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Hayashi K, Lesnak JB, Plumb AN, Janowski AJ, Smith AF, Hill JK, Sluka KA. Brain-derived neurotrophic factor contributes to activity-induced muscle pain in male but not female mice. Brain Behav Immun 2024; 120:471-487. [PMID: 38925417 DOI: 10.1016/j.bbi.2024.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 06/21/2024] [Accepted: 06/23/2024] [Indexed: 06/28/2024] Open
Abstract
Activity-induced muscle pain increases interleukin-1β (IL-1β) release from muscle macrophages and the development of hyperalgesia is prevented by blockade of IL-1β in muscle. Brain derived neurotrophic factor (BDNF) is released from sensory neurons in response to IL-1β and mediates both inflammatory and neuropathic pain. Thus, we hypothesize that in activity-induced pain, fatigue metabolites combined with IL-1β activate sensory neurons to increase BDNF release, peripherally in muscle and centrally in the spinal dorsal horn, to produce hyperalgesia. We tested the effect of intrathecal or intramuscular injection of BDNF-Tropomyosin receptor kinase B (TrkB) inhibitors, ANA-12 or TrkB-Fc, on development of activity-induced pain. Both inhibitors prevented the hyperalgesia when given before or 24hr after induction of the model in male but not female mice. BDNF messenger ribonucleic acid (mRNA) and protein were significantly increased in dorsal root ganglion (DRG) 24hr after induction of the model in both male and female mice. Blockade of IL-1β in muscle had no effect on the increased BNDF mRNA observed in the activity-induced pain model, while IL-1β applied to cultured DRG significantly induced BDNF expression, suggesting IL-1β is sufficient but not necessary to induce BNDF. Thus, fatigue metabolites, combined with IL-1β, upregulate BDNF in primary DRG neurons in both male and female mice, but contribute to activity-induced pain only in males.
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Affiliation(s)
- Kazuhiro Hayashi
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA; Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Joseph B Lesnak
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Ashley N Plumb
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Adam J Janowski
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Angela F Smith
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Joslyn K Hill
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Kathleen A Sluka
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA.
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2
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Calvillo-Montoya DL, Martínez-Magaña CJ, Oviedo N, Murbartián J. The Estrogen Receptor Alpha Regulates the Sex-dependent Expression and Pronociceptive Role of Bestrophin-1 in Neuropathic Rats. THE JOURNAL OF PAIN 2024; 25:104513. [PMID: 38521145 DOI: 10.1016/j.jpain.2024.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 02/21/2024] [Accepted: 03/14/2024] [Indexed: 03/25/2024]
Abstract
Bestrophin-1, a calcium-activated chloride channel (CaCC), is involved in neuropathic pain; however, it is unclear whether it has a dimorphic role in female and male neuropathic rats. This study investigated if 17β-estradiol and estrogen receptor alpha (ERα) activation regulate bestrophin-1 activity and expression in neuropathic rats. Neuropathic pain was induced by L5-spinal nerve transection (SNT). Intrathecal administration of CaCCinh-A01 (.1-1 µg), a CaCC blocker, reversed tactile allodynia induced by SNT in female but not male rats. In contrast, T16Ainh-A01, a selective anoctamin-1 blocker, had an equal antiallodynic effect in both sexes. SNT increased bestrophin-1 protein expression in injured L5 dorsal root ganglia (DRG) in female rats but decreased bestrophin-1 protein in L5 DRG in male rats. Ovariectomy prevented the antiallodynic effect of CaCCinh-A01, but 17β-estradiol replacement restored it. The effect of CaCCinh-A01 was prevented by intrathecal administration of MPP, a selective ERα antagonist, in rats with and without prior hormonal manipulation. In female rats with neuropathy, ovariectomy prevented the increase in bestrophin-1 and ERα protein expression, while 17β-estradiol replacement allowed for an increase in both proteins in L5 DRG. Furthermore, ERα antagonism (with MPP) prevented the increase in bestrophin-1 and ERα protein expression. Finally, ERα activation with PPT, an ERα selective activator, induced the antiallodynic effect of CaCCinh-A01 in neuropathic male rats and prevented the reduction in bestrophin-1 protein expression in L5 DRG. In summary, data suggest ERα activation is necessary for bestrophin-1's pronociceptive action to maintain neuropathic pain in female rats. PERSPECTIVE: The mechanisms involved in neuropathic pain differ between male and female animals. Our data suggest that ERα is necessary for expression and function of bestrophin-1 in neuropathic female but not male rats. Data support the idea that a therapeutic approach to relieving neuropathic pain must be based on patient's gender.
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Affiliation(s)
| | | | - Norma Oviedo
- Unidad de Investigación Médica en Inmunología e Infectología, Centro Médico Nacional, La Raza, IMSS, Mexico City, Mexico
| | - Janet Murbartián
- Department of Pharmacobiologý, Cinvestav, South Campus, Mexico City, Mexico.
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3
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Franco-Enzástiga Ú, Inturi NN, Natarajan K, Mwirigi JM, Mazhar K, Schlachetzki JC, Schumacher M, Price TJ. Epigenomic landscape of the human dorsal root ganglion: sex differences and transcriptional regulation of nociceptive genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.27.587047. [PMID: 38586055 PMCID: PMC10996669 DOI: 10.1101/2024.03.27.587047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Gene expression is influenced by chromatin architecture via controlled access of regulatory factors to DNA. To better understand gene regulation in the human dorsal root ganglion (hDRG) we used bulk and spatial transposase-accessible chromatin technology followed by sequencing (ATAC-seq). Using bulk ATAC-seq, we detected that in females diverse differentially accessible chromatin regions (DARs) mapped to the X chromosome and in males to autosomal genes. EGR1/3 and SP1/4 transcription factor binding motifs were abundant within DARs in females, and JUN, FOS and other AP-1 factors in males. To dissect the open chromatin profile in hDRG neurons, we used spatial ATAC-seq. The neuron cluster showed higher chromatin accessibility in GABAergic, glutamatergic, and interferon-related genes in females, and in Ca2+- signaling-related genes in males. Sex differences in transcription factor binding sites in neuron-proximal barcodes were consistent with the trends observed in bulk ATAC-seq data. We validated that EGR1 expression is biased to female hDRG compared to male. Strikingly, XIST, the long-noncoding RNA responsible for X inactivation, hybridization signal was found to be highly dispersed in the female neuronal but not non-neuronal nuclei suggesting weak X inactivation in female hDRG neurons. Our findings point to baseline epigenomic sex differences in the hDRG that likely underlie divergent transcriptional responses that determine mechanistic sex differences in pain.
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Affiliation(s)
- Úrzula Franco-Enzástiga
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Nikhil N. Inturi
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Keerthana Natarajan
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Juliet M. Mwirigi
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Khadija Mazhar
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Johannes C.M. Schlachetzki
- Department of Cellular and Molecular Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0651, USA
| | - Mark Schumacher
- Department of Anesthesia and Perioperative Care and the UCSF Pain and Addiction Research Center, University of California, San Francisco, California, 94143 USA
| | - Theodore J. Price
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas 75080
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4
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Kok M, Brodsky JL. The biogenesis of potassium transporters: implications of disease-associated mutations. Crit Rev Biochem Mol Biol 2024:1-45. [PMID: 38946646 DOI: 10.1080/10409238.2024.2369986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/16/2024] [Indexed: 07/02/2024]
Abstract
The concentration of intracellular and extracellular potassium is tightly regulated due to the action of various ion transporters, channels, and pumps, which reside primarily in the kidney. Yet, potassium transporters and cotransporters play vital roles in all organs and cell types. Perhaps not surprisingly, defects in the biogenesis, function, and/or regulation of these proteins are linked to range of catastrophic human diseases, but to date, few drugs have been approved to treat these maladies. In this review, we discuss the structure, function, and activity of a group of potassium-chloride cotransporters, the KCCs, as well as the related sodium-potassium-chloride cotransporters, the NKCCs. Diseases associated with each of the four KCCs and two NKCCs are also discussed. Particular emphasis is placed on how these complex membrane proteins fold and mature in the endoplasmic reticulum, how non-native forms of the cotransporters are destroyed in the cell, and which cellular factors oversee their maturation and transport to the cell surface. When known, we also outline how the levels and activities of each cotransporter are regulated. Open questions in the field and avenues for future investigations are further outlined.
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Affiliation(s)
- Morgan Kok
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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Hamze M, Brier C, Buhler E, Zhang J, Medina I, Porcher C. Regulation of Neuronal Chloride Homeostasis by Pro- and Mature Brain-Derived Neurotrophic Factor (BDNF) via KCC2 Cation-Chloride Cotransporters in Rat Cortical Neurons. Int J Mol Sci 2024; 25:6253. [PMID: 38892438 PMCID: PMC11172813 DOI: 10.3390/ijms25116253] [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: 05/17/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024] Open
Abstract
The strength of inhibitory neurotransmission depends on intracellular neuronal chloride concentration, primarily regulated by the activity of cation-chloride cotransporters NKCC1 (Sodium-Potassium-Chloride Cotransporter 1) and KCC2 (Potassium-Chloride Cotransporter 2). Brain-derived neurotrophic factor (BDNF) influences the functioning of these co-transporters. BDNF is synthesized from precursor proteins (proBDNF), which undergo proteolytic cleavage to yield mature BDNF (mBDNF). While previous studies have indicated the involvement of BDNF signaling in the activity of KCC2, its specific mechanisms are unclear. We investigated the interplay between both forms of BDNF and chloride homeostasis in rat hippocampal neurons and in utero electroporated cortices of rat pups, spanning the behavioral, cellular, and molecular levels. We found that both pro- and mBDNF play a comparable role in immature neurons by inhibiting the capacity of neurons to extrude chloride. Additionally, proBDNF increases the endocytosis of KCC2 while maintaining a depolarizing shift of EGABA in maturing neurons. Behaviorally, proBDNF-electroporated rat pups in the somatosensory cortex exhibit sensory deficits, delayed huddling, and cliff avoidance. These findings emphasize the role of BDNF signaling in regulating chloride transport through the modulation of KCC2. In summary, this study provides valuable insights into the intricate interplay between BDNF, chloride homeostasis, and inhibitory synaptic transmission, shedding light on the underlying cellular mechanisms involved.
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Affiliation(s)
- Mira Hamze
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Cathy Brier
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Emmanuelle Buhler
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Jinwei Zhang
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling Ling Road, Shanghai 200032, China;
| | - Igor Medina
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
| | - Christophe Porcher
- INMED, INSERM, Aix-Marseille University, 13273 Marseille, France; (M.H.); (C.B.); (E.B.); (I.M.)
- INSERM (Institut National de la Santé et de la Recherche Médicale), Unité 1249, Parc Scientifique de Luminy, 13273 Marseille, France
- INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, 13273 Marseille, France
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6
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Ferland S, Wang F, De Koninck Y, Ferrini F. An improved conflict avoidance assay reveals modality-specific differences in pain hypersensitivity across sexes. Pain 2024; 165:1304-1316. [PMID: 38277178 PMCID: PMC11090034 DOI: 10.1097/j.pain.0000000000003132] [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: 06/04/2023] [Revised: 10/17/2023] [Accepted: 11/06/2023] [Indexed: 01/27/2024]
Abstract
ABSTRACT Abnormal encoding of somatosensory modalities (ie, mechanical, cold, and heat) are a critical part of pathological pain states. Detailed phenotyping of patients' responses to these modalities have raised hopes that analgesic treatments could one day be tailored to a patient's phenotype. Such precise treatment would require a profound understanding of the underlying mechanisms of specific pain phenotypes at molecular, cellular, and circuitry levels. Although preclinical pain models have helped in that regard, the lack of a unified assay quantifying detailed mechanical, cold, and heat pain responses on the same scale precludes comparing how analgesic compounds act on different sensory phenotypes. The conflict avoidance assay is promising in that regard, but testing conditions require validation for its use with multiple modalities. In this study, we improve upon the conflict avoidance assay to provide a validated and detailed assessment of all 3 modalities within the same animal, in mice. We first optimized testing conditions to minimize the necessary amount of training and to reduce sex differences in performances. We then tested what range of stimuli produce dynamic stimulus-response relationships for different outcome measures in naive mice. We finally used this assay to show that nerve injury produces modality-specific sex differences in pain behavior. Our improved assay opens new avenues to study the basis of modality-specific abnormalities in pain behavior.
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Affiliation(s)
| | - Feng Wang
- CERVO Brain Research Centre, Québec, QC, Canada
- Faculty of Dentistry, Université Laval, Québec, QC, Canada
| | - Yves De Koninck
- CERVO Brain Research Centre, Québec, QC, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec, QC, Canada
| | - Francesco Ferrini
- CERVO Brain Research Centre, Québec, QC, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec, QC, Canada
- Department of Veterinary Sciences, University of Turin, Turin, Italy
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7
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Parameshwarappa V, Siponen MI, Watabe I, Karkaba A, Galazyuk A, Noreña AJ. Noise-induced hearing loss alters potassium-chloride cotransporter KCC2 and GABA inhibition in the auditory centers. Sci Rep 2024; 14:10689. [PMID: 38724641 PMCID: PMC11082187 DOI: 10.1038/s41598-024-60858-1] [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: 09/26/2023] [Accepted: 04/29/2024] [Indexed: 05/12/2024] Open
Abstract
Homeostatic plasticity, the ability of neurons to maintain their averaged activity constant around a set point value, is thought to account for the central hyperactivity after hearing loss. Here, we investigated the putative role of GABAergic neurotransmission in this mechanism after a noise-induced hearing loss larger than 50 dB in high frequencies in guinea pigs. The effect of GABAergic inhibition is linked to the normal functioning of K + -Cl- co-transporter isoform 2 (KCC2) which maintains a low intracellular concentration of chloride. The expression of membrane KCC2 were investigated before and after noise trauma in the ventral and dorsal cochlear nucleus (VCN and DCN, respectively) and in the inferior colliculus (IC). Moreover, the effect of gabazine (GBZ), a GABA antagonist, was also studied on the neural activity in IC. We show that KCC2 is downregulated in VCN, DCN and IC 3 days after noise trauma, and in DCN and IC 30 days after the trauma. As expected, GBZ application in the IC of control animals resulted in an increase of spontaneous and stimulus-evoked activity. In the noise exposed animals, on the other hand, GBZ application decreased the stimulus-evoked activity in IC neurons. The functional implications of these central changes are discussed.
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Affiliation(s)
- V Parameshwarappa
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France
| | - M I Siponen
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France
| | - I Watabe
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France
| | - A Karkaba
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France
| | - A Galazyuk
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, USA
| | - A J Noreña
- Laboratory of Cognitive Neurosciences, Centre National de la Recherche Scientifique, Aix-Marseille University, 3 Place Victor Hugo, 13003, Marseille, France.
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8
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Ju YH, Cho J, Park JY, Kim H, Hong EB, Lee CJ, Chung E, Kim HI, Nam MH. Tonic excitation by astrocytic GABA causes neuropathic pain by augmenting neuronal activity and glucose metabolism. Exp Mol Med 2024; 56:1193-1205. [PMID: 38760512 PMCID: PMC11148027 DOI: 10.1038/s12276-024-01232-z] [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: 11/18/2023] [Revised: 02/21/2024] [Accepted: 02/29/2024] [Indexed: 05/19/2024] Open
Abstract
Neuropathic pain is a debilitating condition caused by the hyperexcitability of spinal dorsal horn neurons and is often characterized by allodynia. Although neuron-independent mechanisms of hyperexcitability have been investigated, the contribution of astrocyte-neuron interactions remains unclear. Here, we show evidence of reactive astrocytes and their excessive GABA release in the spinal dorsal horn, which paradoxically leads to the tonic excitation of neighboring neurons in a neuropathic pain model. Using multiple electrophysiological methods, we demonstrated that neuronal hyperexcitability is attributed to both increased astrocytic GABA synthesis via monoamine oxidase B (MAOB) and the depolarized reversal potential of GABA-mediated currents (EGABA) via the downregulation of the neuronal K+/Cl- cotransporter KCC2. Furthermore, longitudinal 2-deoxy-2-[18F]-fluoro-D-glucose microPET imaging demonstrated increased regional glucose metabolism in the ipsilateral dorsal horn, reflecting neuronal hyperexcitability. Importantly, inhibiting MAOB restored the entire astrocytic GABA-mediated cascade and abrogated the increased glucose metabolism and mechanical allodynia. Overall, astrocytic GABA-mediated tonic excitation is critical for neuronal hyperexcitability, leading to mechanical allodynia and neuropathic pain.
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Affiliation(s)
- Yeon Ha Ju
- Center for Brain Function, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Jongwook Cho
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Ji-Young Park
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Hyunjin Kim
- Center for Brain Function, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Eun-Bin Hong
- Center for Brain Function, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, 34126, Republic of Korea
| | - Euiheon Chung
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Hyoung-Ihl Kim
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea.
- Department of Neurosurgery, Presbyterian Medical Center, Jeonju, 54987, Republic of Korea.
| | - Min-Ho Nam
- Center for Brain Function, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
- Department of KHU-KIST Convergence Science and Technology, Kyung Hee University, Seoul, 02447, Republic of Korea.
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9
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Smith PA. BDNF in Neuropathic Pain; the Culprit that Cannot be Apprehended. Neuroscience 2024; 543:49-64. [PMID: 38417539 DOI: 10.1016/j.neuroscience.2024.02.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 02/20/2024] [Indexed: 03/01/2024]
Abstract
In males but not in females, brain derived neurotrophic factor (BDNF) plays an obligatory role in the onset and maintenance of neuropathic pain. Afferent terminals of injured peripheral nerves release colony stimulating factor (CSF-1) and other mediators into the dorsal horn. These transform the phenotype of dorsal horn microglia such that they express P2X4 purinoceptors. Activation of these receptors by neuron-derived ATP promotes BDNF release. This microglial-derived BDNF increases synaptic activation of excitatory dorsal horn neurons and decreases that of inhibitory neurons. It also alters the neuronal chloride gradient such the normal inhibitory effect of GABA is converted to excitation. By as yet undefined processes, this attenuated inhibition increases NMDA receptor function. BDNF also promotes the release of pro-inflammatory cytokines from astrocytes. All of these actions culminate in the increase dorsal horn excitability that underlies many forms of neuropathic pain. Peripheral nerve injury also alters excitability of structures in the thalamus, cortex and mesolimbic system that are responsible for pain perception and for the generation of co-morbidities such as anxiety and depression. The weight of evidence from male rodents suggests that this preferential modulation of excitably of supra-spinal pain processing structures also involves the action of microglial-derived BDNF. Possible mechanisms promoting the preferential release of BDNF in pain signaling structures are discussed. In females, invading T-lymphocytes increase dorsal horn excitability but it remains to be determined whether similar processes operate in supra-spinal structures. Despite its ubiquitous role in pain aetiology neither BDNF nor TrkB receptors represent potential therapeutic targets.
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Affiliation(s)
- Peter A Smith
- Neuroscience and Mental Health Institute and Department of Pharmacology, University of Alberta, Edmonton, Canada.
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10
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Ma Y, Chen J, Chen C, Wei B, Liu X. Suppression of HCN channels in the spinal dorsal horn restores KCC2 expression and attenuates diabetic neuropathic pain. Neurosci Lett 2024; 822:137626. [PMID: 38191090 DOI: 10.1016/j.neulet.2024.137626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/24/2023] [Accepted: 01/03/2024] [Indexed: 01/10/2024]
Abstract
Previous studies have shown that the hyperpolarized cyclic nucleotide gated (HCN) ion channels in the spinal dorsal horn (SDH) might be involved in the development of diabetic neuropathic pain (DNP). Additionally, other studies have shown that the decreased potassium-chloride cotransporter 2 (KCC2) expression in the SDH promotes pain hypersensitivity. Both HCN channels and KCC2 were highly expressed in spinal substantia gelatinosa neurons. However, whether the K+ efflux induced by the activation of HCN channels in DNP modulate KCC2 function and subsequently affect the role of γ-aminobutyric acid (GABA)/GABA-A receptors of neurons in the SDH remains to be clarified. The purpose of this work was to investigate the underlying mechanisms of KCC2 participating in HCN channels to promote DNP. Here, we found that the analgesic role of HCN channels blocker ZD7288 was associated with the up-regulated KCC2 expression and could be prevented by DIOA, a KCC2 blocker. Furthermore, the level of GABA in DNP rats significantly increased, which was decreased by ZD72288. Moreover, DIOA pretreatment could partly block the inhibitory effect of ZD7288 on the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) signaling activation of DNP rats. Finally, inhibition of cAMP-PKA signaling alleviated allodynia and elevated KCC2 expression in DNP rats. Altogether, this study reveals that the role of cAMP-PKA signaling-regulated HCN channels in DNP associated with decreased KCC2 expression in the spinal cord and altered GABA nature.
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Affiliation(s)
- Yanqiao Ma
- Department of Physiology, Zunyi Medical University, Zunyi 563000, China
| | - Ji Chen
- School of Pharmacy, Qingdao University, Qingdao 266000, China
| | - Chaodong Chen
- General Surgery, Fenggang County People's Hospital, Zunyi 563000, China
| | - Bangcong Wei
- Department of Pharmacy, Dushan County Mawei Central Hospital, Qiannan Buyi and Miao Autonomous Prefecture, 558000, China
| | - Xiaohong Liu
- Department of Physiology, Zunyi Medical University, Zunyi 563000, China.
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11
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Huang 黄玉莹 Y, Chen 陈红 H, Shao 邵建英 JY, Zhou 周京京 JJ, Chen 陈少瑞 SR, Pan 潘惠麟 HL. Constitutive KCC2 Cell- and Synapse-Specifically Regulates NMDA Receptor Activity in the Spinal Cord. J Neurosci 2024; 44:e1943232023. [PMID: 38124193 PMCID: PMC10860486 DOI: 10.1523/jneurosci.1943-23.2023] [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: 10/13/2023] [Revised: 11/20/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
K+-Cl- cotransporter-2 (KCC2) critically controls neuronal chloride homeostasis and maintains normal synaptic inhibition by GABA and glycine. Nerve injury diminishes synaptic inhibition in the spinal cord via KCC2 impairment. However, how KCC2 regulates nociceptive input to spinal excitatory and inhibitory neurons remains elusive. Here, we show that basal GABA reversal potentials were significantly more depolarized in vesicular GABA transporter (VGAT)-expressing inhibitory neurons than those in vesicular glutamate transporter-2 (VGluT2)-expressing excitatory neurons in spinal cords of male and female mice. Strikingly, inhibiting KCC2 with VU0463271 increased currents elicited by puff NMDA and the NMDAR-mediated frequency of mEPSCs in VGluT2, but not in VGAT, dorsal horn neurons. Notably, VU0463271 had no effect on EPSCs monosynaptically evoked from the dorsal root in VGluT2 neurons. Furthermore, VU0463271 augmented α2δ-1-NMDAR interactions and their protein levels in spinal cord synaptosomes. In Cacna2d1 KO mice, VU0463271 had no effect on puff NMDA currents or the mEPSC frequency in dorsal horn neurons. Disrupting α2δ-1-NMDAR interactions with α2δ-1 C-terminus mimicking peptide diminished VU0463271-induced potentiation in the mEPSC frequency and puff NMDA currents in VGluT2 neurons. Additionally, intrathecal injection of VU0463271 reduced mechanical and thermal thresholds in wild-type mice, but not in Cacna2d1 KO mice. VU0463271-induced pain hypersensitivity in mice was abrogated by co-treatment with the NMDAR antagonist, pregabalin (an α2δ-1 inhibitory ligand), or α2δ-1 C-terminus mimicking peptide. Our findings suggest that KCC2 controls presynaptic and postsynaptic NMDAR activity specifically in excitatory dorsal horn neurons. KCC2 impairment preferentially potentiates nociceptive transmission between spinal excitatory interneurons via α2δ-1-bound NMDARs.Significance statementImpaired function of potassium-chloride cotransporter-2 (KCC2), a key regulator of neuronal inhibition, in the spinal cord plays a major role in neuropathic pain. This study unveils that KCC2 controls spinal nociceptive synaptic strength via NMDA receptors in a cell type- and synapse type-specific manner. KCC2 inhibition preferentially augments presynaptic and postsynaptic NMDA receptor activity in spinal excitatory interneurons via α2δ-1 (previously known as a calcium channel subunit). Importantly, spinal KCC2 impairment triggers pain hypersensitivity through α2δ-1-coupled NMDA receptors. These findings pinpoint the cell and molecular substrates for the reciprocal relationship between spinal synaptic inhibition and excitation in chronic neuropathic pain. Targeting both KCC2 and α2δ-1–NMDA receptor complexes could be an effective strategy in managing neuropathic pain conditions.
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Affiliation(s)
- Yuying Huang 黄玉莹
- Department of Anesthesiology and Perioperative Medicine, Center for Neuroscience and Pain Research, The University of Texas MD Anderson Cancer Center, Houston 77030, Texas
| | - Hong Chen 陈红
- Department of Anesthesiology and Perioperative Medicine, Center for Neuroscience and Pain Research, The University of Texas MD Anderson Cancer Center, Houston 77030, Texas
| | - Jian-Ying Shao 邵建英
- Department of Anesthesiology and Perioperative Medicine, Center for Neuroscience and Pain Research, The University of Texas MD Anderson Cancer Center, Houston 77030, Texas
| | - Jing-Jing Zhou 周京京
- Department of Anesthesiology and Perioperative Medicine, Center for Neuroscience and Pain Research, The University of Texas MD Anderson Cancer Center, Houston 77030, Texas
| | - Shao-Rui Chen 陈少瑞
- Department of Anesthesiology and Perioperative Medicine, Center for Neuroscience and Pain Research, The University of Texas MD Anderson Cancer Center, Houston 77030, Texas
| | - Hui-Lin Pan 潘惠麟
- Department of Anesthesiology and Perioperative Medicine, Center for Neuroscience and Pain Research, The University of Texas MD Anderson Cancer Center, Houston 77030, Texas
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12
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Mahrous A, Birch D, Heckman CJ, Tysseling V. Muscle Spasms after Spinal Cord Injury Stem from Changes in Motoneuron Excitability and Synaptic Inhibition, Not Synaptic Excitation. J Neurosci 2024; 44:e1695232023. [PMID: 37949656 PMCID: PMC10851678 DOI: 10.1523/jneurosci.1695-23.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/24/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023] Open
Abstract
Muscle spasms are common in chronic spinal cord injury (SCI), posing challenges to rehabilitation and daily activities. Pharmacological management of spasms mostly targets suppression of excitatory inputs, an approach known to hinder motor recovery. To identify better targets, we investigated changes in inhibitory and excitatory synaptic inputs to motoneurons as well as motoneuron excitability in chronic SCI. We induced either a complete or incomplete SCI in adult mice of either sex and divided those with incomplete injury into low or high functional recovery groups. Their sacrocaudal spinal cords were then extracted and used to study plasticity below injury, with tissue from naive animals as a control. Electrical stimulation of the dorsal roots elicited spasm-like activity in preparations of chronic severe SCI but not in the control. To evaluate overall synaptic inhibition activated by sensory stimulation, we measured the rate-dependent depression of spinal root reflexes. We found inhibitory inputs to be impaired in chronic injury models. When synaptic inhibition was blocked pharmacologically, all preparations became clearly spastic, even the control. However, preparations with chronic injuries generated longer spasms than control. We then measured excitatory postsynaptic currents (EPSCs) in motoneurons during sensory-evoked spasms. The data showed no difference in the amplitude of EPSCs or their conductance among animal groups. Nonetheless, we found that motoneuron persistent inward currents activated by the EPSCs were increased in chronic SCI. These findings suggest that changes in motoneuron excitability and synaptic inhibition, rather than excitation, contribute to spasms and are better suited for more effective therapeutic interventions.Significance Statement Neural plasticity following spinal cord injury is crucial for recovery of motor function. Unfortunately, this process is blemished by maladaptive changes that can cause muscle spasms. Pharmacological alleviation of spasms without compromising the recovery of motor function has proven to be challenging. Here, we investigated changes in fundamental spinal mechanisms that can cause spasms post-injury. Our data suggest that the current management strategy for spasms is misdirected toward suppressing excitatory inputs, a mechanism that we found unaltered after injury, which can lead to further motor weakness. Instead, this study shows that more promising approaches might involve restoring synaptic inhibition or modulating motoneuron excitability.
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Affiliation(s)
| | - Derin Birch
- Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - C J Heckman
- Departments of Neuroscience
- Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - Vicki Tysseling
- Departments of Neuroscience
- Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
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13
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Smith PA. The Known Biology of Neuropathic Pain and Its Relevance to Pain Management. Can J Neurol Sci 2024; 51:32-39. [PMID: 36799022 DOI: 10.1017/cjn.2023.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Patients with neuropathic pain are heterogeneous in pathophysiology, etiology, and clinical presentation. Signs and symptoms are determined by the nature of the injury and factors such as genetics, sex, prior injury, age, culture, and environment. Basic science has provided general information about pain etiology by studying the consequences of peripheral injury in rodent models. This is associated with the release of inflammatory cytokines, chemokines, and growth factors that sensitize sensory nerve endings, alter gene expression, promote post-translational modification of proteins, and alter ion channel function. This leads to spontaneous activity in primary afferent neurons that is crucial for the onset and persistence of pain and the release of secondary mediators such as colony-stimulating factor 1 from primary afferent terminals. These promote the release of tertiary mediators such as brain-derived neurotrophic factor and interleukin-1β from microglia and astrocytes. Tertiary mediators facilitate the transmission of nociceptive information at the spinal, thalamic, and cortical levels. For the most part, these findings have failed to identify new therapeutic approaches. More recent basic science has better mirrored the clinical situation by addressing the pathophysiology associated with specific types of injury, refinement of methodology, and attention to various contributory factors such as sex. Improved quantification of sensory profiles in each patient and their distribution into defined clusters may improve translation between basic science and clinical practice. If such quantification can be traced back to cellular and molecular aspects of pathophysiology, this may lead to personalized medicine approaches that dictate a rational therapeutic approach for each individual.
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Affiliation(s)
- Peter A Smith
- Neuroscience and Mental Health Institute and Department of Pharmacology, University of Alberta, Edmonton, Canada
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14
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Tomita K, Kuwahara Y, Igarashi K, Kitanaka J, Kitanaka N, Takashi Y, Tanaka KI, Roudkenar MH, Roushandeh AM, Kurimasa A, Nishitani Y, Sato T. Therapeutic potential for KCC2-targeted neurological diseases. JAPANESE DENTAL SCIENCE REVIEW 2023; 59:431-438. [PMID: 38022385 PMCID: PMC10665825 DOI: 10.1016/j.jdsr.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 11/01/2023] [Accepted: 11/05/2023] [Indexed: 12/01/2023] Open
Abstract
Patients with neurological diseases, such as schizophrenia, tend to show low K+-Cl- co-transporter 2 (KCC2) levels in the brain. The cause of these diseases has been associated with stress and neuroinflammation. However, since the pathogenesis of these diseases is not yet fully investigated, drug therapy is still limited to symptomatic therapy. Targeting KCC2, which is mainly expressed in the brain, seems to be an appropriate approach in the treatment of these diseases. In this review, we aimed to discuss about stress and inflammation, KCC2 and Gamma-aminobutyric acid (GABA) function, diseases which decrease the KCC2 levels in the brain, factors that regulate KCC2 activity, and the possibility to overcome neuronal dysfunction targeting KCC2. We also aimed to discuss the relationships between neurological diseases and LPS caused by Porphyromonas gingivalis (P. g), which is a type of oral bacterium. Clinical trials on oxytocin, sirtuin 1 (SIRT1) activator, and transient receptor potential cation channel subfamily V Member 1 activator have been conducted to develop effective treatment methods. We believe that KCC2 modulators that regulate mitochondria, such as oxytocin, glycogen synthase kinase 3β (GSK3β), and SIRT1, can be potential targets for neurological diseases.
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Affiliation(s)
- Kazuo Tomita
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Division of Pharmacology, Department of Pharmacy, School of Pharmacy, Hyogo Medical University, Hyogo 650–8530, Japan
| | - Yoshikazu Kuwahara
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Division of Radiation Biology and Medicine, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Miyagi, 983-8536, Japan
| | - Kento Igarashi
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Division of Pharmacology, Department of Pharmacy, School of Pharmacy, Hyogo Medical University, Hyogo 650–8530, Japan
| | - Junichi Kitanaka
- Laboratory of Drug Addiction and Experimental Therapeutics, Schoolof Pharmacy, Hyogo Medical University, Hyogo 650-8530, Japan
| | - Nobue Kitanaka
- Laboratory of Drug Addiction and Experimental Therapeutics, Schoolof Pharmacy, Hyogo Medical University, Hyogo 650-8530, Japan
- Department of Pharmacology, School of Medicine, Hyogo Medical University, Hyogo 663-8501, Japan
| | - Yuko Takashi
- Department of Restorative Dentistry and Endodontology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
| | - Koh-ichi Tanaka
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Division of Pharmacology, Department of Pharmacy, School of Pharmacy, Hyogo Medical University, Hyogo 650–8530, Japan
| | - Mehryar Habibi Roudkenar
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
- Burn and Regenerative Medicine Research Center, Velayat Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht 41937–13194, Iran
| | - Amaneh Mohammadi Roushandeh
- Department of Anatomy, School of Biomedical Sciences, Medicine & Health, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Akihiro Kurimasa
- Division of Radiation Biology and Medicine, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Miyagi, 983-8536, Japan
| | - Yoshihiro Nishitani
- Department of Restorative Dentistry and Endodontology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
| | - Tomoaki Sato
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890–8544, Japan
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15
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Gilabert D, Duveau A, Carracedo S, Linck N, Langla A, Muramatsu R, Koch-Nolte F, Rassendren F, Grutter T, Fossat P, Boué-Grabot E, Ulmann L. Microglial P2X4 receptors are essential for spinal neurons hyperexcitability and tactile allodynia in male and female neuropathic mice. iScience 2023; 26:108110. [PMID: 37860691 PMCID: PMC10583052 DOI: 10.1016/j.isci.2023.108110] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/25/2023] [Accepted: 09/28/2023] [Indexed: 10/21/2023] Open
Abstract
In neuropathic pain, recent evidence has highlighted a sex-dependent role of the P2X4 receptor in spinal microglia in the development of tactile allodynia following nerve injury. Here, using internalization-defective P2X4mCherryIN knockin mice (P2X4KI), we demonstrate that increased cell surface expression of P2X4 induces hypersensitivity to mechanical stimulations and hyperexcitability in spinal cord neurons of both male and female naive mice. During neuropathy, both wild-type (WT) and P2X4KI mice of both sexes develop tactile allodynia accompanied by spinal neuron hyperexcitability. These responses are selectively associated with P2X4, as they are absent in global P2X4KO or myeloid-specific P2X4KO mice. We show that P2X4 is de novo expressed in reactive microglia in neuropathic WT and P2X4KI mice of both sexes and that tactile allodynia is relieved by pharmacological blockade of P2X4 or TrkB. These results show that the upregulation of P2X4 in microglia is crucial for neuropathic pain, regardless of sex.
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Affiliation(s)
- Damien Gilabert
- IGF, University Montpellier, CNRS, INSERM, F-34094 Montpellier, France
- LabEx Ion Channel Science and Therapeutics, Montpellier, France
| | - Alexia Duveau
- University Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Sara Carracedo
- University Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Nathalie Linck
- IGF, University Montpellier, CNRS, INSERM, F-34094 Montpellier, France
- LabEx Ion Channel Science and Therapeutics, Montpellier, France
| | - Adeline Langla
- University Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Rieko Muramatsu
- Department of Molecular Pharmacology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan
| | - Friedrich Koch-Nolte
- Institute of Immunology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - François Rassendren
- IGF, University Montpellier, CNRS, INSERM, F-34094 Montpellier, France
- LabEx Ion Channel Science and Therapeutics, Montpellier, France
| | - Thomas Grutter
- University of Strasbourg, CNRS, CAMB UMR 7199, F-67000 Strasbourg, France
| | - Pascal Fossat
- University Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Eric Boué-Grabot
- University Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Lauriane Ulmann
- IGF, University Montpellier, CNRS, INSERM, F-34094 Montpellier, France
- LabEx Ion Channel Science and Therapeutics, Montpellier, France
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16
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Hayashi K, Lesnak JB, Plumb AN, Janowski AJ, Smith AF, Hill JK, Sluka KA. Brain-derived neurotrophic factor contributes to activity-induced muscle pain in male but not female mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.31.565022. [PMID: 37961342 PMCID: PMC10635076 DOI: 10.1101/2023.10.31.565022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Activity-induced muscle pain increases release of interleukin-1β (IL-1β) in muscle macrophages and the development of pain is prevented by blockade of IL-1β. Brain derived neurotrophic factor (BDNF) is released from sensory neurons in response to IL-1β and mediates both inflammatory and neuropathic pain. Thus, we hypothesized that metabolites released during fatiguing muscle contractions activate macrophages to release IL-1β, which subsequently activate sensory neurons to secrete BDNF. To test this hypothesis, we used an animal model of activity-induced pain induced by repeated intramuscular acidic saline injections combined with fatiguing muscle contractions. Intrathecal or intramuscular injection of inhibitors of BDNF-Tropomyosin receptor kinase B (TrkB) signaling, ANA-12 or TrkB-Fc, reduced the decrease in muscle withdrawal thresholds in male, but not in female, mice when given before or 24hr after, but not 1 week after induction of the model. BDNF messenger ribonucleic acid (mRNA) was significantly increased in L4-L6 dorsal root ganglion (DRG), but not the spinal dorsal horn or gastrocnemius muscle, 24hr after induction of the model in either male or female mice. No changes in TrkB mRNA or p75 neurotrophin receptor mRNA were observed. BDNF protein expression via immunohistochemistry was significantly increased in L4-L6 spinal dorsal horn and retrogradely labelled muscle afferent DRG neurons, at 24hr after induction of the model in both sexes. In cultured DRG, fatigue metabolites combined with IL-1β significantly increased BDNF expression in both sexes. In summary, fatigue metabolites release, combined with IL-1β, BDNF from primary DRG neurons and contribute to activity-induced muscle pain only in males, while there were no sex differences in the changes in expression observed in BDNF.
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Affiliation(s)
- Kazuhiro Hayashi
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Joseph B. Lesnak
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Ashley N. Plumb
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Adam J. Janowski
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Angela F. Smith
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Joslyn K. Hill
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
| | - Kathleen A. Sluka
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA
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17
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Ghazisaeidi S, Muley MM, Tu Y, Finn DP, Kolahdouzan M, Pitcher GM, Kim D, Sengar AS, Ramani AK, Brudno M, Salter MW. Conserved transcriptional programming across sex and species after peripheral nerve injury predicts treatments for neuropathic pain. Br J Pharmacol 2023; 180:2822-2836. [PMID: 37336547 DOI: 10.1111/bph.16168] [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: 09/02/2022] [Revised: 04/28/2023] [Accepted: 06/03/2023] [Indexed: 06/21/2023] Open
Abstract
BACKGROUND AND PURPOSE Chronic pain is a devastating problem affecting one in five individuals around the globe, with neuropathic pain the most debilitating and poorly treated type of chronic pain. Advances in transcriptomics have contributed to cataloguing diverse cellular pathways and transcriptomic alterations in response to peripheral nerve injury but have focused on phenomenology and classifying transcriptomic responses. EXPERIMENTAL APPROACH To identifying new types of pain-relieving agents, we compared transcriptional reprogramming changes in the dorsal spinal cord after peripheral nerve injury cross-sex and cross-species, and imputed commonalities, as well as differences in cellular pathways and gene regulation. KEY RESULTS We identified 93 transcripts in the dorsal horn that were increased by peripheral nerve injury in male and female mice and rats. Following gene ontology and transcription factor analyses, we constructed a pain interactome for the proteins encoded by the differentially expressed genes, discovering new, conserved signalling nodes. We investigated the interactome with the Drug-Gene database to predict FDA-approved medications that may modulate key nodes within the network. The top hit from the analysis was fostamatinib, the molecular target of which is the non-receptor spleen associated tyrosine kinase (Syk), which our analysis had identified as a key node in the interactome. We found that intrathecally administrating the active metabolite of fostamatinib, R406 and another Syk inhibitor P505-15, significantly reversed pain hypersensitivity in both sexes. CONCLUSIONS AND IMPLICATIONS Thus, we have identified and shown the efficacy of an agent that could not have been previously predicted to have analgesic properties.
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Affiliation(s)
- Shahrzad Ghazisaeidi
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Program in Neuroscience & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Milind M Muley
- Program in Neuroscience & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - YuShan Tu
- Program in Neuroscience & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - David P Finn
- Pharmacology and Therapeutics, School of Medicine, Centre for Pain Research, University of Galway, Galway, Ireland
| | - Mahshad Kolahdouzan
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Program in Neuroscience & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Graham M Pitcher
- Program in Neuroscience & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Doyeon Kim
- Program in Neuroscience & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ameet S Sengar
- Program in Neuroscience & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Arun K Ramani
- Centre for Computational Medicine, The Hospital for Sick Children, Toronto, Canada
| | - Michael Brudno
- Centre for Computational Medicine, The Hospital for Sick Children, Toronto, Canada
- Department of Computer Science, University of Toronto, Toronto, Canada
- Techna Institute, University Health Network, Toronto, Canada
- Vector Institute for Artificial Intelligence, Toronto, Canada
| | - Michael W Salter
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Program in Neuroscience & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
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18
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Gilbert JE, Zhang T, Esteller R, Grill WM. Network model of nociceptive processing in the superficial spinal dorsal horn reveals mechanisms of hyperalgesia, allodynia, and spinal cord stimulation. J Neurophysiol 2023; 130:1103-1117. [PMID: 37727912 DOI: 10.1152/jn.00186.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 09/13/2023] [Accepted: 09/15/2023] [Indexed: 09/21/2023] Open
Abstract
The spinal dorsal horn (DH) processes sensory information and plays a key role in transmitting nociception to supraspinal centers. Loss of DH inhibition during neuropathic pain unmasks a pathway from nonnociceptive Aβ-afferent inputs to superficial dorsal horn (SDH) nociceptive-specific (NS) projection neurons, and this change may contribute to hyperalgesia and allodynia. We developed and validated a computational model of SDH neuronal circuitry that links nonnociceptive Aβ-afferent inputs in lamina II/III to a NS projection neuron in lamina I via a network of excitatory interneurons. The excitatory pathway and the NS projection neuron were in turn gated by inhibitory interneurons with connections based on prior patch-clamp recordings. Changing synaptic weights in the computational model to replicate neuropathic pain states unmasked a low-threshold excitatory pathway to NS neurons similar to experimental recordings. Spinal cord stimulation (SCS) is an effective therapy for neuropathic pain, and accumulating experimental evidence indicates that NS neurons in the SDH also respond to SCS. Accounting for these responses may inform therapeutic improvements, and we quantified responses to SCS in the SDH network model and examined the role of different modes of inhibitory control in modulating NS neuron responses to SCS. We combined the SDH network model with a previously published model of the deep dorsal horn (DDH) and identified optimal stimulation frequencies across different neuropathic pain conditions. Finally, we found that SCS-generated inhibition did not completely suppress model NS activity during simulated pinch inputs, providing an explanation of why SCS does not eliminate acute pain.NEW & NOTEWORTHY Chronic pain is a severe public health problem that reduces the quality of life for those affected and exacts an enormous socio-economic burden worldwide. Spinal cord stimulation (SCS) is an effective treatment for chronic pain, but SCS efficacy has not significantly improved over time, in part because the mechanisms of action remain unclear. Most preclinical studies investigating pain and SCS mechanisms have focused on the responses of deep dorsal horn (DDH) neurons, but neural networks in the superficial dorsal horn (SDH) are also important for processing nociceptive information. This work synthesizes heterogeneous experimental recordings from the SDH into a computational model that replicates experimental responses and that can be used to quantify neuronal responses to SCS under neuropathic pain conditions.
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Affiliation(s)
- John E Gilbert
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States
| | - Tianhe Zhang
- Neuromodulation Research and Advanced Concepts, Boston Scientific Neuromodulation, Valencia, California, United States
| | - Rosana Esteller
- Neuromodulation Research and Advanced Concepts, Boston Scientific Neuromodulation, Valencia, California, United States
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina, United States
- Department of Neurobiology, Duke University School of Medicine, Durham, North Carolina, United States
- Department of Neurosurgery, Duke University School of Medicine, Durham, North Carolina, United States
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19
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Parameshwarappa V, Siponen M, Watabe I, Karkaba A, Galazyuk A, Noreña A. Noise-Induced Hearing Loss Alters Potassium-Chloride CoTransporter KCC2 and GABA Inhibition in the auditory centers. RESEARCH SQUARE 2023:rs.3.rs-3389804. [PMID: 37886592 PMCID: PMC10602088 DOI: 10.21203/rs.3.rs-3389804/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Homeostatic plasticity, the ability of neurons to maintain their averaged activity constant around a set point value, is thought to account for the central hyperactivity after hearing loss. Here, we investigated the putative role of GABAergic neurotransmission in this mechanism after a noise-induced hearing loss larger than 50 dB in high frequencies in guinea pigs. The effect of GABAergic inhibition is linked to the normal functioning of K+-Cl- co-transporter isoform 2 (KCC2) which maintains a low intracellular concentration of chloride. The expression of membrane KCC2 were investigated before after noise trauma in the ventral and dorsal cochlear nucleus (VCN and DCN, respectively) and in the inferior colliculus (IC). Moreover, the effect of gabazine (GBZ), a GABA antagonist, was also studied on the neural activity in IC. We show that KCC2 is downregulated in VCN, DCN and IC 3 days after noise trauma, and in DCN and IC 30 days after the trauma. As expected, GBZ application in the IC of control animals resulted in an increase of spontaneous and stimulus-evoked activity. In the noise exposed animals, on the other hand, GBZ application decreased the stimulus-evoked activity in IC neurons. The functional implications of these central changes are discussed.
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Affiliation(s)
| | - Marina Siponen
- Centre National de la Recherche Scientifique, Aix- Marseille University
| | - Isabelle Watabe
- Centre National de la Recherche Scientifique, Aix- Marseille University
| | - Alaa Karkaba
- Centre National de la Recherche Scientifique, Aix- Marseille University
| | | | - Arnaud Noreña
- Centre National de la Recherche Scientifique, Aix- Marseille University
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20
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Smith PA. Neuropathic pain; what we know and what we should do about it. FRONTIERS IN PAIN RESEARCH 2023; 4:1220034. [PMID: 37810432 PMCID: PMC10559888 DOI: 10.3389/fpain.2023.1220034] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023] Open
Abstract
Neuropathic pain can result from injury to, or disease of the nervous system. It is notoriously difficult to treat. Peripheral nerve injury promotes Schwann cell activation and invasion of immunocompetent cells into the site of injury, spinal cord and higher sensory structures such as thalamus and cingulate and sensory cortices. Various cytokines, chemokines, growth factors, monoamines and neuropeptides effect two-way signalling between neurons, glia and immune cells. This promotes sustained hyperexcitability and spontaneous activity in primary afferents that is crucial for onset and persistence of pain as well as misprocessing of sensory information in the spinal cord and supraspinal structures. Much of the current understanding of pain aetiology and identification of drug targets derives from studies of the consequences of peripheral nerve injury in rodent models. Although a vast amount of information has been forthcoming, the translation of this information into the clinical arena has been minimal. Few, if any, major therapeutic approaches have appeared since the mid 1990's. This may reflect failure to recognise differences in pain processing in males vs. females, differences in cellular responses to different types of injury and differences in pain processing in humans vs. animals. Basic science and clinical approaches which seek to bridge this knowledge gap include better assessment of pain in animal models, use of pain models which better emulate human disease, and stratification of human pain phenotypes according to quantitative assessment of signs and symptoms of disease. This can lead to more personalized and effective treatments for individual patients. Significance statement: There is an urgent need to find new treatments for neuropathic pain. Although classical animal models have revealed essential features of pain aetiology such as peripheral and central sensitization and some of the molecular and cellular mechanisms involved, they do not adequately model the multiplicity of disease states or injuries that may bring forth neuropathic pain in the clinic. This review seeks to integrate information from the multiplicity of disciplines that seek to understand neuropathic pain; including immunology, cell biology, electrophysiology and biophysics, anatomy, cell biology, neurology, molecular biology, pharmacology and behavioral science. Beyond this, it underlines ongoing refinements in basic science and clinical practice that will engender improved approaches to pain management.
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Affiliation(s)
- Peter A. Smith
- Neuroscience and Mental Health Institute and Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
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21
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Byvaltcev E, Behbood M, Schleimer JH, Gensch T, Semyanov A, Schreiber S, Strauss U. KCC2 reverse mode helps to clear postsynaptically released potassium at glutamatergic synapses. Cell Rep 2023; 42:112934. [PMID: 37537840 PMCID: PMC10480490 DOI: 10.1016/j.celrep.2023.112934] [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: 05/21/2023] [Revised: 07/09/2023] [Accepted: 07/18/2023] [Indexed: 08/05/2023] Open
Abstract
Extracellular potassium [K+]o elevation during synaptic activity retrogradely modifies presynaptic release and astrocytic uptake of glutamate. Hence, local K+ clearance and replenishment mechanisms are crucial regulators of glutamatergic transmission and plasticity. Based on recordings of astrocytic inward rectifier potassium current IKir and K+-sensitive electrodes as sensors of [K+]o as well as on in silico modeling, we demonstrate that the neuronal K+-Cl- co-transporter KCC2 clears local perisynaptic [K+]o during synaptic excitation by operating in an activity-dependent reversed mode. In reverse mode, KCC2 replenishes K+ in dendritic spines and complements clearance of [K+]o, therewith attenuating presynaptic glutamate release and shortening LTP. We thus demonstrate a physiological role of KCC2 in neuron-glial interactions and regulation of synaptic signaling and plasticity through the uptake of postsynaptically released K+.
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Affiliation(s)
- Egor Byvaltcev
- Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Mahraz Behbood
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Jan-Hendrik Schleimer
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Thomas Gensch
- Institute of Biological Information Processing 1 (IBI-1, Molecular and Cellular Physiology), Forschungszentrum Jülich, Wilhem-Jonen Straße, 52428 Jülich, Germany
| | - Alexey Semyanov
- Department of Physiology, Jiaxing University College of Medicine, Zhejiang Pro, Jiaxing 314033, China
| | - Susanne Schreiber
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Ulf Strauss
- Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany.
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22
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Tsuda M, Masuda T, Kohno K. Microglial diversity in neuropathic pain. Trends Neurosci 2023:S0166-2236(23)00124-8. [PMID: 37244781 DOI: 10.1016/j.tins.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/17/2023] [Accepted: 05/02/2023] [Indexed: 05/29/2023]
Abstract
Microglia play pivotal roles in controlling CNS functions in diverse physiological and pathological contexts, including neuropathic pain, a chronic pain condition caused by lesions or diseases of the somatosensory nervous system. In this review article, we summarize evidence primarily from basic research on the role of microglia in the development and remission of neuropathic pain. The identification of a subset of microglia that emerged after pain development and that was necessary for remission of neuropathic pain highlights the highly divergent and dynamic nature of microglia in the course of neuropathic pain. Understanding microglial diversity in terms of gene expression, physiological states, and functional roles could lead to new strategies that aid in the diagnosis and management of neuropathic pain, and that may not have been anticipated from the viewpoint of targeting all microglia uniformly.
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Affiliation(s)
- Makoto Tsuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan; Kyushu University Institute for Advanced Study, Fukuoka, Japan.
| | - Takahiro Masuda
- Division of Molecular Neuroimmunology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Keita Kohno
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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23
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Ghazisaeidi S, Muley MM, Salter MW. Neuropathic Pain: Mechanisms, Sex Differences, and Potential Therapies for a Global Problem. Annu Rev Pharmacol Toxicol 2023; 63:565-583. [PMID: 36662582 DOI: 10.1146/annurev-pharmtox-051421-112259] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The study of chronic pain continues to generate ever-increasing numbers of publications, but safe and efficacious treatments for chronic pain remain elusive. Recognition of sex-specific mechanisms underlying chronic pain has resulted in a surge of studies that include both sexes. A predominant focus has been on identifying sex differences, yet many newly identified cellular mechanisms and alterations in gene expression are conserved between the sexes. Here we review sex differences and similarities in cellular and molecular signals that drive the generation and resolution of neuropathic pain. The mix of differences and similarities reflects degeneracy in peripheral and central signaling processes by which neurons, immune cells, and glia codependently drive pain hypersensitivity. Recent findings identifying critical signaling nodes foreshadow the development of rationally designed, broadly applicable analgesic strategies. However, the paucity of effective, safe pain treatments compels targeted therapies as well to increase therapeutic options that help reduce the global burden of suffering.
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Affiliation(s)
- Shahrzad Ghazisaeidi
- Program in Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada;
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- University of Toronto Centre for the Study of Pain, Toronto, Ontario, Canada
| | - Milind M Muley
- Program in Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada;
- University of Toronto Centre for the Study of Pain, Toronto, Ontario, Canada
| | - Michael W Salter
- Program in Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada;
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- University of Toronto Centre for the Study of Pain, Toronto, Ontario, Canada
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24
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Kreis A, Issa F, Yerna X, Jabbour C, Schakman O, de Clippele M, Tajeddine N, Pierrot N, Octave JN, Gualdani R, Gailly P. Conditional deletion of KCC2 impairs synaptic plasticity and both spatial and nonspatial memory. Front Mol Neurosci 2023; 16:1081657. [PMID: 37168681 PMCID: PMC10164999 DOI: 10.3389/fnmol.2023.1081657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 03/31/2023] [Indexed: 05/13/2023] Open
Abstract
The postsynaptic inhibition through GABAA receptors (GABAAR) relies on two mechanisms, a shunting effect due to an increase in the postsynaptic membrane conductance and, in mature neurons, a hyperpolarization effect due to an entry of chloride into postsynaptic neurons. The second effect requires the action of the K+-Cl- cotransporter KCC2 which extrudes Cl- from the cell and maintains its cytosolic concentration very low. Neuronal chloride equilibrium seems to be dysregulated in several neurological and psychiatric conditions such as epilepsy, anxiety, schizophrenia, Down syndrome, or Alzheimer's disease. In the present study, we used the KCC2 Cre-lox knockdown system to investigate the role of KCC2 in synaptic plasticity and memory formation in adult mice. Tamoxifen-induced conditional deletion of KCC2 in glutamatergic neurons of the forebrain was performed at 3 months of age and resulted in spatial and nonspatial learning impairment. On brain slices, the stimulation of Schaffer collaterals by a theta burst induced long-term potentiation (LTP). The lack of KCC2 did not affect potentiation of field excitatory postsynaptic potentials (fEPSP) measured in the stratum radiatum (dendrites) but increased population spike (PS) amplitudes measured in the CA1 somatic layer, suggesting a reinforcement of the EPSP-PS potentiation, i.e., an increased ability of EPSPs to generate action potentials. At the cellular level, KCC2 deletion induced a positive shift in the reversal potential of GABAAR-driven Cl- currents (EGABA), suggesting an intracellular accumulation of chloride subsequent to the downregulation of KCC2. After treatment with bumetanide, an antagonist of the Na+-K+-Cl- cotransporter NKCC1, spatial memory impairment, chloride accumulation, and EPSP-PS potentiation were rescued in mice lacking KCC2. The presented results emphasize the importance of chloride equilibrium and GABA-inhibiting ability in synaptic plasticity and memory formation.
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25
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Yeo M, Zhang Q, Ding L, Shen X, Chen Y, Liedtke W. Spinal cord dorsal horn sensory gate in preclinical models of chemotherapy-induced painful neuropathy and contact dermatitis chronic itch becomes less leaky with Kcc2 gene expression-enhancing treatments. Front Mol Neurosci 2022; 15:911606. [PMID: 36504679 PMCID: PMC9731339 DOI: 10.3389/fnmol.2022.911606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 10/05/2022] [Indexed: 11/25/2022] Open
Abstract
Low intraneuronal chloride in spinal cord dorsal horn (SCDH) pain relay neurons is of critical relevance for physiological transmission of primary sensory afferents because low intraneuronal chloride dictates GABA-ergic and glycin-ergic neurotransmission to be inhibitory. If neuronal chloride rises to unphysiological levels, the primary sensory gate in the spinal cord dorsal horn becomes corrupted, with resulting behavioral hallmarks of hypersensitivity and allodynia, for example in pathological pain. Low chloride in spinal cord dorsal horn neurons relies on the robust gene expression of Kcc2 and sustained transporter function of the KCC2 chloride-extruding electroneutral transporter. Based on a recent report where we characterized the GSK3-inhibitory small molecule, kenpaullone, as a Kcc2 gene expression-enhancer that potently repaired diminished Kcc2 expression and KCC2 transporter function in SCDH pain relay neurons, we extend our recent findings by reporting (i) effective pain control in a preclinical model of taxol-induced painful peripheral neuropathy that was accomplished by topical application of a TRPV4/TRPA1 dual-inhibitory compound (compound 16-8), and was associated with the repair of diminished Kcc2 gene expression in the SCDH; and (ii) potent functioning of kenpaullone as an antipruritic in a DNFB contact dermatitis preclinical model. These observations suggest that effective peripheral treatment of chemotherapy-induced painful peripheral neuropathy impacts the pain-transmitting neural circuit in the SCDH in a beneficial manner by enhancing Kcc2 gene expression, and that chronic pruritus might be relayed in the primary sensory gate of the spinal cord, following similar principles as pathological pain, specifically relating to the critical functioning of Kcc2 gene expression and the KCC2 transporter function.
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Affiliation(s)
- Michele Yeo
- Departments of Neurosurgery, Duke University Medical Center, Durham, NC, United States
| | - Qiaojuan Zhang
- Departments of Neurology, Duke University Medical Center, Durham, NC, United States
| | - LeAnne Ding
- Departments of Neurology, Duke University Medical Center, Durham, NC, United States
| | - Xiangjun Shen
- Departments of Neurology, Duke University Medical Center, Durham, NC, United States
| | - Yong Chen
- Departments of Neurology, Duke University Medical Center, Durham, NC, United States,*Correspondence: Yong Chen
| | - Wolfgang Liedtke
- Departments of Neurology, Duke University Medical Center, Durham, NC, United States,Wolfgang Liedtke
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26
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Da Vitoria Lobo ME, Weir N, Hardowar L, Al Ojaimi Y, Madden R, Gibson A, Bestall SM, Hirashima M, Schaffer CB, Donaldson LF, Bates DO, Hulse RP. Hypoxia-induced carbonic anhydrase mediated dorsal horn neuron activation and induction of neuropathic pain. Pain 2022; 163:2264-2279. [PMID: 35353768 PMCID: PMC9578530 DOI: 10.1097/j.pain.0000000000002627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 02/17/2022] [Accepted: 02/23/2022] [Indexed: 11/27/2022]
Abstract
ABSTRACT Neuropathic pain, such as that seen in diabetes mellitus, results in part from central sensitisation in the dorsal horn. However, the mechanisms responsible for such sensitisation remain unclear. There is evidence that disturbances in the integrity of the spinal vascular network can be causative factors in the development of neuropathic pain. Here we show that reduced blood flow and vascularity of the dorsal horn leads to the onset of neuropathic pain. Using rodent models (type 1 diabetes and an inducible endothelial-specific vascular endothelial growth factor receptor 2 knockout mouse) that result in degeneration of the endothelium in the dorsal horn, we show that spinal cord vasculopathy results in nociceptive behavioural hypersensitivity. This also results in increased hypoxia in dorsal horn neurons, depicted by increased expression of hypoxia markers such as hypoxia inducible factor 1α, glucose transporter 3, and carbonic anhydrase 7. Furthermore, inducing hypoxia through intrathecal delivery of dimethyloxalylglycine leads to the activation of dorsal horn neurons as well as mechanical and thermal hypersensitivity. This shows that hypoxic signalling induced by reduced vascularity results in increased hypersensitivity and pain. Inhibition of carbonic anhydrase activity, through intraperitoneal injection of acetazolamide, inhibited hypoxia-induced pain behaviours. This investigation demonstrates that induction of a hypoxic microenvironment in the dorsal horn, as occurs in diabetes, is an integral process by which neurons are activated to initiate neuropathic pain states. This leads to the conjecture that reversing hypoxia by improving spinal cord microvascular blood flow could reverse or prevent neuropathic pain.
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Affiliation(s)
- Marlene E. Da Vitoria Lobo
- Division of Cancer and Stem Cells, School of Medicine, Biodiscovery Institute, University of Nottingham, Nottingham, United Kingdom
| | - Nick Weir
- School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Lydia Hardowar
- School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Yara Al Ojaimi
- School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Ryan Madden
- Division of Cancer and Stem Cells, School of Medicine, Biodiscovery Institute, University of Nottingham, Nottingham, United Kingdom
| | - Alex Gibson
- Division of Cancer and Stem Cells, School of Medicine, Biodiscovery Institute, University of Nottingham, Nottingham, United Kingdom
| | - Samuel M. Bestall
- Pain Centre Versus Arthritis and School of Life Sciences, The Medical School QMC, University of Nottingham, Nottingham, United Kingdom
| | - Masanori Hirashima
- Division of Pharmacology, Niigata University Graduate School of Medical and Dental Sciences, Japan
| | - Chris B. Schaffer
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, United States
| | - Lucy F. Donaldson
- Pain Centre Versus Arthritis and School of Life Sciences, The Medical School QMC, University of Nottingham, Nottingham, United Kingdom
| | - David O. Bates
- Division of Cancer and Stem Cells, School of Medicine, Biodiscovery Institute, University of Nottingham, Nottingham, United Kingdom
- Centre of Membrane and Protein and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, United Kingdom
| | - Richard Philip Hulse
- Division of Cancer and Stem Cells, School of Medicine, Biodiscovery Institute, University of Nottingham, Nottingham, United Kingdom
- School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
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27
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Hudson KE, Grau JW. Ionic Plasticity: Common Mechanistic Underpinnings of Pathology in Spinal Cord Injury and the Brain. Cells 2022; 11:cells11182910. [PMID: 36139484 PMCID: PMC9496934 DOI: 10.3390/cells11182910] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 11/16/2022] Open
Abstract
The neurotransmitter GABA is normally characterized as having an inhibitory effect on neural activity in the adult central nervous system (CNS), which quells over-excitation and limits neural plasticity. Spinal cord injury (SCI) can bring about a modification that weakens the inhibitory effect of GABA in the central gray caudal to injury. This change is linked to the downregulation of the potassium/chloride cotransporter (KCC2) and the consequent rise in intracellular Cl- in the postsynaptic neuron. As the intracellular concentration increases, the inward flow of Cl- through an ionotropic GABA-A receptor is reduced, which decreases its hyperpolarizing (inhibitory) effect, a modulatory effect known as ionic plasticity. The loss of GABA-dependent inhibition enables a state of over-excitation within the spinal cord that fosters aberrant motor activity (spasticity) and chronic pain. A downregulation of KCC2 also contributes to the development of a number of brain-dependent pathologies linked to states of neural over-excitation, including epilepsy, addiction, and developmental disorders, along with other diseases such as hypertension, asthma, and irritable bowel syndrome. Pharmacological treatments that target ionic plasticity have been shown to bring therapeutic benefits.
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Affiliation(s)
- Kelsey E. Hudson
- Neuroscience, Texas A&M University, College Station, TX 77843, USA
- Correspondence:
| | - James W. Grau
- Psychological & Brain Sciences, Texas A&M University, College Station, TX 77843, USA
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28
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Aby F, Lorenzo LE, Grivet Z, Bouali-Benazzouz R, Martin H, Valerio S, Whitestone S, Isabel D, Idi W, Bouchatta O, De Deurwaerdere P, Godin AG, Herry C, Fioramonti X, Landry M, De Koninck Y, Fossat P. Switch of serotonergic descending inhibition into facilitation by a spinal chloride imbalance in neuropathic pain. SCIENCE ADVANCES 2022; 8:eabo0689. [PMID: 35895817 PMCID: PMC9328683 DOI: 10.1126/sciadv.abo0689] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
Descending control from the brain to the spinal cord shapes our pain experience, ranging from powerful analgesia to extreme sensitivity. Increasing evidence from both preclinical and clinical studies points to an imbalance toward descending facilitation as a substrate of pathological pain, but the underlying mechanisms remain unknown. We used an optogenetic approach to manipulate serotonin (5-HT) neurons of the nucleus raphe magnus that project to the dorsal horn of the spinal cord. We found that 5-HT neurons exert an analgesic action in naïve mice that becomes proalgesic in an experimental model of neuropathic pain. We show that spinal KCC2 hypofunction turns this descending inhibitory control into paradoxical facilitation; KCC2 enhancers restored 5-HT-mediated descending inhibition and analgesia. Last, combining selective serotonin reuptake inhibitors (SSRIs) with a KCC2 enhancer yields effective analgesia against nerve injury-induced pain hypersensitivity. This uncovers a previously unidentified therapeutic path for SSRIs against neuropathic pain.
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Affiliation(s)
- Franck Aby
- Université de Bordeaux, Bordeaux, France
- Institut des maladies neurodégénératives (IMN), CNRS UMR 5293, Bordeaux, France
| | - Louis-Etienne Lorenzo
- CERVO Brain Research Center, Université Laval, Québec City, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, Canada
| | - Zoé Grivet
- Université de Bordeaux, Bordeaux, France
- Institut des maladies neurodégénératives (IMN), CNRS UMR 5293, Bordeaux, France
| | - Rabia Bouali-Benazzouz
- Université de Bordeaux, Bordeaux, France
- Institut des maladies neurodégénératives (IMN), CNRS UMR 5293, Bordeaux, France
| | - Hugo Martin
- NutriNeuro, UMR, INRAe, 1286 Bordeaux, France
| | | | - Sara Whitestone
- Université de Bordeaux, Bordeaux, France
- Institut des maladies neurodégénératives (IMN), CNRS UMR 5293, Bordeaux, France
| | - Dominique Isabel
- CERVO Brain Research Center, Université Laval, Québec City, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, Canada
| | - Walid Idi
- Université de Bordeaux, Bordeaux, France
- Institut des maladies neurodégénératives (IMN), CNRS UMR 5293, Bordeaux, France
| | - Otmane Bouchatta
- Université de Bordeaux, Bordeaux, France
- Institut des maladies neurodégénératives (IMN), CNRS UMR 5293, Bordeaux, France
- CERVO Brain Research Center, Université Laval, Québec City, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, Canada
- NutriNeuro, UMR, INRAe, 1286 Bordeaux, France
- Aquineuro, SA, Bordeaux, France
- Université Cadi Ayyad, Marrakech, Morocco
| | - Philippe De Deurwaerdere
- Université de Bordeaux, Bordeaux, France
- Institut des neurosciences cognitives et intégratives d’aquitaine (INCIA) CNRS UMR 5287, Bordeaux, France
| | - Antoine G. Godin
- CERVO Brain Research Center, Université Laval, Québec City, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, Canada
| | - Cyril Herry
- Neurocentre Magendie, INSERM, U862, Bordeaux, France
| | | | - Marc Landry
- Université de Bordeaux, Bordeaux, France
- Institut des maladies neurodégénératives (IMN), CNRS UMR 5293, Bordeaux, France
| | - Yves De Koninck
- CERVO Brain Research Center, Université Laval, Québec City, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, Canada
| | - Pascal Fossat
- Université de Bordeaux, Bordeaux, France
- Institut des maladies neurodégénératives (IMN), CNRS UMR 5293, Bordeaux, France
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29
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Tansley S, Gu N, Guzmán AU, Cai W, Wong C, Lister K, Muñoz-Pino E, Yousefpour N, Roome RB, Heal J, Wu N, Castonguay A, Lean G, Muir EM, Kania A, Prager-Khoutorsky M, Zhang J, Gkogkas CG, Fawcett JW, Diatchenko L, Ribeiro-da-Silva A, De Koninck Y, Mogil JS, Khoutorsky A. Microglia-mediated degradation of perineuronal nets promotes pain. Science 2022; 377:80-86. [PMID: 35617374 DOI: 10.1126/science.abl6773] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Activation of microglia in the spinal cord dorsal horn following peripheral nerve injury contributes to the development of pain hypersensitivity. How activated microglia selectively enhance the activity of spinal nociceptive circuits is not well understood. We discovered that following peripheral nerve injury, microglia degrade extracellular matrix structures, perineuronal nets (PNNs), in lamina I of the spinal cord dorsal horn. Lamina I PNNs selectively enwrap spinoparabrachial projection neurons, which integrate nociceptive information in the spinal cord and convey it to supraspinal brain regions to induce pain sensation. Degradation of PNNs by microglia enhances the activity of projection neurons and induces pain-related behaviors. Thus, nerve injury-induced degradation of PNNs is a mechanism by which microglia selectively augment the output of spinal nociceptive circuits and cause pain hypersensitivity.
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Affiliation(s)
- Shannon Tansley
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada.,Department of Psychology, Faculty of Science, McGill University, Montreal, Quebec, Canada
| | - Ning Gu
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
| | - Alba Ureña Guzmán
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
| | - Weihua Cai
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
| | - Calvin Wong
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
| | - Kevin Lister
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
| | - Einer Muñoz-Pino
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec, QC, Canada
| | - Noosha Yousefpour
- Departement of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - R Brian Roome
- Institut de Recherches Cliniques de Montreal (IRCM), Montreal, QC, Canada
| | - Jordyn Heal
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
| | - Neil Wu
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
| | - Annie Castonguay
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec, QC, Canada
| | - Graham Lean
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Elizabeth M Muir
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Artur Kania
- Institut de Recherches Cliniques de Montreal (IRCM), Montreal, QC, Canada.,Departement of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | | | - Ji Zhang
- Department of Neurology and Neurosurgery, McGill University, Montreal, Québec, Canada.,Faculty of Dental Medicine and Oral Health Sciences, Montreal, Quebec, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Christos G Gkogkas
- Biomedical Research Institute, Foundation for Research and Technology-Hellas, University Campus, 45110 Ioannina, Greece
| | - James W Fawcett
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Centre for Reconstructive Neuroscience, Institute for Experimental Medicine CAS, Prague, Czech Republic
| | - Luda Diatchenko
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada.,Faculty of Dental Medicine and Oral Health Sciences, Montreal, Quebec, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Alfredo Ribeiro-da-Silva
- Departement of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada.,Departement of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Yves De Koninck
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec, QC, Canada.,Departement of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Jeffrey S Mogil
- Department of Psychology, Faculty of Science, McGill University, Montreal, Quebec, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Arkady Khoutorsky
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada.,Faculty of Dental Medicine and Oral Health Sciences, Montreal, Quebec, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
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Liedtke W. Long March Toward Safe and Effective Analgesia by Enhancing Gene Expression of Kcc2: First Steps Taken. Front Mol Neurosci 2022; 15:865600. [PMID: 35645734 PMCID: PMC9137411 DOI: 10.3389/fnmol.2022.865600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/08/2022] [Indexed: 11/15/2022] Open
Abstract
Low intraneuronal chloride in spinal cord dorsal horn pain relay neurons is critical for physiologic transmission of primary pain afferents because low intraneuronal chloride dictates whether GABA-ergic and glycin-ergic neurotransmission is inhibitory. If the neuronal chloride elevates to pathologic levels, then spinal cord primary pain relay becomes leaky and exhibits the behavioral hallmarks of pathologic pain, namely hypersensitivity and allodynia. Low chloride in spinal cord dorsal horn neurons is maintained by proper gene expression of Kcc2 and sustained physiologic function of the KCC2 chloride extruding electroneutral transporter. Peripheral nerve injury and other forms of neural injury evoke greatly diminished Kcc2 gene expression and subsequent corruption of inhibitory neurotransmission in the spinal cord dorsal horn, thus causing derailment of the gate function for pain. Here I review key discoveries that have helped us understand these fundamentals, and focus on recent insights relating to the discovery of Kcc2 gene expression enhancing compounds via compound screens in neurons. One such study characterized the kinase inhibitor, kenpaullone, more in-depth, revealing its function as a robust and long-lasting analgesic in preclinical models of nerve injury and cancer bone pain, also elucidating its mechanism of action via GSK3β inhibition, diminishing delta-catenin phosphorylation, and facilitating its nuclear transfer and subsequent enhancement of Kcc2 gene expression by de-repressing Kaiso epigenetic transcriptional regulator. Future directions re Kcc2 gene expression enhancement are discussed, namely combination with other analgesics and analgesic methods, such as spinal cord stimulation and electroacupuncture, gene therapy, and leveraging Kcc2 gene expression-enhancing nanomaterials.
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Medlock L, Sekiguchi K, Hong S, Dura-Bernal S, Lytton WW, Prescott SA. Multiscale Computer Model of the Spinal Dorsal Horn Reveals Changes in Network Processing Associated with Chronic Pain. J Neurosci 2022; 42:3133-3149. [PMID: 35232767 PMCID: PMC8996343 DOI: 10.1523/jneurosci.1199-21.2022] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 11/21/2022] Open
Abstract
Pain-related sensory input is processed in the spinal dorsal horn (SDH) before being relayed to the brain. That processing profoundly influences whether stimuli are correctly or incorrectly perceived as painful. Significant advances have been made in identifying the types of excitatory and inhibitory neurons that comprise the SDH, and there is some information about how neuron types are connected, but it remains unclear how the overall circuit processes sensory input or how that processing is disrupted under chronic pain conditions. To explore SDH function, we developed a computational model of the circuit that is tightly constrained by experimental data. Our model comprises conductance-based neuron models that reproduce the characteristic firing patterns of spinal neurons. Excitatory and inhibitory neuron populations, defined by their expression of genetic markers, spiking pattern, or morphology, were synaptically connected according to available qualitative data. Using a genetic algorithm, synaptic weights were tuned to reproduce projection neuron firing rates (model output) based on primary afferent firing rates (model input) across a range of mechanical stimulus intensities. Disparate synaptic weight combinations could produce equivalent circuit function, revealing degeneracy that may underlie heterogeneous responses of different circuits to perturbations or pathologic insults. To validate our model, we verified that it responded to the reduction of inhibition (i.e., disinhibition) and ablation of specific neuron types in a manner consistent with experiments. Thus validated, our model offers a valuable resource for interpreting experimental results and testing hypotheses in silico to plan experiments for examining normal and pathologic SDH circuit function.SIGNIFICANCE STATEMENT We developed a multiscale computer model of the posterior part of spinal cord gray matter (spinal dorsal horn), which is involved in perceiving touch and pain. The model reproduces several experimental observations and makes predictions about how specific types of spinal neurons and synapses influence projection neurons that send information to the brain. Misfiring of these projection neurons can produce anomalous sensations associated with chronic pain. Our computer model will not only assist in planning future experiments, but will also be useful for developing new pharmacotherapy for chronic pain disorders, connecting the effect of drugs acting at the molecular scale with emergent properties of neurons and circuits that shape the pain experience.
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Affiliation(s)
- Laura Medlock
- Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Kazutaka Sekiguchi
- Drug Developmental Research Laboratory, Shionogi Pharmaceutical Research Center, Toyonaka, Osaka 561-0825, Japan
- State University of New York Downstate Health Science University, Brooklyn, New York 11203
| | - Sungho Hong
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan
| | - Salvador Dura-Bernal
- State University of New York Downstate Health Science University, Brooklyn, New York 11203
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York 10962
| | - William W Lytton
- State University of New York Downstate Health Science University, Brooklyn, New York 11203
- Kings County Hospital, Brooklyn, New York 11207
| | - Steven A Prescott
- Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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32
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Dedek A, Hildebrand ME. Advances and Barriers in Understanding Presynaptic N-Methyl-D-Aspartate Receptors in Spinal Pain Processing. Front Mol Neurosci 2022; 15:864502. [PMID: 35431805 PMCID: PMC9008455 DOI: 10.3389/fnmol.2022.864502] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/04/2022] [Indexed: 12/16/2022] Open
Abstract
For decades, N-methyl-D-aspartate (NMDA) receptors have been known to play a critical role in the modulation of both acute and chronic pain. Of particular interest are NMDA receptors expressed in the superficial dorsal horn (SDH) of the spinal cord, which houses the nociceptive processing circuits of the spinal cord. In the SDH, NMDA receptors undergo potentiation and increases in the trafficking of receptors to the synapse, both of which contribute to increases in excitability and plastic increases in nociceptive output from the SDH to the brain. Research efforts have primarily focused on postsynaptic NMDA receptors, despite findings that presynaptic NMDA receptors can undergo similar plastic changes to their postsynaptic counterparts. Recent technological advances have been pivotal in the discovery of mechanisms of plastic changes in presynaptic NMDA receptors within the SDH. Here, we highlight these recent advances in the understanding of presynaptic NMDA receptor physiology and their modulation in models of chronic pain. We discuss the role of specific NMDA receptor subunits in presynaptic membranes of nociceptive afferents and local SDH interneurons, including their modulation across pain modalities. Furthermore, we discuss how barriers such as lack of sex-inclusive research and differences in neurodevelopmental timepoints have complicated investigations into the roles of NMDA receptors in pathological pain states. A more complete understanding of presynaptic NMDA receptor function and modulation across pain states is needed to shed light on potential new therapeutic treatments for chronic pain.
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Affiliation(s)
- Annemarie Dedek
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
- Neuroscience Department, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Michael E. Hildebrand
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
- Neuroscience Department, Ottawa Hospital Research Institute, Ottawa, ON, Canada
- *Correspondence: Michael E. Hildebrand,
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Ba X, Ran C, Guo W, Guo J, Zeng Q, Liu T, Sun W, Xiao L, Xiong D, Huang Y, Jiang C, Hao Y. Three-Day Continuous Oxytocin Infusion Attenuates Thermal and Mechanical Nociception by Rescuing Neuronal Chloride Homeostasis via Upregulation KCC2 Expression and Function. Front Pharmacol 2022; 13:845018. [PMID: 35401174 PMCID: PMC8988046 DOI: 10.3389/fphar.2022.845018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
Oxytocin (OT) and its receptor are promising targets for the treatment and prevention of the neuropathic pain. In the present study, we compared the effects of a single and continuous intrathecal infusion of OT on nerve injury-induced neuropathic pain behaviours in mice and further explore the mechanisms underlying their analgesic properties. We found that three days of continuous intrathecal OT infusion alleviated subsequent pain behaviours for 14 days, whereas a single OT injection induced a transient analgesia for 30 min, suggesting that only continuous intrathecal OT attenuated the establishment and development of neuropathic pain behaviours. Supporting this behavioural finding, continuous intrathecal infusion, but not short-term incubation of OT, reversed the nerve injury-induced depolarizing shift in Cl- reversal potential via restoring the function and expression of spinal K+-Cl- cotransporter 2 (KCC2), which may be caused by OT-induced enhancement of GABA inhibitory transmission. This result suggests that only continuous use of OT may reverse the pathological changes caused by nerve injury, thereby mechanistically blocking the establishment and development of pain. These findings provide novel evidence relevant for advancing understanding of the effects of continuous OT administration on the pathophysiology of pain.
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Affiliation(s)
- Xiyuan Ba
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Shenzhen Nanshan People’s Hospital, Shenzhen, China
| | - Chenqiu Ran
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen, China
| | - Wenjun Guo
- Department of Pain Medicine, Shenzhen, China
| | - Jing Guo
- Department of Endocrinology and Metabolism, Shenzhen University General Hospital and Shenzhen University Academy of Clinical Medical Sciences, Shenzhen University, Shenzhen, China
| | - Qian Zeng
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Shenzhen Nanshan People’s Hospital, Shenzhen, China
| | - Tao Liu
- Department of Pediatrics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Wuping Sun
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Shenzhen Nanshan People’s Hospital, Shenzhen, China
| | - Lizu Xiao
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Shenzhen Nanshan People’s Hospital, Shenzhen, China
| | - Donglin Xiong
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Shenzhen Nanshan People’s Hospital, Shenzhen, China
| | - Yelan Huang
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen, China
| | - Changyu Jiang
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Shenzhen Nanshan People’s Hospital, Shenzhen, China
| | - Yue Hao
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen, China
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Dedek A, Xu J, Lorenzo LÉ, Godin AG, Kandegedara CM, Glavina G, Landrigan JA, Lombroso PJ, De Koninck Y, Tsai EC, Hildebrand ME. Sexual dimorphism in a neuronal mechanism of spinal hyperexcitability across rodent and human models of pathological pain. Brain 2022; 145:1124-1138. [PMID: 35323848 PMCID: PMC9050559 DOI: 10.1093/brain/awab408] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/03/2021] [Accepted: 10/15/2021] [Indexed: 12/23/2022] Open
Abstract
The prevalence and severity of many chronic pain syndromes differ across sex, and recent studies have identified differences in immune signalling within spinal nociceptive circuits as a potential mediator. Although it has been proposed that sex-specific pain mechanisms converge once they reach neurons within the superficial dorsal horn, direct investigations using rodent and human preclinical pain models have been lacking. Here, we discovered that in the Freund’s adjuvant in vivo model of inflammatory pain, where both male and female rats display tactile allodynia, a pathological coupling between KCC2-dependent disinhibition and N-methyl-D-aspartate receptor (NMDAR) potentiation within superficial dorsal horn neurons was observed in male but not female rats. Unlike males, the neuroimmune mediator brain-derived neurotrophic factor (BDNF) failed to downregulate inhibitory signalling elements (KCC2 and STEP61) and upregulate excitatory elements (pFyn, GluN2B and pGluN2B) in female rats, resulting in no effect of ex vivo brain-derived neurotrophic factor on synaptic NMDAR responses in female lamina I neurons. Importantly, this sex difference in spinal pain processing was conserved from rodents to humans. As in rodents, ex vivo spinal treatment with BDNF downregulated markers of disinhibition and upregulated markers of facilitated excitation in superficial dorsal horn neurons from male but not female human organ donors. Ovariectomy in female rats recapitulated the male pathological pain neuronal phenotype, with BDNF driving a coupling between disinhibition and NMDAR potentiation in adult lamina I neurons following the prepubescent elimination of sex hormones in females. This discovery of sexual dimorphism in a central neuronal mechanism of chronic pain across species provides a foundational step towards a better understanding and treatment for pain in both sexes.
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Affiliation(s)
- Annemarie Dedek
- Department of Neuroscience, Carleton University, K1S 5B6 Ontario, Canada.,Neuroscience Program, Ottawa Hospital Research Institute, K1Y 4M9 Ontario, Canada
| | - Jian Xu
- Child Study Center, Yale University School of Medicine, New Haven, CT 06519, USA
| | | | - Antoine G Godin
- CERVO Brain Research Centre, Quebec Mental Health Institute, Quebec G1E 1T2, Canada.,Department of Psychiatry and Neuroscience, Université Laval, Quebec G1V 0A6, Canada
| | - Chaya M Kandegedara
- Department of Neuroscience, Carleton University, K1S 5B6 Ontario, Canada.,Neuroscience Program, Ottawa Hospital Research Institute, K1Y 4M9 Ontario, Canada
| | - Geneviève Glavina
- CERVO Brain Research Centre, Quebec Mental Health Institute, Quebec G1E 1T2, Canada
| | | | - Paul J Lombroso
- Child Study Center, Yale University School of Medicine, New Haven, CT 06519, USA
| | - Yves De Koninck
- CERVO Brain Research Centre, Quebec Mental Health Institute, Quebec G1E 1T2, Canada.,Department of Psychiatry and Neuroscience, Université Laval, Quebec G1V 0A6, Canada
| | - Eve C Tsai
- Neuroscience Program, Ottawa Hospital Research Institute, K1Y 4M9 Ontario, Canada.,Brain and Mind Research Institute, University of Ottawa, Ontario K1N 6N5, Canada.,Department of Surgery, Division of Neurosurgery, The Ottawa Hospital, Ontario K1Y 4E9, Canada
| | - Michael E Hildebrand
- Department of Neuroscience, Carleton University, K1S 5B6 Ontario, Canada.,Neuroscience Program, Ottawa Hospital Research Institute, K1Y 4M9 Ontario, Canada
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Boakye PA, Tang SJ, Smith PA. Mediators of Neuropathic Pain; Focus on Spinal Microglia, CSF-1, BDNF, CCL21, TNF-α, Wnt Ligands, and Interleukin 1β. FRONTIERS IN PAIN RESEARCH 2022; 2:698157. [PMID: 35295524 PMCID: PMC8915739 DOI: 10.3389/fpain.2021.698157] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/14/2021] [Indexed: 01/04/2023] Open
Abstract
Intractable neuropathic pain is a frequent consequence of nerve injury or disease. When peripheral nerves are injured, damaged axons undergo Wallerian degeneration. Schwann cells, mast cells, fibroblasts, keratinocytes and epithelial cells are activated leading to the generation of an “inflammatory soup” containing cytokines, chemokines and growth factors. These primary mediators sensitize sensory nerve endings, attract macrophages, neutrophils and lymphocytes, alter gene expression, promote post-translational modification of proteins, and alter ion channel function in primary afferent neurons. This leads to increased excitability and spontaneous activity and the generation of secondary mediators including colony stimulating factor 1 (CSF-1), chemokine C-C motif ligand 21 (CCL-21), Wnt3a, and Wnt5a. Release of these mediators from primary afferent neurons alters the properties of spinal microglial cells causing them to release tertiary mediators, in many situations via ATP-dependent mechanisms. Tertiary mediators such as BDNF, tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and other Wnt ligands facilitate the generation and transmission of nociceptive information by increasing excitatory glutamatergic transmission and attenuating inhibitory GABA and glycinergic transmission in the spinal dorsal horn. This review focusses on activation of microglia by secondary mediators, release of tertiary mediators from microglia and a description of their actions in the spinal dorsal horn. Attention is drawn to the substantial differences in the precise roles of various mediators in males compared to females. At least 25 different mediators have been identified but the similarity of their actions at sensory nerve endings, in the dorsal root ganglia and in the spinal cord means there is considerable redundancy in the available mechanisms. Despite this, behavioral studies show that interruption of the actions of any single mediator can relieve signs of pain in experimental animals. We draw attention this paradox. It is difficult to explain how inactivation of one mediator can relieve pain when so many parallel pathways are available.
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Affiliation(s)
- Paul A Boakye
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Shao-Jun Tang
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Peter A Smith
- Neuroscience and Mental Health Institute and Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
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Abstract
We aimed to investigate a sexually dimorphic role of calcitonin gene-related peptide (CGRP) in rodent models of pain. Based on findings in migraine where CGRP has a preferential pain-promoting effect in female rodents, we hypothesized that CGRP antagonists and antibodies would attenuate pain sensitization more efficaciously in female than male mice and rats. In hyperalgesic priming induced by activation of interleukin 6 signaling, CGRP receptor antagonists olcegepant and CGRP8-37 both given intrathecally, blocked, and reversed hyperalgesic priming only in females. A monoclonal antibody against CGRP, given systemically, blocked priming specifically in female rodents but failed to reverse it. In the spared nerve injury model, there was a transient effect of both CGRP antagonists, given intrathecally, on mechanical hypersensitivity in female mice only. Consistent with these findings, intrathecally applied CGRP caused a long-lasting, dose-dependent mechanical hypersensitivity in female mice but more transient effects in males. This CGRP-induced mechanical hypersensitivity was reversed by olcegepant and the KCC2 enhancer CLP257, suggesting a role for anionic plasticity in the dorsal horn in the pain-promoting effects of CGRP in females. In spinal dorsal horn slices, CGRP shifted GABAA reversal potentials to significantly more positive values, but, again, only in female mice. Therefore, CGRP may regulate KCC2 expression and/or activity downstream of CGRP receptors specifically in females. However, KCC2 hypofunction promotes mechanical pain hypersensitivity in both sexes because CLP257 alleviated hyperalgesic priming in male and female mice. We conclude that CGRP promotes pain plasticity in female rodents but has a limited impact in males.SIGNIFICANCE STATEMENT The majority of patients impacted by chronic pain are women. Mechanistic studies in rodents are creating a clear picture that molecular events promoting chronic pain are different in male and female animals. We sought to build on evidence showing that CGRP is a more potent and efficacious promoter of headache in female than in male rodents. To test this, we used hyperalgesic priming and the spared nerve injury neuropathic pain models in mice. Our findings show a clear sex dimorphism wherein CGRP promotes pain in female but not male mice, likely via a centrally mediated mechanism of action. Our work suggests that CGRP receptor antagonists could be tested for efficacy in women for a broader variety of pain conditions.
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Halievski K, Sengar AS, Hicks J, Haight J, Salter MW, Steinberg BE. Cholinergic modulation is independent of T lymphocytes in a mouse model of neuropathic pain. Mol Pain 2022; 18:17448069221076634. [PMID: 35174761 PMCID: PMC8859656 DOI: 10.1177/17448069221076634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
T lymphocytes are increasingly implicated in pain signaling. A subset of T lymphocytes, termed TChAT, express the rate-limiting enzyme for acetylcholine (ACh) production, choline acetyltransferase (ChAT), and mediate numerous physiological functions. Given that cholinergic signaling has long been known to modulate pain processing and is the basis for several analgesics used clinically, we asked whether TChAT could be the intersection between T lymphocyte and cholinergic mediation of pain signaling. In this study, we used a mouse gene knockout strategy to ablate ChAT specifically from T lymphocytes and examined the development and expression of mechanical and thermal hypersensitivity in a spared nerve injury (SNI) mouse model of neuropathic pain. We found that mice with ChAT knockout in T cells (floxed Chat plus CD4-Cre recombinase) did not differ from control mice with intact ChAT (floxed Chat, but no Cre recombinase) in their expression of mechanical sensitivity before or after injury. Similarly, thermal sensitivity was unaffected after injury, with control mice expressing similar patterns of thermal preference to mice whose T cells do not express ChAT. Our experiments demonstrate that cholinergic signaling initiated by T lymphocytes neither dampens nor exacerbates the expression of mechanical or thermal sensitivity in neuropathic mice. Thus, while both cholinergic signaling and T lymphocytes have established roles in modulating pain phenotypes, it is not cholinergic signaling initiated by T lymphocytes that drive this. Our findings will help to narrow in on which aspects of T-cell modulation may prove useful as therapies.
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Affiliation(s)
| | | | - Janice Hicks
- 7979The Hospital for Sick Children, Toronto, ON, Canada
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Esu KD, Bakare AO, Owoyele BV. Effects of co-administration of vitamin E and lithium chloride on chronic constriction injury-induced neuropathy in male Wistar rats: Focus on antioxidant and anti-inflammatory mechanisms. Pain Pract 2022; 22:148-158. [PMID: 34351685 DOI: 10.1111/papr.13064] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 07/21/2021] [Accepted: 07/29/2021] [Indexed: 12/25/2022]
Abstract
OBJECTIVES This study investigated the antinociceptive effects of co-administration of lithium chloride (LiCl) and vitamin E (Vit E) on chronic constriction injury (CCI)-induced peripheral neuropathy in male Wistar rats. It further explored the anti-inflammatory and neuroprotective properties of LiCl and Vit E, which may be complementary to the antinociceptive effects of the two substances. METHODS Thirty-six male Wistar rats, 190.00 ± 10.00 g of body weight were randomly assigned to 6 experimental groups and administered with normal saline, Vit E, LiCl, or their combination, once daily for 21 days. CCI was used to induce neuropathic pain (NP) and mechanical allodynia was assessed using von Frey filaments and pinprick test. Open field maze (OFM) was used to assess the exploratory behavior. Biochemical parameters were assessed in the dorsal root ganglion after 21 days of treatment. RESULTS Mechanical allodynia was developed in rats following CCI. Co-administration of LiCl and Vit E synergistically reduced mechanical hyperalgesia in rats which were significantly different compared with the single administration of either Vit E or LiCl. Combined doses of Vit E and LiCl significantly increases the explorative behavior in the OFM. CCI increased malondialdehyde (MDA), tumor necrotic factor-alpha (TNF-α), calcitonin gene-related polypeptide, calcium ion (Ca2+ ), and reduced superoxide dismutase (SOD) activities. Co-administration of LiCl and Vit E significantly reduced MDA, TNF-α, but increased SOD compared with ligated control. DISCUSSION The findings revealed that the synergistic effects of the co-administration of Vit E and LiCl in ameliorating NP are mediated by their anti-inflammatory and antioxidant properties.
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Affiliation(s)
- Kingsley Dominic Esu
- Neuroscience and Inflammation Unit, Department of Physiology, University of Ilorin, Ilorin, Nigeria
| | - Ahmed Olalekan Bakare
- Neuroscience and Inflammation Unit, Department of Physiology, University of Ilorin, Ilorin, Nigeria
| | - Bamidele Victor Owoyele
- Neuroscience and Inflammation Unit, Department of Physiology, University of Ilorin, Ilorin, Nigeria
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Time-Dependent Changes in Protein Composition of Medial Prefrontal Cortex in Rats with Neuropathic Pain. Int J Mol Sci 2022; 23:ijms23020955. [PMID: 35055141 PMCID: PMC8781622 DOI: 10.3390/ijms23020955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/10/2022] [Accepted: 01/14/2022] [Indexed: 01/03/2023] Open
Abstract
Chronic pain is associated with time-dependent structural and functional reorganization of the prefrontal cortex that may reflect adaptive pain compensatory and/or maladaptive pain-promoting mechanisms. However, the molecular underpinnings of these changes and whether there are time-dependent relationships to pain progression are not well characterized. In this study, we analyzed protein composition in the medial prefrontal cortex (mPFC) of rats at two timepoints after spinal nerve ligation (SNL) using two-dimensional gel electrophoresis (2D-ELFO) and liquid chromatography with tandem mass spectrometry (LC–MS/MS). SNL, but not sham-operated, rats developed persistent tactile allodynia and thermal hyperalgesia, confirming the presence of experimental neuropathic pain. Two weeks after SNL (early timepoint), we identified 11 proteins involved in signal transduction, protein transport, cell homeostasis, metabolism, and apoptosis, as well as heat-shock proteins and chaperones that were upregulated by more than 1.5-fold compared to the sham-operated rats. Interestingly, there were only four significantly altered proteins identified at 8 weeks after SNL (late timepoint). These findings demonstrate extensive time-dependent modifications of protein expression in the rat mPFC under a chronic neuropathic pain state that might underlie the evolution of chronic pain characterized by early pain-compensatory and later aberrant mechanisms.
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van den Hoogen NJ, Harding EK, Davidson CED, Trang T. Cannabinoids in Chronic Pain: Therapeutic Potential Through Microglia Modulation. Front Neural Circuits 2022; 15:816747. [PMID: 35069129 PMCID: PMC8777271 DOI: 10.3389/fncir.2021.816747] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/17/2021] [Indexed: 12/16/2022] Open
Abstract
Chronic pain is a complex sensory, cognitive, and emotional experience that imposes a great personal, psychological, and socioeconomic burden on patients. An estimated 1.5 billion people worldwide are afflicted with chronic pain, which is often difficult to treat and may be resistant to the potent pain-relieving effects of opioid analgesics. Attention has therefore focused on advancing new pain therapies directed at the cannabinoid system because of its key role in pain modulation. Endocannabinoids and exogenous cannabinoids exert their actions primarily through Gi/o-protein coupled cannabinoid CB1 and CB2 receptors expressed throughout the nervous system. CB1 receptors are found at key nodes along the pain pathway and their activity gates both the sensory and affective components of pain. CB2 receptors are typically expressed at low levels on microglia, astrocytes, and peripheral immune cells. In chronic pain states, there is a marked increase in CB2 expression which modulates the activity of these central and peripheral immune cells with important consequences for the surrounding pain circuitry. Growing evidence indicate that interventions targeting CB1 or CB2 receptors improve pain outcomes in a variety of preclinical pain models. In this mini-review, we will highlight recent advances in understanding how cannabinoids modulate microglia function and its implications for cannabinoid-mediated analgesia, focusing on microglia-neuron interactions within the spinal nociceptive circuitry.
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Affiliation(s)
- Nynke J. van den Hoogen
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
- Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Erika K. Harding
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
- Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Chloé E. D. Davidson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
- Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Tuan Trang
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
- Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- *Correspondence: Tuan Trang
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Gao Y, Zhan W, Jin Y, Chen X, Cai J, Zhou X, Huang X, Zhao Q, Wang W, Sun J. KCC2 receptor upregulation potentiates antinociceptive effect of GABAAR agonist on remifentanil-induced hyperalgesia. Mol Pain 2022; 18:17448069221082880. [PMID: 35352582 PMCID: PMC8972932 DOI: 10.1177/17448069221082880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
GABAergic system disinhibition played an important role in the pathogenesis of remifentanil-induced hyperalgesia (RIH). K+-Cl--cotransporter-2 (KCC2) has the potential to enhance the strength of GABAergic signaling function. However, few reports have focused on the additive analgesic effect of KCC2 enhancer and GABAA receptor agonist on the spinal dorsal horn. Therefore, we evaluated the role of GABA type A receptor (GABAAR) agonist (muscimol), KCC2 enhancer (CLP257) in remifentanil-induced hyperalgesia, as well as GABA and KCC2 receptors responses in the dorsal spinal horn. Remifentanil started to reduce paw withdrawal mechanical thresholds at postoperative 4 h and lasted to 72 h. The RIH associated decreases in spinal GABA release was transient. The amount of spinal GABA transmitter by microdialysis was observed to be decreased at the beginning and reached bottom at 150 min, then returned to the baseline level at 330 min. The synthesis and transportation of GABA transmitter were inhibited, characterized as spinal GAD67 and GAT1 downregulation after the establishment of RIH model. The effect of RIH on GABA receptor downregulation was linked to the reduced expression of spinal KCC2 receptor. This decrease in KCC2 expression has coincided with an early loss of GABA inhibition. KCC2 enhancer, which is reported to lead to a reduction in intracellular Cl−, can enhance GABA-mediated inhibitory function. Both muscimol and CLP257 could dose-dependently inhibit mechanical hypersensitivity caused by remifentanil-induced downregulation of GABAAα2R and KCC2, respectively. Compared with muscimol acting alone, the joint action of CLP257 and muscimol showed a higher pain threshold and less c-fos expression via upregulation of KCC2 and GABAAα2R. Taken together, these findings suggested that the RIH was initiated by decreased GABA release. Downregulation of GABAAα2R and KCC2 receptor contributed to spinally mediated hyperalgesia in RIH. KCC2 enhancer was proved to potentiate antinociceptive effect of GABAAR agonist in RIH.
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Affiliation(s)
- Yuan Gao
- Department of Anesthesiology, First Affiliated Hospital, 89657Wenzhou Medical University, Wenzhou, Zhejiang, China.,Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Wenqiang Zhan
- Department of Anesthesiology, 159388Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yushi Jin
- Department of Anesthesiology, First Affiliated Hospital, 89657Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaodan Chen
- Department of Operating Room Nursing, First Affiliated Hospital, 89657Wenzhou Medical University, Wenzhou, China
| | - Jinxia Cai
- Department of Anesthesiology, First Affiliated Hospital, 89657Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaotian Zhou
- Department of Anesthesiology, First Affiliated Hospital, 89657Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xinyi Huang
- Department of Anesthesiology, First Affiliated Hospital, 89657Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qimin Zhao
- Department of Anesthesiology, First Affiliated Hospital, 89657Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Weijian Wang
- Department of Anesthesiology, First Affiliated Hospital, 89657Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jiehao Sun
- Department of Anesthesiology, First Affiliated Hospital, 89657Wenzhou Medical University, Wenzhou, Zhejiang, China
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Asraf H, Bogdanovic M, Gottesman N, Sekler I, Aizenman E, Hershfinkel M. SNAP23 regulates KCC2 membrane insertion and activity following mZnR/GPR39 activation in hippocampal neurons. iScience 2022; 25:103751. [PMID: 35118363 PMCID: PMC8800107 DOI: 10.1016/j.isci.2022.103751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/25/2021] [Accepted: 01/06/2022] [Indexed: 11/23/2022] Open
Abstract
Modulation of the neuronal K+/Cl− cotransporter 2 (KCC2) activity, which mediates Cl− export, is critical to neuronal function. Here, we demonstrate that KCC2 interacts with the SNARE protein synaptosome-associated protein 23, SNAP23, an essential component of membrane insertion machinery. Using KCC2 truncated mutants, we show that KCC2 C-terminal domain is essential for membrane targeting and SNAP23-dependent upregulation of KCC2 activity triggered by activation of the Zn2+-sensitive receptor mZnR/GPR39 in HEK293 cells. Expression of SNAP23 phosphorylation-insensitive mutants or inhibition of its upstream activator IκB kinase (IKK) prevents mZnR/GPR39 upregulation of KCC2 activity in mouse hippocampal neurons. We further find that SNAP23 interacts with Syntaxin 1A and KCC2, and that all three proteins exhibit increased membrane insertion following mZnR/GPR39 activation in neurons. Our results elucidate a G-protein-coupled receptor-dependent pathway for regulation of KCC activity, mediated via interaction with SNARE proteins. Neuronal K+/Cl− cotransporter 2 (KCC2) is regulated via interaction with SNAP23 Zn2+ enhances interaction and membrane insertion of SNAP23, Syntaxin 1A, and KCC2 Zn2+-dependent mZnR/GPR39 regulation of KCC2 requires SNAP23 phosphorylation Epithelial KCC3 regulation by ZnR/GPR39 also requires SNAP23
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Sullivan BJ, Kipnis PA, Carter BM, Shao LR, Kadam SD. Targeting ischemia-induced KCC2 hypofunction rescues refractory neonatal seizures and mitigates epileptogenesis in a mouse model. Sci Signal 2021; 14:eabg2648. [PMID: 34752143 DOI: 10.1126/scisignal.abg2648] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Brennan J Sullivan
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
| | - Pavel A Kipnis
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
| | - Brandon M Carter
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
| | - Li-Rong Shao
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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44
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Yeo M, Chen Y, Jiang C, Chen G, Wang K, Chandra S, Bortsov A, Lioudyno M, Zeng Q, Wang P, Wang Z, Busciglio J, Ji RR, Liedtke W. Repurposing cancer drugs identifies kenpaullone which ameliorates pathologic pain in preclinical models via normalization of inhibitory neurotransmission. Nat Commun 2021; 12:6208. [PMID: 34707084 PMCID: PMC8551327 DOI: 10.1038/s41467-021-26270-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
Inhibitory GABA-ergic neurotransmission is fundamental for the adult vertebrate central nervous system and requires low chloride concentration in neurons, maintained by KCC2, a neuroprotective ion transporter that extrudes intracellular neuronal chloride. To identify Kcc2 gene expression‑enhancing compounds, we screened 1057 cell growth-regulating compounds in cultured primary cortical neurons. We identified kenpaullone (KP), which enhanced Kcc2/KCC2 expression and function in cultured rodent and human neurons by inhibiting GSK3ß. KP effectively reduced pathologic pain-like behavior in mouse models of nerve injury and bone cancer. In a nerve-injury pain model, KP restored Kcc2 expression and GABA-evoked chloride reversal potential in the spinal cord dorsal horn. Delta-catenin, a phosphorylation-target of GSK3ß in neurons, activated the Kcc2 promoter via KAISO transcription factor. Transient spinal over-expression of delta-catenin mimicked KP analgesia. Our findings of a newly repurposed compound and a novel, genetically-encoded mechanism that each enhance Kcc2 gene expression enable us to re-normalize disrupted inhibitory neurotransmission through genetic re-programming.
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Affiliation(s)
- Michele Yeo
- Department of Neurology, Duke University Medical Center, Durham, NC, USA.
| | - Yong Chen
- Department of Neurology, Duke University Medical Center, Durham, NC, USA.
| | - Changyu Jiang
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Gang Chen
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Kaiyuan Wang
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Sharat Chandra
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Andrey Bortsov
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Maria Lioudyno
- Department of Neurobiology & Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA, USA
| | - Qian Zeng
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Peng Wang
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Zilong Wang
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Jorge Busciglio
- Department of Neurobiology & Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA, USA
| | - Ru-Rong Ji
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.
| | - Wolfgang Liedtke
- Department of Neurology, Duke University Medical Center, Durham, NC, USA.
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.
- Duke Neurology Clinics for Headache, Head-Pain and Trigeminal Sensory Disorders, Duke University Medical Center, Durham, NC, USA.
- Duke Anesthesiology Clinics for Innovative Pain Therapy, Duke University Medical Center, Durham, NC, USA.
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Savardi A, Borgogno M, De Vivo M, Cancedda L. Pharmacological tools to target NKCC1 in brain disorders. Trends Pharmacol Sci 2021; 42:1009-1034. [PMID: 34620512 DOI: 10.1016/j.tips.2021.09.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/27/2021] [Accepted: 09/08/2021] [Indexed: 02/06/2023]
Abstract
The chloride importer NKCC1 and the chloride exporter KCC2 are key regulators of neuronal chloride concentration. A defective NKCC1/KCC2 expression ratio is associated with several brain disorders. Preclinical/clinical studies have shown that NKCC1 inhibition by the United States FDA-approved diuretic bumetanide is a potential therapeutic strategy in preclinical/clinical studies of multiple neurological conditions. However, bumetanide has poor brain penetration and causes unwanted diuresis by inhibiting NKCC2 in the kidney. To overcome these issues, a growing number of studies have reported more brain-penetrating and/or selective bumetanide prodrugs, analogs, and new molecular entities. Here, we review the evidence for NKCC1 pharmacological inhibition as an effective strategy to manage neurological disorders. We also discuss the advantages and limitations of bumetanide repurposing and the benefits and risks of new NKCC1 inhibitors as therapeutic agents for brain disorders.
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Affiliation(s)
- Annalisa Savardi
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy; Dulbecco Telethon Institute, 00185 Rome, Italy; Molecular Modeling and Drug Discovery Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Marco Borgogno
- Molecular Modeling and Drug Discovery Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Marco De Vivo
- Molecular Modeling and Drug Discovery Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy.
| | - Laura Cancedda
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy; Dulbecco Telethon Institute, 00185 Rome, Italy.
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46
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Ma JJ, Zhang TY, Diao XT, Yao L, Li YX, Suo ZW, Yang X, Hu XD, Liu YN. BDNF modulated KCC2 ubiquitylation in spinal cord dorsal horn of mice. Eur J Pharmacol 2021; 906:174205. [PMID: 34048740 DOI: 10.1016/j.ejphar.2021.174205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 05/21/2021] [Accepted: 05/21/2021] [Indexed: 10/21/2022]
Abstract
The K+-Cl- co-transporter 2 (KCC2) is a neuron-specific Cl- extruder in the dorsal horn of spinal cord. The low intracellular Cl- concentration established by KCC2 is critical for GABAergic and glycinergic systems to generate synaptic inhibition. Peripheral nerve lesions have been shown to cause KCC2 dysfunction in adult spinal cord through brain-derived neurotrophic factor (BDNF) signaling, which switches the hyperpolarizing inhibitory transmission to be depolarizing and excitatory. However, the mechanisms by which BDNF impairs KCC2 function remain to be elucidated. Here we found that BDNF treatment enhanced KCC2 ubiquitination in the dorsal horn of adult mice, a post-translational modification that leads to KCC2 degradation. Our data showed that spinal BDNF application promoted KCC2 interaction with Casitas B-lineage lymphoma b (Cbl-b), one of the E3 ubiquitin ligases that are involved in the spinal processing of nociceptive information. Knockdown of Cbl-b expression decreased KCC2 ubiquitination level and attenuated the pain hypersensitivity induced by BDNF. Spared nerve injury significantly increased KCC2 ubiquitination, which could be reversed by inhibition of TrkB receptor. Our data implicated that KCC2 was one of the important pain-related substrates of Cbl-b and that ubiquitin modification contributed to BDNF-induced KCC2 hypofunction in the spinal cord.
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Affiliation(s)
- Juan-Juan Ma
- Department of Molecular Pharmacology, School of Pharmacy, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Tian-Yu Zhang
- Department of Molecular Pharmacology, School of Pharmacy, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Xin-Tong Diao
- Department of Molecular Pharmacology, School of Pharmacy, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Lin Yao
- Department of Molecular Pharmacology, School of Pharmacy, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Yin-Xia Li
- Department of Molecular Pharmacology, School of Pharmacy, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Zhan-Wei Suo
- Department of Molecular Pharmacology, School of Pharmacy, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Xian Yang
- Department of Molecular Pharmacology, School of Pharmacy, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Xiao-Dong Hu
- Department of Molecular Pharmacology, School of Pharmacy, Lanzhou University, Lanzhou, Gansu, 730000, PR China.
| | - Yan-Ni Liu
- Department of Molecular Pharmacology, School of Pharmacy, Lanzhou University, Lanzhou, Gansu, 730000, PR China.
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Gregus AM, Levine IS, Eddinger KA, Yaksh TL, Buczynski MW. Sex differences in neuroimmune and glial mechanisms of pain. Pain 2021; 162:2186-2200. [PMID: 34256379 PMCID: PMC8277970 DOI: 10.1097/j.pain.0000000000002215] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/03/2020] [Indexed: 02/07/2023]
Abstract
ABSTRACT Pain is the primary motivation for seeking medical care. Although pain may subside as inflammation resolves or an injury heals, it is increasingly evident that persistency of the pain state can occur with significant regularity. Chronic pain requires aggressive management to minimize its physiological consequences and diminish its impact on quality of life. Although opioids commonly are prescribed for intractable pain, concerns regarding reduced efficacy, as well as risks of tolerance and dependence, misuse, diversion, and overdose mortality rates limit their utility. Advances in development of nonopioid interventions hinge on our appreciation of underlying mechanisms of pain hypersensitivity. For instance, the contributory role of immunity and the associated presence of autoimmune syndromes has become of particular interest. Males and females exhibit fundamental differences in innate and adaptive immune responses, some of which are present throughout life, whereas others manifest with reproductive maturation. In general, the incidence of chronic pain conditions, particularly those with likely autoimmune covariates, is significantly higher in women. Accordingly, evidence is now accruing in support of neuroimmune interactions driving sex differences in the development and maintenance of pain hypersensitivity and chronicity. This review highlights known sexual dimorphisms of neuroimmune signaling in pain states modeled in rodents, which may yield potential high-value sex-specific targets to inform future analgesic drug discovery efforts.
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Affiliation(s)
- Ann M Gregus
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg, VA, United States
| | - Ian S Levine
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg, VA, United States
| | | | - Tony L Yaksh
- Departments of Anesthesiology and
- Pharmacology, University of California San Diego, La Jolla, CA, United States
| | - Matthew W Buczynski
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg, VA, United States
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48
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Inhibition of Glycine Re-Uptake: A Potential Approach for Treating Pain by Augmenting Glycine-Mediated Spinal Neurotransmission and Blunting Central Nociceptive Signaling. Biomolecules 2021; 11:biom11060864. [PMID: 34200954 PMCID: PMC8230656 DOI: 10.3390/biom11060864] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 12/23/2022] Open
Abstract
Among the myriad of cellular and molecular processes identified as contributing to pathological pain, disinhibition of spinal cord nociceptive signaling to higher cortical centers plays a critical role. Importantly, evidence suggests that impaired glycinergic neurotransmission develops in the dorsal horn of the spinal cord in inflammatory and neuropathic pain models and is a key maladaptive mechanism causing mechanical hyperalgesia and allodynia. Thus, it has been hypothesized that pharmacological agents capable of augmenting glycinergic tone within the dorsal horn may be able to blunt or block aberrant nociceptor signaling to the brain and serve as a novel class of analgesics for various pathological pain states. Indeed, drugs that enhance dysfunctional glycinergic transmission, and in particular inhibitors of the glycine transporters (GlyT1 and GlyT2), are generating widespread interest as a potential class of novel analgesics. The GlyTs are Na+/Cl−-dependent transporters of the solute carrier 6 (SLC6) family and it has been proposed that the inhibition of them presents a possible mechanism by which to increase spinal extracellular glycine concentrations and enhance GlyR-mediated inhibitory neurotransmission in the dorsal horn. Various inhibitors of both GlyT1 and GlyT2 have demonstrated broad analgesic efficacy in several preclinical models of acute and chronic pain, providing promise for the approach to deliver a first-in-class non-opioid analgesic with a mechanism of action differentiated from current standard of care. This review will highlight the therapeutic potential of GlyT inhibitors as a novel class of analgesics, present recent advances reported for the field, and discuss the key challenges associated with the development of a GlyT inhibitor into a safe and effective agent to treat pain.
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49
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Bouali-Benazzouz R, Landry M, Benazzouz A, Fossat P. Neuropathic pain modeling: Focus on synaptic and ion channel mechanisms. Prog Neurobiol 2021; 201:102030. [PMID: 33711402 DOI: 10.1016/j.pneurobio.2021.102030] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 02/22/2021] [Indexed: 12/28/2022]
Abstract
Animal models of pain consist of modeling a pain-like state and measuring the consequent behavior. The first animal models of neuropathic pain (NP) were developed in rodents with a total lesion of the sciatic nerve. Later, other models targeting central or peripheral branches of nerves were developed to identify novel mechanisms that contribute to persistent pain conditions in NP. Objective assessment of pain in these different animal models represents a significant challenge for pre-clinical research. Multiple behavioral approaches are used to investigate and to validate pain phenotypes including withdrawal reflex to evoked stimuli, vocalizations, spontaneous pain, but also emotional and affective behaviors. Furthermore, animal models were very useful in investigating the mechanisms of NP. This review will focus on a detailed description of rodent models of NP and provide an overview of the assessment of the sensory and emotional components of pain. A detailed inventory will be made to examine spinal mechanisms involved in NP-induced hyperexcitability and underlying the current pharmacological approaches used in clinics with the possibility to present new avenues for future treatment. The success of pre-clinical studies in this area of research depends on the choice of the relevant model and the appropriate test based on the objectives of the study.
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Affiliation(s)
- Rabia Bouali-Benazzouz
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.
| | - Marc Landry
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Abdelhamid Benazzouz
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Pascal Fossat
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
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50
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Kankowski S, Grothe C, Haastert-Talini K. Neuropathic pain: Spotlighting anatomy, experimental models, mechanisms, and therapeutic aspects. Eur J Neurosci 2021; 54:4475-4496. [PMID: 33942412 DOI: 10.1111/ejn.15266] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 04/19/2021] [Accepted: 04/28/2021] [Indexed: 12/30/2022]
Abstract
The International Association for the Study of Pain defines neuropathic pain as "pain arising as a direct consequence of a lesion or disease affecting the somatosensory system". The associated changes can be observed in the peripheral as well as the central nervous system. The available literature discusses a wide variety of causes as predisposing for the development and amplification of neuropathic pain. Further, key interactions within sensory pathways have been discovered, but no common molecular mechanism leading to neuropathic pain has been identified until now. In the first part of this review, the pain mediating lateral spinothalamic tract is described. Different in vivo models are presented that allow studying trauma-, chemotherapy-, virus-, and diabetes-induced neuropathic pain in rodents. We furthermore discuss approaches to assess neuropathic pain in these models. Second, the current knowledge about cellular and molecular mechanisms suggested to underlie the development of neuropathic pain is presented and discussed. A summary of established therapies that are already applied in the clinic and novel, promising approaches closes the paper. In conclusion, the established animal models are able to emulate the diversity of neuropathic pain observed in the clinics. However, the assessment of neuropathic pain in the presented in vivo models should be improved. The determination of common molecular markers with suitable in vitro models would simplify the assessment of neuropathic pain in vivo. This would furthermore provide insights into common molecular mechanisms of the disease and establish a basis to search for satisfying therapeutic approaches.
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Affiliation(s)
- Svenja Kankowski
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School (MHH), Hannover, Germany
| | - Claudia Grothe
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School (MHH), Hannover, Germany.,Center for Systems Neuroscience (ZNS) Hannover, Hannover, Germany
| | - Kirsten Haastert-Talini
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School (MHH), Hannover, Germany.,Center for Systems Neuroscience (ZNS) Hannover, Hannover, Germany
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