101
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Nascimento AI, Mar FM, Sousa MM. The intriguing nature of dorsal root ganglion neurons: Linking structure with polarity and function. Prog Neurobiol 2018; 168:86-103. [PMID: 29729299 DOI: 10.1016/j.pneurobio.2018.05.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 04/26/2018] [Accepted: 05/01/2018] [Indexed: 11/26/2022]
Abstract
Dorsal root ganglion (DRG) neurons are the first neurons of the sensory pathway. They are activated by a variety of sensory stimuli that are then transmitted to the central nervous system. An important feature of DRG neurons is their unique morphology where a single process -the stem axon- bifurcates into a peripheral and a central axonal branch, with different functions and cellular properties. Distinctive structural aspects of the two DRG neuron branches may have important implications for their function in health and disease. However, the link between DRG axonal branch structure, polarity and function has been largely neglected in the field, and relevant information is rather scattered across the literature. In particular, ultrastructural differences between the two axonal branches are likely to account for the higher transport and regenerative ability of the peripheral DRG neuron axon when compared to the central one. Nevertheless, the cell intrinsic factors contributing to this central-peripheral asymmetry are still unknown. Here we critically review the factors that may underlie the functional asymmetry between the peripheral and central DRG axonal branches. Also, we discuss the hypothesis that DRG neurons may assemble a structure resembling the axon initial segment that may be responsible, at least in part, for their polarity and electrophysiological features. Ultimately, we suggest that the clarification of the axonal ultrastructure of DRG neurons using state-of-the-art techniques will be crucial to understand the physiology of this peculiar cell type.
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Affiliation(s)
- Ana Isabel Nascimento
- Nerve Regeneration Group, Instituto de Biologia Molecular e Celular-IBMC and Instituto de Inovação e Investigação em Saúde, University of Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar-ICBAS, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Fernando Milhazes Mar
- Nerve Regeneration Group, Instituto de Biologia Molecular e Celular-IBMC and Instituto de Inovação e Investigação em Saúde, University of Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Mónica Mendes Sousa
- Nerve Regeneration Group, Instituto de Biologia Molecular e Celular-IBMC and Instituto de Inovação e Investigação em Saúde, University of Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.
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102
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Gonçalves NP, Vægter CB, Pallesen LT. Peripheral Glial Cells in the Development of Diabetic Neuropathy. Front Neurol 2018; 9:268. [PMID: 29770116 PMCID: PMC5940740 DOI: 10.3389/fneur.2018.00268] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 04/06/2018] [Indexed: 12/15/2022] Open
Abstract
The global prevalence of diabetes is rapidly increasing, affecting more than half a billion individuals within the next few years. As diabetes negatively affects several physiological systems, this dramatic increase represents not only impaired quality of life on the individual level but also a huge socioeconomic challenge. One of the physiological consequences affecting up to half of diabetic patients is the progressive deterioration of the peripheral nervous system, resulting in spontaneous pain and eventually loss of sensory function, motor weakness, and organ dysfunctions. Despite intense research on the consequences of hyperglycemia on nerve functions, the biological mechanisms underlying diabetic neuropathy are still largely unknown, and treatment options lacking. Research has mainly focused directly on the neuronal component, presumably from the perspective that this is the functional signal-transmitting unit of the nerve. However, it is noteworthy that each single peripheral sensory neuron is intimately associated with numerous glial cells; the neuronal soma is completely enclosed by satellite glial cells and the length of the longest axons covered by at least 1,000 Schwann cells. The glial cells are vital for the neuron, but very little is still known about these cells in general and especially how they respond to diabetes in terms of altered neuronal support. We will discuss current knowledge of peripheral glial cells and argue that increased research in these cells is imperative for a better understanding of the mechanisms underlying diabetic neuropathy.
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Affiliation(s)
- Nádia Pereira Gonçalves
- Department of Biomedicine, Nordic-EMBL Partnership for Molecular Medicine, Danish Research Institute of Translational Neuroscience (DANDRITE), Aarhus University, Aarhus, Denmark.,The International Diabetic Neuropathy Consortium (IDNC), Aarhus University, Aarhus, Denmark
| | - Christian Bjerggaard Vægter
- Department of Biomedicine, Nordic-EMBL Partnership for Molecular Medicine, Danish Research Institute of Translational Neuroscience (DANDRITE), Aarhus University, Aarhus, Denmark.,The International Diabetic Neuropathy Consortium (IDNC), Aarhus University, Aarhus, Denmark
| | - Lone Tjener Pallesen
- Department of Biomedicine, Nordic-EMBL Partnership for Molecular Medicine, Danish Research Institute of Translational Neuroscience (DANDRITE), Aarhus University, Aarhus, Denmark
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103
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George D, Ahrens P, Lambert S. Satellite glial cells represent a population of developmentally arrested Schwann cells. Glia 2018. [DOI: 10.1002/glia.23320] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Dale George
- Burnett School of Biomedical Sciences, College of Medicine; University of Central Florida; Orlando Florida
| | - Paige Ahrens
- Department of Medical Education, College of Medicine; University of Central Florida; Orlando Florida
| | - Stephen Lambert
- Department of Medical Education, College of Medicine; University of Central Florida; Orlando Florida
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104
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Sriperumbudur KK, Pau HW, van Rienen U. Effect of Tissue Heterogeneity on the Transmembrane Potential of Type-1 Spiral Ganglion Neurons: A Simulation Study. IEEE Trans Biomed Eng 2018; 65:658-668. [DOI: 10.1109/tbme.2017.2700361] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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105
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Furlan A, Adameyko I. Schwann cell precursor: a neural crest cell in disguise? Dev Biol 2018; 444 Suppl 1:S25-S35. [PMID: 29454705 DOI: 10.1016/j.ydbio.2018.02.008] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/14/2018] [Accepted: 02/14/2018] [Indexed: 01/19/2023]
Abstract
Schwann cell precursors (SCPs) are multipotent embryonic progenitors covering all developing peripheral nerves. These nerves grow and navigate with unprecedented precision, delivering SCP progenitors to almost all locations in the embryonic body. Within specific developing tissues, SCPs detach from nerves and generate neuroendocrine cells, autonomic neurons, mature Schwann cells, melanocytes and other cell types. These properties of SCPs evoke resemblances between them and their parental population, namely, neural crest cells. Neural crest cells are incredibly multipotent migratory cells that revolutionized the course of evolution in the lineage of early chordate animals. Given this similarity and recent data, it is possible to hypothesize that proto-neural crest cells are similar to SCPs spreading along the nerves. Here, we review the multipotency of SCPs, the signals that govern them, their potential therapeutic value, SCP's embryonic origin and their evolutionary connections. We dedicate this article to the memory of Wilhelm His, the father of the microtome and "Zwischenstrang", currently known as the neural crest.
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Affiliation(s)
- Alessandro Furlan
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724 USA
| | - Igor Adameyko
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden; Center for Brain Research, Medical University Vienna, 1090 Vienna, Austria.
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106
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Liu C, Li C, Deng Z, Du E, Xu C. Long Non-coding RNA BC168687 is Involved in TRPV1-mediated Diabetic Neuropathic Pain in Rats. Neuroscience 2018; 374:214-222. [PMID: 29421435 DOI: 10.1016/j.neuroscience.2018.01.049] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/22/2018] [Accepted: 01/24/2018] [Indexed: 02/08/2023]
Abstract
Long noncoding RNAs (lncRNAs) participate in a diverse range of molecular and biological processes, and dysregulation of lncRNAs has been observed in the pathogenesis of various human diseases. We observed alterations in mechanical withdrawal thresholds (MWT) and thermal withdrawal latencies (TWL) in streptozotocin (STZ)-induced diabetic rats treated with small interfering RNA (siRNA) of lncRNA BC168687. We detected expression of transient receptor potential vanilloid type 1 (TRPV1) in rat dorsal root ganglia (DRG) by a series of molecular experiments. We determined relative levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in rat serum by enzyme-linked immunosorbent assay (ELISA). In addition, we examined extracellular regulated protein kinases (ERK) and p38 mitogen-activated protein kinase (MAPK) signaling pathways by Western blot (WB). We showed that the MWT and TWL of diabetic rats increased significantly compared with control. Expression of TRPV1 receptors in DRG substantially decreased. Relative levels of TNF-α and IL-1β in the serum of lncRNA BC168687 siRNA-treated rats were reduced. Phosphorylation (p)-ERK and p-p38 signaling pathways in DRG were also decreased. Taken together, we concluded lncRNA BC168687 siRNA may alleviate TRPV1-mediated diabetic neuropathic pain.
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Affiliation(s)
- Chenglong Liu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, PR China
| | - Congcong Li
- The Second Clinical Medical College of Nanchang University, Nanchang 330006, PR China
| | - Zeyu Deng
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, PR China
| | - Errong Du
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, PR China
| | - Changshui Xu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang 330006, PR China.
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107
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Cholinergic responses of satellite glial cells in the superior cervical ganglia. Neurosci Lett 2018; 671:19-24. [PMID: 29391220 DOI: 10.1016/j.neulet.2018.01.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 01/01/2018] [Accepted: 01/25/2018] [Indexed: 11/21/2022]
Abstract
Satellite glial cells (SGCs) surround the neurons in sympathetic ganglia and are believed to make important contributions to the function of the ganglia under normal and pathological conditions. It has been proposed that SGCs communicate chemically with the neurons, but little is known about their pharmacological properties and there is no information on whether they respond to acetylcholine (ACh), which is the major neurotransmitter in these ganglia. We used calcium imaging to examine responses of SGCs in the mouse superior cervical ganglion to ACh. The SGCs responded to ACh (0.01-2 mM) with an elevation of intracellular Ca2+, which appeared to be due to direct action on these cells, as the response persisted in the presence of the nerve blocker tetrodotoxin (1 μM). The response was largely inhibited by atropine, indicating an action on muscarinic ACh receptors. In contrast to this, sensory ganglia (nodose and trigeminal) were not sensitive to ACh. Incubation of the ganglia in ACh (0.5 or 1 mM) increased the expression of glial fibrillay acidic protein, which is a marker for glial activation. Such incubation also increased the electrical coupling of SGCs, which is known to occur in sensory ganglia following injury. We conclude that SGCs in the superior cervical ganglia display muscarinic ACh receptors, which enable them to communicate chemically with the sympathetic neurons.
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108
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Meacham K, Shepherd A, Mohapatra DP, Haroutounian S. Neuropathic Pain: Central vs. Peripheral Mechanisms. Curr Pain Headache Rep 2018; 21:28. [PMID: 28432601 DOI: 10.1007/s11916-017-0629-5] [Citation(s) in RCA: 248] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE OF REVIEW Our goal is to examine the processes-both central and peripheral-that underlie the development of peripherally-induced neuropathic pain (pNP) and to highlight recent evidence for mechanisms contributing to its maintenance. While many pNP conditions are initiated by damage to the peripheral nervous system (PNS), their persistence appears to rely on maladaptive processes within the central nervous system (CNS). The potential existence of an autonomous pain-generating mechanism in the CNS creates significant implications for the development of new neuropathic pain treatments; thus, work towards its resolution is crucial. Here, we seek to identify evidence for PNS and CNS independently generating neuropathic pain signals. RECENT FINDINGS Recent preclinical studies in pNP support and provide key details concerning the role of multiple mechanisms leading to fiber hyperexcitability and sustained electrical discharge to the CNS. In studies regarding central mechanisms, new preclinical evidence includes the mapping of novel inhibitory circuitry and identification of the molecular basis of microglia-neuron crosstalk. Recent clinical evidence demonstrates the essential role of peripheral mechanisms, mostly via studies that block the initially damaged peripheral circuitry. Clinical central mechanism studies use imaging to identify potentially self-sustaining infra-slow CNS oscillatory activity that may be unique to pNP patients. While new preclinical evidence supports and expands upon the key role of central mechanisms in neuropathic pain, clinical evidence for an autonomous central mechanism remains relatively limited. Recent findings from both preclinical and clinical studies recapitulate the critical contribution of peripheral input to maintenance of neuropathic pain. Further clinical investigations on the possibility of standalone central contributions to pNP may be assisted by a reconsideration of the agreed terms or criteria for diagnosing the presence of central sensitization in humans.
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Affiliation(s)
- Kathleen Meacham
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Andrew Shepherd
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Durga P Mohapatra
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Simon Haroutounian
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA.
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA.
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109
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Bangash MA, Alles SRA, Santana-Varela S, Millet Q, Sikandar S, de Clauser L, Ter Heegde F, Habib AM, Pereira V, Sexton JE, Emery EC, Li S, Luiz AP, Erdos J, Gossage SJ, Zhao J, Cox JJ, Wood JN. Distinct transcriptional responses of mouse sensory neurons in models of human chronic pain conditions. Wellcome Open Res 2018. [PMID: 30079380 DOI: 10.12688/wellcomeopenres10.12688/wellcomeopenres.14641.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2023] Open
Abstract
Background: Sensory neurons play an essential role in almost all pain conditions, and have recently been classified into distinct subsets on the basis of their transcriptomes. Here we have analysed alterations in dorsal root ganglia (DRG) gene expression using microarrays in mouse models related to human chronic pain. Methods: Six different pain models were studied in male C57BL/6J mice: (1) bone cancer pain using cancer cell injection in the intramedullary space of the femur; (2) neuropathic pain using partial sciatic nerve ligation; (3) osteoarthritis pain using mechanical joint loading; (4) chemotherapy-induced pain with oxaliplatin; (5) chronic muscle pain using hyperalgesic priming; and (6) inflammatory pain using intraplantar complete Freund's adjuvant. Microarray analyses were performed using RNA isolated from dorsal root ganglia and compared to sham/vehicle treated controls. Results: Differentially expressed genes (DEGs) were identified. Known and previously unreported genes were found to be dysregulated in each pain model. The transcriptomic profiles for each model were compared and expression profiles of DEGs within subsets of DRG neuronal populations were analysed to determine whether specific neuronal subsets could be linked to each of the pain models. Conclusions: Each pain model exhibits a unique set of altered transcripts implying distinct cellular responses to different painful stimuli. No simple direct link between genetically distinct sets of neurons and particular pain models could be discerned.
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Affiliation(s)
- M A Bangash
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Sascha R A Alles
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Sonia Santana-Varela
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Queensta Millet
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Shafaq Sikandar
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Larissa de Clauser
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Freija Ter Heegde
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
- Comparative Biomedical Science, Skeletal Biology Group, Royal Veterinary College, London, NW1 0TU, UK
| | - Abdella M Habib
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
- College of Medicine, Member of Qatar Health Cluster, Qatar University, Doha, Qatar
| | - Vanessa Pereira
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Jane E Sexton
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Edward C Emery
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Shengnan Li
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Ana P Luiz
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Janka Erdos
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Samuel J Gossage
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - Jing Zhao
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - James J Cox
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, WC1E 6BT, UK
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110
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Yasko JR, Mains RE. Chronic pain following spinal cord injury: Current approaches to cellular and molecular mechanisms. TRENDS IN CELL & MOLECULAR BIOLOGY 2018; 13:67-84. [PMID: 33564218 PMCID: PMC7869846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Traumatic spinal cord injury (SCI) has devastating implications for patients, including a high prevalence of chronic pain. Despite advancements in our understanding of the mechanisms involved post-SCI, there are no effective treatments for chronic pain following injury. The development of new treatment interventions for pain is needed, but this requires improved models to assess injury-related cellular, neurophysiological and molecular changes in the spinal cord. Here, we will discuss recent animal models for SCI, molecular screening for altered patterns of gene expression, and the importance of injury severity and timing after SCI.
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111
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Pannese E. Biology and Pathology of Perineuronal Satellite Cells in Sensory Ganglia. BIOLOGY AND PATHOLOGY OF PERINEURONAL SATELLITE CELLS IN SENSORY GANGLIA 2018. [DOI: 10.1007/978-3-319-60140-3_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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112
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Chen Y, Huang LYM. A simple and fast method to image calcium activity of neurons from intact dorsal root ganglia using fluorescent chemical Ca 2+ indicators. Mol Pain 2017; 13:1744806917748051. [PMID: 29212403 PMCID: PMC5731619 DOI: 10.1177/1744806917748051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Chemical calcium indicators have been commonly used to monitor calcium (Ca2+) activity in cell bodies, i.e., somata, of isolated dorsal root ganglion neurons. Recent studies have shown that dorsal root ganglion somata play an essential role in soma–glia interactions and actively participate in the transmission of nociceptive signals. It is therefore desirable to develop methods to study Ca2+ activity in neurons and glia in intact dorsal root ganglia. In our previous studies, we found that incubation of intact dorsal root ganglia with acetoxymethyl dye resulted in efficient Ca2+ dye loading into glial cells but limited dye loading into neurons. Here, we introduce a useful method to load Ca2+ dyes in intact dorsal root ganglion neurons through electroporation. We found that electroporation greatly facilitated loading of Fluo-4 acetoxymethyl, Oregon green bapta-1-488 acetoxymethyl, and Fluo-4 pentapotassium salt into dorsal root ganglion neurons. In contrast, electroporation did not further facilitate dye loading into glia. Using electroporation followed by incubation of acetoxymethyl form Ca2+ dye, we can load acetoxymethyl Ca2+ dye well in both neurons and glia. With this approach, we found that inflammation induced by complete Freund’s adjuvant significantly increased the incidence of neuron–glia interactions in dorsal root ganglia. We also confirmed the actions of capsaicin and morphine on Ca2+ responses in dorsal root ganglion neurons. Thus, by promoting the loading of Ca2+ dye in neurons and glia through electroporation and incubation, Ca2+ activities in neurons and neuron–glia interactions can be well studied in intact dorsal root ganglia.
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Affiliation(s)
- Yong Chen
- 1 Department of Neuroscience, Cell Biology and Anatomy, 12338 University of Texas Medical Branch, Galveston , TX, USA
| | - Li-Yen M Huang
- 1 Department of Neuroscience, Cell Biology and Anatomy, 12338 University of Texas Medical Branch, Galveston , TX, USA
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113
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Leo M, Schmitt LI, Jastrow H, Thomale J, Kleinschnitz C, Hagenacker T. Cisplatin alters the function and expression of N-type voltage-gated calcium channels in the absence of morphological damage of sensory neurons. Mol Pain 2017; 13:1744806917746565. [PMID: 29166837 PMCID: PMC5731623 DOI: 10.1177/1744806917746565] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Platinum-based chemotherapeutic agents, such as cisplatin, are still frequently used for treating various types of cancer. Besides its high effectiveness, cisplatin has several serious side effects. One of the most common side effects is dorsal root ganglion (DRG) neurotoxicity. However, the mechanisms underlying this neurotoxicity are still unclear and controversially discussed. Cisplatin-mediated modulation of voltage-gated calcium channels (VGCCs) in the DRG neurons has been shown to alter intracellular calcium homeostasis, a process critical for the induction of neurotoxicity. Using the whole-cell patch-clamp technique, immunostaining, behavioural experiments and electron microscopy (EM) of rat DRGs, we here demonstrate that cisplatin-induced neurotoxicity is due to functional alteration of VGCC, but not due to morphological damage. In vitro application of cisplatin (0.5 µM) increased N-type VGCC currents (ICa(V)) in small DRG neurons. Repetitive in vivo administration of cisplatin (1.5 mg/kg, cumulative 12 mg/kg) increased the protein level of N-type VGCC over 26 days, with the protein level being increased for at least 14 days after the final cisplatin administration. Behavioural studies revealed that N-type VGCCs are crucial for inducing symptoms of cisplatin-related neuropathic pain, such as thermal and mechanical hyperalgesia. EM and histology showed no evidence of any structural damage, apoptosis or necrosis in DRG cells after cisplatin exposure for 26 days. Furthermore, no nuclear DNA damage in sensory neurons was observed. Here, we provide evidence for a mainly functionally driven induction of neuropathic pain by cisplatin.
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Affiliation(s)
- Markus Leo
- 1 Department of Neurology, University Hospital Essen, Essen, Germany
| | | | - Holger Jastrow
- 2 Institute of Anatomy, University Hospital Essen, Essen, Germany
| | - Jürgen Thomale
- 3 Institute for Cell Biology, University of Duisburg-Essen, Essen, Germany
| | | | - Tim Hagenacker
- 1 Department of Neurology, University Hospital Essen, Essen, Germany
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114
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Horton SM, Luna Lopez C, Blevins E, Howarth H, Weisberg J, Shestopalov VI, Makarenkova HP, Shah SB. Pannexin 1 Modulates Axonal Growth in Mouse Peripheral Nerves. Front Cell Neurosci 2017; 11:365. [PMID: 29213230 PMCID: PMC5702652 DOI: 10.3389/fncel.2017.00365] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/06/2017] [Indexed: 01/29/2023] Open
Abstract
The pannexin family of channels consists of three members—pannexin-1 (Panx1), pannexin-2 (Panx2), and pannexin-3 (Panx3) that enable the exchange of metabolites and signaling molecules between intracellular and extracellular compartments. Pannexin-mediated release of intracellular ATP into the extracellular space has been tied to a number of cellular activities, primarily through the activity of type P2 purinergic receptors. Previous work indicates that the opening of Panx1 channels and activation of purinergic receptors by extracellular ATP may cause inflammation and apoptosis. In the CNS (central nervous system) and PNS (peripheral nervous system), coupled pannexin, and P2 functions have been linked to peripheral sensitization (pain) pathways. Purinergic pathways are also essential for other critical processes in the PNS, including myelination and neurite outgrowth. However, whether such pathways are pannexin-dependent remains to be determined. In this study, we use a Panx1 knockout mouse model and pharmacological inhibitors of the Panx1 and the ATP-mediated signaling pathway to fill gaps in our understanding of Panx1 localization in peripheral nerves, roles for Panx1 in axonal outgrowth and myelination, and neurite extension. Our data show that Panx1 is localized to axonal, myelin, and vascular compartments of the peripheral nerves. Knockout of Panx1 gene significantly increased axonal caliber in vivo and axonal growth rate in cultured dorsal root ganglia (DRG) neurons. Furthermore, genetic knockout of Panx1 or inhibition of components of purinergic signaling, by treatment with probenecid and apyrase, resulted in denser axonal outgrowth from cultured DRG explants compared to untreated wild-types. Our findings suggest that Panx1 regulates axonal growth in the peripheral nervous system.
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Affiliation(s)
- Steven M Horton
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States
| | - Carlos Luna Lopez
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States
| | - Elisabeth Blevins
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, United States
| | - Holly Howarth
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States
| | - Jake Weisberg
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States
| | | | - Helen P Makarenkova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | - Sameer B Shah
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States.,Research Service, Veterans Affairs San Diego Healthcare System, San Diego, La Jolla, CA, United States.,Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States
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115
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Coutinho-Budd JC, Sheehan AE, Freeman MR. The secreted neurotrophin Spätzle 3 promotes glial morphogenesis and supports neuronal survival and function. Genes Dev 2017; 31:2023-2038. [PMID: 29138279 PMCID: PMC5733495 DOI: 10.1101/gad.305888.117] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/20/2017] [Indexed: 10/27/2022]
Abstract
Most glial functions depend on establishing intimate morphological relationships with neurons. Significant progress has been made in understanding neuron-glia signaling at synaptic and axonal contacts, but how glia support neuronal cell bodies is unclear. Here we explored the growth and functions of Drosophila cortex glia (which associate almost exclusively with neuronal cell bodies) to understand glia-soma interactions. We show that cortex glia tile with one another and with astrocytes to establish unique central nervous system (CNS) spatial domains that actively restrict glial growth, and selective ablation of cortex glia causes animal lethality. In an RNAi-based screen, we identified αSNAP (soluble NSF [N-ethylmalemeide-sensitive factor] attachment protein α) and several components of vesicle fusion and recycling machinery as essential for the maintenance of cortex glial morphology and continued contact with neurons. Interestingly, loss of the secreted neurotrophin Spätzle 3 (Spz3) phenocopied αSNAP phenotypes, which included loss of glial ensheathment of neuron cell bodies, increased neuronal cell death, and defects in animal behavior. Rescue experiments suggest that Spz3 can exert these effects only over very short distances. This work identifies essential roles for glial ensheathment of neuronal cell bodies in CNS homeostasis as well as Spz3 as a novel signaling factor required for maintenance of cortex glial morphology and neuron-glia contact.
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Affiliation(s)
- Jaeda C Coutinho-Budd
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Amy E Sheehan
- Vollum Institute, Oregon Health and Sciences University, Portland, Oregon 97239, USA
| | - Marc R Freeman
- Vollum Institute, Oregon Health and Sciences University, Portland, Oregon 97239, USA
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Chandrasekaran K, Muragundla A, Demarest TG, Choi J, Sagi AR, Najimi N, Kumar P, Singh A, Ho CY, Fiskum G, Koch LG, Britton SL, Russell JW. mGluR2/3 activation of the SIRT1 axis preserves mitochondrial function in diabetic neuropathy. Ann Clin Transl Neurol 2017; 4:844-858. [PMID: 29296613 PMCID: PMC5740254 DOI: 10.1002/acn3.484] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 08/24/2017] [Accepted: 08/30/2017] [Indexed: 12/15/2022] Open
Abstract
Objectives There is a critical need to develop effective treatments for diabetic neuropathy. This study determined if a selective mGluR2/3 receptor agonist prevented or treated experimental diabetic peripheral neuropathy (DPN) through glutamate recycling and improved mitochondrial function. Methods Adult male streptozotocin treated Sprague-Dawley rats with features of type 1 diabetes mellitus (T1DM) or Low Capacity Running (LCR) rats with insulin resistance or glucose intolerance were treated with 3 or 10 mg/kg/day LY379268. Neuropathy end points included mechanical allodynia, nerve conduction velocities (NCV), and intraepidermal nerve fiber density (IENFD). Markers of oxidative stress, antioxidant response, glutamate recycling pathways, and mitochondrial oxidative phosphorylation (OXPHOS) associated proteins were measured in dorsal root ganglia (DRG). Results In diabetic rats, NCV and IENFD were decreased. Diabetic rats treated with an mGluR2/3 agonist did not develop neuropathy despite remaining diabetic. Diabetic DRG showed increased levels of oxidized proteins, decreased levels of glutathione, decreased levels of mitochondrial DNA (mtDNA) and OXPHOS proteins. In addition, there was a 20-fold increase in levels of glial fibrillary acidic protein (GFAP) and the levels of glutamine synthetase and glutamate transporter proteins were decreased. When treated with a specific mGluR2/3 agonist, levels of glutathione, GFAP and oxidized proteins were normalized and levels of superoxide dismutase 2 (SOD2), SIRT1, PGC-1α, TFAM, glutamate transporter proteins, and glutamine synthetase were increased in DRG neurons. Interpretation Activation of glutamate recycling pathways protects diabetic DRG and this is associated with activation of the SIRT1-PGC-1α-TFAM axis and preservation of mitochondrial OXPHOS function.
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Affiliation(s)
- Krish Chandrasekaran
- Department of Neurology University of Maryland School of Medicine Baltimore Maryland 21201.,Veterans Affairs Medical Center Baltimore Maryland 21201
| | - Anjaneyulu Muragundla
- Department of Neurology University of Maryland School of Medicine Baltimore Maryland 21201.,Veterans Affairs Medical Center Baltimore Maryland 21201
| | - Tyler G Demarest
- Department Anesthesiology University of Maryland School of Medicine Baltimore Maryland 21201
| | - Joungil Choi
- Department of Neurology University of Maryland School of Medicine Baltimore Maryland 21201.,Veterans Affairs Medical Center Baltimore Maryland 21201
| | - Avinash R Sagi
- Department of Neurology University of Maryland School of Medicine Baltimore Maryland 21201
| | - Neda Najimi
- Department of Neurology University of Maryland School of Medicine Baltimore Maryland 21201
| | - Pranith Kumar
- Department of Neurology University of Maryland School of Medicine Baltimore Maryland 21201
| | - Anmol Singh
- Department of Neurology University of Maryland School of Medicine Baltimore Maryland 21201
| | - Cheng-Ying Ho
- Department Pathology University of Maryland School of Medicine Baltimore Maryland 21201
| | - Gary Fiskum
- Department Anesthesiology University of Maryland School of Medicine Baltimore Maryland 21201
| | - Lauren G Koch
- Department of Anesthesiology University of Michigan Ann Arbor Michigan 48109
| | - Steven L Britton
- Department of Anesthesiology University of Michigan Ann Arbor Michigan 48109.,Department of Molecular and Integrative Physiology University of Michigan Ann Arbor Michigan 48109
| | - James W Russell
- Department of Neurology University of Maryland School of Medicine Baltimore Maryland 21201.,Veterans Affairs Medical Center Baltimore Maryland 21201.,Anatomy and Neurobiology University of Maryland School of Medicine Baltimore Maryland 21201
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117
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Abstract
How primary sensory neurons contribute to persistent pain remains unclear. A novel imaging technique introduced here by Kim et al. (2016) in this issue of Neuron to view the activities of large numbers of ganglion neurons simultaneously analyzes the importance of neuronal cross-talk in pain transmission.
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118
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Sugawara S, Okada S, Katagiri A, Saito H, Suzuki T, Komiya H, Kanno K, Ohara K, Iinuma T, Toyofuku A, Iwata K. Interaction between calcitonin gene-related peptide-immunoreactive neurons and satellite cells via P2Y 12 R in the trigeminal ganglion is involved in neuropathic tongue pain in rats. Eur J Oral Sci 2017; 125:444-452. [PMID: 29023985 DOI: 10.1111/eos.12382] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The P2Y12 receptor expressed in satellite cells of the trigeminal ganglion is thought to contribute to neuropathic pain. The functional interaction between neurons and satellite cells via P2Y12 receptors and phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) underlying neuropathic pain in the tongue was evaluated in this study. Expression of P2Y12 receptor was enhanced in pERK1/2-immunoreactive cells encircling trigeminal ganglion neurons after lingual nerve crush. The administration to lingual nerve crush rats of a selective P2Y12 receptor antagonist, MRS2395, attenuated tongue hypersensitivity to mechanical and heat stimulation and suppressed the increase in the relative numbers of calcitonin gene-related peptide (CGRP)-immunoreactive neurons and neurons encircled by pERK1/2-immunoreactive cells. Administration of the P2Y1,12,13 receptor agonist, 2-(methylthio)adenosine 5'-diphosphate trisodium salt hydrate (2-MeSADP), to naïve rats induced neuropathic pain in the tongue, as in lingual nerve crush rats. Co-administration of 2-MeSADP + MRS2395 to naïve rats did not result in hypersensitivity of the tongue. The relative number of CGRP-immunoreactive neurons increased following this co-administration, but to a lesser degree than observed in 2-MeSADP-administrated naïve rats, and the relative number of neurons encircled by pERK1/2-immunoreactive cells did not change. These results suggest that the interaction between activated satellite cells and CGRP-immunoreactive neurons via P2Y12 receptors contributes to neuropathic pain in the tongue associated with lingual nerve injury.
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Affiliation(s)
- Shiori Sugawara
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan.,Department of Psychosomatic Dentistry, Tokyo Medical and Dental University (TMDU) Graduate School, Bunkyo-ku, Tokyo, Japan
| | - Shinji Okada
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan.,Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
| | - Ayano Katagiri
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
| | - Hiroto Saito
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan.,Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
| | - Tatsuro Suzuki
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan.,Department of Periodontics, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
| | - Hiroki Komiya
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan.,Department of Endodontics, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
| | - Kohei Kanno
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan.,Department of Endodontics, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
| | - Kinuyo Ohara
- Department of Endodontics, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
| | - Toshimitsu Iinuma
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
| | - Akira Toyofuku
- Department of Psychosomatic Dentistry, Tokyo Medical and Dental University (TMDU) Graduate School, Bunkyo-ku, Tokyo, Japan
| | - Koichi Iwata
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
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119
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Lopes DM, Denk F, McMahon SB. The Molecular Fingerprint of Dorsal Root and Trigeminal Ganglion Neurons. Front Mol Neurosci 2017; 10:304. [PMID: 29018326 PMCID: PMC5623188 DOI: 10.3389/fnmol.2017.00304] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 09/11/2017] [Indexed: 12/15/2022] Open
Abstract
The dorsal root ganglia (DRG) and trigeminal ganglia (TG) are clusters of cell bodies of highly specialized sensory neurons which are responsible for relaying information about our environment to the central nervous system. Despite previous efforts to characterize sensory neurons at the molecular level, it is still unknown whether those present in DRG and TG have distinct expression profiles and therefore a unique molecular fingerprint. To address this question, we isolated lumbar DRG and TG neurons using fluorescence-activated cell sorting from Advillin-GFP transgenic mice and performed RNA sequencing. Our transcriptome analyses showed that, despite being overwhelmingly similar, a number of genes are differentially expressed in DRG and TG neurons. Importantly, we identified 24 genes which were uniquely expressed in either ganglia, including an arginine vasopressin receptor and several homeobox genes, giving each population a distinct molecular fingerprint. We compared our findings with published studies to reveal that many genes previously reported to be present in neurons are in fact likely to originate from other cell types in the ganglia. Additionally, our neuron-specific results aligned well with a dataset examining whole human TG and DRG. We propose that the data can both improve our understanding of primary afferent biology and help contribute to the development of drug treatments and gene therapies which seek targets with unique or restricted expression patterns.
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Affiliation(s)
- Douglas M Lopes
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Franziska Denk
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Stephen B McMahon
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
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120
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Xiang H, Xu H, Fan F, Shin SM, Hogan QH, Yu H. Glial fibrillary acidic protein promoter determines transgene expression in satellite glial cells following intraganglionic adeno-associated virus delivery in adult rats. J Neurosci Res 2017; 96:436-448. [PMID: 28941260 DOI: 10.1002/jnr.24183] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/25/2017] [Accepted: 09/05/2017] [Indexed: 12/24/2022]
Abstract
Recombinant adeno-associated viral (AAV)-mediated therapeutic gene transfer to dorsal root ganglia (DRG) is an effective and safe tool for treating chronic pain. However, AAV with various constitutively active promoters leads to transgene expression predominantly to neurons, while glial cells are refractory to AAV transduction in the peripheral nervous system. The present study evaluated whether in vivo satellite glial cell (SGC) transduction in the DRG can be enhanced by the SGC-specific GFAP promoter and by using shH10 and shH19, which are engineered capsid variants with Müller glia-prone transduction. Titer-matched AAV6 (as control), AAVshH10, and AAVshH19, all encoding the EGFP driven by the constitutively active CMV promoter, as well as AAV6-EGFP and AAVshH10-EGFP driven by a GFAP promoter (AAV6-GFAP-EGFP and AAVshH10-GFAP-EGFP), were injected into DRG of adult male rats. Neurotropism of gene expression was determined and compared by immunohistochemistry. Results showed that injection of AAV6- and AAVshH10-GFAP-EGFP induces robust EGFP expression selectively in SGCs, whereas injection of either AAVshH10-CMV-EGFP or AAVshH19-CMV-EGFP into DRG resulted in a similar in vivo transduction profile to AAV6-CMV-EGFP, all showing efficient transduction of sensory neurons without significant transduction of glial cell populations. Coinjection of AAV6-CMV-mCherry and AAV6-GFAP-EGFP induces transgene expression in neurons and SGCs separately. This report, together with our prior studies, demonstrates that the GFAP promoter rather than capsid tropism determines selective gene expression in SGCs following intraganglionic AAV delivery in adult rats. A dual AAV system, one with GFAP promoter and the other with CMV promoter, can efficiently express transgenes selectively in neurons versus SGCs.
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Affiliation(s)
- Hongfei Xiang
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Orthopedic Surgery, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Hao Xu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Orthopedic Surgery, Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Fan Fan
- Department of Pharmacology and Toxicology, Mississippi University Medical Center, Jackson, Mississippi
| | - Seung-Min Shin
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Quinn H Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Hongwei Yu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
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121
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Salavatian S, Beaumont E, Gibbons D, Hammer M, Hoover DB, Armour JA, Ardell JL. Thoracic spinal cord and cervical vagosympathetic neuromodulation obtund nodose sensory transduction of myocardial ischemia. Auton Neurosci 2017; 208:57-65. [PMID: 28919363 DOI: 10.1016/j.autneu.2017.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/07/2017] [Accepted: 08/16/2017] [Indexed: 12/01/2022]
Abstract
BACKGROUND Autonomic regulation therapy involving either vagus nerve stimulation (VNS) or spinal cord stimulation (SCS) represents emerging bioelectronic therapies for heart disease. The objective of this study was to determine if VNS and/or SCS modulate primary cardiac afferent sensory transduction of the ischemic myocardium. METHODS Using extracellular recordings in 19 anesthetized canines, of 88 neurons evaluated, 36 ventricular-related nodose ganglia sensory neurons were identified by their functional activity responses to epicardial touch, chemical activation of their sensory neurites (epicardial veratridine) and great vessel (descending aorta or inferior vena cava) occlusion. Neural responses to 1min left anterior descending (LAD) coronary artery occlusion (CAO) were then evaluated. These interventions were then studied following either: i) SCS [T1-T3 spinal level; 50Hz, 90% motor threshold] or ii) cervical VNS [15-20Hz; 1.2× threshold]. RESULTS LAD occlusion activated 66% of identified nodose ventricular sensory neurons (0.33±0.08-0.79±0.20Hz; baseline to CAO; p<0.002). Basal activity of cardiac-related nodose neurons was differentially reduced by VNS (0.31±0.11 to 0.05±0.02Hz; p<0.05) as compared to SCS (0.36±0.12 to 0.28±0.14, p=0.59), with their activity response to transient LAD CAO being suppressed by either SCS (0.85±0.39-0.11±0.04Hz; p<0.03) or VNS (0.75±0.27-0.12±0.05Hz; p<0.04). VNS did not alter evoked neural responses of cardiac-related nodose neurons to great vessel occlusion. CONCLUSIONS Both VNS and SCS obtund ventricular ischemia induced enhancement of nodose afferent neuronal inputs to the medulla.
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Affiliation(s)
- Siamak Salavatian
- UCLA Neurocardiology Research Program of Excellence, Los Angeles, CA, United States; UCLA Cardiac Arrhythmia Center, Los Angeles, CA, United States
| | - Eric Beaumont
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, United States; Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, United States
| | - David Gibbons
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, United States
| | - Matthew Hammer
- UCLA Neurocardiology Research Program of Excellence, Los Angeles, CA, United States
| | - Donald B Hoover
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, United States; Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, Johnson City, TN, United States
| | - J Andrew Armour
- UCLA Neurocardiology Research Program of Excellence, Los Angeles, CA, United States; UCLA Cardiac Arrhythmia Center, Los Angeles, CA, United States
| | - Jeffrey L Ardell
- UCLA Neurocardiology Research Program of Excellence, Los Angeles, CA, United States; UCLA Cardiac Arrhythmia Center, Los Angeles, CA, United States.
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122
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Lu R, Flauaus C, Kennel L, Petersen J, Drees O, Kallenborn-Gerhardt W, Ruth P, Lukowski R, Schmidtko A. K Ca3.1 channels modulate the processing of noxious chemical stimuli in mice. Neuropharmacology 2017; 125:386-395. [PMID: 28823609 DOI: 10.1016/j.neuropharm.2017.08.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/26/2017] [Accepted: 08/16/2017] [Indexed: 12/19/2022]
Abstract
Intermediate conductance calcium-activated potassium channels (KCa3.1) have been recently implicated in pain processing. However, the functional role and localization of KCa3.1 in the nociceptive system are largely unknown. We here characterized the behavior of mice lacking KCa3.1 (KCa3.1-/-) in various pain models and analyzed the expression pattern of KCa3.1 in dorsal root ganglia (DRG) and the spinal cord. KCa3.1-/- mice demonstrated normal behavioral responses in models of acute nociceptive, persistent inflammatory, and persistent neuropathic pain. However, their behavioral responses to noxious chemical stimuli such as formalin and capsaicin were increased. Accordingly, formalin-induced nociceptive behavior was increased in wild-type mice after administration of the KCa3.1 inhibitor TRAM-34. In situ hybridization experiments detected KCa3.1 in most DRG satellite glial cells, in a minority of DRG neurons, and in ependymal cells lining the central canal of the spinal cord. Together, our data point to a specific inhibitory role of KCa3.1 for the processing of noxious chemical stimuli.
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Affiliation(s)
- Ruirui Lu
- Pharmakologisches Institut für Naturwissenschaftler, Goethe-Universität, Fachbereich Biochemie, Chemie und Pharmazie, 60438 Frankfurt am Main, Germany; Institut für Pharmakologie und Toxikologie, Universität Witten/Herdecke, ZBAF, 58453 Witten, Germany.
| | - Cathrin Flauaus
- Pharmakologisches Institut für Naturwissenschaftler, Goethe-Universität, Fachbereich Biochemie, Chemie und Pharmazie, 60438 Frankfurt am Main, Germany
| | - Lea Kennel
- Pharmakologisches Institut für Naturwissenschaftler, Goethe-Universität, Fachbereich Biochemie, Chemie und Pharmazie, 60438 Frankfurt am Main, Germany
| | - Jonas Petersen
- Pharmakologisches Institut für Naturwissenschaftler, Goethe-Universität, Fachbereich Biochemie, Chemie und Pharmazie, 60438 Frankfurt am Main, Germany; Institut für Pharmakologie und Toxikologie, Universität Witten/Herdecke, ZBAF, 58453 Witten, Germany
| | - Oliver Drees
- Institut für Pharmakologie und Toxikologie, Universität Witten/Herdecke, ZBAF, 58453 Witten, Germany
| | - Wiebke Kallenborn-Gerhardt
- Pharmakologisches Institut für Naturwissenschaftler, Goethe-Universität, Fachbereich Biochemie, Chemie und Pharmazie, 60438 Frankfurt am Main, Germany
| | - Peter Ruth
- Pharmakologie, Toxikologie und Klinische Pharmazie, Institut für Pharmazie, Universität Tübingen, 72076 Tübingen, Germany
| | - Robert Lukowski
- Pharmakologie, Toxikologie und Klinische Pharmazie, Institut für Pharmazie, Universität Tübingen, 72076 Tübingen, Germany
| | - Achim Schmidtko
- Pharmakologisches Institut für Naturwissenschaftler, Goethe-Universität, Fachbereich Biochemie, Chemie und Pharmazie, 60438 Frankfurt am Main, Germany; Institut für Pharmakologie und Toxikologie, Universität Witten/Herdecke, ZBAF, 58453 Witten, Germany
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123
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Abstract
Enhanced expression and function of gap junctions and pannexin (Panx) channels have been associated with both peripheral and central mechanisms of pain sensitization. At the level of the sensory ganglia, evidence includes augmented gap junction and pannexin1 expression in glial cells and neurons in inflammatory and neuropathic pain models and increased synchrony and enhanced cross-excitation among sensory neurons by gap junction-mediated coupling. In spinal cord and in suprapinal areas, evidence is largely limited to increased expression of relevant proteins, although in several rodent pain models, hypersensitivity is reduced by treatment with gap junction/Panx1 channel blocking compounds. Moreover, targeted modulation of Cx43 expression was shown to modulate pain thresholds, albeit in somewhat contradictory ways, and mice lacking Panx1 expression globally or in specific cell types show depressed hyperalgesia. We here review the evidence for involvement of gap junctions and Panx channels in a variety of animal pain studies and then discuss ways in which gap junctions and Panx channels may mediate their action in pain processing. This discussion focusses on spread of signals among satellite glial cells, in particular intercellular Ca2+ waves, which are propagated through both gap junction and Panx1-dependent routes and have been associated with the phenomenon of spreading depression and the malady of migraine headache with aura.
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124
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Feldman-Goriachnik R, Hanani M. The effects of endothelin-1 on satellite glial cells in peripheral ganglia. Neuropeptides 2017; 63:37-42. [PMID: 28342550 DOI: 10.1016/j.npep.2017.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/01/2017] [Accepted: 03/16/2017] [Indexed: 11/21/2022]
Abstract
Endothelins (ET) are a family of highly active neuropeptides with manifold influences via ET receptors (ETR) in both the peripheral and central nervous systems. We have shown previously that satellite glial cells (SGCs) in mouse trigeminal ganglia (TG) are extremely sensitive to ET-1 in evoking [Ca2+]in increase, apparently via ETBR activation, but there is no functional information on ETR in SGCs of other peripheral ganglia. Here we tested the effects of ET-1 on SGCs in nodose ganglia (NG), which is sensory, and superior cervical ganglia (Sup-CG), which is part of the sympathetic nervous system, and further investigated the influence of ET-1 on SGCs in TG. Using calcium imaging we found that SGCs in intact, freshly isolated NG and Sup-CG are highly sensitive to ET-1, with threshold concentration at 0.1nM. Our results showed that [Ca2+]in elevation in response to ET-1 was partially due to Ca2+ influx from the extracellular space and partially to Ca2+ release from intracellular stores. Using receptor selective ETR agonists and antagonists, we found that the responses were mediated by mixed ETAR/ETBR in SGCs of NG and predominantly by ETBR in SGCs of Sup-CG. By employing intracellular dye injection we examined coupling among SGCs around different neurons in the presence of 5nM ET-1 and observed coupling inhibition in all the three ganglion types. In summary, our work showed that SGCs in mouse sensory and sympathetic ganglia are highly sensitive to ET-1 and that this peptide markedly reduces SGCs coupling. We conclude that ET-1, which may participate in neuron-glia communications, has similar functions in wide range of peripheral ganglia.
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Affiliation(s)
- Rachel Feldman-Goriachnik
- Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem 91240, Israel
| | - Menachem Hanani
- Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem 91240, Israel.
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125
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Scemes E, Velíšková J. Exciting and not so exciting roles of pannexins. Neurosci Lett 2017; 695:25-31. [PMID: 28284836 DOI: 10.1016/j.neulet.2017.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/02/2017] [Accepted: 03/06/2017] [Indexed: 01/24/2023]
Abstract
It is the current view that purinergic signaling regulates many physiological functions. Pannexin1 (Panx1), a member of the gap junction family of proteins is an ATP releasing channel that plays important physio-pathological roles in various tissues, including the CNS. Upon binding to purinergic receptors expressed in neural cells, ATP triggers cellular responses including increased cell proliferation, cell morphology changes, release of cytokines, and regulation of neuronal excitability via release of glutamate, GABA and ATP itself. Under pathological conditions such as ischemia, trauma, inflammation, and epilepsy, extracellular ATP concentrations increases drastically but the consequences of this surge is still difficult to characterize due to its rapid metabolism in ADP and adenosine, the latter having inhibitory action on neuronal activity. For seizures, for instance, the excitatory effect of ATP on neuronal activity is mainly related to its action of P2X receptors, while the inhibitory effects are related to activation of P1, adenosine receptors. Here we provide a mini review on the properties of pannexins with a main focus on Panx1 and its involvement in seizure activity. Although there are only few studies implicating Panx1 in seizures, they are illustrative of the dual role that Panx1 has on neuronal excitability.
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Affiliation(s)
- Eliana Scemes
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
| | - Jana Velíšková
- Departments of Cell Biology & Anatomy, Obstetrics & Gynecology and Neurology, New York Medical College, Valhalla, NY, 10595, USA.
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126
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Gonçalves NP, Vægter CB, Andersen H, Østergaard L, Calcutt NA, Jensen TS. Schwann cell interactions with axons and microvessels in diabetic neuropathy. Nat Rev Neurol 2017; 13:135-147. [PMID: 28134254 DOI: 10.1038/nrneurol.2016.201] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The prevalence of diabetes worldwide is at pandemic levels, with the number of patients increasing by 5% annually. The most common complication of diabetes is peripheral neuropathy, which has a prevalence as high as 50% and is characterized by damage to neurons, Schwann cells and blood vessels within the nerve. The pathogenic mechanisms of diabetic neuropathy remain poorly understood, impeding the development of targeted therapies to treat nerve degeneration and its most disruptive consequences of sensory loss and neuropathic pain. Involvement of Schwann cells has long been proposed, and new research techniques are beginning to unravel a complex interplay between these cells, axons and microvessels that is compromised during the development of diabetic neuropathy. In this Review, we discuss the evolving concept of Schwannopathy as an integral factor in the pathogenesis of diabetic neuropathy, and how disruption of the interactions between Schwann cells, axons and microvessels contribute to the disease.
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Affiliation(s)
- Nádia P Gonçalves
- The International Diabetic Neuropathy Consortium (IDNC), Aarhus University, Nørrebrogade, 8000 Aarhus C, Denmark
| | - Christian B Vægter
- Danish Research Institute of Translational Neuroscience DANDRITE, Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Ole Worms Alle 3, 8000 Aarhus C, Denmark
| | - Henning Andersen
- Department of Neurology, Danish Pain Research Center and IDNC, Aarhus University Hospital, Nørrebrogade, 8000 Aarhus C, Denmark
| | - Leif Østergaard
- Department of Neuroradiology and Center for Functionally Integrative Neuroscience, Aarhus University Hospital, Nørrebrogade, 8000 Aarhus C, Denmark
| | - Nigel A Calcutt
- Department of Pathology, University of California San Diego, Gilman Drive, La Jolla, California 92093, USA
| | - Troels S Jensen
- Department of Neurology, Danish Pain Research Center and IDNC, Aarhus University Hospital, Nørrebrogade, 8000 Aarhus C, Denmark
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Walters ET. How is chronic pain related to sympathetic dysfunction and autonomic dysreflexia following spinal cord injury? Auton Neurosci 2017; 209:79-89. [PMID: 28161248 DOI: 10.1016/j.autneu.2017.01.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/24/2017] [Accepted: 01/25/2017] [Indexed: 12/29/2022]
Abstract
Autonomic dysreflexia (AD) and neuropathic pain occur after severe injury to higher levels of the spinal cord. Mechanisms underlying these problems have rarely been integrated in proposed models of spinal cord injury (SCI). Several parallels suggest significant overlap of these mechanisms, although the relationships between sympathetic function (dysregulated in AD) and nociceptive function (dysregulated in neuropathic pain) are complex. One general mechanism likely to be shared is central sensitization - enhanced responsiveness and synaptic reorganization of spinal circuits that mediate sympathetic reflexes or that process and relay pain-related information to the brain. Another is enhanced sensory input to spinal circuits caused by extensive alterations in primary sensory neurons. Both AD and SCI-induced neuropathic pain are associated with spinal sprouting of peptidergic nociceptors that might increase synaptic input to the circuits involved in AD and SCI pain. In addition, numerous nociceptors become hyperexcitable, hypersensitive to chemicals associated with injury and inflammation, and spontaneously active, greatly amplifying sensory input to sensitized spinal circuits. As discussed with the aid of a preliminary functional model, these effects are likely to have mutually reinforcing relationships with each other, and with consequences of SCI-induced interruption of descending excitatory and inhibitory influences on spinal circuits, with SCI-induced inflammation in the spinal cord and in DRGs, and with activity in sympathetic fibers within DRGs that promotes local inflammation and spontaneous activity in sensory neurons. This model suggests that interventions selectively targeting hyperactivity in C-nociceptors might be useful for treating chronic pain and AD after high SCI.
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Affiliation(s)
- Edgar T Walters
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA.
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Fadda A, Bärtschi M, Hemphill A, Widmer HR, Zurbriggen A, Perona P, Vidondo B, Oevermann A. Primary Postnatal Dorsal Root Ganglion Culture from Conventionally Slaughtered Calves. PLoS One 2016; 11:e0168228. [PMID: 27936156 PMCID: PMC5148591 DOI: 10.1371/journal.pone.0168228] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 11/28/2016] [Indexed: 12/13/2022] Open
Abstract
Neurological disorders in ruminants have an important impact on veterinary health, but very few host-specific in vitro models have been established to study diseases affecting the nervous system. Here we describe a primary neuronal dorsal root ganglia (DRG) culture derived from calves after being conventionally slaughtered for food consumption. The study focuses on the in vitro characterization of bovine DRG cell populations by immunofluorescence analysis. The effects of various growth factors on neuron viability, neurite outgrowth and arborisation were evaluated by morphological analysis. Bovine DRG neurons are able to survive for more than 4 weeks in culture. GF supplementation is not required for neuronal survival and neurite outgrowth. However, exogenously added growth factors promote neurite outgrowth. DRG cultures from regularly slaughtered calves represent a promising and sustainable host specific model for the investigation of pain and neurological diseases in bovines.
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Affiliation(s)
- A. Fadda
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, Theodor Kocher Institute, University of Bern, Switzerland
| | - M. Bärtschi
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - A. Hemphill
- Institute for Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - H. R. Widmer
- Neurocenter and Regenerative Neuroscience Cluster, University Hospital and University of Bern, Bern, Switzerland
| | - A. Zurbriggen
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - P. Perona
- School of Engineering, The University of Edinburgh, Edinburgh, United Kingdom
| | - B. Vidondo
- Veterinary Public Health Institute (VPHI), Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - A. Oevermann
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- * E-mail:
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Wang F, Xiang H, Fischer G, Liu Z, Dupont MJ, Hogan QH, Yu H. HMG-CoA synthase isoenzymes 1 and 2 localize to satellite glial cells in dorsal root ganglia and are differentially regulated by peripheral nerve injury. Brain Res 2016; 1652:62-70. [PMID: 27671501 DOI: 10.1016/j.brainres.2016.09.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 09/19/2016] [Accepted: 09/22/2016] [Indexed: 12/19/2022]
Abstract
In dorsal root ganglia (DRG), satellite glial cells (SGCs) tightly ensheathe the somata of primary sensory neurons to form functional sensory units. SGCs are identified by their flattened and irregular morphology and expression of a variety of specific marker proteins. In this report, we present evidence that the 3-hydroxy-3-methylglutaryl coenzyme A synthase isoenzymes 1 and 2 (HMGCS1 and HMGCS2) are abundantly expressed in SGCs. Immunolabeling with the validated antibodies revealed that both HMGCS1 and HMGCS2 are highly colabeled with a selection of SGC markers, including GS, GFAP, Kir4.1, GLAST1, GDNF, and S100 but not with microglial cell marker Iba1, myelin sheath marker MBP, and neuronal marker β3-tubulin or phosphorylated CaMKII. HMGCS1 but not HMGCS2 immunoreactivity in SGCs is reduced in the fifth lumbar (L5) DRGs that contain axotomized neurons following L5 spinal nerve ligation (SNL) in rats. Western blot showed that HMGCS1 protein level in axotomized L5 DRGs is reduced after SNL to 66±8% at 3 days (p<0.01, n=4 animals in each group) and 58±13% at 28 days (p<0.001, n=9 animals in each group) of its level in control samples, whereas HMGCS2 protein was comparable between injured and control DRGs. These results identify HMGCSs as the alternative markers for SGCs in DRGs. Downregulated HMGCS1 expression in DRGs after spinal nerve injury may reflect a potential role of abnormal sterol metabolism of SGCs in the nerve injured-induced neuropathic pain.
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Affiliation(s)
- Fei Wang
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Medical Experiment Center, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi 712046, PR China
| | - Hongfei Xiang
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Orthopedic Surgery, Affiliated Hospitals of Qingdao University, Qingdao 266000, PR China
| | - Gregory Fischer
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Zhen Liu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Matthew J Dupont
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Quinn H Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295, USA
| | - Hongwei Yu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295, USA.
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131
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Coupled Activation of Primary Sensory Neurons Contributes to Chronic Pain. Neuron 2016; 91:1085-1096. [PMID: 27568517 DOI: 10.1016/j.neuron.2016.07.044] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 06/21/2016] [Accepted: 07/19/2016] [Indexed: 11/20/2022]
Abstract
Primary sensory neurons in the DRG play an essential role in initiating pain by detecting painful stimuli in the periphery. Tissue injury can sensitize DRG neurons, causing heightened pain sensitivity, often leading to chronic pain. Despite the functional importance, how DRG neurons function at a population level is unclear due to the lack of suitable tools. Here we developed an imaging technique that allowed us to simultaneously monitor the activities of >1,600 neurons/DRG in live mice and discovered a striking neuronal coupling phenomenon that adjacent neurons tend to activate together following tissue injury. This coupled activation occurs among various neurons and is mediated by an injury-induced upregulation of gap junctions in glial cells surrounding DRG neurons. Blocking gap junctions attenuated neuronal coupling and mechanical hyperalgesia. Therefore, neuronal coupling represents a new form of neuronal plasticity in the DRG and contributes to pain hypersensitivity by "hijacking" neighboring neurons through gap junctions.
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Affiliation(s)
- Parisa Gazerani
- Department of Health Science & Technology, Faculty of Medicine, Aalborg University, Frederik Bajers Vej 7A2-A2-208, 9220 Aalborg East, Denmark
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Gu Y, Wang C, Li G, Huang LYM. EXPRESS: F-actin links Epac-PKC signaling to purinergic P2X3 receptors sensitization in dorsal root ganglia following inflammation. Mol Pain 2016; 12:12/0/1744806916660557. [PMID: 27385722 PMCID: PMC4955968 DOI: 10.1177/1744806916660557] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Sensitization of purinergic P2X3 receptors (P2X3Rs) contributes to the production of exaggerated nociceptive responses following inflammatory injury. We showed previously that prostaglandin E2 (PGE2) potentiates P2X3R-mediated ATP currents in dorsal root ganglion neurons isolated from both control and complete Freund’s adjuvant-induced inflamed rats. PGE2 potentiation of ATP currents depends only on PKA signaling in control neurons, but it depends on both PKA and PKC signaling in inflamed neurons. We further found that inflammation evokes an increase in exchange proteins directly activated by cAMP (Epacs) in dorsal root ganglions. This increase promotes the activation of PKC to produce a much enhanced PGE2 effect on ATP currents and to elicit Epac-dependent flinch nocifensive behavioral responses in complete Freund’s adjuvant rats. The link between Epac-PKC signaling and P2X3R sensitization remains unexplored. Here, we show that the activation of Epacs promotes the expression of phosphorylated PKC and leads to an increase in the cytoskeleton, F-actin, expression at the cell perimeter. Depolymerization of F-actin blocks PGE2-enhanced ATP currents and inhibits P2X3R-mediated nocifensive responses after inflammation. Thus, F-actin is dynamically involved in the Epac-PKC-dependent P2X3R sensitization. Furthermore, Epacs induce a PKC-dependent increase in the membrane expression of P2X3Rs. This increase is abolished by F-actin depolymerization, suggesting that F-actin mediates Epac-PKC signaling of P2X3R membrane expression. Thus, after inflammation, an Epac-PKC dependent increase in F-actin in dorsal root ganglion neurons enhances the membrane expression of P2X3Rs to bring about sensitization of P2X3Rs and abnormal pain behaviors.
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Affiliation(s)
- Yanping Gu
- University of Texas Medical Branch at Galveston
| | - Congying Wang
- University of Texas Medical Branch at GalvestonUniversity of Texas Medical Branch at Galveston
| | - Guangwen Li
- University of Texas Medical Branch at Galveston
| | - Li-Yen Mae Huang
- University of Texas Medical Branch at GalvestonUniversity of Texas Medical Branch at Galveston
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Ciglieri E, Ferrini F, Boggio E, Salio C. An improved method for in vitro morphofunctional analysis of mouse dorsal root ganglia. Ann Anat 2016; 207:62-7. [PMID: 27224901 DOI: 10.1016/j.aanat.2016.04.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 03/17/2016] [Accepted: 04/21/2016] [Indexed: 12/11/2022]
Abstract
Sensory neurons in dorsal root ganglia (DRGs) are the first-order neurons along the pathway conveying sensory information from the periphery to the central nervous system. The analysis of the morphological and physiological features of these neurons and their alterations in pathology is the necessary prerequisite to understand pain encoding mechanisms. Here, we describe an in vitro procedure for combined morphofunctional analysis of mouse DRGs. Freshly excised DRGs obtained from adult mice were incubated in collagenase to dissolve the ensheathing connective capsule. The degradation of the connective tissue facilitates both access to the neurons by classical recording glass pipettes and the penetration of primary antibodies for immunohistochemical procedures. The entire DRGs were then imaged using a confocal microscope obtaining a fine 3D representation of their cytoarchitecture without requiring tissue sectioning. Thus, our proposed whole-mount preparation represents a flexible in vitro approach for both functional and phenotypic analysis of DRG neurons by at the same time preserving their neuroanatomical relationships.
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Affiliation(s)
- E Ciglieri
- Department of Veterinary Sciences, University of Turin, Largo Braccini 2, 10095 Grugliasco, TO, Italy
| | - F Ferrini
- Department of Veterinary Sciences, University of Turin, Largo Braccini 2, 10095 Grugliasco, TO, Italy
| | - E Boggio
- Department of Veterinary Sciences, University of Turin, Largo Braccini 2, 10095 Grugliasco, TO, Italy
| | - C Salio
- Department of Veterinary Sciences, University of Turin, Largo Braccini 2, 10095 Grugliasco, TO, Italy.
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135
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Chen Y, Zhang Y, Huo Y, Wang D, Hong Y. Adrenomedullin mediates tumor necrosis factor-α-induced responses in dorsal root ganglia in rats. Brain Res 2016; 1644:183-91. [PMID: 27184601 DOI: 10.1016/j.brainres.2016.05.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/30/2016] [Accepted: 05/11/2016] [Indexed: 01/08/2023]
Abstract
Adrenomedullin (AM), a member of the calcitonin gene-related peptide (CGRP) family, has been demonstrated to be a pain peptide. This study investigated the possible involvement of AM in tumor necrosis factor-alpha (TNF-α)-induced responses contributing to neuronal plasticity in the dorsal root ganglia (DRG). Exposure of the DRG explant cultures to TNF-α (5nM) for 48h upregulated the expression of AM mRNA. The treatment with TNF-α also increased the level of CGRP, CCL-2 and MMP-9 mRNA in the cultured DRG. This increase was attenuated by the co-treatment with the selective AM receptor antagonist AM22-52 (2μM). The blockade of AM receptors inhibited TNF-α-induced increase of the glial fibrillary acidic protein (GFAP), interleukin-1β (IL-1β), phosphorylated cAMP response element binding protein (pCREB) and nuclear factor kappa B (pNF-κB) proteins. On the other hand, the treatment with the AM receptor agonist AM1-50 (10nM) for 96h induced an increase in the level of GFAP, IL-1β, pCREB and pNF-κB proteins. The inhibition of AM activity did not change TNF-α-induced phosphorylation of extracellular signal-related kinase (pERK) while the treatment with AM1-50 still increased the level of pERK in the cultured DRG. Immunofluorescence assay showed the colocalization of AM-like immunoreactivity (IR) with TNF-α-IR in DRG neurons. The present study suggests that the increased AM receptor signaling mediated the many, but not all, TNF-α-induced activities, contributing to peripheral sensitization in neuropathic pain.
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Affiliation(s)
- Yajuan Chen
- College of Life Sciences and Provincial Key Laboratory of Developmental Biology and Neuroscience, Fujian Normal University Fuzhou, Fujian 350117, China
| | - Yan Zhang
- College of Life Sciences and Provincial Key Laboratory of Developmental Biology and Neuroscience, Fujian Normal University Fuzhou, Fujian 350117, China
| | - Yuanhui Huo
- College of Life Sciences and Provincial Key Laboratory of Developmental Biology and Neuroscience, Fujian Normal University Fuzhou, Fujian 350117, China
| | - Dongmei Wang
- College of Life Sciences and Provincial Key Laboratory of Developmental Biology and Neuroscience, Fujian Normal University Fuzhou, Fujian 350117, China
| | - Yanguo Hong
- College of Life Sciences and Provincial Key Laboratory of Developmental Biology and Neuroscience, Fujian Normal University Fuzhou, Fujian 350117, China.
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Liu S, Zou L, Xie J, Xie W, Wen S, Xie Q, Gao Y, Li G, Zhang C, Xu C, Xu H, Wu B, Lv Q, Zhang X, Wang S, Xue Y, Liang S. LncRNA NONRATT021972 siRNA regulates neuropathic pain behaviors in type 2 diabetic rats through the P2X7 receptor in dorsal root ganglia. Mol Brain 2016; 9:44. [PMID: 27107575 PMCID: PMC4841959 DOI: 10.1186/s13041-016-0226-2] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/15/2016] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Long non-protein-coding RNAs (lncRNAs) are involved in the pathological processes of nervous system diseases. NONRATT021972 is an lncRNA. This study explores the effects of lncRNA NONRATT021972 small interference RNA (siRNA) on diabetic neuropathic pain (DNP) mediated by the P2X7 receptor in the rat dorsal root ganglia (DRG). RESULTS Our results show that NONRATT021972 expression was significantly higher in the DRG of diabetes mellitus (DM) group compared with control group. NONRATT021972 expression in the DRG was reduced when DM rats were treated with NONRATT021972 siRNA. NONRATT021972 siRNA treatment in type 2 DM rats increased the mechanical withdrawal threshold (MWT), the thermal withdrawal latency (TWL) and the sensory nerve conduction velocity (SNCV) of rat tail nerves. After intravenous injection with NONRATT021972 siRNA in DM rats, the P2X7, GFAP and TNF-ɑ expression levels in DRG were decreased. An interaction between the RNA (NONRATT021972) and protein (P2X7) was predicted by the application of bioinformatics technology. The BzATP-activated currents in DRG non-neurons (satellite glial cells) of DM rats were significantly increased compared to control rats. NONRATT021972 siRNA treatment inhibited the ATP-activated currents in HEK293 cells transfected with pEGFP-P2X7. CONCLUSIONS NONRATT021972 siRNA treatment can decrease the expression levels of P2X7 mRNA and protein and inhibit the activation of satellite glial cells (SGCs) in the DRG of type 2 DM rats. Moreover, NONRATT021972 siRNA treatment reduced the release of inflammatory factors (TNF-α), thereby inhibiting the excitability of DRG neurons and reducing mechanical and thermal hyperalgesia in type 2 DM rats.
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Affiliation(s)
- Shuangmei Liu
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Lifang Zou
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Jinyan Xie
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Wei Xie
- Clinic Medicine Department, Undergraduate Student of Grade 2012, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Shiyao Wen
- Clinic Medicine Department, Undergraduate Student of Grade 2012, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Qiuyu Xie
- Clinic Medicine Department, Undergraduate Student of Grade 2012, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Yun Gao
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Guilin Li
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Chunping Zhang
- Department of Cell Biology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Changshui Xu
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Hong Xu
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Bing Wu
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Qiulan Lv
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Xi Zhang
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Shouyu Wang
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Yun Xue
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Shangdong Liang
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China.
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Abstract
Glia account for more than half of the cells in the mammalian nervous system, and the past few decades have witnessed a flood of studies that detail novel functions for glia in nervous system development, plasticity and disease. Here, and in the accompanying poster, we review the origins of glia and discuss their diverse roles during development, in the adult nervous system and in the context of disease.
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Affiliation(s)
- J Bradley Zuchero
- Department of Neurobiology, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Ben A Barres
- Department of Neurobiology, Stanford University, School of Medicine, Stanford, CA 94305, USA
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138
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Warwick RA, Hanani M. Involvement of aberrant calcium signalling in herpetic neuralgia. Exp Neurol 2015; 277:10-18. [PMID: 26684187 DOI: 10.1016/j.expneurol.2015.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 12/03/2015] [Accepted: 12/08/2015] [Indexed: 11/18/2022]
Abstract
Alpha-herpesviruses, herpes simplex viruses (HSV) and varicella zoster virus (VZV), are pathogens of the peripheral nervous system. After primary infection, these viruses establish latency within sensory ganglia, while retaining the ability to reactivate. Reactivation of VZV results in herpes zoster, a condition characterized by skin lesions that leads to post-herpetic neuralgia. Recurrent reactivations of HSV, which cause mucocutaneous lesions, may also result in neuralgia. During reactivation of alpha-herpesviruses, satellite glial cells (SGCs), which surround neurons in sensory ganglia, become infected with the replicating virus. SGCs are known to contribute to neuropathic pain in a variety of animal pain models. Here we investigated how infection of short-term cultures of mouse trigeminal ganglia with HSV-1 affects communication between SGCs and neurons, and how this altered communication may increase neuronal excitability, thus contributing to herpetic neuralgia. Mechanical stimulation of single neurons or SGCs resulted in intercellular calcium waves, which were larger in cultures infected with HSV-1. Two differences were observed between control and HSV-1 infected cultures that could account for this augmentation. Firstly, HSV-1 infection induced cell fusion among SGCs and neurons, which would facilitate the spread of calcium signals over farther distances. Secondly, using calcium imaging and intracellular electrical recordings, we found that neurons in the HSV-1 infected cultures exhibited augmented influx of calcium upon depolarization. These virally induced changes may not only cause more neurons in the sensory ganglia to fire action potentials, but may also increase neurotransmitter release at the presynaptic terminals in the spinal cord. They are therefore likely to be contributing factors to herpetic neuralgia.
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Affiliation(s)
- Rebekah A Warwick
- Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem 91240, Israel.
| | - Menachem Hanani
- Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem 91240, Israel
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139
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Chen Y, Li G, Huang LYM. p38 MAPK mediates glial P2X7R-neuronal P2Y1R inhibitory control of P2X3R expression in dorsal root ganglion neurons. Mol Pain 2015; 11:68. [PMID: 26542462 PMCID: PMC4635984 DOI: 10.1186/s12990-015-0073-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 10/27/2015] [Indexed: 12/20/2022] Open
Abstract
Background We have previously shown that endogenously active purinergic P2X7 receptors (P2X7Rs) in satellite glial cells of dorsal root ganglia (DRGs) stimulate ATP release. The ATP activates P2Y1Rs located in the enwrapped neuronal somata, resulting in down-regulation of P2X3Rs. This P2X7R-P2Y1-P2X3R inhibitory control significantly reduces P2X3R-mediated nociceptive responses. The underlying mechanism by which the activation of P2Y1Rs inhibits the expression of P2X3Rs remains unexplored. Results Examining the effect of the activation of p38 mitogen-activated protein kinase on the expression of P2X3Rs in DRGs, we found that the p38 activator, anisomycin (Anis), reduced the expression of P2X3Rs. Blocking the activity of SGCs by the glial Krebs cycle inhibitor, fluorocitrate, did not change the effect of Anis. These results suggest that neuronal p38 plays a major role in the inhibition of P2X3R expression. Western blotting analyses showed that inhibiting P2Y1Rs by MRS2179 (MRS) or blocking P2X7Rs by either oxATP or A740003 reduced pp38 and increased P2X3R expression in DRGs. These results are further supported by the immunohistochemical study showing that P2X7R and P2Y1R antagonists reduce the percentage of pp38-positive neurons. These observations suggest that activation of P2X7Rs and P2Y1Rs promotes p38 activity to exert inhibitory control on P2X3R expression. Since activation of p38 by Anis in the presence of either A740003 or MRS could overcome the block of P2X7R-P2Y1R inhibitory control, p38 in DRG neurons is downstream of P2Y1Rs. In addition, inhibition of p38 by SB202190 was found to prevent the P2X7R and P2Y1R block of P2X3R expression and increase P2X3R-mediated nociceptive flinch behaviors. Conclusions p38 in DRG neurons downstream of P2Y1R is necessary and sufficient for the P2X7R-P2Y1R inhibitory control of P2X3R expression.
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Affiliation(s)
- Yong Chen
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555-1069, USA.
| | - Guangwen Li
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555-1069, USA.
| | - Li-Yen Mae Huang
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555-1069, USA.
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140
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Current status and future directions of botulinum neurotoxins for targeting pain processing. Toxins (Basel) 2015; 7:4519-63. [PMID: 26556371 PMCID: PMC4663519 DOI: 10.3390/toxins7114519] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/29/2015] [Accepted: 10/19/2015] [Indexed: 12/20/2022] Open
Abstract
Current evidence suggests that botulinum neurotoxins (BoNTs) A1 and B1, given locally into peripheral tissues such as skin, muscles, and joints, alter nociceptive processing otherwise initiated by inflammation or nerve injury in animal models and humans. Recent data indicate that such locally delivered BoNTs exert not only local action on sensory afferent terminals but undergo transport to central afferent cell bodies (dorsal root ganglia) and spinal dorsal horn terminals, where they cleave SNAREs and block transmitter release. Increasing evidence supports the possibility of a trans-synaptic movement to alter postsynaptic function in neuronal and possibly non-neuronal (glial) cells. The vast majority of these studies have been conducted on BoNT/A1 and BoNT/B1, the only two pharmaceutically developed variants. However, now over 40 different subtypes of botulinum neurotoxins (BoNTs) have been identified. By combining our existing and rapidly growing understanding of BoNT/A1 and /B1 in altering nociceptive processing with explorations of the specific characteristics of the various toxins from this family, we may be able to discover or design novel, effective, and long-lasting pain therapeutics. This review will focus on our current understanding of the molecular mechanisms whereby BoNTs alter pain processing, and future directions in the development of these agents as pain therapeutics.
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141
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Hanani M. Role of satellite glial cells in gastrointestinal pain. Front Cell Neurosci 2015; 9:412. [PMID: 26528140 PMCID: PMC4602093 DOI: 10.3389/fncel.2015.00412] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 09/28/2015] [Indexed: 12/12/2022] Open
Abstract
Gastrointestinal (GI) pain is a common clinical problem, for which effective therapy is quite limited. Sensations from the GI tract, including pain, are mediated largely by neurons in the dorsal root ganglia (DRG), and to a smaller extent by vagal afferents emerging from neurons in the nodose/jugular ganglia. Neurons in rodent DRG become hyperexcitable in models of GI pain (e.g., gastric or colonic inflammation), and can serve as a source for chronic pain. Glial cells are another element in the pain signaling pathways, and there is evidence that spinal glial cells (microglia and astrocytes) undergo activation (gliosis) in various pain models and contribute to pain. Recently it was found that satellite glial cells (SGCs), the main type of glial cells in sensory ganglia, might also contribute to chronic pain in rodent models. Most of that work focused on somatic pain, but in several studies GI pain was also investigated, and these are discussed in the present review. We have shown that colonic inflammation induced by dinitrobenzene sulfonic acid (DNBS) in mice leads to the activation of SGCs in DRG and increases gap junction-mediated coupling among these cells. This coupling appears to contribute to the hyperexcitability of DRG neurons that innervate the colon. Blocking gap junctions (GJ) in vitro reduced neuronal hyperexcitability induced by inflammation, suggesting that glial GJ participate in SGC-neuron interactions. Moreover, blocking GJ by carbenoxolone and other agents reduces pain behavior. Similar changes in SGCs were also found in the mouse nodose ganglia (NG), which provide sensory innervation to most of the GI tract. Following systemic inflammation, SGCs in these ganglia were activated, and displayed augmented coupling and greater sensitivity to the pain mediator ATP. The contribution of these changes to visceral pain remains to be determined. These results indicate that although visceral pain is unique, it shares basic mechanisms with somatic pain, suggesting that therapeutic approaches to both pain types may be similar. Future research in this field should include additional types of GI injury and also other types of visceral pain.
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Affiliation(s)
- Menachem Hanani
- Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus Jerusalem, Israel
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142
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Galbavy W, Kaczocha M, Puopolo M, Liu L, Rebecchi MJ. Neuroimmune and Neuropathic Responses of Spinal Cord and Dorsal Root Ganglia in Middle Age. PLoS One 2015; 10:e0134394. [PMID: 26241743 PMCID: PMC4524632 DOI: 10.1371/journal.pone.0134394] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 07/08/2015] [Indexed: 02/07/2023] Open
Abstract
Prior studies of aging and neuropathic injury have focused on senescent animals compared to young adults, while changes in middle age, particularly in the dorsal root ganglia (DRG), have remained largely unexplored. 14 neuroimmune mRNA markers, previously associated with peripheral nerve injury, were measured in multiplex assays of lumbar spinal cord (LSC), and DRG from young and middle-aged (3, 17 month) naïve rats, or from rats subjected to chronic constriction injury (CCI) of the sciatic nerve (after 7 days), or from aged-matched sham controls. Results showed that CD2, CD3e, CD68, CD45, TNF-α, IL6, CCL2, ATF3 and TGFβ1 mRNA levels were substantially elevated in LSC from naïve middle-aged animals compared to young adults. Similarly, LSC samples from older sham animals showed increased levels of T-cell and microglial/macrophage markers. CCI induced further increases in CCL2, and IL6, and elevated ATF3 mRNA levels in LSC of young and middle-aged adults. Immunofluorescence images of dorsal horn microglia from middle-aged naïve or sham rats were typically hypertrophic with mostly thickened, de-ramified processes, similar to microglia following CCI. Unlike the spinal cord, marker expression profiles in naïve DRG were unchanged across age (except increased ATF3); whereas, levels of GFAP protein, localized to satellite glia, were highly elevated in middle age, but independent of nerve injury. Most neuroimmune markers were elevated in DRG following CCI in young adults, yet middle-aged animals showed little response to injury. No age-related changes in nociception (heat, cold, mechanical) were observed in naïve adults, or at days 3 or 7 post-CCI. The patterns of marker expression and microglial morphologies in healthy middle age are consistent with development of a para-inflammatory state involving microglial activation and T-cell marker elevation in the dorsal horn, and neuronal stress and satellite cell activation in the DRG. These changes, however, did not affect the establishment of neuropathic pain.
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Affiliation(s)
- William Galbavy
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Martin Kaczocha
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Michelino Puopolo
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Lixin Liu
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Mario J Rebecchi
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
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143
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Feldman-Goriachnik R, Belzer V, Hanani M. Systemic inflammation activates satellite glial cells in the mouse nodose ganglion and alters their functions. Glia 2015; 63:2121-2132. [DOI: 10.1002/glia.22881] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 06/08/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Rachel Feldman-Goriachnik
- Laboratory of Experimental Surgery; Hadassah-Hebrew University Medical Center; Mount Scopus Jerusalem 91240 Israel
| | - Vitali Belzer
- Laboratory of Experimental Surgery; Hadassah-Hebrew University Medical Center; Mount Scopus Jerusalem 91240 Israel
| | - Menachem Hanani
- Laboratory of Experimental Surgery; Hadassah-Hebrew University Medical Center; Mount Scopus Jerusalem 91240 Israel
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144
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Poulsen JN, Warwick R, Duroux M, Hanani M, Gazerani P. Oxaliplatin enhances gap junction-mediated coupling in cell cultures of mouse trigeminal ganglia. Exp Cell Res 2015; 336:94-9. [PMID: 25999145 DOI: 10.1016/j.yexcr.2015.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 05/06/2015] [Accepted: 05/08/2015] [Indexed: 12/13/2022]
Abstract
Communications between satellite glial cells and neighboring neurons within sensory ganglia may contribute to neuropathic and inflammatory pain. To elucidate the role of satellite glial cells in chemotherapy-induced pain, we examined the effects of oxaliplatin on the gap junction-mediated coupling between these cells. We also examined whether the gap junction blocker, carbenoxolone, can reverse the coupling. Primary cultures of mice trigeminal ganglia, 24-48h after cell isolation, were used. Satellite glial cells were injected with Lucifer yellow in the presence or absence of oxaliplatin (60 μM). In addition, the effect of carbenoxolone (100 μM) on coupling, and the expression of connexin 43 proteins were evaluated. Dye coupling between adjacent satellite glial cells was significantly increased (2.3-fold, P<0.05) following a 2h incubation with oxaliplatin. Adding carbenoxolone to the oxaliplatin-treated cultures reversed oxaliplatin-evoked coupling to baseline (P<0.05). Immunostaining showed no difference between expression of connexin 43 in control and oxaliplatin-treated cultures. Our findings indicated that oxaliplatin-increased gap junction-mediated coupling between satellite glial cells in primary cultures of mouse trigeminal ganglia, and carbenoxolone reversed this effect. Hence, it is proposed that increased gap junction-mediated coupling was seen between satellite glial cells in TG. This observation together with our previous data obtained from a behavioral study suggests that this phenomenon might contribute to chemotherapy-induced nociception following oxaliplatin treatment.
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Affiliation(s)
- Jeppe Nørgaard Poulsen
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Fredrik Bajers Vej 7D3, Aalborg East DK-9220, Denmark
| | - Rebekah Warwick
- Laboratory of Experimental Surgery, Hadassah University Hospital, Mount Scopus, Jerusalem, Israel
| | - Meg Duroux
- Laboratory for Cancer Biology, Biomedicine, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Fredrik Bajers Vej 3B, Aalborg East DK-9220, Denmark
| | - Menachem Hanani
- Laboratory of Experimental Surgery, Hadassah University Hospital, Mount Scopus, Jerusalem, Israel
| | - Parisa Gazerani
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Fredrik Bajers Vej 7D3, Aalborg East DK-9220, Denmark; Laboratory for Cancer Biology, Biomedicine, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Fredrik Bajers Vej 3B, Aalborg East DK-9220, Denmark.
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145
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Zhang Y, Laumet G, Chen SR, Hittelman WN, Pan HL. Pannexin-1 Up-regulation in the Dorsal Root Ganglion Contributes to Neuropathic Pain Development. J Biol Chem 2015; 290:14647-55. [PMID: 25925949 DOI: 10.1074/jbc.m115.650218] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Indexed: 01/10/2023] Open
Abstract
Pannexin-1 (Panx1) is a large-pore membrane channel involved in the release of ATP and other signaling mediators. Little is known about the expression and functional role of Panx1 in the dorsal root ganglion (DRG) in the development of chronic neuropathic pain. In this study, we determined the epigenetic mechanism involved in increased Panx1 expression in the DRG after nerve injury. Spinal nerve ligation in rats significantly increased the mRNA and protein levels of Panx1 in the DRG but not in the spinal cord. Immunocytochemical labeling showed that Panx1 was primarily expressed in a subset of medium and large DRG neurons in control rats and that nerve injury markedly increased the number of Panx1-immunoreactive DRG neurons. Nerve injury significantly increased the enrichment of two activating histone marks (H3K4me2 and H3K9ac) and decreased the occupancy of two repressive histone marks (H3K9me2 and H3K27me3) around the promoter region of Panx1 in the DRG. However, nerve injury had no effect on the DNA methylation level around the Panx1 promoter in the DRG. Furthermore, intrathecal injection of the Panx1 blockers or Panx1-specific siRNA significantly reduced pain hypersensitivity induced by nerve injury. In addition, siRNA knockdown of Panx1 expression in a DRG cell line significantly reduced caspase-1 release induced by neuronal depolarization. Our findings suggest that nerve injury increases Panx1 expression levels in the DRG through altered histone modifications. Panx1 up-regulation contributes to the development of neuropathic pain and stimulation of inflammasome signaling.
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Affiliation(s)
- Yuhao Zhang
- From the Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine and
| | - Geoffroy Laumet
- From the Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine and
| | - Shao-Rui Chen
- From the Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine and
| | - Walter N Hittelman
- Department of Experimental Therapeutics, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
| | - Hui-Lin Pan
- From the Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine and
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146
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Magni G, Merli D, Verderio C, Abbracchio MP, Ceruti S. P2Y2 receptor antagonists as anti-allodynic agents in acute and sub-chronic trigeminal sensitization: role of satellite glial cells. Glia 2015; 63:1256-69. [PMID: 25779655 DOI: 10.1002/glia.22819] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 01/28/2015] [Accepted: 02/27/2015] [Indexed: 12/18/2022]
Abstract
Trigeminal (TG) pain often lacks a satisfactory pharmacological control. A better understanding of the molecular cross-talk between TG neurons and surrounding satellite glial cells (SGCs) could help identifying innovative targets for the development of more effective analgesics. We have previously demonstrated that neuronal pro-algogenic mediators upregulate G protein-coupled nucleotide P2Y receptors (P2YRs) expressed by TG SGCs in vitro. Here, we have identified the specific P2YR subtypes involved (i.e., the ADP-sensitive P2Y1 R and the UTP-responsive P2Y2 R subtypes), and demonstrated the contribution of neuron-derived prostaglandins to their upregulation. Next, we have translated these data to an in vivo model of TG pain (namely, rats injected with Complete Freund's adjuvant in the temporomandibular joint), by demonstrating activation of SGCs and upregulation of P2Y1 R and P2Y2 R in the ipsi-lateral TG. To unequivocally link P2YRs to the development of facial allodynia, we treated animals with various purinergic antagonists. The selective P2Y2 R antagonist AR-C118925 completely inhibited SGCs activation, exerted a potent anti-allodynic effect that lasted over time, and was still effective when administration was started 6-days post induction of allodynia, i.e. under subchronic pain conditions. Conversely, the selective P2Y1 R antagonist MRS2179 was completely ineffective. Moreover, similarly to the anti-inflammatory drug acetylsalicylic acid and the known anti-migraine agent sumatriptan, the P2X/P2Y nonselective antagonist PPADS was only partially effective, and completely lost its activity under sub-chronic conditions. Taken together, our results highlight glial P2Y2 Rs as potential "druggable" targets for the successful management of TG-related pain.
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Affiliation(s)
- Giulia Magni
- Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological and Biomolecular Sciences, Università Degli Studi Di Milano, via Balzaretti, 9, Milan, Italy; Department of Drug Discovery and Development, Italian Institute of Technology (IIT), via Morego, 30, Genoa, Italy
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147
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Hanani M, Blum E, Liu S, Peng L, Liang S. Satellite glial cells in dorsal root ganglia are activated in streptozotocin-treated rodents. J Cell Mol Med 2014; 18:2367-71. [PMID: 25312986 PMCID: PMC4302642 DOI: 10.1111/jcmm.12406] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Accepted: 07/18/2014] [Indexed: 12/19/2022] Open
Abstract
Neuropathic pain is a very common complication in diabetes mellitus (DM), and treatment for it is limited. As DM is becoming a global epidemic it is important to understand and treat this problem. The mechanisms of diabetic neuropathic pain are largely obscure. Recent studies have shown that glial cells are important for a variety of neuropathic pain types, and we investigated what are the changes that satellite glial cells (SGCs) in dorsal root ganglia undergo in a DM type 1 model, induced by streptozotocin (STZ) in mice and rats. We carried out immunohistochemical studies to learn about changes in the activation marker glial fibrillary acidic protein (GFAP) in SGCs. We found that after STZ-treatment the number of neurons surrounded with GFAP-positive SGCs in dorsal root ganglia increased 4-fold in mice and 5-fold in rats. Western blotting for GFAP, which was done only on rats because of the larger size of the ganglia, showed an increase of about 2-fold in STZ-treated rats, supporting the immunohistochemical results. These results indicate for the first time that SGCs are activated in rodent models of DM1. As SGC activation appears to contribute to chronic pain, these results suggest that SGCs may participate in the generation and maintenance of diabetic neuropathic pain, and can serve as a potential therapeutic target.
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Affiliation(s)
- Menachem Hanani
- Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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148
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Walters ET. Neuroinflammatory contributions to pain after SCI: roles for central glial mechanisms and nociceptor-mediated host defense. Exp Neurol 2014; 258:48-61. [PMID: 25017887 DOI: 10.1016/j.expneurol.2014.02.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/23/2014] [Accepted: 02/02/2014] [Indexed: 12/30/2022]
Abstract
Neuropathic pain after spinal cord injury (SCI) is common, often intractable, and can be severely debilitating. A number of mechanisms have been proposed for this pain, which are discussed briefly, along with methods for revealing SCI pain in animal models, such as the recently applied conditioned place preference test. During the last decade, studies of animal models have shown that both central neuroinflammation and behavioral hypersensitivity (indirect reflex measures of pain) persist chronically after SCI. Interventions that reduce neuroinflammation have been found to ameliorate pain-related behavior, such as treatment with agents that inhibit the activation states of microglia and/or astroglia (including IL-10, minocycline, etanercept, propentofylline, ibudilast, licofelone, SP600125, carbenoxolone). Reversal of pain-related behavior has also been shown with disruption by an inhibitor (CR8) and/or genetic deletion of cell cycle-related proteins, deletion of a truncated receptor (trkB.T1) for brain-derived neurotrophic factor (BDNF), or reduction by antisense knockdown or an inhibitor (AMG9810) of the activity of channels (TRPV1 or Nav1.8) important for electrical activity in primary nociceptors. Nociceptor activity is known to drive central neuroinflammation in peripheral injury models, and nociceptors appear to be an integral component of host defense. Thus, emerging results suggest that spinal and systemic effects of SCI can activate nociceptor-mediated host defense responses that interact via neuroinflammatory signaling with complex central consequences of SCI to drive chronic pain. This broader view of SCI-induced neuroinflammation suggests new targets, and additional complications, for efforts to develop effective treatments for neuropathic SCI pain.
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Affiliation(s)
- Edgar T Walters
- Department of Integrative Biology and Pharmacology, University of Texas Medical School at Houston, TX, USA.
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149
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Wagner L, Warwick RA, Pannicke T, Reichenbach A, Grosche A, Hanani M. Glutamate release from satellite glial cells of the murine trigeminal ganglion. Neurosci Lett 2014; 578:143-7. [DOI: 10.1016/j.neulet.2014.06.047] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 06/19/2014] [Accepted: 06/21/2014] [Indexed: 10/25/2022]
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150
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Blum E, Procacci P, Conte V, Hanani M. Systemic inflammation alters satellite glial cell function and structure. A possible contribution to pain. Neuroscience 2014; 274:209-17. [PMID: 24875177 DOI: 10.1016/j.neuroscience.2014.05.029] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/15/2014] [Accepted: 05/16/2014] [Indexed: 12/30/2022]
Abstract
Local peripheral injury activates satellite glial cells (SGCs) in sensory ganglia, which may contribute to chronic pain. We hypothesized that systemic inflammation affects sensory ganglia like local injury. We induced systemic inflammation in mice by injecting lipopolysaccharide (LPS) intraperitoneally, and characterized SGCs and neurons in dorsal root ganglia (DRG), using dye injection, calcium imaging, electron microscopy (EM), immunohistochemistry, and electrical recordings. Several days post-LPS, SGCs were activated, and dye coupling among SGCs increased 3-4.5-fold. EM showed abnormal growth of SGC processes and the formation of new gap junctions. Sensitivity of SGCs to ATP increased twofold, and neuronal excitability was augmented. Blocking gap junctions reduced pain behavior in LPS-treated mice. Thus, changes in DRG due to systemic inflammation are similar to those due to local injury, which may explain the pain in sickness behavior and in other systemic diseases.
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Affiliation(s)
- E Blum
- Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem 91240, Israel
| | - P Procacci
- Dipartimento di Scienze Biomediche per la Salute, University of Milan, via Mangiagalli 14, I-20133 Milano, Italy
| | - V Conte
- Dipartimento di Scienze Biomediche per la Salute, University of Milan, via Mangiagalli 14, I-20133 Milano, Italy
| | - M Hanani
- Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem 91240, Israel.
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