomidine, an anesthetic adjuvant, possesses neuroprotective effects in both preclinical and clinical trials. The present study was conducted to explore whether dexmedetomidine could protect against neurobehavioral impairments and myelination deficits caused by lipopolysaccharide (LPS) exposure in the early postnatal rat brain. MAIN METHODS LPS (2 mg/kg) was intraperitoneally (i.p.) injected in Sprague-Dawley rat pups on postnatal day 2 (P2). Dexmedetomidine (25 μg/kg) or vehicle was given i.p. immediately after LPS injection. STAT3 and p-STAT3 expression were detected by western blot in rat brain 24 h after drug administration. Immunostaining for GFAP to was performed to evaluate astrocytic response at 24 h post-LPS and P14. Neurobehavioral tests (the righting reflex, negative geotaxis, and wire hanging maneuver tests) were performed from P5 to P10. Histological analysis of myelin content was accessed by immunohistochemistry for CNPase and MBP at P14. KEY FINDINGS Our results showed that treatment with dexmedetomidine significantly ameliorated LPS-induced neurobehavioral abnormalities and myelin damage, which is accompanied by suppression of STAT3 activation and reactive astrogliosis. SIGNIFICANCE Dexmedetomidine can alleviate neurobehavioral impairments and myelination deficits after LPS exposure in early postnatal rats, probably by mitigating STAT3-mediated reactive astrogliosis. Our results suggest that dexmedetomidine might be a promising agent to treat brain injury in neonates.
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Affiliation(s)
- Ziyi Wu
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Hang Xue
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Yahan Zhang
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Ping Zhao
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, China.
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69
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Spinal astrocytes in superficial laminae gate brainstem descending control of mechanosensory hypersensitivity. Nat Neurosci 2020; 23:1376-1387. [DOI: 10.1038/s41593-020-00713-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 08/24/2020] [Indexed: 12/16/2022]
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70
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Jaworek AK, Szepietowski JC, Szafraniec K, Jaworek M, Hałubiec P, Wojas-Pelc A, Pokorski M. Adipokines as Biomarkers of Atopic Dermatitis in Adults. J Clin Med 2020; 9:jcm9092858. [PMID: 32899610 PMCID: PMC7565141 DOI: 10.3390/jcm9092858] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/28/2020] [Accepted: 09/02/2020] [Indexed: 02/07/2023] Open
Abstract
Atopic dermatitis (AD) is characterized by chronic, relapsing, pruritic skin inflammation and does not have a well-understood pathogenesis. In this study, we addressed the contribution of adipokines to AD eczema based on the assessment of blood levels of adiponectin, resistin, leptin, lipocalin-2, and vaspin in adult non-obese patients suffering from chronic extrinsic childhood-onset AD. We investigated 49 AD patients with a median age of 37 years. The control group consisted of 30 age-matched healthy subjects. Adipokines were assessed in the serum by ELISA assays and the severity of AD with the SCORing Atopic Dermatitis (SCORAD) index. We found that adiponectin and resistin decreased and leptin appreciably increased in AD patients when compared to those in healthy subjects. Further, the levels of adiponectin and resistin were inversely related to the intensity of eczema. In conclusion, apart from the formerly investigated role of leptin in AD, this study points to adiponectin and resistin as the potential candidate adipokine biomarkers involved in shaping eczema intensity and severity, which may help predict disease exacerbations and enable the development of effective targeted therapeutic interventions.
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Affiliation(s)
- Andrzej Kazimierz Jaworek
- Department of Dermatology, Jagiellonian University Medical College, 31-008 Cracow, Poland;
- Correspondence:
| | - Jacek C. Szepietowski
- Department of Dermatology, Venereology and Allergology, Wroclaw Medical University, 50-367 Wroclaw, Poland;
| | - Krystyna Szafraniec
- Department of Epidemiology and Population Studies, Institute of Public Health, Faculty of Health Sciences, Jagiellonian University Medical College, 31-008 Cracow, Poland;
| | - Magdalena Jaworek
- Department of Physiotherapy, Faculty of Health Sciences, Jagiellonian University Medical College, 31-008 Cracow, Poland;
| | - Przemysław Hałubiec
- Student Scientific Group, Department of Dermatology, Jagiellonian University Medical College, 31-008 Cracow, Poland;
| | - Anna Wojas-Pelc
- Department of Dermatology, Jagiellonian University Medical College, 31-008 Cracow, Poland;
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71
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Role of reactive astrocytes in the spinal dorsal horn under chronic itch conditions. J Pharmacol Sci 2020; 144:147-150. [PMID: 32800684 DOI: 10.1016/j.jphs.2020.07.010] [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] [Received: 03/26/2020] [Revised: 07/02/2020] [Accepted: 07/27/2020] [Indexed: 12/25/2022] Open
Abstract
Astrocytes are the most abundant glial cells in the central nervous system (CNS), including the spinal cord. Neuronal damage induces astrocytes to become reactive and contribute to various CNS pathologies. Recent studies have demonstrated that astrocytes in the spinal dorsal horn (SDH) become reactive in a transcription factor signal transducer and activator of transcription 3-dependent manner without neuronal damage under chronic itch conditions, causing release of the factor lipocalin-2, leading to induction of sensitization of gastrin releasing peptide-induced chemical itch signaling in the SDH. In this review, we describe recent advances in our understanding of SDH neuronal pathways for itch transmission, the mechanisms of SDH astrocytic activation and its contribution to abnormal itch processing and discuss the role of reactive astrocytes in the SDH in abnormal sensory processing under chronic itch conditions.
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72
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Cevikbas F, Lerner EA. Physiology and Pathophysiology of Itch. Physiol Rev 2020; 100:945-982. [PMID: 31869278 PMCID: PMC7474262 DOI: 10.1152/physrev.00017.2019] [Citation(s) in RCA: 126] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 10/31/2019] [Accepted: 12/04/2019] [Indexed: 02/06/2023] Open
Abstract
Itch is a topic to which everyone can relate. The physiological roles of itch are increasingly understood and appreciated. The pathophysiological consequences of itch impact quality of life as much as pain. These dynamics have led to increasingly deep dives into the mechanisms that underlie and contribute to the sensation of itch. When the prior review on the physiology of itching was published in this journal in 1941, itch was a black box of interest to a small number of neuroscientists and dermatologists. Itch is now appreciated as a complex and colorful Rubik's cube. Acute and chronic itch are being carefully scratched apart and reassembled by puzzle solvers across the biomedical spectrum. New mediators are being identified. Mechanisms blur boundaries of the circuitry that blend neuroscience and immunology. Measures involve psychophysics and behavioral psychology. The efforts associated with these approaches are positively impacting the care of itchy patients. There is now the potential to markedly alleviate chronic itch, a condition that does not end life, but often ruins it. We review the itch field and provide a current understanding of the pathophysiology of itch. Itch is a disease, not only a symptom of disease.
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Affiliation(s)
- Ferda Cevikbas
- Dermira, Inc., Menlo Park, California; and Harvard Medical School and the Cutaneous Biology Research Center at Massachusetts General Hospital, Charlestown, Massachusetts
| | - Ethan A Lerner
- Dermira, Inc., Menlo Park, California; and Harvard Medical School and the Cutaneous Biology Research Center at Massachusetts General Hospital, Charlestown, Massachusetts
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73
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Miyahara Y, Funahashi H, Naono-Nakayama R, Haruta-Tsukamoto A, Muroi C, Kogoh Y, Nishimori T, Ishida Y. Serotonin and noradrenaline modulate chronic itch processing in mice. Eur J Pharmacol 2020; 883:173319. [PMID: 32619678 DOI: 10.1016/j.ejphar.2020.173319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 06/24/2020] [Accepted: 06/24/2020] [Indexed: 11/24/2022]
Abstract
The roles of serotonin and noradrenaline in the modulation of chronic pruriceptive processing currently remain unclear. To clarify the contribution of serotonin and noradrenaline to chronic itch, the effects of the administration of antidepressants or noradrenaline reuptake inhibitors were evaluated in the present study. A pretreatment with milnacipran, a serotonin and noradrenaline reuptake inhibitor, and mirtazapine, a noradrenergic and specific serotonergic antidepressant, attenuated the induction of spontaneous scratching behavior in mice with chronic itch. The administration of a serotonin reuptake inhibitor, such as fluvoxamine and paroxetine, but not escitalopram, or a noradrenaline reuptake inhibitor, such as atomoxetine and nisoxetine, ameliorated the induction of spontaneous scratching behavior in mice with chronic itch. Furthermore, this attenuation was reversed by the administration of yohimbine, a selective α2-adrenoceptor antagonist, or methysergide, a non-selective serotonin receptor antagonist. These results suggest that elevated serotonin and noradrenaline levels are involved in the attenuation of scratching behavior induced by chronic itch, and serotonin receptors and an α2-adrenoceptor play a crucial role in chronic pruriceptive processing.
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Affiliation(s)
- Yu Miyahara
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki, 889-1692, Japan
| | - Hideki Funahashi
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki, 889-1692, Japan
| | - Rumi Naono-Nakayama
- Division of Histology and Anatomy, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1 Fukumuro, Miyagino-ku, Sendai, Miyagi, 983-8536, Japan
| | - Ayaka Haruta-Tsukamoto
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki, 889-1692, Japan
| | - Chiyo Muroi
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki, 889-1692, Japan
| | - Yoichiro Kogoh
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki, 889-1692, Japan
| | - Toshikazu Nishimori
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki, 889-1692, Japan
| | - Yasushi Ishida
- Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki city, Miyazaki, 889-1692, Japan.
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Chen Y, Li H, Ding T, Li J, Zhang Y, Wang J, Yang X, Chong T, Long Y, Li X, Gao F, Lyu X. Lnc-M2 controls M2 macrophage differentiation via the PKA/CREB pathway. Mol Immunol 2020; 124:142-152. [PMID: 32563859 DOI: 10.1016/j.molimm.2020.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/31/2020] [Accepted: 06/03/2020] [Indexed: 12/18/2022]
Abstract
Long noncoding RNAs (lncRNAs) play an indispensable role in the process of M1 macrophage via regulating the development of macrophages and their responses to bacterial pathogens and viral infections. However, there are few studies on the lncRNA-mediated functions and regulatory mechanisms of M2 macrophage polarization. In this study, we found a number of differentially expressed lncRNAs between human monocyte derived M0 and M2 macrophages according to array analysis and quantitative polymerase chain reaction (qPCR) validation. The lncRNA RP11-389C8.2 (we named lnc-M2 in this study) was observed to be highly expressed in M2 macrophages. In Situ Localization and Quantification Analysis showed that lnc-M2 was expressed in the nucleus and cytosolic compartments of M2 macrophages. Notably, lnc-M2 knockdown enhanced the phagocytic ability of M2 macrophages. Ulteriorly, the results of RNA-Protein interaction experiments indicated that protein kinase A (PKA) was a lnc-M2 associated RNA-binding protein (RBP). Western blot showed that phosphorylated cAMP response element binding protein (p-CREB), a well-known key downstream transcription factor of PKA, was lowly phosphorylated in lnc-M2-silencing M2 macrophages. Furthermore, we found that transcriptional factor Signal Transducer And Activator Of Transcription 3 (STAT3) promoted lnc-M2 transcription along with the up-regulation of epigenetic histone modification markers at the lnc-M2 promoter locus, indicating that STAT3 activated lnc-M2 and eventually facilitated the process of M2 macrophage differentiation via the PKA/CREB pathway. Collectively, our date provide evidence that the transcription factor STAT3 can promote the transcription of lnc-M2 and facilitated the process of M2 macrophage differentiation via the PKA/CREB pathway. This study highlights a novel mechanism underlying the M2 macrophage differentiation.
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Affiliation(s)
- Yuxiang Chen
- Shenzhen Key Laboratory of Viral Oncology, Center for Clinical Research and Innovation (CCRI), Shenzhen Hospital, Southern Medical University, Shenzhen, China; Department of Dermatology, Nanfang Hospital of Southern Medical University, Guangzhou, China
| | - Hanzhao Li
- Shenzhen Key Laboratory of Viral Oncology, Center for Clinical Research and Innovation (CCRI), Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Tengteng Ding
- Shenzhen Key Laboratory of Viral Oncology, Center for Clinical Research and Innovation (CCRI), Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Jinbang Li
- Department of Pathology, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, Qingyuan, China
| | - Yuanbin Zhang
- Shenzhen Key Laboratory of Viral Oncology, Center for Clinical Research and Innovation (CCRI), Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Jianguo Wang
- Shenzhen Key Laboratory of Viral Oncology, Center for Clinical Research and Innovation (CCRI), Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Xu Yang
- Shenzhen Key Laboratory of Viral Oncology, Center for Clinical Research and Innovation (CCRI), Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Tuotuo Chong
- Shenzhen Key Laboratory of Viral Oncology, Center for Clinical Research and Innovation (CCRI), Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Yufei Long
- Shenzhen Key Laboratory of Viral Oncology, Center for Clinical Research and Innovation (CCRI), Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Xin Li
- Shenzhen Key Laboratory of Viral Oncology, Center for Clinical Research and Innovation (CCRI), Shenzhen Hospital, Southern Medical University, Shenzhen, China.
| | - Fei Gao
- Department of Physiology and Biomedical Engineering and Gastroenterology Research Unit, Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
| | - Xiaoming Lyu
- Department of Laboratory Medicine, The Third Affiliated Hospital, Southern Medical University, Guangzhou, China.
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75
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Sernicola A, Russo I, Alaibac M. Small-molecule-based immunotherapy for immunologically mediated skin conditions. Immunotherapy 2020; 12:417-429. [PMID: 32308089 DOI: 10.2217/imt-2019-0190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A better understanding of the molecular pathogenesis of cutaneous immune disorders, together with advances in pharmaceutical drug development, led to the introduction of small-molecule inhibitors in the therapeutic management of a large spectrum of skin immune conditions. Small molecules are agents with a low molecular weight that are capable of affecting proinflammatory pathways through modulation of intracellular targets. These agents promise to improve the therapeutic management of many skin immune disorders due to their easy administration, high bioavailability and favorable safety profile. Here, we review the major small-molecule inhibitors targeting receptor-associated kinases, second messengers and transcription factors in development for the treatment of cutaneous immune conditions.
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Affiliation(s)
- Alvise Sernicola
- Unit of Dermatology, University of Padua, Via Gallucci 4, 35128 Padova, Italy
| | - Irene Russo
- Unit of Dermatology, University of Padua, Via Gallucci 4, 35128 Padova, Italy
| | - Mauro Alaibac
- Unit of Dermatology, University of Padua, Via Gallucci 4, 35128 Padova, Italy
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76
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Morris G, Maes M, Berk M, Carvalho AF, Puri BK. Nutritional ketosis as an intervention to relieve astrogliosis: Possible therapeutic applications in the treatment of neurodegenerative and neuroprogressive disorders. Eur Psychiatry 2020; 63:e8. [PMID: 32093791 PMCID: PMC8057392 DOI: 10.1192/j.eurpsy.2019.13] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Nutritional ketosis, induced via either the classical ketogenic diet or the use of emulsified medium-chain triglycerides, is an established treatment for pharmaceutical resistant epilepsy in children and more recently in adults. In addition, the use of oral ketogenic compounds, fractionated coconut oil, very low carbohydrate intake, or ketone monoester supplementation has been reported to be potentially helpful in mild cognitive impairment, Parkinson’s disease, schizophrenia, bipolar disorder, and autistic spectrum disorder. In these and other neurodegenerative and neuroprogressive disorders, there are detrimental effects of oxidative stress, mitochondrial dysfunction, and neuroinflammation on neuronal function. However, they also adversely impact on neurone–glia interactions, disrupting the role of microglia and astrocytes in central nervous system (CNS) homeostasis. Astrocytes are the main site of CNS fatty acid oxidation; the resulting ketone bodies constitute an important source of oxidative fuel for neurones in an environment of glucose restriction. Importantly, the lactate shuttle between astrocytes and neurones is dependent on glycogenolysis and glycolysis, resulting from the fact that the astrocytic filopodia responsible for lactate release are too narrow to accommodate mitochondria. The entry into the CNS of ketone bodies and fatty acids, as a result of nutritional ketosis, has effects on the astrocytic glutamate–glutamine cycle, glutamate synthase activity, and on the function of vesicular glutamate transporters, EAAT, Na+, K+-ATPase, Kir4.1, aquaporin-4, Cx34 and KATP channels, as well as on astrogliosis. These mechanisms are detailed and it is suggested that they would tend to mitigate the changes seen in many neurodegenerative and neuroprogressive disorders. Hence, it is hypothesized that nutritional ketosis may have therapeutic applications in such disorders.
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Affiliation(s)
- Gerwyn Morris
- Deakin University, IMPACT Strategic Research Centre, Barwon Health, School of Medicine, Geelong, Victoria, Australia
| | - Michael Maes
- Deakin University, IMPACT Strategic Research Centre, Barwon Health, School of Medicine, Geelong, Victoria, Australia.,Department of Psychiatry, Chulalongkorn University, Faculty of Medicine, Bangkok, Thailand
| | - Michael Berk
- Deakin University, IMPACT Strategic Research Centre, Barwon Health, School of Medicine, Geelong, Victoria, Australia.,Deakin University, CMMR Strategic Research Centre, School of Medicine, Geelong, Victoria, Australia.,Orygen, The National Centre of Excellence in Youth Mental Health, The Department of Psychiatry and the Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - André F Carvalho
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada
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77
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Inami Y, Uta D, Andoh T. Neuronal hyperexcitability and astrocyte activation in spinal dorsal horn of a dermatitis mouse model with cutaneous hypersensitivity. Neurosci Lett 2020; 720:134784. [PMID: 31987915 DOI: 10.1016/j.neulet.2020.134784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/11/2020] [Accepted: 01/23/2020] [Indexed: 10/25/2022]
Abstract
Cleaning products such as soaps, shampoos, and detergents are comprised mainly of surfactants, agents known to cause dermatitis and cutaneous hypersensitivity characterized by itching, stinging, and burning of the skin and scalp. However, the mechanisms underlying surfactant-induced cutaneous hypersensitivity remain unclear. In the present study, we investigated the mechanisms of cutaneous hypersensitivity in mice treated with the detergent sodium dodecyl sulfate (SDS). Repeated SDS application to the skin induced inflammation, xeroderma, and elongation of peripheral nerves into the epidermis. The number of neurons immunopositive for c-Fos, a well known marker of neural activity, was substantially higher (+441%) in spinal dorsal horn (SDH) lamina I-II (but not lamina III-VI) of SDS-treated mice compared to vehicle-treated mice. In vivo extracellular recording revealed enhanced spontaneous (+64%) and non-noxious mechanical stimulation-evoked firing (+139%) of SDH lamina I-II neurons in SDS-treated mice, and stimulation-evoked neuronal firing was sustained (+5333%) even after stimulation. The number of GFAP-positive (activated) astrocytes, but not Iba1-positive microglia, was also elevated (+137%) in SDH lamina I-II of SDS-treated mice compared to vehicle-treated mice. Peripheral nerve elongation and hyperexcitability of afferent or SDH neurons, possible associated with the activation of spinal astrocytes, may underlie cutaneous hypersensitivity induced by surfactants.
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Affiliation(s)
- Yoshihiro Inami
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan; Advanced Research Laboratory, Hoyu Co., Ltd., Nagakute, Aichi, Japan.
| | - Daisuke Uta
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Tsugunobu Andoh
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
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78
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Kushnir V, Dmytrenko S, Katilov O, Kushnir N. Itching as the onset of pain (part 1). PAIN MEDICINE 2020. [DOI: 10.31636/pmjua.v4i4.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
PAIN is a psychophysiological reaction of an organism that occurs with severe irritation of the sensitive nerve endings embedded in organs and tissues. And also pain is the body’s protective reaction. It is signaling about a discomfort and triggers an appropriate response by the body to eliminate the cause of the pain. Pain is one of the earliest symptoms of some diseases [84].
ITCHING – an unpleasant sensation of irritation, heartburn and tingling in any area of the skin caused by various factors (exposure to chemicals, bacteria, parasites). This feeling is often manifested by the urgent need to rub or scratch some areas of the skin (or mucous membrane) [85].
When considering the pathogenesis of these concepts, a sufficiently large resemblance to the realization of mechanisms of origin, or a certain identity thereof is revealed. The question naturally arises whether itching is an early manifestation of pain, especially in those groups of diseases that are not characterized by pain.
Pathology of the hematopoietic system is not accompanied by a symptom such as pain. But for conditions such as iron overload, iron deficiency or polycythemia, itching is a clear symptom.
The unknown etiology of chronic itching of the skin is indicative of histological examination of the skin in order to exclude skin lymphoma. One of the least understood mechanisms of itching is itching associated with malignant solid tumors.
What pain that itching is a subjective sensation that can have an acute or chronic course, a clear intensity and a very significant impact on quality of life, especially in the case of comorbidity.
In addition, the question arises whether itching is an early manifestation of pain, especially in those groups of diseases that are not characterized by pain. How can a doctor manage itching effectively to prevent complications? To these and other questions, we have attempted to systematize the manifestations of itching in pathologies of organs and systems that are not traditionally accompanied by pain.
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79
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Koga K, Yamagata R, Kohno K, Yamane T, Shiratori-Hayashi M, Kohro Y, Tozaki-Saitoh H, Tsuda M. Sensitization of spinal itch transmission neurons in a mouse model of chronic itch requires an astrocytic factor. J Allergy Clin Immunol 2020; 145:183-191.e10. [DOI: 10.1016/j.jaci.2019.09.034] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/16/2019] [Accepted: 09/26/2019] [Indexed: 10/25/2022]
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80
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Resveratrol Downregulates STAT3 Expression and Astrocyte Activation in Primary Astrocyte Cultures of Rat. Neurochem Res 2019; 45:455-464. [PMID: 31853718 DOI: 10.1007/s11064-019-02936-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 12/09/2019] [Accepted: 12/15/2019] [Indexed: 12/23/2022]
Abstract
Astrocytes respond to all forms of central nervous system (CNS) insults by a process referred to as reactive astrogliosis. Inhibition of astrocyte growth and activation is an important strategy for promoting injured CNS repair. STAT3 (signal transducer and activator of transcription 3) is reported to be a critical regulator of astrogliosis, and resveratrol (RES, a dietary polyphenol) is considered to be a natural inhibitor of STAT3 expression and phosphorylation. In this study, we investigated the effects of RES on STAT3 expression and phosphorylation, and then on the proliferation and activation of astrocytes, a critical process in reactive astrogliosis, in rat primary cultured astrocytes and an in vitro scratch-wound model. RES downregulated the expression levels of STAT3, P-STAT3 and GFAP (glial fibrillary acidic protein) in cultured astrocytes. The positive index of Ki67 was apparently reduced in cultured astrocytes after RES treatment. Meanwhile, cultured astrocyte proliferation and activation were attenuated by RES. Moreover, in the established in vitro scratch-wound model the increased expression levels of STAT3, P-STAT3 and GFAP induced by scratching injury were also clearly inhibited by RES. In addition, the inhibitory effect of RES on cell proliferation was similar to that of AG490 (a selective inhibitor of STAT3 phosphorylation) and abrogated by Colivelin (a STAT3 activator) stimuli. Taken together, our data suggest that RES is able to inhibit reactive astrocyte proliferation and activation mainly via deactivating STAT3 pathway. So RES may have a therapeutic benefit for the treatment of the injured CNS.
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81
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Yosipovitch G, Berger T, Fassett MS. Neuroimmune interactions in chronic itch of atopic dermatitis. J Eur Acad Dermatol Venereol 2019; 34:239-250. [PMID: 31566796 PMCID: PMC7027518 DOI: 10.1111/jdv.15973] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 09/11/2019] [Indexed: 12/30/2022]
Abstract
Itch is a defining symptom of atopic dermatitis. Crosstalk between keratinocytes, the immune system and non‐histaminergic sensory nerves is responsible for the pathophysiology of chronic itch in atopic dermatitis. An expanding understanding of the contribution of the nervous system and its interaction with immune pathways in atopic itch are helping to identify new therapeutic strategies.
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Affiliation(s)
- G Yosipovitch
- Department of Dermatology and Cutaneous Surgery and Miami Itch Center, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - T Berger
- Department of Dermatology, School of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - M S Fassett
- Department of Dermatology, School of Medicine, University of California San Francisco, San Francisco, CA, USA
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82
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Walsh CM, Hill RZ, Schwendinger-Schreck J, Deguine J, Brock EC, Kucirek N, Rifi Z, Wei J, Gronert K, Brem RB, Barton GM, Bautista DM. Neutrophils promote CXCR3-dependent itch in the development of atopic dermatitis. eLife 2019; 8:48448. [PMID: 31631836 PMCID: PMC6884397 DOI: 10.7554/elife.48448] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/17/2019] [Indexed: 12/12/2022] Open
Abstract
Chronic itch remains a highly prevalent disorder with limited treatment options. Most chronic itch diseases are thought to be driven by both the nervous and immune systems, but the fundamental molecular and cellular interactions that trigger the development of itch and the acute-to-chronic itch transition remain unknown. Here, we show that skin-infiltrating neutrophils are key initiators of itch in atopic dermatitis, the most prevalent chronic itch disorder. Neutrophil depletion significantly attenuated itch-evoked scratching in a mouse model of atopic dermatitis. Neutrophils were also required for several key hallmarks of chronic itch, including skin hyperinnervation, enhanced expression of itch signaling molecules, and upregulation of inflammatory cytokines, activity-induced genes, and markers of neuropathic itch. Finally, we demonstrate that neutrophils are required for induction of CXCL10, a ligand of the CXCR3 receptor that promotes itch via activation of sensory neurons, and we find that that CXCR3 antagonism attenuates chronic itch. Chronic itch is a debilitating disorder that can last for months or years. Eczema, or atopic dermatitis, is the most common cause for chronic itch, affecting one in ten people worldwide. Many treatments for the condition are ineffective, and the exact cause of the disease is unknown, but many different types of cells are likely involved. These include skin cells and inflammation-promoting immune cells, as well as nerve cells that detect inflammation, relay itch and pain information to the brain, and regulate the immune system. Learning more about how these cells interact in eczema may help scientists find better treatments for the condition. So far, a lot of research has focused on static ‘snapshots’ of mature eczema lesions from human skin or animal models. These studies have identified abnormalities in genes or cells, but have not revealed how these genes and cells interact over time to cause chronic itch and inflammation. Now, Walsh et al. reveal that immune cells called neutrophils trigger chronic itch in eczema. The experiments involved mice with a condition that mimics eczema, and showed that removing the neutrophils in these mice alleviated their itching. They also showed that dramatic and rapid changes occur in the nervous system of mice suffering from the eczema-like condition. For example, excess nerves grow in the animals’ damaged skin, genes in the nerves that detect sensations become hyperactive, and changes occur in the spinal cord that have been linked to nerve pain. When neutrophils are absent, these changes do not take place. These findings show that neutrophils play a key role in chronic itch and inflammation in eczema. Drugs that target neutrophils, which are already used to treat other diseases, might help with chronic itch, but they would need to be tested before they can be used on people with eczema.
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Affiliation(s)
- Carolyn M Walsh
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Rose Z Hill
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | | | - Jacques Deguine
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Emily C Brock
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Natalie Kucirek
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Ziad Rifi
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Jessica Wei
- Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, United States
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, United States
| | - Rachel B Brem
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, United States.,Buck Institute for Research on Aging, Novato, United States
| | - Gregory M Barton
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Diana M Bautista
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
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83
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Li D, Liu X, Liu T, Liu H, Tong L, Jia S, Wang YF. Neurochemical regulation of the expression and function of glial fibrillary acidic protein in astrocytes. Glia 2019; 68:878-897. [PMID: 31626364 DOI: 10.1002/glia.23734] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/27/2019] [Accepted: 09/17/2019] [Indexed: 12/30/2022]
Abstract
Glial fibrillary acidic protein (GFAP), a type III intermediate filament, is a marker of mature astrocytes. The expression of GFAP gene is regulated by many transcription factors (TFs), mainly Janus kinase-2/signal transducer and activator of transcription 3 cascade and nuclear factor κ-light-chain-enhancer of activated B cell signaling. GFAP expression is also modulated by protein kinase and other signaling molecules that are elicited by neuronal activity and hormones. Abnormal expression of GFAP proteins occurs in neuroinflammation, neurodegeneration, brain edema-eliciting diseases, traumatic brain injury, psychiatric disorders and others. GFAP, mainly in α-isoform, is the major component of cytoskeleton and the scaffold of astrocytes, which is essential for the maintenance of astrocytic structure and shape. GFAP also has highly morphological plasticity because of its quick changes in assembling and polymerizing states in response to environmental challenges. This plasticity and its corresponding cellular morphological changes endow astrocytes the functions of physical barrier between adjacent neurons and stabilizer of extracellular environment. Moreover, GFAP colocalizes and even molecularly associates with many functional molecules. This feature allows GFAP to function as a platform for direct interactions between different molecules. Last, GFAP involves transportation and localization of other functional proteins and thus serves as a protein transport guide in astrocytes. This guiding role of GFAP involves an elastic retraction and extension cytoskeletal network that couples with GFAP reassembling, transporting, and membrane protein recycling machinery. This paper reviews our current understanding of the expression and functions of GFAP as well as their regulation.
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Affiliation(s)
- Dongyang Li
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Xiaoyu Liu
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Tianming Liu
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Haitao Liu
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Li Tong
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Yu-Feng Wang
- Department of Physiology, Harbin Medical University, Harbin, China
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84
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Ishiuji Y. Addiction and the itch‐scratch cycle. What do they have in common? Exp Dermatol 2019; 28:1448-1454. [DOI: 10.1111/exd.14029] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 07/15/2019] [Accepted: 08/26/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Yozo Ishiuji
- Department of Dermatology The Jikei University School of Medicine Tokyo Japan
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85
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Abstract
Astrocytes are critical for maintaining the homeostasis of the CNS. Increasing evidence suggests that a number of neurological and neuropsychiatric disorders, including chronic pain, may result from astrocyte 'gliopathy'. Indeed, in recent years there has been substantial progress in our understanding of how astrocytes can regulate nociceptive synaptic transmission via neuronal-glial and glial-glial cell interactions, as well as the involvement of spinal and supraspinal astrocytes in the modulation of pain signalling and the maintenance of neuropathic pain. A role of astrocytes in the pathogenesis of chronic itch is also emerging. These developments suggest that targeting the specific pathways that are responsible for astrogliopathy may represent a novel approach to develop therapies for chronic pain and chronic itch.
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86
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Yosipovitch G, Rosen JD, Hashimoto T. Itch: From mechanism to (novel) therapeutic approaches. J Allergy Clin Immunol 2019; 142:1375-1390. [PMID: 30409247 DOI: 10.1016/j.jaci.2018.09.005] [Citation(s) in RCA: 194] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/27/2018] [Accepted: 09/07/2018] [Indexed: 12/13/2022]
Abstract
Itch is a common sensory experience that is prevalent in patients with inflammatory skin diseases, as well as in those with systemic and neuropathic conditions. In patients with these conditions, itch is often severe and significantly affects quality of life. Itch is encoded by 2 major neuronal pathways: histaminergic (in acute itch) and nonhistaminergic (in chronic itch). In the majority of cases, crosstalk existing between keratinocytes, the immune system, and nonhistaminergic sensory nerves is responsible for the pathophysiology of chronic itch. This review provides an overview of the current understanding of the molecular, neural, and immune mechanisms of itch: beginning in the skin, proceeding to the spinal cord, and eventually ascending to the brain, where itch is processed. A growing understanding of the mechanisms of chronic itch is expanding, as is our pipeline of more targeted topical and systemic therapies. Our therapeutic armamentarium for treating chronic itch has expanded in the last 5 years, with developments of topical and systemic treatments targeting the neural and immune systems.
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Affiliation(s)
- Gil Yosipovitch
- Department of Dermatology and Cutaneous Surgery and Miami Itch Center Miller School of Medicine University of Miami, Miami, Fla.
| | - Jordan Daniel Rosen
- Department of Dermatology and Cutaneous Surgery and Miami Itch Center Miller School of Medicine University of Miami, Miami, Fla
| | - Takashi Hashimoto
- Department of Dermatology and Cutaneous Surgery and Miami Itch Center Miller School of Medicine University of Miami, Miami, Fla
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87
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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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88
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Abstract
Atopic dermatitis (AD) is a chronic, inflammatory skin disease characterized by pruritus, inflammatory erythematous skin lesions, and skin-barrier defect. Current mainstay treatments of emollients, steroids, calcineurin inhibitors, and immunosuppressants have limited efficacy and potentially serious side effects. Recent advances and understanding of the pathogenesis of AD have resulted in new therapies that target specific pathways with increased efficacy and the potential for less systemic side effects. New FDA-approved therapies for AD are crisaborole and dupilumab. The JAK-STAT inhibitors (baricitinib, upadacitinib, PF-04965842, ASN002, tofacitinib, ruxolitinib, and delgocitinib) have the most promising results of the emerging therapies. Other drugs with potential include the aryl hydrocarbon receptor modulating agent tapinarof, the IL-4/IL-13 antagonists lebrikizumab and tralokinumab, and the IL-31Rα antagonist nemolizumab. In this review, new and emerging AD therapies will be discussed along with their mechanisms of action and their potential based on clinical study data.
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Affiliation(s)
- Henry L Nguyen
- Department of Dermatology, Mayo Clinic, 200 1st Street SW, Rochester, MN, 55902, USA
| | - Katelyn R Anderson
- Department of Dermatology, Mayo Clinic, 200 1st Street SW, Rochester, MN, 55902, USA
| | - Megha M Tollefson
- Department of Dermatology, Mayo Clinic, 200 1st Street SW, Rochester, MN, 55902, USA.
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89
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Abstract
Supplemental Digital Content is Available in the Text. Anxiety predicts onset of knee pain and drives greater osteoarthritis pain in humans. Our validated preclinical model identifies supraspinal astrocytosis as a potential mechanism. Anxiety and depression are associated with increased pain responses in chronic pain states. The extent to which anxiety drives chronic pain, or vice versa, remains an important question that has implications for analgesic treatment strategies. Here, the effect of existing anxiety on future osteoarthritis (OA) pain was investigated, and potential mechanisms were studied in an animal model. Pressure pain detection thresholds, anxiety, and depression were assessed in people with (n = 130) or without (n = 100) painful knee OA. Separately, knee pain and anxiety scores were also measured twice over 12 months in 4730 individuals recruited from the general population. A preclinical investigation of a model of OA pain in normo-anxiety Sprague-Dawley (SD) and high-anxiety Wistar Kyoto (WKY) rats assessed underlying neurobiological mechanisms. Higher anxiety, independently from depression, was associated with significantly lower pressure pain detection thresholds at sites local to (P < 0.01) and distant from (P < 0.05) the painful knee in patients with OA. Separately, high anxiety scores predicted increased risk of knee pain onset in 3274 originally pain-free people over the 1-year period (odds ratio = 1.71; 95% confidence interval = 1.25-2.34, P < 0.00083). Similarly, WKY rats developed significantly lower ipsilateral and contralateral hind paw withdrawal thresholds in the monosodium iodoacetate model of OA pain, compared with SD rats (P = 0.0005). Linear regressions revealed that baseline anxiety-like behaviour was predictive of lowered paw withdrawal thresholds in WKY rats, mirroring the human data. This augmented pain phenotype was significantly associated with increased glial fibrillary acidic protein immunofluorescence in pain-associated brain regions, identifying supraspinal astrocyte activation as a significant mechanism underlying anxiety-augmented pain behaviour.
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90
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Liu BW, Li ZX, He ZG, Wang Q, Liu C, Zhang XW, Yang H, Xiang HB. Altered expression of itch‑related mediators in the lower cervical spinal cord in mouse models of two types of chronic itch. Int J Mol Med 2019; 44:835-846. [PMID: 31257468 PMCID: PMC6657970 DOI: 10.3892/ijmm.2019.4253] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 06/13/2019] [Indexed: 01/08/2023] Open
Abstract
In this study, we focused on several itch-related molecules and receptors in the spinal cord with the goal of clarifying the specific mediators that regulate itch sensation. We investigated the involvement of serotonin receptors, opioid receptors, glia cell markers and chemokines (ligands and receptors) in models of acetone/ether/water (AEW)- and diphenylcyclopropenone (DCP)-induced chronic itch. Using reverse transcription-quantitative polymerase chain reaction, we examined the expression profiles of these mediators in the lower cervical spinal cord (C5-8) of two models of chronic itch. We found that the gene expression levels of opioid receptor mu 1 (Oprm1), 5-hydroxytryptamine receptor 1A (Htr1a) and 5-hydroxytryptamine receptor 6 (Htr6) were upregulated. Among the chemokines, the expression levels of C-C motif chemokine ligand (Ccl)21, Cxcl3 and Cxcl16 and their receptors, Ccr7, Cxcr2 and Cxcr6, were simultaneously upregulated in the spinal cords of the mice in both models of chronic itch. By contrast, the expression levels of Ccl2, Ccl3, Ccl4 and Ccl22 were downregulated. These findings indicate that multiple mediators, such as chemokines in the spinal cord, are altered and may be central candidates in further research into the mechanisms involved in the development of chronic itch.
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Affiliation(s)
- Bao-Wen Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Zhi-Xiao Li
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Zhi-Gang He
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Qian Wang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Cheng Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Xian-Wei Zhang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Hui Yang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Hong-Bing Xiang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
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91
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Nelson NA, Wang X, Cook D, Carey EM, Nimmerjahn A. Imaging spinal cord activity in behaving animals. Exp Neurol 2019; 320:112974. [PMID: 31175843 DOI: 10.1016/j.expneurol.2019.112974] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/02/2019] [Accepted: 06/04/2019] [Indexed: 01/06/2023]
Abstract
The spinal cord is the primary neurological link between the brain and peripheral organs. How important it is in everyday life is apparent in patients with spinal cord injury or motoneuron disease, who have dramatically reduced musculoskeletal control or capacity to sense their environment. Despite its crucial role in sensory and motor processing little is known about the cellular and molecular signaling events that underlie spinal cord function under naturalistic conditions. While genetic, electrophysiological, pharmacological, and circuit tracing studies have revealed important roles for different molecularly defined neurons, these approaches insufficiently describe the moment-to-moment neuronal and non-neuronal activity patterns that underlie sensory-guided motor behaviors in health and disease. The recent development of imaging methods for real-time interrogation of cellular activity in the spinal cord of behaving mice has removed longstanding technical obstacles to spinal cord research and allowed new insight into how different cell types encode sensory information from mechanoreceptors and nociceptors in the skin. Here, we review the current state-of-the-art in interrogating cellular and microcircuit function in the spinal cord of behaving mammals and discuss current opportunities and technological challenges.
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Affiliation(s)
- Nicholas A Nelson
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Biologial Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92037, USA
| | - Xiang Wang
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Daniela Cook
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Erin M Carey
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Axel Nimmerjahn
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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92
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Du L, Hu X, Yang W, Yasheng H, Liu S, Zhang W, Zhou Y, Cui W, Zhu J, Qiao Z, Maoying Q, Chu Y, Zhou H, Wang Y, Mi W. Spinal IL-33/ST2 signaling mediates chronic itch in mice through the astrocytic JAK2-STAT3 cascade. Glia 2019; 67:1680-1693. [PMID: 31087583 DOI: 10.1002/glia.23639] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 03/29/2019] [Accepted: 04/23/2019] [Indexed: 12/22/2022]
Abstract
Interleukin-33 (IL-33) and its receptor ST2 contribute to spinal glial activation and chronic pain. A recent study showed that peripheral IL-33 plays a pivotal role in the pathogenesis of chronic itch induced by poison ivy. However, how IL-33/ST2 signaling in the spinal cord potentially mediates chronic itch remains elusive. Here, we determined that St2-/- substantially reduced scratching behaviors in 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD) as well as acetone and diethylether followed by water-induced dry skin in mice. Intrathecal administration of the neutralizing anti-ST2 or anti-IL-33 antibody remarkably decreased the scratching response in DNFB-induced ACD mice. Expression of spinal IL-33 and ST2 significantly increased in ACD mice, as evidenced by increased mRNA and protein levels. Immunofluorescence and in situ hybridization demonstrated that increased expression of spinal IL-33 was predominant in oligodendrocytes and astrocytes, whereas ST2 was mainly expressed in astrocytes. Further studies showed that in ACD mice, the activation of astrocytes and increased phosphorylation of signal transducer and activator of transcription 3 (STAT3) were markedly attenuated by St2-/- . Intrathecal injection of Janus Kinase 2 Inhibitor AG490 significantly alleviated scratching behaviors in ACD mice. rIL-33 pretreatment exacerbated gastrin-releasing peptide (GRP)-evoked scratching behaviors. This increased gastrin-releasing peptide receptor (GRPR) expression was abolished by St2-/- . Tnf-α upregulation was suppressed by St2-/- . Our results indicate that the spinal IL-33/ST2 signaling pathway contributes to chronic itch via astrocytic JAK2-STAT3 cascade activation, promoting TNF-α release to regulate the GRP/GRPR signaling-related itch response. Thus, these findings provide a potential therapeutic option for treating chronic pruritus.
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Affiliation(s)
- Lixia Du
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Xueming Hu
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Wei Yang
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Hanikezi Yasheng
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Shenbin Liu
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Wenwen Zhang
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Yang Zhou
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Wenqiang Cui
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Jianyu Zhu
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Zheng Qiao
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Qiliang Maoying
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Yuxia Chu
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Hong Zhou
- Department of Immunology, Nanjing Medical University, Nanjing, People's Republic of China
| | - Yanqing Wang
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Wenli Mi
- Department of Integrative Medicine and Neurobiology, Institutes of Integrative Medicine, School of Basic Medical Sciences, Institutes of Brain Science, Brain Science Collaborative Innovation Center, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
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93
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Su XY, Chen M, Yuan Y, Li Y, Guo SS, Luo HQ, Huang C, Sun W, Li Y, Zhu MX, Liu MG, Hu J, Xu TL. Central Processing of Itch in the Midbrain Reward Center. Neuron 2019; 102:858-872.e5. [PMID: 31000426 DOI: 10.1016/j.neuron.2019.03.030] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 12/28/2018] [Accepted: 03/19/2019] [Indexed: 10/27/2022]
Abstract
Itch is an aversive sensation that evokes a desire to scratch. Paradoxically, scratching the itch also produces a hedonic experience. The specific brain circuits processing these different aspects of itch, however, remain elusive. Here, we report that GABAergic (GABA) and dopaminergic (DA) neurons in the ventral tegmental area (VTA) are activated with different temporal patterns during acute and chronic itch. DA neuron activation lags behind GABA neurons and is dependent on scratching of the itchy site. Optogenetic manipulations of VTA GABA neurons rapidly modulated scratching behaviors through encoding itch-associated aversion. In contrast, optogenetic manipulations of VTA DA neurons revealed their roles in sustaining recurrent scratching episodes through signaling scratching-induced reward. A similar dichotomy exists for the role of VTA in chronic itch. These findings advance understanding of circuit mechanisms of the unstoppable itch-scratch cycles and shed important insights into chronic itch therapy.
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Affiliation(s)
- Xin-Yu Su
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Ming Chen
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China
| | - Yuan Yuan
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Ying Li
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Su-Shan Guo
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Huo-Qing Luo
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Chen Huang
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Wenzhi Sun
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Yong Li
- Collaborative Innovation Center for Brain Science, Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai 201210, China
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ming-Gang Liu
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
| | - Ji Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai 201210, China.
| | - Tian-Le Xu
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Research Center for Brain Science and Brain-Inspired Intelligence, Shanghai 201210, China.
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94
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Abstract
Atopic dermatitis (AD) is the most common chronic inflammatory skin disease. Genetic predisposition, epidermal barrier disruption, and dysregulation of the immune system are some of the critical components of AD. An impaired skin barrier may be the initial step in the development of the atopic march as well as AD, which leads to further skin inflammation and allergic sensitization. Type 2 cytokines as well as interleukin 17 and interleukin 22 contribute to skin barrier dysfunction and the development of AD. New insights into the pathophysiology of AD have focused on epidermal lipid profiles, neuroimmune interactions, and microbial dysbiosis. Newer therapeutic strategies focus on improving skin barrier function and targeting polarized immune pathways found in AD. Further understanding of AD pathophysiology will allow us to achieve a more precision medicine approach to the prevention and the treatment of AD.
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Affiliation(s)
- Jihyun Kim
- From the Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Byung Eui Kim
- Department of Pediatrics, National Jewish Health, Denver, Colorado
| | - Donald Y M Leung
- Department of Pediatrics, National Jewish Health, Denver, Colorado
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95
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Relationship between the Degrees of Itch and Serum Lipocalin-2 Levels in Patients with Psoriasis. J Immunol Res 2019; 2019:8171373. [PMID: 30805373 PMCID: PMC6360588 DOI: 10.1155/2019/8171373] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 11/29/2018] [Indexed: 11/18/2022] Open
Abstract
Background Lipocalin-2 (LCN2), a protein secreted mainly by activated neutrophils, has been associated with neurodegeneration, obesity, and inflammatory responses. Serum LCN2 concentration has been reported elevated in patients with psoriasis, but lower in patients with atopic dermatitis (AD). Spinal astrocyte-derived LCN2 was found to be involved in enhancement of itch in a mouse model of AD. However, the relationship between LCN2 and itch in patients with psoriasis has not been determined. Objective. This study examined the correlation between serum LCN2 levels and the degrees of itch in patients with psoriasis. Methods Serum LCN2 concentrations were measured by enzyme-linked immunosorbent assays (ELISA) in patients with psoriasis and AD and in healthy controls. The degree of itch was assessed using a visual analog scale (VAS), and disease severity was determined by measuring psoriasis area and severity index (PASI) and scoring atopic dermatitis (SCORAD). Correlations among serum LCN2 level, VAS, PASI, and SCORAD were analyzed statistically. We further examined the serum LCN levels in psoriasis patients before and after biological treatment. Results Serum LCN2 concentrations were significantly higher in patients with psoriasis and AD than those in healthy controls. In patients with psoriasis, serum LCN2 concentrations were significantly correlated with VAS, but not with PASI. In contrast, serum LCN2 concentrations did not correlate with VAS or SCORAD in patients with AD. Serum LCN2 levels in psoriasis patients significantly decreased after the biological treatment along with improvement of VAS. Conclusion Serum LCN2 concentration is associated with the degree of itch in patients with psoriasis, suggesting that serum LCN2 may be a useful clinical marker for itch in psoriasis.
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96
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Shiratori-Hayashi M, Hasegawa A, Toyonaga H, Andoh T, Nakahara T, Kido-Nakahara M, Furue M, Kuraishi Y, Inoue K, Dong X, Tsuda M. Role of P2X3 receptors in scratching behavior in mouse models. J Allergy Clin Immunol 2018; 143:1252-1254.e8. [PMID: 30452925 DOI: 10.1016/j.jaci.2018.10.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 10/11/2018] [Accepted: 10/19/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Miho Shiratori-Hayashi
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Ayumi Hasegawa
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Honami Toyonaga
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Tsugunobu Andoh
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Takeshi Nakahara
- Department of Dermatology, Graduate School of Medicine, Kyushu University, Fukuoka, Japan
| | - Makiko Kido-Nakahara
- Department of Dermatology, Graduate School of Medicine, Kyushu University, Fukuoka, Japan
| | - Masutaka Furue
- Department of Dermatology, Graduate School of Medicine, Kyushu University, Fukuoka, Japan
| | - Yasushi Kuraishi
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Kazuhide Inoue
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Md
| | - Makoto Tsuda
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
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97
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Ajayi AAL. Itching, chloroquine, and malaria: a review of recent molecular and neuroscience advances and their contribution to mechanistic understanding and therapeutics of chronic non-histaminergic pruritus. Int J Dermatol 2018; 58:880-891. [PMID: 30362504 DOI: 10.1111/ijd.14252] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/23/2018] [Accepted: 08/31/2018] [Indexed: 12/20/2022]
Abstract
Chloroquine (CQ) is an antimalarial drug that elicits severe pruritus in black Africans with malaria fever. This acute itching (2-7 days duration) exhibits age dependency and a racial and genetic predilection. CQ itch is non-histaminergic, which makes it both a good model and a tool to probe the mechanisms of chronic itch. This review focuses on recently discovered mechanisms, neuroscience, mediators, and receptors that are implicated in molecular studies of CQ pruritus. CQ pruritus mechanisms are also compared to that of itching following other systemic diseases, such as chronic kidney disease, chronic liver disease, skin disorders, and burns. There are striking similarities between CQ itching pathways and other chronic itch secondary to systemic disease with or without skin lesions, which have not been previously highlighted. Prominent among these are the shared roles of skin, neural and spinal μ opiate receptors, kappa opiate receptor, nitric oxide, serotonin via 5HT1B/D receptors, cytokines, especially interleukins, and tumor necrosis factor. There is elaborate "cross talk" among the diverse mediators and receptors involved in CQ-induced pruritus. CQ also binds to the mas-related G protein coupled receptors MrgprA3/MrgprX1 present in a small proportion (4-5%) of dorsal root ganglion neurons and skin. The mrgprA3 CQ receptors are coupled to PLC-β3 and a chloride channel to initiate skin itch action potentials in C nerve fibers. Mrgpra3/X1 couples to TRPA1 for calcium influx into neuronal cells at noncutaneous sites. Central CQ itch occurs via gastrin-related peptide (GRP) and its receptor (GRPR) in the dorsal spinothalamic tracts, as well as glutamic mediated GRP projection to parabrachial nucleus. The possibility of chronic itch therapy based on personalized medicine, genetics, and transcriptomics or the use of itch "polypill/polycream" are discussed.
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Affiliation(s)
- Adesuyi A L Ajayi
- Department of Medicine, Division of Clinical Pharmacology, Baylor College of Medicine, Houston, TX, USA
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98
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Nakahara T, Furue M. Nemolizumab and Atopic Dermatitis: the Interaction Between Interleukin-31 and Interleukin-31 Receptor as a Potential Therapeutic Target for Pruritus in Patients With Atopic Dermatitis. CURRENT TREATMENT OPTIONS IN ALLERGY 2018. [DOI: 10.1007/s40521-018-0191-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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99
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Steinhoff M, Schmelz M, Szabó IL, Oaklander AL. Clinical presentation, management, and pathophysiology of neuropathic itch. Lancet Neurol 2018; 17:709-720. [PMID: 30033061 DOI: 10.1016/s1474-4422(18)30217-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 05/15/2018] [Accepted: 06/01/2018] [Indexed: 12/19/2022]
Abstract
Unlike conventional itch, neuropathic itch develops in normal skin from excess peripheral firing or dampened central inhibition of itch pathway neurons. Neuropathic itch is a symptom of the same central and peripheral nervous system disorders that cause neuropathic pain, such as sensory polyneuropathy, radiculopathy, herpes zoster, stroke, or multiple sclerosis, and lesion location affects symptoms more than aetiology. The causes of neuropathic itch are heterogeneous, and thus diagnosis is based primarily on recognising characteristic, disease-specific clinical presentations. However, the diagnosis of neuropathic itch is challenging, different subforms exist (eg, focal vs widespread, peripheral vs central), and the mechanisms of neuropathic itch are poorly understood, resulting in reduced treatment availability. Currently available strategies include treating or preventing causal diseases, such as diabetes or herpes zoster, and topical or systemic medications that calm excess neuronal firing. Discovery of itch mediators such as gastrin releasing peptide, receptors (eg, neurokinin-1), and pathways (eg, Janus kinases) might encourage much needed new research into targeted treatments of neuropathic itch.
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Affiliation(s)
- Martin Steinhoff
- Department of Dermatology and Venereology, Hamad Medical Corporation, Doha, Qatar; HMC Translational Research Institute, Hamad Medical Corporation, Doha, Qatar; Weill Cornell Medicine-Qatar, Doha, Qatar; College of Medicine, Qatar University, Medical School, Doha, Qatar.
| | - Martin Schmelz
- Department of Experimental Pain Research, CBTM Mannheim, Heidelberg University, Mannheim, Germany
| | - Imre Lőrinc Szabó
- Department of Dermatology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Anne Louise Oaklander
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Neuropathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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100
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Abstract
Chronic, persistent itch is a devastating symptom that causes much suffering. In recent years, there has been great progress made in understanding the molecules, cells, and circuits underlying itch sensation. Once thought to be carried by pain-sensing neurons, itch is now believed to be capable of being transmitted by dedicated sensory labeled lines. Members of the Mas-related G protein-coupled receptor (Mrgpr) family demarcate an itch-specific labeled line in the peripheral nervous system. In the spinal cord, the expression of other proteins identifies additional populations of itch-dedicated sensory neurons. However, as evidence for labeled-line coding has mounted, studies promoting alternative itch-coding strategies have emerged, complicating our understanding of the neural basis of itch. In this review, we cover the molecules, cells, and circuits related to understanding the neural basis of itch, with a focus on the role of Mrgprs in mediating itch sensation.
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Affiliation(s)
- James Meixiong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21205, USA; ,
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience and the Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21205, USA; , .,Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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