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Ding H, Zhou L, Zhou J, Feng J. Peripheral Mechanisms of Mechanical Itch. J Invest Dermatol 2024; 144:1449-1453. [PMID: 38206270 DOI: 10.1016/j.jid.2023.10.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/25/2023] [Accepted: 10/31/2023] [Indexed: 01/12/2024]
Abstract
Mechanical itch, which is defined as an itch sensation caused by innocuous mechanical force, may warn of the potential risk in the skin. The increased mechanosensitivity in sensory neurons may cause scratch-induced itch and promote the transition from acute itch to chronic itch. Recent studies have not only expanded our knowledge about the neuronal circuits in the CNS but have also highlighted the importance of the peripheral epithelia-immune-neuronal crosstalk in the development of mechanical itch. In this review, we will summarize related findings about the molecular and cellular mechanisms of mechanical itch in the skin.
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Affiliation(s)
- Huijuan Ding
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Liqin Zhou
- State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jiaying Zhou
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jing Feng
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China; State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, China; University of Chinese Academy of Sciences, Beijing, China.
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2
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Hu Z, Huang X, Liu J, Wang Z, Xi Y, Yang Y, Lin S, So KF, Huang L, Tao Q, Ren C. A visual circuit related to the parabrachial nucleus for the antipruritic effects of bright light treatment. Cell Rep 2024; 43:114356. [PMID: 38865246 DOI: 10.1016/j.celrep.2024.114356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 05/11/2024] [Accepted: 05/29/2024] [Indexed: 06/14/2024] Open
Abstract
In addition to its role in vision, light also serves non-image-forming visual functions. Despite clinical evidence suggesting the antipruritic effects of bright light treatment, the circuit mechanisms underlying the effects of light on itch-related behaviors remain poorly understood. In this study, we demonstrate that bright light treatment reduces itch-related behaviors in mice through a visual circuit related to the lateral parabrachial nucleus (LPBN). Specifically, a subset of retinal ganglion cells (RGCs) innervates GABAergic neurons in the ventral lateral geniculate nucleus and intergeniculate leaflet (vLGN/IGL), which subsequently inhibit CaMKIIα+ neurons in the LPBN. Activation of both the vLGN/IGL-projecting RGCs and the vLGN/IGL-to-LPBN projections is sufficient to reduce itch-related behaviors induced by various pruritogens. Importantly, we demonstrate that the antipruritic effects of bright light treatment rely on the activation of the retina-vLGN/IGL-LPBN pathway. Collectively, our findings elucidate a visual circuit related to the LPBN that underlies the antipruritic effects of bright light treatment.
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Affiliation(s)
- Zhengfang Hu
- Department of Neurology and Stroke Center, First Affiliated Hospital of Jinan University, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong Key Laboratory of Non-human Primate Research, GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China
| | - Xiaodan Huang
- Department of Neurology and Stroke Center, First Affiliated Hospital of Jinan University, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong Key Laboratory of Non-human Primate Research, GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China
| | - Jianyu Liu
- Department of Neurology and Stroke Center, First Affiliated Hospital of Jinan University, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong Key Laboratory of Non-human Primate Research, GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China
| | - Ziyang Wang
- Department of Neurology and Stroke Center, First Affiliated Hospital of Jinan University, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong Key Laboratory of Non-human Primate Research, GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China
| | - Yue Xi
- Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China
| | - Yan Yang
- Department of Neurology and Stroke Center, First Affiliated Hospital of Jinan University, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong Key Laboratory of Non-human Primate Research, GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China
| | - Song Lin
- Physiology Department, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Kwok-Fai So
- Department of Neurology and Stroke Center, First Affiliated Hospital of Jinan University, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong Key Laboratory of Non-human Primate Research, GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China; Center for Brain Science and Brain-Inspired Intelligence, Guangdong-Hong Kong-Macao Greater Bay Area, Guangzhou 510515, China; Key Laboratory of Brain and Cognitive Science, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Lu Huang
- Department of Neurology and Stroke Center, First Affiliated Hospital of Jinan University, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong Key Laboratory of Non-human Primate Research, GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China.
| | - Qian Tao
- Department of Rehabilitation Medicine, First Affiliated Hospital of Jinan University, Department of Public Health and Preventive Medicine Psychology, School of Medicine, Jinan University, Guangzhou 510632, China.
| | - Chaoran Ren
- Department of Neurology and Stroke Center, First Affiliated Hospital of Jinan University, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong Key Laboratory of Non-human Primate Research, GHM Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China; Center for Brain Science and Brain-Inspired Intelligence, Guangdong-Hong Kong-Macao Greater Bay Area, Guangzhou 510515, China.
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3
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Inokuchi-Sakata S, Narita R, Takahashi Y, Ishiuji Y, Asahina A, Kato F. Region-specific activation in the accumbens nucleus by itch with modified scratch efficacy in mice - a model-free multivariate analysis. Mol Brain 2024; 17:27. [PMID: 38783364 PMCID: PMC11119306 DOI: 10.1186/s13041-024-01101-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024] Open
Abstract
Itch is a protective/defensive function with divalent motivational drives. Itch itself elicits an unpleasant experience, which triggers the urge to scratch, relieving the itchiness. Still, it can also result in dissatisfaction when the scratch is too intense and painful or unsatisfactory due to insufficient scratch effect. Therefore, it is likely that the balance between the unpleasantness/pleasure and satisfaction/unsatisfaction associated with itch sensation and scratching behavior is determined by complex brain mechanisms. The physiological/pathological mechanisms underlying this balance remain largely elusive. To address this issue, we targeted the "reward center" of the brain, the nucleus accumbens (NAc), in which itch-responsive neurons have been found in rodents. We examined how neurons in the NAc are activated or suppressed during histamine-induced scratching behaviors in mice. The mice received an intradermal injection of histamine or saline at the neck, and the scratching number was analyzed by recording the movement of the bilateral hind limbs for about 45 min after injection. To experimentally manipulate the scratch efficacy in these histamine models, we compared histamine's behavioral and neuronal effects between mice with intact and clipped nails on the hind paws. As expected, the clipping of the hind limb nail increased the number of scratches after the histamine injection. In the brains of mice exhibiting scratching behaviors, we analyzed the expression of the c-fos gene (Fos) as a readout of an immediate activation of neurons during itch/scratch and dopamine receptors (Drd1 and Drd2) using multiplex single-molecule fluorescence in situ hybridization (RNAscope) in the NAc and surrounding structures. We performed a model-free analysis of gene expression in geometrically divided NAc subregions without assuming the conventional core-shell divisions. The results indicated that even within the NAc, multiple subregions responded differentially to various itch/scratch conditions. We also found different clusters with neurons showing similar or opposite changes in Fos expression and the correlation between scratch number and Fos expression in different itch/scratch conditions. These regional differences and clusters would provide a basis for the complex role of the NAc and surrounding structures in encoding the outcomes of scratching behavior and itchy sensations.
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Affiliation(s)
- Sanae Inokuchi-Sakata
- Department of Dermatology, The Jikei University School of Medicine, Minato-Ku, Tokyo, 105-8461, Japan
- Department of Neuroscience, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan
| | - Ryo Narita
- Department of Neuroscience, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan
- Center for Neuroscience of Pain, The Jikei University School of Medicine, Minato-Ku, Tokyo, 105-8461, Japan
| | - Yukari Takahashi
- Department of Neuroscience, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan
- Center for Neuroscience of Pain, The Jikei University School of Medicine, Minato-Ku, Tokyo, 105-8461, Japan
| | - Yozo Ishiuji
- Department of Dermatology, The Jikei University School of Medicine, Minato-Ku, Tokyo, 105-8461, Japan
- Center for Neuroscience of Pain, The Jikei University School of Medicine, Minato-Ku, Tokyo, 105-8461, Japan
| | - Akihiko Asahina
- Department of Dermatology, The Jikei University School of Medicine, Minato-Ku, Tokyo, 105-8461, Japan
| | - Fusao Kato
- Department of Neuroscience, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan.
- Center for Neuroscience of Pain, The Jikei University School of Medicine, Minato-Ku, Tokyo, 105-8461, Japan.
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4
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Zheng J, Zhang XM, Tang W, Li Y, Wang P, Jin J, Luo Z, Fang S, Yang S, Wei Z, Song K, Huang Z, Wang Z, Zhu Z, Shi N, Xiao D, Yuan L, Shen H, Huang L, Li B. An insular cortical circuit required for itch sensation and aversion. Curr Biol 2024; 34:1453-1468.e6. [PMID: 38484733 DOI: 10.1016/j.cub.2024.02.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 01/09/2024] [Accepted: 02/23/2024] [Indexed: 04/11/2024]
Abstract
Itch encompasses both sensory and emotional dimensions, with the two dimensions reciprocally exacerbating each other. However, whether a shared neural circuit mechanism governs both dimensions remains elusive. Here, we report that the anterior insular cortex (AIC) is activated by both histamine-dependent and -independent itch stimuli. The activation of AIC elicits aversive emotion and exacerbates pruritogen-induced itch sensation and aversion. Mechanistically, AIC excitatory neurons project to the GABAergic neurons in the dorsal bed nucleus of the stria terminalis (dBNST). Manipulating the activity of the AIC → dBNST pathway affects both itch sensation and itch-induced aversion. Our study discovers the shared neural circuit (AIC → dBNST pathway) underlying the itch sensation and aversion, highlights the critical role of the AIC as a central hub for the itch processing, and provides a framework to understand the neural mechanisms underlying the sensation and emotion interaction.
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Affiliation(s)
- Jieyan Zheng
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiao Min Zhang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Wenting Tang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Yonglin Li
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Pei Wang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Jianhua Jin
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Zhengyi Luo
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Shunchang Fang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Shana Yang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Zicheng Wei
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Kexin Song
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Zihan Huang
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Zihao Wang
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Ziyu Zhu
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Naizhen Shi
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Diyun Xiao
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Linyu Yuan
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Hualin Shen
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Lianyan Huang
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Human Microbiome and Chronic Diseases (Sun Yat-sen University), Ministry of Education, Guangzhou 510655, China.
| | - Boxing Li
- Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China; Advanced Medical Technology Center, the First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Human Microbiome and Chronic Diseases (Sun Yat-sen University), Ministry of Education, Guangzhou 510655, China.
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5
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Balzulat A, Zhu WF, Flauaus C, Hernandez‐Olmos V, Heering J, Sethumadhavan S, Dubiel M, Frank A, Menge A, Hebchen M, Metzner K, Lu R, Lukowski R, Ruth P, Knapp S, Müller S, Steinhilber D, Hänelt I, Stark H, Proschak E, Schmidtko A. Discovery of a Small Molecule Activator of Slack (Kcnt1) Potassium Channels That Significantly Reduces Scratching in Mouse Models of Histamine-Independent and Chronic Itch. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2307237. [PMID: 38350720 PMCID: PMC11022729 DOI: 10.1002/advs.202307237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/15/2024] [Indexed: 02/15/2024]
Abstract
Various disorders are accompanied by histamine-independent itching, which is often resistant to the currently available therapies. Here, it is reported that the pharmacological activation of Slack (Kcnt1, KNa1.1), a potassium channel highly expressed in itch-sensitive sensory neurons, has therapeutic potential for the treatment of itching. Based on the Slack-activating antipsychotic drug, loxapine, a series of new derivatives with improved pharmacodynamic and pharmacokinetic profiles is designed that enables to validate Slack as a pharmacological target in vivo. One of these new Slack activators, compound 6, exhibits negligible dopamine D2 and D3 receptor binding, unlike loxapine. Notably, compound 6 displays potent on-target antipruritic activity in multiple mouse models of acute histamine-independent and chronic itch without motor side effects. These properties make compound 6 a lead molecule for the development of new antipruritic therapies targeting Slack.
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Affiliation(s)
- Annika Balzulat
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - W. Felix Zhu
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Cathrin Flauaus
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Victor Hernandez‐Olmos
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMPTheodor‐Stern‐Kai 760596Frankfurt am MainGermany
| | - Jan Heering
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMPTheodor‐Stern‐Kai 760596Frankfurt am MainGermany
| | - Sunesh Sethumadhavan
- Institute of BiochemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Mariam Dubiel
- Institute of Pharmaceutical and Medicinal ChemistryHeinrich Heine University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Annika Frank
- Institute of Pharmaceutical and Medicinal ChemistryHeinrich Heine University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Amelie Menge
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Structural Genomics Consortium (SGC)Buchmann Institute for Molecular Life SciencesGoethe University FrankfurtMax‐von‐Laue‐Str. 1560438Frankfurt am MainGermany
| | - Maureen Hebchen
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Katharina Metzner
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Ruirui Lu
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Robert Lukowski
- Department of PharmacologyToxicology and Clinical PharmacyInstitute of Pharmacy University of TübingenAuf der Morgenstelle 872076TübingenGermany
| | - Peter Ruth
- Department of PharmacologyToxicology and Clinical PharmacyInstitute of Pharmacy University of TübingenAuf der Morgenstelle 872076TübingenGermany
| | - Stefan Knapp
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Structural Genomics Consortium (SGC)Buchmann Institute for Molecular Life SciencesGoethe University FrankfurtMax‐von‐Laue‐Str. 1560438Frankfurt am MainGermany
| | - Susanne Müller
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Structural Genomics Consortium (SGC)Buchmann Institute for Molecular Life SciencesGoethe University FrankfurtMax‐von‐Laue‐Str. 1560438Frankfurt am MainGermany
| | - Dieter Steinhilber
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMPTheodor‐Stern‐Kai 760596Frankfurt am MainGermany
| | - Inga Hänelt
- Institute of BiochemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
| | - Holger Stark
- Institute of Pharmaceutical and Medicinal ChemistryHeinrich Heine University DüsseldorfUniversitätsstr. 140225DüsseldorfGermany
| | - Ewgenij Proschak
- Institute of Pharmaceutical ChemistryGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMPTheodor‐Stern‐Kai 760596Frankfurt am MainGermany
| | - Achim Schmidtko
- Institute of Pharmacology and Clinical PharmacyGoethe University FrankfurtMax‐von‐Laue‐Str. 960438Frankfurt am MainGermany
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6
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van Gool R, Far A, Drenthen GS, Jansen JFA, Goijen CP, Backes WH, Linden DEJ, Merkies ISJ, Faber CG, Upadhyay J, Hoeijmakers JGJ. Peripheral Pain Captured Centrally: Altered Brain Morphology on MRI in Small Fiber Neuropathy Patients With and Without an SCN9A Gene Variant. THE JOURNAL OF PAIN 2024; 25:730-741. [PMID: 37921732 DOI: 10.1016/j.jpain.2023.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/05/2023] [Accepted: 10/03/2023] [Indexed: 11/04/2023]
Abstract
The current study aims to characterize brain morphology of pain as reported by small fiber neuropathy (SFN) patients with or without a gain-of-function variant involving the SCN9A gene and compare these with findings in healthy controls without pain. The Neuropathic Pain Scale was used in patients with idiopathic SFN (N = 20) and SCN9A-associated SFN (N = 12) to capture pain phenotype. T1-weighted, structural magnetic resonance imaging (MRI) data were collected in patients and healthy controls (N = 21) to 1) compare cortical thickness and subcortical volumes and 2) quantify the association between severity, quality, and duration of pain with morphological properties. SCN9A-associated SFN patients showed significant (P < .017, Bonferroni corrected) higher cortical thickness in sensorimotor regions, compared to idiopathic SFN patients, while lower cortical thickness was found in more functionally diverse regions (eg, posterior cingulate cortex). SFN patient groups combined demonstrated a significant (Spearman's ρ = .44-.55, P = .005-.049) correlation among itch sensations (Neuropathic Pain Scale-7) and thickness of the left precentral gyrus, and midcingulate cortices. Significant associations were found between thalamic volumes and duration of pain (left: ρ = -.37, P = .043; right: ρ = -.40, P = .025). No associations were found between morphological properties and other pain qualities. In conclusion, in SCN9A-associated SFN, profound morphological alterations anchored within the pain matrix are present. The association between itch sensations of pain and sensorimotor and midcingulate structures provides a novel basis for further examining neurobiological underpinnings of itch in SFN. PERSPECTIVE: Cortical thickness and subcortical volume alterations in SFN patients were found in pain hubs, more profound in SCN9A-associated neuropathy, and correlated with itch and durations of pain. These findings contribute to our understanding of the pathophysiological pathways underlying chronic neuropathic pain and symptoms of itch in SFN.
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Affiliation(s)
- Raquel van Gool
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands
| | - Amir Far
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands; Department of Neurology, Maastricht University Medical Center+, Maastricht, Limburg, The Netherlands
| | - Gerhard S Drenthen
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands; Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, Limburg, The Netherlands
| | - Jacobus F A Jansen
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands; Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, Limburg, The Netherlands; Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, North Brabant, The Netherlands
| | - Celine P Goijen
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands; Department of Neurology, Maastricht University Medical Center+, Maastricht, Limburg, The Netherlands
| | - Walter H Backes
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands; Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, Limburg, The Netherlands
| | - David E J Linden
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands; Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands
| | - Ingemar S J Merkies
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands; Department of Neurology, Maastricht University Medical Center+, Maastricht, Limburg, The Netherlands; Department of Neurology, Curaçao Medical Center, Willemstad, Kingdom of the Netherlands, Curaçao
| | - Catharina G Faber
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands; Department of Neurology, Maastricht University Medical Center+, Maastricht, Limburg, The Netherlands
| | - Jaymin Upadhyay
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, Massachusetts
| | - Janneke G J Hoeijmakers
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Limburg, The Netherlands; Department of Neurology, Maastricht University Medical Center+, Maastricht, Limburg, The Netherlands
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7
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Pei X, Li B, Xu X, Zhang H. Spinal Caspase-6 Contributes to Intrathecal Morphine-induced Acute Itch and Contact Dermatitis-induced Chronic Itch Through Regulating the Phosphorylation of Protein Kinase Mζ in Mice. Neuroscience 2024; 539:21-34. [PMID: 38176610 DOI: 10.1016/j.neuroscience.2023.12.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 12/08/2023] [Accepted: 12/28/2023] [Indexed: 01/06/2024]
Abstract
Patients receiving neuraxial treatment with morphine for pain relief often experience a distressing pruritus. Neuroinflammation-mediated plasticity of sensory synapses in the spinal cord is critical for the development of pain and itch. Caspase-6, as an intracellular cysteine protease, is capable of inducing central nociceptive sensitization through regulating synaptic transmission and plasticity. Given the tight interaction between protein kinase Mζ (PKMζ) and excitatory synaptic plasticity, this pre-clinical study investigates whether caspase-6 contributes to morphine-induced itch and chronic itch via PKMζ. Intrathecal morphine and contact dermatitis were used to cause pruritus in mice. Morphine antinociception, itch-induced scratching behaviors, spinal activity of caspase-6, and phosphorylation of PKMζ and ERK were examined. Caspase-6 inhibitor Z-VEID-FMK, exogenous caspase-6 and PKMζ inhibitor ZIP were utilized to reveal the mechanisms and prevention of itch. Herein, we report that morphine induces significant scratching behaviors, which is accompanied by an increase in spinal caspase-6 cleavage and PKMζ phosphorylation (but not expression). Intrathecal injection of Z-VEID-FMK drastically reduces morphine-induced scratch bouts and spinal phosphorylation of PKMζ, without abolishing morphine analgesia. Moreover, intrathecal strategies of ZIP dose-dependently reduce morphine-induced itch-like behaviors. Spinal phosphorylation of ERK following neuraxial morphine is down-regulated by ZIP therapy. Recombinant caspase-6 directly exhibits scratching behaviors and spinal phosphorylation of ERK, which is compensated by PKMζ inhibition. Also, spinal inhibition of caspase-6 and PKMζ reduces the generation and maintenance of dermatitis-induced chronic itch. Together, these findings demonstrate that spinal caspase-6 modulation of PKMζ phosphorylation is important in the development of morphine-induced itch and dermatitis-induced itch in mice.
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Affiliation(s)
- Xuxing Pei
- Department of Anesthesiology and Perioperative Medicine, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China
| | - Bing Li
- Department of Anesthesiology and Perioperative Medicine, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China
| | - Xiaodong Xu
- Department of Anesthesiology and Perioperative Medicine, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China
| | - Hui Zhang
- Department of Anesthesiology and Perioperative Medicine, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China.
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8
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Schwarzenauer M, Rukwied RM, Lampert A, Rolke R, Namer B. Electrical matrix stimulation suppresses acute itch independently of activation of sleeping nociceptors. Eur J Pain 2024; 28:285-296. [PMID: 37715607 DOI: 10.1002/ejp.2177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 07/24/2023] [Accepted: 08/19/2023] [Indexed: 09/17/2023]
Abstract
INTRODUCTION Itch can be reduced by pain. Activation of sleeping nociceptors (CMi) is a crucial mechanism for the peripheral component of intense and long-lasting pain. Thus, activation of CMi might be especially effective in itch reduction. Electrical stimulation using sinusoidal pulses activates CMi with tolerable pain intensity, whereas short rectangular pulses with low intensity do not. In humans, histaminergic itch is mediated by histamine-sensitive CMi, whereas other pruritogens activate polymodal nociceptors (CM). METHODS In a psychophysical approach in a balanced crossover repeated-measures design in healthy volunteers, we activated nociceptors by two different electrical stimulation paradigms via a matrix electrode: 4 Hz sinusoidal pulses that activate C-nociceptors including CMi or 4 Hz rectangular stimuli to activate nociceptors excluding CMi. After 5-min stimulation, itch was induced by either histamine iontophoresis or application of cowhage spicules. Itch ratings were assessed via a numerical rating scale (NRS). RESULTS Electrical 4 Hz sine wave stimulation (0.1 mA) with low pain ratings of 1.5 (NRS; 0-10) induced an axon reflex erythema (3 cm2 ), indicating activation of CMi, whereas rectangular 0.2 ms pulses (average 0.91 mA) with the same pain rating did not. Both electrical stimulation paradigms reduced itch magnitude over time evoked by either histamine or cowhage to a similar extent. Peak maximum itch evoked by histamine was reduced by both stimulation paradigms, but not cowhage maximum itch. DISCUSSION Since electrical stimulation with the rectangular pulse paradigm reduces itch to a similar extent as the sine wave stimulation paradigm, the input of CMi is not necessarily required for itch suppression. The input of A-fibres and polymodal nociceptors, similarly, as also achieved by scratching, seems to be sufficient for both forms of chemically evoked itch. SIGNIFICANCE Since activation of CMi does not provide additional benefit for itch suppression, spinal pain pathways transmitted via CM versus CMi have differential effects on itch-processing circuits. This is important knowledge for using electrical matrix stimulation as itch suppressor since activation of sleeping nociceptors either requires significantly painful stimulation paradigms or specialized stimulation paradigms as sinusoidal pulses. An alternative approach using half-sine wave pulses with low pain intensity activating specifically polymodal nociceptors to suppress itch via matrix electrode stimulation may be considered.
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Affiliation(s)
- M Schwarzenauer
- IZKF Research Group Neuroscience, Medical Faculty RWTH Aachen University, Aachen, Germany
- Department of Palliative Medicine, Medical Faculty RWTH Aachen University, Aachen, Germany
| | - R M Rukwied
- Department of Experimental Pain Research, Mannheim Center for Translation Neuroscience (MCTN), Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
| | - A Lampert
- Department for Neurophysiology, Medical Faculty RWTH Aachen University, Aachen, Germany
| | - R Rolke
- Department of Palliative Medicine, Medical Faculty RWTH Aachen University, Aachen, Germany
| | - B Namer
- IZKF Research Group Neuroscience, Medical Faculty RWTH Aachen University, Aachen, Germany
- Department for Neurophysiology, Medical Faculty RWTH Aachen University, Aachen, Germany
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9
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Zeng K, Jiao ZH, Jiang Q, He R, Zhang Y, Li WG, Xu TL, Chen Y. Genetically Encoded Photocatalysis Enables Spatially Restricted Optochemical Modulation of Neurons in Live Mice. ACS CENTRAL SCIENCE 2024; 10:163-175. [PMID: 38292609 PMCID: PMC10823520 DOI: 10.1021/acscentsci.3c01351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 02/01/2024]
Abstract
Light provides high temporal precision for neuronal modulations. Small molecules are advantageous for neuronal modulation due to their structural diversity, allowing them to suit versatile targets. However, current optochemical methods release uncaged small molecules with uniform concentrations in the irradiation area, which lack spatial specificity as counterpart optogenetic methods from genetic encoding for photosensitive proteins. Photocatalysis provides spatial specificity by generating reactive species in the proximity of photocatalysts. However, current photocatalytic methods use antibody-tagged heavy-metal photocatalysts for spatial specificity, which are unsuitable for neuronal applications. Here, we report a genetically encoded metal-free photocatalysis method for the optochemical modulation of neurons via deboronative hydroxylation. The genetically encoded photocatalysts generate doxorubicin, a mitochondrial uncoupler, and baclofen by uncaging stable organoboronate precursors. The mitochondria, nucleus, membrane, cytosol, and ER-targeted drug delivery are achieved by this method. The distinct signaling pathway dissection in a single projection is enabled by the dual optogenetic and optochemical control of synaptic transmission. The itching signaling pathway is investigated by photocatalytic uncaging under live-mice skin for the first time by visible light irradiation. The cell-type-specific release of baclofen reveals the GABABR activation on NaV1.8-expressing nociceptor terminals instead of pan peripheral sensory neurons for itch alleviation in live mice.
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Affiliation(s)
- Kaixing Zeng
- State
Key Laboratory of Chemical Biology, Shanghai Institute of Organic
Chemistry, University of Chinese Academy
of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 China
- School
of Physical Science and Technology, ShanghaiTech
University, 100 Haike Road, Shanghai 201210, China
| | - Zhi-Han Jiao
- Centre
for Brain Science and Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Qin Jiang
- Centre
for Brain Science and Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Ru He
- State
Key Laboratory of Chemical Biology, Shanghai Institute of Organic
Chemistry, University of Chinese Academy
of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 China
- School
of Physical Science and Technology, ShanghaiTech
University, 100 Haike Road, Shanghai 201210, China
| | - Yixin Zhang
- State
Key Laboratory of Chemical Biology, Shanghai Institute of Organic
Chemistry, University of Chinese Academy
of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 China
| | - Wei-Guang Li
- Centre
for Brain Science and Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
- Department
of Rehabilitation Medicine, Huashan Hospital, Institute for Translational
Brain Research, State Key Laboratory of Medical Neurobiology and Ministry
of Education Frontiers Centre for Brain Science, Fudan University, 131 Dongan Road, Shanghai 200032, China
| | - Tian-Le Xu
- Centre
for Brain Science and Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Yiyun Chen
- State
Key Laboratory of Chemical Biology, Shanghai Institute of Organic
Chemistry, University of Chinese Academy
of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 China
- School
of Physical Science and Technology, ShanghaiTech
University, 100 Haike Road, Shanghai 201210, China
- School
of Chemistry and Material Sciences, Hangzhou Institute for Advanced
Study, University of Chinese Academy of
Sciences, Sub-lane Xiangshan, Hangzhou 310024, China
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10
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Poddar S, Mondal H, Podder I. Aetiology, pathogenesis and management of neuropathic itch: A narrative review with recent updates. Indian J Dermatol Venereol Leprol 2024; 90:5-18. [PMID: 37317726 DOI: 10.25259/ijdvl_846_2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 02/17/2023] [Indexed: 06/16/2023]
Abstract
Neuropathic itch is a relatively common yet under-reported cause of systemic pruritus. It is a debilitating condition often associated with pain, which impairs the patient's quality of life. Although much literature exists about renal and hepatic pruritus, there is a dearth of information and awareness about neuropathic itch. The pathogenesis of neuropathic itch is complex and can result from an insult at any point along the itch pathway, ranging from the peripheral receptors and nerves until the brain. There are several causes of neuropathic itch, many of which do not produce any skin lesions and are thus, often missed. A detailed history and clinical examination are necessary for the diagnosis, while laboratory and radiologic investigations may be needed in select cases. Several therapeutic strategies currently exist involving both non-pharmacological and pharmacological measures, the latter including topical, systemic, and invasive options. Further research is ongoing to clarify its pathogenesis and to design newer targeted therapies with minimal adverse effects. This narrative review highlights the current understanding of this condition, focusing on its causes, pathogenesis, diagnosis, and management, along with newer investigational drugs.
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Affiliation(s)
- Shreya Poddar
- Department of Dermatology, Asansol District Hospital, Asansol, West Bengal, India
| | - Himel Mondal
- Department of Physiology, All India Institute of Medical Sciences (AIIMS), Deoghar, Jharkhand, India
| | - Indrashis Podder
- Department of Dermatology, College of Medicine & Sagore Dutta Hospital, Kolkata, West Bengal, India
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11
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Yao J, Li X, Wu GY, Wu B, Long JH, Wang PJ, Liu SL, Gao J, Sui JF. The Anterior Insula and its Projection to the Prelimbic Cortex are Involved in the Regulation of 5-HT-Induced Itch. Neurosci Bull 2023; 39:1807-1822. [PMID: 37553505 PMCID: PMC10661608 DOI: 10.1007/s12264-023-01093-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 04/12/2023] [Indexed: 08/10/2023] Open
Abstract
Itch is an unpleasant sensation that urges people and animals to scratch. Neuroimaging studies on itch have yielded extensive correlations with diverse cortical and subcortical regions, including the insular lobe. However, the role and functional specificity of the insular cortex (IC) and its subdivisions in itch mediation remains unclear. Here, we demonstrated by immunohistochemistry and fiber photometry tests, that neurons in both the anterior insular cortex (AIC) and the posterior insular cortex (PIC) are activated during acute itch processes. Pharmacogenetic experiments revealed that nonselective inhibition of global AIC neurons, or selective inhibition of the activity of glutaminergic neurons in the AIC, reduced the scratching behaviors induced by intradermal injection of 5-hydroxytryptamine (5-HT), but not those induced by compound 48/80. However, both nonselective inhibition of global PIC neurons and selective inhibition of glutaminergic neurons in the PIC failed to affect the itching-scratching behaviors induced by either 5-HT or compound 48/80. In addition, pharmacogenetic inhibition of AIC glutaminergic neurons effectively blocked itch-associated conditioned place aversion behavior, and inhibition of AIC glutaminergic neurons projecting to the prelimbic cortex significantly suppressed 5-HT-evoked scratching. These findings provide preliminary evidence that the AIC is involved, at least partially via aversive emotion mediation, in the regulation of 5-HT-, but not compound 48/80-induced itch.
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Affiliation(s)
- Juan Yao
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China
| | - Xuan Li
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China
| | - Guang-Yan Wu
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China
| | - Bing Wu
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China
| | - Jun-Hui Long
- Department of Dermatology, The 958th Army Hospital of the People's Liberation Army, Chongqing, 400020, China
| | - Pu-Jun Wang
- Department of Dermatology, The 958th Army Hospital of the People's Liberation Army, Chongqing, 400020, China
| | - Shu-Lei Liu
- Department of Dermatology, The 958th Army Hospital of the People's Liberation Army, Chongqing, 400020, China
| | - Jie Gao
- State Key Laboratory of Trauma, Burns and Combined Injury, Army Medical Centre of the PLA, Institute of Surgery Research, Daping Hospital, Army Medical University, Chongqing, 400042, China.
| | - Jian-Feng Sui
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China.
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China.
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12
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Serafin P, Kleczkowska P. Bombesins: A New Frontier in Hybrid Compound Development. Pharmaceutics 2023; 15:2597. [PMID: 38004575 PMCID: PMC10674911 DOI: 10.3390/pharmaceutics15112597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
Recently, bombesin (BN) and its analogs have attracted much attention as excellent anticancer agents because they interact with specific receptors widely distributed on the surface of various cancer cells. However, their biological properties proceed far beyond this, given a broad spectrum of activity. Bombesin receptor ligands are effective drugs for the treatment of rheumatoid arthritis or gastrointestinal diseases. However, most diseases are complex, and the use of polytherapy may lead to pharmacokinetic and pharmacodynamic drug-drug interactions, resulting in side effects. Therefore, there is a need to develop effective compounds that also contain BN or its analogs, which are combined with other structural entities, thus generating a so-called hybrid drug. Hybrid drugs that contain bombesin pharmacophore(s) may be proposed as a solution to the problem of polytherapy or the lack of an effective cure. Such structures have now demonstrated the desired efficacy, though information on these aforementioned compounds is relatively scarce. Therefore, our paper aims to encourage researchers to focus on bombesins. Herein, we indicate that the hybrid approach should also be firmly applied to bombesins and the BN receptor family. This paper's structure is divided into two main sections demonstrating bombesins and their properties, as well as recent data on bombesin-based hybrid compounds and their potential usefulness in medicine. Overall, it refers to the discovery and synthesis of modified bombesin-based hybrid compounds.
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Affiliation(s)
- Pawel Serafin
- Military Institute of Hygiene and Epidemiology, 01-163 Warsaw, Poland;
| | - Patrycja Kleczkowska
- Military Institute of Hygiene and Epidemiology, 01-163 Warsaw, Poland;
- Maria Sklodowska-Curie, Medical Academy in Warsaw, Solidarnosci 12 Str., 03-411 Warsaw, Poland
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13
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Yang Y, Mou B, Zhang QR, Zhao HX, Zhang JY, Yun X, Xiong MT, Liu Y, Liu YU, Pan H, Ma CL, Li BM, Peng J. Microglia are involved in regulating histamine-dependent and non-dependent itch transmissions with distinguished signal pathways. Glia 2023; 71:2541-2558. [PMID: 37392090 DOI: 10.1002/glia.24438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/02/2023]
Abstract
Although itch and pain have many similarities, they are completely different in perceptual experience and behavioral response. In recent years, we have a deep understanding of the neural pathways of itch sensation transmission. However, there are few reports on the role of non-neuronal cells in itch. Microglia are known to play a key role in chronic neuropathic pain and acute inflammatory pain. It is still unknown whether microglia are also involved in regulating the transmission of itch sensation. In the present study, we used several kinds of transgenic mice to specifically deplete CX3CR1+ microglia and peripheral macrophages together (whole depletion), or selectively deplete microglia alone (central depletion). We observed that the acute itch responses to histamine, compound 48/80 and chloroquine were all significantly reduced in mice with either whole or central depletion. Spinal c-fos mRNA assay and further studies revealed that histamine and compound 48/80, but not chloroquine elicited primary itch signal transmission from DRG to spinal Npr1- and somatostatin-positive neurons relied on microglial CX3CL1-CX3CR1 pathway. Our results suggested that microglia were involved in multiple types of acute chemical itch transmission, while the underlying mechanisms for histamine-dependent and non-dependent itch transmission were different that the former required the CX3CL1-CX3CR1 signal pathway.
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Affiliation(s)
- Yuxiu Yang
- School of Basic Medical Sciences, Nanchang University, Nanchang, China
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Bin Mou
- School of Basic Medical Sciences, Nanchang University, Nanchang, China
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Qi-Ruo Zhang
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Hong-Xue Zhao
- School of Basic Medical Sciences, Nanchang University, Nanchang, China
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Jian-Yun Zhang
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Xiao Yun
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Ming-Tao Xiong
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Ying Liu
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Yong U Liu
- Laboratory for Neuroimmunology in Health and Disease, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, China
| | - Haili Pan
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Chao-Lin Ma
- Institute of Life Science, Nanchang University, Nanchang, China
| | - Bao-Ming Li
- Institute of Life Science, Nanchang University, Nanchang, China
- Department of Physiology and Institute of Brain Science, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, China
| | - Jiyun Peng
- School of Basic Medical Sciences, Nanchang University, Nanchang, China
- Institute of Life Science, Nanchang University, Nanchang, China
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14
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Chen WZ, Shen TY, Wang M, Yuan L, Wang LH, Ding WQ, Shi XX, Wang XF, Bo BS, Liang ZF, Sun YG. An atlas of itch-associated neural dynamics in the mouse brain. Cell Rep 2023; 42:113304. [PMID: 37862165 DOI: 10.1016/j.celrep.2023.113304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 08/07/2023] [Accepted: 10/04/2023] [Indexed: 10/22/2023] Open
Abstract
The itch-scratching cycle is mediated by neural dynamics in the brain. However, our understanding of the neural dynamics during this cycle remains limited. In this study, we examine the neural dynamics of 126 mouse brain areas by measuring the calcium signal using fiber photometry. We present numerous response patterns in the mouse brain during the itch-scratching cycle. Interestingly, we find that a group of brain areas exhibit activation only at the end of histamine-induced scratching behavior. Additionally, several brain areas exhibit transient activation at the onset of scratching induced by chloroquine. Both histamine- and chloroquine-induced itch evoke diverse response patterns across the mouse brain. In summary, our study provides a comprehensive dataset for the diverse activity pattern of mouse brain during the itch-scratching cycle, paving the way for further exploration into the neural mechanisms underlying the itch-scratching cycle.
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Affiliation(s)
- Wen-Zhen Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Ting-Yu Shen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Meng Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Lin Yuan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; Department of Orthopaedic Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Lin-Han Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Wen-Qun Ding
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Xiao-Xue Shi
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Xiao-Fei Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Bin-Shi Bo
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Zhi-Feng Liang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Yan-Gang Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
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15
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Mogilski S, Kubacka M, Świerczek A, Wyska E, Szczepańska K, Sapa J, Kieć-Kononowicz K, Łażewska D. Efficacy of the Multi-Target Compound E153 in Relieving Pain and Pruritus of Different Origins. Pharmaceuticals (Basel) 2023; 16:1481. [PMID: 37895952 PMCID: PMC10609854 DOI: 10.3390/ph16101481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/04/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Itch and pain are closely related but distinct sensations that share largely overlapping mediators and receptors. We hypothesized that the novel, multi-target compound E153 has the potential to attenuate pain and pruritus of different origins. After the evaluation of sigma receptor affinity and pharmacokinetic studies, we tested the compound using different procedures and models of pain and pruritus. Additionally, we used pharmacological tools, such as PRE-084, RAMH, JNJ 5207852, and S1RA, to precisely determine the role of histamine H3 and sigma 1 receptors in the analgesic and antipruritic effects of the compound. In vitro studies revealed that the test compound had potent affinity for sigma 1 and sigma 2 receptors, moderate affinity for opioid kappa receptors, and no affinity for delta or μ receptors. Pharmacokinetic studies showed that after intraperitoneal administration, the compound was present at high concentrations in both the peripheral tissues and the central nervous system. The blood-brain barrier-penetrating properties indicate its ability to act centrally at the levels of the brain and spinal cord. Furthermore, the test compound attenuated different types of pain, including acute, inflammatory, and neuropathic. It also showed a broad spectrum of antipruritic activity, attenuating histamine-dependent and histamine-independent itching. Finally, we proved that antagonism of both sigma 1 and histamine H3 receptors is involved in the analgesic activity of the compound, while the antipruritic effect to a greater extent depends on sigma 1 antagonism.
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Affiliation(s)
- Szczepan Mogilski
- Department of Pharmacodynamics, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (M.K.); (J.S.)
| | - Monika Kubacka
- Department of Pharmacodynamics, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (M.K.); (J.S.)
| | - Artur Świerczek
- Department of Pharmacokinetics and Physical Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (A.Ś.); (E.W.)
| | - Elżbieta Wyska
- Department of Pharmacokinetics and Physical Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (A.Ś.); (E.W.)
| | - Katarzyna Szczepańska
- Department of Technology and Biotechnology of Drugs, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (K.S.); (K.K.-K.); (D.Ł.)
- Department of Medicinal Chemistry, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Jacek Sapa
- Department of Pharmacodynamics, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (M.K.); (J.S.)
| | - Katarzyna Kieć-Kononowicz
- Department of Technology and Biotechnology of Drugs, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (K.S.); (K.K.-K.); (D.Ł.)
| | - Dorota Łażewska
- Department of Technology and Biotechnology of Drugs, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland; (K.S.); (K.K.-K.); (D.Ł.)
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Mahmoud O, Oladipo O, Mahmoud RH, Yosipovitch G. Itch: from the skin to the brain - peripheral and central neural sensitization in chronic itch. Front Mol Neurosci 2023; 16:1272230. [PMID: 37849619 PMCID: PMC10577434 DOI: 10.3389/fnmol.2023.1272230] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 09/05/2023] [Indexed: 10/19/2023] Open
Abstract
Similar to chronic pain, chronic itch is frequently linked to neural sensitization, a phenomenon wherein the nervous system becomes hypersensitive to stimuli. This process of neural sensitization of chronic itch is orchestrated by various signaling pathways and mediators in both the peripheral and central nervous systems. At the level of the peripheral nervous system, inflammation and neuroimmune interactions induce plastic changes to peripheral nerve fibers, thereby amplifying the transmission of itch signaling. Neural sensitization in the central nervous system occurs at both the spinal cord and brain levels. At the level of the spinal cord, it involves hyperactivity of itch-activating spinal pathways, dysfunction of spinal inhibitory circuits, and attenuation of descending supraspinal inhibitory pathways. In the brain, neural sensitization manifests as structural and functional changes to itch-associated brain areas and networks. Currently, we have a diverse array of neuroimmune-modulating therapies targeting itch neural sensitization mechanisms to help with providing relief to patients with chronic itch. Itch research is a dynamic and continually evolving field, and as we grow in our understanding of chronic itch mechanisms, so will our therapeutic toolbox. Further studies exploring the peripheral and central neural sensitization mechanisms in the context of chronic itch are needed.
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Affiliation(s)
| | | | | | - Gil Yosipovitch
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, Miami Itch Center, University of Miami Miller School of Medicine, Miami, FL, United States
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17
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ZHAO Y, YAN X, JIANG S, LIU Y, DONG C, CHI H, MAO C. Zhenxin Anshen formula ameliorates atopic der-matitis-like skin dysfunction in mice and regulation of transient receptor potential vanilloid 1 and transient receptor potential ankyrin 1 in Neural pathways. J TRADIT CHIN MED 2023; 43:887-896. [PMID: 37679976 PMCID: PMC10465825 DOI: 10.19852/j.cnki.jtcm.20230802.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 06/15/2022] [Indexed: 09/09/2023]
Abstract
OBJECTIVE To investigate the efficacy of Zhenxin Anshen formula (, ZXAS) on atopic dermatitis (AD) by transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1) signalling pathway in mice and . METHODS AD-like lesions were induced by 1-chloro-2,4-dinitrobenzene (DNCB) to the shaved dorsal skin of BALB/c mice. BALB/c mice were divided into five groups: normal control, model control, cetirizine, low-, medium-, and high-dose of ZXAS. After ZXAS in-tervention, the skin lesions and blood samples were collected for hematoxylin and eosin-stained and measuring the concentrations of inflammatory cytokines. Immun-oglobulin E (IgE), interleukin (IL)-4, IL-5, IL-13, and thymic stromal lymphopoietin (TSLP) were de-tected by Enzyme-linked immunosorbent assay (ELISA). The spinal cords were collected for measuring the expression of gastrin-releasing peptide receptor (GRPR), TRPV1, and TRPA1 by using immunohistochemistry, western blotting, and quantitative real-time polymerase chain reaction (qRT-PCR) analyses. In addition, 3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, ELISA, and Western blotting were conducted for analysis of primary dorsal root ganglia (DRG) neurons . RESULTS ZXAS treatment improved DNCB-induced AD-like lesions through reducing dermatitis score, number of scratching and epidermal thickness, accompanied by the de-creased IgE and Th2 inflammatory cytokines. ZXAS also supressed the mRNA and protein expression of GRPR, TRPV1, and TRPA1 in the spinal cord. The medicated sera of ZXAS decreased capsaicin-induced Ca influx and downregulated the expression of TRPV1, TRPA1, and phospholipase C in DRG neurons. CONCLUSIONS The therapeutic effect of ZXAS on AD may be related to the regulation of TRPV1 and TRPA1 and inhibition of Ca2+ signals in neurons.
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Affiliation(s)
- Yiding ZHAO
- 1 Department of Dermatology, Shaanxi Provincial Hospital of traditional Chinese Medicine, Xi’an 710003, China
| | - Xiaoning YAN
- 1 Department of Dermatology, Shaanxi Provincial Hospital of traditional Chinese Medicine, Xi’an 710003, China
| | - Shanshan JIANG
- 1 Department of Dermatology, Shaanxi Provincial Hospital of traditional Chinese Medicine, Xi’an 710003, China
| | - Yong LIU
- 1 Department of Dermatology, Shaanxi Provincial Hospital of traditional Chinese Medicine, Xi’an 710003, China
| | - Chun DONG
- 1 Department of Dermatology, Shaanxi Provincial Hospital of traditional Chinese Medicine, Xi’an 710003, China
| | - Huiyan CHI
- 2 Department of Dermatology, Xiyuan Hospital China Academy of Chinese Medical Sciences, Beijing 100193, China
| | - Chaoyi MAO
- 3 Department of Education Management, China Academy of Chinese Medical Sciences, Beijing 100700, China
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18
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Bohic M, Upadhyay A, Eisdorfer JT, Keating J, Simon RC, Briones BA, Azadegan C, Nacht HD, Oputa O, Martinez AM, Bethell BN, Gradwell MA, Romanienko P, Ramer MS, Stuber GD, Abraira VE. A new Hoxb8FlpO mouse line for intersectional approaches to dissect developmentally defined adult sensorimotor circuits. Front Mol Neurosci 2023; 16:1176823. [PMID: 37603775 PMCID: PMC10437123 DOI: 10.3389/fnmol.2023.1176823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 07/04/2023] [Indexed: 08/23/2023] Open
Abstract
Improvements in the speed and cost of expression profiling of neuronal tissues offer an unprecedented opportunity to define ever finer subgroups of neurons for functional studies. In the spinal cord, single cell RNA sequencing studies support decades of work on spinal cord lineage studies, offering a unique opportunity to probe adult function based on developmental lineage. While Cre/Flp recombinase intersectional strategies remain a powerful tool to manipulate spinal neurons, the field lacks genetic tools and strategies to restrict manipulations to the adult mouse spinal cord at the speed at which new tools develop. This study establishes a new workflow for intersectional mouse-viral strategies to dissect adult spinal function based on developmental lineages in a modular fashion. To restrict manipulations to the spinal cord, we generate a brain-sparing Hoxb8FlpO mouse line restricting Flp recombinase expression to caudal tissue. Recapitulating endogenous Hoxb8 gene expression, Flp-dependent reporter expression is present in the caudal embryo starting day 9.5. This expression restricts Flp activity in the adult to the caudal brainstem and below. Hoxb8FlpO heterozygous and homozygous mice do not develop any of the sensory or locomotor phenotypes evident in Hoxb8 heterozygous or mutant animals, suggesting normal developmental function of the Hoxb8 gene and protein in Hoxb8FlpO mice. Compared to the variability of brain recombination in available caudal Cre and Flp lines, Hoxb8FlpO activity is not present in the brain above the caudal brainstem, independent of mouse genetic background. Lastly, we combine the Hoxb8FlpO mouse line with dorsal horn developmental lineage Cre mouse lines to express GFP in developmentally determined dorsal horn populations. Using GFP-dependent Cre recombinase viruses and Cre recombinase-dependent inhibitory chemogenetics, we target developmentally defined lineages in the adult. We show how developmental knock-out versus transient adult silencing of the same ROR𝛃 lineage neurons affects adult sensorimotor behavior. In summary, this new mouse line and viral approach provides a blueprint to dissect adult somatosensory circuit function using Cre/Flp genetic tools to target spinal cord interneurons based on genetic lineage.
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Affiliation(s)
- Manon Bohic
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Aman Upadhyay
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- Neuroscience PhD Program at Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, United States
| | - Jaclyn T. Eisdorfer
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Jessica Keating
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- School of Medicine, Oregon Health and Science University, Portland, OR, United States
- M.D./PhD Program in Neuroscience, School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Rhiana C. Simon
- Center for the Neurobiology of Addiction, Pain, and Emotion, Department of Anesthesiology and Pain Medicine, Department of Pharmacology, University of Washington, Seattle, WA, United States
| | - Brandy A. Briones
- Center for the Neurobiology of Addiction, Pain, and Emotion, Department of Anesthesiology and Pain Medicine, Department of Pharmacology, University of Washington, Seattle, WA, United States
| | - Chloe Azadegan
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Hannah D. Nacht
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Olisemeka Oputa
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Alana M. Martinez
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Bridget N. Bethell
- International Collaboration on Repair Discoveries and Department of Zoology, The University of British Columbia, Vancouver, BC, Canada
| | - Mark A. Gradwell
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Peter Romanienko
- Genome Editing Shared Resource, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, United States
| | - Matt S. Ramer
- International Collaboration on Repair Discoveries and Department of Zoology, The University of British Columbia, Vancouver, BC, Canada
| | - Garret D. Stuber
- Center for the Neurobiology of Addiction, Pain, and Emotion, Department of Anesthesiology and Pain Medicine, Department of Pharmacology, University of Washington, Seattle, WA, United States
| | - Victoria E. Abraira
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
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19
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Boyle KA, Polgar E, Gutierrez-Mecinas M, Dickie AC, Cooper AH, Bell AM, Jumolea E, Casas-Benito A, Watanabe M, Hughes DI, Weir GA, Riddell JS, Todd AJ. Neuropeptide Y-expressing dorsal horn inhibitory interneurons gate spinal pain and itch signalling. eLife 2023; 12:RP86633. [PMID: 37490401 PMCID: PMC10392120 DOI: 10.7554/elife.86633] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023] Open
Abstract
Somatosensory information is processed by a complex network of interneurons in the spinal dorsal horn. It has been reported that inhibitory interneurons that express neuropeptide Y (NPY), either permanently or during development, suppress mechanical itch, with no effect on pain. Here, we investigate the role of interneurons that continue to express NPY (NPY-INs) in the adult mouse spinal cord. We find that chemogenetic activation of NPY-INs reduces behaviours associated with acute pain and pruritogen-evoked itch, whereas silencing them causes exaggerated itch responses that depend on cells expressing the gastrin-releasing peptide receptor. As predicted by our previous studies, silencing of another population of inhibitory interneurons (those expressing dynorphin) also increases itch, but to a lesser extent. Importantly, NPY-IN activation also reduces behavioural signs of inflammatory and neuropathic pain. These results demonstrate that NPY-INs gate pain and itch transmission at the spinal level, and therefore represent a potential treatment target for pathological pain and itch.
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Affiliation(s)
- Kieran A Boyle
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Erika Polgar
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Maria Gutierrez-Mecinas
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Allen C Dickie
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Andrew H Cooper
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Andrew M Bell
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Evelline Jumolea
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Adrian Casas-Benito
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo, Japan
| | - David I Hughes
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Gregory A Weir
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - John S Riddell
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Andrew J Todd
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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20
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Misery L, Pierre O, Le Gall-Ianotto C, Lebonvallet N, Chernyshov PV, Le Garrec R, Talagas M. Basic mechanisms of itch. J Allergy Clin Immunol 2023; 152:11-23. [PMID: 37201903 DOI: 10.1016/j.jaci.2023.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 05/02/2023] [Accepted: 05/11/2023] [Indexed: 05/20/2023]
Abstract
Pruritus (or itch) is an unpleasant sensation leading to a desire to scratch. In the epidermis, there are selective C or Aδ epidermal nerve endings that are pruriceptors. At their other ends, peripheral neurons form synapses with spinal neurons and interneurons. Many areas in the central nervous system are involved in itch processing. Although itch does not occur solely because of parasitic, allergic, or immunologic diseases, it is usually the consequence of neuroimmune interactions. Histamine is involved in a minority of itchy conditions, and many other mediators play a role: cytokines (eg, IL-4, IL-13, IL-31, IL-33, and thymic stromal lymphopoietin), neurotransmitters (eg, substance P, calcitonin gene-related peptide, vasoactive intestinal peptide, neuropeptide Y, NBNP, endothelin 1, and gastrin-releasing peptide), and neurotrophins (eg, nerve growth factor and brain-derived neurotrophic factor). Moreover, ion channels such as voltage-gated sodium channels, transient receptor potential vanilloid 1, transient receptor ankyrin, and transient receptor potential cation channel subfamily M (melastatin) member 8 play a crucial role. The main markers of nonhistaminergic pruriceptors are PAR-2 and MrgprX2. A notable phenomenon is the sensitization to pruritus, in which regardless of the initial cause of pruritus, there is an increased responsiveness of peripheral and central pruriceptive neurons to their normal or subthreshold afferent input in the context of chronic itch.
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Affiliation(s)
- Laurent Misery
- Laboratoire Interactions Neurones-Keratinocytes (LINK), University of Brest, Brest, France; Department of Dermatology and Venereology, University Hospital of Brest, Brest, France.
| | - Ophélie Pierre
- Laboratoire Interactions Neurones-Keratinocytes (LINK), University of Brest, Brest, France
| | - Christelle Le Gall-Ianotto
- Laboratoire Interactions Neurones-Keratinocytes (LINK), University of Brest, Brest, France; Department of Dermatology and Venereology, University Hospital of Brest, Brest, France
| | - Nicolas Lebonvallet
- Laboratoire Interactions Neurones-Keratinocytes (LINK), University of Brest, Brest, France
| | - Pavel V Chernyshov
- Department of Dermatology and Venereology, National Medical University, Kiev, Ukraine
| | - Raphaële Le Garrec
- Laboratoire Interactions Neurones-Keratinocytes (LINK), University of Brest, Brest, France
| | - Matthieu Talagas
- Laboratoire Interactions Neurones-Keratinocytes (LINK), University of Brest, Brest, France; Department of Dermatology and Venereology, University Hospital of Brest, Brest, France
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21
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Chen R, Xu X, Wang XY, Jia WB, Zhao DS, Liu N, Pang Z, Liu XQ, Zhang Y. The lateral habenula nucleus regulates pruritic sensation and emotion. Mol Brain 2023; 16:54. [PMID: 37370111 DOI: 10.1186/s13041-023-01045-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
Itch is a complex aversive sensory and emotional experience. As a most upsetting symptom in many dermatological and systemic diseases, it lacks efficient treatments. The lateral habenula nucleus (LHb) encodes negative emotions in the epithalamus and has been implicated in pain and analgesia. Nevertheless, the role of the lateral habenula nucleus in the pruritic sensation and emotion remains elusive. Here we defined the crucial role of glutamatergic neurons within the lateral habenula nucleus (GluLHb) in itch modulation in mice. We established histamine-dependent and histamine-independent models of acute pruritus, as well as the acetone-ether-water (AEW) model of chronic pruritus. We first assessed the effects of pruritogen injection on neural activation in both medial and lateral divisions of LHb in vitro. We then demonstrated that the population activity of GluLHb neurons was increased during the acute itch and chronic itch-induced scratching behaviors in vivo. In addition, electrophysiological data showed that the excitability of GluLHb neurons was enhanced by chronic itch. Chemogenetic suppression of GluLHb neurons disrupted both acute and chronic itch-evoked scratching behaviors. Furthermore, itch-induced conditioned place aversion (CPA) was abolished by GluLHb neuronal inhibition. Finally, we dissected the LHb upstream brain regions. Together, these findings reveal the involvement of LHb in processing both the sensational and emotional components of pruritus and may shed new insights into itch therapy.
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Affiliation(s)
- Rui Chen
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Xiang Xu
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Xin-Yue Wang
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Wen-Bin Jia
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - De-Shan Zhao
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Na Liu
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Zhen Pang
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Xiao-Qing Liu
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Yan Zhang
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China.
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22
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Metz M, Elberskirch M, Reuter C, Liedtke L, Maurer M. Efficacy of Concentrated Heat for Treatment of Insect Bites: A Real-world Study. Acta Derm Venereol 2023; 103:adv11592. [PMID: 37358395 PMCID: PMC10309056 DOI: 10.2340/actadv.v103.11592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/17/2023] [Indexed: 06/27/2023] Open
Abstract
Insect bites that cause itch, pain and swelling are very common. The use of concentrated heat for relief of these symptoms may be a promising approach; however, the scientific evidence for efficacy of hyperthermia treatment is sparse. We report here the results of a large real-world study using a randomized control group to assess the efficacy of hyperthermia on insect bites in real-world conditions, specifically considering mosquito bites as the most common type. The study was conducted in a decentralized manner via a smartphone-controlled medical device, heat it®, for treatment of insect bites and stings through application of heat. The application that controls the device was accompanied by additional questionnaires, that collected data related to insect bites, such as itch and pain intensity. Analysis of data from over 12,000 collected treated insect bites, generated by approximately 1,750 participants (42% female, 39 ± 13 years) showed significant inhibition of itch and pain for all investigated insect species (mosquitoes, horseflies, bees and wasps). Mosquito bite-induced itch was reduced by 57% within the first minute and by 81% 5-10 min after treatment, and the overall reduction in itch and pain was more pronounced than in the control group. In conclusion, the results indicate that local application of heat relieves symptoms of insect bites.
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Affiliation(s)
- Martin Metz
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, Berlin, Germany.
| | | | | | | | - Marcus Maurer
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, Berlin, Germany
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23
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Lee C, Oh J, Lee JH, Kaang BK, Ko HG. Loosely synchronized activation of anterior cingulate cortical neurons for scratching response during histamine-induced itch. Mol Brain 2023; 16:51. [PMID: 37312130 DOI: 10.1186/s13041-023-01037-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/24/2023] [Indexed: 06/15/2023] Open
Abstract
Itch is a distinctive sensation that causes a specific affection and scratching reaction. The anterior cingulate cortex (ACC) has been linked to itch sensation in numerous studies; however, its precise function in processing pruritic inputs remains unknown. Distinguishing the precise role of the ACC in itch sensation can be challenging because of its capacity to conduct heterologous neurophysiological activities. Here, we used in vivo calcium imaging to examine how ACC neurons in free-moving mice react to pruritogenic histamine. In particular, we focused on how the activity of the ACC neurons varied before and after the scratching response. We discovered that although the change in neuronal activity was not synchronized with the scratching reaction, the overall activity of itch-responsive neurons promptly decreased after the scratching response. These findings suggest that the ACC does not directly elicit the feeling of itchiness.
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Affiliation(s)
- Chiwoo Lee
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Jihae Oh
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Jae-Hyung Lee
- Department of Oral Microbiology, College of Dentistry, Kyung Hee University, Seoul, 02447, South Korea
| | - Bong-Kiun Kaang
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
| | - Hyoung-Gon Ko
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 2177 Dalgubeol-daero, Daegu, 41940, South Korea.
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24
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Cronin SJF, Tejada MA, Song R, Laval K, Cikes D, Ji M, Brai A, Stadlmann J, Novatchikova M, Perlot T, Ali OH, Botta L, Decker T, Lazovic J, Hagelkruys A, Enquist L, Rao S, Koyuncu OO, Penninger JM. Pseudorabies virus hijacks DDX3X, initiating an addictive "mad itch" and immune suppression, to facilitate viral spread. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.09.539956. [PMID: 37214906 PMCID: PMC10197578 DOI: 10.1101/2023.05.09.539956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Infections with defined Herpesviruses, such as Pseudorabies virus (PRV) and Varicella zoster virus (VZV) can cause neuropathic itch, referred to as "mad itch" in multiple species. The underlying mechanisms involved in neuropathic "mad itch" are poorly understood. Here, we show that PRV infections hijack the RNA helicase DDX3X in sensory neurons to facilitate anterograde transport of the virus along axons. PRV induces re-localization of DDX3X from the cell body to the axons which ultimately leads to death of the infected sensory neurons. Inducible genetic ablation of Ddx3x in sensory neurons results in neuronal death and "mad itch" in mice. This neuropathic "mad itch" is propagated through activation of the opioid system making the animals "addicted to itch". Moreover, we show that PRV co-opts and diverts T cell development in the thymus via a sensory neuron-IL-6-hypothalamus-corticosterone stress pathway. Our data reveal how PRV, through regulation of DDX3X in sensory neurons, travels along axons and triggers neuropathic itch and immune deviations to initiate pathophysiological programs which facilitate its spread to enhance infectivity.
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Affiliation(s)
- Shane J F Cronin
- Institute of Molecular Biotechnology Austria (IMBA), Dr. Bohrgasse 3, A-1030 Vienna, Austria
| | - Miguel A Tejada
- Institute of Molecular Biotechnology Austria (IMBA), Dr. Bohrgasse 3, A-1030 Vienna, Austria
| | - Ren Song
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Kathlyn Laval
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
- Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Domagoj Cikes
- Institute of Molecular Biotechnology Austria (IMBA), Dr. Bohrgasse 3, A-1030 Vienna, Austria
| | - Ming Ji
- Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Annalaura Brai
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, I-53100 Siena, Italy
| | - Johannes Stadlmann
- Institute of Molecular Biotechnology Austria (IMBA), Dr. Bohrgasse 3, A-1030 Vienna, Austria
| | - Maria Novatchikova
- Institute of Molecular Biotechnology Austria (IMBA), Dr. Bohrgasse 3, A-1030 Vienna, Austria
| | - Thomas Perlot
- Institute of Molecular Biotechnology Austria (IMBA), Dr. Bohrgasse 3, A-1030 Vienna, Austria
| | - Omar Hasan Ali
- Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, Canada
- Institute of Immunobiology, Cantonal Hospital St. Gallen, Rorschacher Strasse 95, 9007 St. Gallen, Switzerland
- Department of Dermatology, University of Zurich, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
| | - Lorenzo Botta
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, I-53100 Siena, Italy
| | - Thomas Decker
- Max F. Perutz Laboratories, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter, Vienna, Austria
| | - Jelena Lazovic
- Institute of Molecular Biotechnology Austria (IMBA), Dr. Bohrgasse 3, A-1030 Vienna, Austria
| | - Astrid Hagelkruys
- Institute of Molecular Biotechnology Austria (IMBA), Dr. Bohrgasse 3, A-1030 Vienna, Austria
| | - Lynn Enquist
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Shuan Rao
- Department of Thoracic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Orkide O Koyuncu
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, Irvine, CA 92697-4025, USA
| | - Josef M Penninger
- Institute of Molecular Biotechnology Austria (IMBA), Dr. Bohrgasse 3, A-1030 Vienna, Austria
- Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, Canada
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25
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Li JN, Wu XM, Zhao LJ, Sun HX, Hong J, Wu FL, Chen SH, Chen T, Li H, Dong YL, Li YQ. Central medial thalamic nucleus dynamically participates in acute itch sensation and chronic itch-induced anxiety-like behavior in male mice. Nat Commun 2023; 14:2539. [PMID: 37137899 PMCID: PMC10156671 DOI: 10.1038/s41467-023-38264-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/20/2023] [Indexed: 05/05/2023] Open
Abstract
Itch is an annoying sensation consisting of both sensory and emotional components. It is known to involve the parabrachial nucleus (PBN), but the following transmission nodes remain elusive. The present study identified that the PBN-central medial thalamic nucleus (CM)-medial prefrontal cortex (mPFC) pathway is essential for itch signal transmission at the supraspinal level in male mice. Chemogenetic inhibition of the CM-mPFC pathway attenuates scratching behavior or chronic itch-related affective responses. CM input to mPFC pyramidal neurons is enhanced in acute and chronic itch models. Specifically chronic itch stimuli also alter mPFC interneuron involvement, resulting in enhanced feedforward inhibition and a distorted excitatory/inhibitory balance in mPFC pyramidal neurons. The present work underscores CM as a transmit node of the itch signal in the thalamus, which is dynamically engaged in both the sensory and affective dimensions of itch with different stimulus salience.
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Affiliation(s)
- Jia-Ni Li
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
| | - Xue-Mei Wu
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
- Department of Human Anatomy, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, China
| | - Liu-Jie Zhao
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China
| | - Han-Xue Sun
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
- Department of Human Anatomy, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, 350122, China
| | - Jie Hong
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
- Department of Human Anatomy, Baotou Medical College Inner Mongolia University of Science and Technology, Baotou, 014040, China
| | - Feng-Ling Wu
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China
| | - Si-Hai Chen
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China
| | - Tao Chen
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
| | - Hui Li
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
| | - Yu-Lin Dong
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China.
| | - Yun-Qing Li
- Department of Anatomy, Histology and Embryology, K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China.
- Department of Human Anatomy, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, China.
- Department of Anatomy, Basic Medical College, Zhengzhou University, Zhengzhou, 450001, China.
- Department of Human Anatomy, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, 350122, China.
- Department of Human Anatomy, Baotou Medical College Inner Mongolia University of Science and Technology, Baotou, 014040, China.
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26
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Li N, Wang C, Zhao Y, Wang Y, Gao T, Yu Y, Wang G, Zhang L. STING controls opioid-induced itch and chronic itch via spinal tank-binding kinase 1-dependent type I interferon response in mice. J Neuroinflammation 2023; 20:101. [PMID: 37122031 PMCID: PMC10150483 DOI: 10.1186/s12974-023-02783-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 04/20/2023] [Indexed: 05/02/2023] Open
Abstract
BACKGROUND Patients receiving epidural or intrathecal opioids administration for neuraxial analgesia frequently suffer from an irritating itch. STING (stimulator of interferon genes), an innate immune modulator, is strongly implicated in pain pathogenesis via neuron-immune modulation. Given that pain and itch share some common neurocircuits, we evaluate the therapeutic potential of STING agonists in opioid-induced itch and chronic itch. METHODS Opioids (morphine, fentanyl and sufentanil) were intrathecally injected to induce acute itch. Chronic itch was induced by dry skin and contact dermatitis. Opioids analgesic effect, itch-induced scratching behavior, spinal expression of STING, phosphorylation of TBK1 (tank-binding kinase 1), IRF3 (interferon regulatory factor-3) and ERK (extracellular signal-regulated kinase), as well as production of IFN-α and IFN-β were examined. STING agonists (DMXAA and ADU-S100), TBK1 inhibitor, recombinant IFN-α and IFN-β elucidated the mechanism and treatment of itch. Whole-brain functional connectivity was evaluated using resting-state fMRI. RESULTS We report the primary expression of STING protein by the spinal dorsal horn neurons. Intraperitoneal injection of DMXAA dose-dependently reduces morphine-induced scratch bouts, without impairing morphine antinociception. Simultaneously, DMXAA alleviates fentanyl- and sufentanil-induced itching-like behavior, and chronic scratching behavior caused by dry skin and contact dermatitis. Furthermore, DMXAA drastically increases spinal phosphorylation of TBK1 and IRF3 following morphine exposure, dry skin and contact dermatitis. DMXAA-induced anti-pruritus effects and spinal productions of IFN-α and IFN-β are compensated by intrathecal delivery of the TBK1 inhibitor. Also, ADU-S100, recombinant IFN-α and IFN-β exhibits remarkable attenuation in scratching behaviors after morphine injection and dermatitis. Recombinant IFN-α inhibits morphine-induced spinal phosphorylation of ERK. Finally, DMXAA prevents dermatitis-induced the increase of cerebral functional connectivity between regions of interests such as primary somatosensory cortex, piriform cortex, retrosplenial cortex, colliculus and ventral thalamus. CONCLUSIONS STING activation confers protection against opioid-induced itch and chronic itch through spinal up-regulation of TBK1-IRF3-type I interferon cascades in mice, suggesting that STING agonists are promising candidates in translational development for pruritus relief.
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Affiliation(s)
- Nan Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
- Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Chunyan Wang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
- Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Yuying Zhao
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
- Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Yigang Wang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
- Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Tianyu Gao
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
- Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Yonghao Yu
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
- Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Guolin Wang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
- Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China
| | - Linlin Zhang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, 300052, China.
- Tianjin Research Institute of Anesthesiology, Tianjin, 300052, China.
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27
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Galor A, Britten-Jones AC, Feng Y, Ferrari G, Goldblum D, Gupta PK, Merayo-Lloves J, Na KS, Naroo SA, Nichols KK, Rocha EM, Tong L, Wang MTM, Craig JP. TFOS Lifestyle: Impact of lifestyle challenges on the ocular surface. Ocul Surf 2023; 28:262-303. [PMID: 37054911 DOI: 10.1016/j.jtos.2023.04.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 04/07/2023] [Indexed: 04/15/2023]
Abstract
Many factors in the domains of mental, physical, and social health have been associated with various ocular surface diseases, with most of the focus centered on aspects of dry eye disease (DED). Regarding mental health factors, several cross-sectional studies have noted associations between depression and anxiety, and medications used to treat these disorders, and DED symptoms. Sleep disorders (both involving quality and quantity of sleep) have also been associated with DED symptoms. Under the domain of physical health, several factors have been linked to meibomian gland abnormalities, including obesity and face mask wear. Cross-sectional studies have also linked chronic pain conditions, specifically migraine, chronic pain syndrome and fibromyalgia, to DED, principally focusing on DED symptoms. A systematic review and meta-analysis reviewed available data and concluded that various chronic pain conditions increased the risk of DED (variably defined), with odds ratios ranging from 1.60 to 2.16. However, heterogeneity was noted, highlighting the need for additional studies examining the impact of chronic pain on DED signs and subtype (evaporative versus aqueous deficient). With respect to societal factors, tobacco use has been most closely linked to tear instability, cocaine to decreased corneal sensitivity, and alcohol to tear film disturbances and DED symptoms.
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Affiliation(s)
- Anat Galor
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA; Surgical Services, Miami Veterans Administration, Miami, FL, USA.
| | - Alexis Ceecee Britten-Jones
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Victoria, Australia
| | - Yun Feng
- Department of Ophthalmology, Peking University Eye Center, Peking University Third Hospital, Beijing, China
| | - Giulio Ferrari
- Cornea and Ocular Surface Unit, Eye Repair Lab, San Raffaele Scientific Institute, Milan, Italy
| | - David Goldblum
- Pallas-Kliniken, Olten, Bern, Zurich, Switzerland; University of Basel, Basel, Switzerland
| | - Preeya K Gupta
- Triangle Eye Consultants, Raleigh, NC, USA; Department of Ophthalmology, Tulane University, New Orleans, LA, USA
| | - Jesus Merayo-Lloves
- Instituto Universitario Fernandez-Vega, Universidad de Oviedo, Principality of Asturias, Spain
| | - Kyung-Sun Na
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Shehzad A Naroo
- College of Health and Life Sciences, Aston University, Birmingham, UK
| | - Kelly K Nichols
- School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Eduardo M Rocha
- Department of Ophthalmology, Othorynolaringology and Head & Neck Surgery, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Louis Tong
- Cornea and External Eye Disease Service, Singapore National Eye Center, Ocular Surface Research Group, Singapore Eye Research Institute, Eye Academic Clinical Program, Duke-National University of Singapore, Singapore
| | - Michael T M Wang
- Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand
| | - Jennifer P Craig
- Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand
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Vander Does A, Ju T, Mohsin N, Chopra D, Yosipovitch G. How to get rid of itching. Pharmacol Ther 2023; 243:108355. [PMID: 36739914 DOI: 10.1016/j.pharmthera.2023.108355] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/01/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023]
Abstract
Itch is an unpleasant sensation arising from a variety of dermatologic, neuropathic, systemic, and psychogenic etiologies. Various itch pathways are implicated according to the underlying etiology. A variety of pruritogens, or itch mediators, as well as receptors have been identified and provide potential therapeutic targets. Recent research has primarily focused on targeting inflammatory cytokines and Janus kinase signaling, protease-activated receptors, substance P and neurokinin, transient receptor potential-vanilloid ion channels, Mas-related G-protein-coupled receptors (MRGPRX2 and MRGPRX4), the endogenous opioid and cannabinoid balance, and phosphodiesterase 4. Periostin, a newly identified pruritogen, should be further explored with clinical trials. Drugs targeting neural sensitization including the gabergic system and P2X3 are other potential drugs for chronic itch. There is a need for more targeted therapies to improve clinical outcomes and reduce side effects.
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Affiliation(s)
- Ashley Vander Does
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA
| | - Teresa Ju
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA
| | - Noreen Mohsin
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA
| | - Divya Chopra
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA
| | - Gil Yosipovitch
- Dr Phillip Frost Department of Dermatology and Miami Itch Center, University of Miami, Miami, FL, USA.
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29
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Wu XB, Zhu Q, Gao MH, Yan SX, Gu PY, Zhang PF, Xu ML, Gao YJ. Excitatory Projections from the Prefrontal Cortex to Nucleus Accumbens Core D1-MSNs and κ Opioid Receptor Modulate Itch-Related Scratching Behaviors. J Neurosci 2023; 43:1334-1347. [PMID: 36653189 PMCID: PMC9987576 DOI: 10.1523/jneurosci.1359-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 12/28/2022] [Accepted: 01/06/2023] [Indexed: 01/20/2023] Open
Abstract
Itch is an uncomfortable and complex sensation that elicits the desire to scratch. The nucleus accumbens (NAc) activity is important in driving sensation, motivation, and emotion. Excitatory afferents from the medial prefrontal cortex (mPFC), amygdala, and hippocampus are crucial in tuning the activity of dopamine receptor D1-expressing and D2-expressing medium spiny neurons (Drd1-MSN and Drd2-MSN) in the NAc. However, a cell-type and neural circuity-based mechanism of the NAc underlying acute itch remains unclear. We found that acute itch induced by compound 48/80 (C48/80) decreased the intrinsic membrane excitability in Drd1-MSNs, but not in Drd2-MSNs, in the NAc core of male mice. Chemogenetic activation of Drd1-MSNs alleviated C48/80-induced scratching behaviors but not itch-related anxiety-like behaviors. In addition, C48/80 enhanced the frequency of spontaneous EPSCs (sEPSCs) and reduced the paired-pulse ratio (PPR) of electrical stimulation-evoked EPSCs in Drd1-MSNs. Furthermore, C48/80 increased excitatory synaptic afferents to Drd1-MSNs from the mPFC, not from the basolateral amygdala (BLA) or ventral hippocampus (vHipp). Consistently, the intrinsic excitability of mPFC-NAc projecting pyramidal neurons was increased after C48/80 treatment. Chemogenetic inhibition of mPFC-NAc excitatory synaptic afferents relieved the scratching behaviors. Moreover, pharmacological activation of κ opioid receptor (KOR) in the NAc core suppressed C48/80-induced scratching behaviors, and the modulation of KOR activity in the NAc resulted in the changes of presynaptic excitatory inputs to Drd1-MSNs in C48/80-treated mice. Together, these results reveal the neural plasticity in synapses of NAc Drd1-MSNs from the mPFC underlying acute itch and indicate the modulatory role of the KOR in itch-related scratching behaviors.SIGNIFICANCE STATEMENT Itch stimuli cause strongly scratching desire and anxiety in patients. However, the related neural mechanisms remain largely unclear. In the present study, we demonstrated that the pruritogen compound 48/80 (C48/80) shapes the excitability of dopamine receptor D1-expressing medium spiny neurons (Drd1-MSNs) in the nucleus accumbens (NAc) core and the glutamatergic synaptic afferents from medial prefrontal cortex (mPFC) to these neurons. Chemogenetic activation of Drd1-MSNs or inhibition of mPFC-NAc excitatory synaptic afferents relieves the scratching behaviors. In addition, pharmacological activation of κ opioid receptor (KOR) in the NAc core alleviates C48/80-induced itch. Thus, targeting mPFC-NAc Drd1-MSNs or KOR may provide effective treatments for itch.
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Affiliation(s)
- Xiao-Bo Wu
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Qian Zhu
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Ming-Hui Gao
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Sheng-Xiang Yan
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Pan-Yang Gu
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Peng-Fei Zhang
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Meng-Lin Xu
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Yong-Jing Gao
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
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Zhang Y, Zhao J, Hu N, Wang J, Chen X, Wang K, Yin Y. Motilin and its receptor are expressed in the dorsal horn in a rat model of acute incisional pain: Intrathecal motilin injection alleviates pain behaviors. Front Neurosci 2023; 17:1104862. [PMID: 36816129 PMCID: PMC9932669 DOI: 10.3389/fnins.2023.1104862] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 01/16/2023] [Indexed: 02/05/2023] Open
Abstract
Aims To observe the effects of intrathecal administration of motilin on pain behavior and expression of motilin (MTL)/motilin receptor (MTLR) in the spinal cord of a rat model of acute incisional pain. Methods An incisional pain model was established in rats using a unilateral plantar incision. The rats were also injected intrathecally with 1, 5, or 25 μg of motilin. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were determined. MTL/MTLR expression in the spinal cord was detected by western blotting and immunofluorescence. The expression of MTL in the spinal cord, stomach, duodenum, and plasma was determined by enzyme-linked immunosorbent assay (ELISA). Results Motilin/motilin receptor were detected in the spinal cord. Spinal cord MTL/MTLR expression peaks at 2 h after modeling (P < 0.05) and start to decrease at 24 h (P < 0.05) to almost reach baseline levels at 72 h. The changes in gastric, duodenal, plasma, and spinal cord motilin levels correlated with MWT and TWL (all R 2 > 0.82). The intrathecal injection of 1, 5, or 25 μg of motilin could increase the pain threshold of rats with incisional pain within 72 h in a dose-dependent manner. Conclusion This study showed for the first time that MTL/MTLR are expressed in rats' spinal dorsal horn. Acute pain increased MTL/MTLR expression in the spinal dorsal horn. Also, for the first time, this study showed that motilin intrathecal injection alleviates pain in rat models of acute incisional pain. These results suggest that MTL/MTLR could be a novel target for the management of acute pain.
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Affiliation(s)
- Yu Zhang
- Key Laboratory of Cancer Prevention and Therapy, Department of Anesthesiology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Tianjin, China
| | - Jun Zhao
- Department of Anesthesiology, Tianjin First Central Hospital, Nankai University, Tianjin, China
| | - Nan Hu
- Key Laboratory of Cancer Prevention and Therapy, Department of Anesthesiology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Tianjin, China
| | - Jing Wang
- Key Laboratory of Cancer Prevention and Therapy, Department of Anesthesiology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Tianjin, China
| | - Xi Chen
- Key Laboratory of Cancer Prevention and Therapy, Department of Anesthesiology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Tianjin, China
| | - Kaiyuan Wang
- Key Laboratory of Cancer Prevention and Therapy, Department of Anesthesiology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Tianjin, China,Kaiyuan Wang,
| | - Yiqing Yin
- Key Laboratory of Cancer Prevention and Therapy, Department of Anesthesiology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Tianjin, China,*Correspondence: Yiqing Yin,
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31
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Molecular recognition of itch-associated neuropeptides by bombesin receptors. Cell Res 2023; 33:184-187. [PMID: 36329202 PMCID: PMC9892485 DOI: 10.1038/s41422-022-00743-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022] Open
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32
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Gao X, Wang Z, Du L. Glial Cells and Itch: Possible Targets for Novel Antipruritic Therapies. ACS Chem Neurosci 2023; 14:331-339. [PMID: 36655585 DOI: 10.1021/acschemneuro.2c00638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Glial cells, which are the non-neuronal cells of the nervous system, play essential roles in brain development, homeostasis, and diseases. Glial cells have attracted attention because of their active involvement in many neurological disorders. In recent years, substantial progress has been made in our understanding of the roles of glial cells in the pathogenesis of itch. Mechanistically, central and peripheral glial cells modulate acute and chronic pruritus via different mechanisms. In this review, we present the current knowledge about the involvement of glial cells in the modulation of itch processing and the mechanism of glial cell activation under itch stimuli. Targeting glial cells may provide novel approaches for itch therapy.
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Affiliation(s)
- Xinyi Gao
- School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zhifei Wang
- School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Lixia Du
- Department of Biochemistry, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
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33
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Liu JJ, Li X, Guo J, Yu S, Yang S. Role of GRPR in Acupuncture Intervention in the "Itch-scratch Vicious Cycle" Spinal Circuit of Chronic Pruritus. Chin Med 2023; 18:2. [PMID: 36597164 PMCID: PMC9809006 DOI: 10.1186/s13020-022-00706-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/28/2022] [Indexed: 01/04/2023] Open
Abstract
Many previous studies have shown the potential antipruritic effect of acupuncture. This paper reviews the antipruritic mechanisms of acupuncture according to these aspects: sample characteristics, detail of intervention, and effects evaluation. The majority of research on acupuncture's antipruritic effect has focused on primary afferents of the peripheral mechanism. Relatively few studies, however, have addressed the central mechanisms. Combination the latest research achievements of chronic itch, gastrin-releasing peptide receptor (GRPR) in the dorsal horn of the spinal cord may represent the first molecule identified that is dedicated to mediating the itch response and may provide an important therapeutic target for the treatment of chronic pruritic conditions. Therefore, GRPR may be a new target for acupuncture to relieve itch in the future and provide new ideas for acupuncture intervention in the mechanisms of the spinal level of the "itch-scratch vicious cycle" of chronic itch.
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Affiliation(s)
- Jia-jia Liu
- grid.411304.30000 0001 0376 205XAcupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan China
| | - Xuemei Li
- grid.411304.30000 0001 0376 205XAcupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan China
| | - Jing Guo
- grid.411304.30000 0001 0376 205XAcupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan China
| | - Shuguang Yu
- grid.411304.30000 0001 0376 205XAcupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan China ,Key Laboratory of Sichuan Province for Acupuncture and Chronobiology, Chengdu, Sichuan China
| | - Sha Yang
- grid.411304.30000 0001 0376 205XAcupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan China ,grid.411304.30000 0001 0376 205XAcupuncture and Brain Science Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan China
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34
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Grpr expression defines a population of superficial dorsal horn vertical cells that have a role in both itch and pain. Pain 2023; 164:149-170. [PMID: 35543635 PMCID: PMC9756441 DOI: 10.1097/j.pain.0000000000002677] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/06/2022] [Indexed: 01/09/2023]
Abstract
ABSTRACT Neurons in the superficial dorsal horn that express the gastrin-releasing peptide receptor (GRPR) are strongly implicated in spinal itch pathways. However, a recent study reported that many of these correspond to vertical cells, a population of interneurons that are believed to transmit nociceptive information. In this study, we have used a GRPR CreERT2 mouse line to identify and target cells that possess Grpr mRNA. We find that the GRPR cells are highly concentrated in lamina I and the outer part of lamina II, that they are all glutamatergic, and that they account for ∼15% of the excitatory neurons in the superficial dorsal horn. We had previously identified 6 neurochemically distinct excitatory interneuron populations in this region based on neuropeptide expression and the GRPR cells are largely separate from these, although they show some overlap with cells that express substance P. Anatomical analysis revealed that the GRPR neurons are indeed vertical cells, and that their axons target each other, as well as arborising in regions that contain projection neurons: lamina I, the lateral spinal nucleus, and the lateral part of lamina V. Surprisingly, given the proposed role of GRPR cells in itch, we found that most of the cells received monosynaptic input from Trpv1-expressing (nociceptive) afferents, that the majority responded to noxious and pruritic stimuli, and that chemogenetically activating them resulted in pain-related and itch-related behaviours. Together, these findings suggest that the GRPR cells are involved in spinal cord circuits that underlie both pain and itch.
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35
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Zhang TT, Guo SS, Wang HY, Jing Q, Yi X, Hu ZH, Yu XR, Xu TL, Liu MG, Zhao X. An Anterior Cingulate Cortex-to-Midbrain Projection Controls Chronic Itch in Mice. Neurosci Bull 2022; 39:793-807. [PMID: 36528690 PMCID: PMC10169993 DOI: 10.1007/s12264-022-00996-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 08/26/2022] [Indexed: 12/23/2022] Open
Abstract
AbstractItch is an unpleasant sensation that provokes the desire to scratch. While acute itch serves as a protective system to warn the body of external irritating agents, chronic itch is a debilitating but poorly-treated clinical disease leading to repetitive scratching and skin lesions. However, the neural mechanisms underlying the pathophysiology of chronic itch remain mysterious. Here, we identified a cell type-dependent role of the anterior cingulate cortex (ACC) in controlling chronic itch-related excessive scratching behaviors in mice. Moreover, we delineated a neural circuit originating from excitatory neurons of the ACC to the ventral tegmental area (VTA) that was critically involved in chronic itch. Furthermore, we demonstrate that the ACC→VTA circuit also selectively modulated histaminergic acute itch. Finally, the ACC neurons were shown to predominantly innervate the non-dopaminergic neurons of the VTA. Taken together, our findings uncover a cortex–midbrain circuit for chronic itch-evoked scratching behaviors and shed novel insights on therapeutic intervention.
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Affiliation(s)
- Ting-Ting Zhang
- Department of Anesthesiology, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, China
| | - Su-Shan Guo
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Hui-Ying Wang
- Department of Anesthesiology, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, China
| | - Qi Jing
- Department of Anesthesiology, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, China
| | - Xin Yi
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Zi-Han Hu
- Department of Anesthesiology, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, China
| | - Xin-Ren Yu
- Department of Anesthesiology, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, China
| | - Tian-Le Xu
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Center for Brain Science of Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Ming-Gang Liu
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
- Center for Brain Science of Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
| | - Xuan Zhao
- Department of Anesthesiology, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, China.
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36
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Wu GY, Zheng XX, Zhao SL, Wang Y, Jiang S, Wang YS, Yi YL, Yao J, Wen HZ, Liu J, Li HL, Sui JF. The prelimbic cortex regulates itch processing by controlling attentional bias. iScience 2022; 26:105829. [PMID: 36619983 PMCID: PMC9816985 DOI: 10.1016/j.isci.2022.105829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 10/31/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Itch is a complex and unpleasant sensory experience. Recent studies have begun to investigate the neural mechanisms underlying the modulation of sensory and emotional components of itch in the brain. However, the key brain regions and neural mechanism involved in modulating the attentional processing of itch remain elusive. Here, we showed that the prelimbic cortex (PrL) is associated with itch processing and that the manipulation of itch-responsive neurons in the PrL significantly disrupted itch-induced scratching. Interestingly, we found that increasing attentional bias toward a distracting stimulus could disturb itch processing. We also demonstrated the existence of a population of attention-related neurons in the PrL that drive attentional bias to regulate itch processing. Importantly, itch-responsive neurons and attention-related neurons significantly overlapped in the PrL and were mutually interchangeable in the regulation of itch processing at the cellular activity level. Our results revealed that the PrL regulates itch processing by controlling attentional bias.
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Affiliation(s)
- Guang-Yan Wu
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Corresponding author
| | - Xiao-Xia Zheng
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Shan-Lan Zhao
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Yi Wang
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Shan Jiang
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Yi-Song Wang
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Yi-Lun Yi
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Juan Yao
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Hui-Zhong Wen
- Department of Neurobiology, College of Basic Medical Sciences, Chongqing Key Laboratory of Neurobiology, Army Medical University, Chongqing 400038, China
| | - Ju Liu
- Department of Foreign Languages, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Hong-Li Li
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Corresponding author
| | - Jian-Feng Sui
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China,Corresponding author
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Kim BS, Inan S, Ständer S, Sciascia T, Szepietowski JC, Yosipovitch G. Role of kappa-opioid and mu-opioid receptors in pruritus: Peripheral and central itch circuits. Exp Dermatol 2022; 31:1900-1907. [PMID: 36054458 PMCID: PMC10087456 DOI: 10.1111/exd.14669] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 08/03/2022] [Accepted: 08/15/2022] [Indexed: 12/14/2022]
Abstract
Modern genetic approaches in animal models have unveiled novel itch-specific neural pathways, emboldening a paradigm in which drugs can be developed to selectively and potently target itch in a variety of chronic pruritic conditions. In recent years, kappa-opioid receptors (KORs) and mu-opioid receptors (MORs) have been implicated in both the suppression and promotion of itch, respectively, by acting on both the peripheral and central nervous systems. The precise mechanisms by which agents that modulate these pathways alleviate itch remains an active area of investigation. Notwithstanding this, a number of agents have demonstrated efficacy in clinical trials that influence both KOR and MOR signalling. Herein, we summarize a number of opioid receptor modulators in development and their promising efficacy across a number of chronic pruritic conditions, such as atopic dermatitis, uremic pruritus and beyond.
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Affiliation(s)
- Brian S Kim
- Kimberly and Eric J. Waldman Department of Dermatology, Mark Lebwohl Center for Neuroinflammation and Sensation, Marc and Jennifer Lipschultz Precision Immunology Institute, and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Saadet Inan
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
| | - Sonja Ständer
- Department of Dermatology and Center for Chronic Pruritus, University Hospital Műnster, Műnster, Germany
| | | | - Jacek C Szepietowski
- Department of Dermatology, Venereology, and Allergology, Wroclaw Medical University, Wroclaw, Poland
| | - Gil Yosipovitch
- Dr Phillip Frost Department of Dermatology and Cutaneous Surgery, Miami Itch Center, Miller School of Medicine, University of Miami, Miami, Florida, USA
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38
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Mießner H, Seidel J, Smith ESJ. In vitro models for investigating itch. Front Mol Neurosci 2022; 15:984126. [PMID: 36385768 PMCID: PMC9644192 DOI: 10.3389/fnmol.2022.984126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 10/10/2022] [Indexed: 12/04/2022] Open
Abstract
Itch (pruritus) is a sensation that drives a desire to scratch, a behavior observed in many animals. Although generally short-lasting and not causing harm, there are several pathological conditions where chronic itch is a hallmark symptom and in which prolonged scratching can induce damage. Finding medications to counteract the sensation of chronic itch has proven difficult due to the molecular complexity that involves a multitude of triggers, receptors and signaling pathways between skin, immune and nerve cells. While much has been learned about pruritus from in vivo animal models, they have limitations that corroborate the necessity for a transition to more human disease-like models. Also, reducing animal use should be encouraged in research. However, conducting human in vivo experiments can also be ethically challenging. Thus, there is a clear need for surrogate models to be used in pre-clinical investigation of the mechanisms of itch. Most in vitro models used for itch research focus on the use of known pruritogens. For this, sensory neurons and different types of skin and/or immune cells are stimulated in 2D or 3D co-culture, and factors such as neurotransmitter or cytokine release can be measured. There are however limitations of such simplistic in vitro models. For example, not all naturally occurring cell types are present and there is also no connection to the itch-sensing organ, the central nervous system (CNS). Nevertheless, in vitro models offer a chance to investigate otherwise inaccessible specific cell–cell interactions and molecular pathways. In recent years, stem cell-based approaches and human primary cells have emerged as viable alternatives to standard cell lines or animal tissue. As in vitro models have increased in their complexity, further opportunities for more elaborated means of investigating itch have been developed. In this review, we introduce the latest concepts of itch and discuss the advantages and limitations of current in vitro models, which provide valuable contributions to pruritus research and might help to meet the unmet clinical need for more refined anti-pruritic substances.
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Affiliation(s)
- Hendrik Mießner
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
- Dermatological Skin Care, Beiersdorf AG, Hamburg, Germany
| | - Judith Seidel
- Dermatological Skin Care, Beiersdorf AG, Hamburg, Germany
| | - Ewan St. John Smith
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Ewan St. John Smith,
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Yeom M, Ahn S, Jang SY, Jang JH, Lee Y, Hahm DH, Park HJ. Acupuncture attenuates comorbid anxiety- and depressive-like behaviors of atopic dermatitis through modulating neuroadaptation in the brain reward circuit in mice. Biol Res 2022; 55:28. [PMID: 36088447 PMCID: PMC9463810 DOI: 10.1186/s40659-022-00396-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/26/2022] [Indexed: 01/21/2023] Open
Abstract
Atopic dermatitis (AD) is highly comorbid with negative emotions such as anxiety and depression. Although acupuncture has demonstrated efficacy in AD, its influence on comorbid anxiety and depression remains unclear. We sought to explore the impact and mechanisms of action of acupuncture on comorbid anxiety and depression of AD. AD-like skin lesions were induced by the topical application of MC903 to the mouse cheek. Acupuncture was performed at Gok-Ji (LI11) acupoints. AD-like phenotypes were quantified by lesion scores, scratching behavior, and histopathological changes. The effects of acupuncture on comorbid anxiety and depression-like behaviors were assessed using the elevated plus-maze (EPM), open-field tests (OFT), and tail-suspension test (TST). In addition, biochemical changes in the brain reward regions were investigated by immunoblotting for the expression of tyrosine hydroxylase (TH), dopamine D1 receptor (D1R), phospho-dopamine and cAMP-regulated phosphoprotein-32 kDa (pDARPP-32), phospho-cAMP response element binding protein (pCREB), ΔFosB, and brain-derived neurotrophic factor (BDNF) in the nucleus accumbens, dorsolateral striatum, and ventral tegmental area. Acupuncture effectively improved the chronic itching and robust AD-like skin lesions with epidermal thickening. Additionally, it considerably reduced comorbid anxiety- and depression-like symptoms, as indicated by more time spent in the open arms of the EPM and in the center of the open field and less time spent immobile in the TST. Higher pCREB, ΔFosB, BDNF, and pDARPP-32 levels, and reduced TH and D1R protein expression in the brain reward regions of AD mice were reversed by acupuncture treatment. The beneficial effects of acupuncture on clinical symptoms (scratching behavior) and comorbid psychological distress in AD strongly correlated with dorsal striatal ΔFosB levels. Collectively, these data indicate that acupuncture had a significant, positive impact on comorbid anxiety- and depression-like behaviors by modulating neuroadaptation in the brain reward circuit in mice with AD, providing a novel perspective for the non-pharmacological management of psychiatric comorbidities of AD.
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40
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Kaneko T, Kuwaki T, Kashiwadani H. Hypothalamic orexinergic neurons modulate pain and itch in an opposite way: pain relief and itch exacerbation. J Physiol Sci 2022; 72:21. [PMID: 35996084 DOI: 10.1186/s12576-022-00846-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 08/07/2022] [Indexed: 11/10/2022]
Abstract
Pain and itch are recognized as antagonistic sensations; pain suppresses itch and inhibition of pain generates itch. There is still a lack of evidence about the neural mechanism of the interaction between pain and itch in the central nervous system. In this study, we focused on the orexin (ORX) neurons in the lateral hypothalamus (LH), which mediate various "defense responses" when animals confront stressors. We found that the scratching behaviors induced by the pruritogen were significantly suppressed in ORX-neuron-ablated (ORX-abl) mice. The exaggerated pain behavior and attenuated itch behavior observed in ORX-abl mice indicated that ORX neurons modulate pain and itch in an opposite way, i.e., pain relief and itch exacerbation. In addition, most of the ORX neurons responded to both pain and itch input. Our results suggest that ORX neurons inversely regulate pain- and itch-related behaviors, which could be understood as a defense response to cope with stress environment.
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Affiliation(s)
- Tatsuroh Kaneko
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Tomoyuki Kuwaki
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Hideki Kashiwadani
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan.
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41
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Jiang S, Wang YS, Zheng XX, Zhao SL, Wang Y, Sun L, Chen PH, Zhou Y, Tin C, Li HL, Sui JF, Wu GY. Itch-specific neurons in the ventrolateral orbital cortex selectively modulate the itch processing. SCIENCE ADVANCES 2022; 8:eabn4408. [PMID: 35905177 PMCID: PMC9337765 DOI: 10.1126/sciadv.abn4408] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 06/16/2022] [Indexed: 05/31/2023]
Abstract
Itch is a cutaneous sensation that is critical in driving scratching behavior. The long-standing question of whether there are specific neurons for itch modulation inside the brain remains unanswered. Here, we report a subpopulation of itch-specific neurons in the ventrolateral orbital cortex (VLO) that is distinct from the pain-related neurons. Using a Tet-Off cellular labeling system, we showed that local inhibition or activation of these itch-specific neurons in the VLO significantly suppressed or enhanced itch-induced scratching, respectively, whereas the intervention did not significantly affect pain. Conversely, suppression or activation of pain-specific neurons in the VLO significantly affected pain but not itch. Moreover, fiber photometry and immunofluorescence verified that these itch- and pain-specific neurons are distinct in their functional activity and histological location. In addition, the downstream targets of itch- and pain-specific neurons were different. Together, the present study uncovers an important subpopulation of neurons in the VLO that specifically modulates itch processing.
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Affiliation(s)
- Shan Jiang
- Experimental Center of Basic Medicine, Army Medical University, Chongqing 400038, China
| | - Yi-Song Wang
- Experimental Center of Basic Medicine, Army Medical University, Chongqing 400038, China
| | - Xiao-Xia Zheng
- Experimental Center of Basic Medicine, Army Medical University, Chongqing 400038, China
| | - Shan-Lan Zhao
- Experimental Center of Basic Medicine, Army Medical University, Chongqing 400038, China
| | - Yi Wang
- Experimental Center of Basic Medicine, Army Medical University, Chongqing 400038, China
| | - Lin Sun
- Experimental Center of Basic Medicine, Army Medical University, Chongqing 400038, China
| | - Peng-Hui Chen
- Department of Neurobiology, Army Medical University, Chongqing 400038, China
| | - Yi Zhou
- Department of Neurobiology, Army Medical University, Chongqing 400038, China
| | - Chung Tin
- Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong, SAR, People’s Republic of China
| | - Hong-Li Li
- Experimental Center of Basic Medicine, Army Medical University, Chongqing 400038, China
| | - Jian-Feng Sui
- Experimental Center of Basic Medicine, Army Medical University, Chongqing 400038, China
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Guang-Yan Wu
- Experimental Center of Basic Medicine, Army Medical University, Chongqing 400038, China
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
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42
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Yu H, Cranfill SL, Luo W. ErbB4 + spinal cord dorsal horn neurons process heat pain. Neuron 2022; 110:2206-2208. [PMID: 35863318 DOI: 10.1016/j.neuron.2022.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
How the spinal cord transmits heat signals from the periphery to the brain remains unclear. In this issue of Neuron, Wang et al. (2022) identify a population of spinal cord neurons functioning in this pathway.
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Affiliation(s)
- Huasheng Yu
- Department of Neuroscience, 145 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Suna L Cranfill
- Department of Neuroscience, 145 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Wenqin Luo
- Department of Neuroscience, 145 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA.
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Tominaga M, Takamori K. Peripheral itch sensitization in atopic dermatitis. Allergol Int 2022; 71:265-277. [PMID: 35624035 DOI: 10.1016/j.alit.2022.04.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 04/06/2022] [Indexed: 02/07/2023] Open
Abstract
Atopic dermatitis is a skin disorder caused by skin dryness and barrier dysfunction, resulting in skin inflammation and chronic itch (or pruritus). The pathogenesis of atopic dermatitis is thought to be initiated by a lowering of the itch threshold due to dry skin. This lowering of the itch threshold is at least partially due to the increase in intraepidermal nerve fibers and sensitization of sensory nerves by interleukin (IL)-33 produced and secreted by keratinocytes. Such skin is easily prone to itch due to mechanical stimuli, such as rubbing of clothing and chemical stimuli from itch mediators. In patients with atopic dermatitis, once itch occurs, further itch is induced by scratching, and the associated scratching breaks down the skin barrier. Disruption of the skin barrier allows entry into the epidermis of external foreign substances, such as allergens derived from house dust mites, leading to an increased induction of type 2 inflammatory responses. As a result, type 2 cytokines IL-4, IL-13, and IL-31 are mainly secreted by Th2 cells, and their action on sensory nerve fibers causes further itch sensitization. These sequences of events are thought to occur simultaneously in patients with atopic dermatitis, leading to a vicious itch-scratch cycle. This vicious cycle becomes a negative spiral that leads to disease burden. Therefore, controlling itch is essential for the treatment of atopic dermatitis. In this review, we summarize and discuss advances in the mechanisms of peripheral itch sensitization in atopic dermatitis, focusing on skin barrier-neuro-immune triadic connectivity.
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44
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Zhang J, Zhou H, Li P, Shi H, Sui X, Wang Y, Shi J, Wang L. Hypothalamic response with PKA/CREB signaling is associated with direct cerebroventricular administration of bombesin-induced scratching. Brain Res 2022; 1789:147950. [PMID: 35618015 DOI: 10.1016/j.brainres.2022.147950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 04/29/2022] [Accepted: 05/19/2022] [Indexed: 11/28/2022]
Abstract
Bombesin (BN) is an itch-specific mediator that causes intense itch-scratching activity in mammals. Although most examinations of BN-induced itch processing have focused on the spinal cord, the involvement of central nervous system mechanisms remains unclear. Here, we investigated how relationships among hypothalamic regions regulate BN-mediated itch-scratch processes. We found that intracerebroventricular (i.c.v.) administration of BN (0.04-4 μg) elicited intense itch scratching in mice, whereas BN (0.4-400 μg) administered via intravenous tail injection failed to evoke a scratching response. Additionally, nalfurafine had no significant effects on BN-induced scratching behavior, indicating that central modulation of BN is distinct from histamine-mediated histaminergic itch and chloroquine-mediated non-histaminergic itch signaling pathways. We labeled BN with a fluorescent tag, 7-nitrobenz-2-oxa-1 (NBD), and traced its fluorescence in the hypothalamus for 30 min following i.c.v. NBD-BN administration. Accordingly, we confirmed that i.c.v. administration of BN enhanced c-Fos expression in the dorsal medial nucleus of the hypothalamus, where neuromedin B receptors and gastrin-releasing peptide receptors are highly expressed. Interestingly, in situ injection of BN into the hypothalamus immediately and robustly induced itch-scratching behavior. Moreover, gene transcripts and western blot assay revealed that BN receptor-dependent PKA/CREB signaling was upregulated in the hypothalamus after i.c.v. administration of BN. Consistently, pretreatment with a PKA inhibitor, Rp-cAMP, significantly reduced BN-induced scratching behavior. Our results indicate that the dorsal medial nucleus of the hypothalamus may be a key nucleus in mediating BN-mediated itch and hypothalamic PKA/CREB signaling is involved in regulating BN-mediated itch.
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Affiliation(s)
- Jingxin Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China; The Key Laboratory of Basic Pharmacology of the Educational Minister, Zunyi Medical University, Zunyi, Guizhou 563000, China.
| | - Hu Zhou
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Pengfei Li
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Huaxiang Shi
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Xin Sui
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Yongan Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Jingshan Shi
- The Key Laboratory of Basic Pharmacology of the Educational Minister, Zunyi Medical University, Zunyi, Guizhou 563000, China.
| | - Liyun Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
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45
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Ádám D, Arany J, Tóth KF, Tóth BI, Szöllősi AG, Oláh A. Opioidergic Signaling-A Neglected, Yet Potentially Important Player in Atopic Dermatitis. Int J Mol Sci 2022; 23:4140. [PMID: 35456955 PMCID: PMC9027603 DOI: 10.3390/ijms23084140] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 02/04/2023] Open
Abstract
Atopic dermatitis (AD) is one of the most common skin diseases, the prevalence of which is especially high among children. Although our understanding about its pathogenesis has substantially grown in recent years, and hence, several novel therapeutic targets have been successfully exploited in the management of the disease, we still lack curative treatments for it. Thus, there is an unmet societal demand to identify further details of its pathogenesis to thereby pave the way for novel therapeutic approaches with favorable side effect profiles. It is commonly accepted that dysfunction of the complex cutaneous barrier plays a central role in the development of AD; therefore, the signaling pathways involved in the regulation of this quite complex process are likely to be involved in the pathogenesis of the disease and can provide novel, promising, yet unexplored therapeutic targets. Thus, in the current review, we aim to summarize the available potentially AD-relevant data regarding one such signaling pathway, namely cutaneous opioidergic signaling.
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Affiliation(s)
- Dorottya Ádám
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - József Arany
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Kinga Fanni Tóth
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Balázs István Tóth
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
| | - Attila Gábor Szöllősi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary;
| | - Attila Oláh
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
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Lesslar OJL, Smith PK. Itch Beyond the Skin-Mucosal Itch. FRONTIERS IN ALLERGY 2022; 2:700368. [PMID: 35386995 PMCID: PMC8974814 DOI: 10.3389/falgy.2021.700368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 09/07/2021] [Indexed: 11/13/2022] Open
Abstract
Itch is a nociceptive sensation linked with reflexes and cognitive motor actions. We traditionally think of itch as a sensation of the skin related to allergy, an insect sting or interestingly, anxiety and frustration. Less understood and considered are the physiological processes involved in the itching sensation that occurs at mucosal and junctional dermal sites, which is extraordinary as from an evolutionary point of view these sites serve important guardian roles, rich in sensory nerves and inflammatory cells. Despite itch being an ancient reflex and evolutionarily conserved phenomenon, better clinical understanding of the nuances between sites of itch sensation may lead to improved clinical outcomes. This review invites readers to appreciate itch beyond the skin by highlighting several specific itch patterns-nasal, oral, auricular, vulvovaginal, anal, and perineal itch-the pathophysiological mechanisms that underlie them, the clinical patterns these may cause, and some unique treatments.
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Affiliation(s)
- Olivia J Ly Lesslar
- LifeSpan Medicine, Los Angeles, CA, United States.,Cingulum Health, Sydney, NSW, Australia
| | - Peter K Smith
- Clinical Medicine, Griffith University, Southport, QLD, Australia
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Saeki A, Yamanaka H, Kobayashi K, Okubo M, Noguchi K. Analgesic effect of gastrin-releasing peptide in the dorsal horn. Mol Pain 2022; 18:17448069221108965. [PMID: 35815426 PMCID: PMC9277428 DOI: 10.1177/17448069221108965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Itch and pain are both unpleasant, but they are discrete sensations. Both of these
sensations are transmitted by C-fibers and processed in laminae I-II of the dorsal horn.
To examine whether pruriception modulates pain, we first confirmed the activation of cells
in the itch-related circuits that were positive for gastrin-releasing peptide (GRP) and
GRP receptor (GRPR) using a paw formalin injection model. This pain model with typical
biphasic pain behavior increased c-Fos but did not affect the expressions of
GRP and GRPR mRNAs in the dorsal horn. Using c-Fos
expression as a marker for activated cells, we confirmed that formalin injection increased
the number of cells double-labeled for c-Fos and GRP or GRPR in the dorsal horn. The
emergence of these neurons indicates the activation of itch-related circuits by acute pain
signals. The effect of an antagonist for a GRPR was examined in the paw formalin injection
model. Intrathecal chronic antagonization of spinal GRPR enhanced the onset of phase II of
paw formalin injection-induced pain behavior. Exogenous intrathecal GRP infusion to the
paw-formalin injection model not only showed significant reduction of pain behavior but
also increased c-Fos in the inhibitory neurons in the dorsal horn. The anti-nociceptive
effect of spinal GRP infusion was observed in the peripheral inflammation model (complete
Freund’s adjuvant injection model). In this study we suggest that painful stimuli
activated itch-related neuronal circuits and uncovered the spinal activation of the
itch-induced analgesic effect on acute and established inflammatory pain.
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Affiliation(s)
- Ayano Saeki
- Department of Anatomy and Neuroscience, Faculty of Medicine, 12818Hyogo Medical University, Nishinomiya, Hyogo, Japan.,Department of Anesthesiology and Pain Medicine, Faculty of Medicine, 12818Hyogo Medical University, Nishinomiya, Hyogo, Japan
| | - Hiroki Yamanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, 12818Hyogo Medical University, Nishinomiya, Hyogo, Japan
| | - Kimiko Kobayashi
- Department of Anatomy and Neuroscience, Faculty of Medicine, 12818Hyogo Medical University, Nishinomiya, Hyogo, Japan
| | - Masamichi Okubo
- Department of Anatomy and Neuroscience, Faculty of Medicine, 12818Hyogo Medical University, Nishinomiya, Hyogo, Japan
| | - Koichi Noguchi
- Department of Anatomy and Neuroscience, Faculty of Medicine, 12818Hyogo Medical University, Nishinomiya, Hyogo, Japan
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48
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Tang Y, Cheng S, Wang J, Jin Y, Yang H, Lin Q, Xu S, Hui L, Yin Q, Yang Y, Wu X. Acupuncture for the Treatment of Itch: Peripheral and Central Mechanisms. Front Neurosci 2022; 15:786892. [PMID: 35431769 PMCID: PMC9005788 DOI: 10.3389/fnins.2021.786892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/13/2021] [Indexed: 11/21/2022] Open
Abstract
Despite the widespread clinical use of acupuncture in the treatment of pruritus caused by psoriasis, urticaria, uremic, and other diseases, insights into the mechanism of action of acupuncture are still emerging. For the above reasons, a beneficial effect of acupuncture on pruritus was not recommended or reported in recent clinical practice guidelines. Acupuncture is a kind of physical stimulation, which has the characteristics of multi-channel and multi-target effects. The biomechanical stimulation signal of acupuncture needling can be transformed into bioelectric and chemical signals; interfere with kinds of cells and nerve fibers in the skin and muscle; alter signaling pathways and transcriptional activity of cells, mediators, and receptors; and result in inhibition of peripheral and central transmission of pruritus. Available mechanistic data give insights into the biological regulation potency of acupuncture for pruritus and provide a basis for more in-depth and comprehensive mechanism research.
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Steinhoff M, Ahmad F, Pandey A, Datsi A, AlHammadi A, Al-Khawaga S, Al-Malki A, Meng J, Alam M, Buddenkotte J. Neuro-immune communication regulating pruritus in atopic dermatitis. J Allergy Clin Immunol 2022; 149:1875-1898. [PMID: 35337846 DOI: 10.1016/j.jaci.2022.03.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 02/13/2022] [Accepted: 03/10/2022] [Indexed: 11/26/2022]
Abstract
Atopic dermatitis (AD) is a common, chronic-relapsing inflammatory skin disease with significant disease burden. Genetic and environmental trigger factors contribute to AD, activating two of our largest organs, the nervous and immune system. Dysregulation of neuro-immune circuits plays a key role in the pathophysiology of AD causing inflammation, pruritus, pain, and barrier dysfunction. Sensory nerves can be activated by environmental or endogenous trigger factors transmitting itch stimuli to the brain. Upon stimulation, sensory nerve endings also release neuromediators into the skin contributing again to inflammation, barrier dysfunction and itch. Additionally, dysfunctional peripheral and central neuronal structures contribute to neuroinflammation, sensitization, nerve elongation, neuropathic itch, thus chronification and therapy-resistance. Consequently, neuro-immune circuits in skin and central nervous system may be targets to treat pruritus in AD. Cytokines, chemokines, proteases, lipids, opioids, ions excite/sensitize sensory nerve endings not only induce itch but further aggravate/perpetuate inflammation, skin barrier disruption, and pruritus. Thus, targeted therapies for neuro-immune circuits as well as pathway inhibitors (e.g., kinase inhibitors) may be beneficial to control pruritus in AD either in systemic and/or topical form. Understanding neuro-immune circuits and neuronal signaling will optimize our approach to control all pathological mechanisms in AD, inflammation, barrier dysfunction and pruritus.
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Affiliation(s)
- Martin Steinhoff
- Department of Dermatology and Venereology, Hamad Medical Corporation, Doha, Qatar; Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar; Dermatology Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar; Department of Dermatology, Weill Cornell Medicine-Qatar, Doha, Qatar; Qatar University, College of Medicine, Doha, Qatar; Department of Dermatology, Weill Cornell Medicine, New York, USA.
| | - Fareed Ahmad
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar; Dermatology Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Atul Pandey
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar; Dermatology Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Angeliki Datsi
- Institute for Transplantational Diagnostics and Cell Therapeutics, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Ayda AlHammadi
- Department of Dermatology and Venereology, Hamad Medical Corporation, Doha, Qatar
| | - Sara Al-Khawaga
- Department of Dermatology and Venereology, Hamad Medical Corporation, Doha, Qatar
| | - Aysha Al-Malki
- Department of Dermatology and Venereology, Hamad Medical Corporation, Doha, Qatar
| | - Jianghui Meng
- National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland
| | - Majid Alam
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar; Dermatology Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Joerg Buddenkotte
- Department of Dermatology and Venereology, Hamad Medical Corporation, Doha, Qatar; Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar; Dermatology Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
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Slick Potassium Channels Control Pain and Itch in Distinct Populations of Sensory and Spinal Neurons in Mice. Anesthesiology 2022; 136:802-822. [PMID: 35303056 DOI: 10.1097/aln.0000000000004163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Slick, a sodium-activated potassium channel, has been recently identified in somatosensory pathways, but its functional role is poorly understood. The authors of this study hypothesized that Slick is involved in processing sensations of pain and itch. METHODS Immunostaining, in situ hybridization, Western blot, and real-time quantitative reverse transcription polymerase chain reaction were used to investigate the expression of Slick in dorsal root ganglia and the spinal cord. Mice lacking Slick globally (Slick-/-) or conditionally in neurons of the spinal dorsal horn (Lbx1-Slick-/-) were assessed in behavioral models. RESULTS The authors found Slick to be enriched in nociceptive Aδ-fibers and in populations of interneurons in the spinal dorsal horn. Slick-/- mice, but not Lbx1-Slick-/- mice, showed enhanced responses to noxious heat in the hot plate and tail-immersion tests. Both Slick-/- and Lbx1-Slick-/- mice demonstrated prolonged paw licking after capsaicin injection (mean ± SD, 45.6 ± 30.1 s [95% CI, 19.8 to 71.4]; and 13.1 ± 16.1 s [95% CI, 1.8 to 28.0]; P = 0.006 [Slick-/- {n = 8} and wild-type {n = 7}, respectively]), which was paralleled by increased phosphorylation of the neuronal activity marker extracellular signal-regulated kinase in the spinal cord. In the spinal dorsal horn, Slick is colocalized with somatostatin receptor 2 (SSTR2), and intrathecal preadministration of the SSTR2 antagonist CYN-154806 prevented increased capsaicin-induced licking in Slick-/- and Lbx1-Slick-/- mice. Moreover, scratching after intrathecal delivery of the somatostatin analog octreotide was considerably reduced in Slick-/- and Lbx1-Slick-/- mice (Slick-/- [n = 8]: 6.1 ± 6.7 bouts [95% CI, 0.6 to 11.7]; wild-type [n =8]: 47.4 ± 51.1 bouts [95% CI, 4.8 to 90.2]; P = 0.039). CONCLUSIONS Slick expressed in a subset of sensory neurons modulates heat-induced pain, while Slick expressed in spinal cord interneurons inhibits capsaicin-induced pain but facilitates somatostatin-induced itch. EDITOR’S PERSPECTIVE
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