1
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Hui SE, Westlund KN. Role of HDAC5 Epigenetics in Chronic Craniofacial Neuropathic Pain. Int J Mol Sci 2024; 25:6889. [PMID: 38999998 PMCID: PMC11241576 DOI: 10.3390/ijms25136889] [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: 05/15/2024] [Revised: 06/08/2024] [Accepted: 06/16/2024] [Indexed: 07/14/2024] Open
Abstract
The information provided from the papers reviewed here about the role of epigenetics in chronic craniofacial neuropathic pain is critically important because epigenetic dysregulation during the development and maintenance of chronic neuropathic pain is not yet well characterized, particularly for craniofacial pain. We have noted that gene expression changes reported vary depending on the nerve injury model and the reported sample collection time point. At a truly chronic timepoint of 10 weeks in our model of chronic neuropathic pain, functional groupings of genes examined include those potentially contributing to anti-inflammation, nerve repair/regeneration, and nociception. Genes altered after treatment with the epigenetic modulator LMK235 are discussed. All of these differentials are key in working toward the development of diagnosis-targeted therapeutics and likely for the timing of when the treatment is provided. The emphasis on the relevance of time post-injury is reiterated here.
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Affiliation(s)
| | - Karin N. Westlund
- Department of Anesthesiology & Critical Care Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
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2
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Gradwell MA, Ozeri-Engelhard N, Eisdorfer JT, Laflamme OD, Gonzalez M, Upadhyay A, Medlock L, Shrier T, Patel KR, Aoki A, Gandhi M, Abbas-Zadeh G, Oputa O, Thackray JK, Ricci M, George A, Yusuf N, Keating J, Imtiaz Z, Alomary SA, Bohic M, Haas M, Hernandez Y, Prescott SA, Akay T, Abraira VE. Multimodal sensory control of motor performance by glycinergic interneurons of the mouse spinal cord deep dorsal horn. Neuron 2024; 112:1302-1327.e13. [PMID: 38452762 DOI: 10.1016/j.neuron.2024.01.027] [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: 06/13/2023] [Revised: 10/31/2023] [Accepted: 01/26/2024] [Indexed: 03/09/2024]
Abstract
Sensory feedback is integral for contextually appropriate motor output, yet the neural circuits responsible remain elusive. Here, we pinpoint the medial deep dorsal horn of the mouse spinal cord as a convergence point for proprioceptive and cutaneous input. Within this region, we identify a population of tonically active glycinergic inhibitory neurons expressing parvalbumin. Using anatomy and electrophysiology, we demonstrate that deep dorsal horn parvalbumin-expressing interneuron (dPV) activity is shaped by convergent proprioceptive, cutaneous, and descending input. Selectively targeting spinal dPVs, we reveal their widespread ipsilateral inhibition onto pre-motor and motor networks and demonstrate their role in gating sensory-evoked muscle activity using electromyography (EMG) recordings. dPV ablation altered limb kinematics and step-cycle timing during treadmill locomotion and reduced the transitions between sub-movements during spontaneous behavior. These findings reveal a circuit basis by which sensory convergence onto dorsal horn inhibitory neurons modulates motor output to facilitate smooth movement and context-appropriate transitions.
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Affiliation(s)
- Mark A Gradwell
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Nofar Ozeri-Engelhard
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Neuroscience PhD program, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Jaclyn T Eisdorfer
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Olivier D Laflamme
- Dalhousie PhD program, Dalhousie University, Halifax, NS, Canada; Department of Medical Neuroscience, Atlantic Mobility Action Project, Brain Repair Center, Dalhousie University, Halifax, NS, Canada
| | - Melissa Gonzalez
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Department of Biomedical Engineering, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Aman Upadhyay
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Neuroscience PhD program, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Laura Medlock
- Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, ON, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Tara Shrier
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Komal R Patel
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Adin Aoki
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Melissa Gandhi
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Gloria Abbas-Zadeh
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Olisemaka Oputa
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Joshua K Thackray
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Human Genetics Institute of New Jersey, Rutgers University, The State University of New Jersey, Piscataway, NJ, USA; Tourette International Collaborative Genetics Study (TIC Genetics)
| | - Matthew Ricci
- School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Arlene George
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Nusrath Yusuf
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Neuroscience PhD program, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Jessica Keating
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Zarghona Imtiaz
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Simona A Alomary
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Manon Bohic
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Michael Haas
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Yurdiana Hernandez
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Steven A Prescott
- Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, ON, Canada; Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Turgay Akay
- Department of Medical Neuroscience, Atlantic Mobility Action Project, Brain Repair Center, Dalhousie University, Halifax, NS, Canada
| | - Victoria E Abraira
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA.
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3
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Qin QR, Xu ZQ, Liu TT, Li XM, Qiu CY, Hu WP. CCK-8 enhances acid-sensing ion channel currents in rat primary sensory neurons. Neuropharmacology 2023; 241:109739. [PMID: 37820935 DOI: 10.1016/j.neuropharm.2023.109739] [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: 08/09/2023] [Revised: 09/07/2023] [Accepted: 09/28/2023] [Indexed: 10/13/2023]
Abstract
Cholecystokinin (CCK) is a peptide that has been implicated in pain modulation. Acid sensitive ion channels (ASICs) also play an important role in pain associated with tissue acidification. However, it is still unclear whether there is an interaction between CCK signaling and ASICs during pain process. Herein, we report that a functional link between them in rat dorsal root ganglion (DRG) neurons. Pretreatment with CCK-8 concentration-dependently increased acid-evoked ASIC currents. CCK-8 increased the maximum response of ASICs to acid, but did not changed their acid sensitivity. Enhancement of ASIC currents by CCK-8 was mediated by the stimulation of CCK2 receptor (CCK2R), rather than CCK1R. The enhancement of ASIC currents by CCK-8 was prevented by application of either G-protein inhibitor GDP-β-S or protein kinase C (PKC) inhibitor GF109203×, but not by protein kinase A (PKA) inhibitor H-89 or JNK inhibitor SP600125. Moreover, CCK-8 increased the number of action potentials triggered by acid stimuli by activating CCK2R. Finally, CCK-8 dose-dependently exacerbated acid-induced nociceptive behavior in rats through local CCK2R. Together, these results indicated that CCK-8/CCK2R activation enhanced ASIC-mediated electrophysiological activity in DRG neurons and nociception in rats. The enhancement effect depended on G-proteins and intracellular PKC signaling rather than PKA and JNK signaling pathway. These findings provided that CCK-8/CCK2R is an important therapeutic target for ASIC-mediated pain.
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Affiliation(s)
- Qing-Rui Qin
- School of Pharmacy, School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China
| | - Zhong-Qing Xu
- School of Pharmacy, School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China
| | - Ting-Ting Liu
- School of Pharmacy, School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China
| | - Xue-Mei Li
- School of Pharmacy, School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China
| | - Chun-Yu Qiu
- School of Pharmacy, School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China.
| | - Wang-Ping Hu
- School of Pharmacy, School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China; Department of Physiology, Hubei College of Chinese Medicine, 87 Xueyuan Road, Jingzhou 434020, Hubei, PR China.
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4
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Quillet R, Gutierrez-Mecinas M, Polgár E, Dickie AC, Boyle KA, Watanabe M, Todd AJ. Synaptic circuits involving gastrin-releasing peptide receptor-expressing neurons in the dorsal horn of the mouse spinal cord. Front Mol Neurosci 2023; 16:1294994. [PMID: 38143564 PMCID: PMC10742631 DOI: 10.3389/fnmol.2023.1294994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/13/2023] [Indexed: 12/26/2023] Open
Abstract
The superficial dorsal horn (SDH) of the spinal cord contains a diverse array of neurons. The vast majority of these are interneurons, most of which are glutamatergic. These can be assigned to several populations, one of which is defined by expression of gastrin-releasing peptide receptor (GRPR). The GRPR cells are thought to be "tertiary pruritoceptors," conveying itch information to lamina I projection neurons of the anterolateral system (ALS). Surprisingly, we recently found that GRPR-expressing neurons belong to a morphological class known as vertical cells, which are believed to transmit nociceptive information to lamina I ALS cells. Little is currently known about synaptic circuits engaged by the GRPR cells. Here we combine viral-mediated expression of PSD95-tagRFP fusion protein with super-resolution microscopy to reveal sources of excitatory input to GRPR cells. We find that they receive a relatively sparse input from peptidergic and non-peptidergic nociceptors in SDH, and a limited input from A- and C-low threshold mechanoreceptors on their ventral dendrites. They receive synapses from several excitatory interneuron populations, including those defined by expression of substance P, neuropeptide FF, cholecystokinin, neurokinin B, and neurotensin. We investigated downstream targets of GRPR cells by chemogenetically exciting them and identifying Fos-positive (activated) cells. In addition to lamina I projection neurons, many ALS cells in lateral lamina V and the lateral spinal nucleus were Fos-positive, suggesting that GRPR-expressing cells target a broader population of projection neurons than was previously recognised. Our findings indicate that GRPR cells receive a diverse synaptic input from various types of primary afferent and excitatory interneuron, and that they can activate ALS cells in both superficial and deep regions of the dorsal horn.
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Affiliation(s)
- Raphaëlle Quillet
- School of Psychology and Neuroscience, University of Glasgow, Glasgow, United Kingdom
| | | | - Erika Polgár
- School of Psychology and Neuroscience, University of Glasgow, Glasgow, United Kingdom
| | - Allen C. Dickie
- School of Psychology and Neuroscience, University of Glasgow, Glasgow, United Kingdom
| | - Kieran A. Boyle
- School of Psychology and Neuroscience, University of Glasgow, Glasgow, United Kingdom
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Andrew J. Todd
- School of Psychology and Neuroscience, University of Glasgow, Glasgow, United Kingdom
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5
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Veshchitskii A, Merkulyeva N. Calcium-binding protein parvalbumin in the spinal cord and dorsal root ganglia. Neurochem Int 2023; 171:105634. [PMID: 37967669 DOI: 10.1016/j.neuint.2023.105634] [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: 05/13/2023] [Revised: 09/20/2023] [Accepted: 10/26/2023] [Indexed: 11/17/2023]
Abstract
Parvalbumin is one of the calcium-binding proteins. In the spinal cord, it is mainly expressed in inhibitory neurons; in the dorsal root ganglia, it is expressed in proprioceptive neurons. In contrast to in the brain, weak systematization of parvalbumin-expressing neurons occurs in the spinal cord. The aim of this paper is to provide a systematic review of parvalbumin-expressing neuronal populations throughout the spinal cord and the dorsal root ganglia of mammals, regarding their mapping, co-expression with some functional markers. The data reviewed are mostly concerning rodentia species because they are predominantly presented in literature.
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Affiliation(s)
- Aleksandr Veshchitskii
- Neuromorphology Lab, Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
| | - Natalia Merkulyeva
- Neuromorphology Lab, Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia.
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6
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Nelson TS, Allen HN, Basu P, Prasoon P, Nguyen E, Arokiaraj CM, Santos DF, Seal RP, Ross SE, Todd AJ, Taylor BK. Alleviation of neuropathic pain with neuropeptide Y requires spinal Npy1r interneurons that coexpress Grp. JCI Insight 2023; 8:e169554. [PMID: 37824208 PMCID: PMC10721324 DOI: 10.1172/jci.insight.169554] [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: 02/07/2023] [Accepted: 10/04/2023] [Indexed: 10/14/2023] Open
Abstract
Neuropeptide Y targets the Y1 receptor (Y1) in the spinal dorsal horn (DH) to produce endogenous and exogenous analgesia. DH interneurons that express Y1 (Y1-INs; encoded by Npy1r) are necessary and sufficient for neuropathic hypersensitivity after peripheral nerve injury. However, as Y1-INs are heterogenous in composition in terms of morphology, neurophysiological characteristics, and gene expression, we hypothesized that a more precisely defined subpopulation mediates neuropathic hypersensitivity. Using fluorescence in situ hybridization, we found that Y1-INs segregate into 3 largely nonoverlapping subpopulations defined by the coexpression of Npy1r with gastrin-releasing peptide (Grp/Npy1r), neuropeptide FF (Npff/Npy1r), and cholecystokinin (Cck/Npy1r) in the superficial DH of mice, nonhuman primates, and humans. Next, we analyzed the functional significance of Grp/Npy1r, Npff/Npy1r, and Cck/Npy1r INs to neuropathic pain using a mouse model of peripheral nerve injury. We found that chemogenetic inhibition of Npff/Npy1r-INs did not change the behavioral signs of neuropathic pain. Further, inhibition of Y1-INs with an intrathecal Y1 agonist, [Leu31, Pro34]-NPY, reduced neuropathic hypersensitivity in mice with conditional deletion of Npy1r from CCK-INs and NPFF-INs but not from GRP-INs. We conclude that Grp/Npy1r-INs are conserved in higher order mammalian species and represent a promising and precise pharmacotherapeutic target for the treatment of neuropathic pain.
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Affiliation(s)
- Tyler S. Nelson
- Department of Anesthesiology and Perioperative Medicine
- Pittsburgh Project to end Opioid Misuse
- Center for Neuroscience
| | - Heather N. Allen
- Department of Anesthesiology and Perioperative Medicine
- Pittsburgh Project to end Opioid Misuse
- Pittsburgh Center for Pain Research, and
| | - Paramita Basu
- Department of Anesthesiology and Perioperative Medicine
- Pittsburgh Project to end Opioid Misuse
- Pittsburgh Center for Pain Research, and
| | - Pranav Prasoon
- Department of Anesthesiology and Perioperative Medicine
- Pittsburgh Project to end Opioid Misuse
- Pittsburgh Center for Pain Research, and
| | - Eileen Nguyen
- Center for Neuroscience
- Pittsburgh Center for Pain Research, and
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Cynthia M. Arokiaraj
- Center for Neuroscience
- Pittsburgh Center for Pain Research, and
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Diogo F.S. Santos
- Department of Anesthesiology and Perioperative Medicine
- Pittsburgh Project to end Opioid Misuse
- Pittsburgh Center for Pain Research, and
| | - Rebecca P. Seal
- Center for Neuroscience
- Pittsburgh Center for Pain Research, and
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarah E. Ross
- Center for Neuroscience
- Pittsburgh Center for Pain Research, and
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Andrew J. Todd
- Spinal Cord Group, School of Psychology and Neuroscience, University of Glasgow, Glasgow, United Kingdom
| | - Bradley K. Taylor
- Department of Anesthesiology and Perioperative Medicine
- Pittsburgh Project to end Opioid Misuse
- Center for Neuroscience
- Pittsburgh Center for Pain Research, and
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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7
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Kunamneni A, Montera MA, Durvasula R, Alles SRA, Goyal S, Westlund KN. Rapid Generation and Molecular Docking Analysis of Single-Chain Fragment Variable (scFv) Antibody Selected by Ribosome Display Targeting Cholecystokinin B Receptor (CCK-BR) for Reduction of Chronic Neuropathic Pain. Int J Mol Sci 2023; 24:11035. [PMID: 37446213 DOI: 10.3390/ijms241311035] [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: 05/02/2023] [Revised: 06/06/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023] Open
Abstract
A robust cell-free platform technology, ribosome display in combination with cloning, expression, and purification was utilized to develop single chain Fragment variable (scFv) antibody variants as pain therapy directed at the mouse cholecystokinin B (CCK-B) receptor. Three effective CCK-B peptide-specific scFvs were generated through ribosomal display technology. Soluble expression and ELISA analysis showed that one antibody, scFv77-2 had the highest binding and could be purified from bacterial cells in large quantities. Octet measurements further revealed that the CCK-B scFv77-2 antibody had binding kinetics of KD = 1.794 × 10-8 M. Molecular modeling and docking analyses suggested that the scFv77-2 antibody shaped a proper cavity to embed the whole CCK-B peptide molecule and that a steady-state complex was formed relying on intermolecular forces, including hydrogen bonding, electrostatic force, and hydrophobic interactions. Thus, the scFv antibody can be applied for mechanistic intermolecular interactions and functional in vivo studies of CCK-BR. The high affinity scFv77-2 antibody showed good efficacy with binding to CCK-BR tested in a chronic pain model. In vivo studies validated the efficacy of the CCK-B receptor (CCK-BR) scFv77-2 antibody as a potential therapy for chronic trigeminal nerve injury-induced pain. Mice were given a single dose of the CCK-B receptor (CCK-BR) scFv antibody 3 weeks after induction of a chronic trigeminal neuropathic pain model, during the transition from acute to chronic pain. The long-term effectiveness for the reduction of mechanical hypersensitivity was evident, persisting for months. The anxiety- and depression-related behaviors typically accompanying persisting hypersensitivity subsequently never developed in the mice given CCK-BR scFv. The effectiveness of the antibody is the basis for further development of the lead CCK-BR scFv as a promising non-opioid therapeutic for chronic pain and the long-term reduction of chronic pain- and anxiety-related behaviors.
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Affiliation(s)
- Adinarayana Kunamneni
- Department of Internal Medicine, Mayo Clinic, Jacksonville, FL 32224-1865, USA
- Department of Medicine, Loyola University Medical Center, Maywood, IL 60153-3328, USA
| | - Marena A Montera
- Department of Anesthesiology & Critical Care Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Ravi Durvasula
- Department of Internal Medicine, Mayo Clinic, Jacksonville, FL 32224-1865, USA
- Department of Medicine, Loyola University Medical Center, Maywood, IL 60153-3328, USA
| | - Sascha R A Alles
- Department of Anesthesiology & Critical Care Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Sachin Goyal
- Department of Anesthesiology & Critical Care Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131-0001, USA
| | - Karin N Westlund
- Department of Anesthesiology & Critical Care Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131-0001, USA
- Biomedical Laboratory Research & Development (121F), New Mexico VA Health Care System, Albuquerque, NM 87108-5153, USA
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8
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Frezel N, Ranucci M, Foster E, Wende H, Pelczar P, Mendes R, Ganley RP, Werynska K, d'Aquin S, Beccarini C, Birchmeier C, Zeilhofer HU, Wildner H. c-Maf-positive spinal cord neurons are critical elements of a dorsal horn circuit for mechanical hypersensitivity in neuropathy. Cell Rep 2023; 42:112295. [PMID: 36947543 PMCID: PMC10157139 DOI: 10.1016/j.celrep.2023.112295] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/02/2023] [Accepted: 03/06/2023] [Indexed: 03/23/2023] Open
Abstract
Corticospinal tract (CST) neurons innervate the deep spinal dorsal horn to sustain chronic neuropathic pain. The majority of neurons targeted by the CST are interneurons expressing the transcription factor c-Maf. Here, we used intersectional genetics to decipher the function of these neurons in dorsal horn sensory circuits. We find that excitatory c-Maf (c-MafEX) neurons receive sensory input mainly from myelinated fibers and target deep dorsal horn parabrachial projection neurons and superficial dorsal horn neurons, thereby connecting non-nociceptive input to nociceptive output structures. Silencing c-MafEX neurons has little effect in healthy mice but alleviates mechanical hypersensitivity in neuropathic mice. c-MafEX neurons also receive input from inhibitory c-Maf and parvalbumin neurons, and compromising inhibition by these neurons caused mechanical hypersensitivity and spontaneous aversive behaviors reminiscent of c-MafEX neuron activation. Our study identifies c-MafEX neurons as normally silent second-order nociceptors that become engaged in pathological pain signaling upon loss of inhibitory control.
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Affiliation(s)
- Noémie Frezel
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland
| | - Matteo Ranucci
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland
| | - Edmund Foster
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland
| | | | - Pawel Pelczar
- Center for Transgenic Models (CTM), University of Basel, 4001 Basel, Switzerland
| | - Raquel Mendes
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland
| | - Robert P Ganley
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland
| | - Karolina Werynska
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland
| | - Simon d'Aquin
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland
| | - Camilla Beccarini
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland
| | | | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland; Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zürich, 8092 Zürich, Switzerland.
| | - Hendrik Wildner
- Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland.
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9
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Quillet R, Dickie AC, Polgár E, Gutierrez-Mecinas M, Bell AM, Goffin L, Watanabe M, Todd AJ. Characterisation of NPFF-expressing neurons in the superficial dorsal horn of the mouse spinal cord. Sci Rep 2023; 13:5891. [PMID: 37041197 PMCID: PMC10090074 DOI: 10.1038/s41598-023-32720-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 03/31/2023] [Indexed: 04/13/2023] Open
Abstract
Excitatory interneurons in the superficial dorsal horn (SDH) are heterogeneous, and include a class known as vertical cells, which convey information to lamina I projection neurons. We recently used pro-NPFF antibody to reveal a discrete population of excitatory interneurons that express neuropeptide FF (NPFF). Here, we generated a new mouse line (NPFFCre) in which Cre is knocked into the Npff locus, and used Cre-dependent viruses and reporter mice to characterise NPFF cell properties. Both viral and reporter strategies labelled many cells in the SDH, and captured most pro-NPFF-immunoreactive neurons (75-80%). However, the majority of labelled cells lacked pro-NPFF, and we found considerable overlap with a population of neurons that express the gastrin-releasing peptide receptor (GRPR). Morphological reconstruction revealed that most pro-NPFF-containing neurons were vertical cells, but these differed from GRPR neurons (which are also vertical cells) in having a far higher dendritic spine density. Electrophysiological recording showed that NPFF cells also differed from GRPR cells in having a higher frequency of miniature EPSCs, being more electrically excitable and responding to a NPY Y1 receptor agonist. Together, these findings indicate that there are at least two distinct classes of vertical cells, which may have differing roles in somatosensory processing.
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Affiliation(s)
- Raphaëlle Quillet
- School of Psychology and Neuroscience, Sir James Black Building, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Allen C Dickie
- School of Psychology and Neuroscience, Sir James Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Erika Polgár
- School of Psychology and Neuroscience, Sir James Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Maria Gutierrez-Mecinas
- School of Psychology and Neuroscience, Sir James Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andrew M Bell
- School of Psychology and Neuroscience, Sir James Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Luca Goffin
- School of Psychology and Neuroscience, Sir James Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo, 060-8638, Japan
| | - Andrew J Todd
- School of Psychology and Neuroscience, Sir James Black Building, University of Glasgow, Glasgow, G12 8QQ, UK.
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10
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Gutierrez-Mecinas M, Kókai É, Polgár E, Quillet R, Titterton HF, Weir GA, Watanabe M, Todd AJ. Antibodies Against the Gastrin-releasing Peptide Precursor Pro-Gastrin-releasing Peptide Reveal Its Expression in the Mouse Spinal Dorsal Horn. Neuroscience 2023; 510:60-71. [PMID: 36581131 DOI: 10.1016/j.neuroscience.2022.12.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/24/2022] [Accepted: 12/20/2022] [Indexed: 12/27/2022]
Abstract
Gastrin-releasing peptide (GRP) in the spinal dorsal horn acts on the GRP receptor, and this signalling mechanism has been strongly implicated in itch. However, the source of GRP in the dorsal horn is not fully understood. For example, the BAC transgenic mouse line GRP::GFP only captures around 25% of GRP-expressing cells, and Grp mRNA is found in several types of excitatory interneuron. A major limitation in attempts to identify GRP-expressing neurons has been that antibodies against GRP cross-react with other neuropeptides, including some that are expressed by primary afferents. Here we have developed two antibodies raised against different parts of the precursor protein, pro-GRP. We show that labelling is specific, and that the antibodies do not cross-react with neuropeptides in primary afferents. Immunoreactivity was strongest in the superficial laminae, and the two antibodies labelled identical structures, including glutamatergic axons and cell bodies. The pattern of pro-GRP-immunoreactivity varied among different neurochemical classes of excitatory interneuron. Cell bodies and axons of all GRP-GFP cells were labelled, confirming reliability of the antibodies. Among the other populations, we found the highest degree of co-expression (>50%) in axons of NPFF-expressing cells, while this was somewhat lower (10-20%) in cells that expressed substance P and NKB, and much lower (<10%) in other classes. Our findings show that these antibodies reliably detect GRP-expressing neurons and axons, and that in addition to the GRP-GFP cells, excitatory interneurons expressing NPFF or substance P are likely to be the main source of GRP in the spinal dorsal horn.
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Affiliation(s)
- Maria Gutierrez-Mecinas
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Éva Kókai
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Erika Polgár
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Raphaëlle Quillet
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Heather F Titterton
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Greg A Weir
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo 060-8638, Japan
| | - Andrew J Todd
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
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11
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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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Hiraga SI, Itokazu T, Nishibe M, Yamashita T. Neuroplasticity related to chronic pain and its modulation by microglia. Inflamm Regen 2022; 42:15. [PMID: 35501933 PMCID: PMC9063368 DOI: 10.1186/s41232-022-00199-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 02/19/2022] [Indexed: 01/03/2023] Open
Abstract
Neuropathic pain is often chronic and can persist after overt tissue damage heals, suggesting that its underlying mechanism involves the alteration of neuronal function. Such an alteration can be a direct consequence of nerve damage or a result of neuroplasticity secondary to the damage to tissues or to neurons. Recent studies have shown that neuroplasticity is linked to causing neuropathic pain in response to nerve damage, which may occur adjacent to or remotely from the site of injury. Furthermore, studies have revealed that neuroplasticity relevant to chronic pain is modulated by microglia, resident immune cells of the central nervous system (CNS). Microglia may directly contribute to synaptic remodeling and altering pain circuits, or indirectly contribute to neuroplasticity through property changes, including the secretion of growth factors. We herein highlight the mechanisms underlying neuroplasticity that occur in the somatosensory circuit of the spinal dorsal horn, thalamus, and cortex associated with chronic pain following injury to the peripheral nervous system (PNS) or CNS. We also discuss the dynamic functions of microglia in shaping neuroplasticity related to chronic pain. We suggest further understanding of post-injury ectopic plasticity in the somatosensory circuits may shed light on the differential mechanisms underlying nociceptive, neuropathic, and nociplastic-type pain. While one of the prominent roles played by microglia appears to be the modulation of post-injury neuroplasticity. Therefore, future molecular- or genetics-based studies that address microglia-mediated post-injury neuroplasticity may contribute to the development of novel therapies for chronic pain.
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Affiliation(s)
- Shin-Ichiro Hiraga
- Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.,Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Takahide Itokazu
- Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan. .,Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
| | - Mariko Nishibe
- Center for Strategic Innovative Dentistry, Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan
| | - Toshihide Yamashita
- Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan. .,Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan. .,WPI Immunology Frontier Research Center, Osaka, Japan. .,Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.
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Gradwell MA, Boyle KA, Browne TJ, Bell AM, Leonardo J, Peralta Reyes FS, Dickie AC, Smith KM, Callister RJ, Dayas CV, Hughes DI, Graham BA. Diversity of inhibitory and excitatory parvalbumin interneuron circuits in the dorsal horn. Pain 2022; 163:e432-e452. [PMID: 34326298 PMCID: PMC8832545 DOI: 10.1097/j.pain.0000000000002422] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 12/03/2022]
Abstract
ABSTRACT Parvalbumin-expressing interneurons (PVINs) in the spinal dorsal horn are found primarily in laminae II inner and III. Inhibitory PVINs play an important role in segregating innocuous tactile input from pain-processing circuits through presynaptic inhibition of myelinated low-threshold mechanoreceptors and postsynaptic inhibition of distinct spinal circuits. By comparison, relatively little is known of the role of excitatory PVINs (ePVINs) in sensory processing. Here, we use neuroanatomical and optogenetic approaches to show that ePVINs comprise a larger proportion of the PVIN population than previously reported and that both ePVIN and inhibitory PVIN populations form synaptic connections among (and between) themselves. We find that these cells contribute to neuronal networks that influence activity within several functionally distinct circuits and that aberrant activity of ePVINs under pathological conditions is well placed to contribute to the development of mechanical hypersensitivity.
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Affiliation(s)
- Mark A. Gradwell
- Faculty of Health, School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, Australia
- Hunter Medical Research Institute (HMRI), New Lambton Heights, New South Wales, Australia
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, United States
- W.M. Keck Center for Collaborative Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, United States
| | - Kieran A. Boyle
- Institute of Neuroscience Psychology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Tyler J. Browne
- Faculty of Health, School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, Australia
- Hunter Medical Research Institute (HMRI), New Lambton Heights, New South Wales, Australia
| | - Andrew M. Bell
- Institute of Neuroscience Psychology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Jacklyn Leonardo
- Institute of Neuroscience Psychology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Fernanda S. Peralta Reyes
- Institute of Neuroscience Psychology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Allen C. Dickie
- Institute of Neuroscience Psychology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kelly M. Smith
- Faculty of Health, School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, Australia
- Hunter Medical Research Institute (HMRI), New Lambton Heights, New South Wales, Australia
- Department of Neurobiology and the Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Robert J. Callister
- Faculty of Health, School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, Australia
- Hunter Medical Research Institute (HMRI), New Lambton Heights, New South Wales, Australia
| | - Christopher V. Dayas
- Faculty of Health, School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, Australia
- Hunter Medical Research Institute (HMRI), New Lambton Heights, New South Wales, Australia
| | - David I. Hughes
- Institute of Neuroscience Psychology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Brett A. Graham
- Faculty of Health, School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, Australia
- Hunter Medical Research Institute (HMRI), New Lambton Heights, New South Wales, Australia
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14
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CCK2 receptors in chronic pain. NEUROBIOLOGY OF PAIN 2022; 11:100092. [PMID: 35571964 PMCID: PMC9097710 DOI: 10.1016/j.ynpai.2022.100092] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/22/2022] [Accepted: 05/02/2022] [Indexed: 11/21/2022]
Abstract
CCK2R is a historic target for pain management that has shown limited success. We review CCK2Rs and their role in peripheral and central circuits in chronic pain. We discuss the interactions between CCK2Rs and opioids. We highlight recent drug discovery efforts targeting CCK2R for chronic pain.
The cholecystokinin receptor system, specifically cholecystokinin 2 receptor (CCK2R) is a historic target for pain management that has shown limited success. However, new approaches to target CCK2R have incited fresh enthusiasm for this target. In this mini-review, we discuss what is known about CCK2R in peripheral and central circuits under naïve physiological conditions and under conditions of chronic pain, the interactions of CCK2Rs with opioids and briefly, recent efforts to develop new treatments targeting CCK2R for chronic pain.
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Duan LL, Qiu XY, Wei SQ, Su HY, Bai FR, Traub RJ, Zhou Q, Cao DY. Spinal CCK contributes to somatic hyperalgesia induced by orofacial inflammation combined with stress in adult female rats. Eur J Pharmacol 2021; 913:174619. [PMID: 34748768 DOI: 10.1016/j.ejphar.2021.174619] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 11/01/2021] [Accepted: 11/03/2021] [Indexed: 11/28/2022]
Abstract
In some chronic primary pain conditions such as temporomandibular disorder (TMD) and fibromyalgia syndrome (FMS), mild or chronic stress enhances pain. TMD and FMS often occur together, but the underlying mechanisms are unclear. The purpose of this study was to investigate the role of cholecystokinin (CCK) in the spinal cord in somatic hyperalgesia induced by orofacial inflammation combined with stress. Somatic hyperalgesia was detected by the thermal withdrawal latency and mechanical withdrawal threshold. The expression of CCK1 receptors, CCK2 receptors, ERK1/2 and p-ERK1/2 in the spinal cord was examined by Western blot. After the stimulation of orofacial inflammation combined with 3 day forced swim, the expression of CCK2 receptors and p-ERK1/2 protein in the L4-L5 spinal dorsal horn increased significantly, while the expression of CCK1 receptors and ERK1/2 protein remained unchanged. Intrathecal injection of the CCK2 receptor antagonist YM-022 or mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor PD98059 blocked somatic hyperalgesia induced by orofacial inflammation combined with stress. Intrathecal administration of the MEK inhibitor blocked somatic sensitization caused by the CCK receptor agonist CCK8. The CCK2 receptor antagonist YM-022 significantly reduced the expression of p-ERK1/2. These data indicate that upregulation of CCK2 receptors through the MAPK pathway contributes to somatic hyperalgesia in this comorbid pain model. Thus, CCK2 receptors and MAPK pathway may be potential targets for the treatment of TMD comorbid with FMS.
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Affiliation(s)
- Lu-Lu Duan
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University College of Stomatology, 98 West 5th Road, Xi'an, Shaanxi, 710004, China; Department of Implant Dentistry, Xi'an Jiaotong University College of Stomatology, 98 West 5th Road, Xi'an, Shaanxi, 710004, China
| | - Xin-Yi Qiu
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University College of Stomatology, 98 West 5th Road, Xi'an, Shaanxi, 710004, China
| | - Si-Qi Wei
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University College of Stomatology, 98 West 5th Road, Xi'an, Shaanxi, 710004, China
| | - Han-Yu Su
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University College of Stomatology, 98 West 5th Road, Xi'an, Shaanxi, 710004, China
| | - Fu-Rong Bai
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University College of Stomatology, 98 West 5th Road, Xi'an, Shaanxi, 710004, China
| | - Richard J Traub
- Department of Neural and Pain Sciences, UM Center to Advance Chronic Pain Research, University of Maryland School of Dentistry, Baltimore MD, 21201, USA
| | - Qin Zhou
- Department of Implant Dentistry, Xi'an Jiaotong University College of Stomatology, 98 West 5th Road, Xi'an, Shaanxi, 710004, China.
| | - Dong-Yuan Cao
- Department of Implant Dentistry, Xi'an Jiaotong University College of Stomatology, 98 West 5th Road, Xi'an, Shaanxi, 710004, China.
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16
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Javed H, Rehmathulla S, Tariq S, Ali MA, Emerald BS, Shehab S. Co-localization of nociceptive markers in the lumbar dorsal root ganglion and spinal cord of dromedary camel. J Comp Neurol 2021; 529:3710-3725. [PMID: 34468017 DOI: 10.1002/cne.25240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/19/2021] [Accepted: 08/26/2021] [Indexed: 11/12/2022]
Abstract
Nociceptive markers in mice have been identified in two distinct peptidergic and nonpeptidergic neurons in the dorsal root ganglion (DRG) and distributed in different laminae of the dorsal horn of the spinal cord. Recently, however, a study in humans showed a significant overlapping in these two populations. In this study, we investigated the distribution of various nociceptive markers in the lumbar DRG and spinal cord of the dromedary camel. Immunohistochemical data showed a remarkable percentage of total neurons in the DRG expressed IB4 binding (54.5%), calcitonin gene-related peptide (CGRP; 49.5%), transient receptor potential vanilloid 1 (TRPV1; 48.2%), and nitric oxide synthase (NOS; 30.6%). The co-localization data showed that 89.6% and 74.0% of CGRP- and TRPV1-labeled neurons, respectively, were IB4 positive. In addition, 61.6% and 84.2% of TRPV1- and NOS-immunoreactive neurons, respectively, were also co-localized with CGRP. The distribution of IB4, CGRP, TRPV1, substance P, and NOS immunoreactivities in the spinal cord were observed in lamina I and outer lamina II (IIo). Quantitative data showed that 82.4% of IB4-positive nerve terminals in laminae I and IIo were co-localized with CGRP, and 86.0% of CGRP-labeled terminals were co-localized with IB4. Similarly, 85.1% of NOS-labeled nerve terminals were co-localized with CGRP. No neuropeptide Y (NPY) or cholecystokinin (CCK) immunoreactivities were detected in the DRG, and no co-localization between IB4, NPY, and CCK were observed in the spinal cord. Our results demonstrate marked convergence of nociceptive markers in the primary afferent neurons in camels, which is similar to humans rather than the mouse. The data also emphasizes the importance of interspecies differences when selecting ideal animal models for studying nociception and treating chronic pain.
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Affiliation(s)
- Hayate Javed
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Sumisha Rehmathulla
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Saeed Tariq
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Mahmoud A Ali
- Department of Pharmacology, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Bright Starling Emerald
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Safa Shehab
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, UAE
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17
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Westlund K, Montera M, Goins A, Alles S, Afaghpour-Becklund M, Bartel R, Durvasula R, Kunamneni A. Single-chain Fragment variable antibody targeting cholecystokinin-B receptor for pain reduction. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2021; 10:100067. [PMID: 34458647 PMCID: PMC8378781 DOI: 10.1016/j.ynpai.2021.100067] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/09/2021] [Accepted: 07/09/2021] [Indexed: 05/13/2023]
Abstract
The cholecystokinin B receptor and its neuropeptide ligand are upregulated in chronic neuropathic pain models. Single-chain Fragment variable antibodies were generated as preferred non-opioid targeting therapy blocking the cholecystokinin B receptor to inhibit chronic neuropathic pain models in vivo and in vitro. Engineered antibodies of this type feature binding activity similar to monoclonal antibodies but with stronger affinity and increased tissue penetrability due to their smaller size. More importantly, single-chain Fragment variable antibodies have promising biotherapeutic applications for both nervous and immune systems, now recognized as interactive in chronic pain. A mouse single-chain Fragment variable antibody library recognizing a fifteen amino acid extracellular peptide fragment of the cholecystokinin B receptor was generated from immunized spleens. Ribosome display, a powerful cell-free technology, was applied for recombinant antibody selection. Antibodies with higher affinity, stability, solubility, and binding specificity for cholecystokinin B not A receptor were selected and optimized for in vivo and in vitro efficacy. A single dose of the lead candidate reduced mechanical and cold hypersensitivity in two rodent models of neuropathic pain for at least seven weeks. Continuing efficacy was evident with either intraperitoneal or intranasal dosing. Likewise, the lead single-chain Fragment variable antibody totally prevented development of anxiety- and depression-like behaviors and cognitive deficits typical in the models. Reduction of neuronal firing frequency was evident in trigeminal ganglia primary neuronal cultures treated in vitro with the cholecystokinin B receptor antibody. Immunofluorescent staining intensity in the trigeminal neuron primary cultures was significantly reduced incrementally after overnight binding with increasingly higher dilutions of the single-chain Fragment variable antibody. While it is reported that single-chain Fragment variable antibodies are removed systemically within 2-6 h, Western blot evidence indicates the His-tag marker remained after 7 weeks in the trigeminal ganglia and in the dorsolateral medulla, providing evidence of brain and ganglia penetrance known to be compromised in overactivated states. This project showcases the in vivo efficacy of our lead single-chain Fragment variable antibody indicating its potential for development as a non-opioid, non-addictive therapeutic intervention for chronic pain. Importantly, studies by others have indicated treatments with cholecystokinin B receptor antagonists suppress maintenance and reactivation of morphine dependence in place preference tests while lowering tolerance and dose requirements. Our future studies remain to address these potential benefits that may accompany the cholecystokinin B receptor biological therapy. Both chronic sciatic and orofacial pain can be unrelenting and excruciating, reducing quality of life as well as diminishing physical and mental function. An effective non-opiate, non-addictive therapy with potential to significantly reduce chronic neuropathic pain long term is greatly needed.
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Key Words
- ANOVA, analysis of variance
- ARM, antibody ribosome mRNA
- Anxiety
- BBB, blood–brain barrier
- CCK-8, cholecystokinin octapeptide
- CCK-BR, cholecystokinin B receptor
- CPP, conditioned place preference
- Chronic pain
- DRG, dorsal root ganglia
- Depression
- Eukaryotic ribosome display
- FRICT-ION, foramen rotundum inflammatory compression trigeminal infraorbital nerve model
- GPCR, G-protein-coupled receptor
- IACUC, Institutional Animal Care and Use Committee
- ION, infraorbital nerve
- MΩ, megaOhms
- PBS, phosphate buffered saline
- SEM, standard error of the mean
- TG, trigeminal ganglia
- ms, milliseconds
- pA, picoAmps
- scFv
- scFv, single-chain Fragment variable antibody
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Affiliation(s)
- K.N. Westlund
- Department of Anesthesiology & Critical Care Medicine, University of
New Mexico Health Sciences Center, Albuquerque, NM 87106-0001, USA
- Biomedical Laboratory Research & Development (121F), New Mexico VA
Health Care System, Albuquerque, NM, USA
| | - M.A. Montera
- Department of Anesthesiology & Critical Care Medicine, University of
New Mexico Health Sciences Center, Albuquerque, NM 87106-0001, USA
| | - A.E. Goins
- Department of Anesthesiology & Critical Care Medicine, University of
New Mexico Health Sciences Center, Albuquerque, NM 87106-0001, USA
| | - S.R.A. Alles
- Department of Anesthesiology & Critical Care Medicine, University of
New Mexico Health Sciences Center, Albuquerque, NM 87106-0001, USA
| | - M. Afaghpour-Becklund
- Department of Anesthesiology & Critical Care Medicine, University of
New Mexico Health Sciences Center, Albuquerque, NM 87106-0001, USA
| | - R. Bartel
- Department of Anesthesiology & Critical Care Medicine, University of
New Mexico Health Sciences Center, Albuquerque, NM 87106-0001, USA
| | - R. Durvasula
- Division of Infectious Diseases, Department of Internal Medicine, Mayo
Clinic, Jacksonville, FL, USA
- Department of Medicine, Loyola University Medical Center, Maywood, IL
60153-3328, USA
| | - A. Kunamneni
- Division of Infectious Diseases, Department of Internal Medicine, Mayo
Clinic, Jacksonville, FL, USA
- Department of Medicine, Loyola University Medical Center, Maywood, IL
60153-3328, USA
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18
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Wercberger R, Braz JM, Weinrich JA, Basbaum AI. Pain and itch processing by subpopulations of molecularly diverse spinal and trigeminal projection neurons. Proc Natl Acad Sci U S A 2021; 118:e2105732118. [PMID: 34234018 PMCID: PMC8285968 DOI: 10.1073/pnas.2105732118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
A remarkable molecular and functional heterogeneity of the primary sensory neurons and dorsal horn interneurons transmits pain- and or itch-relevant information, but the molecular signature of the projection neurons that convey the messages to the brain is unclear. Here, using retro-TRAP (translating ribosome affinity purification) and RNA sequencing, we reveal extensive molecular diversity of spino- and trigeminoparabrachial projection neurons. Among the many genes identified, we highlight distinct subsets of Cck+ -, Nptx2+ -, Nmb+ -, and Crh+ -expressing projection neurons. By combining in situ hybridization of retrogradely labeled neurons with Fos-based assays, we also demonstrate significant functional heterogeneity, including both convergence and segregation of pain- and itch-provoking inputs into molecularly diverse subsets of NK1R- and non-NK1R-expressing projection neurons.
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Affiliation(s)
- Racheli Wercberger
- Department of Anatomy, University of California, San Francisco, CA 94158
| | - Joao M Braz
- Department of Anatomy, University of California, San Francisco, CA 94158
| | - Jarret A Weinrich
- Department of Anatomy, University of California, San Francisco, CA 94158
| | - Allan I Basbaum
- Department of Anatomy, University of California, San Francisco, CA 94158
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19
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Sinha GP, Prasoon P, Smith BN, Taylor BK. Fast A-type currents shape a rapidly adapting form of delayed short latency firing of excitatory superficial dorsal horn neurons that express the neuropeptide Y Y1 receptor. J Physiol 2021; 599:2723-2750. [PMID: 33768539 DOI: 10.1113/jp281033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/17/2021] [Indexed: 01/29/2023] Open
Abstract
KEY POINTS Neuropeptide Y Y1 receptor-expressing neurons in the dorsal horn of the spinal cord contribute to chronic pain. For the first time, we characterized the firing patterns of Y1-expressing neurons in Y1eGFP reporter mice. Under hyperpolarized conditions, most Y1eGFP neurons exhibited fast A-type potassium currents and delayed, short-latency firing (DSLF). Y1eGFP DSLF neurons were almost always rapidly adapting and often exhibited rebound spiking, characteristics of spinal pain neurons under the control of T-type calcium channels. These results will inspire future studies to determine whether tissue or nerve injury downregulates the channels that underlie A-currents, thus unmasking membrane hyperexcitability in Y1-expressing dorsal horn neurons, leading to persistent pain. ABSTRACT Neuroanatomical and behavioural evidence indicates that neuropeptide Y Y1 receptor-expressing interneurons (Y1-INs) in the superficial dorsal horn (SDH) are predominantly excitatory and contribute to chronic pain. Using an adult ex vivo spinal cord slice preparation from Y1eGFP reporter mice, we characterized firing patterns in response to steady state depolarizing current injection of GFP-positive cells in lamina II, the great majority of which expressed Y1 mRNA (88%). Randomly sampled (RS) and Y1eGFP neurons exhibited five firing patterns: tonic, initial burst, phasic, delayed short-latency <180 ms (DSLF) and delayed long-latency >180 ms (DLLF). When studied at resting membrane potential, most RS neurons exhibited delayed firing, while most Y1eGFP neurons exhibited phasic firing. A preconditioning membrane hyperpolarization produced only subtle changes in the firing patterns of RS neurons, but dramatically shifted Y1eGFP neurons to DSLF (46%) and DLLF (24%). In contrast to RS DSLF neurons, which rarely exhibited spike frequency adaptation, Y1eGFP DSLF neurons were almost always rapidly adapting, a characteristic of nociceptive-responsive SDH neurons. Rebound spiking was more prevalent in Y1eGFP neurons (6% RS vs. 32% Y1eGFP), indicating enrichment of T-type calcium currents. Y1eGFP DSLF neurons exhibited fast A-type potassium currents that are known to delay or limit action potential firing and exhibited smaller current density as compared to RS DSLF neurons. Our results will inspire future studies to determine whether tissue or nerve injury downregulates channels that contribute to A-currents, thus potentially unmasking T-type calcium channel activity and membrane hyperexcitability in Y1-INs, leading to persistent pain.
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Affiliation(s)
- Ghanshyam P Sinha
- Department of Anesthesiology and Perioperative Medicine, Pittsburgh Center for Pain Research, and the Pittsburgh Project to end Opioid Misuse, University of Pittsburgh, Pittsburgh, PA, USA
| | - Pranav Prasoon
- Department of Anesthesiology and Perioperative Medicine, Pittsburgh Center for Pain Research, and the Pittsburgh Project to end Opioid Misuse, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bret N Smith
- Department of Neuroscience, University of Kentucky, Lexington, KY, USA
| | - Bradley K Taylor
- Department of Anesthesiology and Perioperative Medicine, Pittsburgh Center for Pain Research, and the Pittsburgh Project to end Opioid Misuse, University of Pittsburgh, Pittsburgh, PA, USA
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20
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Das Gupta RR, Scheurer L, Pelczar P, Wildner H, Zeilhofer HU. Neuron-specific spinal cord translatomes reveal a neuropeptide code for mouse dorsal horn excitatory neurons. Sci Rep 2021; 11:5232. [PMID: 33664406 PMCID: PMC7933427 DOI: 10.1038/s41598-021-84667-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/16/2021] [Indexed: 01/24/2023] Open
Abstract
The spinal dorsal horn harbors a sophisticated and heterogeneous network of excitatory and inhibitory neurons that process peripheral signals encoding different sensory modalities. Although it has long been recognized that this network is crucial both for the separation and the integration of sensory signals of different modalities, a systematic unbiased approach to the use of specific neuromodulatory systems is still missing. Here, we have used the translating ribosome affinity purification (TRAP) technique to map the translatomes of excitatory glutamatergic (vGluT2+) and inhibitory GABA and/or glycinergic (vGAT+ or Gad67+) neurons of the mouse spinal cord. Our analyses demonstrate that inhibitory and excitatory neurons are not only set apart, as expected, by the expression of genes related to the production, release or re-uptake of their principal neurotransmitters and by genes encoding for transcription factors, but also by a differential engagement of neuromodulator, especially neuropeptide, signaling pathways. Subsequent multiplex in situ hybridization revealed eleven neuropeptide genes that are strongly enriched in excitatory dorsal horn neurons and display largely non-overlapping expression patterns closely adhering to the laminar and presumably also functional organization of the spinal cord grey matter.
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Affiliation(s)
- Rebecca Rani Das Gupta
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.,Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Vladimir-Prelog-Weg 1-5/10, 8090, Zurich, Switzerland
| | - Louis Scheurer
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Pawel Pelczar
- Center for Transgenic Models, University of Basel, 4001, Basel, Switzerland
| | - Hendrik Wildner
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
| | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. .,Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Vladimir-Prelog-Weg 1-5/10, 8090, Zurich, Switzerland.
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21
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Spinal Excitatory Dynorphinergic Interneurons Contribute to Burn Injury-Induced Nociception Mediated by Phosphorylated Histone 3 at Serine 10 in Rodents. Int J Mol Sci 2021; 22:ijms22052297. [PMID: 33669046 PMCID: PMC7956488 DOI: 10.3390/ijms22052297] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/20/2021] [Accepted: 02/21/2021] [Indexed: 12/18/2022] Open
Abstract
The phosphorylation of serine 10 in histone 3 (p-S10H3) has recently been demonstrated to participate in spinal nociceptive processing. However, superficial dorsal horn (SDH) neurons involved in p-S10H3-mediated nociception have not been fully characterized. In the present work, we combined immunohistochemistry, in situ hybridization with the retrograde labeling of projection neurons to reveal the subset of dorsal horn neurons presenting an elevated level of p-S10H3 in response to noxious heat (60 °C), causing burn injury. Projection neurons only represented a small percentage (5%) of p-S10H3-positive cells, while the greater part of them belonged to excitatory SDH interneurons. The combined immunolabeling of p-S10H3 with markers of already established interneuronal classes of the SDH revealed that the largest subset of neurons with burn injury-induced p-S10H3 expression was dynorphin immunopositive in mice. Furthermore, the majority of p-S10H3-expressing dynorphinergic neurons proved to be excitatory, as they lacked Pax-2 and showed Lmx1b-immunopositivity. Thus, we showed that neurochemically heterogeneous SDH neurons exhibit the upregulation of p-S10H3 shortly after noxious heat-induced burn injury and consequential tissue damage, and that a dedicated subset of excitatory dynorphinergic neurons is likely a key player in the development of central sensitization via the p-S10H3 mediated pathway.
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22
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Gatto G, Bourane S, Ren X, Di Costanzo S, Fenton PK, Halder P, Seal RP, Goulding MD. A Functional Topographic Map for Spinal Sensorimotor Reflexes. Neuron 2021; 109:91-104.e5. [PMID: 33181065 PMCID: PMC7790959 DOI: 10.1016/j.neuron.2020.10.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/17/2020] [Accepted: 09/30/2020] [Indexed: 01/02/2023]
Abstract
Cutaneous somatosensory modalities play pivotal roles in generating a wide range of sensorimotor behaviors, including protective and corrective reflexes that dynamically adapt ongoing movement and posture. How interneurons (INs) in the dorsal horn encode these modalities and transform them into stimulus-appropriate motor behaviors is not known. Here, we use an intersectional genetic approach to functionally assess the contribution that eight classes of dorsal excitatory INs make to sensorimotor reflex responses. We demonstrate that the dorsal horn is organized into spatially restricted excitatory modules composed of molecularly heterogeneous cell types. Laminae I/II INs drive chemical itch-induced scratching, laminae II/III INs generate paw withdrawal movements, and laminae III/IV INs modulate dynamic corrective reflexes. These data reveal a key principle in spinal somatosensory processing, namely, sensorimotor reflexes are driven by the differential spatial recruitment of excitatory neurons.
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Affiliation(s)
- Graziana Gatto
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Steeve Bourane
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Université de la Réunion, DéTROI, UMR 1188 INSERM, Sainte Clotilde, La Réunion 97490, France
| | - Xiangyu Ren
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Biology Graduate Program, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stefania Di Costanzo
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Biology Graduate Program, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Peter K Fenton
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Priyabrata Halder
- Departments of Neurobiology and Otolaryngology, Center for Neural Basis of Cognition, and Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Rebecca P Seal
- Departments of Neurobiology and Otolaryngology, Center for Neural Basis of Cognition, and Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Martyn D Goulding
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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23
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Peirs C, Williams SPG, Zhao X, Arokiaraj CM, Ferreira DW, Noh MC, Smith KM, Halder P, Corrigan KA, Gedeon JY, Lee SJ, Gatto G, Chi D, Ross SE, Goulding M, Seal RP. Mechanical Allodynia Circuitry in the Dorsal Horn Is Defined by the Nature of the Injury. Neuron 2020; 109:73-90.e7. [PMID: 33181066 DOI: 10.1016/j.neuron.2020.10.027] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 09/16/2020] [Accepted: 10/20/2020] [Indexed: 12/13/2022]
Abstract
The spinal dorsal horn is a major site for the induction and maintenance of mechanical allodynia, but the circuitry that underlies this clinically important form of pain remains unclear. The studies presented here provide strong evidence that the neural circuits conveying mechanical allodynia in the dorsal horn differ by the nature of the injury. Calretinin (CR) neurons in lamina II inner convey mechanical allodynia induced by inflammatory injuries, while protein kinase C gamma (PKCγ) neurons at the lamina II/III border convey mechanical allodynia induced by neuropathic injuries. Cholecystokinin (CCK) neurons located deeper within the dorsal horn (laminae III-IV) are important for both types of injuries. Interestingly, the Maf+ subset of CCK neurons is composed of transient vesicular glutamate transporter 3 (tVGLUT3) neurons, which convey primarily dynamic allodynia. Identification of an etiology-based circuitry for mechanical allodynia in the dorsal horn has important implications for the mechanistic and clinical understanding of this condition.
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Affiliation(s)
- Cedric Peirs
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Sean-Paul G Williams
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Xinyi Zhao
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Cynthia M Arokiaraj
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - David W Ferreira
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Myung-Chul Noh
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Kelly M Smith
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Priyabrata Halder
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Kelly A Corrigan
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Jeremy Y Gedeon
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Suh Jin Lee
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Graziana Gatto
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA
| | - David Chi
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Sarah E Ross
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Martyn Goulding
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Rebecca P Seal
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA.
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24
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Effects of soy protein isolate hydrolysates on cholecystokinin released by rat intestinal mucosal cells and food intake in rats. Journal of Food Science and Technology 2020; 57:4459-4468. [PMID: 33087959 DOI: 10.1007/s13197-020-04483-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 02/20/2020] [Accepted: 04/24/2020] [Indexed: 12/19/2022]
Abstract
Soy protein isolate hydrolysates (SPIH) were prepared from soy protein isolate (SPI). Effects of SPIH on a satiety signal cholecystokinin (CCK) and feeding behavior in rats were investigated. SPIH induced more CCK release (164.66 ± 2.40 pg/mL) by rat intestinal mucosal cells than SPI (143.33 ± 3.71 pg/mL). Meal size (MS), intermeal interval (IMI), and satiety ratio (SR = MS/IMI) of rats received different daily doses of SPIH or dietary fiber were detected for 40 days. A 100 mg/kg dose of SPIH resulted in a greater SR than an identical dose of dietary fiber, while a 300 mg/kg dose resulted in a less MS and IMI. A 500 mg/kg dose of SPIH had similar effects to the same dose of dietary fiber on reducing MS, extending IMI, and increasing SR, but resulted in a significantly less body weight at the end of the experiment (318.15 ± 17.83 g) than the dietary fiber group (340.28 ± 6.15 g).
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25
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Nakagawa T, Yasaka T, Nakashima N, Takeya M, Oshita K, Tsuda M, Yamaura K, Takano M. Expression of the pacemaker channel HCN4 in excitatory interneurons in the dorsal horn of the murine spinal cord. Mol Brain 2020; 13:127. [PMID: 32948209 PMCID: PMC7501643 DOI: 10.1186/s13041-020-00666-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 09/07/2020] [Indexed: 11/17/2022] Open
Abstract
In the central nervous system, hyperpolarization-activated, cyclic nucleotide-gated (HCN1–4) channels have been implicated in neuronal excitability and synaptic transmission. It has been reported that HCN channels are expressed in the spinal cord, but knowledge about their physiological roles, as well as their distribution profiles, appear to be limited. We generated a transgenic mouse in which the expression of HCN4 can be reversibly knocked down using a genetic tetracycline-dependent switch and conducted genetically validated immunohistochemistry for HCN4. We found that the somata of HCN4-immunoreactive (IR) cells were largely restricted to the ventral part of the inner lamina II and lamina III. Many of these cells were either parvalbumin- or protein kinase Cγ (PKCγ)-IR. By using two different mouse strains in which reporters are expressed only in inhibitory neurons, we determined that the vast majority of HCN4-IR cells were excitatory neurons. Mechanical and thermal noxious stimulation did not induce c-Fos expression in HCN4-IR cells. PKCγ-neurons in this area are known to play a pivotal role in the polysynaptic pathway between tactile afferents and nociceptive projection cells that contributes to tactile allodynia. Therefore, pharmacological and/or genetic manipulations of HCN4-expressing neurons may provide a novel therapeutic strategy for the pain relief of tactile allodynia.
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Affiliation(s)
- Taku Nakagawa
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan.,Department of Anesthesiology, Graduate School of Medicine, Kyushu University, Fukuoka, 812-8582, Japan
| | - Toshiharu Yasaka
- Department of Health and Nutrition, Niigata University of Hearth and Welfare, Niigata, 950-3198, Japan
| | - Noriyuki Nakashima
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Mitsue Takeya
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Kensuke Oshita
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan.,Department of Anesthesiology, Kurume University School of Medicine, Kurume, 830-0011, Japan
| | - Makoto Tsuda
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Ken Yamaura
- Department of Anesthesiology, Graduate School of Medicine, Kyushu University, Fukuoka, 812-8582, Japan
| | - Makoto Takano
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan.
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26
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Bell AM, Gutierrez-Mecinas M, Stevenson A, Casas-Benito A, Wildner H, West SJ, Watanabe M, Todd AJ. Expression of green fluorescent protein defines a specific population of lamina II excitatory interneurons in the GRP::eGFP mouse. Sci Rep 2020; 10:13176. [PMID: 32764601 PMCID: PMC7411045 DOI: 10.1038/s41598-020-69711-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 07/15/2020] [Indexed: 01/27/2023] Open
Abstract
Dorsal horn excitatory interneurons that express gastrin-releasing peptide (GRP) are part of the circuit for pruritogen-evoked itch. They have been extensively studied in a transgenic line in which enhanced green fluorescent protein (eGFP) is expressed under control of the Grp gene. The GRP-eGFP cells are separate from several other neurochemically-defined excitatory interneuron populations, and correspond to a class previously defined as transient central cells. However, mRNA for GRP is widely distributed among excitatory interneurons in superficial dorsal horn. Here we show that although Grp mRNA is present in several transcriptomically-defined populations, eGFP is restricted to a discrete subset of cells in the GRP::eGFP mouse, some of which express the neuromedin receptor 2 and likely belong to a cluster defined as Glut8. We show that these cells receive much of their excitatory synaptic input from MrgA3/MrgD-expressing nociceptive/pruritoceptive afferents and C-low threshold mechanoreceptors. Although the cells were not innervated by pruritoceptors expressing brain natriuretic peptide (BNP) most of them contained mRNA for NPR1, the receptor for BNP. In contrast, these cells received only ~ 10% of their excitatory input from other interneurons. These findings demonstrate that the GRP-eGFP cells constitute a discrete population of excitatory interneurons with a characteristic pattern of synaptic input.
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Affiliation(s)
- Andrew M Bell
- Spinal Cord Group, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, Glasgow, G12 8QQ, UK.
| | - Maria Gutierrez-Mecinas
- Spinal Cord Group, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, Glasgow, G12 8QQ, UK
| | - Anna Stevenson
- Spinal Cord Group, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, Glasgow, G12 8QQ, UK
| | - Adrian Casas-Benito
- Spinal Cord Group, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, Glasgow, G12 8QQ, UK
| | - Hendrik Wildner
- Institute of Pharmacology and Toxicology, University of Zurich, Zürich, Switzerland.,Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
| | - Steven J West
- The Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo, 060-8638, Japan
| | - Andrew J Todd
- Spinal Cord Group, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir James Black Building, Glasgow, G12 8QQ, UK.
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27
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Polgár E, Bell AM, Gutierrez-Mecinas M, Dickie AC, Akar O, Costreie M, Watanabe M, Todd AJ. Substance P-expressing Neurons in the Superficial Dorsal Horn of the Mouse Spinal Cord: Insights into Their Functions and their Roles in Synaptic Circuits. Neuroscience 2020; 450:113-125. [PMID: 32634530 PMCID: PMC7717171 DOI: 10.1016/j.neuroscience.2020.06.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 11/26/2022]
Abstract
Substance P-expressing radial cells in lamina II receive half of their excitatory synaptic input from other interneurons. They are preferentially innervated by transient central cells that express eGFP in a GRP-eGFP mouse line. Around 40% of projection neurons in lamina I express Tac1, the gene for substance P. Silencing Tac1 cells in the dorsal horn reduces reflex responses to cold and radiant heat.
The tachykinin peptide substance P (SP) is expressed by many interneurons and some projection neurons in the superficial dorsal horn of the spinal cord. We have recently shown that SP-expressing excitatory interneurons in lamina II correspond largely to a morphological class known as radial cells. However, little is known about their function, or their synaptic connectivity. Here we use a modification of the Brainbow technique to define the excitatory synaptic input to SP radial cells. We show that around half of their excitatory synapses (identified by expression of Homer) are from boutons with VGLUT2, which are likely to originate mainly from local interneurons. The remaining synapses presumably include primary afferents, which generally have very low levels of VGLUT2. Our results also suggest that the SP cells are preferentially innervated by a population of excitatory interneurons defined by expression of green fluorescent protein under control of the gene for gastrin-releasing peptide, and that they receive sparser input from other types of excitatory interneuron. We show that around 40% of lamina I projection neurons express Tac1, the gene encoding substance P. Finally, we show that silencing Tac1-expressing cells in the dorsal horn results in a significant reduction in reflex responses to cold and radiant heat, but does not affect withdrawal to von Frey hairs, or chloroquine-evoked itch.
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Affiliation(s)
- Erika Polgár
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Andrew M Bell
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Maria Gutierrez-Mecinas
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Allen C Dickie
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Oğuz Akar
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Miruna Costreie
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo 060-8638, Japan
| | - Andrew J Todd
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
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28
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Peirs C, Dallel R, Todd AJ. Recent advances in our understanding of the organization of dorsal horn neuron populations and their contribution to cutaneous mechanical allodynia. J Neural Transm (Vienna) 2020; 127:505-525. [PMID: 32239353 PMCID: PMC7148279 DOI: 10.1007/s00702-020-02159-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/10/2020] [Indexed: 02/07/2023]
Abstract
The dorsal horns of the spinal cord and the trigeminal nuclei in the brainstem contain neuron populations that are critical to process sensory information. Neurons in these areas are highly heterogeneous in their morphology, molecular phenotype and intrinsic properties, making it difficult to identify functionally distinct cell populations, and to determine how these are engaged in pathophysiological conditions. There is a growing consensus concerning the classification of neuron populations, based on transcriptomic and transductomic analyses of the dorsal horn. These approaches have led to the discovery of several molecularly defined cell types that have been implicated in cutaneous mechanical allodynia, a highly prevalent and difficult-to-treat symptom of chronic pain, in which touch becomes painful. The main objective of this review is to provide a contemporary view of dorsal horn neuronal populations, and describe recent advances in our understanding of on how they participate in cutaneous mechanical allodynia.
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Affiliation(s)
- Cedric Peirs
- Université Clermont Auvergne, CHU Clermont-Ferrand, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Radhouane Dallel
- Université Clermont Auvergne, CHU Clermont-Ferrand, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andrew J Todd
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
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Wercberger R, Basbaum AI. Spinal cord projection neurons: a superficial, and also deep, analysis. CURRENT OPINION IN PHYSIOLOGY 2019; 11:109-115. [PMID: 32864531 DOI: 10.1016/j.cophys.2019.10.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Today there are extensive maps of the molecular heterogeneity of primary afferents and dorsal horn interneurons, yet there is a dearth of molecular and functional information regarding the projection neurons that transmit pain and itch information to the brain. Additionally, most contemporary research into the spinal cord and medullary projection neurons focuses on neurons in the superficial dorsal horn; the contribution of deep dorsal horn and even ventral horn projection neurons to pain and itch processing is often overlooked. In the present review we integrate conclusions from classical as well as contemporary studies and provide a more balanced view of the diversity of projection neurons. A major question addressed is the extent to which labeled-lines are maintained in these different populations or whether the brain generates distinct pain and itch percepts by decoding complex convergent inputs that engage projection neurons.
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Affiliation(s)
- Racheli Wercberger
- Department of Anatomy and Neuroscience Graduate Program, University California San Francisco, San Francisco, CA 94158
| | - Allan I Basbaum
- Department of Anatomy and Neuroscience Graduate Program, University California San Francisco, San Francisco, CA 94158
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30
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Gutierrez-Mecinas M, Bell A, Polgár E, Watanabe M, Todd AJ. Expression of Neuropeptide FF Defines a Population of Excitatory Interneurons in the Superficial Dorsal Horn of the Mouse Spinal Cord that Respond to Noxious and Pruritic Stimuli. Neuroscience 2019; 416:281-293. [PMID: 31421202 PMCID: PMC6839401 DOI: 10.1016/j.neuroscience.2019.08.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 07/15/2019] [Accepted: 08/06/2019] [Indexed: 12/16/2022]
Abstract
The great majority of neurons in the superficial dorsal horn of the spinal cord are excitatory interneurons, and these are required for the normal perception of pain and itch. We have previously identified 5 largely non-overlapping populations among these cells, based on the expression of four different neuropeptides (cholecystokinin, neurotensin, neurokinin B and substance P) and of green fluorescent protein driven by the promoter for gastrin-releasing peptide (GRP) in a transgenic mouse line. Another peptide (neuropeptide FF, NPFF) has been identified among the excitatory neurons, and here we have used an antibody against the NPFF precursor (pro-NPFF) and a probe that recognises Npff mRNA to identify and characterise these cells. We show that they are all excitatory interneurons, and are separate from the five populations listed above, accounting for ~ 6% of the excitatory neurons in laminae I-II. By examining phosphorylation of extracellular signal-regulated kinases, we show that the NPFF cells can respond to different types of noxious and pruritic stimulus. Ablation of somatostatin-expressing dorsal horn neurons has been shown to result in a dramatic reduction in mechanical pain sensitivity, while somatostatin released from these neurons is thought to contribute to itch. Since the great majority of the NPFF cells co-expressed somatostatin, these cells may play a role in the perception of pain and itch. NPFF is expressed by around 6% of the excitatory interneurons in the superficial dorsal horn of the mouse spinal cord. NPFF cells differ from those that express substance P, cholecystokinin, neurotensin or neurokinin B. Although some NPFF cells express gastrin-releasing peptide (GRP), they do not express GFP in a GRP-GFP mouse line. Some NPFF cells are activated by noxious or pruritic stimuli.
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Affiliation(s)
- Maria Gutierrez-Mecinas
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andrew Bell
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Erika Polgár
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo 060-8638, Japan
| | - Andrew J Todd
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
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Gutierrez‐Mecinas M, Bell AM, Shepherd F, Polgár E, Watanabe M, Furuta T, Todd AJ. Expression of cholecystokinin by neurons in mouse spinal dorsal horn. J Comp Neurol 2019; 527:1857-1871. [PMID: 30734936 PMCID: PMC6563475 DOI: 10.1002/cne.24657] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 01/25/2019] [Accepted: 02/02/2019] [Indexed: 12/22/2022]
Abstract
Excitatory interneurons account for the majority of dorsal horn neurons, and are required for perception of normal and pathological pain. We have identified largely non-overlapping populations in laminae I-III, based on expression of substance P, gastrin-releasing peptide, neurokinin B, and neurotensin. Cholecystokinin (CCK) is expressed by many dorsal horn neurons, particularly in the deeper laminae. Here, we have used immunocytochemistry and in situ hybridization to characterize the CCK cells. We show that they account for ~7% of excitatory neurons in laminae I-II, but between a third and a quarter of those in lamina III. They are largely separate from the neurokinin B, neurotensin, and gastrin-releasing peptide populations, but show limited overlap with the substance P cells. Laminae II-III neurons with protein kinase Cγ (PKCγ) have been implicated in mechanical allodynia following nerve injury, and we found that around 50% of CCK cells were PKCγ-immunoreactive. Neurotensin is also expressed by PKCγ cells, and among neurons with moderate to high levels of PKCγ, ~85% expressed CCK or neurotensin. A recent transcriptomic study identified mRNA for thyrotropin-releasing hormone in a specific subpopulation of CCK neurons, and we show that these account for half of the CCK/PKCγ cells. These findings indicate that the CCK cells are distinct from other excitatory interneuron populations that we have defined. They also show that PKCγ cells can be assigned to different classes based on neuropeptide expression, and it will be important to determine the differential contribution of these classes to neuropathic allodynia.
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Affiliation(s)
- Maria Gutierrez‐Mecinas
- Institute of Neuroscience and Psychology, College of Medical, Veterinary & Life Sciences, University of GlasgowGlasgowUnited Kingdom
| | - Andrew M. Bell
- Institute of Neuroscience and Psychology, College of Medical, Veterinary & Life Sciences, University of GlasgowGlasgowUnited Kingdom
| | - Fraser Shepherd
- Institute of Neuroscience and Psychology, College of Medical, Veterinary & Life Sciences, University of GlasgowGlasgowUnited Kingdom
| | - Erika Polgár
- Institute of Neuroscience and Psychology, College of Medical, Veterinary & Life Sciences, University of GlasgowGlasgowUnited Kingdom
| | - Masahiko Watanabe
- Department of AnatomyHokkaido University School of MedicineSapporoJapan
| | - Takahiro Furuta
- Department of Oral Anatomy and Neurobiology, Graduate School of DentistryOsaka UniversityOsakaJapan
| | - Andrew J. Todd
- Institute of Neuroscience and Psychology, College of Medical, Veterinary & Life Sciences, University of GlasgowGlasgowUnited Kingdom
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