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Hawker P, Zhang L, Liu L. Mas-related G protein-coupled receptors in gastrointestinal dysfunction and inflammatory bowel disease: A review. Br J Pharmacol 2024; 181:2197-2211. [PMID: 36787888 DOI: 10.1111/bph.16059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/25/2022] [Accepted: 02/04/2023] [Indexed: 02/16/2023] Open
Abstract
Inflammatory bowel disease (IBD) is a chronic debilitating condition, hallmarked by persistent inflammation of the gastrointestinal tract. Despite recent advances in clinical treatments, the aetiology of IBD is unknown, and a large proportion of patients are refractory to pharmacotherapy. Understanding IBD immunopathogenesis is crucial to discern the cause of IBD and optimise treatments. Mas-related G protein-coupled receptors (Mrgprs) are a family of approximately 50 G protein-coupled receptors that were first identified over 20 years ago. Originally known for their expression in skin nociceptors and their role in transmitting the sensation of itch in the periphery, new reports have described the presence of Mrgprs in the gastrointestinal tract. In this review, we consider the impact of these findings and assess the evidence that suggests that Mrgprs may be involved in the disrupted homeostatic processes that contribute to gastrointestinal disorders and IBD. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
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Affiliation(s)
- Patrick Hawker
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Li Zhang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Lu Liu
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
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2
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Barakat A, Munro G, Heegaard AM. Finding new analgesics: Computational pharmacology faces drug discovery challenges. Biochem Pharmacol 2024; 222:116091. [PMID: 38412924 DOI: 10.1016/j.bcp.2024.116091] [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: 10/02/2023] [Revised: 01/10/2024] [Accepted: 02/23/2024] [Indexed: 02/29/2024]
Abstract
Despite the worldwide prevalence and huge burden of pain, pain is an undertreated phenomenon. Currently used analgesics have several limitations regarding their efficacy and safety. The discovery of analgesics possessing a novel mechanism of action has faced multiple challenges, including a limited understanding of biological processes underpinning pain and analgesia and poor animal-to-human translation. Computational pharmacology is currently employed to face these challenges. In this review, we discuss the theory, methods, and applications of computational pharmacology in pain research. Computational pharmacology encompasses a wide variety of theoretical concepts and practical methodological approaches, with the overall aim of gaining biological insight through data acquisition and analysis. Data are acquired from patients or animal models with pain or analgesic treatment, at different levels of biological organization (molecular, cellular, physiological, and behavioral). Distinct methodological algorithms can then be used to analyze and integrate data. This helps to facilitate the identification of biological molecules and processes associated with pain phenotype, build quantitative models of pain signaling, and extract translatable features between humans and animals. However, computational pharmacology has several limitations, and its predictions can provide false positive and negative findings. Therefore, computational predictions are required to be validated experimentally before drawing solid conclusions. In this review, we discuss several case study examples of combining and integrating computational tools with experimental pain research tools to meet drug discovery challenges.
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Affiliation(s)
- Ahmed Barakat
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Assiut University, Assiut, Egypt.
| | | | - Anne-Marie Heegaard
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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3
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Karimi SA, Zahra FT, Martin LJ. IUPHAR review: Navigating the role of preclinical models in pain research. Pharmacol Res 2024; 200:107073. [PMID: 38232910 DOI: 10.1016/j.phrs.2024.107073] [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: 12/01/2023] [Revised: 01/09/2024] [Accepted: 01/11/2024] [Indexed: 01/19/2024]
Abstract
Chronic pain is a complex and challenging medical condition that affects millions of people worldwide. Understanding the underlying mechanisms of chronic pain is a key goal of preclinical pain research so that more effective treatment strategies can be developed. In this review, we explore nociception, pain, and the multifaceted factors that lead to chronic pain by focusing on preclinical models. We provide a detailed look into inflammatory and neuropathic pain models and discuss the most used animal models for studying the mechanisms behind these conditions. Additionally, we emphasize the vital role of these preclinical models in developing new pain-relief drugs, focusing on biologics and the therapeutic potential of NMDA and cannabinoid receptor antagonists. We also discuss the challenges of TRPV1 modulation for pain treatment, the clinical failures of neurokinin (NK)- 1 receptor antagonists, and the partial success story of Ziconotide to provide valuable lessons for preclinical pain models. Finally, we highlight the overall success and limitations of current treatments for chronic pain while providing critical insights into the development of more effective therapies to alleviate the burden of chronic pain.
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Affiliation(s)
- Seyed Asaad Karimi
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Fatama Tuz Zahra
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Loren J Martin
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada; Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.
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Morris AJ, Parker RS, Nazzal MK, Natoli RM, Fehrenbacher JC, Kacena MA, White FA. Cracking the Code: The Role of Peripheral Nervous System Signaling in Fracture Repair. Curr Osteoporos Rep 2024; 22:193-204. [PMID: 38236511 PMCID: PMC10912155 DOI: 10.1007/s11914-023-00846-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/19/2023] [Indexed: 01/19/2024]
Abstract
PURPOSE OF REVIEW The traditionally understated role of neural regulation in fracture healing is gaining prominence, as recent findings underscore the peripheral nervous system's critical contribution to bone repair. Indeed, it is becoming more evident that the nervous system modulates every stage of fracture healing, from the onset of inflammation to repair and eventual remodeling. RECENT FINDINGS Essential to this process are neurotrophins and neuropeptides, such as substance P, calcitonin gene-related peptide, and neuropeptide Y. These molecules fulfill key roles in promoting osteogenesis, influencing inflammation, and mediating pain. The sympathetic nervous system also plays an important role in the healing process: while local sympathectomies may improve fracture healing, systemic sympathetic denervation impairs fracture healing. Furthermore, chronic activation of the sympathetic nervous system, often triggered by stress, is a potential impediment to effective fracture healing, marking an important area for further investigation. The potential to manipulate aspects of the nervous system offers promising therapeutic possibilities for improving outcomes in fracture healing. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.
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Affiliation(s)
- Ashlyn J Morris
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Reginald S Parker
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Murad K Nazzal
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Roman M Natoli
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jill C Fehrenbacher
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
- Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA.
- Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA.
| | - Fletcher A White
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA.
- Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
- Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA.
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN, USA.
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5
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Becker J, Effraim PR, Dib-Hajj S, Rittner HL. Lessons learned in translating pain knowledge into practice. Pain Rep 2023; 8:e1100. [PMID: 37928204 PMCID: PMC10624476 DOI: 10.1097/pr9.0000000000001100] [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: 11/16/2022] [Accepted: 05/05/2023] [Indexed: 11/07/2023] Open
Abstract
Introduction During the past 2 decades, basic research deciphering the underlying mechanisms of nociception and chronic pain was thought to finally step beyond opioids and nonsteroidals and provide patients with new analgesics. But apart from calcitonin gene-related peptide antagonists, nothing arrived in hands of clinicians. Objectives To present existing evidence of 3 representative target molecules in the development of novel pain treatment that, so far, did not result in approved drugs. Methods This Clinical Update aligns with the 2022 IASP Global Year Translating Pain Knowledge into Practice and selectively reviews best available evidence and practice. Results We highlight 3 targets: a ion channel, a neuronal growth factor, and a neuropeptide to explore why these drug targets have been dropped in clinical phase II-III trials. Antibodies to nerve growth factor had very good effects in musculoskeletal pain but resulted into more patients requiring joint replacements. Blockers of NaV1.7 were often not effective enough-at least if patients were not stratified. Blockers of neurokinin receptor were similarly not successful enough. In general, failure was most often to the result of a lack of effect and to a lesser extend because of unexpected severe side effects. However, all studies and trials lead to an enormous move in the scientific community to better preclinical models and testing as well as revised methods to molecularly phenotype and stratify patients. Conclusion All stakeholders in the process can help in the future: better preclinical studies, phenotyping and stratifying patients, and participation in clinical trials to move the discovery of analgesics forward.
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Affiliation(s)
- Juliane Becker
- Department of Anesthesiology, Intensive Care, Emergency and Pain Medicine, Center for Interdisciplinary Pain Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Philip R. Effraim
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
- Department of Neurology, Center for Neuroscience & Regeneration Research, Yale School of Medicine, New Haven, CT, USA
| | - Sulayman Dib-Hajj
- Department of Neurology, Center for Neuroscience & Regeneration Research, Yale School of Medicine, New Haven, CT, USA
- Rehabilitation Research Center, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Heike L. Rittner
- Department of Anesthesiology, Intensive Care, Emergency and Pain Medicine, Center for Interdisciplinary Pain Medicine, University Hospital Würzburg, Würzburg, Germany
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MacDonald DI, Jayabalan M, Seaman J, Nickolls A, Chesler A. Pain persists in mice lacking both Substance P and CGRPα signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.15.567208. [PMID: 38076807 PMCID: PMC10705526 DOI: 10.1101/2023.11.15.567208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
The neuropeptides Substance P and CGRPα have long been thought important for pain sensation. Both peptides and their receptors are expressed at high levels in pain-responsive neurons from the periphery to the brain making them attractive therapeutic targets. However, drugs targeting these pathways individually did not relieve pain in clinical trials. Since Substance P and CGRPα are extensively co-expressed we hypothesized that their simultaneous inhibition would be required for effective analgesia. We therefore generated Tac1 and Calca double knockout (DKO) mice and assessed their behavior using a wide range of pain-relevant assays. As expected, Substance P and CGRPα peptides were undetectable throughout the nervous system of DKO mice. To our surprise, these animals displayed largely intact responses to mechanical, thermal, chemical, and visceral pain stimuli, as well as itch. Moreover, chronic inflammatory pain and neurogenic inflammation were unaffected by loss of the two peptides. Finally, neuropathic pain evoked by nerve injury or chemotherapy treatment was also preserved in peptide-deficient mice. Thus, our results demonstrate that even in combination, Substance P and CGRPα are not required for the transmission of acute and chronic pain.
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Affiliation(s)
- Donald Iain MacDonald
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, United States
| | - Monessha Jayabalan
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, United States
| | - Jonathan Seaman
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, United States
| | - Alec Nickolls
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, United States
| | - Alexander Chesler
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, United States
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
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Yu H, Usoskin D, Nagi SS, Hu Y, Kupari J, Bouchatta O, Cranfill SL, Gautam M, Su Y, Lu Y, Wymer J, Glanz M, Albrecht P, Song H, Ming GL, Prouty S, Seykora J, Wu H, Ma M, Rice FL, Olausson H, Ernfors P, Luo W. Single-Soma Deep RNA sequencing of Human DRG Neurons Reveals Novel Molecular and Cellular Mechanisms Underlying Somatosensation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.533207. [PMID: 36993480 PMCID: PMC10055202 DOI: 10.1101/2023.03.17.533207] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The versatility of somatosensation arises from heterogeneous dorsal root ganglion (DRG) neurons. However, soma transcriptomes of individual human DRG (hDRG) neurons-critical in-formation to decipher their functions-are lacking due to technical difficulties. Here, we developed a novel approach to isolate individual hDRG neuron somas for deep RNA sequencing (RNA-seq). On average, >9,000 unique genes per neuron were detected, and 16 neuronal types were identified. Cross-species analyses revealed remarkable divergence among pain-sensing neurons and the existence of human-specific nociceptor types. Our deep RNA-seq dataset was especially powerful for providing insight into the molecular mechanisms underlying human somatosensation and identifying high potential novel drug targets. Our dataset also guided the selection of molecular markers to visualize different types of human afferents and the discovery of novel functional properties using single-cell in vivo electrophysiological recordings. In summary, by employing a novel soma sequencing method, we generated an unprecedented hDRG neuron atlas, providing new insights into human somatosensation, establishing a critical foundation for translational work, and clarifying human species-species properties.
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8
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Ramirez-Garcia PD, Veldhuis NA, Bunnett NW, Davis TP. Targeting endosomal receptors, a new direction for polymers in nanomedicine. J Mater Chem B 2023; 11:5390-5399. [PMID: 37219363 PMCID: PMC10641892 DOI: 10.1039/d3tb00156c] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this perspective, we outline a new opportunity for exploiting nanoparticle delivery of antagonists to target G-protein coupled receptors localized in intracellular compartments. We discuss the specific example of antagonizing endosomal receptors involved in pain to develop long-lasting analgesics but also outline the broader application potential of this delivery approach. We discuss the materials used to target endosomal receptors and indicate the design requirements for future successful applications.
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Affiliation(s)
- Paulina D Ramirez-Garcia
- Dentistry Translational Research Center, New York University College of Dentistry, New York, 10010, USA.
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY 10010, USA
| | - Nicholas A Veldhuis
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Nigel W Bunnett
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY 10010, USA
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone School of Medicine, New York, NY 10010, USA
| | - Thomas P Davis
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia.
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9
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Xie S, Xie M, Shen Y, Cheng D. Gabapentin for chronic refractory cough: A system review and meta-analysis. Heliyon 2023; 9:e15579. [PMID: 37131438 PMCID: PMC10149207 DOI: 10.1016/j.heliyon.2023.e15579] [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: 11/25/2022] [Revised: 04/11/2023] [Accepted: 04/14/2023] [Indexed: 05/04/2023] Open
Abstract
Objective To evaluate the efficacy and safety of gabapentin in the treatment of chronic refractory cough by Meta-Analysis. Methods Literatures were retrieved from PubMed, Embase (OvidIP), Cochrane Library, CNKI, VIP, Wanfang Database and China Biomedical Management System and eligible prospective studies were screened. Data were extracted and analyzed by using RevMan 5.4.1 software. Results Six articles (2 RCTs and 4 prospective studies) with 536 participants were finally included. Meta-analysis showed that gabapentin was better than placebo in cough-specific quality of life (LCQ score, MD = 4.02, 95%CI [3.26,4,78], Z = 10.34, P < 0.00001), cough severity (VAS score, MD = -29.36, 95% CI (-39.46, -19.26), Z = 5.7, P < 0.00001), cough frequency (MD = -29.87, 95% CI [- 43.84, -15.91], Z = 4.19, P < 0.0001) and therapeutic efficacy (RR = 1.37,95%CI [1.13,1.65], Z = 3.27, P = 0.001), and equal in safety (RR = 1.32,95%CI [0.47,3.7], Z = 0.53, P = 0.59). Gabapentin was similar to other neuromodulators in therapeutic efficacy (RR = 1.07,95%CI [0.87,1.32], Z = 0.64, P = 0.52), but its safety was better. Conclusion Gabapentin is effective in the treatment of chronic refractory cough in both subjective and objective evaluations, and its safety is better than other neuromodulators.
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Affiliation(s)
- Sheng Xie
- Department of Pulmonary and Critical Care Medicine, Chengdu First People's Hospital, Sichuan, China
| | - Meiling Xie
- Department of Traditional Chinese Medicine, Sichuan Electric Power Hospital, Sichuan, China
| | - Yongchun Shen
- Department of Pulmonary and Critical Care Medicine, West China Hospital, Sichuan University, Sichuan, China
| | - Deyun Cheng
- Department of Pulmonary and Critical Care Medicine, West China Hospital, Sichuan University, Sichuan, China
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Baamonde A, Menéndez L. Experiences and reflections about behavioral pain assays in laboratory animals. J Neurosci Methods 2023; 386:109783. [PMID: 36610617 DOI: 10.1016/j.jneumeth.2023.109783] [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: 07/29/2022] [Revised: 11/30/2022] [Accepted: 01/02/2023] [Indexed: 01/05/2023]
Abstract
Pharmacological assays based on the measurement of nociceptive responses in laboratory animals are a fundamental tool to assess analgesic strategies. During our experience with this type of experiments, we have been repeatedly challenged by different concerns related to their interpretation or relevance. Although these subjects are frequently discussed in our lab, they do not usually find a place in research articles with original data, in which the focus on results seems mandatory. In the present manuscript we try to discuss as central issues some of these aspects that often cross transversally our research. We have gathered them in five topics inspired by the results obtained in our laboratory. The two initial sections are devoted to the influence of the behavioral method used to assess nociception on the results achieved, as well as to the possibility that data may be more easily accepted when obtained with standard methods than with alternative ones. The third topic is related to the difficulties encountered when working with a molecule that may evoke dual effects, acting as pronociceptive or antinociceptive depending on the dose. The fourth point deals with the situation in which a particular hyperalgesic reaction is related to several molecules but the single inhibition of only one of them can completely prevent it. Finally, the last issue is addressed to comment the impact in the progress of pain research of experiments performed in animal models of pathological settings.
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Affiliation(s)
- Ana Baamonde
- Laboratorio de Farmacología, Facultad de Medicina, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA) Oviedo, Asturias, Spain
| | - Luis Menéndez
- Laboratorio de Farmacología, Facultad de Medicina, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA) Oviedo, Asturias, Spain.
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László S, Bátai IZ, Berkó S, Csányi E, Dombi Á, Pozsgai G, Bölcskei K, Botz L, Wagner Ö, Pintér E. Development of Capsaicin-Containing Analgesic Silicone-Based Transdermal Patches. Pharmaceuticals (Basel) 2022; 15:ph15101279. [PMID: 36297391 PMCID: PMC9611826 DOI: 10.3390/ph15101279] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/29/2022] [Accepted: 10/13/2022] [Indexed: 12/03/2022] Open
Abstract
Transdermal therapeutic systems (TTSs) enable convenient dosing in drug therapy. Modified silicone-polymer-based patches are well-controlled and cost-effective matrix diffusion systems. In the present study, we investigated the substance release properties, skin penetration, and analgesic effect of this type of TTS loaded with low-dose capsaicin. Release properties were measured in Franz diffusion cell and continuous flow-through cell approaches. Capsaicin was detected with HPLC-UV and UV spectrophotometry. Raman spectroscopy was conducted on human skin samples exposed to the TTS. A surgical incision or carrageenan injection was performed on one hind paw of male Wistar rats. TTSs were applied to the epilated dorsal skin. Patches were kept on the animals for 6 h. The thermal hyperalgesia and mechanical pain threshold of the hind paws were detected. Patches exhibited controlled, zero-order kinetic capsaicin release. According to the Raman mapping, capsaicin penetrated into the epidermis and dermis of human skin, where the target receptors are expressed. The thermal pain threshold drop of the operated rat paws was reversed by capsaicin treatment compared to that of animals treated with control patches. It was concluded that our modified silicone-polymer-based capsaicin-containing TTS is suitable for the relief of traumatic and inflammatory pain.
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Affiliation(s)
- Szabolcs László
- Department of Inorganic and Analytical Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti u. 12, H-7624 Pécs, Hungary
| | - István Z. Bátai
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti u. 12, H-7624 Pécs, Hungary
- Molecular Pharmacology Research Group, Szentágothai Research Centre, University of Pécs, Ifjúság ú. 20, H-7624 Pécs, Hungary
| | - Szilvia Berkó
- Institute of Pharmaceutical Technology and Regulatory Affairs, Faculty of Pharmacy, University of Szeged, Eötvös str. 6, H-6720 Szeged, Hungary
| | - Erzsébet Csányi
- Institute of Pharmaceutical Technology and Regulatory Affairs, Faculty of Pharmacy, University of Szeged, Eötvös str. 6, H-6720 Szeged, Hungary
| | - Ágnes Dombi
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti u. 12, H-7624 Pécs, Hungary
- Molecular Pharmacology Research Group, Szentágothai Research Centre, University of Pécs, Ifjúság ú. 20, H-7624 Pécs, Hungary
| | - Gábor Pozsgai
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti u. 12, H-7624 Pécs, Hungary
- Molecular Pharmacology Research Group, Szentágothai Research Centre, University of Pécs, Ifjúság ú. 20, H-7624 Pécs, Hungary
- Correspondence: ; Tel.: +36-72-536-217
| | - Kata Bölcskei
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti u. 12, H-7624 Pécs, Hungary
- Molecular Pharmacology Research Group, Szentágothai Research Centre, University of Pécs, Ifjúság ú. 20, H-7624 Pécs, Hungary
| | - Lajos Botz
- Department of Pharmaceutics and Central Clinical Pharmacy, Faculty of Pharmacy, University of Pécs, Honvéd u. 3., H-7624 Pécs, Hungary
| | - Ödön Wagner
- Department of Inorganic and Analytical Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary
| | - Erika Pintér
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti u. 12, H-7624 Pécs, Hungary
- Molecular Pharmacology Research Group, Szentágothai Research Centre, University of Pécs, Ifjúság ú. 20, H-7624 Pécs, Hungary
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12
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Jiang W, Tan XY, Li JM, Yu P, Dong M. DNA Methylation: A Target in Neuropathic Pain. Front Med (Lausanne) 2022; 9:879902. [PMID: 35872752 PMCID: PMC9301322 DOI: 10.3389/fmed.2022.879902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 06/06/2022] [Indexed: 11/13/2022] Open
Abstract
Neuropathic pain (NP), caused by an injury or a disease affecting the somatosensory nervous system of the central and peripheral nervous systems, has become a global health concern. Recent studies have demonstrated that epigenetic mechanisms are among those that underlie NP; thus, elucidating the molecular mechanism of DNA methylation is crucial to discovering new therapeutic methods for NP. In this review, we first briefly discuss DNA methylation, demethylation, and the associated key enzymes, such as methylases and demethylases. We then discuss the relationship between NP and DNA methylation, focusing on DNA methyltransferases including methyl-CpG-binding domain (MBD) family proteins and ten-eleven translocation (TET) enzymes. Based on experimental results of neuralgia in animal models, the mechanism of DNA methylation-related neuralgia is summarized, and useful targets for early drug intervention in NP are discussed.
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Affiliation(s)
- Wei Jiang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Xuan-Yu Tan
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, China
| | - Jia-Ming Li
- Department of Emergency, The First Hospital of Jilin University, Changchun, China
| | - Peng Yu
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, China
- *Correspondence: Peng Yu
| | - Ming Dong
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
- Ming Dong
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Abdus-Saboor I, Luo W. Measuring Mouse Somatosensory Reflexive Behaviors with High-speed Videography, Statistical Modeling, and Machine Learning. NEUROMETHODS 2022; 178:441-456. [PMID: 35783537 PMCID: PMC9249079 DOI: 10.1007/978-1-0716-2039-7_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Objectively measuring and interpreting an animal's sensory experience remains a challenging task. This is particularly true when using preclinical rodent models to study pain mechanisms and screen for potential new pain treatment reagents. How to determine their pain states in a precise and unbiased manner is a hurdle that the field will need to overcome. Here, we describe our efforts to measure mouse somatosensory reflexive behaviors with greatly improved precision by high-speed video imaging. We describe how coupling sub-second ethograms of reflexive behaviors with a statistical reduction method and supervised machine learning can be used to create a more objective quantitative mouse "pain scale." Our goal is to provide the readers with a protocol of how to integrate some of the new tools described here with currently used mechanical somatosensory assays, while discussing the advantages and limitations of this new approach.
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Affiliation(s)
- Ishmail Abdus-Saboor
- Department of Biology, University of Pennsylvania, 3740 Hamilton Walk, Philadelphia, PA, 19104, USA
| | - Wenqin Luo
- Department of Neuroscience, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA, 19104, USA
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14
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Kim MS, Kim BY, Saghetlians A, Zhang X, Okida T, Kim SY. Anti-nociceptive effects of dual neuropeptide antagonist therapy in mouse model of neuropathic and inflammatory pain. Korean J Pain 2022; 35:173-182. [PMID: 35354680 PMCID: PMC8977203 DOI: 10.3344/kjp.2022.35.2.173] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/10/2022] [Accepted: 03/10/2022] [Indexed: 11/05/2022] Open
Abstract
Background Neurokinin-1 (NK1) and calcitonin gene-related peptide (CGRP) play a vital role in pain pathogenesis, and these proteins' antagonists have attracted attention as promising pharmaceutical candidates. The authors investigated the antinociceptive effect of co-administration of the CGRP antagonist and an NK1 antagonist on pain models compared to conventional single regimens. Methods C57Bl/6J mice underwent sciatic nerve ligation for the neuropathic pain model and were injected with 4% formalin into the hind paw for the inflammatory pain model. Each model was divided into four groups: vehicle, NK1 antagonist, CGRP antagonist, and combination treatment groups. The NK1 antagonist aprepitant (BIBN4096, 1 mg/kg) or the CGRP antagonist olcegepant (MK-0869, 10 mg/kg) was injected intraperitoneally. Mechanical allodynia, thermal hypersensitivity, and anxiety-related behaviors were assessed using the von Frey, hot plate, and elevated plus-maze tests. The flinching and licking responses were also evaluated after formalin injection. Results Co-administration of aprepitant and olcegepant more significantly alleviated pain behaviors than administration of single agents or vehicle, increasing the mechanical threshold and improving the response latency. Anxiety-related behaviors were also markedly improved after dual treatment compared with either naive mice or the neuropathic pain model in the dual treatment group. Flinching frequency and licking response after formalin injection decreased significantly in the dual treatment group. Isobolographic analysis showed a meaningful additive effect between the two compounds. Conclusions A combination pharmacological therapy comprised of multiple neuropeptide antagonists could be a more effective therapeutic strategy for alleviating neuropathic or inflammatory pain.
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Affiliation(s)
- Min Su Kim
- Department of Rehabilitation Medicine, Wonkwang University College of Medicine, Iksan, Korea
| | - Bo Yeon Kim
- Department of Rehabilitation Medicine, Wonkwang University College of Medicine, Iksan, Korea.,Salk Institute for Biological Studies, La Jolla, CA, USA
| | | | - Xiang Zhang
- Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Takuya Okida
- Salk Institute for Biological Studies, La Jolla, CA, USA
| | - So Yeon Kim
- Department of Rehabilitation Medicine, Wonkwang University College of Medicine, Iksan, Korea.,Salk Institute for Biological Studies, La Jolla, CA, USA
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15
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A systematic review of porcine models in translational pain research. Lab Anim (NY) 2021; 50:313-326. [PMID: 34650279 DOI: 10.1038/s41684-021-00862-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 08/27/2021] [Indexed: 11/09/2022]
Abstract
Translating basic pain research from rodents to humans has proven to be a challenging task. Efforts have been made to develop preclinical large animal models of pain, such as the pig. However, no consistent overview and comparison of pig models of pain are currently available. Therefore, in this review, our primary aim was to identify the available pig models in pain research and compare these models in terms of intensity and duration. First, we systematically searched Proquest, Scopus and Web of Science and compared the duration for which the pigs were significantly sensitized as well as the intensity of mechanical sensitization. We searched models within the specific field of pain and adjacent fields in which pain induction or assessment is relevant, such as pig production. Second, we compared assessment methodologies in surrogate pain models in humans and pigs to identify areas of overlap and possible improvement. Based on the literature search, 23 types of porcine pain models were identified; 13 of which could be compared quantitatively. The induced sensitization lasted from hours to months and intensities ranged from insignificant to the maximum attainable. We also found a near to complete overlap of assessment methodologies between human and pig models within the area of peripheral neurophysiology, which allows for direct comparison of results obtained in the two species. In spite of this overlap, further development of pain assessment methodologies is still needed. We suggest that central nervous system electrophysiology, such as electroencephalography, electrocorticography or intracortical recordings, may pave the way for future objective pain assessment.
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16
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Lasagni Vitar RM, Barbariga M, Fonteyne P, Bignami F, Rama P, Ferrari G. Modulating Ocular Surface Pain Through Neurokinin-1 Receptor Blockade. Invest Ophthalmol Vis Sci 2021; 62:26. [PMID: 33729475 PMCID: PMC7980039 DOI: 10.1167/iovs.62.3.26] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose The purpose of this study was to test the role of substance P (SP) and its receptor neurokinin 1 (NK1R) on ocular surface pain. Methods Eight-week-old C57BL6/N (wild type [WT]) and B6.Cg-Tac1tm1Bbm/J (TAC1-KO) male mice were used. 5 M NaCl was topically applied on the cornea, followed by topical fosaprepitant 2, 10, and 50 mg/mL; 4 mg/mL oxybuprocaine chloride, or 0.1% diclofenac. Th eye wiping test was used to quantify ocular surface pain. SP content was quantified in the tear fluid and trigeminal ganglia (TG), and TAC1 mRNA was assessed in the cornea. Corneas were immunostained for β3-tubulin and NK1R, or CD45, to quantify leukocyte infiltration. Results TAC1-KO mice displayed a significant reduction of ocular pain (P < 0.001). Similarly, a single dose of 10 or 50 mg/mL fosaprepitant applied topically to WT mice reduced ocular pain as compared to vehicle (P < 0.001). Fosaprepitant 2 mg/mL, instead, induced corneal analgesia only when it was administered for 10 days, 6 times/day (P < 0.05). Diclofenac or oxybuprocaine reduced corneal nociception when compared to vehicle or fosaprepitant (P < 0.05). Fosaprepitant or oxybuprocaine groups showed lower SP content in tear secretions and TG (P < 0.05), and reduction in TAC1 mRNA (P < 0.05), and leukocyte infiltration (P < 0.05) in the cornea. Colocalization of NK1R and β3-tubulin was detected in mouse corneas. Conclusions Topical administration of the NK1R antagonist fosaprepitant effectively reduces ocular surface nociception by decreasing SP release in the tear fluid and TG, and corneal leukocyte infiltration. Fosaprepitant repurposing shows promise for the treatment of ocular pain.
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Affiliation(s)
- Romina Mayra Lasagni Vitar
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marco Barbariga
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Philippe Fonteyne
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Fabio Bignami
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Paolo Rama
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giulio Ferrari
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
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17
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Draxler P, Moen A, Galek K, Boghos A, Ramazanova D, Sandkühler J. Spontaneous, Voluntary, and Affective Behaviours in Rat Models of Pathological Pain. FRONTIERS IN PAIN RESEARCH 2021; 2:672711. [PMID: 35295455 PMCID: PMC8915731 DOI: 10.3389/fpain.2021.672711] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/25/2021] [Indexed: 12/30/2022] Open
Abstract
In pain patients affective and motivational reactions as well as impairment of daily life activities dominate the clinical picture. In contrast, many rodent pain models have been established on the basis of mechanical hypersensitivity testing. Up to today most rodent studies on pain still rely on reflexive withdrawal responses only. This discrepancy has likely contributed to the low predictive power of preclinical pain models for novel therapies. Here, we used a behavioural test array for rats to behaviourally evaluate five aetiologically distinct pain models consisting of inflammatory-, postsurgical-, cephalic-, neuropathic- and chemotherapy-induced pain. We assessed paralleling clinical expressions and comorbidities of chronic pain with an array of behavioural tests to assess anxiety, social interaction, distress, depression, and voluntary/spontaneous behaviours. Pharmacological treatment of the distinct pain conditions was performed with pathology-specific and clinically efficacious analgesics as gabapentin, sumatriptan, naproxen, and codeine. We found that rats differed in their manifestation of symptoms depending on the pain model and that pathology-specific analgesics also reduced the associated behavioural parameters. Based on all behavioural test performed, we screened for tests that can discriminate experimental groups on the basis of reflexive as well as non-sensory, affective parameters. Together, we propose a set of non-evoked behaviours with a comparable predictive power to mechanical threshold testing for each pain model.
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Affiliation(s)
- Peter Draxler
- Division of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Aurora Moen
- Division of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Karolina Galek
- Division of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Ani Boghos
- Division of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Dariga Ramazanova
- Center for Medical Statistics, Informatics and Intelligent Systems (CeMSIIS) Section for Medical Statistics, Medical University of Vienna, Vienna, Austria
| | - Jürgen Sandkühler
- Division of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
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18
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Hasriadi, Wasana PWD, Vajragupta O, Rojsitthisak P, Towiwat P. Automated home-cage for the evaluation of innate non-reflexive pain behaviors in a mouse model of inflammatory pain. Sci Rep 2021; 11:12240. [PMID: 34112846 PMCID: PMC8192791 DOI: 10.1038/s41598-021-91444-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 05/24/2021] [Indexed: 02/05/2023] Open
Abstract
The failure to develop analgesic drugs is attributed not only to the complex and diverse pathophysiology of pain in humans but also to the poor experimental design and poor preclinical assessment of pain. Although considerable efforts have been devoted to overcoming the relevant problems, many features of the behavioral pain assessment remain to be characterized. For example, a decreased locomotor activity as a common presentation of pain-like behavior has yet to be described. Studies on mice experimentally induced with carrageenan have provided opportunities to explore pain-related behaviors in automated home-cage monitoring. Through this approach, the locomotor activities of mice with carrageenan-induced inflammatory pain can be precisely and objectively captured. Here, we found that the mobile behaviors of mice reduced, and their immobility increased, indicating that carrageenan induction in mice caused a significant decrease in locomotor activity. These non-reflexive pain behaviors were strongly correlated with the reflexive pain behaviors measured via von Frey and plantar tests. Furthermore, the pharmacological intervention using indomethacin improved the locomotor activity of mice with carrageenan-induced pain. Thus, the analysis of the locomotor activity in automated home-cage monitoring is useful for studying the behavioral analgesia and the pharmacological screening of analgesic drugs. The combined evaluation of reflexive and non-reflexive pain behaviors enhances the translational utility of preclinical pain research in rodents.
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Affiliation(s)
- Hasriadi
- Pharmaceutical Sciences and Technology Program, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Peththa Wadu Dasuni Wasana
- Pharmaceutical Sciences and Technology Program, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Opa Vajragupta
- Research Affairs, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Pornchai Rojsitthisak
- Department of Food and Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
- Natural Products for Ageing and Chronic Diseases Research Unit, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Pasarapa Towiwat
- Natural Products for Ageing and Chronic Diseases Research Unit, Chulalongkorn University, Bangkok, 10330, Thailand.
- Department of Pharmacology and Physiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 10330, Thailand.
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19
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Karna SR, Chambers P, Singh P, Lopez-Villalobos N, Kongara K. Evaluation of analgesic interaction between morphine, maropitant and dexmedetomidine in dogs undergoing ovariohysterectomy. N Z Vet J 2021; 70:10-21. [PMID: 33950785 DOI: 10.1080/00480169.2021.1927231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
ABSTRACTAims: To compare the analgesic effect of morphine combined with maropitant and/or dexmedetomidine to morphine alone but at a higher dose, and to evaluate the pharmacokinetics of the drug combinations, in dogs undergoing ovariohysterectomy (OHE).Methods: Forty client-owned dogs were randomised into four treatment groups (n = 10 per group) each to receive a different analgesic protocol. After premedication with I/M acepromazine, anaesthesia was induced with propofol to effect and maintained with isoflurane in 100% oxygen delivered via a circle system. The heart rate, respiratory rate, blood pressure, haemoglobin oxygen saturation, end-tidal partial pressure of carbon dioxide, electrocardiogram and rectal temperature were monitored during anaesthesia. The test drugs (Mor: 0.6 mg/kg morphine; Maro + Mor: 0.3 mg/kg morphine and 1 mg/kg maropitant; Dex + Mor: 0.3 mg/kg morphine and 10 μg/kg dexmedetomidine; Dex + Maro + Mor: 0.2 mg/kg morphine, 7 μg/kg dexmedetomidine and 0.7 mg/kg maropitant) were administered I/M after induction of anaesthesia and 30 minutes before the expected start time of ovariohysterectomy, which was carried out by veterinary students under veterinary supervision. The short form of the Glasgow composite measure pain scale (CMPS-SF) and visual analogue scale (VAS) were used for pain assessment at 15 and 30 minutes and 1, 2, 3, 6, 9 and 24 hours after extubation. Dogs with CMPS-SF pain score ≥ 6 received rescue analgesia with S/C buprenorphine (0.02 mg/kg). Blood samples were collected before, 15, 30, 60 and 120 minutes after injection of the test drugs and concentration of the test drugs in plasma was determined by liquid chromatography-mass spectrometry.Results: Dogs that received Dex + Mor had significantly lower CMPS-SF (estimate of difference = -1.53 (SE 0.58); p = 0.010) and VAS (estimate of difference = -0.67 (SE 0.25); p = 0.007) scores compared to the dogs that received morphine alone. There was no evidence of a difference in the number of dogs requiring rescue between groups. All dogs that received dexmedetomidine showed cardiac arrhythmia and second-degree heart block. Mean (SD) maximum concentrations (Cmax,) of morphine in plasma were 6.8 (4.56), 9.56 (8.29), 9.30 (3.35) and 18.99 (9.41) ng/mL for the groups Dex + Mor, Dex + Maro + Mor, Maro + Mor and Mor respectively. The Cmax of morphine was significantly lower in the Dex + Mor (p = 0.004), Dex + Maro + Mor (p = 0.034) and Maro + Mor (p = 0.018) groups compared to the Mor group.Conclusions For dogs undergoing ovariohysterectomy, lower doses of morphine (0.2 and 0.3 mg/kg) combined with dexmedetomidine or maropitant may provide analgesia equivalent to or better than morphine when given alone at a higher dose (0.6 mg/kg).Abbreviations: AUC: Area under curve; Cmax: Maximum concentration in plasma; CMPS-SF: Glasgow composite measure pain scale - short form; NK1: Neurokinin-1; OHE: Ovariohysterectomy; Tmax: Time to Cmax; T1/2: Half-life of terminal elimination phase; VAS: Visual analogue scale.
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Affiliation(s)
- S R Karna
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - P Chambers
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - P Singh
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - N Lopez-Villalobos
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - K Kongara
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
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20
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Cho C, Deol HK, Martin LJ. Bridging the Translational Divide in Pain Research: Biological, Psychological and Social Considerations. Front Pharmacol 2021; 12:603186. [PMID: 33935700 PMCID: PMC8082136 DOI: 10.3389/fphar.2021.603186] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 02/22/2021] [Indexed: 12/29/2022] Open
Abstract
A gap exists between translating basic science research into effective pain therapies in humans. While preclinical pain research has primarily used animal models to understand biological processes, a lesser focus has been toward using animal models to fully consider other components of the pain experience, such as psychological and social influences. Herein, we provide an overview of translational studies within pain research by breaking them down into purely biological, psychological and social influences using a framework derived from the biopsychosocial model. We draw from a wide landscape of studies to illustrate that the pain experience is highly intricate, and every attempt must be made to address its multiple components and interactors to aid in fully understanding its complexity. We highlight our work where we have developed animal models to assess the cognitive and social effects on pain modulation while conducting parallel experiments in people that provide proof-of-importance for human pain modulation. In some instances, human pain research has sparked the development of novel animal models, with these animal models used to better understand the complexity of phenomena considered to be uniquely human such as placebo responses and empathy.
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Affiliation(s)
- Chulmin Cho
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Harashdeep K Deol
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Loren J Martin
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
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21
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Fibromyalgia: Pathogenesis, Mechanisms, Diagnosis and Treatment Options Update. Int J Mol Sci 2021; 22:ijms22083891. [PMID: 33918736 PMCID: PMC8068842 DOI: 10.3390/ijms22083891] [Citation(s) in RCA: 151] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 12/13/2022] Open
Abstract
Fibromyalgia is a syndrome characterized by chronic and widespread musculoskeletal pain, often accompanied by other symptoms, such as fatigue, intestinal disorders and alterations in sleep and mood. It is estimated that two to eight percent of the world population is affected by fibromyalgia. From a medical point of view, this pathology still presents inexplicable aspects. It is known that fibromyalgia is caused by a central sensitization phenomenon characterized by the dysfunction of neuro-circuits, which involves the perception, transmission and processing of afferent nociceptive stimuli, with the prevalent manifestation of pain at the level of the locomotor system. In recent years, the pathogenesis of fibromyalgia has also been linked to other factors, such as inflammatory, immune, endocrine, genetic and psychosocial factors. A rheumatologist typically makes a diagnosis of fibromyalgia when the patient describes a history of pain spreading in all quadrants of the body for at least three months and when pain is caused by digital pressure in at least 11 out of 18 allogenic points, called tender points. Fibromyalgia does not involve organic damage, and several diagnostic approaches have been developed in recent years, including the analysis of genetic, epigenetic and serological biomarkers. Symptoms often begin after physical or emotional trauma, but in many cases, there appears to be no obvious trigger. Women are more prone to developing the disease than men. Unfortunately, the conventional medical therapies that target this pathology produce limited benefits. They remain largely pharmacological in nature and tend to treat the symptomatic aspects of various disorders reported by the patient. The statistics, however, highlight the fact that 90% of people with fibromyalgia also turn to complementary medicine to manage their symptoms.
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22
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Chen W, McRoberts JA, Ennes HS, Marvizon JC. cAMP signaling through protein kinase A and Epac2 induces substance P release in the rat spinal cord. Neuropharmacology 2021; 189:108533. [PMID: 33744339 DOI: 10.1016/j.neuropharm.2021.108533] [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: 08/12/2020] [Revised: 03/01/2021] [Accepted: 03/11/2021] [Indexed: 11/18/2022]
Abstract
Using neurokinin 1 receptor (NK1R) internalization to measure of substance P release in rat spinal cord slices, we found that it was induced by the adenylyl cyclase (AC) activator forskolin, by the protein kinase A (PKA) activators 6-Bnz-cAMP and 8-Br-cAMP, and by the activator of exchange protein activated by cAMP (Epac) 8-pCPT-2-O-Me-cAMP (CPTOMe-cAMP). Conversely, AC and PKA inhibitors decreased substance P release induced by electrical stimulation of the dorsal root. Therefore, the cAMP signaling pathway mediates substance P release in the dorsal horn. The effects of forskolin and 6-Bnz-cAMP were not additive with NMDA-induced substance P release and were decreased by the NMDA receptor blocker MK-801. In cultured dorsal horn neurons, forskolin increased NMDA-induced Ca2+ entry and the phosphorylation of the NR1 and NR2B subunits of the NMDA receptor. Therefore, cAMP-induced substance P release is mediated by the activating phosphorylation by PKA of NMDA receptors. Voltage-gated Ca2+ channels, but not by TRPV1 or TRPA1, also contributed to cAMP-induced substance P release. Activation of PKA was required for the effects of forskolin and the three cAMP analogs. Epac2 contributed to the effects of forskolin and CPTOMe-cAMP, signaling through a Raf - mitogen-activated protein kinase pathway to activate Ca2+ channels. Epac1 inhibitors induced NK1R internalization independently of substance P release. In rats with latent sensitization to pain, the effect of 6-Bnz-cAMP was unchanged, whereas the effect of forskolin was decreased due to the loss of the stimulatory effect of Epac2. Hence, substance P release induced by cAMP decreases during pain hypersensitivity.
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Affiliation(s)
- Wenling Chen
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA; Veteran Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA
| | - James A McRoberts
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Helena S Ennes
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Juan Carlos Marvizon
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA; Veteran Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA.
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23
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Mouraux A, Bannister K, Becker S, Finn DP, Pickering G, Pogatzki-Zahn E, Graven-Nielsen T. Challenges and opportunities in translational pain research - An opinion paper of the working group on translational pain research of the European pain federation (EFIC). Eur J Pain 2021; 25:731-756. [PMID: 33625769 PMCID: PMC9290702 DOI: 10.1002/ejp.1730] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
For decades, basic research on the underlying mechanisms of nociception has held promise to translate into efficacious treatments for patients with pain. Despite great improvement in the understanding of pain physiology and pathophysiology, translation to novel, effective treatments for acute and chronic pain has however been limited, and they remain an unmet medical need. In this opinion paper bringing together pain researchers from very different disciplines, the opportunities and challenges of translational pain research are discussed. The many factors that may prevent the successful translation of bench observations into useful and effective clinical applications are reviewed, including interspecies differences, limited validity of currently available preclinical disease models of pain, and limitations of currently used methods to assess nociception and pain in non-human and human models of pain. Many paths are explored to address these issues, including the backward translation of observations made in patients and human volunteers into new disease models that are more clinically relevant, improved generalization by taking into account age and sex differences, and the integration of psychobiology into translational pain research. Finally, it is argued that preclinical and clinical stages of developing new treatments for pain can be improved by better preclinical models of pathological pain conditions alongside revised methods to assess treatment-induced effects on nociception in human and non-human animals. Significance: For decades, basic research of the underlying mechanisms of nociception has held promise to translate into efficacious treatments for patients with pain. Despite great improvement in the understanding of pain physiology and pathophysiology, translation to novel, effective treatments for acute and chronic pain has however been limited, and they remain an unmet medical need.
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Affiliation(s)
- André Mouraux
- Institute of Neuroscience (IONS), UCLouvain, Brussels, Belgium
| | - Kirsty Bannister
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Susanne Becker
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - David P Finn
- Pharmacology and Therapeutics, Centre for Pain Research, School of Medicine, National University of Ireland Galway, Galway, Ireland
| | - Gisèle Pickering
- Department of Clinical Pharmacology, Inserm CIC 1405, University Hospital, CHU Clermont-Ferrand, France.,Fundamental and Clinical Pharmacology of Pain, University Clermont Auvergne, Clermont-Ferrand, France
| | - Esther Pogatzki-Zahn
- Department of Anesthesiology, Critical Care Medicine and Pain Therapy, University Hospital Muenster, Muenster, Germany
| | - Thomas Graven-Nielsen
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark
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24
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Shiers SI, Sankaranarayanan I, Jeevakumar V, Cervantes A, Reese JC, Price TJ. Convergence of peptidergic and non-peptidergic protein markers in the human dorsal root ganglion and spinal dorsal horn. J Comp Neurol 2021; 529:2771-2788. [PMID: 33550628 DOI: 10.1002/cne.25122] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/16/2022]
Abstract
Peripheral sensory neurons are characterized by their size, molecular profiles, and physiological responses to specific stimuli. In mouse, the peptidergic and non-peptidergic subsets of nociceptors are distinct and innervate different lamina of the spinal dorsal horn. The unique molecular signature and neuroanatomical organization of these neurons supports a labeled line theory for certain types of nociceptive stimuli. However, long-standing evidence supports the polymodal nature of nociceptors in many species. We have recently shown that the peptidergic marker, CGRP, and the non-peptidergic marker, P2X3R, show largely overlapping expression at the mRNA level in human dorsal root ganglion (DRG). Herein, our aim was to assess the protein distribution of nociceptor markers, including their central projections, in the human DRG and spinal cord. Using DRGs obtained from organ donors, we observed that CGRP and P2X3R were co-expressed by approximately 33% of human DRG neurons and TrpV1 was expressed in ~60% of human DRG neurons. In the dorsal spinal cord, CGRP, P2X3R, TrpV1, and Nav1.7 proteins stained the entirety of lamina 1-2, with only P2XR3 showing a gradient of expression. This was confirmed by measuring the size of the substantia gelatinosa using Hematoxylin and Eosin staining of adjacent sections. Our findings are consistent with the known polymodal nature of most primate nociceptors and indicate that the central projection patterns of nociceptors are different between mice and humans. Elucidating how human nociceptors connect to subsets of dorsal horn neurons will be important for understanding the physiological consequences of these species differences.
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Affiliation(s)
- Stephanie I Shiers
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Ishwarya Sankaranarayanan
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Vivek Jeevakumar
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | | | | | - Theodore J Price
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA
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25
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Fisher AS, Lanigan MT, Upton N, Lione LA. Preclinical Neuropathic Pain Assessment; the Importance of Translatability and Bidirectional Research. Front Pharmacol 2021; 11:614990. [PMID: 33628181 PMCID: PMC7897667 DOI: 10.3389/fphar.2020.614990] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/10/2020] [Indexed: 02/04/2023] Open
Abstract
For patients suffering with chronic neuropathic pain the need for suitable novel therapies is imperative. Over recent years a contributing factor for the lack of development of new analgesics for neuropathic pain has been the mismatch of primary neuropathic pain assessment endpoints in preclinical vs. clinical trials. Despite continuous forward translation failures across diverse mechanisms, reflexive quantitative sensory testing remains the primary assessment endpoint for neuropathic pain and analgesia in animals. Restricting preclinical evaluation of pain and analgesia to exclusively reflexive outcomes is over simplified and can be argued not clinically relevant due to the continued lack of forward translation and failures in the clinic. The key to developing new analgesic treatments for neuropathic pain therefore lies in the development of clinically relevant endpoints that can translate preclinical animal results to human clinical trials. In this review we discuss this mismatch of primary neuropathic pain assessment endpoints, together with clinical and preclinical evidence that supports how bidirectional research is helping to validate new clinically relevant neuropathic pain assessment endpoints. Ethological behavioral endpoints such as burrowing and facial grimacing and objective measures such as electroencephalography provide improved translatability potential together with currently used quantitative sensory testing endpoints. By tailoring objective and subjective measures of neuropathic pain the translatability of new medicines for patients suffering with neuropathic pain will hopefully be improved.
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Affiliation(s)
- Amy S Fisher
- Transpharmation Ltd., The London Bioscience Innovation Centre, London, United Kingdom
| | - Michael T Lanigan
- Transpharmation Ltd., The London Bioscience Innovation Centre, London, United Kingdom.,School of Life and Medical Sciences, University of Hertfordshire, Hatfield, United Kingdom
| | - Neil Upton
- Transpharmation Ltd., The London Bioscience Innovation Centre, London, United Kingdom
| | - Lisa A Lione
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, United Kingdom
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26
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Kokhan VS, Mariasina S, Pikalov VA, Abaimov DA, Somasundaram SG, Kirkland CE, Aliev G. Neurokinin-1 receptor antagonist reverses functional CNS alteration caused by combined γ-rays and carbon nuclei irradiation. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2021; 21:278-289. [PMID: 33480350 DOI: 10.2174/1871527320666210122092330] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 10/06/2020] [Accepted: 10/19/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Ionizing radiation (IR) is one of the major limiting factors for human deep-space missions. Preventing IR-induced cognitive alterations in astronauts is a critical success factor. It has been shown that cognitive alterations in rodents can be inferred by alterations of a psycho-emotional balance, primarily an anxiogenic effect of IR. In our recent work we hypothesized that the neurokinin-1 (NK1) receptor may be instrumental for such alterations. OBJECTIVE The NK1 receptor antagonist rolapitant and the classic anxiolytic diazepam (as a comparison drug) were selected to test this hypothesis on Wistar rats. METHOD Pharmacological substances were administered through intragastric probes. We used a battery of tests for a comprehensive ethological analysis. A high-performance liquid chromatography was applied to quantify monoamines content. An analysis of mRNA expression was performed by real-time PCR. Protein content was studied by Western blotting technique. RESULTS Our salient finding includes no substantial changes in anxiety, locomotor activity and cognitive abilities of treated rats under irradiation. No differences were found in the content of monoamines. We discovered a synchronous effect on mRNA expression and protein content of 5-HT2a and 5-HT4 receptors in the prefrontal cortex, as well as decreased content of serotonin transporter and increased content of tryptophan hydroxylase in the hypothalamus of irradiated rats. Rolapitant affected the protein amount of a number of serotonin receptors in the amygdala of irradiated rats. CONCLUSION Rolapitant may be the first atypical radioprotector, providing symptomatic treatment of CNS functional disorders in astronauts caused by IR.
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Affiliation(s)
- Viktor S Kokhan
- V.P. Serbsky Federal Medical Research Centre for Psychiatry and Narcology, Moscow. Russian Federation
| | - Sofia Mariasina
- M.V. Lomonosov Moscow State University, Moscow. Russian Federation
| | - Vladimir A Pikalov
- Institute for High Energy Physics named by A.A. Logunov of NRC "Kurchatov Institute", Protvino. Russian Federation
| | | | - Siva G Somasundaram
- Department of Biological Sciences, Salem University, Salem, WV, 26426. United States
| | - Cecil E Kirkland
- Department of Biological Sciences, Salem University, Salem, WV, 26426. United States
| | - Gjumrakch Aliev
- I. M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 8/2 Trubetskaya Str., Moscow, 119991. Russian Federation
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27
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Green DP. The role of Mrgprs in pain. Neurosci Lett 2021; 744:135544. [PMID: 33421487 DOI: 10.1016/j.neulet.2020.135544] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/16/2020] [Accepted: 11/26/2020] [Indexed: 11/17/2022]
Abstract
Owing to their functional diversity, the Mas-related G-protein-coupled receptor (Mrgpr) family has a role in both itch and pain modulation. While primarily linked to pruritis, Mrgprs were originally characterized in small-diameter nociceptive neurons of dorsal root ganglia (DRG) and trigeminal ganglia. This review will focus on the role Mrgpr's have in pain physiology, discussing recent discoveries as well as how Mrgpr's may provide a new target for the treatment of pathological pain.
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Affiliation(s)
- Dustin P Green
- Department of Neuroscience, Cell Biology, & Anatomy, University of Texas Medical Branch, Galveston, TX, USA
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28
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Eagles DA, Chow CY, King GF. Fifteen years of Na
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1.7 channels as an analgesic target: Why has excellent in vitro pharmacology not translated into in vivo analgesic efficacy? Br J Pharmacol 2020; 179:3592-3611. [DOI: 10.1111/bph.15327] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/14/2020] [Accepted: 10/23/2020] [Indexed: 12/16/2022] Open
Affiliation(s)
- David A. Eagles
- Institute for Molecular Bioscience The University of Queensland St Lucia QLD Australia
| | - Chun Yuen Chow
- Institute for Molecular Bioscience The University of Queensland St Lucia QLD Australia
| | - Glenn F. King
- Institute for Molecular Bioscience The University of Queensland St Lucia QLD Australia
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29
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Multifunctional Opioid-Derived Hybrids in Neuropathic Pain: Preclinical Evidence, Ideas and Challenges. Molecules 2020; 25:molecules25235520. [PMID: 33255641 PMCID: PMC7728063 DOI: 10.3390/molecules25235520] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 12/21/2022] Open
Abstract
When the first- and second-line therapeutics used to treat neuropathic pain (NP) fail to induce efficient analgesia—which is estimated to relate to more than half of the patients—opioid drugs are prescribed. Still, the pathological changes following the nerve tissue injury, i.a. pronociceptive neuropeptide systems activation, oppose the analgesic effects of opiates, enforcing the use of relatively high therapeutic doses in order to obtain satisfying pain relief. In parallel, the repeated use of opioid agonists is associated with burdensome adverse effects due to compensatory mechanisms that arise thereafter. Rational design of hybrid drugs, in which opioid ligands are combined with other pharmacophores that block the antiopioid action of pronociceptive systems, delivers the opportunity to ameliorate the NP-oriented opioid treatment via addressing neuropathological mechanisms shared both by NP and repeated exposition to opioids. Therewith, the new dually acting drugs, tailored for the specificity of NP, can gain in efficacy under nerve injury conditions and have an improved safety profile as compared to selective opioid agonists. The current review presents the latest ideas on opioid-comprising hybrid drugs designed to treat painful neuropathy, with focus on their biological action, as well as limitations and challenges related to this therapeutic approach.
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30
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Sheahan TD, Warwick CA, Fanien LG, Ross SE. The Neurokinin-1 Receptor is Expressed with Gastrin-Releasing Peptide Receptor in Spinal Interneurons and Modulates Itch. J Neurosci 2020; 40:8816-8830. [PMID: 33051347 PMCID: PMC7659450 DOI: 10.1523/jneurosci.1832-20.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/25/2020] [Accepted: 09/21/2020] [Indexed: 12/22/2022] Open
Abstract
The neurokinin-1 receptor (NK1R; encoded by Tacr1) is expressed in spinal dorsal horn neurons and has been suggested to mediate itch in rodents. However, previous studies relied heavily on neurotoxic ablation of NK1R spinal neurons, which limited further dissection of their function in spinal itch circuitry. To address this limitation, we leveraged a newly developed Tacr1CreER mouse line to characterize the role of NK1R spinal neurons in itch. We show that pharmacological activation of spinal NK1R and chemogenetic activation of Tacr1CreER spinal neurons increases itch behavior in male and female mice, whereas pharmacological inhibition of spinal NK1R suppresses itch behavior. We use fluorescence in situ hybridization (FISH) to characterize the endogenous expression of Tacr1 throughout the superficial and deeper dorsal horn (DDH), as well as the lateral spinal nucleus (LSN), of mouse and human spinal cord. Retrograde labeling studies in mice from the parabrachial nucleus (PBN) show that less than 20% of superficial Tacr1CreER dorsal horn neurons are spinal projection neurons, and thus the majority of Tacr1CreER are local interneurons. We then use a combination of in situ hybridization and ex vivo two-photon Ca2+ imaging of the mouse spinal cord to establish that NK1R and the gastrin-releasing peptide receptor (GRPR) are coexpressed within a subpopulation of excitatory superficial dorsal horn (SDH) neurons. These findings are the first to suggest a role for NK1R interneurons in itch and extend our understanding of the complexities of spinal itch circuitry.SIGNIFICANCE STATEMENT The spinal cord is a critical hub for processing somatosensory input, yet which spinal neurons process itch input and how itch signals are encoded within the spinal cord is not fully understood. We demonstrate neurokinin-1 receptor (NK1R) spinal neurons mediate itch behavior in mice and that the majority of NK1R spinal neurons are local interneurons. These NK1R neurons comprise a subset of gastrin-releasing peptide receptor (GRPR) interneurons and are thus positioned at the center of spinal itch transmission. We show NK1R mRNA expression in human spinal cord, underscoring the translational relevance of our findings in mice. This work is the first to suggest a role for NK1R interneurons in itch and extends our understanding of the complexities of spinal itch circuitry.
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Affiliation(s)
- Tayler D Sheahan
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh 15213, Pennsylvania
| | - Charles A Warwick
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh 15213, Pennsylvania
| | - Louis G Fanien
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh 15213, Pennsylvania
| | - Sarah E Ross
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh 15213, Pennsylvania
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31
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Abboud C, Duveau A, Bouali-Benazzouz R, Massé K, Mattar J, Brochoire L, Fossat P, Boué-Grabot E, Hleihel W, Landry M. Animal models of pain: Diversity and benefits. J Neurosci Methods 2020; 348:108997. [PMID: 33188801 DOI: 10.1016/j.jneumeth.2020.108997] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 11/03/2020] [Accepted: 11/08/2020] [Indexed: 12/15/2022]
Abstract
Chronic pain is a maladaptive neurological disease that remains a major health problem. A deepening of our knowledge on mechanisms that cause pain is a prerequisite to developing novel treatments. A large variety of animal models of pain has been developed that recapitulate the diverse symptoms of different pain pathologies. These models reproduce different pain phenotypes and remain necessary to examine the multidimensional aspects of pain and understand the cellular and molecular basis underlying pain conditions. In this review, we propose an overview of animal models, from simple organisms to rodents and non-human primates and the specific traits of pain pathologies they model. We present the main behavioral tests for assessing pain and investing the underpinning mechanisms of chronic pathological pain. The validity of animal models is analysed based on their ability to mimic human clinical diseases and to predict treatment outcomes. Refine characterization of pathological phenotypes also requires to consider pain globally using specific procedures dedicated to study emotional comorbidities of pain. We discuss the limitations of pain models when research findings fail to be translated from animal models to human clinics. But we also point to some recent successes in analgesic drug development that highlight strategies for improving the predictive validity of animal models of pain. Finally, we emphasize the importance of using assortments of preclinical pain models to identify pain subtype mechanisms, and to foster the development of better analgesics.
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Affiliation(s)
- Cynthia Abboud
- Univ. Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, F-33000 Bordeaux, France; Univ. Bordeaux, CNRS, Institute for Neurodegenerative Diseases, IMN, UMR 5293, F-33000 Bordeaux, France; Faculty of Arts and Sciences, Holy Spirit University of Kaslik (USEK), Lebanon
| | - Alexia Duveau
- Univ. Bordeaux, CNRS, Institute for Neurodegenerative Diseases, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Rabia Bouali-Benazzouz
- Univ. Bordeaux, CNRS, Institute for Neurodegenerative Diseases, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Karine Massé
- Univ. Bordeaux, CNRS, Institute for Neurodegenerative Diseases, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Joseph Mattar
- School of Medicine and Medical Sciences, Holy Spirit University of Kaslik (USEK), Lebanon
| | - Louison Brochoire
- Univ. Bordeaux, CNRS, Institute for Neurodegenerative Diseases, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Pascal Fossat
- Univ. Bordeaux, CNRS, Institute for Neurodegenerative Diseases, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Eric Boué-Grabot
- Univ. Bordeaux, CNRS, Institute for Neurodegenerative Diseases, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Walid Hleihel
- School of Medicine and Medical Sciences, Holy Spirit University of Kaslik (USEK), Lebanon; Faculty of Arts and Sciences, Holy Spirit University of Kaslik (USEK), Lebanon
| | - Marc Landry
- Univ. Bordeaux, CNRS, Institute for Neurodegenerative Diseases, IMN, UMR 5293, F-33000 Bordeaux, France.
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32
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Fight fire with fire: Neurobiology of capsaicin-induced analgesia for chronic pain. Pharmacol Ther 2020; 220:107743. [PMID: 33181192 DOI: 10.1016/j.pharmthera.2020.107743] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/04/2020] [Indexed: 12/12/2022]
Abstract
Capsaicin, the pungent ingredient in chili peppers, produces intense burning pain in humans. Capsaicin selectively activates the transient receptor potential vanilloid 1 (TRPV1), which is enriched in nociceptive primary afferents, and underpins the mechanism for capsaicin-induced burning pain. Paradoxically, capsaicin has long been used as an analgesic. The development of topical patches and injectable formulations containing capsaicin has led to application in clinical settings to treat chronic pain conditions, such as neuropathic pain and the potential to treat osteoarthritis. More detailed determination of the neurobiological mechanisms of capsaicin-induced analgesia should provide the logical rationale for capsaicin therapy and help to overcome the treatment's limitations, which include individual differences in treatment outcome and procedural discomfort. Low concentrations of capsaicin induce short-term defunctionalization of nociceptor terminals. This phenomenon is reversible within hours and, hence, likely does not account for the clinical benefit. By contrast, high concentrations of capsaicin lead to long-term defunctionalization mediated by the ablation of TRPV1-expressing afferent terminals, resulting in long-lasting analgesia persisting for several months. Recent studies have shown that capsaicin-induced Ca2+/calpain-mediated ablation of axonal terminals is necessary to produce long-lasting analgesia in a mouse model of neuropathic pain. In combination with calpain, axonal mitochondrial dysfunction and microtubule disorganization may also contribute to the longer-term effects of capsaicin. The analgesic effects subside over time in association with the regeneration of the ablated afferent terminals. Further determination of the neurobiological mechanisms of capsaicin-induced analgesia should lead to more efficacious non-opioidergic analgesic options with fewer adverse side effects.
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33
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Choi S, Hachisuka J, Brett MA, Magee AR, Omori Y, Iqbal NUA, Zhang D, DeLisle MM, Wolfson RL, Bai L, Santiago C, Gong S, Goulding M, Heintz N, Koerber HR, Ross SE, Ginty DD. Parallel ascending spinal pathways for affective touch and pain. Nature 2020; 587:258-263. [PMID: 33116307 PMCID: PMC7666110 DOI: 10.1038/s41586-020-2860-1] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 07/28/2020] [Indexed: 12/13/2022]
Abstract
The anterolateral pathway consists of ascending spinal tracts that convey pain, temperature and touch information from the spinal cord to the brain1-4. Projection neurons of the anterolateral pathway are attractive therapeutic targets for pain treatment because nociceptive signals emanating from the periphery are channelled through these spinal projection neurons en route to the brain. However, the organizational logic of the anterolateral pathway remains poorly understood. Here we show that two populations of projection neurons that express the structurally related G-protein-coupled receptors (GPCRs) TACR1 and GPR83 form parallel ascending circuit modules that cooperate to convey thermal, tactile and noxious cutaneous signals from the spinal cord to the lateral parabrachial nucleus of the pons. Within this nucleus, axons of spinoparabrachial (SPB) neurons that express Tacr1 or Gpr83 innervate distinct sets of subnuclei, and strong optogenetic stimulation of the axon terminals induces distinct escape behaviours and autonomic responses. Moreover, SPB neurons that express Gpr83 are highly sensitive to cutaneous mechanical stimuli and receive strong synaptic inputs from both high- and low-threshold primary mechanosensory neurons. Notably, the valence associated with activation of SPB neurons that express Gpr83 can be either positive or negative, depending on stimulus intensity. These findings reveal anatomically, physiologically and functionally distinct subdivisions of the SPB tract that underlie affective aspects of touch and pain.
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Affiliation(s)
- Seungwon Choi
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Junichi Hachisuka
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA.,Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, PA, USA.,Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK
| | - Matthew A Brett
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Alexandra R Magee
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Yu Omori
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA.,Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, PA, USA.,Toray Industries, Inc., Pharmaceutical Research Laboratories, Kanagawa, Japan
| | - Noor-Ul-Aine Iqbal
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Dawei Zhang
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Michelle M DeLisle
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Rachel L Wolfson
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Ling Bai
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Celine Santiago
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Shiaoching Gong
- The Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Martyn Goulding
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Nathaniel Heintz
- The Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - H Richard Koerber
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA.,Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sarah E Ross
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA.,Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
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34
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Chen W, Marvizon JC. Neurokinin 1 receptor activation in the rat spinal cord maintains latent sensitization, a model of inflammatory and neuropathic chronic pain. Neuropharmacology 2020; 177:108253. [PMID: 32736088 PMCID: PMC10863619 DOI: 10.1016/j.neuropharm.2020.108253] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/16/2020] [Accepted: 07/23/2020] [Indexed: 12/21/2022]
Abstract
Latent sensitization is a model of chronic pain in which a persistent state of pain hypersensitivity is suppressed by opioid receptors, as evidenced by the ability of opioid antagonists to induce a period of mechanical allodynia. Our objective was to determine if substance P and its neurokinin 1 receptor (NK1R) mediate the maintenance of latent sensitization. Latent sensitization was induced by injecting rats in the hindpaw with complete Freund's adjuvant (CFA), or by tibial spared nerve injury (SNI). When responses to von Frey filaments returned to baseline (day 28), the rats were injected intrathecally with saline or the NK1R antagonist RP67580, followed 15 min later by intrathecal naltrexone. In both pain models, the saline-injected rats developed allodynia for 2 h after naltrexone, but not the RP67580-injected rats. Saline or RP67580 were injected daily for two more days. Five days later (day 35), naltrexone was injected intrathecally. Again, the saline-injected rats, but not the RP67580-injected rats, developed allodynia in response to naltrexone. To determine if there is sustained activation of NK1Rs during latent sensitization, NK1R internalization was measured in lamina I neurons in rats injected in the paw with saline or CFA, and then injected intrathecally with saline or naltrexone on day 28. The rats injected with CFA had a small amount of NK1R internalization that was significantly higher than in the saline-injected rats. Naltrexone increased NK1R internalization in the CFA-injected rats but nor in the saline-injected rats. Therefore, sustained activation of NK1Rs maintains pain hypersensitivity during latent sensitization.
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Affiliation(s)
- Wenling Chen
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA; Veteran Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA
| | - Juan Carlos Marvizon
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA; Veteran Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA.
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35
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Verrico CD, Wesson S, Konduri V, Hofferek CJ, Vazquez-Perez J, Blair E, Dunner K, Salimpour P, Decker WK, Halpert MM. A randomized, double-blind, placebo-controlled study of daily cannabidiol for the treatment of canine osteoarthritis pain. Pain 2020; 161:2191-2202. [PMID: 32345916 PMCID: PMC7584779 DOI: 10.1097/j.pain.0000000000001896] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/16/2020] [Indexed: 01/01/2023]
Abstract
ABSTRACT Over the last 2 decades, affirmative diagnoses of osteoarthritis (OA) in the United States have tripled due to increasing rates of obesity and an aging population. Hemp-derived cannabidiol (CBD) is the major nontetrahydrocannabinol component of cannabis and has been promoted as a potential treatment for a wide variety of disparate inflammatory conditions. Here, we evaluated CBD for its ability to modulate the production of proinflammatory cytokines in vitro and in murine models of induced inflammation and further validated the ability of a liposomal formulation to increase bioavailability in mice and in humans. Subsequently, the therapeutic potential of both naked and liposomally encapsulated CBD was explored in a 4-week, randomized placebo-controlled, double-blinded study in a spontaneous canine model of OA. In vitro and in mouse models, CBD significantly attenuated the production of proinflammatory cytokines IL-6 and TNF-α while elevating levels of anti-inflammatory IL-10. In the veterinary study, CBD significantly decreased pain and increased mobility in a dose-dependent fashion among animals with an affirmative diagnosis of OA. Liposomal CBD (20 mg/day) was as effective as the highest dose of nonliposomal CBD (50 mg/day) in improving clinical outcomes. Hematocrit, comprehensive metabolic profile, and clinical chemistry indicated no significant detrimental impact of CBD administration over the 4-week analysis period. This study supports the safety and therapeutic potential of hemp-derived CBD for relieving arthritic pain and suggests follow-up investigations in humans are warranted.
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Affiliation(s)
- Chris D. Verrico
- Department of Psychiatry, Baylor College of Medicine, Houston TX 77030
- Department of Pharmacology, Baylor College of Medicine, Houston TX 77030
| | | | - Vanaja Konduri
- Department of Pathology & Immunology, Baylor College of Medicine, Houston TX 77030
| | - Colby J. Hofferek
- Department of Pathology & Immunology, Baylor College of Medicine, Houston TX 77030
| | | | | | - Kenneth Dunner
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston TX 77030
| | | | - William K. Decker
- Department of Pathology & Immunology, Baylor College of Medicine, Houston TX 77030
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston TX 77030
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston TX 77030
| | - Matthew M. Halpert
- Department of Pathology & Immunology, Baylor College of Medicine, Houston TX 77030
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Abstract
A limited number of peripheral targets generate pain. Inflammatory mediators can sensitize these. The review addresses targets acting exclusively or predominantly on sensory neurons, mediators involved in inflammation targeting sensory neurons, and mediators involved in a more general inflammatory process, of which an analgesic effect secondary to an anti-inflammatory effect can be expected. Different approaches to address these systems are discussed, including scavenging proinflammatory mediators, applying anti-inflammatory mediators, and inhibiting proinflammatory or facilitating anti-inflammatory receptors. New approaches are contrasted to established ones; the current stage of progress is mentioned, in particular considering whether there is data from a molecular and cellular level, from animals, or from human trials, including an early stage after a market release. An overview of publication activity is presented, considering a IuPhar/BPS-curated list of targets with restriction to pain-related publications, which was also used to identify topics.
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Affiliation(s)
- Cosmin I Ciotu
- Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Michael J M Fischer
- Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria.
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37
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Female-Specific Effects of CGRP Suggest Limited Efficacy of New Migraine Treatments in Males. J Neurosci 2020; 39:9062-9064. [PMID: 31723033 DOI: 10.1523/jneurosci.1254-19.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/12/2019] [Accepted: 09/21/2019] [Indexed: 11/21/2022] Open
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38
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Feickert M, Burckhardt BB. A design of experiments concept for the minimization of nonspecific peptide adsorption in the mass spectrometric determination of substance P and related hemokinin‐1. J Sep Sci 2020; 43:818-828. [DOI: 10.1002/jssc.201901038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/14/2019] [Accepted: 11/17/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Martin Feickert
- Institute of Clinical Pharmacy and PharmacotherapyHeinrich Heine University Dusseldorf Germany
| | - Bjoern B Burckhardt
- Institute of Clinical Pharmacy and PharmacotherapyHeinrich Heine University Dusseldorf Germany
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39
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Sun S, Diggins NH, Gunderson ZJ, Fehrenbacher JC, White FA, Kacena MA. No pain, no gain? The effects of pain-promoting neuropeptides and neurotrophins on fracture healing. Bone 2020; 131:115109. [PMID: 31715336 PMCID: PMC6934100 DOI: 10.1016/j.bone.2019.115109] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/10/2019] [Accepted: 10/10/2019] [Indexed: 12/30/2022]
Abstract
Neuropeptides and neurotrophins are key regulators of peripheral nociceptive nerves and contribute to the induction, sensitization, and maintenance of pain. It is now known that these peptides also regulate non-neuronal tissues, including bone. Here, we review the effects of numerous neuropeptides and neurotrophins on fracture healing. The neuropeptides calcitonin-gene related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP), and pituitary adenylate cyclase-activating peptide (PACAP) have varying effects on osteoclastic and osteoblastic activity. Ultimately, CGRP and SP both accelerate fracture healing, while VIP and PACAP seem to negatively impact healing. Unlike the aforementioned neuropeptides, the neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) have more uniform effects. Both factors upregulate osteoblastic activity, osteoclastic activity, and, in vivo, stimulate osteogenesis to promote fracture healing. Future research will need to clarify the exact mechanism by which the neuropeptides and neurotrophins influence fracture healing. Specifically, understanding the optimal expression patterns for these proteins in the fracture healing process may lead to therapies that can maximize their bone-healing capabilities and minimize their pain-promoting effects. Finally, further examination of protein-sequestering antibodies and/or small molecule agonists and antagonists may lead to new therapies that can decrease the rate of delayed union/nonunion outcomes and fracture-associated pain.
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Affiliation(s)
- Seungyup Sun
- Department of Orthopaedic Surgery, Indiana University School of Medicine, IN, USA
| | - Nicklaus H Diggins
- Department of Orthopaedic Surgery, Indiana University School of Medicine, IN, USA
| | - Zachary J Gunderson
- Department of Orthopaedic Surgery, Indiana University School of Medicine, IN, USA
| | - Jill C Fehrenbacher
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, IN, USA
| | - Fletcher A White
- Department of Anesthesia, Indiana University School of Medicine, IN, USA; Richard L. Roudebush VA Medical Center, IN, USA
| | - Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Medicine, IN, USA; Richard L. Roudebush VA Medical Center, IN, USA.
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40
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Smith TM, Lee D, Bradley K, McMahon SB. Methodology for quantifying excitability of identified projection neurons in the dorsal horn of the spinal cord, specifically to study spinal cord stimulation paradigms. J Neurosci Methods 2020; 330:108479. [DOI: 10.1016/j.jneumeth.2019.108479] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 10/22/2019] [Indexed: 11/28/2022]
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41
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Manion J, Waller MA, Clark T, Massingham JN, Neely GG. Developing Modern Pain Therapies. Front Neurosci 2019; 13:1370. [PMID: 31920521 PMCID: PMC6933609 DOI: 10.3389/fnins.2019.01370] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 12/04/2019] [Indexed: 12/24/2022] Open
Abstract
Chronic pain afflicts as much as 50% of the population at any given time but our methods to address pain remain limited, ineffective and addictive. In order to develop new therapies an understanding of the mechanisms of painful sensitization is essential. We discuss here recent progress in the understanding of mechanisms underlying pain, and how these mechanisms are being targeted to produce modern, specific therapies for pain. Finally, we make recommendations for the next generation of targeted, effective, and safe pain therapies.
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Affiliation(s)
- John Manion
- The Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Matthew A. Waller
- The Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Teleri Clark
- The Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Joshua N. Massingham
- The Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - G. Gregory Neely
- The Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
- Genome Editing Initiative, The University of Sydney, Sydney, NSW, Australia
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42
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Wtorek K, Adamska-Bartłomiejczyk A, Piekielna-Ciesielska J, Ferrari F, Ruzza C, Kluczyk A, Piasecka-Zelga J, Calo’ G, Janecka A. Synthesis and Pharmacological Evaluation of Hybrids Targeting Opioid and Neurokinin Receptors. Molecules 2019; 24:molecules24244460. [PMID: 31817441 PMCID: PMC6943619 DOI: 10.3390/molecules24244460] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/28/2019] [Accepted: 12/02/2019] [Indexed: 11/16/2022] Open
Abstract
Morphine, which acts through opioid receptors, is one of the most efficient analgesics for the alleviation of severe pain. However, its usefulness is limited by serious side effects, including analgesic tolerance, constipation, and dependence liability. The growing awareness that multifunctional ligands which simultaneously activate two or more targets may produce a more desirable drug profile than selectively targeted compounds has created an opportunity for a new approach to developing more effective medications. Here, in order to better understand the role of the neurokinin system in opioid-induced antinociception, we report the synthesis, structure–activity relationship, and pharmacological characterization of a series of hybrids combining opioid pharmacophores with either substance P (SP) fragments or neurokinin receptor (NK1) antagonist fragments. On the bases of the in vitro biological activities of the hybrids, two analogs, opioid agonist/NK1 antagonist Tyr-[d-Lys-Phe-Phe-Asp]-Asn-d-Trp-Phe-d-Trp-Leu-Nle-NH2 (2) and opioid agonist/NK1 agonist Tyr-[d-Lys-Phe-Phe-Asp]-Gln-Phe-Phe-Gly-Leu-Met-NH2 (4), were selected for in vivo tests. In the writhing test, both hybrids showed significant an antinociceptive effect in mice, while neither of them triggered the development of tolerance, nor did they produce constipation. No statistically significant differences in in vivo activity profiles were observed between opioid/NK1 agonist and opioid/NK1 antagonist hybrids.
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Affiliation(s)
- Karol Wtorek
- Department of Biomolecular Chemistry, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland; (K.W.); (A.A.-B.); (J.P.-C.)
| | - Anna Adamska-Bartłomiejczyk
- Department of Biomolecular Chemistry, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland; (K.W.); (A.A.-B.); (J.P.-C.)
| | - Justyna Piekielna-Ciesielska
- Department of Biomolecular Chemistry, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland; (K.W.); (A.A.-B.); (J.P.-C.)
| | - Federica Ferrari
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, 44121 Ferrara, Italy; (F.F.); (C.R.); (G.C.)
| | - Chiara Ruzza
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, 44121 Ferrara, Italy; (F.F.); (C.R.); (G.C.)
| | - Alicja Kluczyk
- Faculty of Chemistry, University of Wroclaw, 50-383 Wroclaw, Poland;
| | - Joanna Piasecka-Zelga
- Institute of Occupational Medicine, Research Laboratory for Medicine and Veterinary Products in the GMP Head of Research Laboratory for Medicine and Veterinary Products, 91-348 Lodz, Poland;
| | - Girolamo Calo’
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, 44121 Ferrara, Italy; (F.F.); (C.R.); (G.C.)
| | - Anna Janecka
- Department of Biomolecular Chemistry, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland; (K.W.); (A.A.-B.); (J.P.-C.)
- Correspondence:
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43
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Ganchingco JRC, Fukuyama T, Yoder JA, Bäumer W. Calcium imaging of primary canine sensory neurons: Small-diameter neurons responsive to pruritogens and algogens. Brain Behav 2019; 9:e01428. [PMID: 31571393 PMCID: PMC6908857 DOI: 10.1002/brb3.1428] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/28/2019] [Accepted: 08/31/2019] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION Rodent primary sensory neurons are commonly used for studying itch and pain neurophysiology, but translation from rodents to larger mammals and humans is not direct and requires further validation to make correlations. METHODS This study developed a primary canine sensory neuron culture from dorsal root ganglia (DRG) excised from cadaver dogs. Additionally, the canine DRG cell cultures developed were used for single-cell ratiometric calcium imaging, with the activation of neurons to the following pruritogenic and algogenic substances: histamine, chloroquine, canine protease-activated receptor 2 (PAR2) activating peptide (SLIGKT), compound 48/80, 5-hydroxytryptamine receptor agonist (5-HT), bovine adrenal medulla peptide (BAM8-22), substance P, allyl isothiocyanate (AITC), and capsaicin. RESULTS This study demonstrates a simple dissection and rapid processing of DRG collected from canine cadavers used to create viable primary sensory neuron cultures to measure responses to pruritogens and algogens. CONCLUSION Ratiometric calcium imaging demonstrated that small-diameter canine sensory neurons can be activated by multiple stimuli, and a single neuron can react to both a pruritogenic stimulation and an algogenic stimulation.
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Affiliation(s)
- Joy Rachel C Ganchingco
- Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, USA
| | - Tomoki Fukuyama
- Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, USA.,Laboratory of Veterinary Pharmacology, Azabu University, Kanagawa, Japan
| | - Jeffrey A Yoder
- Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, USA
| | - Wolfgang Bäumer
- Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, USA.,Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
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44
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The emergence of animal models of chronic pain and logistical and methodological issues concerning their use. J Neural Transm (Vienna) 2019; 127:393-406. [DOI: 10.1007/s00702-019-02103-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 11/07/2019] [Indexed: 12/12/2022]
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45
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Ge C, Huang H, Huang F, Yang T, Zhang T, Wu H, Zhou H, Chen Q, Shi Y, Sun Y, Liu L, Wang X, Pearson RB, Cao Y, Kang J, Fu C. Neurokinin-1 receptor is an effective target for treating leukemia by inducing oxidative stress through mitochondrial calcium overload. Proc Natl Acad Sci U S A 2019; 116:19635-19645. [PMID: 31488714 PMCID: PMC6765257 DOI: 10.1073/pnas.1908998116] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Substance P (SP) regulates multiple biological processes through its high-affinity neurokinin-1 receptor (NK-1R). While the SP/NK-1R signaling axis is involved in the pathogenesis of solid cancer, the role of this signaling pathway in hematological malignancy remains unknown. Here, we demonstrate that NK-1R expression is markedly elevated in the white blood cells from acute myeloid leukemia patients and a panel of human leukemia cell lines. Blocking NK-1R induces apoptosis in vitro and in vivo via increase of mitochondrial reactive oxygen species. This oxidative stress was triggered by rapid calcium flux from the endoplasmic reticulum into mitochondria and, consequently, impairment of mitochondrial function, a mechanism underlying the cytotoxicity of NK-1R antagonists. Besides anticancer activity, blocking NK-1R produces a potent antinociceptive effect in myeloid leukemia-induced bone pain by alleviating inflammation and inducing apoptosis. These findings thus raise the exciting possibility that the NK-1R antagonists, drugs currently used in the clinic for preventing chemotherapy-induced nausea and vomiting, may provide a therapeutic option for treating human myeloid leukemia.
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Affiliation(s)
- Chentao Ge
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, 310018 Hangzhou, China
| | - Hemiao Huang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, 310018 Hangzhou, China
| | - Feiyan Huang
- Clinical Laboratory, Zhejiang Provincial Hospital of TCM, 310006 Hangzhou, China
| | - Tianxin Yang
- Department of Hematology, Zhejiang Province People's Hospital, 310014 Hangzhou, China
| | - Tengfei Zhang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, 310018 Hangzhou, China
| | - Hongzhang Wu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, 310018 Hangzhou, China
| | - Hanwei Zhou
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, 310018 Hangzhou, China
| | - Qi Chen
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, 310018 Hangzhou, China
| | - Yue Shi
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, 310018 Hangzhou, China
| | - Yanfang Sun
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, 310018 Hangzhou, China
| | - Liangjue Liu
- Clinical Laboratory, Zhejiang Provincial Hospital of TCM, 310006 Hangzhou, China
| | - Xi Wang
- Department of Oncology, The People's Liberation Army No. 903rd Hospital, 310013 Hangzhou, China
| | - Richard B Pearson
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia;
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Yihai Cao
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Jian Kang
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia;
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3000, Australia
| | - Caiyun Fu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, 310018 Hangzhou, China;
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46
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Yu H, Zhao T, Liu S, Wu Q, Johnson O, Wu Z, Zhuang Z, Shi Y, Peng L, He R, Yang Y, Sun J, Wang X, Xu H, Zeng Z, Zou P, Lei X, Luo W, Li Y. MRGPRX4 is a bile acid receptor for human cholestatic itch. eLife 2019; 8:48431. [PMID: 31500698 PMCID: PMC6773440 DOI: 10.7554/elife.48431] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 09/02/2019] [Indexed: 02/06/2023] Open
Abstract
Patients with liver diseases often suffer from chronic itch, yet the pruritogen(s) and receptor(s) remain largely elusive. Here, we identify bile acids as natural ligands for MRGPRX4. MRGPRX4 is expressed in human dorsal root ganglion (hDRG) neurons and co-expresses with itch receptor HRH1. Bile acids elicited Ca2+ responses in cultured hDRG neurons, and bile acids or a MRGPRX4 specific agonist induced itch in human subjects. However, a specific agonist for another bile acid receptor TGR5 failed to induce itch in human subjects and we find that human TGR5 is not expressed in hDRG neurons. Finally, we show positive correlation between cholestatic itch and plasma bile acids level in itchy patients and the elevated bile acids is sufficient to activate MRGPRX4. Taken together, our data strongly suggest that MRGPRX4 is a novel bile acid receptor that likely underlies cholestatic itch in human, providing a promising new drug target for anti-itch therapies.
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Affiliation(s)
- Huasheng Yu
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
| | - Tianjun Zhao
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
| | - Simin Liu
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Qinxue Wu
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Omar Johnson
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Zhaofa Wu
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China
| | - Zihao Zhuang
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Yaocheng Shi
- Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Luxin Peng
- Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Renxi He
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China
| | - Yong Yang
- Department of Dermatology, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Peking University First Hospital, Peking University, Beijing, China
| | - Jianjun Sun
- Department of Neurosurgery, Peking University Third Hospital, Peking University, Beijing, China
| | - Xiaoqun Wang
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Haifeng Xu
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Zheng Zeng
- Department of Infectious Diseases, Peking University First Hospital, Beijing, China
| | - Peng Zou
- Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Xiaoguang Lei
- Peking-Tsinghua Center for Life Sciences, Beijing, China.,Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Wenqin Luo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China.,Chinese Institute for Brain Research, Beijing, China
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47
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Wang Y, Lei J, Jha RK, Kiven S, Gupta K. Substance P modulates electroacupuncture analgesia in humanized mice with sickle cell disease. J Pain Res 2019; 12:2419-2426. [PMID: 31447579 PMCID: PMC6682765 DOI: 10.2147/jpr.s210196] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 06/05/2019] [Indexed: 01/22/2023] Open
Abstract
Purpose: Chronic pain is a major comorbidity of sickle cell disease (SCD). Acupuncture, a non-opioid and non-addictive therapy to treat pain, was found to reduce pain in the majority (80%) of SCD patients in an earlier retrospective review. We observed that electroacupuncture (EA) decreased hyperalgesia in transgenic mice with SCD with varied analgesia from high to moderate to no response. Interestingly, poor responders exhibited high levels of substance P (SP), a mediator of chronic pain, as well as active p38 MAPK in spinal cords. The present study aimed to investigate the roles of inhibition of SP and SP-activated p38 MAPK in chronic pain in sickle mice that are poorly responsive to EA intervention (moderate/non-responders). Materials and methods: Humanized mouse model with SCD defined as moderate- and non-responders to EA were intraperitoneally administered with antagonist of SP receptor NK1R (netupitant, 10 mg/kg/day, i.p.) or p38 MAPK inhibitor (SB203580, 10 mg/kg/day, i.p.) alone or in combination with EA (acupoint GB30, every 3rd day until day 12). Hyperalgesia to mechanical, thermal and cold stimuli, as well as deep tissue were measured. Phosphorylated p38 MAPK (phospho-p38 MAPK) in the lumbar spinal cord was quantified using western blotting. Phospho-p38 MAPK nuclear translocation in spinal dorsal horn was examined using immunohistochemical staining and confocal microscopy. Results: In EA poor-responders, combined treatment with EA and netupitant significantly enhanced the analgesic effects of EA in poor-responders on mechanical, heat, cold, and deep tissue pain, and decreased phosphorylation of p38 MAPK in lumbar spinal cords and its nuclear translocation in the spinal dorsal horn. Furthermore, combined treatment with EA and SB203580 significantly improved analgesic effects of EA on mechanical and heat hyperalgesia, but not cold or deep tissue hyperalgesia. However, additional EA treatment only, or administration of either netupitant or SB203580 alone did not lead to analgesic effects. Conclusions: These results suggest a pivotal role of SP in maintaining the chronic pain in SCD via spinal phospho-p38 MAPK signaling, which may hinder the effect of EA in poor responders. Inhibition of SP signaling pathway or activity of p38 MAPK significantly improved the EA analgesia In EA poor-responders with SCD, which provides a promising way to treat the chronic pain in patients with SCD.
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Affiliation(s)
- Ying Wang
- Vascular Biology Center, Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Jianxun Lei
- Vascular Biology Center, Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Ritu K Jha
- Vascular Biology Center, Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Stacy Kiven
- Vascular Biology Center, Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Kalpna Gupta
- Vascular Biology Center, Division of Hematology, Oncology and Transplantation, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
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48
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Haberberger RV, Barry C, Dominguez N, Matusica D. Human Dorsal Root Ganglia. Front Cell Neurosci 2019; 13:271. [PMID: 31293388 PMCID: PMC6598622 DOI: 10.3389/fncel.2019.00271] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/04/2019] [Indexed: 12/14/2022] Open
Abstract
Sensory neurons with cell bodies situated in dorsal root ganglia convey information from external or internal sites of the body such as actual or potential harm, temperature or muscle length to the central nervous system. In recent years, large investigative efforts have worked toward an understanding of different types of DRG neurons at transcriptional, translational, and functional levels. These studies most commonly rely on data obtained from laboratory animals. Human DRG, however, have received far less investigative focus over the last 30 years. Nevertheless, knowledge about human sensory neurons is critical for a translational research approach and future therapeutic development. This review aims to summarize both historical and emerging information about the size and location of human DRG, and highlight advances in the understanding of the neurochemical characteristics of human DRG neurons, in particular nociceptive neurons.
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Affiliation(s)
- Rainer Viktor Haberberger
- Pain and Pulmonary Neurobiology Laboratory, Centre for Neuroscience, Anatomy and Histology, Flinders University, Adelaide, SA, Australia.,Órama Institute, Flinders University, Adelaide, SA, Australia
| | - Christine Barry
- Pain and Pulmonary Neurobiology Laboratory, Centre for Neuroscience, Anatomy and Histology, Flinders University, Adelaide, SA, Australia
| | - Nicholas Dominguez
- Pain and Pulmonary Neurobiology Laboratory, Centre for Neuroscience, Anatomy and Histology, Flinders University, Adelaide, SA, Australia
| | - Dusan Matusica
- Pain and Pulmonary Neurobiology Laboratory, Centre for Neuroscience, Anatomy and Histology, Flinders University, Adelaide, SA, Australia.,Órama Institute, Flinders University, Adelaide, SA, Australia
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North RY, Li Y, Ray P, Rhines LD, Tatsui CE, Rao G, Johansson CA, Zhang H, Kim YH, Zhang B, Dussor G, Kim TH, Price TJ, Dougherty PM. Electrophysiological and transcriptomic correlates of neuropathic pain in human dorsal root ganglion neurons. Brain 2019; 142:1215-1226. [PMID: 30887021 PMCID: PMC6487328 DOI: 10.1093/brain/awz063] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/27/2018] [Accepted: 01/27/2019] [Indexed: 02/06/2023] Open
Abstract
Neuropathic pain encompasses a diverse array of clinical entities affecting 7-10% of the population, which is challenging to adequately treat. Several promising therapeutics derived from molecular discoveries in animal models of neuropathic pain have failed to translate following unsuccessful clinical trials suggesting the possibility of important cellular-level and molecular differences between animals and humans. Establishing the extent of potential differences between laboratory animals and humans, through direct study of human tissues and/or cells, is likely important in facilitating translation of preclinical discoveries to meaningful treatments. Patch-clamp electrophysiology and RNA-sequencing was performed on dorsal root ganglia taken from patients with variable presence of radicular/neuropathic pain. Findings establish that spontaneous action potential generation in dorsal root ganglion neurons is associated with radicular/neuropathic pain and radiographic nerve root compression. Transcriptome analysis suggests presence of sex-specific differences and reveals gene modules and signalling pathways in immune response and neuronal plasticity related to radicular/neuropathic pain that may suggest therapeutic avenues and that has the potential to predict neuropathic pain in future cohorts.
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Affiliation(s)
- Robert Y North
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA
| | - Yan Li
- The Departments of Anesthesia and Pain Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA, USA
| | - Pradipta Ray
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Laurence D Rhines
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA, USA
| | - Claudio Esteves Tatsui
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA, USA
| | - Ganesh Rao
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA, USA
| | - Caj A Johansson
- The University of Texas Health Science Center, Houston, Texas, USA
| | - Hongmei Zhang
- The Departments of Anesthesia and Pain Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA, USA
| | - Yeun Hee Kim
- Department of Biological Sciences and Center for Systems Biology, The University of Texas at Dallas, Richardson, Texas, USA
| | - Bo Zhang
- Department of Biological Sciences and Center for Systems Biology, The University of Texas at Dallas, Richardson, Texas, USA
| | - Gregory Dussor
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Tae Hoon Kim
- Department of Biological Sciences and Center for Systems Biology, The University of Texas at Dallas, Richardson, Texas, USA
| | - Theodore J Price
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Patrick M Dougherty
- The Departments of Anesthesia and Pain Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA, USA
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