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Beazley-Long N, Moss CE, Ashby WR, Bestall SM, Almahasneh F, Durrant AM, Benest AV, Blackley Z, Ballmer-Hofer K, Hirashima M, Hulse RP, Bates DO, Donaldson LF. VEGFR2 promotes central endothelial activation and the spread of pain in inflammatory arthritis. Brain Behav Immun 2018; 74:49-67. [PMID: 29548992 PMCID: PMC6302073 DOI: 10.1016/j.bbi.2018.03.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 03/02/2018] [Accepted: 03/11/2018] [Indexed: 02/01/2023] Open
Abstract
Chronic pain can develop in response to conditions such as inflammatory arthritis. The central mechanisms underlying the development and maintenance of chronic pain in humans are not well elucidated although there is evidence for a role of microglia and astrocytes. However in pre-clinical models of pain, including models of inflammatory arthritis, there is a wealth of evidence indicating roles for pathological glial reactivity within the CNS. In the spinal dorsal horn of rats with painful inflammatory arthritis we found both a significant increase in CD11b+ microglia-like cells and GFAP+ astrocytes associated with blood vessels, and the number of activated blood vessels expressing the adhesion molecule ICAM-1, indicating potential glio-vascular activation. Using pharmacological interventions targeting VEGFR2 in arthritic rats, to inhibit endothelial cell activation, the number of dorsal horn ICAM-1+ blood vessels, CD11b+ microglia and the development of secondary mechanical allodynia, an indicator of central sensitization, were all prevented. Targeting endothelial VEGFR2 by inducible Tie2-specific VEGFR2 knock-out also prevented secondary allodynia in mice and glio-vascular activation in the dorsal horn in response to inflammatory arthritis. Inhibition of VEGFR2 in vitro significantly blocked ICAM-1-dependent monocyte adhesion to brain microvascular endothelial cells, when stimulated with inflammatory mediators TNF-α and VEGF-A165a. Taken together our findings suggest that a novel VEGFR2-mediated spinal cord glio-vascular mechanism may promote peripheral CD11b+ circulating cell transmigration into the CNS parenchyma and contribute to the development of chronic pain in inflammatory arthritis. We hypothesise that preventing this glio-vascular activation and circulating cell translocation into the spinal cord could be a new therapeutic strategy for pain caused by rheumatoid arthritis.
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Affiliation(s)
- Nicholas Beazley-Long
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Catherine Elizabeth Moss
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham NG7 2UH, UK
| | - William Robert Ashby
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham NG7 2UH, UK
| | - Samuel Marcus Bestall
- Cancer Biology, School of Medicine, QMC, University of Nottingham, Nottingham NG7 2UH, UK
| | - Fatimah Almahasneh
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham NG7 2UH, UK
| | - Alexandra Margaret Durrant
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham NG7 2UH, UK
| | - Andrew Vaughan Benest
- Cancer Biology, School of Medicine, QMC, University of Nottingham, Nottingham NG7 2UH, UK
| | - Zoe Blackley
- Cancer Biology, School of Medicine, QMC, University of Nottingham, Nottingham NG7 2UH, UK
| | | | - Masanori Hirashima
- Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Japan
| | - Richard Phillip Hulse
- Cancer Biology, School of Medicine, QMC, University of Nottingham, Nottingham NG7 2UH, UK
| | - David Owen Bates
- Cancer Biology, School of Medicine, QMC, University of Nottingham, Nottingham NG7 2UH, UK,COMPARE University of Birmingham and University of Nottingham Midlands, UK
| | - Lucy Frances Donaldson
- Arthritis Research UK Pain Centre & School of Life Sciences, Medical School, University of Nottingham, Nottingham NG7 2UH, UK
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Hathway GJ, Murphy E, Lloyd J, Greenspon C, Hulse RP. Cancer Chemotherapy in Early Life Significantly Alters the Maturation of Pain Processing. Neuroscience 2018; 387:214-229. [PMID: 29196027 PMCID: PMC6150930 DOI: 10.1016/j.neuroscience.2017.11.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 10/24/2017] [Accepted: 11/16/2017] [Indexed: 12/22/2022]
Abstract
Advances in pediatric cancer treatment have led to a ten year survival rate greater than 75%. Platinum-based chemotherapies (e.g. cisplatin) induce peripheral sensory neuropathy in adult and pediatric cancer patients. The period from birth through to adulthood represents a period of maturation within nociceptive systems. Here we investigated how cisplatin impacts upon postnatal maturation of nociceptive systems. Neonatal Wistar rats (Postnatal day (P) 7) were injected (i.p.) daily with either vehicle (PBS) or cisplatin (1mg/kg) for five consecutive days. Neither group developed mechanical or thermal hypersensitivity immediately during or after treatment. At P22 the cisplatin group developed mechanical (P < 0.05) and thermal (P < 0.0001) hypersensitivity versus vehicle group. Total DRG or dorsal horn neuronal number did not differ at P45, however there was an increase in intraepidermal nerve fiber density in cisplatin-treated animals at this age. The percentage of IB4+ve, CGRP+ve and NF200+ve DRG neurons was not different between groups at P45. There was an increase in TrkA+ve DRG neurons in the cisplatin group at P45, in addition to increased TrkA, NF200 and vGLUT2 immunoreactivity in the lumbar dorsal horn versus controls. These data highlight the impact pediatric cancer chemotherapy has upon the maturation of pain pathways and later life pain experience.
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Affiliation(s)
- G J Hathway
- School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, United Kingdom.
| | - Emily Murphy
- Cancer Biology, School of Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom
| | - Joseph Lloyd
- School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, United Kingdom
| | - Charles Greenspon
- School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, United Kingdom
| | - R P Hulse
- Cancer Biology, School of Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom; School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, United Kingdom.
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Ved N, Da Vitoria Lobo ME, Bestall SM, L Vidueira C, Beazley-Long N, Ballmer-Hofer K, Hirashima M, Bates DO, Donaldson LF, Hulse RP. Diabetes-induced microvascular complications at the level of the spinal cord: a contributing factor in diabetic neuropathic pain. J Physiol 2018; 596:3675-3693. [PMID: 29774557 PMCID: PMC6092307 DOI: 10.1113/jp275067] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/08/2018] [Indexed: 02/06/2023] Open
Abstract
KEY POINTS Diabetes is thought to induce neuropathic pain through activation of dorsal horn sensory neurons in the spinal cord. Here we explore the impact of hyperglycaemia on the blood supply supporting the spinal cord and chronic pain development. In streptozotocin-induced diabetic rats, neuropathic pain is accompanied by a decline in microvascular integrity in the dorsal horn. Hyperglycaemia-induced degeneration of the endothelium in the dorsal horn was associated with a loss in vascular endothelial growth factor (VEGF)-A165 b expression. VEGF-A165 b treatment prevented diabetic neuropathic pain and degeneration of the endothelium in the spinal cord. Using an endothelial-specific VEGFR2 knockout transgenic mouse model, the loss of endothelial VEGFR2 signalling led to a decline in vascular integrity in the dorsal horn and the development of hyperalgesia in VEGFR2 knockout mice. This highlights that vascular degeneration in the spinal cord could be a previously unidentified factor in the development of diabetic neuropathic pain. ABSTRACT Abnormalities of neurovascular interactions within the CNS of diabetic patients is associated with the onset of many neurological disease states. However, to date, the link between the neurovascular network within the spinal cord and regulation of nociception has not been investigated despite neuropathic pain being common in diabetes. We hypothesised that hyperglycaemia-induced endothelial degeneration in the spinal cord, due to suppression of vascular endothelial growth factor (VEGF)-A/VEGFR2 signalling, induces diabetic neuropathic pain. Nociceptive pain behaviour was investigated in a chemically induced model of type 1 diabetes (streptozotocin induced, insulin supplemented; either vehicle or VEGF-A165 b treated) and an inducible endothelial knockdown of VEGFR2 (tamoxifen induced). Diabetic animals developed mechanical allodynia and heat hyperalgesia. This was associated with a reduction in the number of blood vessels and reduction in Evans blue extravasation in the lumbar spinal cord of diabetic animals versus age-matched controls. Endothelial markers occludin, CD31 and VE-cadherin were downregulated in the spinal cord of the diabetic group versus controls, and there was a concurrent reduction of VEGF-A165 b expression. In diabetic animals, VEGF-A165 b treatment (biweekly i.p., 20 ng g-1 ) restored normal Evans blue extravasation and prevented vascular degeneration, diabetes-induced central neuron activation and neuropathic pain. Inducible knockdown of VEGFR2 (tamoxifen treated Tie2CreERT2 -vegfr2flfl mice) led to a reduction in blood vessel network volume in the lumbar spinal cord and development of heat hyperalgesia. These findings indicate that hyperglycaemia leads to a reduction in the VEGF-A/VEGFR2 signalling cascade, resulting in endothelial dysfunction in the spinal cord, which could be an undiscovered contributing factor to diabetic neuropathic pain.
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Affiliation(s)
- N Ved
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK.,Institute of Ophthalmology, 11-43 Bath St, London, EC1V 9EL, UK.,Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - M E Da Vitoria Lobo
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK
| | - S M Bestall
- Arthritis Research UK Pain Centre and School of Life Sciences, The Medical School QMC, University of Nottingham, Nottingham, NG7 2UH, UK
| | - C L Vidueira
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK
| | - N Beazley-Long
- Arthritis Research UK Pain Centre and School of Life Sciences, The Medical School QMC, University of Nottingham, Nottingham, NG7 2UH, UK
| | | | - M Hirashima
- Division of Vascular Biology, Kobe University, Japan
| | - D O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK.,Centre of Membrane and Protein and Receptors (COMPARE), University of Birmingham, Birmingham and University of Nottingham, Nottingham, UK
| | - L F Donaldson
- Institute of Ophthalmology, 11-43 Bath St, London, EC1V 9EL, UK
| | - R P Hulse
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK.,School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS, UK
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Hulse RP, Beazley-Long N, Hua J, Kennedy H, Prager J, Bevan H, Qiu Y, Fernandes ES, Gammons MV, Ballmer-Hofer K, Gittenberger de Groot AC, Churchill AJ, Harper SJ, Brain SD, Bates DO, Donaldson LF. Regulation of alternative VEGF-A mRNA splicing is a therapeutic target for analgesia. Neurobiol Dis 2014; 71:245-59. [PMID: 25151644 PMCID: PMC4194316 DOI: 10.1016/j.nbd.2014.08.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/29/2014] [Accepted: 08/06/2014] [Indexed: 12/02/2022] Open
Abstract
Vascular endothelial growth factor-A (VEGF-A) is best known as a key regulator of the formation of new blood vessels. Neutralization of VEGF-A with anti-VEGF therapy e.g. bevacizumab, can be painful, and this is hypothesized to result from a loss of VEGF-A-mediated neuroprotection. The multiple vegf-a gene products consist of two alternatively spliced families, typified by VEGF-A165a and VEGF-A165b (both contain 165 amino acids), both of which are neuroprotective. Under pathological conditions, such as in inflammation and cancer, the pro-angiogenic VEGF-A165a is upregulated and predominates over the VEGF-A165b isoform. We show here that in rats and mice VEGF-A165a and VEGF-A165b have opposing effects on pain, and that blocking the proximal splicing event – leading to the preferential expression of VEGF-A165b over VEGF165a – prevents pain in vivo. VEGF-A165a sensitizes peripheral nociceptive neurons through actions on VEGFR2 and a TRPV1-dependent mechanism, thus enhancing nociceptive signaling. VEGF-A165b blocks the effect of VEGF-A165a. After nerve injury, the endogenous balance of VEGF-A isoforms switches to greater expression of VEGF-Axxxa compared to VEGF-Axxxb, through an SRPK1-dependent pre-mRNA splicing mechanism. Pharmacological inhibition of SRPK1 after traumatic nerve injury selectively reduced VEGF-Axxxa expression and reversed associated neuropathic pain. Exogenous VEGF-A165b also ameliorated neuropathic pain. We conclude that the relative levels of alternatively spliced VEGF-A isoforms are critical for pain modulation under both normal conditions and in sensory neuropathy. Altering VEGF-Axxxa/VEGF-Axxxb balance by targeting alternative RNA splicing may be a new analgesic strategy. The different vegf-a splice variants, VEGF-A165a and VEGF-A165b have pro- and anti-nociceptive actions respectively. Pro-nociceptive actions of VEGF-A165a are dependent on TRPV1. Alternative pre-mRNA splicing underpins peripheral sensitization by VEGF-A isoforms in normal and neuropathic animals.
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Affiliation(s)
- R P Hulse
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK; Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK
| | - N Beazley-Long
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK; School of Life Sciences, The Medical School, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK
| | - J Hua
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - H Kennedy
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - J Prager
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - H Bevan
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - Y Qiu
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | | | - M V Gammons
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | | | | | - A J Churchill
- Clinical Sciences, University of Bristol, Bristol BS1 2LX, UK
| | - S J Harper
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - S D Brain
- King's College London, London SE1 9NH, UK
| | - D O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK.
| | - L F Donaldson
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK; School of Life Sciences, The Medical School, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK.
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Hughes SW, Hickey L, Hulse RP, Lumb BM, Pickering AE. Endogenous analgesic action of the pontospinal noradrenergic system spatially restricts and temporally delays the progression of neuropathic pain following tibial nerve injury. Pain 2013; 154:1680-1690. [PMID: 23707289 PMCID: PMC3763373 DOI: 10.1016/j.pain.2013.05.010] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 04/26/2013] [Accepted: 05/03/2013] [Indexed: 11/17/2022]
Abstract
Pontospinal noradrenergic neurons form part of an endogenous analgesic system that suppresses acute pain, but there is conflicting evidence about its role in neuropathic pain. We investigated the chronology of descending noradrenergic control during the development of a neuropathic pain phenotype in rats following tibial nerve transection (TNT). A lumbar intrathecal cannula was implanted at the time of nerve injury allowing administration of selective α-adrenoceptor (α-AR) antagonists to sequentially assay their effects upon the expression of allodynia and hyperalgesia. Following TNT animals progressively developed mechanical and cold allodynia (by day 10) and subsequently heat hypersensitivity (day 17). Blockade of α2-AR with intrathecal yohimbine (30 μg) revealed earlier ipsilateral sensitization of all modalities while prazosin (30 μg, α1-AR) was without effect. Established allodynia (by day 21) was partly reversed by the re-uptake inhibitor reboxetine (5 μg, i.t.) but yohimbine no longer had any sensitising effect. This loss of effect coincided with a reduction in the descending noradrenergic innervation of the ipsilateral lumbar dorsal horn. Yohimbine reversibly unmasked contralateral hindlimb allodynia and hyperalgesia of all modalities and increased dorsal horn c-fos expression to an innocuous brush stimulus. Contralateral thermal hyperalgesia was also reversibly uncovered by yohimbine administration in a contact heat ramp paradigm in anaesthetised TNT rats. Following TNT there is an engagement of inhibitory α2-AR-mediated noradrenergic tone which completely masks contralateral and transiently suppresses the development of ipsilateral sensitization. This endogenous analgesic system plays a key role in shaping the spatial and temporal expression of the neuropathic pain phenotype after nerve injury.
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Affiliation(s)
- S W Hughes
- School of Physiology & Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
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