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Hirai T, Enomoto M, Kaburagi H, Sotome S, Yoshida-Tanaka K, Ukegawa M, Kuwahara H, Yamamoto M, Tajiri M, Miyata H, Hirai Y, Tominaga M, Shinomiya K, Mizusawa H, Okawa A, Yokota T. Intrathecal AAV serotype 9-mediated delivery of shRNA against TRPV1 attenuates thermal hyperalgesia in a mouse model of peripheral nerve injury. Mol Ther 2013; 22:409-419. [PMID: 24322332 DOI: 10.1038/mt.2013.247] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 10/17/2013] [Indexed: 01/03/2023] Open
Abstract
Gene therapy for neuropathic pain requires efficient gene delivery to both central and peripheral nervous systems. We previously showed that an adenoassociated virus serotype 9 (AAV9) vector expressing short-hairpin RNA (shRNA) could suppress target molecule expression in the dorsal root ganglia (DRG) and spinal cord upon intrathecal injection. To evaluate the therapeutic potential of this approach, we constructed an AAV9 vector encoding shRNA against vanilloid receptor 1 (TRPV1), which is an important target gene for acute pain, but its role in chronic neuropathic pain remains unclear. We intrathecally injected it into the subarachnoid space at the upper lumbar spine of mice 3 weeks after spared nerve injury (SNI). Delivered shTRPV1 effectively suppressed mRNA and protein expression of TRPV1 in the DRG and spinal cord, and it attenuated nerve injury-induced thermal allodynia 10-28 days after treatment. Our study provides important evidence for the contribution of TRPV1 to thermal hypersensitivity in neuropathic pain and thus establishes intrathecal AAV9-mediated gene delivery as an investigative and potentially therapeutic platform for the nervous system.
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Affiliation(s)
- Takashi Hirai
- Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Mitsuhiro Enomoto
- Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
| | - Hidetoshi Kaburagi
- Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shinichi Sotome
- Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kie Yoshida-Tanaka
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Madoka Ukegawa
- Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hiroya Kuwahara
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Mariko Yamamoto
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Mio Tajiri
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Haruka Miyata
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yukihiko Hirai
- Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan
| | - Makoto Tominaga
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki, Japan
| | - Kenichi Shinomiya
- Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hidehiro Mizusawa
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Atsushi Okawa
- Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takanori Yokota
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
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102
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Abstract
Inflammation is the process by which an organism responds to tissue injury involving both immune cell recruitment and mediator release. Diverse causes of neuropathic pain are associated with excessive inflammation in both the peripheral and central nervous system which may contribute to the initiation and maintenance of persistent pain. Chemical mediators, such as cytokines, chemokines, and lipid mediators, released during an inflammatory response have the undesired effect of sensitizing and stimulating nociceptors, their central synaptic targets or both. These changes can promote long-term maladaptive plasticity resulting in persistent neuropathic pain. This review aims to provide an overview of inflammatory mechanisms at differing levels of the sensory neuroaxis with a focus on neuropathic pain. We will compare and contrast neuropathic pain states such as traumatic nerve injury which is associated with a vigorous inflammatory response and chemotherapy induced pain in which the inflammatory response is much more modest. Targeting excessive inflammation in neuropathic pain provides potential therapeutic opportunities and we will discuss some of the opportunities but also the clinical challenges in such an approach.
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Affiliation(s)
- A Ellis
- King's College London, Wolfson Wing, Hodgkin Building, Guy's Campus, London SE1 1UL, UK.
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103
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Newman TA, Bailey JL, Stocker LJ, Woo YL, Macklon NS, Cheong YC. Expression of neuronal markers in the endometrium of women with and those without endometriosis. Hum Reprod 2013; 28:2502-10. [PMID: 23820422 DOI: 10.1093/humrep/det274] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
STUDY QUESTION How do the expression patterns of neuronal markers differ in the endometrium of women with and without endometriosis? SUMMARY ANSWER The neuronal markers, PGP9.5, NGFp75 and VR1, are expressed in the endometrium at levels that do not differ between women with and without endometriosis. WHAT IS KNOWN ALREADY Aberrant neuronal growth within the uterus may contribute to abnormal fertility and uterine dysfunction. However, controversy still exists as to whether aberrant innervation in the endometrium is associated with gynaecological pathology such as endometriosis. This may reflect the use of subjective methods such as histology to assess the innervation of the endometrium. We, therefore, employed a quantitative method, western blotting, to study markers of endometrial innervation in the presence and absence of endometriosis. STUDY DESIGN, SIZE, DURATION This study included 45 women undergoing laparoscopic examination for the diagnosis of endometriosis. Endometrial samples were analysed by western blot for the expression of neuronal and neurotrophic markers, PGP9.5, VR1 and NGFp75. PARTICIPANTS/MATERIALS, SETTINGS, METHODS Endometrial pipelle biopsies were obtained from patients with (n = 20, study group) and without (n = 25, control group) endometriosis. Tissue was analysed by immunohistochemistry and western blot analysis for the expression of pan-neuronal marker, PGP9.5, sensory nociceptive marker, TPVR1, and low-affinity neurotrophic growth factor receptor, NGFRp75. MAIN RESULTS AND THE ROLE OF CHANCE PGP9.5, NGFp75 and VR1 were expressed in the endometrium of women, independent of the presence of endometriosis. Furthermore, the expression level of PGP9.5, VR1 and NGFp75 did not alter between the two cohorts of women. LIMITATIONS, REASONS FOR CAUTION Studies of this nature are subject to the heterogeneous nature of patient population and tissue samples despite attempts to standardize these parameters. Hence, further studies using similar methodology will be required to confirm our results. WIDER IMPLICATIONS OF THE FINDINGS Our results highlight that sensory neuronal markers are present in women with and without endometriosis. Future work will assess what the targets of the endometrial nerves are and investigate their function, their impact on endometrial biology and, in particular, whether aberrant neuronal function, rather than the mere presence of neuronal function, could be the root cause of subfertility and/or pain affecting many endometriosis sufferers. Our results do not, however, confirm the previous paradigm of increased innervation in the endometrium of women with endometriosis, nor the use of nerve cell detection from pipelle biopsies to diagnose endometriosis.
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Affiliation(s)
- T A Newman
- CES, Medicine, Institute of Life Sciences, University of Southampton, Southampton, UK
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104
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Labuz D, Machelska H. Stronger antinociceptive efficacy of opioids at the injured nerve trunk than at its peripheral terminals in neuropathic pain. J Pharmacol Exp Ther 2013; 346:535-44. [PMID: 23820126 DOI: 10.1124/jpet.113.205344] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activation of opioid receptors on peripheral sensory neurons has the potential for safe pain control, as it lacks centrally mediated side effects. While this approach often only partially suppressed neuropathic pain in animal models, opioids were mostly applied to animal paws although neuropathy was induced at the nerve trunk. Here we aimed to identify the most relevant peripheral site of opioid action for efficient antinociception in neuropathy. On days 2 and 14 following a chronic constriction injury (CCI) of the sciatic nerve in mice, we evaluated dose and time relationships of the effects of μ-, δ-, and κ-opioid receptor agonists injected either at the CCI site or intraplantarly (i.pl.) into the lesioned nerve-innervated paw, on spontaneous paw lifting and heat and mechanical hypersensitivity (using Hargreaves and von Frey tests, respectively). We found that neither agonist diminished spontaneous paw lifting, despite the application site. Heat hypersensitivity was partially attenuated by i.pl. μ-receptor agonist only, while it was improved by all three agonists applied at the CCI site. Mechanical hypersensitivity was slightly diminished by all agonists administered i.pl., whereas it was completely blocked by all opioids injected at the CCI site. These antinociceptive effects were opioid receptor type-selective and site-specific. Thus, opioids might not be effective against spontaneous pain, but they improve heat and mechanical hypersensitivity in neuropathy. Importantly, efficient alleviation of hypersensitivity is governed by peripheral opioid receptors at the injured nerve trunk rather than at its peripheral terminals. Identifying the primary action site of analgesics is important for the development of adequate pain therapies.
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Affiliation(s)
- Dominika Labuz
- Klinik für Anästhesiologie und operative Intensivmedizin, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
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105
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Wu Z, Yang Q, Crook RJ, O'Neil RG, Walters ET. TRPV1 channels make major contributions to behavioral hypersensitivity and spontaneous activity in nociceptors after spinal cord injury. Pain 2013; 154:2130-2141. [PMID: 23811042 DOI: 10.1016/j.pain.2013.06.040] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 06/18/2013] [Accepted: 06/24/2013] [Indexed: 12/27/2022]
Abstract
Chronic neuropathic pain is often a severe and inadequately treated consequence of spinal cord injury (SCI). Recent findings suggest that SCI pain is promoted by spontaneous activity (SA) generated chronically in cell bodies of primary nociceptors in dorsal root ganglia (DRG). Many nociceptors express transient receptor potential V1 (TRPV1) channels, and in a preceding study most dissociated DRG neurons exhibiting SA were excited by the TRPV1 activator, capsaicin. The present study investigated roles of TRPV1 channels in behavioral hypersensitivity and nociceptor SA after SCI. Contusive SCI at thoracic segment T10 increased expression of TRPV1 protein in lumbar DRG 1 month after injury and enhanced capsaicin-evoked ion currents and Ca2+ responses in dissociated small DRG neurons. A major role for TRPV1 channels in pain-related behavior was indicated by the ability of a specific TRPV1 antagonist, AMG9810, to reverse SCI-induced hypersensitivity of hind limb withdrawal responses to mechanical and thermal stimuli at a dose that did not block detection of noxious heat. Similar reversal of behavioral hypersensitivity was induced by intrathecal oligodeoxynucleotides antisense to TRPV1, which knocked down TRPV1 protein and reduced capsaicin-evoked currents. TRPV1 knockdown also decreased the incidence of SA in dissociated nociceptors after SCI. Prolonged application of very low concentrations of capsaicin produced nondesensitizing firing similar to SA, and this effect was enhanced by prior SCI. These results show that TRPV1 makes important contributions to pain-related hypersensitivity long after SCI, and suggest a role for TRPV1-dependent enhancement of nociceptor SA that offers a promising target for treating chronic pain after SCI.
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Affiliation(s)
- Zizhen Wu
- Department of Integrative Biology and Pharmacology, The University of Texas Medical School at Houston, Houston, TX 77030, USA
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106
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Min JW, Liu WH, He XH, Peng BW. Different types of toxins targeting TRPV1 in pain. Toxicon 2013; 71:66-75. [PMID: 23732125 DOI: 10.1016/j.toxicon.2013.05.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 05/14/2013] [Accepted: 05/22/2013] [Indexed: 02/06/2023]
Abstract
The transient receptor potential vanilloid 1(TRPV1) channels are members of the transient receptor potential (TRP) superfamily. Members of this family are expressed in primary sensory neurons and are best known for their role in nociception and sensory transmission. Multiple painful stimuli can activate these channels. In this review, we discussed the mechanisms of different types of venoms that target TRPV1, such as scorpion venom, botulinum neurotoxin, spider toxin, ciguatera fish poisoning (CFP) and neurotoxic shellfish poisoning (NSP). Some of these toxins activate TRPV1; however, some do not. Regardless of TRPV1 inhibition or activation, they occur through different pathways. For example, BoNT/A decreases TRPV1 expression levels by blocking TRPV1 trafficking to the plasma membrane, although the exact mechanism is still under debate. Vanillotoxins from tarantula (Psalmopoeus cambridgei) are proposed to activate TRPV1 via interaction with a region of TRPV1 that is homologous to voltage-dependent ion channels. Here, we offer a description of the present state of knowledge for this complex subject.
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Affiliation(s)
- Jia-Wei Min
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, 185 Donghu Road, Wuhan, Hubei 430071, PR China
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107
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Abe T, Shimoda T, Urade M, Hasegawa M, Sugiyo S, Takemura M. c-Fos induction in the brainstem following electrical stimulation of the trigeminal ganglion of chronically mandibular nerve-transected rats. Somatosens Mot Res 2013; 30:175-84. [DOI: 10.3109/08990220.2013.790805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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108
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Lee JY, Shin TJ, Choi JM, Seo KS, Kim HJ, Yoon TG, Lee YS, Han H, Chung HJ, Oh Y, Jung SJ, Shin KJ. Antinociceptive curcuminoid, KMS4034, effects on inflammatory and neuropathic pain likely via modulating TRPV1 in mice. Br J Anaesth 2013; 111:667-72. [PMID: 23719767 DOI: 10.1093/bja/aet176] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Curcumin, the active ingredient of turmeric (Curcuma longa), has a wide range of beneficial effects including anti-inflammation and analgesia. However, poor bioavailability of curcumin hinders its clinical application. To overcome this limitation, we modified the structure of curcumin and synthesized new derivatives with favourable pharmacokinetic profiles. Recently, curcumin has been shown to have an antagonizing effect on transient receptor potential vanilloid type 1 (TRPV1) ion channels. We investigated the antinociceptive activity of KMS4034 which had the most favourable pharmacokinetics among the tested curcumin derivatives. METHODS To evaluate the mechanism of the antinociceptive effects of KMS4034, capsaicin (I(CAP))- and heat (I(heat))-induced currents in TRPV1 expressing HEK293 cells were observed after the application of KMS4034. Nociceptive behavioural measurement using the hot-plate test, formalin test, and chronic constriction injury (CCI) model were evaluated in mice. Also, calcitonin gene-related peptide (CGRP) was stained immunohistochemically in the L4/5 dorsal horns in mice with neuropathic pain. RESULTS I(CAP) (P<0.01) and I(heat) (P<0.05) of TRPV1 were significantly blocked by 10 μM KMS4034. Behaviourally, noticeable antinociceptive effects after 10 mg kg(-1) of KMS4034 treatment were observed in the first (P<0.05) and second phases (P<0.05) of the formalin and hot-plate tests. The mechanical threshold of CCI mice treated with 10 mg kg(-1) KMS4034 was significantly increased compared with control. Immunohistochemical CGRP expression was decreased in the lamina I-II of the lumbar dorsal horns in KMS4034-treated CCI mice compared with the control (P<0.05). CONCLUSIONS KMS4034 may be an effective analgesic for various pain conditions.
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Affiliation(s)
- J Y Lee
- Department of Dental Anesthesiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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109
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Hara T, Chiba T, Abe K, Makabe A, Ikeno S, Kawakami K, Utsunomiya I, Hama T, Taguchi K. Effect of paclitaxel on transient receptor potential vanilloid 1 in rat dorsal root ganglion. Pain 2013; 154:882-9. [PMID: 23602343 DOI: 10.1016/j.pain.2013.02.023] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 01/28/2013] [Accepted: 02/22/2013] [Indexed: 11/19/2022]
Abstract
Peripheral neuropathy is a common adverse effect of paclitaxel treatment. To analyze the contribution of transient receptor potential vanilloid 1 (TRPV1) in the development of paclitaxel-induced thermal hyperalgesia, TRPV1 expression in the rat dorsal root ganglion (DRG) was analyzed after paclitaxel treatment. Behavioral assessment using the tail-flick test showed that intraperitoneal administration of 2 and 4 mg/kg paclitaxel induced thermal hyperalgesia after days 7, 14, and 21. Paclitaxel-induced thermal hyperalgesia after day 14 was significantly inhibited by the TRP antagonist ruthenium red (3 mg/kg, s.c.) and the TRPV1 antagonist capsazepine (30 mg/kg, s.c.). Paclitaxel (2 and 4 mg/kg) treatment increased the expression of TRPV1 mRNA and protein in DRG neurons. Immunohistochemistry showed that paclitaxel (4 mg/kg) treatment increased TRPV1 protein expression in small and medium DRG neurons 14 days after treatment. Antibody double labeling revealed that isolectin B4-positive small DRG neurons co-expressed TRPV1. TRPV1 immunostaining was up-regulated in paw skin day 14 after paclitaxel treatment. Moreover, in situ hybridization histochemistry revealed that most of the TRPV1 mRNA-labeled neurons in the DRG were small or medium in size. These results suggest that paclitaxel treatment increases TRPV1 expression in DRG neurons and may contribute to functional peripheral neuropathic pain.
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Affiliation(s)
- Tomomi Hara
- Department of Medicinal Pharmacology, Showa Pharmaceutical University, Machida, Tokyo, Japan
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110
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Differential effects of peripheral versus central coadministration of QX-314 and capsaicin on neuropathic pain in rats. Anesthesiology 2012; 117:365-80. [PMID: 22739765 DOI: 10.1097/aln.0b013e318260de41] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Neuropathic pain is common and difficult to treat. Recently a technique was developed to selectively inhibit nociceptive inputs by simultaneously applying two drugs: capsaicin, a transient receptor potential vanilloid receptor-1 channel activator, and QX-314, a lidocaine derivative that intracellularly blocks sodium channels. We used this technique to investigate whether transient receptor potential vanilloid receptor 1-expressing nociceptors contribute to neuropathic pain. METHODS The rat chronic constriction injury model was used to induce neuropathic pain in order to test the analgesic effects of both peripheral (perisciatic) and central (intrathecal) administration of the QX-314/capsaicin combination. The Hargreaves and von Frey tests were used to monitor evoked pain-like behaviors and visual observations were used to rank spontaneous pain-like behaviors. RESULTS Perisciatic injections of the QX-314/capsaicin combination transiently increased the withdrawal thresholds by approximately 3-fold, for mechanical and thermal stimuli in rats (n = 6/group) with nerve injuries suggesting that peripheral transient receptor potential vanilloid receptor 1-expressing nociceptors contribute to neuropathic pain. In contrast, intrathecal administration of the QX-314/capsaicin combination did not alleviate pain-like behaviors (n = 5/group). Surprisingly, intrathecal QX-314 alone (n = 9) or in combination with capsaicin (n = 8) evoked spontaneous pain-like behaviors. CONCLUSIONS Data from the perisciatic injections suggested that a component of neuropathic pain was mediated by peripheral nociceptive inputs. The role of central nociceptive terminals could not be determined because of the severe side effects of the intrathecal drug combination. We concluded that only peripheral blockade of transient receptor potential vanilloid receptor 1-expressing nociceptive afferents by the QX-314/capsaicin combination was effective at reducing neuropathic allodynia and hyperalgesia.
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111
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Zakir HM, Mostafeezur RM, Suzuki A, Hitomi S, Suzuki I, Maeda T, Seo K, Yamada Y, Yamamura K, Lev S, Binshtok AM, Iwata K, Kitagawa J. Expression of TRPV1 channels after nerve injury provides an essential delivery tool for neuropathic pain attenuation. PLoS One 2012; 7:e44023. [PMID: 22962595 PMCID: PMC3433461 DOI: 10.1371/journal.pone.0044023] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 08/01/2012] [Indexed: 01/06/2023] Open
Abstract
Increased expression of the transient receptor potential vanilloid 1 (TRPV1) channels, following nerve injury, may facilitate the entry of QX-314 into nociceptive neurons in order to achieve effective and selective pain relief. In this study we hypothesized that the level of QX-314/capsaicin (QX-CAP) - induced blockade of nocifensive behavior could be used as an indirect in-vivo measurement of functional expression of TRPV1 channels. We used the QX-CAP combination to monitor the functional expression of TRPV1 in regenerated neurons after inferior alveolar nerve (IAN) transection in rats. We evaluated the effect of this combination on pain threshold at different time points after IAN transection by analyzing the escape thresholds to mechanical stimulation of lateral mental skin. At 2 weeks after IAN transection, there was no QX-CAP mediated block of mechanical hyperalgesia, implying that there was no functional expression of TRPV1 channels. These results were confirmed immunohistochemically by staining of regenerated trigeminal ganglion (TG) neurons. This suggests that TRPV1 channel expression is an essential necessity for the QX-CAP mediated blockade. Furthermore, we show that 3 and 4 weeks after IAN transection, application of QX-CAP produced a gradual increase in escape threshold, which paralleled the increased levels of TRPV1 channels that were detected in regenerated TG neurons. Immunohistochemical analysis also revealed that non-myelinated neurons regenerated slowly compared to myelinated neurons following IAN transection. We also show that TRPV1 expression shifted towards myelinated neurons. Our findings suggest that nerve injury modulates the TRPV1 expression pattern in regenerated neurons and that the effectiveness of QX-CAP induced blockade depends on the availability of functional TRPV1 receptors in regenerated neurons. The results of this study also suggest that the QX-CAP based approach can be used as a new behavioral tool to detect dynamic changes in TRPV1 expression, in various pathological conditions.
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Affiliation(s)
- Hossain Md. Zakir
- Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Rahman Md. Mostafeezur
- Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Akiko Suzuki
- Division of Oral Anatomy, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Suzuro Hitomi
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
| | - Ikuko Suzuki
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
| | - Takeyasu Maeda
- Division of Oral Anatomy, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kenji Seo
- Division of Dental Anesthesiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yoshiaki Yamada
- Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kensuke Yamamura
- Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Shaya Lev
- Department of Medical Neurobiology, Institute for Medical Research Israel Canada and Center for Research on Pain, The Hebrew University Medical School, Jerusalem, Israel
| | - Alexander M. Binshtok
- Department of Medical Neurobiology, Institute for Medical Research Israel Canada and Center for Research on Pain, The Hebrew University Medical School, Jerusalem, Israel
| | - Koichi Iwata
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
| | - Junichi Kitagawa
- Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- * E-mail:
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112
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Han P, Korepanova AV, Vos MH, Moreland RB, Chiu ML, Faltynek CR. Quantification of TRPV1 Protein Levels in Rat Tissues to Understand its Physiological Roles. J Mol Neurosci 2012; 50:23-32. [DOI: 10.1007/s12031-012-9849-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 06/25/2012] [Indexed: 12/16/2022]
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113
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Djouhri L, Fang X, Koutsikou S, Lawson SN. Partial nerve injury induces electrophysiological changes in conducting (uninjured) nociceptive and nonnociceptive DRG neurons: Possible relationships to aspects of peripheral neuropathic pain and paresthesias. Pain 2012; 153:1824-1836. [PMID: 22721911 PMCID: PMC3425771 DOI: 10.1016/j.pain.2012.04.019] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 03/25/2012] [Accepted: 04/23/2012] [Indexed: 01/24/2023]
Abstract
Partial nerve injury leads to peripheral neuropathic pain. This injury results in conducting/uninterrupted (also called uninjured) sensory fibres, conducting through the damaged nerve alongside axotomised/degenerating fibres. In rats seven days after L5 spinal nerve axotomy (SNA) or modified-SNA (added loose-ligation of L4 spinal nerve with neuroinflammation-inducing chromic-gut), we investigated a) neuropathic pain behaviours and b) electrophysiological changes in conducting/uninterrupted L4 dorsal root ganglion (DRG) neurons with receptive fields (called: L4-receptive-field-neurons). Compared to pretreatment, modified-SNA rats showed highly significant increases in spontaneous-foot-lifting duration, mechanical-hypersensitivity/allodynia, and heat-hypersensitivity/hyperalgesia, that were significantly greater than after SNA, especially spontaneous-foot-lifting. We recorded intracellularly in vivo from normal L4/L5 DRG neurons and ipsilateral L4-receptive-field-neurons. After SNA or modified-SNA, L4-receptive-field-neurons showed the following: a) increased percentages of C-, Ad-, and Ab-nociceptors and cutaneous Aa/b-low-threshold mechanoreceptors with ongoing/spontaneous firing; b) spontaneous firing in C-nociceptors that originated peripherally; this was at a faster rate in modified-SNA than SNA; c) decreased electrical thresholds in A-nociceptors after SNA; d) hyperpolarised membrane potentials in A-nociceptors and Aa/b-low-threshold-mechanoreceptors after SNA, but not C-nociceptors; e) decreased somatic action potential rise times in C- and A-nociceptors, not Aa/b-low-threshold-mechanoreceptors. We suggest that these changes in subtypes of conducting/uninterrupted neurons after partial nerve injury contribute to the different aspects of neuropathic pain as follows: spontaneous firing in nociceptors to ongoing/spontaneous pain; spontaneous firing in Aa/b-low-threshold-mechanoreceptors to dysesthesias/paresthesias; and lowered A-nociceptor electrical thresholds to A-nociceptor sensitization, and greater evoked pain.
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Affiliation(s)
- Laiche Djouhri
- School of Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
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114
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von Hehn CA, Baron R, Woolf CJ. Deconstructing the neuropathic pain phenotype to reveal neural mechanisms. Neuron 2012; 73:638-52. [PMID: 22365541 PMCID: PMC3319438 DOI: 10.1016/j.neuron.2012.02.008] [Citation(s) in RCA: 582] [Impact Index Per Article: 48.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2012] [Indexed: 01/01/2023]
Abstract
After nerve injury maladaptive changes can occur in injured sensory neurons and along the entire nociceptive pathway within the CNS, which may lead to spontaneous pain or pain hypersensitivity. The resulting neuropathic pain syndromes present as a complex combination of negative and positive symptoms, which vary enormously from individual to individual. This variation depends on a diversity of underlying pathophysiological changes resulting from the convergence of etiological, genotypic, and environmental factors. The pain phenotype can serve therefore, as a window on underlying pathophysiological neural mechanisms and as a guide for developing personalized pain medicine.
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Affiliation(s)
- Christian A von Hehn
- FM Kirby Neurobiology Center, Children's Hospital Boston, and Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
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Brandt MR, Beyer CE, Stahl SM. TRPV1 Antagonists and Chronic Pain: Beyond Thermal Perception. Pharmaceuticals (Basel) 2012; 5:114-32. [PMID: 24288084 PMCID: PMC3763634 DOI: 10.3390/ph5020114] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 01/18/2012] [Accepted: 01/26/2012] [Indexed: 12/15/2022] Open
Abstract
In the last decade, considerable evidence as accumulated to support the development of Transient Receptor Potential Vanilloid 1 (TRPV1) antagonists for the treatment of various chronic pain conditions. Whereas there is a widely accepted rationale for the development of TRPV1 antagonists for the treatment of various inflammatory pain conditions, their development for indications of chronic pain, where conditions of tactical, mechanical and spontaneous pain predominate, is less clear. Preclinical localization and expression studies provide a firm foundation for the use of molecules targeting TRPV1 for conditions of bone pain, osteoarthritis and neuropathic pain. Selective TRPV1 antagonists weakly attenuate tactile and mechanical hypersensivity and are partially effective for behavioral and electrophysiological endpoints that incorporate aspects of spontaneous pain. While initial studies with TRPV1 antagonist in normal human subjects indicate a loss of warm thermal perception, clinical studies assessing allelic variants suggests that TRPV1 may mediate other sensory modalities under certain conditions. The focus of this review is to summarize the current perspectives of TRPV1 for the treatment of conditions beyond those with a primary thermal sensitivity.
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Affiliation(s)
- Michael R. Brandt
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
- IteraMed L.L.C., Doylestown, PA 18902, USA
- Author to whom correspondence should be addressed; ; Tel.: +1-908-303-5250
| | | | - Stephen M. Stahl
- Neuroscience Education Institute, University of California San Diego, Carlsbad, CA 92008, USA;
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116
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Palazzo E, Luongo L, de Novellis V, Rossi F, Marabese I, Maione S. Transient receptor potential vanilloid type 1 and pain development. Curr Opin Pharmacol 2012; 12:9-17. [DOI: 10.1016/j.coph.2011.10.022] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 10/27/2011] [Accepted: 10/28/2011] [Indexed: 02/06/2023]
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117
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Nickel FT, Seifert F, Lanz S, Maihöfner C. Mechanisms of neuropathic pain. Eur Neuropsychopharmacol 2012; 22:81-91. [PMID: 21672666 DOI: 10.1016/j.euroneuro.2011.05.005] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 04/12/2011] [Accepted: 05/14/2011] [Indexed: 12/14/2022]
Abstract
Neuropathic pain is a disease of global burden. Its symptoms include spontaneous and stimulus-evoked painful sensations. Several maladaptive mechanisms underlying these symptoms have been elucidated in recent years: peripheral sensitization of nociception, abnormal excitability of afferent neurons, central sensitization comprising pronociceptive facilitation, disinhibition of nociception and central reorganization processes, and sympathetically maintained pain. This review aims to illustrate these pathophysiological principles, focussing on molecular and neurophysiological findings. Finally therapeutic options based on these findings are discussed.
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Affiliation(s)
- Florian T Nickel
- Department of Neurology, University of Erlangen-Nuremberg, Germany
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118
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Wang J, Cao DY, Guo Y, Ma SJ, Luo R, Pickar JG, Zhao Y. Octreotide inhibits capsaicin-induced activation of C and Aδ afferent fibres in rat hairy skin in vivo. Clin Exp Pharmacol Physiol 2012; 38:521-7. [PMID: 21595740 DOI: 10.1111/j.1440-1681.2011.05542.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
1. The present study investigated whether the somatostatin receptor (SSTR) agonist, octreotide, could inhibit the activation of dorsal skin afferent fibres induced by local injection of capsaicin in the rat. 2. Single unit activity from Aδ mechano-heat sensitive (AMH; n = 41) and C mechano-heat sensitive (CMH; n = 30) afferents was recorded after their isolation in thin filaments from the dorsal cutaneous nerve branches. The effect of subcutaneous octreotide injection on the change in discharge rate and mechanical threshold induced by capsaicin was determined. 3. Capsaicin (0.05%) injection into the edge of the receptive field of both AMH and CMH units increased their discharge rate and decreased their mechanical threshold. Pre-injection of octreotide inhibited these responses, and co-application of SSTR antagonist, cyclosomatostatin, reversed the inhibitory effect of octreotide. 4. The present study provides electrophysiological evidence that the signal evoked by the somatostatin receptor inhibits the activation and mechanical sensitization evoked by capsaicin in the terminals in small-diameter sensory neurons.
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Affiliation(s)
- Jun Wang
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Medicine, Shaanxi, China
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119
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Sadofsky LR, Ramachandran R, Crow C, Cowen M, Compton SJ, Morice AH. Inflammatory stimuli up-regulate transient receptor potential vanilloid-1 expression in human bronchial fibroblasts. Exp Lung Res 2012; 38:75-81. [PMID: 22242698 DOI: 10.3109/01902148.2011.644027] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Lung fibroblasts are involved in interstitial lung disease, chronic asthma, and chronic obstructive pulmonary disease (COPD). The expanded fibroblast population in airway disease leads to airway remodeling and contributes to the inflammatory process seen in these diseases. The cation channel transient receptor potential vanilloid-1 (TRPV1) is activated by noxious stimuli, including capsaicin, protons, and high temperatures and is thought to have a role in inflammation. Although TRPV1 expression is primarily reported to be neuronal, some extraneuronal expression has been reported. The authors therefore sought to determine whether human primary bronchial fibroblasts (HPBFs) express TRPV1 and whether inflammatory mediators can induce TRPV1 expression. The authors show that fibroblasts are predominantly TRPV1 negative; however, following stimulation with 3 common inflammatory mediators, tumor necrosis factor α (TNF-α), lipopolysaccharide (LPS), and interleukin-1α (IL-1α), TRPV1 mRNA was observed at 24 and 48 hours post treatment with all 3 mediators. Using Western blotting an increase in TRPV1 expression with all 3 inflammatory mediators was detected with significant increases seen at 72 hours post LPS and IL-1α treatment. In stark contrast to the untreated fibroblasts, significant calcium signaling in response to capsaicin and resiniferatoxin in HPBFs treated for 24 and 48 hours with TNF-α, LPS, or IL-1α was also observed. These results indicate that TRPV1 can be expressed on bronchial fibroblasts in situations where an underlying inflammatory stimulus exists, as is the case in airway diseases such as asthma and COPD.
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Affiliation(s)
- Laura R Sadofsky
- Cardiovascular and Respiratory Studies, University of Hull, Castle Hill Hospital, Cottingham, East Yorkshire, UK.
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120
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Urano H, Ara T, Fujinami Y, Hiraoka BY. Aberrant TRPV1 expression in heat hyperalgesia associated with trigeminal neuropathic pain. Int J Med Sci 2012; 9:690-7. [PMID: 23091405 PMCID: PMC3477677 DOI: 10.7150/ijms.4706] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 09/06/2012] [Indexed: 12/24/2022] Open
Abstract
Trigeminal neuropathic pain is a facial pain syndrome associated with trigeminal nerve injury. However, the mechanism of trigeminal neuropathic pain is poorly understood. This study aimed to determine the role of transient receptor potential vanilloid 1 (TRPV1) in heat hyperalgesia in a trigeminal neuropathic pain model. We evaluated nociceptive responses to mechanical and heat stimuli using a partial infraorbital nerve ligation (pIONL) model. Withdrawal responses to mechanical and heat stimuli to vibrissal pads (VP) were assessed using von Frey filaments and a thermal stimulator equipped with a heat probe, respectively. Changes in withdrawal responses were measured after subcutaneous injection of the TRP channel antagonist capsazepine. In addition, the expression of TRPV1 in the trigeminal ganglia was examined. Mechanical allodynia and heat hyperalgesia were observed in VP by pIONL. Capsazepine suppressed heat hyperalgesia but not mechanical allodynia. The number of TRPV1-positive neurons in the trigeminal ganglia was significantly increased in the large-diameter-cell group. These results suggest that TRPV1 plays an important role in the heat hyperalgesia observed in the pIONL model.
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Affiliation(s)
- Hiroko Urano
- Institute for Oral Science, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan
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121
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Fukuoka T, Yamanaka H, Kobayashi K, Okubo M, Miyoshi K, Dai Y, Noguchi K. Re-evaluation of the phenotypic changes in L4 dorsal root ganglion neurons after L5 spinal nerve ligation. Pain 2012; 153:68-79. [DOI: 10.1016/j.pain.2011.09.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 08/29/2011] [Accepted: 09/12/2011] [Indexed: 11/25/2022]
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122
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New strategies to develop novel pain therapies: addressing thermoreceptors from different points of view. Pharmaceuticals (Basel) 2011; 5:16-48. [PMID: 24288041 PMCID: PMC3763626 DOI: 10.3390/ph5010016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 12/16/2011] [Accepted: 12/21/2011] [Indexed: 01/23/2023] Open
Abstract
One approach to develop successful pain therapies is the modulation of dysfunctional ion channels that contribute to the detection of thermal, mechanical and chemical painful stimuli. These ion channels, known as thermoTRPs, promote the sensitization and activation of primary sensory neurons known as nociceptors. Pharmacological blockade and genetic deletion of thermoTRP have validated these channels as therapeutic targets for pain intervention. Several thermoTRP modulators have progressed towards clinical development, although most failed because of the appearance of unpredicted side effects. Thus, there is yet a need to develop novel channel modulators with improved therapeutic index. Here, we review the current state-of-the art and illustrate new pharmacological paradigms based on TRPV1 that include: (i) the identification of activity-dependent modulators of this thermoTRP channel; (ii) the design of allosteric modulators that interfere with protein-protein interaction involved in the functional coupling of stimulus sensing and gate opening; and (iii) the development of compounds that abrogate the inflammation-mediated increase of receptor expression in the neuronal surface. These new sites of action represent novel strategies to modulate pathologically active TRPV1, while minimizing an effect on the TRPV1 subpopulation involved in physiological and protective roles, thus increasing their potential therapeutic use.
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123
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Electrical stimulation at distinct peripheral sites in spinal nerve injured rats leads to different afferent activation profiles. Neurosci Lett 2011; 505:52-7. [PMID: 22001268 DOI: 10.1016/j.neulet.2011.09.065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 08/20/2011] [Accepted: 09/28/2011] [Indexed: 11/23/2022]
Abstract
The neurophysiological basis by which neuromodulatory techniques lead to relief of neuropathic pain remains unclear. We investigated whether electrical stimulation at different peripheral sites induces unique profiles of A-fiber afferent activation in nerve-injured rats. At 4-6weeks after subjecting rats to L5 spinal nerve injury (SNL) or sham operation, we recorded the orthodromic compound action potential (AP) at the ipsilateral L4 dorsal root in response to (1) transcutaneous electrical nerve stimulation (TENS, a patch electrode placed on the dorsum of the foot), (2) subcutaneous electrical stimulation (SQS, electrode inserted subcutaneously along the dorsum of the foot), (3) peroneal nerve stimulation (PNS, electrode placed longitudinally abutting the nerve), and (4) sciatic nerve stimulation (SNS). The area under the Aα/β compound AP was measured as a function of the bipolar, constant-current stimulus intensity (0.02-6.0 mA, 0.2 ms). In both nerve-injured and sham-operated groups, the stimulus-response (S-R) functions of the Aα/β compound APs differed substantially with the stimulation site; SNS having the lowest threshold and largest compound AP waveform, followed by PNS, SQS, and TENS. The S-R function to PNS was shifted to the right in the SNL group, compared to that in the sham-operated group. The Aα/β-threshold to PNS was higher in the SNL group than in the sham-operated group. The S-R functions and Aα/β-thresholds to TENS and SQS were comparable between the two groups. Electrical stimulation of different peripheral targets induced distinctive profiles of A-fiber afferent activation, suggesting that the neuronal substrates for the various forms of peripheral neuromodulatory therapies may differ.
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124
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Han P, Korepanova AV, Vos MH, Pereda-Lopez A, Lake MR, Bianchi BR, Moreland RB, Faltynek CR, Chiu ML. Development of ELISA to measure TRPV1 protein in rat tissues. J Neurosci Methods 2011; 200:144-52. [DOI: 10.1016/j.jneumeth.2011.06.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 06/23/2011] [Accepted: 06/28/2011] [Indexed: 12/19/2022]
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125
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Abstract
The past decade has witnessed the cloning of a new family of ion channels that are responsive to temperature. Six of these transient receptor potential (TRP) channels are proposed to be involved in thermosensation and are located in sensory nerves and skin. The TRPV1, TRPV2, TRPV3, and TRPV4 channels have incompletely overlapping functions over a broad thermal range from warm to hot. Deletion of the individual TRPV1, TRPV3, and TRPV4 channels in mice has established their physiological role in thermosensation. In all cases thermosensation is not completely abolished - suggesting some functional redundancy among the channels. Notably, the TRPV2 channel is responsive to hot temperatures in heterologous systems, but its physiological relevance in vivo has not been established. Cool and cold temperatures are sensed by TRPM8 and TRPA1 family members. Currently, the pharmaceutical industry is developing agonists and antagonists for the various TRP channels. For instance, TRPV1 receptor agonists produce hypothermia, while antagonists induce hyperthermia. Recent investigations have found that different regions of the TRPV1 receptor are responsive to temperature, nociceptive stimuli, and various chemical agents. With this information, it has been possible to develop a TRPV1 compound that blocks responses to capsaicin and acid while leaving temperature sensitivity intact. These channels have important implications for hyperthermia research and may help to identify previously unexplored mechanisms in different tissues that are responsive to thermal stress.
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Affiliation(s)
- William C Wetsel
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA.
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126
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Leone C, Biasiotta A, La Cesa S, Di Stefano G, Cruccu G, Truini A. Pathophysiological mechanisms of neuropathic pain. FUTURE NEUROLOGY 2011. [DOI: 10.2217/fnl.11.23] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Neuropathic pain is a common problem in clinical practice and one that adversely affects patients’ quality of life. Converging evidence from animal and human studies demonstrates that neuropathic pain arises from a lesion in the somatosensory system. Injured peripheral nerve fibers give rise to an intense and prolonged ectopic input to the CNS and, in some cases, also to secondary changes in dorsal horn neuronal excitability. Convincing evidence now suggests that classifying neuropathic pain according to a mechanism-based rather than an etiology-based approach might help in targeting therapy to the individual patient and would be useful in testing new drugs. This article summarizes our current understanding of the peripheral and central pathophysiological mechanisms underlying neuropathic pain and focuses on how symptoms translate into mechanisms.
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Affiliation(s)
- Caterina Leone
- Department of Neurological Sciences, University La Sapienza, Viale Università 30 00185 – Rome, Italy
| | - Antonella Biasiotta
- Department of Neurological Sciences, University La Sapienza, Viale Università 30 00185 – Rome, Italy
| | - Silvia La Cesa
- Department of Neurological Sciences, University La Sapienza, Viale Università 30 00185 – Rome, Italy
| | - Giulia Di Stefano
- Department of Neurological Sciences, University La Sapienza, Viale Università 30 00185 – Rome, Italy
| | - Giorgio Cruccu
- Department of Neurological Sciences, University La Sapienza, Viale Università 30 00185 – Rome, Italy
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127
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Musumeci G, Grasselli G, Rossi S, De Chiara V, Musella A, Motta C, Studer V, Bernardi G, Haji N, Sepman H, Fresegna D, Maccarrone M, Mandolesi G, Centonze D. Transient receptor potential vanilloid 1 channels modulate the synaptic effects of TNF-α and of IL-1β in experimental autoimmune encephalomyelitis. Neurobiol Dis 2011; 43:669-77. [PMID: 21672630 DOI: 10.1016/j.nbd.2011.05.018] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 05/17/2011] [Accepted: 05/28/2011] [Indexed: 11/17/2022] Open
Abstract
Transient receptor potential vanilloid 1 (TRPV1) channels are involved in several inflammatory diseases. However, their action is still controversial, and both pro-inflammatory and anti-inflammatory roles have been described. We used a strain of TRPV1-KO mice to characterize the role of these channels in experimental autoimmune encephalomyelitis (EAE), which models multiple sclerosis (MS) in mice. EAE mice showed higher lethality in the peak phase of the disease and a better recovery of the surviving animals in the chronic stages, compared to their wild-type (WT) counterparts. By means of whole-cell patch clamp experiments in corticostriatal brain slices, we found that the absence of TRPV1 channels exacerbated the defect of glutamate transmission occurring in the peak phase of EAE, and attenuated the alterations of GABA synapses in the chronic phase of EAE, thus paralleling the dual effects of TRPV1-KO on the motor deficits of EAE mice. Furthermore, in slices from non-EAE mice, we found that genetic or pharmacological blockade of TRPV1 channels enhanced the synaptic effects of tumor necrosis factor α (TNF-α) on glutamate-mediated excitatory postsynaptic currents, and prevented the action of interleukin 1β (IL-1β) on GABAergic inhibitory postsynaptic currents. Together, our results suggest that TRPV1 channels contrast TNF-α-mediated synaptic deficits in the peak phase of EAE and, in the chronic stages, enhance IL-1β-induced GABAergic defects. The opposing interplay with the synaptic actions of the two major pro-inflammatory cytokines might explain the bimodal effects of TRPV1 ablation on the motor deficits of EAE, and suggests that the inflammatory milieu determines whether TRPV1 channels exert preferentially aversive or protective effects on neurons during neuroinflammatory diseases.
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Affiliation(s)
- Gabriele Musumeci
- Clinica Neurologica, Dipartimento di Neuroscienze, Università Tor Vergata, 00133 Rome, Italy
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128
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McDougall JJ. Peripheral analgesia: Hitting pain where it hurts. Biochim Biophys Acta Mol Basis Dis 2011; 1812:459-67. [DOI: 10.1016/j.bbadis.2010.12.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 12/09/2010] [Accepted: 12/15/2010] [Indexed: 10/18/2022]
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129
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Hypoxia-induced sensitization of transient receptor potential vanilloid 1 involves activation of hypoxia-inducible factor-1 alpha and PKC. Pain 2011; 152:936-945. [DOI: 10.1016/j.pain.2011.02.024] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 12/26/2010] [Accepted: 02/07/2011] [Indexed: 02/01/2023]
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130
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Rowbotham MC, Nothaft W, Duan RW, Wang Y, Faltynek C, McGaraughty S, Chu KL, Svensson P. Oral and cutaneous thermosensory profile of selective TRPV1 inhibition by ABT-102 in a randomized healthy volunteer trial. Pain 2011; 152:1192-1200. [PMID: 21377273 DOI: 10.1016/j.pain.2011.01.051] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 01/24/2011] [Accepted: 01/25/2011] [Indexed: 10/18/2022]
Abstract
The capsaicin receptor (TRPV1) antagonist ABT-102 demonstrates efficacy in multiple preclinical pain models. However, evolving clinical data for this compound class suggest potentially profound drug-induced thermosensory impairment. Safety and tolerability of ABT-102 were assessed in a multiple-dose, double-blind, placebo-controlled, randomized healthy volunteer trial. Thirty-six participants were randomized in a 2:1 ratio to ABT-102:placebo in 3 dose groups (1 mg, 2 mg, and 4 mg twice a day) and confined to an inpatient research unit for a 7-day treatment period and 3 follow-up days. Outcome measures included: oral and cutaneous cold detection, warm detection (WDT), and heat pain thresholds (HPT); oral perceived heat intensity (oral liquid test); time to hand withdrawal (water bath test); and cutaneous pain intensity (long thermal stimulus). Significant dose-dependent (placebo- and baseline-adjusted) increases in HPT and reduced painfulness of suprathreshold heat were present from days 1-7. For ABT-102 4 mg twice a day, model-based mean differences from placebo (95% confidence interval) were as follows: oral HPT, day 1=2.5°C (0.6-4.4), day 5=4.4°C (2.5-6.3); cutaneous HPT, day 2=3.3°C (1.4-5.3), day 5=5.3°C (3.3-7.2); oral WDT, day 1=2.6°C (0.5-4.7), day 5=2.7°C (0.6-4.9); cutaneous WDT, day 2=1.3 (0.0-2.6), day 5=1.6 (0.3-2.8) (all P<0.05). Oral liquid test and water bath test results followed a similar pattern. There was no effect on cutaneous cold detection. All effects were fully reversed by day 10. There were no other relevant safety findings. Core body temperature remained below 39°C in all participants. In conclusion, ABT-102 potently and reversibly increased HPT and reduced painfulness of suprathreshold oral/cutaneous heat.
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Affiliation(s)
- Michael C Rowbotham
- California Pacific Medical Center Research Institute, San Francisco, CA, USA Abbott Pain Care, Abbott Park, IL, USA Abbott Neuroscience and Pain Discovery, Abbott Park, IL, USA MINDLab, Center of Functionally Integrative Neuroscience, Aarhus University Hospital & Department of Clinical Oral Physiology, School of Dentistry, Aarhus University, Aarhus C, Denmark
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131
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[Types of topical treatment for peripheral neuropathic pain : Mechanism of action and indications]. Schmerz 2011; 24:317-25. [PMID: 20628765 DOI: 10.1007/s00482-010-0939-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The term "peripheral neuropathic pain syndromes" summarizes several chronic pain syndromes, which can occur focally or generalized in the peripheral nervous system in the course of an impairment of afferent neurons. Controlled clinical trials gave distinct indications for systemic treatments with antidepressants, anticonvulsants and opioid analgesics in several neuropathic pain syndromes. In addition to these systemic therapies, there are also two topical treatment options: topical application of lidocaine and capsaicin. An important cause of sensitization phenomena of afferent nociceptors is the upregulation of sodium channels and thermosensor channels. In the context of a partial nerve lesion that leaves behind partially preserved or regenerated afferent nerve fibres, just these channels could be used as target structures for topical medications. Topically applied drugs are absorbed systemically only in minute quantities, so systemic side effects are negligible. Pharmacological interactions with systematically acting substances are also virtually absent; thus, topically applied substances are especially appropriate for add-on therapy in addition to systemic pain medication.
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132
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Yejella RP, Atla SR. A Study of Anti-inflammatory and Analgesic Activity of New 2,4,6-Trisubstituted Pyrimidines. Chem Pharm Bull (Tokyo) 2011; 59:1079-82. [DOI: 10.1248/cpb.59.1079] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Rajendra Prasad Yejella
- Pharmaceutical Chemistry Division, University College of Pharmaceutical Sciences, Andhra University
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133
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TRPV1: A Therapy Target That Attracts the Pharmaceutical Interests. TRANSIENT RECEPTOR POTENTIAL CHANNELS 2011; 704:637-65. [DOI: 10.1007/978-94-007-0265-3_34] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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134
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Binshtok AM. Mechanisms of nociceptive transduction and transmission: a machinery for pain sensation and tools for selective analgesia. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011; 97:143-77. [PMID: 21708310 DOI: 10.1016/b978-0-12-385198-7.00006-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Many surgical and dental procedures depend on use of local anesthetics to reversibly eliminate pain. By the blockade of voltage-gated sodium channels, local anesthetics prevent the transmission of nociceptive information. However, since all local anesthetics act non-selectively on all types of axons they also cause a loss of innocuous sensation, motor paralysis and autonomic block. Thus, approaches that produce only a selective blockade of pain fibers are of great potential clinical importance. In this chapter we will review the recent findings describing mechanisms of pain transduction and transmission and introduce novel therapeutic approaches to produce pain-selective analgesia.
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Affiliation(s)
- Alexander M Binshtok
- Department of Medical Neurobiology, Institute for Medical Research Israel Canada and Center for Research on Pain, The Hebrew University Medical School, Jerusalem, Israel
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135
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Watabiki T, Kiso T, Tsukamoto M, Aoki T, Matsuoka N. Intrathecal Administration of AS1928370, a Transient Receptor Potential Vanilloid 1 Antagonist, Attenuates Mechanical Allodynia in a Mouse Model of Neuropathic Pain. Biol Pharm Bull 2011; 34:1105-8. [DOI: 10.1248/bpb.34.1105] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Tetsuo Kiso
- Pharmacology Research Labs., Astellas Pharma Inc
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136
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Watabiki T, Kiso T, Kuramochi T, Yonezawa K, Tsuji N, Kohara A, Kakimoto S, Aoki T, Matsuoka N. Amelioration of neuropathic pain by novel transient receptor potential vanilloid 1 antagonist AS1928370 in rats without hyperthermic effect. J Pharmacol Exp Ther 2010; 336:743-50. [PMID: 21098091 DOI: 10.1124/jpet.110.175570] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transient receptor potential vanilloid 1 (TRPV1) is activated by a variety of stimulations, such as endogenous ligands and low pH, and is believed to play a role in pain transmission. TRPV1 antagonists have been reported to be effective in several animal pain models; however, some compounds induce hyperthermia in animals and humans. We discovered the novel TRPV1 antagonist (R)-N-(1-methyl-2-oxo-1,2,3,4-tetrahydro-7-quinolyl)-2-[(2-methylpyrrolidin-1-yl)methyl]biphenyl-4-carboxamide (AS1928370) in our laboratory. AS1928370 bound to the resiniferatoxin-binding site on TRPV1 and inhibited capsaicin-mediated inward currents with an IC₅₀ value of 32.5 nM. Although AS1928370 inhibited the capsaicin-induced Ca²(+) flux in human and rat TRPV1-expressing cells, the inhibitory effect on proton-induced Ca²(+) flux was extremely small. In addition, AS1928370 showed no inhibitory effects on transient receptor potential vanilloid 4, transient receptor potential ankyrin 1, and transient receptor potential melastatin 8 in concentrations up to 10 μM. AS1928370 improved capsaicin-induced secondary hyperalgesia and mechanical allodynia in an L5/L6 spinal nerve ligation model in rats with respective ED₅₀ values of 0.17 and 0.26 mg/kg p.o. Furthermore, AS1928370 alleviated inflammatory pain in a complete Freund's adjuvant model at 10 mg/kg p.o. AS1928370 had no effect on rectal body temperature up to 10 mg/kg p.o., although a significant hypothermic effect was noted at 30 mg/kg p.o. In addition, AS1928370 showed no significant effect on motor coordination. These results suggest that blockage of the TRPV1 receptor without affecting the proton-mediated TRPV1 activation is a promising approach to treating neuropathic pain because of the potential wide safety margin against hyperthermic effects. As such, compounds such as ASP1928370 may have potential as new analgesic agents for treating neuropathic pain.
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Affiliation(s)
- Tomonari Watabiki
- Pain Research, Pharmacology Research Laboratories, Drug Discovery Research, Astellas Pharma Inc., Ibaraki, Japan.
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Palazzo E, Luongo L, de Novellis V, Berrino L, Rossi F, Maione S. Moving towards supraspinal TRPV1 receptors for chronic pain relief. Mol Pain 2010; 6:66. [PMID: 20937102 PMCID: PMC2959024 DOI: 10.1186/1744-8069-6-66] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 10/11/2010] [Indexed: 12/20/2022] Open
Abstract
Transient receptor potential vanilloid type 1 (TRPV1) receptor is a non selective ligand-gated cation channel activated by capsaicin, heat, protons and endogenous lipids termed endovanilloids. As well as peripheral primary afferent neurons and dorsal root ganglia, TRPV1 receptor is also expressed in spinal and supraspinal structures such as those belonging to the endogenous antinociceptive descending pathway which is a circuitry of the supraspinal central nervous system whose task is to counteract pain. It includes periaqueductal grey (PAG) and rostral ventromedial medulla (RVM) whose activation leads to analgesia. Such an effect is associated with a glutamate increase and the activation of OFF and inhibition of ON cell population in the rostral ventromedial medulla (RVM). Activation of the antinociceptive descending pathway via TPRV1 receptor stimulation in the PAG may be a novel strategy for producing analgesia in chronic pain. This review will summarize the more recent insights into the role of TRPV1 receptor within the antinociceptive descending pathway and its possible exploitation as a target for new pain-killer agents in chronic pain conditions, with particular emphasis on the most untreatable pain state: neuropathic pain.
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Affiliation(s)
- Enza Palazzo
- Department of Experimental Medicine, Pharmacology Division, The Second University of Naples, Naples, Italy.
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138
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Gong QJ, Li YY, Xin WJ, Wei XH, Cui Y, Wang J, Liu Y, Liu CC, Li YY, Liu XG. Differential effects of adenosine A1 receptor on pain-related behavior in normal and nerve-injured rats. Brain Res 2010; 1361:23-30. [PMID: 20850420 DOI: 10.1016/j.brainres.2010.09.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 09/08/2010] [Accepted: 09/08/2010] [Indexed: 11/16/2022]
Abstract
This study investigated the effects of N6-cyclopentyladenosine (CPA), a potent and selective adenosine A1 receptor (A1R) agonist in normal and nerve-injured rats and mechanisms of its action by behavioral tests and electrophysiological technique. The results showed: (1) In normal rats, intraperitoneal administration of CPA (1mg/kg) increased paw withdrawal latencies, in a way blocked by a selective A1R antagonist 8-cyclopentyl-1, 3-dipropylxanthine (DPCPX, 3mg/kg, i.p.), but had no influence on the threshold of mechanical stimulation. (2) In rats with neuropathic pain induced by spinal nerve ligation (SNL), CPA reduced thermal hyperalgesia and mechanical allodynia, which could last 6h and 10h, respectively (n=6/group, P<0.05). Both of the effects could be blocked by pretreatment of DPCPX intraperitoneally. (3) The baseline of C-fiber but not A-fiber evoked field potentials was depressed by spinal application of CPA (0.01 mM), and this effect was prevented by application of DPCPX (0.02 mM) 30 min before CPA. (4) Spinal application of CPA depressed long-term potentiation (LTP) of A- and C-fiber evoked field potentials, and both the depression could be blocked by pretreatment of DPCPX 30 min before CPA. These results suggested that the activation of A1R has different influences on normal and neuropathic rats probably due to the absence and presence of central sensitization in spinal dorsal horn.
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Affiliation(s)
- Qing-Juan Gong
- Department of Physiology and Pain Research Center, Zhongshan Medical School, Sun Yat-Sen University, 74 Zhongshan Rd 2, Guangzhou 510080, China
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139
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Corder G, Siegel A, Intondi AB, Zhang X, Zadina JE, Taylor BK. A novel method to quantify histochemical changes throughout the mediolateral axis of the substantia gelatinosa after spared nerve injury: characterization with TRPV1 and substance P. THE JOURNAL OF PAIN 2010; 11:388-98. [PMID: 20350706 DOI: 10.1016/j.jpain.2009.09.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 09/04/2009] [Accepted: 09/21/2009] [Indexed: 10/19/2022]
Abstract
UNLABELLED Nerve injury dramatically increases or decreases protein expression in the spinal cord dorsal horn. Whether the spatial distribution of these changes is restricted to the central innervation territories of injured nerves or could spread to adjacent territories in the dorsal horn is not understood. To address this question, we developed a simple computer software-assisted method to precisely distinguish and efficiently quantify immunohistochemical staining patterns across the mediolateral axis of the dorsal horn 2 weeks after transection of either the tibial and common peroneal nerves (thus sparing the sural branch, spared nerve injury, [SNI]), the tibial nerve, or the common peroneal and sural nerves. Using thiamine monophosphatase (TMP) histochemistry, we determined that central terminals of the tibial, common peroneal, sural, and posterior cutaneous nerves occupy the medial 35%, medial-central 20%, central-lateral 20%, and lateral 25% of the substantia gelatinosa, respectively. We then used these calculations to show that SNI reduced the expression of SP and TRPV1 immunoreactivity within the tibial and peroneal innervation territories in the L4 dorsal horn, without changing expression in the uninjured, sural sector. We conclude that SNI-induced loss of SP and TRPV1 in central terminals of dorsal horn is restricted to injured fibers. Our new method enables direct comparison of injured and uninjured terminals in the dorsal horn so as to better understand their relative contributions to mechanisms of chronic pain. PERSPECTIVE A simple computer software-assisted algorithm was developed to precisely distinguish and efficiently quantify immunohistochemical staining patterns across the mediolateral axis of the dorsal horn after distal sciatic-branch transection. This method will facilitate a better understanding of the relative contribution of injured and uninjured terminals to mechanisms of chronic pain.
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Affiliation(s)
- Gregory Corder
- Department of Physiology, School of Medicine, University of Kentucky Medical Center, Lexington, KY 40536-0298, USA
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140
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Premkumar LS, Sikand P. TRPV1: a target for next generation analgesics. Curr Neuropharmacol 2010; 6:151-63. [PMID: 19305794 PMCID: PMC2647151 DOI: 10.2174/157015908784533888] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 10/17/2007] [Accepted: 11/11/2007] [Indexed: 12/11/2022] Open
Abstract
Transient Receptor Potential Vanilloid 1 (TRPV1) is a Ca2+ permeant non-selective cation channel expressed in a subpopulation of primary afferent neurons. TRPV1 is activated by physical and chemical stimuli. It is critical for the detection of nociceptive and thermal inflammatory pain as revealed by the deletion of the TRPV1 gene. TRPV1 is distributed in the peripheral and central terminals of the sensory neurons and plays a role in initiating action potentials at the nerve terminals and modulating neurotransmitter release at the first sensory synapse, respectively. Distribution of TRPV1 in the nerve terminals innervating blood vessels and in parts of the CNS that are not subjected to temperature range that is required to activate TRPV1 suggests a role beyond a noxious thermal sensor. Presently, TRPV1 is being considered as a target for analgesics through evaluation of different antagonists. Here, we will discuss the distribution and the functions of TRPV1, potential use of its agonists and antagonists as analgesics and highlight the functions that are not related to nociceptive transmission that might lead to adverse effects.
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Affiliation(s)
- Louis S Premkumar
- Department of Pharmacology, Southern Illinois University School of Medicine Springfield, IL 62702, USA.
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141
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Story GM. The emerging role of TRP channels in mechanisms of temperature and pain sensation. Curr Neuropharmacol 2010; 4:183-96. [PMID: 18615141 DOI: 10.2174/157015906778019482] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Accepted: 05/17/2006] [Indexed: 01/13/2023] Open
Abstract
Pain is universal and vital to survival. It is an essential component of our sense of touch; together, touch and pain have evolved to enable our awareness of the intricacies of our environment and to warn us of danger and possible injury. There is a clear link between temperature sensation and pain-painful temperature sensations occur acutely and are a hallmark of inflammatory and chronic pain disorders of the nervous system. Mounting evidence suggests a subset of Transient Receptor Potential (TRP) ion channels activated by temperature (thermoTRPs) are important molecular players in acute, inflammatory and chronic pain states. Varying degrees of heat activate four of these channels (TRPV1-4), while cooling temperatures ranging from pleasant to painful activate two distantly related thermoTRP channels (TRPM8 and TRPA1). ThermoTRP channels are also chemosensitive, being activated and or modulated by plant-derived small molecules and endogenous inflammatory mediators. All thermoTRPs are expressed in tissues essential to cutaneous thermal and pain sensation. This review examines the contribution of thermoTRP channels to our understanding of temperature and pain transduction at the molecular level.
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Affiliation(s)
- Gina M Story
- Washington University Pain Center, Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8054, St. Louis, MO 63110, USA.
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Mammalian target of rapamycin signaling in the spinal cord is required for neuronal plasticity and behavioral hypersensitivity associated with neuropathy in the rat. THE JOURNAL OF PAIN 2010; 11:1356-67. [PMID: 20452291 PMCID: PMC3000494 DOI: 10.1016/j.jpain.2010.03.013] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 03/04/2010] [Accepted: 03/16/2010] [Indexed: 01/13/2023]
Abstract
The protein kinase mammalian target of rapamycin (mTOR) regulates mRNA translation and is inhibited by rapamycin. Signaling pathways involving mTOR are implicated in physiological and pathophysiological processes. We determined the spinal effects of the rapamycin analogue cell cycle inhibitor (CCI)-779 on neuronal responses and behavioral hypersensitivity in a model of persistent neuropathic pain. We also assessed the anatomical distribution of spinal mTOR signaling pathways. Specifically, we ligated rat spinal nerves L5 and L6 to produce a model of neuropathic pain. After confirming neuropathy with behavioral testing, we obtained in vivo single-unit extracellular stimulus-evoked recordings from deep dorsal horn spinal neurons. We applied CCI-779 spinally in electrophysiological and behavioral studies and assessed its effects accordingly. We also used immunohistochemistry to probe for mTOR signaling pathways in dorsal root ganglia (DRG) and the spinal cord. We found that spinally administered CCI-779 rapidly attenuated calibrated mechanically but not thermally evoked neuronal responses and mechanically evoked behavioral responses. Immunohistochemistry showed presence of mTOR signaling pathways in nociceptive-specific C-fiber DRG and in neurons of inner lamina II of the spinal cord. We conclude that alterations in the activity of spinal mTOR signaling pathways are crucial to the full establishment of spinal neuronal plasticity and behavioral hypersensitivity associated with nerve injury. Perspective This study is consistent with growing evidence implicating mTOR signaling pathways as important modulators of persistent pain, providing novel insights into the molecular mechanisms of pain maintenance and potential for novel approaches into treating chronic pain.
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143
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Hori K, Ozaki N, Suzuki S, Sugiura Y. Upregulations of P2X3 and ASIC3 involve in hyperalgesia induced by cisplatin administration in rats. Pain 2010; 149:393-405. [DOI: 10.1016/j.pain.2010.03.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 02/03/2010] [Accepted: 03/05/2010] [Indexed: 11/25/2022]
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Abstract
Neuropathic pain, a severe chronic pain condition characterized by a complex pathophysiology, is a largely unmet medical need. Ion channels, which underlie cell excitability, are heavily implicated in the biological mechanisms that generate and sustain neuropathic pain. This review highlights the biological evidence supporting the involvement of voltage-, proton- and ligand-gated ion channels in the neuropathic pain setting. Ion channel modulators at different research or development stages are reviewed and referenced. Ion channel modulation is one of the main avenues to achieve novel, improved neuropathic pain treatments. Voltage-gated sodium and calcium channel and glutamate receptor modulators are likely to produce new, improved agents in the future. Rationally targeting subtypes of known ion channels, tackling recently discovered ion channel targets or combining drugs with different mechanism of action will be primary sources of new drugs in the longer term.
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145
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Ta LE, Bieber AJ, Carlton SM, Loprinzi CL, Low PA, Windebank AJ. Transient Receptor Potential Vanilloid 1 is essential for cisplatin-induced heat hyperalgesia in mice. Mol Pain 2010; 6:15. [PMID: 20205720 PMCID: PMC2848188 DOI: 10.1186/1744-8069-6-15] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Accepted: 03/05/2010] [Indexed: 12/16/2022] Open
Abstract
Background Cisplatin is primarily used for treatment of ovarian and testicular cancer. Oxaliplatin is the only effective treatment for metastatic colorectal cancer. Both are known to cause dose related, cumulative toxic effects on the peripheral nervous system and thirty to forty percent of cancer patients receiving these agents experience painful peripheral neuropathy. The mechanisms underlying painful platinum-induced neuropathy remain poorly understood. Previous studies have demonstrated important roles for TRPV1, TRPM8, and TRPA1 in inflammation and nerve injury induced pain. Results In this study, using real-time, reverse transcriptase, polymerase chain reaction (RT-PCR), we analyzed the expression of TRPV1, TRPM8, and TRPA1 induced by cisplatin or oxaliplatin in vitro and in vivo. For in vitro studies, cultured E15 rat dorsal root ganglion (DRG) neurons were treated for up to 48 hours with cisplatin or oxaliplatin. For in vivo studies, trigeminal ganglia (TG) were isolated from mice treated with platinum drugs for three weeks. We show that cisplatin and oxaliplatin-treated DRG neurons had significantly increased in TRPV1, TRPA1, and TRPM8 mRNA expression. TG neurons from cisplatin treated mice had significant increases in TRPV1 and TRPA1 mRNA expression while oxaliplatin strongly induced only TRPA1. Furthermore, compared to the cisplatin-treated wild-type mice, cisplatin-treated TRPV1-null mice developed mechanical allodynia but did not exhibit enhancement of noxious heat- evoked pain responses. Immunohistochemistry studies showed that cisplatin-treated mice had no change in the proportion of the TRPV1 immunopositive TG neurons. Conclusion These results indicate that TRPV1 and TRPA1 could contribute to the development of thermal hyperalgesia and mechanical allodynia following cisplatin-induced painful neuropathy but that TRPV1 has a crucial role in cisplatin-induced thermal hyperalgesia in vivo.
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Affiliation(s)
- Lauren E Ta
- Program in Molecular Neuroscience, Mayo Graduate School, Mayo Clinic, College of Medicine, Rochester, MN 55905, USA.
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146
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Yamamoto W, Sugiura A, Nakazato-Imasato E, Kita Y. Characterization of primary sensory neurons mediating static and dynamic allodynia in rat chronic constriction injury model. J Pharm Pharmacol 2010; 60:717-22. [DOI: 10.1211/jpp.60.6.0006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Mechanical allodynia, such as static and dynamic allodynia, is a prominent feature of neuropathic pain syndromes. The aim of this study is to characterize primary sensory neurons mediating the mechanical allodynia in a rat chronic constriction injury (CCI) model with a combination of pharmacological and histological investigations. N-(4-Tertiarybutylphenyl)-4-(3-chloropyridin-2-yl) tetrahydropyrazine-1(2H)-carbox-amide (BCTC), a selective and competitive antagonist of the vanilloid receptor 1 (TRPV1), and resiniferatoxin, which causes desensitization of TRPV1-expressing fibres, suppressed static allodynia but not dynamic allodynia in CCI rats. Immunohistochemical studies of TRPV1 and NF200, an A-fibre marker 200 kDa neurofilament, in dorsal root ganglion neurons demonstrated that each 48% of the positive-stained neurons were immunoreactive only for TRPV1 or NF200. The other 4% of stained neurons were double-positive for TRPV1 and NF200. Of the TRPV1-positive neurons, more than 99% were small- (diameter <25 μm) and medium- (25–45 μm) sized. In contrast, 97% of NF200 single-labelled neurons were medium- and large- (>45 μm) sized. These findings suggest that two types of mechanical allodynia are transmitted by different primary sensory neurons: static allodynia is mediated by TRPV1 positive small- and medium-sized neurons and dynamic allodynia might be signalled by TRPV1-negative medium- and large-sized neurons.
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Affiliation(s)
- Wataru Yamamoto
- Discovery Biology Research, Nagoya Laboratories, Pfizer Global Research and Development, Pfizer Inc., 5-2, Taketoyo, Aichi, 470-2393, Japan
| | - Akemi Sugiura
- Discovery Biology Research, Nagoya Laboratories, Pfizer Global Research and Development, Pfizer Inc., 5-2, Taketoyo, Aichi, 470-2393, Japan
| | - Etsuko Nakazato-Imasato
- Discovery Biology Research, Nagoya Laboratories, Pfizer Global Research and Development, Pfizer Inc., 5-2, Taketoyo, Aichi, 470-2393, Japan
| | - Yasuhiro Kita
- Discovery Biology Research, Nagoya Laboratories, Pfizer Global Research and Development, Pfizer Inc., 5-2, Taketoyo, Aichi, 470-2393, Japan
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Vilceanu D, Honore P, Hogan QH, Stucky CL. Spinal nerve ligation in mouse upregulates TRPV1 heat function in injured IB4-positive nociceptors. THE JOURNAL OF PAIN 2009; 11:588-99. [PMID: 20015699 DOI: 10.1016/j.jpain.2009.09.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 09/23/2009] [Accepted: 09/29/2009] [Indexed: 01/14/2023]
Abstract
UNLABELLED Peripheral nerve injury leads to neuropathic pain, but the underlying mechanisms are not clear. The TRPV1 channel expressed by nociceptors is one receptor for noxious heat and inflammatory molecules. Lumbar 4 (L4) spinal nerve ligation (SNL) in mice induced persistent heat hyperalgesia 4 to 10 days after injury. The heat hypersensitivity was completely reversed by the TRPV1 antagonist A-425619. Furthermore, DRG neurons were isolated from the injured L4 ganglia or adjacent L3 ganglia 4 to 10 days after L4 SNL. Whole-cell patch-clamp recordings were performed and heat stimuli (22 degrees C to 50 degrees C/3 s) were applied to the soma. Neurons were classified by soma size and isolectin-B4 (IB4) binding. Among directly injured L4 neurons, SNL increased the percentage of small-diameter IB4-positive neurons that were heat-sensitive from 13% (naive controls) to 56% and conversely decreased the proportion of small IB4-negative neurons that were heat-sensitive from 66% (naive controls) to 34%. There was no change in IB4 binding in neurons from the injured ganglia. Surprisingly, in neurons from the adjacent L3 ganglia, SNL had no effect on the heat responsiveness of either IB4-positive or negative small neurons. Also, SNL had no effect on heat responses in medium-large-diameter neurons from either the injured or adjacent ganglia. PERSPECTIVE TRPV1 function is upregulated in IB4-positive sensory neurons, and TRPV1 is responsible for the behavioral heat hypersensitivity in the spinal nerve ligation model. Because IB4-positive neurons may contribute to the emotional perception of pain, TRPV1 antagonists, targeting both sensory and affective pain components, could have broad analgesic effects.
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Affiliation(s)
- Daniel Vilceanu
- Department of Cell Biology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226-0509, USA
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148
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Effect of resiniferatoxin on glutamatergic spontaneous excitatory synaptic transmission in substantia gelatinosa neurons of the adult rat spinal cord. Neuroscience 2009; 164:1833-44. [DOI: 10.1016/j.neuroscience.2009.09.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 08/25/2009] [Accepted: 09/15/2009] [Indexed: 11/17/2022]
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149
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Alawi K, Keeble J. The paradoxical role of the transient receptor potential vanilloid 1 receptor in inflammation. Pharmacol Ther 2009; 125:181-95. [PMID: 19896501 DOI: 10.1016/j.pharmthera.2009.10.005] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Accepted: 10/09/2009] [Indexed: 12/19/2022]
Abstract
The transient potential receptor vanilloid 1 (TRPV1) receptor is a non-selective cation channel that is chemically activated by capsaicin, the pungent component of hot peppers. In addition, endogenous compounds, in particular the endogenous cannabinoid receptor activator, anandamide, have been demonstrated to activate TRPV1 in vivo. TRPV1 receptors are also activated by temperatures within the noxious range (>43 degrees C) and low pH (<pH 6.0). TRPV1 receptors are predominantly expressed in primary afferent fibres which are peptidergic sensory neurones, such as the thinly myelinated A-delta and unmyelinated C-fibres. TRPV1 receptors have also been demonstrated to be present in non-neuronal cells. Historically, TRPV1 has been considered as a pro-inflammatory receptor due to its key role in several conditions, including neuropathic pain, joint inflammation and inflammatory bowel disease, amongst others. However, the purpose of this review is to underline the emerging new evidence which demonstrate paradoxical, protective functions for this unique receptor in vivo. For example, in experimentally induced sepsis, TRPV1 null mice demonstrated elevated levels of pathological markers in comparison to wild-type mice. In addition to the pro-inflammatory and protective roles of TRPV1 in pathophysiological states, TRPV1 has also been shown to have important functions under normal physiological conditions, for example in urinary bladder function, thermoregulation and neurogenesis. The emerging functions of TRPV1 highlight the necessity for further research in light of increasing reports of potential TRPV1 antagonists undergoing pre-clinical experimentations.
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Affiliation(s)
- Khadija Alawi
- Pharmaceutical Science Research Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE19NH, United Kingdom
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150
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Bordet T, Pruss RM. Targeting neuroprotection as an alternative approach to preventing and treating neuropathic pain. Neurotherapeutics 2009; 6:648-62. [PMID: 19789070 PMCID: PMC5084287 DOI: 10.1016/j.nurt.2009.07.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Accepted: 07/08/2009] [Indexed: 11/29/2022] Open
Abstract
Neuropathic pain syndromes arise from dysfunction of the nerve itself, through traumatic or nontraumatic injury. Unlike acute pain syndromes, the pain is long-lasting and does not respond to common analgesic therapies. Drugs that disrupt nerve conduction and transmission or central sensitization, currently the only effective treatments, are only modestly effective for a portion of the patients suffering from neuropathic pain and come with the cost of serious adverse effects. Neurodegeneration, as a reaction to nerve trauma or chronic metabolic or chemical intoxication, appears to be an underlying cause of neuropathic pain. Identifying mechanisms of neurodegeneration and designing neuroprotective therapies is an ambitious goal toward treating or even preventing the development of these disabling disorders.
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Affiliation(s)
- Thierry Bordet
- Trophos, Parc Scientifique de Luminy, Luminy Biotech Entreprises, Case 931, 13288 Marseille Cedex 9, France
| | - Rebecca M. Pruss
- Trophos, Parc Scientifique de Luminy, Luminy Biotech Entreprises, Case 931, 13288 Marseille Cedex 9, France
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