1
|
Kuo CC, McCall JG. Neural circuit-selective, multiplexed pharmacological targeting of prefrontal cortex-projecting locus coeruleus neurons drives antinociception. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.08.598059. [PMID: 38895281 PMCID: PMC11185789 DOI: 10.1101/2024.06.08.598059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Selective manipulation of neural circuits using optogenetics and chemogenetics holds great translational potential but requires genetic access to neurons. Here, we demonstrate a general framework for identifying genetic tool-independent, pharmacological strategies for neural circuit-selective modulation. We developed an economically accessible calcium imaging-based approach for large-scale pharmacological scans of endogenous receptor-mediated neural activity. As a testbed for this approach, we used the mouse locus coeruleus due to the combination of its widespread, modular efferent neural circuitry and its wide variety of endogenously expressed GPCRs. Using machine learning-based action potential deconvolution and retrograde tracing, we identified an agonist cocktail that selectively inhibits medial prefrontal cortex-projecting locus coeruleus neurons. In vivo, this cocktail produces synergistic antinociception, consistent with selective pharmacological blunting of this neural circuit. This framework has broad utility for selective targeting of other neural circuits under different physiological and pathological states, facilitating non-genetic translational applications arising from cell type-selective discoveries.
Collapse
Affiliation(s)
- Chao-Cheng Kuo
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, USA; Center for Clinical Pharmacology, University of Health Sciences and Pharmacy in St. Louis and Washington University School of Medicine, St. Louis, MO, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO, USA
| | - Jordan G. McCall
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, USA; Center for Clinical Pharmacology, University of Health Sciences and Pharmacy in St. Louis and Washington University School of Medicine, St. Louis, MO, USA; Washington University Pain Center, Washington University in St. Louis, St. Louis, MO, USA
| |
Collapse
|
2
|
Yang YY, Du LX, Zhu JY, Yi T, Yang YC, Qiao Z, Maoying QL, Chu YX, Wang YQ, Mi WL. Antipruritic effects of geraniol on acute and chronic itch via modulating spinal GABA/GRPR signaling. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 119:154969. [PMID: 37516088 DOI: 10.1016/j.phymed.2023.154969] [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: 01/20/2023] [Revised: 06/12/2023] [Accepted: 07/15/2023] [Indexed: 07/31/2023]
Abstract
BACKGROUND AND PURPOSE Itch (pruritus) is a common unpleasant feeling, often accompanied by the urge of scratching the skin. It is the main symptom of many systemic and skin diseases, which can seriously affect the patient's quality of life. Geraniol (GE; trans-3,7-dimethyl-2,6-octadien-1-ol) is a natural monoterpene with diverse effects, including anti-inflammatory, antioxidant, neuroprotective, anti-nociceptive, and anticancer properties. The study aims to examine the effects of GE on acute and chronic itch, and explore the underlying mechanisms. METHODS Acute itch was investigated by using Chloroquine and compound 48/80 induced model, followed by manifestation of diphenylcyclopropenone (DCP)-induced allergic contact dermatitis and the acetone-ether-water (AEW)-induced dry skin model in mice. The scratching behavior, skin thickness, c-Fos expression, and GRPR protein expression in the spinal cord were subsequently monitored and evaluated by behavioral tests as well as pharmacological and pharmacogenetic technologies. RESULTS Dose-dependent intraperitoneal injection of GE alleviated the acute itch, induced by chloroquine and compound 48/80, as well as increased the spinal c-Fos expression. Intrathecal administration of GE suppressed the GABAA receptor inhibitor bicuculline-induced itch, GRP-induced itch, and the GABAergic neuron inhibition-induced itch. Furthermore, the subeffective dose of bicuculline blocked the anti-pruritic effect of GE on the chloroquine and compound 48/80 induced acute itch. GE also attenuated DCP and AEW-induced chronic itch, as well as the increase of spinal GRPR expression in DCP mice. CONCLUSION AND IMPLICATIONS GE alleviates both acute and chronic itch via modulating the spinal GABA/GRPR signaling in mice. Findings of this study reveal that GE may provide promising therapeutic options for itch management. Also, considering the pivotal role of essential oils in aromatherapy, GE has great application potential in aromatherapy for treating skin diseases, and especially the skin with severe pruritus.
Collapse
Affiliation(s)
- Ya-Yue Yang
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Li-Xia Du
- Department of Biochemistry, School of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jian-Yu Zhu
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Ting Yi
- Chinese Medicine Research Institute, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Ya-Chen Yang
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Zheng Qiao
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Qi-Liang Maoying
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yu-Xia Chu
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yan-Qing Wang
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Wen-Li Mi
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Science; Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai 200032, China.
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Long JH, Wang PJ, Li ZF, Yao J, Li X, Wu B, Sui JF, Liao J, Wang P, Li XF, Liu SL. Dysgranular retrosplenial cortex modulates histaminergic and nonhistaminergic itch processing. Behav Brain Res 2023; 443:114306. [PMID: 36682500 DOI: 10.1016/j.bbr.2023.114306] [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: 11/18/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/22/2023]
Abstract
Itch is an unpleasant sensation followed by an intense desire to scratch. Previous researches have advanced our understanding about the role of anterior cingulate cortex and prelimbic cortex in itch modulation, whereas little is known about the effects of retrosplenial cortex (RSC) during this process. Here we firstly confirmed that the neuronal activity of dysgranular RSC (RSCd) is significantly elevated during itch-scratching processing through c-Fos immunohistochemistry and fiber photometry recording. Then with designer receptors exclusively activated by designer drugs approaches, we found that pharmacogenetic inhibition of global RSCd neurons attenuated the number of scratching bouts as well as the cumulative duration of scratching bouts elicited by both 5-HT or compound 48/80 injection into rats' nape or cheek; selective inhibition of the pyramidal neurons in RSCd, or of the excitatory projections from caudal anterior cingulate cortex (cACC) to RSCd, demonstrated the similar effects of decreasing itch-related scratching induced by both 5-HT or compound 48/80. Pharmacogenetic intervention of the neuronal or circuitry activities did not affect rats' motor ability. This study presents direct evidence that pyramidal neurons in RSCd, and the excitatory projection from cACC to RSCd are critically involved in central regulation of both histaminergic and nonhistaminergic itch.
Collapse
Affiliation(s)
- Jun-Hui Long
- Department of Dermatology, The 958th Army Hospital of the Chinese People's Liberation Army, China
| | - Pu-Jun Wang
- Department of Dermatology, The 958th Army Hospital of the Chinese People's Liberation Army, China
| | - Zhi-Fang Li
- Department of Foreign Languages, 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
| | - Xuan Li
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Bing Wu
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Jian-Feng Sui
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Jun Liao
- Department of Dermatology, The 958th Army Hospital of the Chinese People's Liberation Army, China
| | - Ping Wang
- Department of Dermatology, The 958th Army Hospital of the Chinese People's Liberation Army, China
| | - Xiao-Feng Li
- Department of Radiology, the Third Affiliated Hospital of Chongqing Medical University, Chongqing 401120, China.
| | - Shu-Lei Liu
- Department of Dermatology, The 958th Army Hospital of the Chinese People's Liberation Army, China.
| |
Collapse
|
5
|
Kozar-Gillan N, Velichkova A, Kanatouris G, Eshed-Eisenbach Y, Steel G, Jaegle M, Aunin E, Peles E, Torsney C, Meijer DN. LGI3/2-ADAM23 interactions cluster Kv1 channels in myelinated axons to regulate refractory period. J Cell Biol 2023; 222:e202211031. [PMID: 36828548 PMCID: PMC9997507 DOI: 10.1083/jcb.202211031] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/18/2022] [Accepted: 01/17/2023] [Indexed: 02/26/2023] Open
Abstract
Along myelinated axons, Shaker-type potassium channels (Kv1) accumulate at high density in the juxtaparanodal region, directly adjacent to the paranodal axon-glia junctions that flank the nodes of Ranvier. However, the mechanisms that control the clustering of Kv1 channels, as well as their function at this site, are still poorly understood. Here we demonstrate that axonal ADAM23 is essential for both the accumulation and stability of juxtaparanodal Kv1 complexes. The function of ADAM23 is critically dependent on its interaction with its extracellular ligands LGI2 and LGI3. Furthermore, we demonstrate that juxtaparanodal Kv1 complexes affect the refractory period, thus enabling high-frequency burst firing of action potentials. Our findings not only reveal a previously unknown molecular pathway that regulates Kv1 channel clustering, but they also demonstrate that the juxtaparanodal Kv1 channels that are concealed below the myelin sheath, play a significant role in modifying axonal physiology.
Collapse
Affiliation(s)
- Nina Kozar-Gillan
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
| | | | - George Kanatouris
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
| | - Yael Eshed-Eisenbach
- Department of Molecular Cell Biology and Molecular Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Gavin Steel
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
| | | | - Eerik Aunin
- Biomedical Sciences, ErasmusMC, Rotterdam, Netherlands
| | - Elior Peles
- Department of Molecular Cell Biology and Molecular Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Carole Torsney
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh. UK
| | - Dies N. Meijer
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh. UK
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
6
|
Chen QY, Zhuo M. Glutamate acts as a key neurotransmitter for itch in the mammalian spinal cord. Mol Pain 2023; 19:17448069231152101. [PMID: 36604775 PMCID: PMC9846298 DOI: 10.1177/17448069231152101] [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] [Indexed: 01/07/2023] Open
Abstract
Itch sensation is one of the major sensory experiences of humans and animals. Recent studies using genetic deletion techniques have proposed that gastrin-releasing peptide (GRP) is a key neurotransmitter for itch in the spinal cord. However, these studies are mainly based on behavioral responses and lack direct electrophysiological evidence that GRP indeed mediates itch information between primary afferent fibers and spinal dorsal horn neurons. In this review, we reviewed recent studies using different experimental approaches and proposed that glutamate but not GRP acts as the key neurotransmitter in the primary afferents in the transmission of itch. GRP is more likely to serve as an itch-related neuromodulator. In the cerebral cortex, we propose that the anterior cingulate cortex (ACC) plays a significant role in both itch and pain sensations. Only behavioral measurement of itch (scratching) is not sufficient for itch measurement, since scratching the itching area also produces pleasure. Integrative experimental approaches as well as better behavioral scoring models are needed to help to understand the neuronal mechanism of itch and aid future treatment for patients with pruritic diseases.
Collapse
Affiliation(s)
- Qi-Yu Chen
- Qingdao International Academician
Park, International Institute for Brain
Research, Qingdao, China,CAS Key Laboratory of Brain
Connectome and Manipulation, Interdisciplinary Center for Brain Information, The
Brain Cognition and Brain Disease Institute, Shenzhen-Hong Kong Institute of
Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen Institute of
Advanced Technology, Chinese Academy of Sciences Shenzhen
Institute of Advanced Technology, Shenzhen, China
| | - Min Zhuo
- Qingdao International Academician
Park, International Institute for Brain
Research, Qingdao, China,Department of Physiology, Faculty
of Medicine, University of Toronto, Toronto, ON, Canada,Min Zhuo, Institute of Brain Research,
Qingdao International Academician Park, Qingdao 266199, China.
| |
Collapse
|
7
|
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.
Collapse
|
8
|
Comitato A, Lacivita E, Leopoldo M, Bardoni R. 5-HT7 Receptors Regulate Excitatory-Inhibitory Balance in Mouse Spinal Cord Dorsal Horn. Front Mol Neurosci 2022; 15:946159. [PMID: 35875663 PMCID: PMC9298498 DOI: 10.3389/fnmol.2022.946159] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/13/2022] [Indexed: 11/30/2022] Open
Abstract
Serotonergic receptors of the 5-HT7 type (5-HT7Rs) are widely expressed in the central nervous system (CNS), where they modulate several functions, such as pain. Behavioral experiments in vivo have shown both anti- and pro-nociceptive actions of 5-HT7Rs, although an analgesic effect seems to be prevalent. In the spinal cord dorsal horn, the mechanisms involved in 5-HT7R-mediated synaptic modulation are still poorly understood, especially those regarding the control of synaptic inhibition. The present study investigated the modulation exerted by 5-HT7Rs on dorsal horn excitatory and inhibitory synaptic circuits, by performing patch-clamp recordings from lamina II neurons in mouse spinal cord slices. Our results show that applying the selective 5-HT7 agonist LP-211 facilitates glutamatergic release by enhancing the frequency of spontaneous postsynaptic currents (sEPSCs) and increasing the peak amplitude of excitatory postsynaptic currents (EPSCs) evoked by dorsal root stimulation. The effects on sEPSCs were still observed in the presence of the 5-HT1A antagonist WAY-100635, while the 5-HT7 antagonist SB-269970 blocked them. LP-211 was also able to increase the release of gamma-aminobutyric acid (GABA) and glycine, as shown by the increase of spontaneous inhibitory currents (sIPSC) frequency and evoked inhibitory postsynaptic currents (IPSC) amplitude. LP-211 was proved to be more effective in potentiating synaptic inhibition as compared to excitation: consistently, 5-HT7R activation significantly enhanced the excitability of tonic firing neurons, mainly corresponding to inhibitory interneurons. Our data bring new insights into the mechanisms of synaptic modulation mediated by 5-HT7Rs in the dorsal horn. Stronger impact on synaptic inhibition supports the hypothesis that these receptors may play an anti-nociceptive role in the spinal cord of naïve animals.
Collapse
Affiliation(s)
- Antonella Comitato
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Enza Lacivita
- Department of Pharmacy – Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Marcello Leopoldo
- Department of Pharmacy – Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Rita Bardoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- *Correspondence: Rita Bardoni,
| |
Collapse
|
9
|
Kanehisa K, Koga K, Maejima S, Shiraishi Y, Asai K, Shiratori-Hayashi M, Xiao MF, Sakamoto H, Worley PF, Tsuda M. Neuronal pentraxin 2 is required for facilitating excitatory synaptic inputs onto spinal neurons involved in pruriceptive transmission in a model of chronic itch. Nat Commun 2022; 13:2367. [PMID: 35501343 PMCID: PMC9061767 DOI: 10.1038/s41467-022-30089-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 04/14/2022] [Indexed: 11/08/2022] Open
Abstract
An excitatory neuron subset in the spinal dorsal horn (SDH) that expresses gastrin-releasing peptide receptors (GRPR) is critical for pruriceptive transmission. Here, we show that glutamatergic excitatory inputs onto GRPR+ neurons are facilitated in mouse models of chronic itch. In these models, neuronal pentraxin 2 (NPTX2), an activity-dependent immediate early gene product, is upregulated in the dorsal root ganglion (DRG) neurons. Electron microscopy reveals that NPTX2 is present at presynaptic terminals connected onto postsynaptic GRPR+ neurons. NPTX2-knockout prevents the facilitation of synaptic inputs to GRPR+ neurons, and repetitive scratching behavior. DRG-specific NPTX2 expression rescues the impaired behavioral phenotype in NPTX2-knockout mice. Moreover, ectopic expression of a dominant-negative form of NPTX2 in DRG neurons reduces chronic itch-like behavior in mice. Our findings indicate that the upregulation of NPTX2 expression in DRG neurons contributes to the facilitation of glutamatergic inputs onto GRPR+ neurons under chronic itch-like conditions, providing a potential therapeutic target.
Collapse
Affiliation(s)
- Kensho Kanehisa
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Keisuke Koga
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
- Department of Neurophysiology, Hyogo College of Medicine, Nishinomiya, Hyogo, 663-8501, Japan
| | - Sho Maejima
- Ushimado Marine Institute, Graduate School of Natural Science and Technology, Okayama University, 130-17 Kashino, Ushimado, Setouchi, 701-4303, Japan
| | - Yuto Shiraishi
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Konatsu Asai
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Miho Shiratori-Hayashi
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Mei-Fang Xiao
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States
| | - Hirotaka Sakamoto
- Ushimado Marine Institute, Graduate School of Natural Science and Technology, Okayama University, 130-17 Kashino, Ushimado, Setouchi, 701-4303, Japan
| | - Paul F Worley
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States
| | - Makoto Tsuda
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Bardoni R. Experimental Protocols and Analytical Procedures for Studying Synaptic Transmission in Rodent Spinal Cord Dorsal Horn. Curr Protoc 2022; 2:e409. [PMID: 35435326 DOI: 10.1002/cpz1.409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Synaptic modulation and plasticity are key mechanisms underlying pain transmission in the spinal cord and supra-spinal centers. The study and understanding of these phenomena are fundamental to investigating both acute nociception and maladaptive changes occurring in chronic pain. This article describes experimental protocols and analytical methods utilized in electrophysiological studies to investigate synaptic modulation and plasticity at the first station of somatosensory processing, the spinal cord dorsal horn. Protocols useful for characterizing the nature of synaptic inputs, the site of modulation (pre- versus postsynaptic), and the presence of short-term synaptic plasticity are presented. These methods can be employed to study the physiology of acute nociception, the pathological mechanisms of persistent inflammatory and neuropathic pain, and the pharmacology of receptors and channels involved in pain transmission. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Spinal cord dissection and acute slice preparation Basic Protocol 2: Stimulation of the dorsal root and extracellular recording (compound action potentials and field potentials) Basic Protocol 3: Patch-clamp recording from dorsal horn neurons: action potential firing patterns and evoked synaptic inputs Basic Protocol 4: Analysis of parameters responsible for changes in synaptic efficacy Basic Protocol 5: Recording and analysis of currents mediated by astrocytic glutamate.
Collapse
Affiliation(s)
- Rita Bardoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Campi, Modena, Italy
| |
Collapse
|
12
|
Chen M, He T, Yi XH, Tang MC, Long JH, Wang PJ, Liu J, Yao J, Li HL, Sui JF, Wu GY. Infralimbic cortex–medial striatum projections modulate the itch processing. Exp Neurol 2022; 354:114101. [DOI: 10.1016/j.expneurol.2022.114101] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 03/11/2022] [Accepted: 04/26/2022] [Indexed: 11/04/2022]
|
13
|
Piyush Shah D, Barik A. The Spino-Parabrachial Pathway for Itch. Front Neural Circuits 2022; 16:805831. [PMID: 35250493 PMCID: PMC8891797 DOI: 10.3389/fncir.2022.805831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 01/03/2022] [Indexed: 11/13/2022] Open
Abstract
Itch-induced scratching is an evolutionarily conserved behavioral response that protects organisms from potential parasites/irritants in their immediate vicinity. How the exposure to a pruritogen is translated to the perception of itch and how that perception drives scratching directed towards the site of exposure remains poorly understood. In this review, we focus on the recent findings that shed light on the neural pathways in the brain that underlie itch-induced scratching. We compare the molecularly defined itch pathways with the known pain circuits as they have anatomical and functional overlap. We review the roles played by the neurons in the spinoparabrachial pathway-comprising of the neurons in the spinal cord and the parabrachial nucleus (PBN), which acts as a hub for transmitting itch information across the brain. Lastly, we deliberate on scratching as a behavioral measure of the intensity of itch and its implication in unraveling the underlying supraspinal mechanisms. In summary, we provide a resource on the recent advances and discuss a path forward on our understanding of the neural circuits for itch.
Collapse
Affiliation(s)
| | - Arnab Barik
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| |
Collapse
|
14
|
Abstract
Itch is one of the most primal sensations, being both ubiquitous and important for the well-being of animals. For more than a century, a desire to understand how itch is encoded by the nervous system has prompted the advancement of many theories. Within the past 15 years, our understanding of the molecular and neural mechanisms of itch has undergone a major transformation, and this remarkable progress continues today without any sign of abating. Here I describe accumulating evidence that indicates that itch is distinguished from pain through the actions of itch-specific neuropeptides that relay itch information to the spinal cord. According to this model, classical neurotransmitters transmit, inhibit and modulate itch information in a context-, space- and time-dependent manner but do not encode itch specificity. Gastrin-releasing peptide (GRP) is proposed to be a key itch-specific neuropeptide, with spinal neurons expressing GRP receptor (GRPR) functioning as a key part of a convergent circuit for the conveyance of peripheral itch information to the brain.
Collapse
|
15
|
Shen KF, Yang XL, Liu GL, Zhu G, Wang ZK, Shi XJ, Wang TT, Wu ZF, Lv SQ, Liu SY, Yang H, Zhang CQ. The role of voltage-gated chloride channels in the epileptogenesis of temporal lobe epilepsy. EBioMedicine 2021; 70:103537. [PMID: 34391093 PMCID: PMC8365373 DOI: 10.1016/j.ebiom.2021.103537] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/18/2021] [Accepted: 07/29/2021] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Temporal lobe epilepsy (TLE) is the most common intractable epilepsy in adults, and elucidation of the underlying pathological mechanisms is needed. Voltage-gated chloride channels (ClC) play diverse physiological roles in neurons. However, less is known regarding their functions in the epilepogenesis of TLE. METHODS ClC-mediated current and the spontaneous inhibitory synaptic currents (sIPSC) in hippocampal neurons of epileptic lesions were investigated by electrophysiological recording. The EEG data were analyzed by Z-scored wavelet and Fourier transformations. The expression of ClC-3, a member of ClC gene family, was detected by immunostaining and western blot. FINDINGS ClC-mediated current was increased in the hippocampal neurons of chronic TLE mice. Application of chloride channel blockers, NPPB (5-Nitro-2- [3-phenylpropylamino] benzoic acid) and DIDS (4,4'-Diisothiocyanato-2,2'-stilbenedisulfonic acid disodium salt) reduced ClC-mediated current and increased inhibitory synaptic transmission in TLE mice. NPPB and DIDS reduced the seizure frequency and the average absolute power of ictal high-frequency oscillations (HFOs, 80-500 Hz) in TLE mice. In addition, both drugs induced outwardly rectified currents, which might be tonic inhibitory currents in the hippocampal neurons of TLE patients. Furthermore, the expression of ClC-3 was increased in the hippocampus of TLE mice and patients and positively correlated with both the absolute power and number of ictal HFOs per seizure in the sclerotic hippocampus. INTERPRETATION These data suggest that ClC participate in the epilepogenetic process of TLE and the inhibition of ClC may have anti-epileptic effect. FUNDING This work was supported by National Natural Science Foundation of China (No. 81601143, No. 81771217).
Collapse
Affiliation(s)
- Kai-Feng Shen
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Xiao-Lin Yang
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Guo-Long Liu
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Gang Zhu
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Zhong-Ke Wang
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Xian-Jun Shi
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Ting-Ting Wang
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Zhi-Feng Wu
- Department of Pediatrics, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Sheng-Qing Lv
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Shi-Yong Liu
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Hui Yang
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China
| | - Chun-Qing Zhang
- Department of Neurosurgery, Xinqiao Hospital, Army Medical University, 2-V Xinqiao Street, Chongqing 400037, China.
| |
Collapse
|
16
|
Abstract
PURPOSE OF REVIEW The current review aims to update the important findings about molecular and cellular biology of mammalian bombesin-like peptides (BLPs) and their receptors. RECENT FINDINGS Recent identification of synaptic communication between gastrin-releasing peptide (GRP) neurons and GRP receptor (GRPR) neurons in spinal itch relay provides us novel insights into physiology of itch sensation. Neuromedin B (NMB) neurons were found to form connections with subcortical areas associated with arousal, hippocampal theta oscillation, and premotor processing and project to multiple downstream stations to regulate locomotion and hippocampal theta power. In addition to researches regarding the roles of BLPs and their receptors in central nervous system, recent findings reveal that NMB receptor is expressed on helminth-induced type 2 innate lymphoid cells and is regulated by basophils, suggesting an important function of NMB in helminth-induced immune responses. Bombesin transactivates epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and HER3 receptors on human nonsmall-cell lung cancer (NSCLC) cells and elicits downstream signaling cascades and induces formation of both human epidermal growthfactor receptor 3 (HER3)/EGFR and HER3/HER2 heterodimers. Several high-affinity ligands for bombesin receptors were characterized, providing useful tools in investigation of biological roles of those peptides and their receptors. SUMMARY The most exciting findings of BLPs and their receptors in the past year come from studies in central nervous system. In addition, more researches are still underway to probe the molecular mechanisms of those peptides in peripheral tissues and characterize novel synthetic ligands with high affinity for mammalian bombesin receptors.
Collapse
Affiliation(s)
- Xiaoqun Qin
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, PR China
| | | |
Collapse
|
17
|
Li Y, Su S, Yu J, Peng M, Wan S, Ke C. Electrophysiological Properties of Substantia Gelatinosa Neurons in the Preparation of a Slice of Middle-Aged Rat Spinal Cord. Front Aging Neurosci 2021; 13:640265. [PMID: 33776744 PMCID: PMC7987937 DOI: 10.3389/fnagi.2021.640265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/08/2021] [Indexed: 11/29/2022] Open
Abstract
A patch-clamp recording in slices generated from the brain or the spinal cord has facilitated the exploration of neuronal circuits and the molecular mechanisms underlying neurological disorders. However, the rodents that are used to generate the spinal cord slices in previous studies involving a patch-clamp recording have been limited to those in the juvenile or adolescent stage. Here, we applied an N-methyl-D-glucamine HCl (NMDG-HCl) solution that enabled the patch-clamp recordings to be performed on the superficial dorsal horn neurons in the slices derived from middle-aged rats. The success rate of stable recordings from substantia gelatinosa (SG) neurons was 34.6% (90/260). When stimulated with long current pulses, 43.3% (39/90) of the neurons presented a tonic-firing pattern, which was considered to represent γ-aminobutyric acid-ergic (GABAergic) signals. Presumptive glutamatergic neurons presented 38.9% (35/90) delayed and 8.3% (7/90) single-spike patterns. The intrinsic membrane properties of both the neuron types were similar but delayed (glutamatergic) neurons appeared to be more excitable as indicated by the decreased latency and rheobase values of the action potential compared with those of tonic (GABAergic) neurons. Furthermore, the glutamatergic neurons were integrated, which receive more excitatory synaptic transmission. We demonstrated that the NMDG-HCl cutting solution could be used to prepare the spinal cord slices of middle-aged rodents for the patch-clamp recording. In combination with other techniques, this preparation method might permit the further study of the functions of the spinal cord in the pathological processes that occur in aging-associated diseases.
Collapse
Affiliation(s)
- Yang Li
- Hubei Key Laboratory of Embryonic Stem Cell Research, Department of Anesthesiology, Institute of Anesthesiology & Pain (IAP), Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Shanchu Su
- Hubei Key Laboratory of Embryonic Stem Cell Research, Department of Anesthesiology, Institute of Anesthesiology & Pain (IAP), Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Jiaqi Yu
- Hubei Key Laboratory of Embryonic Stem Cell Research, Department of Anesthesiology, Institute of Anesthesiology & Pain (IAP), Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Minjing Peng
- Hubei Key Laboratory of Embryonic Stem Cell Research, Department of Anesthesiology, Institute of Anesthesiology & Pain (IAP), Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Shengjun Wan
- Hubei Key Laboratory of Embryonic Stem Cell Research, Department of Anesthesiology, Institute of Anesthesiology & Pain (IAP), Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Changbin Ke
- Hubei Key Laboratory of Embryonic Stem Cell Research, Department of Anesthesiology, Institute of Anesthesiology & Pain (IAP), Taihe Hospital, Hubei University of Medicine, Shiyan, China
| |
Collapse
|
18
|
Wang X, Lai Q, Zheng B, Ye L, Wen S, Yan Y, Yang B, Man MQ. Both Prevalence and Severity of Pruritus are Associated with Age in Chinese Patients with Skin Diseases. Clin Cosmet Investig Dermatol 2021; 14:217-223. [PMID: 33692631 PMCID: PMC7939505 DOI: 10.2147/ccid.s300458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 02/12/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Although the characteristics of pruritus in some skin diseases are documented, characteristics of pruritus related to gender-, age-, and skin disorder have not yet been well defined. OBJECTIVE To characterize dermatosis-associated pruritus in Chinese patients. METHODS A cross-sectional study was carried out in a single center. The intensity of pruritus was evaluated using a 0-10 visual analog scale (VAS). Skin disorders were diagnosed by dermatologists. The prevalence and intensity of pruritus were compared among skin disorders, and between males and females. RESULTS Valid questionnaires were obtained from 1,246 female and 864 male patients. Patients with acne, eczematous dermatitis, and urticaria accounted for 18%, 17%, and 14%, respectively. Both the prevalence and severity of pruritus varied greatly with skin disorders (p<0.0001). Patients with either urticaria or eczematous dermatitis displayed a higher prevalence of pruritus (92% and 82%, respectively), while subjects with urticaria exhibited the highest VAS in comparison to those with other skin disorders (p<0.05 to p<0.001 vs the others). Moreover, both the prevalence and severity of pruritus were positively associated with age in both males and females (p<0.0001). Furthermore, 60 out of 77 patients (78%) with topical glucocorticoid-induced dermatitis experienced pruritus, with a VAS of 2.03±0.21. Finally, a lower VAS was found in subjects with oily skin than those with either dry or normal skin. CONCLUSION The prevalence and severity of pruritus vary with skin disorders, skin type, age, and gender in Chinese patients.
Collapse
Affiliation(s)
- Xiaohua Wang
- Dermatology Hospital, Southern Medical University, Guangdong, 510091, People’s Republic of China
| | - Qingsong Lai
- Center for Chronic Disease Prevention and Control of Puning City, Puning, Guangdong, 515300, People’s Republic of China
| | - Baoqing Zheng
- Dermatology Hospital, Southern Medical University, Guangdong, 510091, People’s Republic of China
| | - Li Ye
- Dermatology Hospital, Southern Medical University, Guangdong, 510091, People’s Republic of China
| | - Si Wen
- Dermatology Hospital, Southern Medical University, Guangdong, 510091, People’s Republic of China
| | - Yunling Yan
- Dermatology Hospital, Southern Medical University, Guangdong, 510091, People’s Republic of China
| | - Bin Yang
- Dermatology Hospital, Southern Medical University, Guangdong, 510091, People’s Republic of China
| | - Mao-Qiang Man
- Dermatology Hospital, Southern Medical University, Guangdong, 510091, People’s Republic of China
| |
Collapse
|
19
|
Wang Z, Jiang C, Yao H, Chen O, Rahman S, Gu Y, Zhao J, Huh Y, Ji RR. Central opioid receptors mediate morphine-induced itch and chronic itch via disinhibition. Brain 2021; 144:665-681. [PMID: 33367648 DOI: 10.1093/brain/awaa430] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 09/29/2020] [Accepted: 10/22/2020] [Indexed: 02/27/2024] Open
Abstract
Opioids such as morphine are mainstay treatments for clinical pain conditions. Itch is a common side effect of opioids, particularly as a result of epidural or intrathecal administration. Recent progress has advanced our understanding of itch circuits in the spinal cord. However, the mechanisms underlying opioid-induced itch are not fully understood, although an interaction between µ-opioid receptor (MOR) and gastrin-releasing peptide receptor (GRPR) in spinal GRPR-expressing neurons has been implicated. In this study we investigated the cellular mechanisms of intrathecal opioid-induced itch by conditional deletion of MOR-encoding Oprm1 in distinct populations of interneurons and sensory neurons. We found that intrathecal injection of the MOR agonists morphine or DAMGO elicited dose-dependent scratching as well as licking and biting, but this pruritus was totally abolished in mice with a specific Oprm1 deletion in Vgat+ neurons [Oprm1-Vgat (Slc32a1)]. Loss of MOR in somatostatin+ interneurons and TRPV1+ sensory neurons did not affect morphine-induced itch but impaired morphine-induced antinociception. In situ hybridization revealed Oprm1 expression in 30% of inhibitory and 20% of excitatory interneurons in the spinal dorsal horn. Whole-cell recordings from spinal cord slices showed that DAMGO induced outward currents in 9 of 19 Vgat+ interneurons examined. Morphine also inhibited action potentials in Vgat+ interneurons. Furthermore, morphine suppressed evoked inhibitory postsynaptic currents in postsynaptic Vgat- excitatory neurons, suggesting a mechanism of disinhibition by MOR agonists. Notably, morphine-elicited itch was suppressed by intrathecal administration of NPY and abolished by spinal ablation of GRPR+ neurons with intrathecal injection of bombesin-saporin, whereas intrathecal GRP-induced itch response remained intact in mice lacking Oprm1-Vgat. Intrathecal bombesin-saporin treatment reduced the number of GRPR+ neurons by 97% in the lumber spinal cord and 91% in the cervical spinal cord, without changing the number of Oprm1+ neurons. Additionally, chronic itch from DNFB-induced allergic contact dermatitis was decreased by Oprm1-Vgat deletion. Finally, naloxone, but not peripherally restricted naloxone methiodide, inhibited chronic itch in the DNFB model and the CTCL model, indicating a contribution of central MOR signalling to chronic itch. Our findings demonstrate that intrathecal morphine elicits itch via acting on MOR on spinal inhibitory interneurons, leading to disinhibition of the spinal itch circuit. Our data also provide mechanistic insights into the current treatment of chronic itch with opioid receptor antagonist such as naloxone.
Collapse
Affiliation(s)
- Zilong Wang
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Changyu Jiang
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Hongyu Yao
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ouyang Chen
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Sreya Rahman
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yun Gu
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Junli Zhao
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yul Huh
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| |
Collapse
|
20
|
Solinski HJ, Rukwied R. Electrically Evoked Itch in Human Subjects. Front Med (Lausanne) 2021; 7:627617. [PMID: 33553220 PMCID: PMC7855585 DOI: 10.3389/fmed.2020.627617] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 12/23/2020] [Indexed: 11/13/2022] Open
Abstract
Administration of chemicals (pruritogens) into the skin evokes itch based on signal transduction mechanisms that generate action potentials mainly in mechanically sensitive and insensitive primary afferent C-fibers (pruriceptors). These signals from peripheral neurons are processed in spinal and supra-spinal centers of the central nervous system and finally generate the sensation of itch. Compared to chemical stimulation, electrical activation of pruriceptors would allow for better temporal control and thereby a more direct functional assessment of their activation. Here, we review the electrical stimulation paradigms which were used to evoke itch in humans in the past. We further evaluate recent attempts to explore electrically induced itch in atopic dermatitis patients. Possible mechanisms underlying successful pruritus generation in chronic itch patients by transdermal slowly depolarizing electrical stimulation are discussed.
Collapse
Affiliation(s)
- Hans Jürgen Solinski
- Department of Experimental Pain Research, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Roman Rukwied
- Department of Experimental Pain Research, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| |
Collapse
|
21
|
Sheahan TD, Warwick CA, Fanien LG, Ross SE. The Neurokinin-1 Receptor is Expressed with Gastrin-Releasing Peptide Receptor in Spinal Interneurons and Modulates Itch. J Neurosci 2020; 40:8816-8830. [PMID: 33051347 PMCID: PMC7659450 DOI: 10.1523/jneurosci.1832-20.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/25/2020] [Accepted: 09/21/2020] [Indexed: 12/22/2022] Open
Abstract
The neurokinin-1 receptor (NK1R; encoded by Tacr1) is expressed in spinal dorsal horn neurons and has been suggested to mediate itch in rodents. However, previous studies relied heavily on neurotoxic ablation of NK1R spinal neurons, which limited further dissection of their function in spinal itch circuitry. To address this limitation, we leveraged a newly developed Tacr1CreER mouse line to characterize the role of NK1R spinal neurons in itch. We show that pharmacological activation of spinal NK1R and chemogenetic activation of Tacr1CreER spinal neurons increases itch behavior in male and female mice, whereas pharmacological inhibition of spinal NK1R suppresses itch behavior. We use fluorescence in situ hybridization (FISH) to characterize the endogenous expression of Tacr1 throughout the superficial and deeper dorsal horn (DDH), as well as the lateral spinal nucleus (LSN), of mouse and human spinal cord. Retrograde labeling studies in mice from the parabrachial nucleus (PBN) show that less than 20% of superficial Tacr1CreER dorsal horn neurons are spinal projection neurons, and thus the majority of Tacr1CreER are local interneurons. We then use a combination of in situ hybridization and ex vivo two-photon Ca2+ imaging of the mouse spinal cord to establish that NK1R and the gastrin-releasing peptide receptor (GRPR) are coexpressed within a subpopulation of excitatory superficial dorsal horn (SDH) neurons. These findings are the first to suggest a role for NK1R interneurons in itch and extend our understanding of the complexities of spinal itch circuitry.SIGNIFICANCE STATEMENT The spinal cord is a critical hub for processing somatosensory input, yet which spinal neurons process itch input and how itch signals are encoded within the spinal cord is not fully understood. We demonstrate neurokinin-1 receptor (NK1R) spinal neurons mediate itch behavior in mice and that the majority of NK1R spinal neurons are local interneurons. These NK1R neurons comprise a subset of gastrin-releasing peptide receptor (GRPR) interneurons and are thus positioned at the center of spinal itch transmission. We show NK1R mRNA expression in human spinal cord, underscoring the translational relevance of our findings in mice. This work is the first to suggest a role for NK1R interneurons in itch and extends our understanding of the complexities of spinal itch circuitry.
Collapse
Affiliation(s)
- Tayler D Sheahan
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh 15213, Pennsylvania
| | - Charles A Warwick
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh 15213, Pennsylvania
| | - Louis G Fanien
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh 15213, Pennsylvania
| | - Sarah E Ross
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh 15213, Pennsylvania
| |
Collapse
|
22
|
A spinal neural circuitry for converting touch to itch sensation. Nat Commun 2020; 11:5074. [PMID: 33033265 PMCID: PMC7545208 DOI: 10.1038/s41467-020-18895-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 09/17/2020] [Indexed: 12/14/2022] Open
Abstract
Touch and itch sensations are crucial for evoking defensive and emotional responses, and light tactile touch may induce unpleasant itch sensations (mechanical itch or alloknesis). The neural substrate for touch-to-itch conversion in the spinal cord remains elusive. We report that spinal interneurons expressing Tachykinin 2-Cre (Tac2Cre) receive direct Aβ low threshold mechanoreceptor (LTMR) input and form monosynaptic connections with GRPR neurons. Ablation or inhibition markedly reduces mechanical but not acute chemical itch nor noxious touch information. Chemogenetic inhibition of Tac2Cre neurons also displays pronounced deficit in chronic dry skin itch, a type of chemical itch in mice. Consistently, ablation of gastrin-releasing peptide receptor (GRPR) neurons, which are essential for transmitting chemical itch, also abolishes mechanical itch. Together, these results suggest that innocuous touch and chemical itch information converge on GRPR neurons and thus map an exquisite spinal circuitry hard-wired for converting innocuous touch to irritating itch.
Collapse
|
23
|
Abstract
Itch, in particular chronic forms, has been widely recognized as an important clinical problem, but much less is known about the mechanisms of itch in comparison with other sensory modalities such as pain. Recently, considerable progress has been made in dissecting the circuit mechanisms of itch at both the spinal and supraspinal levels. Major components of the spinal neural circuit underlying both chemical and mechanical itch have now been identified, along with the circuits relaying ascending transmission and the descending modulation of itch. In this review, we summarize the progress in elucidating the neural circuit mechanism of itch at spinal and supraspinal levels.
Collapse
Affiliation(s)
- Xiao-Jun 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, 200031, Shanghai, China
- University of Chinese Academy of Sciences, 19A Yu-quan Road, 100049, Beijing, 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, 200031, Shanghai, China.
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, 201210, Shanghai, China.
| |
Collapse
|
24
|
Wang X, Lai Q, Zheng B, Ye L, Wen S, Yan Y, Yang B, Man MQ. Prevalence and Severity of Dermatological Condition-Associated Skin Pain in the Chinese. J Pain Res 2020; 13:1201-1207. [PMID: 32581569 PMCID: PMC7266942 DOI: 10.2147/jpr.s245514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND/AIM Although the characteristics of cutaneous sensory symptoms in the general population have been documented, dermatological condition-associated skin pain has not been characterized yet. In the present study, we aimed to characterize dermatological condition-associated skin pain in the Chinese. SUBJECTS AND METHODS A questionnaire was given to outpatients to identify self-proclaimed skin pain at our dermatology clinic. The severity of skin pain was assessed using pain scale 0-10. Prevalence and pain severity were compared between males and females. RESULTS A total of 2144 patients, including 1254 females and 890 males aged 13-94 years, were included in this study. The overall prevalence of skin pain was 9.93% in this cohort. The prevalence of skin pain varied greatly with dermatological conditions (p<0.0001). Moreover, a higher prevalence of skin pain was observed in males than in females (p<0.05). Among the dermatological conditions reported, higher skin pain scales were found in subjects with either glucocorticoid-induced dermatitis (4.20 ± 0.73) or herpes zoster (4.00 ± 0.29). While the overall pain scales were comparable between males and females (2.38 ± 0.13 versus 2.68 ± 0.13), pain scales in patients with eczematous dermatitis were higher in females than in males (p<0.05). Furthermore, pain scales correlated positively with age. However, pain scales did not differ between subjects with versus without a family history of cutaneous sensory symptoms. These results demonstrate that the prevalence and severity of dermatological condition-associated skin pain vary with dermatological conditions and gender in the Chinese. CONCLUSION Patients with some dermatological conditions may experience skin pain. Although the pain is moderate, it can negatively impact the quality of patients' lives. Alleviation of skin pain should be considered when treating patients with certain dermatological conditions.
Collapse
Affiliation(s)
- Xiaohua Wang
- Dermatology Hospital, Southern Medical University, Guangdong510095, People’s Republic of China
| | - Qingsong Lai
- Puning City Chronic Disease Prevention and Control Center, Guangdong515300, People’s Republic of China
| | - Baoqing Zheng
- Dermatology Hospital, Southern Medical University, Guangdong510095, People’s Republic of China
| | - Li Ye
- Dermatology Hospital, Southern Medical University, Guangdong510095, People’s Republic of China
| | - Si Wen
- Dermatology Hospital, Southern Medical University, Guangdong510095, People’s Republic of China
| | - Yunling Yan
- Dermatology Hospital, Southern Medical University, Guangdong510095, People’s Republic of China
| | - Bin Yang
- Dermatology Hospital, Southern Medical University, Guangdong510095, People’s Republic of China
| | - Mao-Qiang Man
- Dermatology Hospital, Southern Medical University, Guangdong510095, People’s Republic of China
| |
Collapse
|