1
|
The Role of Thermosensitive Ion Channels in Mammalian Thermoregulation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:355-370. [DOI: 10.1007/978-981-16-4254-8_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
2
|
Deftu AT, Ciorescu R, Gheorghe RO, Mihăilescu D, Ristoiu V. CXCL1 and CXCL2 Inhibit the Axon Outgrowth in a Time- and Cell-Type-Dependent Manner in Adult Rat Dorsal Root Ganglia Neurons. Neurochem Res 2019; 44:2215-2229. [PMID: 31422522 DOI: 10.1007/s11064-019-02861-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 08/07/2019] [Accepted: 08/12/2019] [Indexed: 12/12/2022]
Abstract
The ability to regrow their axons after an injury is a hallmark of neurons in peripheral nervous system which distinguish them from central nervous system neurons. This ability is influenced by their intrinsic capacity to regrow and by the extracellular environment which needs to be supportive of regrowth. CXCL1 [Chemokine (C-X-C motif) Ligand 1] and CXCL2 [Chemokine (C-X-C motif) Ligand 2] are two low-molecular-weight chemokines which can influence neuronal proliferation, differentiation and neurogenesis, but which are also upregulated by injury or inflammation. In this study we investigated the effects of long-term incubation (24, 48 and 72 h) with different concentrations of CXCL1 (0.4, 4 or 40 nM) or CXCL2 (0.36, 3.6 or 36 nM) on the axon outgrowth of adult rat dorsal root ganglia neurons in culture. The results showed that both chemokines significantly inhibited the axon outgrowth, with large and medium NF200 (NeuroFilament 200) (+) dorsal root ganglia neurons affected quicker, compared to small IB4 (Isolectin B4) (+) dorsal root ganglia neurons which were affected after longer exposure. Blocking CXCR2 (C-X-C motif chemokine receptor 2) which mediates the effects of CXCL1 and CXCL2 prevented these effects, suggesting that CXCR2 may represent a new therapeutic target for promoting the axon outgrowth after a peripheral nerve injury.
Collapse
Affiliation(s)
- Antonia Teona Deftu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania
| | - Ruxandra Ciorescu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania
| | - Roxana-Olimpia Gheorghe
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania
| | - Dan Mihăilescu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania
| | - Violeta Ristoiu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania.
| |
Collapse
|
3
|
Xing J, Li J. The Role Played by Adenosine in Modulating Reflex Sympathetic and Pressor Responses Evoked by Stimulation of TRPV1 in Muscle Afferents. Cell Physiol Biochem 2016; 40:39-48. [PMID: 27842306 DOI: 10.1159/000452523] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Activation of metabolite-sensitive transient receptor potential vanilloid type 1 (TRPV1) receptors (capsaicin receptors) in afferent nerves of the hindlimb muscles of rats increases renal sympathetic nerve activity (RSNA) and blood pressure (BP) via a reflex mechanism. The purpose of this study was to examine the role of adenosine in modulating the reflex RSNA and BP responses to stimulation of TRPV1. METHODS RSNA and BP responses were recorded in rats. Immunofluorescence and patch-clamp methods were employed to examine the receptor mechanisms responsible for the effects of adenosine. RESULTS Adenosine, in the concentration of 100 µM, injected into the femoral artery had an inhibitory effect on the reflex RSNA and BP responses induced by capsaicin. Likewise, arterial injection of adenosine analogue CGS21680 (A2A subtype receptor agonist, 10 µM and100 µM) also attenuated the reflex responses. In addition, co-existence of A2A and TRPV1 was observed in the dorsal root ganglion neurons. The prior application of adenosine or CGS21680 inhibited the magnitude of capsaicin-induced currents in muscle sensory neurons. CONCLUSION Adenosine contributes to muscle afferent TRPV1-engaged reflex sympathetic and pressor responses. It is likely that TRPV1 response is impaired as the levels of adenosine are increased in the hindlimb muscles under diseased conditions.
Collapse
Affiliation(s)
- Jihong Xing
- Jilin University First Hospital, Norman Bethune College of Medicine Changchun, Jilin, China
| | | |
Collapse
|
4
|
Kestell GR, Anderson RL, Clarke JN, Haberberger RV, Gibbins IL. Primary afferent neurons containing calcitonin gene-related peptide but not substance P in forepaw skin, dorsal root ganglia, and spinal cord of mice. J Comp Neurol 2015; 523:2555-69. [PMID: 26010480 DOI: 10.1002/cne.23804] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 04/20/2015] [Accepted: 04/29/2015] [Indexed: 12/11/2022]
Abstract
In mice dorsal root ganglia (DRG), some neurons express calcitonin gene-related peptide (CGRP) without substance P (SP; CGRP(+) SP(-) ). The projections and functions of these neurons are unknown. Therefore, we combined in vitro axonal tracing with multiple-labeling immunohistochemistry to neurochemically define these neurons and characterize their peripheral and central projections. Cervical spinal cord, DRG, and forepaw skin were removed from C57Bl/6 mice and multiple-labeled for CGRP, SP, and either marker for the sensory neuron subpopulations transient receptor potential vanilloid type 1 (TRPV1), neurofilament 200 (NF200), or vesicular glutamate transporter 2 (VGluT1). To determine central projections of CGRP(+) SP(-) neurons, Neurobiotin (NB) was applied to the C7 ventral ramus and visualized in DRG and spinal cord sections colabeled for CGRP and SP. Half (50%) of the CGRP-immunoreactive DRG neurons lacked detectable SP and had a mean soma size of 473 ± 14 μm(2) (n = 5); 89% of the CGRP(+) SP(-) neurons expressed NF200 (n = 5), but only 32% expressed TRPV1 (n = 5). Cutaneous CGRP(+) SP(-) fibers were numerous within dermal papillae and around hair shafts (n = 4). CGRP(+) SP(-) boutons were prevalent in lateral lamina I and in lamina IV/V of the dorsal horn (n = 5). NB predominantly labeled fibers penetrating lamina IV/V, 6 ± 3% contained CGRP (n = 5), and 21 ± 2% contained VGluT1 (n = 3). CGRP(+) SP(-) afferent neurons are likely to be non-nociceptive. Their soma size, neurochemical profile, and peripheral and central targets suggest that CGRP(+) SP(-) neurons are polymodal mechanoceptors.
Collapse
Affiliation(s)
- Garreth R Kestell
- Department of Anatomy and Histology, and Centre for Neuroscience, Flinders University, Adelaide, South Australia, 5001, Australia
| | - Rebecca L Anderson
- Department of Anatomy and Histology, and Centre for Neuroscience, Flinders University, Adelaide, South Australia, 5001, Australia
| | - Jennifer N Clarke
- Department of Anatomy and Histology, and Centre for Neuroscience, Flinders University, Adelaide, South Australia, 5001, Australia
| | - Rainer V Haberberger
- Department of Anatomy and Histology, and Centre for Neuroscience, Flinders University, Adelaide, South Australia, 5001, Australia
| | - Ian L Gibbins
- Department of Anatomy and Histology, and Centre for Neuroscience, Flinders University, Adelaide, South Australia, 5001, Australia
| |
Collapse
|
5
|
Yoo S, Lim JY, Hwang SW. Sensory TRP channel interactions with endogenous lipids and their biological outcomes. Molecules 2014; 19:4708-44. [PMID: 24739932 PMCID: PMC6271031 DOI: 10.3390/molecules19044708] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 04/08/2014] [Accepted: 04/08/2014] [Indexed: 01/30/2023] Open
Abstract
Lipids have long been studied as constituents of the cellular architecture and energy stores in the body. Evidence is now rapidly growing that particular lipid species are also important for molecular and cellular signaling. Here we review the current information on interactions between lipids and transient receptor potential (TRP) ion channels in nociceptive sensory afferents that mediate pain signaling. Sensory neuronal TRP channels play a crucial role in the detection of a variety of external and internal changes, particularly with damaging or pain-eliciting potentials that include noxiously high or low temperatures, stretching, and harmful substances. In addition, recent findings suggest that TRPs also contribute to altering synaptic plasticity that deteriorates chronic pain states. In both of these processes, specific lipids are often generated and have been found to strongly modulate TRP activities, resulting primarily in pain exacerbation. This review summarizes three standpoints viewing those lipid functions for TRP modulations as second messengers, intercellular transmitters, or bilayer building blocks. Based on these hypotheses, we discuss perspectives that account for how the TRP-lipid interaction contributes to the peripheral pain mechanism. Still a number of blurred aspects remain to be examined, which will be answered by future efforts and may help to better control pain states.
Collapse
Affiliation(s)
- Sungjae Yoo
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul 136-705, Korea.
| | - Ji Yeon Lim
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul 136-705, Korea.
| | - Sun Wook Hwang
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul 136-705, Korea.
| |
Collapse
|
6
|
Kim MJ, Lee SY, Yang KY, Nam SH, Kim HJ, Kim YJ, Bae YC, Ahn DK. Differential regulation of peripheral IL-1β-induced mechanical allodynia and thermal hyperalgesia in rats. Pain 2014; 155:723-732. [PMID: 24406203 DOI: 10.1016/j.pain.2013.12.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 12/18/2013] [Accepted: 12/30/2013] [Indexed: 11/29/2022]
Abstract
This study examined the differential mechanisms of mechanical allodynia and thermal hyperalgesia after injection of interleukin (IL) 1β into the orofacial area of male Sprague-Dawley rats. The subcutaneous administration of IL-1β produced both mechanical allodynia and thermal hyperalgesia. Although a pretreatment with iodoresiniferatoxin (IRTX), a transient receptor potential vanilloid 1 (TRPV1) antagonist, did not affect IL-1β-induced mechanical allodynia, it significantly abolished IL-1β-induced thermal hyperalgesia. On the other hand, a pretreatment with D-AP5, an N-methyl-d-aspartate (NMDA) receptor antagonist, and NBQX, an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, blocked IL-1β-induced mechanical allodynia. Pretreatment with H89, a protein kinase A (PKA) inhibitor, blocked IL-1β-induced mechanical allodynia but not thermal hyperalgesia. In contrast, pretreatment with chelerythrine, a protein kinase C (PKC) inhibitor, inhibited IL-1β-induced thermal hyperalgesia. Subcutaneous injections of 2% lidocaine, a local anesthetic agent, blocked IL-1β-induced thermal hyperalgesia but not IL-1β-induced mechanical allodynia. In the resiniferatoxin (RTX)-pretreated rats, a subcutaneous injection of IL-1β did not produce thermal hyperalgesia due to the depletion of TRPV1 in the primary afferent fibers. Double immunofluorescence revealed the colocalization of PKA with neurofilament 200 (NF200) and of PKC with the calcitonin gene-related peptide (CGRP) in the trigeminal ganglion. Furthermore, NMDA receptor 1 (NR1) and TRPV1 predominantly colocalize with PKA and PKC, respectively, in the trigeminal ganglion. These results suggest that IL-1β-induced mechanical allodynia is mediated by sensitized peripheral NMDA/AMPA receptors through PKA-mediated signaling in the large-diameter primary afferent nerve fibers, whereas IL-1β-induced thermal hyperalgesia is mediated by sensitized peripheral TRPV1 receptors through PKC-mediated signaling in the small-diameter primary afferent nerve fibers.
Collapse
Affiliation(s)
- Min J Kim
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea Department of Pediatric Dentistry, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea Department of Oral Anatomy, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Li J, Xing J, Lu J. Nerve Growth Factor, Muscle Afferent Receptors and Autonomic Responsiveness with Femoral Artery Occlusion. JOURNAL OF MODERN PHYSIOLOGICAL RESEARCH 2014; 1:1-18. [PMID: 25346945 PMCID: PMC4207086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The exercise pressor reflex is a neural control mechanism responsible for the cardiovascular responses to exercise. As exercise is initiated, thin fiber muscle afferent nerves are activated by mechanical and metabolic stimuli arising in the contracting muscles. This leads to reflex increases in arterial blood pressure and heart rate primarily through activation of sympathetic nerve activity (SNA). Studies of humans and animals have indicated that the exercise pressor reflex is exaggerated in a number of cardiovascular diseases. For the last several years, a series of studies have employed a rodent model to examine the mechanisms at receptor and cellular levels by which responses of SNA and blood pressure to static exercise are heightened in peripheral artery disease (PAD), one of the most common cardiovascular disorders. Specifically, femoral artery occlusion is used to study intermittent claudication that is observed in human PAD. Our studies have demonstrated that the receptors on thin fiber muscle afferents including transient receptor potential vanilloid type 1 (TRPV1), purinergic P2X3 and acid sensing ion channel subtype 3 (ASIC3) are engaged in augmented autonomic responses this disease. This review will present some of recent results in regard with several receptors in muscle sensory neurons in contribution to augmented autonomic responses in PAD. We will emphasize the role played by nerve growth factor (NGF) in regulating those sensory receptors in the processing of amplified exercise pressor reflex. Also, we will discuss the role played by hypoxia-inducible facor-1α regarding the enhanced autonomic reflex with femoral artery occlusion. The purpose of this review is to focus on a theme namely that PAD accentuates reflexively autonomic responses to exercise and further address regulatory mechanisms leading to abnormal autonomic responsiveness.
Collapse
Affiliation(s)
- Jianhua Li
- Heart & Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Jihong Xing
- Heart & Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Jian Lu
- Heart & Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| |
Collapse
|
8
|
Abstract
Transient receptor potential vanilloid type 2, TRPV2, is a calcium-permeable cation channel belonging to the TRPV channel family. This channel is activated by heat (>52 °C), various ligands, and mechanical stresses. In most of the cells, a large portion of TRPV2 is located in the endoplasmic reticulum under unstimulated conditions. Upon stimulation of the cells with phosphatidylinositol 3-kinase-activating ligands, TRPV2 is translocated to the plasma membrane and functions as a cation channel. Mechanical stress may also induce translocation of TRPV2 to the plasma membrane. The expression of TRPV2 is high in some types of cells including neurons, neuroendocrine cells, immune cells involved in innate immunity, and certain types of cancer cells. TRPV2 may modulate various cellular functions in these cells.
Collapse
Affiliation(s)
- Itaru Kojima
- Department of Cell Biology, Institute for Molecular & Cellular Regulation, Gunma University, Maebashi, Gunma Prefecture, 371-8511, Japan,
| | | |
Collapse
|
9
|
Perálvarez-Marín A, Doñate-Macian P, Gaudet R. What do we know about the transient receptor potential vanilloid 2 (TRPV2) ion channel? FEBS J 2013; 280:5471-87. [PMID: 23615321 DOI: 10.1111/febs.12302] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Revised: 03/22/2013] [Accepted: 04/14/2013] [Indexed: 12/30/2022]
Abstract
Transient receptor potential (TRP) ion channels are emerging as a new set of membrane proteins involved in a vast array of cellular processes and regulated by a large number of physical and chemical stimuli, which involves them with sensory cell physiology. The vanilloid TRP subfamily (TRPV) named after the vanilloid receptor 1 (TRPV1) consists of six members, and at least four of them (TRPV1-TRPV4) have been related to thermal sensation. One of the least characterized members of the TRP subfamily is TRPV2. Although initially characterized as a noxious heat sensor, TRPV2 now seems to have little to do with temperature sensing but a much more complex physiological profile. Here we review the available information and research progress on the structure, physiology and pharmacology of TRPV2 in an attempt to shed some light on the physiological and pharmacological deorphanization of TRPV2.
Collapse
Affiliation(s)
- Alex Perálvarez-Marín
- Centre d'Estudis en Biofísica, Departament de Bioquímica i de Biologia Molecular, Universitat Autònoma de Barcelona, Cerdanyola del Vallés, Spain
| | | | | |
Collapse
|
10
|
Li J, Xing J. Muscle afferent receptors engaged in augmented sympathetic responsiveness in peripheral artery disease. Front Physiol 2012; 3:247. [PMID: 22934005 PMCID: PMC3429025 DOI: 10.3389/fphys.2012.00247] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 06/17/2012] [Indexed: 01/23/2023] Open
Abstract
The exercise pressor reflex (EPR) is a neural control mechanism responsible for the cardiovascular responses to exercise. As exercise is initiated, thin fiber muscle afferent nerves are activated by mechanical and metabolic stimuli arising in the contracting muscles. This leads to reflex increases in arterial blood pressure (BP) and heart rate primarily through activation of sympathetic nerve activity (SNA). Studies of humans and animals have indicated that the EPR is exaggerated in a number of cardiovascular diseases. For the last several years, studies have specifically employed a rodent model to examine the mechanisms at receptor and cellular levels by which responses of SNA and BP to static exercise are heightened in peripheral artery disease (PAD), one of the most common cardiovascular disorders. A rat model of this disease has well been established. Specifically, femoral artery occlusion is used to study intermittent claudication that is observed in human PAD. The receptors on thin fiber muscle afferents that are engaged in this disease include transient receptor potential vanilloid type 1 (TRPV1), purinergic P2X, and acid sensing ion channel (ASIC). The role played by nerve growth factor in regulating those sensory receptors in the processing of amplified EPR was also investigated. The purpose of this review is to focus on a theme namely that PAD accentuates autonomic reflex responses to exercise and further address regulatory mechanisms leading to abnormal sympathetic responsiveness. This review will present some of recent results in regard with several receptors in muscle sensory neurons in contribution to augmented autonomic reflex responses in PAD. Review of the findings from recent studies would lead to a better understanding in integrated processing of sympathetic nervous system in PAD.
Collapse
Affiliation(s)
- Jianhua Li
- Heart and Vascular Institute, Penn State University College of Medicine Hershey, PA, USA
| | | |
Collapse
|
11
|
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.
Collapse
Affiliation(s)
- Jun Wang
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Medicine, Shaanxi, China
| | | | | | | | | | | | | |
Collapse
|
12
|
Panneton WM, Gan Q, Livergood RS. A trigeminoreticular pathway: implications in pain. PLoS One 2011; 6:e24499. [PMID: 21957454 PMCID: PMC3177822 DOI: 10.1371/journal.pone.0024499] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 08/11/2011] [Indexed: 01/18/2023] Open
Abstract
Neurons in the caudalmost ventrolateral medulla (cmVLM) respond to noxious stimulation. We previously have shown most efferent projections from this locus project to areas implicated either in the processing or modulation of pain. Here we show the cmVLM of the rat receives projections from superficial laminae of the medullary dorsal horn (MDH) and has neurons activated with capsaicin injections into the temporalis muscle. Injections of either biotinylated dextran amine (BDA) into the MDH or fluorogold (FG)/fluorescent microbeads into the cmVLM showed projections from lamina I and II of the MDH to the cmVLM. Morphometric analysis showed the retrogradely-labeled neurons were small (area 88.7 µm(2)±3.4) and mostly fusiform in shape. Injections (20-50 µl) of 0.5% capsaicin into the temporalis muscle and subsequent immunohistochemistry for c-Fos showed nuclei labeled in the dorsomedial trigeminocervical complex (TCC), the cmVLM, the lateral medulla, and the internal lateral subnucleus of the parabrachial complex (PBil). Additional labeling with c-Fos was seen in the subnucleus interpolaris of the spinal trigeminal nucleus, the rostral ventrolateral medulla, the superior salivatory nucleus, the rostral ventromedial medulla, and the A1, A5, A7 and subcoeruleus catecholamine areas. Injections of FG into the PBil produced robust label in the lateral medulla and cmVLM while injections of BDA into the lateral medulla showed projections to the PBil. Immunohistochemical experiments to antibodies against substance P, the substance P receptor (NK1), calcitonin gene regulating peptide, leucine enkephalin, VRL1 (TPRV2) receptors and neuropeptide Y showed that these peptides/receptors densely stained the cmVLM. We suggest the MDH- cmVLM projection is important for pain from head and neck areas. We offer a potential new pathway for regulating deep pain via the neurons of the TCC, the cmVLM, the lateral medulla, and the PBil and propose these areas compose a trigeminoreticular pathway, possibly the trigeminal homologue of the spinoreticulothalamic pathway.
Collapse
Affiliation(s)
- W Michael Panneton
- Department of Pharmacological and Physiological Science, St. Louis University School of Medicine, St. Louis, Missouri, United States of America.
| | | | | |
Collapse
|
13
|
White JPM, Ko CW, Fidalgo AR, Cibelli M, Paule CC, Anderson PJ, Cruz C, Gomba S, Matesz K, Veress G, Avelino A, Nagy I. Severe burn injury induces a characteristic activation of extracellular signal-regulated kinase 1/2 in spinal dorsal horn neurons. Eur J Pain 2011; 15:683-90. [PMID: 21371920 DOI: 10.1016/j.ejpain.2010.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 12/02/2010] [Accepted: 12/21/2010] [Indexed: 01/18/2023]
Abstract
We have studied scalding-type burn injury-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2) in the spinal dorsal horn, which is a recognised marker for spinal nociceptive processing. At 5min after severe scalding injury to mouse hind-paw, a substantial number of phosphorylated ERK1/2 (pERK1/2) immunopositive neurons were found in the ipsilateral dorsal horn. At 1h post-injury, the number of pERK1/2-labelled neurons remained substantially the same. However, at 3h post-injury, a further increase in the number of labelled neurons was found on the ipsilateral side, while a remarkable increase in the number of labelled neurons on the contralateral side resulted in there being no significant difference between the extent of the labelling on both sides. By 6h post-injury, the number of labelled neurons was reduced on both sides without there being significant difference between the two sides. A similar pattern of severe scalding injury-induced activation of ERK1/2 in spinal dorsal horn neurons over the same time-course was found in mice which lacked the transient receptor potential type 1 receptor (TRPV1) except that the extent to which ERK1/2 was activated in the ipsilateral dorsal horn at 5 min post-injury was significantly greater in wild-type animals when compared to TRPV1 null animals. This difference in activation of ERK1/2 in spinal dorsal horn neurons was abolished within 1h after injury, demonstrating that TRPV1 is not essential for the maintenance of ongoing spinal nociceptive processing in inflammatory pain conditions in mouse resulting from at least certain types of severe burn injury.
Collapse
Affiliation(s)
- John P M White
- Section of Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, 369, Fulham Road, London SW10 9NH, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
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.
Collapse
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.
| |
Collapse
|
15
|
Liu G, Xie C, Sun F, Xu X, Yang Y, Zhang T, Deng Y, Wang D, Huang Z, Yang L, Huang S, Wang Q, Liu G, Zhong D, Miao X. Clinical significance of transient receptor potential vanilloid 2 expression in human hepatocellular carcinoma. ACTA ACUST UNITED AC 2010; 197:54-9. [DOI: 10.1016/j.cancergencyto.2009.08.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Revised: 08/02/2009] [Accepted: 08/02/2009] [Indexed: 10/19/2022]
|
16
|
Shin JW, Pancaro C, Wang CF, Gerner P. The Effects of Resiniferatoxin in an Experimental Rat Thoracotomy Model. Anesth Analg 2010; 110:228-32. [DOI: 10.1213/ane.0b013e3181c5c89a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
17
|
Suter MR, Berta T, Gao YJ, Decosterd I, Ji RR. Large A-fiber activity is required for microglial proliferation and p38 MAPK activation in the spinal cord: different effects of resiniferatoxin and bupivacaine on spinal microglial changes after spared nerve injury. Mol Pain 2009; 5:53. [PMID: 19772627 PMCID: PMC2759920 DOI: 10.1186/1744-8069-5-53] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 09/22/2009] [Indexed: 12/19/2022] Open
Abstract
Background After peripheral nerve injury, spontaneous ectopic activity arising from the peripheral axons plays an important role in inducing central sensitization and neuropathic pain. Recent evidence indicates that activation of spinal cord microglia also contributes to the development of neuropathic pain. In particular, activation of p38 mitogen-activated protein kinase (MAPK) in spinal microglia is required for the development of mechanical allodynia. However, activity-dependent activation of microglia after nerve injury has not been fully addressed. To determine whether spontaneous activity from C- or A-fibers is required for microglial activation, we used resiniferatoxin (RTX) to block the conduction of transient receptor potential vanilloid subtype 1 (TRPV1) positive fibers (mostly C- and Aδ-fibers) and bupivacaine microspheres to block all fibers of the sciatic nerve in rats before spared nerve injury (SNI), and observed spinal microglial changes 2 days later. Results SNI induced robust mechanical allodynia and p38 activation in spinal microglia. SNI also induced marked cell proliferation in the spinal cord, and all the proliferating cells (BrdU+) were microglia (Iba1+). Bupivacaine induced a complete sensory and motor blockade and also significantly inhibited p38 activation and microglial proliferation in the spinal cord. In contrast, and although it produced an efficient nociceptive block, RTX failed to inhibit p38 activation and microglial proliferation in the spinal cord. Conclusion (1) Blocking peripheral input in TRPV1-positive fibers (presumably C-fibers) is not enough to prevent nerve injury-induced spinal microglial activation. (2) Peripheral input from large myelinated fibers is important for microglial activation. (3) Microglial activation is associated with mechanical allodynia.
Collapse
Affiliation(s)
- Marc R Suter
- Pain Research Center, Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
| | | | | | | | | |
Collapse
|
18
|
Shimohira D, Kido MA, Danjo A, Takao T, Wang B, Zhang JQ, Yamaza T, Masuko S, Goto M, Tanaka T. TRPV2 expression in rat oral mucosa. Histochem Cell Biol 2009; 132:423-33. [PMID: 19579031 DOI: 10.1007/s00418-009-0616-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2009] [Indexed: 11/25/2022]
Abstract
The oral mucosa is a highly specialised, stratified epithelium that confers protection from infection and physical, chemical and thermal stimuli. The non-keratinised junctional epithelium surrounds each tooth like a collar and is easily attacked by foreign substances from the oral sulcus. We found that TRPV2, a temperature-gated channel, is highly expressed in junctional epithelial cells, but not in oral sulcular epithelial cells or oral epithelial cells. Dual or triple immunolabelling with immunocompetent cell markers also revealed TRPV2 expression in Langerhans cells and in dendritic cells and macrophages. Electron microscopy disclosed TRPV2 immunoreactivity in the unmyelinated and thinly myelinated axons within the connective tissue underlying the epithelium. TRPV2 labelling was also observed in venule endothelial cells. The electron-dense immunoreaction in junctional epithelial cells, macrophages and neural axons occurred on the plasma membrane, on invaginations of the plasma membrane and in vesicular structures. Because TRPV2 has been shown to respond to temperature, hypotonicity and mechanical stimuli, gingival cells expressing TRPV2 may act as sensor cells, detecting changes in the physical and chemical environment, and may play a role in subsequent defence mechanisms.
Collapse
Affiliation(s)
- Daiji Shimohira
- Department of Oral Anatomy and Cell Biology, Graduate School of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Axelsson HE, Minde JK, Sonesson A, Toolanen G, Högestätt ED, Zygmunt PM. Transient receptor potential vanilloid 1, vanilloid 2 and melastatin 8 immunoreactive nerve fibers in human skin from individuals with and without Norrbottnian congenital insensitivity to pain. Neuroscience 2009; 162:1322-32. [PMID: 19482060 DOI: 10.1016/j.neuroscience.2009.05.052] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 05/13/2009] [Accepted: 05/15/2009] [Indexed: 10/20/2022]
Abstract
Transient receptor potential vanilloid 1 (TRPV1), vanilloid 2 (TRPV2) and melastatin 8 (TRPM8) are thermosensitive cation channels expressed on primary sensory neurons. In contrast to TRPV1, which is present on nociceptive primary afferents and keratinocytes in human skin, less is known about the distribution of TRPV2 and TRPM8 in this tissue. Immunohistochemistry of human forearm skin identified TRPV2 and TRPM8 immunoreactive nerve fibers in epidermis-papillary dermis and around blood vessels and hair follicles in dermis, although these nerve fibers were less abundant than TRPV1 immunoreactive nerve fibers throughout the skin. The TRPV2 and TRPM8 immunoreactive nerve fibers also showed immunoreactivity for calcitonin gene-related peptide (CGRP) and to a lesser extent substance P (SP). Neither of the TRP ion channels co-localized with neurofilament 200 kDa (NF200), vasoactive intestinal peptide (VIP) or tyrosine hydroxylase (TH). Nerve fibers immunoreactive for TRPV1, TRPV2, TRPM8, CGRP and SP were absent or substantially reduced in number in individuals with Norrbottnian congenital insensitivity to pain, an autosomal disease selectively affecting the development of C-fiber and Adelta-fiber primary afferents. Quantitative real time PCR detected mRNA transcripts encoding TRPV1 and TRPV2, but not TRPM8, in skin from healthy volunteers, suggesting that these ion channels are also expressed extraneuronally. In conclusion, nerve fibers in human skin express TRPV1, TRPV2 and TRPM8 that co-localize with the sensory neuropeptides CGRP and SP, but not with NF200, VIP or TH. A dramatic loss of such nerve fibers was seen in skin from individuals with Norrbottnian congenital insensitivity to pain, further suggesting that these ion channels are expressed primarily on nociceptive primary sensory neurons in human skin.
Collapse
Affiliation(s)
- H E Axelsson
- Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University Hospital, SE-221 85 Lund, Sweden
| | | | | | | | | | | |
Collapse
|
20
|
Xu X, Wang P, Zou X, Li D, Fang L, Lin Q. Increases in transient receptor potential vanilloid-1 mRNA and protein in primary afferent neurons stimulated by protein kinase C and their possible role in neurogenic inflammation. J Neurosci Res 2009; 87:482-94. [PMID: 18752301 DOI: 10.1002/jnr.21844] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A recent study by our group demonstrates pharmacologically that the transient receptor potential vanilloid-1 (TRPV(1)) is activated by intradermal injection of capsaicin to initiate neurogenic inflammation by the release of neuropeptides in the periphery. In this study, expression of TRPV(1), phosphorylated protein kinase C (p-PKC), and calcitonin gene-related peptide (CGRP) in dorsal root ganglion (DRG) neurons was visualized by using immunofluorescence, real-time PCR, and Western blots to examine whether increases in TRPV(1) mRNA and protein levels evoked by capsaicin injection are subject to modulation by the activation of PKC and to analyze the role of this process in the pathogenesis of neurogenic inflammation. Capsaicin injection into the hindpaw skin of anesthetized rats evoked increases in the expression of TRPV(1), CGRP and p-PKC in mRNA and/or protein levels and in the number of single labeled TRPV(1), p-PKC, and CGRP neurons in ipsilateral L4-5 DRGs. Coexpressions of TRPV(1) with p-PKC and/or CGRP in DRG neurons were also significantly increased after CAP injection. These evoked expressions at both molecular and cellular levels were significantly inhibited after TRPV(1) receptors were blocked by 5'-iodoresiniferatoxin (5 microg) or PKC was inhibited by chelerythrine chloride (5 microg). Taken together, these results provide evidence that up-regulation of TRPV(1) mRNA and protein levels under inflammatory conditions evoked by capsaicin injection is subject to modulation by the PKC cascade in which increased CGRP level in DRG neurons may be related to the initiation of neurogenic inflammation. Thus, up-regulation of TRPV(1) receptors in DRG neurons seems critical for initiating acute neurogenic inflammation.
Collapse
Affiliation(s)
- Xijin Xu
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555-1069, USA
| | | | | | | | | | | |
Collapse
|
21
|
Xing J, Lu J, Li J. Contribution of nerve growth factor to augmented TRPV1 responses of muscle sensory neurons by femoral artery occlusion. Am J Physiol Heart Circ Physiol 2009; 296:H1380-7. [PMID: 19286963 DOI: 10.1152/ajpheart.00063.2009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In rats, hindlimb muscle ischemia induced by femoral artery occlusion augments the sympathetic nervous response to stimulation of transient receptor potential vanilloid type 1 (TRPV1) by injection of capsaicin into the arterial blood supply of the hindlimb muscles. The enhanced sympathetic response is due to alterations in TRPV1 receptor expression and its responsiveness in sensory neurons. The underlying mechanism by which TRPV1 receptor responses are increased after muscle vascular insufficiency/ischemia is unclear. In this report we tested the hypothesis that muscle ischemia elevates nerve growth factor (NGF) levels in primary afferent neurons, thereby increasing TRPV1 responsiveness. Muscle vascular insufficiency induced by the femoral artery ligation significantly increased NGF in the dorsal root ganglion (DRG) compared with sham controls. Furthermore, when NGF was infused in the hindlimb muscles of healthy rats (72 h using an osmotic minipump), the magnitude of the DRG neuron response to capsaicin was augmented (5.4 +/- 0.54 nA with NGF infusion vs. 3.0 +/- 0.17 nA in control; P < 0.05). With the addition of NGF in the culture dish containing the DRG neurons, the magnitude of the DRG neuron response to capsaicin was greater (6.4 +/- 0.27 nA; P < 0.05 vs. control) than that seen in control (2.9 +/- 0.16 nA). Note that this NGF effect was seen in isolectin B(4)-negative DRG neurons, a group of thin fiber nerves that contain neuropeptides and depend on NGF for survival. These data suggest that NGF affects a selective subpopulation of the afferent neurons in mediating augmented TRPV1 responses after femoral artery occlusion.
Collapse
Affiliation(s)
- Jihong Xing
- Heart and Vascular Institute and Dept. of Medicine, Pennsylvania State Univ. College of Medicine, Milton S. Hershey Medical Center, 500 Univ. Dr., Hershey, PA 17033, USA
| | | | | |
Collapse
|
22
|
Li D, Ren Y, Xu X, Zou X, Fang L, Lin Q. Sensitization of primary afferent nociceptors induced by intradermal capsaicin involves the peripheral release of calcitonin gene-related Peptide driven by dorsal root reflexes. THE JOURNAL OF PAIN 2008; 9:1155-68. [PMID: 18701354 DOI: 10.1016/j.jpain.2008.06.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 06/12/2008] [Accepted: 06/18/2008] [Indexed: 10/21/2022]
Abstract
UNLABELLED Neuropeptides released from axons of primary afferent nociceptive neurons are the key elements for the incidence of neurogenic inflammation and their release is associated with dorsal root reflexes (DRRs). However, whether the release is due to the triggering of DRRs and plays a role in inflammation-induced pain still remain to be determined. The present study assessed the role of calcitonin gene-related peptide (CGRP) in sensitization of primary afferent nociceptors induced by activation of transient receptor potential vanilloid-1 (TRPV(1)) after intradermal injection of capsaicin and determined if this release is due to activation of primary afferent neurons antidromically by triggering of DRRs. Under dorsal root intact conditions, primary afferent nociceptive fibers recorded in anesthetized rats could be sensitized by capsaicin injection, as shown by an increase in afferent responses and lowering of the response threshold to mechanical stimuli. After DRRs were removed by dorsal rhizotomy, the capsaicin-evoked sensitization was significantly reduced. In dorsal root intact rats, peripheral pretreatment with a CGRP receptor antagonist could dose-dependently reduce the capsaicin-induced sensitization. Peripheral post-treatment with CGRP could dose-dependently restore the capsaicin-induced sensitization under dorsal rhizotomized conditions. Capsaicin injection evoked increases in numbers of single and double labeled TRPV(1) and CGRP neurons in ipsilateral dorsal root ganglia (DRG). After dorsal rhizotomy, these evoked expressions were significantly inhibited. PERSPECTIVE These data indicate that the DRR-mediated neurogenic inflammation enhances sensitization of primary afferent nociceptors induced by capsaicin injection. The underlying mechanism involves antidromic activation of DRG neurons via upregulation of TRPV(1) receptors whereby CGRP is released peripherally.
Collapse
Affiliation(s)
- Dingge Li
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555-1069, USA
| | | | | | | | | | | |
Collapse
|
23
|
Shinoda M, Ogino A, Ozaki N, Urano H, Hironaka K, Yasui M, Sugiura Y. Involvement of TRPV1 in Nociceptive Behavior in a Rat Model of Cancer Pain. THE JOURNAL OF PAIN 2008; 9:687-99. [DOI: 10.1016/j.jpain.2008.02.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 01/19/2008] [Accepted: 02/26/2008] [Indexed: 10/22/2022]
|
24
|
Xing J, Gao Z, Lu J, Sinoway LI, Li J. Femoral artery occlusion augments TRPV1-mediated sympathetic responsiveness. Am J Physiol Heart Circ Physiol 2008; 295:H1262-H1269. [PMID: 18660449 DOI: 10.1152/ajpheart.00271.2008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Muscle metabolic by-products stimulate thin fiber muscle afferent nerves and evoke reflex increases in blood pressure and sympathetic nerve activity. Previous studies reported that chemically sensitive transient receptor potential vanilloid type 1 (TRPV1) channels present on sensory muscle afferent neurons have an important impact on sympathetically mediated cardiovascular responses. The reflex-mediated reduction in blood flow to skeletal muscle leads to limited exercise capacity in patients with peripheral arterial occlusive disease. Thus, in this study, we tested the hypothesis that the expression of enhanced TRPV1 receptor and its responsiveness in primary afferent neurons innervating muscles initiate exaggerated reflex sympathetic responses after vascular insufficiency to the muscle. Muscle vascular insufficiency was induced by the femoral artery ligation in rats for 24 h. Our data show that 1) the ligation surgery leads to the upregulation of TRPV1 expression in the dorsal root ganglion; 2) the magnitude of the dorsal root ganglion neuron TRPV1 response induced by capsaicin is greater in vascular insufficiency (4.0 +/- 0.31 nA, P < 0.05 vs. sham-operated control) than that in sham-operated control (2.9 +/- 0.23 nA); and 3) renal sympathetic nerve activity and mean arterial pressure responses to capsaicin (0.5 microg/kg body wt) are also enhanced by vascular insufficiency (54 +/- 11%, 9 +/- 2 mmHg in sham-operated controls vs. 98 +/- 13%, 33 +/- 5 mmHg after vascular insufficiency, P < 0.05). In conclusion, sympathetic nerve responses to the activation of metabolite-sensitive TRPV1 receptors are augmented in rats with the femoral artery occlusion compared with sham-operated control animals, due to alterations in the expression of TRPV1 receptor and its responsiveness in sensory neurons.
Collapse
Affiliation(s)
- Jihong Xing
- Pennsylvania State Heart and Vascular Institute, The Pennsylvania State University College of Medicine, The Milton S. Hershey Medical Ctr., 500 Univ. Dr., Hershey, PA 17033, USA
| | | | | | | | | |
Collapse
|
25
|
Xing J, Sinoway L, Li J. Differential responses of sensory neurones innervating glycolytic and oxidative muscle to protons and capsaicin. J Physiol 2008; 586:3245-52. [PMID: 18450773 DOI: 10.1113/jphysiol.2008.154450] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Activation of thin fibre muscle afferent nerves by metabolic by-products plays a critical role in the initiation and maintenance of the autonomic response to exercise and the metabolic profile of active muscle can influence the response. The purpose of this report was to determine the responsiveness of sensory neurones innervating muscles comprising predominantly glycolytic and oxidative fibres to protons and capsaicin using whole-cell patch clamp methods. Dorsal root ganglion (DRG) neurones from 4- to 6-week-old rats were labelled by injecting the fluorescence tracer DiI into the muscle 3-5 days prior to the recording experiments. The percentage of the DRG neurones innervating glycolytic and oxidative muscle was similar in response to both protons and capsaicin. However, the neurones innervating glycolytic muscle had greater inward current amplitude responses to protons and capsaicin as compared with oxidative muscle. The peak current amplitudes to pH 6.0 were 0.84 +/- 0.06 nA (oxidative muscle) versus 1.36 +/- 0.07 nA (glycolytic muscle, P < 0.05). The capsaicin-induced current amplitudes were 2.3 +/- 0.15 nA (oxidative muscle) versus 3.1 +/- 0.21 nA (glycolytic muscle, P < 0.05). Of neurones that responded to pH 6.0 with a sustained current, 88% also responded to capsaicin. Capsaicin exposure enhanced the proton responsiveness in the neurones innervating the muscle; and protons also increased the capsaicin response. These data suggest that (1) receptors mediating protons and capsaicin responses coexist in the DRG neurones innervating muscle; (2) the responsiveness of acidosis and capsaicin can be sensitized by each other; and (3) DRG neurones with nerve endings in a glycolytic muscle developed greater inward current responses to protons and capsaicin than did those with nerve endings in an oxidative muscle.
Collapse
Affiliation(s)
- Jihong Xing
- Penn State Heart & Vascular Institute and Department of Medicine, The Pennsylvania State University College of Medicine, The Milton S. Hershey Medical Center, Hershey, PA 17033, USA
| | | | | |
Collapse
|
26
|
Gao Z, Koba S, Sinoway L, Li J. 20-HETE increases renal sympathetic nerve activity via activation of chemically and mechanically sensitive muscle afferents. J Physiol 2008; 586:2581-91. [PMID: 18372304 DOI: 10.1113/jphysiol.2008.150730] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Arachidonic acid and its metabolites produced via cyclooxygenase (COX) and lipoxygenase pathways have been reported to contribute to the cardiovascular reflexes evoked by stimulating thin fibre muscle afferents during muscle contraction. 20-Hydroxyeicosatetraenoic acid (20-HETE), a primarily metabolized product of arachidonic acid by cytochrome P450 enzymes, can be accumulated in contracting muscles. Thus, the purpose of this study was to determine the role of 20-HETE in modulating the reflex sympathetic responses to activation of chemically and mechanically sensitive muscle afferents. The renal sympathetic nerve activity (RSNA) and cardiovascular responses were examined after injections of 20-HETE into the arterial blood supply of the hindlimb muscles of decerebrated rats. This induced a dose-dependent increases in RSNA and mean arterial pressure (MAP). We also tested the hypothesis that 20-HETE would sensitize muscle afferents and, thereby, augment the RSNA and blood pressure response to muscle stretch. The results show that arterial infusion of 20-HETE significantly enhanced the RSNA and MAP responses to muscle stretch. In contrast, N-hydroxy-N'-(4-butyl-2-methylphenyl)formamidine, a potent inhibitor of 20-HETE production, attenuated the reflex muscle responses. Furthermore, the sensitizing effect of 20-HETE on the muscle reflex was significantly attenuated after blocking COX activity with indomethacin. Our data suggest that 20-HETE plays a role in modulating muscle afferent-mediated sympathetic responses, probably through engagement of a COX-dependent mechanism.
Collapse
Affiliation(s)
- Zhaohui Gao
- Penn State Heart & Vascular Institute, Pennsylvania State University College of Medicine, The Milton S. Hershey Medical Center, Hershey, PA 17033, USA
| | | | | | | |
Collapse
|
27
|
Yamamoto Y, Sato Y, Taniguchi K. Distribution of TRPV1- and TRPV2-immunoreactive afferent nerve endings in rat trachea. J Anat 2007; 211:775-83. [PMID: 17979952 DOI: 10.1111/j.1469-7580.2007.00821.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Nociception in the trachea is important for respiratory modulation. We investigated the distribution, neurochemical characteristics, and origin of nerve endings with immunoreactivity for candidate sensor channels, TRPV1 and TRPV2, in rat trachea. In the epithelial layer, the intraepithelial nerve endings and dense subepithelial network of nerve fibers were immunoreactive for TRPV1. In contrast, TRPV2 immunoreactivity was observed mainly in nerve fibers of the tracheal submucosal layer and in several intrinsic ganglion cells in the peritracheal plexus. Double immunostaining revealed that some TRPV1-immunoreactive nerve fibers were also immunoreactive for substance P or calcitonin gene-related peptide, but neither neuropeptide colocalized with TRPV2. Injection of the retrograde tracer, fast blue, into the tracheal wall near the thoracic inlet demonstrated labeled neurons in the jugular, nodose, and dorsal root ganglia at segmental levels of C2-C8. In the jugular and nodose ganglia, 59.3% (70/118) and 10.7% (17/159), respectively, of fast blue-labeled neurons were immunoreactive for TRPV1, compared to 8.8% (8/91) and 2.6% (5/191) for TRPV2-immunoreactive. Our results indicate that TRPV1-immunoreactive nerve endings are important for tracheal nociception, and the different expression patterns of TRPV1 and TRPV2 with neuropeptides may reflect different subpopulations of sensory neurons.
Collapse
Affiliation(s)
- Yoshio Yamamoto
- Laboratory of Veterinary Biochemistry and Cell Biology, Department of Veterinary Sciences, Faculty of Agriculture, Iwate University, Morioka, Japan.
| | | | | |
Collapse
|
28
|
Dense transient receptor potential cation channel, vanilloid family, type 2 (TRPV2) immunoreactivity defines a subset of motoneurons in the dorsal lateral nucleus of the spinal cord, the nucleus ambiguus and the trigeminal motor nucleus in rat. Neuroscience 2007; 151:164-73. [PMID: 18063314 DOI: 10.1016/j.neuroscience.2007.09.073] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 08/31/2007] [Accepted: 09/14/2007] [Indexed: 01/29/2023]
Abstract
The transient receptor potential cation channel, vanilloid family, type 2 (TRPV2) is a member of the TRPV family of proteins and is a homologue of the capsaicin/vanilloid receptor (transient receptor potential cation channel, vanilloid family, type 1, TRPV1). Like TRPV1, TRPV2 is expressed in a subset of dorsal root ganglia (DRG) neurons that project to superficial laminae of the spinal cord dorsal horn. Because noxious heat (>52 degrees C) activates TRPV2 in transfected cells this channel has been implicated in the processing of high intensity thermal pain messages in vivo. In contrast to TRPV1, however, which is restricted to small diameter DRG neurons, there is significant TRPV2 immunoreactivity in a variety of CNS regions. The present report focuses on a subset of neurons in the brainstem and spinal cord of the rat including the dorsal lateral nucleus (DLN) of the spinal cord, the nucleus ambiguus, and the motor trigeminal nucleus. Double label immunocytochemistry with markers of motoneurons, combined with retrograde labeling, established that these cells are, in fact, motoneurons. With the exception of their smaller diameter, these cells did not differ from other motoneurons, which are only lightly TRPV2-immunoreactive. As for the majority of DLN neurons, the densely-labeled populations co-express androgen receptor and follow normal DLN ontogeny. The functional significance of the very intense TRPV2 expression in these three distinct spinal cord and brainstem motoneurons groups remains to be determined.
Collapse
|
29
|
Bang S, Kim KY, Yoo S, Lee SH, Hwang SW. Transient receptor potential V2 expressed in sensory neurons is activated by probenecid. Neurosci Lett 2007; 425:120-5. [PMID: 17850966 DOI: 10.1016/j.neulet.2007.08.035] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Revised: 07/27/2007] [Accepted: 08/18/2007] [Indexed: 11/17/2022]
Abstract
Temperature-activated transient receptor potential ion channels (thermoTRPs) are known to function as ambient temperature sensors and are also involved in peripheral pain sensation. The thermoTRPs are activated by a variety of chemicals, of which specific activators have been utilized to explore the physiology of particular channels and sensory nerve subtypes. The use of capsaicin for TRPV1 is an exemplary case for nociceptor studies. In contrast, specific agents for another vanilloid subtype channel, TRPV2 have been lacking. Here, we show that probenecid is able to activate TRPV2 using electrophysiological and calcium imaging techniques with TRPV2-expressing HEK293T cells. Five other sensory thermoTRPs-TRPV1, TRPV3, TRPV4, TRPM8 and TRPA1-failed to show a response to this drug in the same heterologous expression system, suggesting that probenecid is a specific activator for TRPV2. Probenecid-evoked responses were also reproduced in a distinct subset of cultured trigeminal neurons that were responsive to 2-aminoethoxydiphenyl borate, a TRPV1-3 activator. The probenecid-sensitive neurons were mainly distributed in a medium to large-diameter population, in agreement with previous observations with TRPV2 immunolocalization. Under inflammation, probenecid elicited nociceptive behaviors in in vivo assays. These results suggest that TRPV2 is specifically activated by probenecid and that this chemical might be useful for investigation of pain-related TRPV2 function.
Collapse
Affiliation(s)
- Sangsu Bang
- Korea University Graduate School of Medicine, Seoul 136-705, Republic of Korea
| | | | | | | | | |
Collapse
|
30
|
Levine JD, Alessandri-Haber N. TRP channels: Targets for the relief of pain. Biochim Biophys Acta Mol Basis Dis 2007; 1772:989-1003. [PMID: 17321113 DOI: 10.1016/j.bbadis.2007.01.008] [Citation(s) in RCA: 254] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 01/12/2007] [Accepted: 01/16/2007] [Indexed: 02/01/2023]
Abstract
Patients with inflammatory or neuropathic pain experience hypersensitivity to mechanical, thermal and/or chemical stimuli. Given the diverse etiologies and molecular mechanisms of these pain syndromes, an approach to developing successful therapies may be to target ion channels that contribute to the detection of thermal, mechanical and chemical stimuli and promote the sensitization and activation of nociceptors. Transient Receptor Potential (TRP) channels have emerged as a family of evolutionarily conserved ligand-gated ion channels that contribute to the detection of physical stimuli. Six TRPs (TRPV1, TRPV2, TRPV3, TRPV4, TRPM8 and TRPA1) have been shown to be expressed in primary afferent nociceptors, pain sensing neurons, where they act as transducers for thermal, chemical and mechanical stimuli. This short review focuses on their contribution to pain hypersensitivity associated with peripheral inflammatory and neuropathic pain states.
Collapse
Affiliation(s)
- Jon D Levine
- Department of Oral and Maxillofacial Surgery, Box 0440, University of California, San Francisco, 521 Parnassus Avenue, San Francisco, CA 94143-0440, USA
| | | |
Collapse
|
31
|
Leffler A, Linte RM, Nau C, Reeh P, Babes A. A high-threshold heat-activated channel in cultured rat dorsal root ganglion neurons resembles TRPV2 and is blocked by gadolinium. Eur J Neurosci 2007; 26:12-22. [PMID: 17596195 DOI: 10.1111/j.1460-9568.2007.05643.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Heat-activated ion channels from the vanilloid-type TRP group (TRPV1-4) seem to be central for heat-sensitivity of nociceptive sensory neurons. Displaying a high-threshold (> 52 degrees C) for activation, TRPV2 was proposed to act as a sensor for intense noxious heat in mammalian sensory neurons. However, although TRPV2 is expressed in a distinct population of thinly myelinated primary afferents, a widespread expression in a variety of neuronal and non-neuronal tissues suggests a more diverse physiological role of TRPV2. In its role as a heat-sensor, TRPV2 has not been thoroughly characterized in terms of biophysical and pharmacological properties. In the present study, we demonstrate that the features of heterologously expressed rat TRPV2 closely resemble those of high-threshold heat-evoked currents in medium- and large-sized capsaicin-insensitive rat dorsal root ganglion (DRG) neurons. Both in TRPV2-expressing human embryonic kidney (HEK)293t cells and in DRGs, high-threshold heat-currents were sensitized by repeated activation and by the TRPV1-3 agonist, 2-aminoethoxydiphenyl borate (2-APB). In addition to a previously described block by ruthenium red, we identified the trivalent cations, lanthanum (La(3+)) and gadolinium (Gd(3+)) as potent blockers of TRPV2. Thus, we present a new pharmacological tool to distinguish between heat responses of TRPV2 and the closely related capsaicin-receptor, TRPV1, which is strongly sensitized by trivalent cations. We demonstrate that self-sensitization of heat-evoked currents through TRPV2 does not require extracellular calcium and that TRPV2 can be activated in cell-free membrane patches in the outside-out configuration. Taken together our results provide new evidence for a role of TRPV2 in mediating high-threshold heat responses in a subpopulation of mammalian sensory neurons.
Collapse
Affiliation(s)
- Andreas Leffler
- Department of Anaesthesiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | | | | | | | | |
Collapse
|
32
|
Gao Z, Li JD, Sinoway LI, Li J. Effect of muscle interstitial pH on P2X and TRPV1 receptor-mediated pressor response. J Appl Physiol (1985) 2007; 102:2288-93. [PMID: 17379752 DOI: 10.1152/japplphysiol.00161.2007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activation of purinergic P2X receptors and transient receptor potential vanilloid type 1 (TRPV1) on muscle afferent nerve evokes the pressor response. Because P2X and TRPV1 receptors are sensitive to changes in pH, the aim of this study was to examine the effects of muscle acidification on those receptor-mediated cardiovascular responses. In decerebrate rats, the pH in the hindlimb muscle was adjusted by infusing acidic Ringer solutions into the femoral artery. Dialysate was then collected using microdialysis probes inserted into the muscles, and pH was measured. The interstitial pH was 7.53+/-0.01, 7.22+/-0.02, 6.94+/-0.04, and 6.59+/-0.03 in response to arterial infusion of the Ringer solution at pH 7.4, 6.5, 5.5, and 4.5, respectively. Femoral arterial injection of alpha,beta-methylene-ATP (P2X receptor agonist) in the concentration of 0.25 mM (volume, 0.15-0.25 ml; injection duration, 1 min) at the infused pH of 7.4, 6.5, and 5.5 increased mean arterial pressure (MAP) by 29+/-2, 24+/-3, and 21+/-3 mmHg, respectively (P<0.05, pH 5.5 vs. pH 7.4). When pH levels in the infused solution were 7.4, 6.5, 5.5, and 4.5, capsaicin (1 microg/kg), a TRPV1 agonist, was injected into the artery. This elevated MAP by 29+/-4, 33+/-2, 35+/-3, and 40+/-3 mmHg, respectively (P<0.05, pH 4.5 vs. pH 7.4). Furthermore, blocking acid-sensing ion channel (ASIC) blunted pH effects on TRPV1 response. Our data indicate that 1) muscle acidosis attenuates P2X-mediated pressor response but enhances TRPV1 response; 2) exaggerated TRPV1 response may require lower pH in muscle, and the effect is likely to be mediated via ASIC mechanisms. This study provides evidence that muscle pH may be important in modulating P2X and TRPV1 responsiveness in exercising muscle.
Collapse
Affiliation(s)
- Zhaohui Gao
- Heart and Vascular Institute H047, Penn State College of Medicine, Milton S. Hershey Medical Center, 500 University Dr., Hershey, PA 17033, USA
| | | | | | | |
Collapse
|
33
|
Abstract
Animals sense temperature--either cold or hot--by the direct activation of temperature-sensitive members of the TRP family of ion channels, the thermo-TRPs. To date, six TRP channels--TRPV1-4, TRPM8 and TRPA1--have been reported to be directly activated by heat and to be involved in thermosensation. Temperature sensing can be modulated by phosphorylation of intracellular residues by protein kinases or by insertion of new channels into the cell membrane. In this review we provide a brief overview of the properties of thermo-TRPs, and we summarise signalling pathways involved in their regulation.
Collapse
Affiliation(s)
- Jiehong Huang
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | | | | |
Collapse
|
34
|
Tominaga M. The Role of TRP Channels in Thermosensation. TRP ION CHANNEL FUNCTION IN SENSORY TRANSDUCTION AND CELLULAR SIGNALING CASCADES 2006. [DOI: 10.1201/9781420005844.ch20] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
35
|
Ren Y, Zou X, Fang L, Lin Q. Involvement of peripheral purinoceptors in sympathetic modulation of capsaicin-induced sensitization of primary afferent fibers. J Neurophysiol 2006; 96:2207-16. [PMID: 16885522 DOI: 10.1152/jn.00502.2006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Purinoceptors are distributed in primary afferent terminals, where transmission of nociceptive information is modulated by these receptors. In the present study, we evaluated whether the activation or blockade of purinoceptors of subtypes P2X and P2Y in the periphery affected the sensitization of primary afferents induced by intradermal injection of capsaicin (CAP) and examined their role in sympathetic modulation of sensitization of primary nociceptive afferents. Afferent activity was recorded from single Adelta- and C-primary afferent fibers in the tibial nerve in anesthetized rats. Peripheral pretreatment with alpha,beta-methylene adenosine 5'-triphosphate (alpha,beta-meATP), a P2X-selective receptor agonist, could potentiate the CAP-induced enhancement of responses of Adelta- and C-primary afferent nociceptive fibers to mechanical stimuli in sympathetically intact rats. After sympathetic denervation, the enhanced responses of both Adelta- and C-fibers after CAP injection were dramatically reduced. However, this reduction could be restored when P2X receptors were activated by alpha,beta-meATP. A blockade of P2X receptors by pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid could significantly reduce the CAP-induced sensitization of Adelta- and C-fibers. Pretreatment with uridine 5'-triphosphate, a P2Y-selective receptor agonist, did not significantly affect or restore the CAP-induced sensitization of Adelta- and C-fibers under sympathetically intact or sympathectomized conditions. Our study supports the view that ATP plays a role in modulation of primary afferent nociceptor sensitivity mainly by P2X receptors. Combined with our previous study, our data also provide further evidence that the sensitization of primary afferent nociceptors is subject to sympathetic modulation by activation of P2X as well as alpha(1)-adrenergic receptors.
Collapse
Affiliation(s)
- Yong Ren
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-1069, USA
| | | | | | | |
Collapse
|
36
|
Tsukagoshi M, Goris RC, Funakoshi K. Differential distribution of vanilloid receptors in the primary sensory neurons projecting to the dorsal skin and muscles. Histochem Cell Biol 2006; 126:343-52. [PMID: 16541240 DOI: 10.1007/s00418-006-0167-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2006] [Indexed: 11/30/2022]
Abstract
We examined transient receptor potential (TRP) V1 and TRPV2 expression in calcitonin gene-related peptide (CGRP) positive (+) primary sensory neurons projecting to the skin and skeletal muscles of the rat dorsum. Among the dorsal root ganglia at the levels from C2 to Th1, 34.9% of neurons projecting to the skin were positive for CGRP, and 32.6% or 21.6% of neurons projecting to the trapezius muscle or the longissimus muscle were positive for CGRP. Of the small CGRP+ neurons projecting to the skin, 53.5% were positive for TRPV1, 11.6% were positive for TRPV2. Of the small CGRP+ neurons projecting to the trapezius or the longissimus, 53.1 or 53.2% were positive for TRPV1, 8.8 or 8.3% were positive for TRPV2, respectively. In the periphery, 29.3% of CGRP+ nerve fibers were positive for TRPV1 in the skin, whereas 65.0 or 59.8% were positive in the trapezius or the longissimus. Therefore, the present study showed that the percentage of CGRP+ neurons projecting to the trapezius is higher than that to the longissimus, and that the co-localization percentage of CGRP and TRPV1 on the sensory nerves was also higher in the trapezius than in the longissimus and the skin.
Collapse
Affiliation(s)
- Midori Tsukagoshi
- Collage of Nursing, Yokohama City University School of Medicine, 3-9 Fukuura, 236-0004, Kanazawa-ku, Yokohama, Japan
| | | | | |
Collapse
|
37
|
Rutter AR, Ma QP, Leveridge M, Bonnert TP. Heteromerization and colocalization of TrpV1 and TrpV2 in mammalian cell lines and rat dorsal root ganglia. Neuroreport 2006; 16:1735-9. [PMID: 16237318 DOI: 10.1097/01.wnr.0000185958.03841.0f] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Coassociation of the vanilloid transient receptor potential (Trp) ion channels, TrpV1 and TrpV2, was investigated by immunoprecipitation and immunofluorescence in transfected mammalian cell lines, rat dorsal root ganglia and spinal cord. TrpV1/TrpV2 heteromeric complexes were coimmunoprecipitated from human embryonic kidney cells and F-11 dorsal root ganglion hybridoma cells following their transient coexpression. Immunofluorescent labelling of transfected F-11 cells revealed colocalization of TrpV1 and TrpV2 at the cell surface. Immunoprecipitation from rat dorsal root ganglion lysates identified a minor population of receptor complexes composed of TrpV1/TrpV2 heteromers, consistent with a small proportion of cells double-labelled with TrpV1 and TrpV2 antibodies in rat dorsal root ganglion sections. TrpV1/TrpV2 receptor complexes may represent a functionally distinct ion channel complex that may increase the diversity observed within the Trp ion channel family.
Collapse
Affiliation(s)
- A Richard Rutter
- Department of Molecular and Cellular Neuroscience, Neuroscience Research Centre, Merck Sharp and Dohme Research Laboratories, Harlow, Essex, UK.
| | | | | | | |
Collapse
|
38
|
Bevan S. Chapter 7 TRP Channels as Thermosensors. CURRENT TOPICS IN MEMBRANES 2006. [DOI: 10.1016/s1063-5823(06)57006-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
39
|
Todd AJ. Chapter 6 Anatomy and neurochemistry of the dorsal horn. HANDBOOK OF CLINICAL NEUROLOGY 2006; 81:61-76. [PMID: 18808828 DOI: 10.1016/s0072-9752(06)80010-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
|
40
|
Willis WD. Chapter 3 The Nociceptive Membrane: Historical Overview. CURRENT TOPICS IN MEMBRANES 2006. [DOI: 10.1016/s1063-5823(06)57002-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
41
|
Fukuoka T, Noguchi K. Chapter 15 Expression Patterns and Histological Aspects of TRP Channels in Sensory Neurons. CURRENT TOPICS IN MEMBRANES 2006. [DOI: 10.1016/s1063-5823(06)57014-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
42
|
Shimosato G, Amaya F, Ueda M, Tanaka Y, Decosterd I, Tanaka M. Peripheral inflammation induces up-regulation of TRPV2 expression in rat DRG. Pain 2005; 119:225-232. [PMID: 16298071 DOI: 10.1016/j.pain.2005.10.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2005] [Revised: 08/26/2005] [Accepted: 10/10/2005] [Indexed: 10/25/2022]
Abstract
The transient receptor potential vanilloid subfamily member 2 (TRPV2) is a cation channel activated by temperatures above 52 degrees C. To analyze the contribution of TRPV2 to the development of inflammation-induced hyperalgesia, the expression of TRPV2 in primary sensory neurons was analyzed after intraplantar injection of complete Freund's adjuvant (CFA). Using specific antibodies, an increase in TRPV2-expressing neurons was identified after inflammation. TRPV2 expression is concentrated in a subset of medium-sized dorsal root ganglion neurons, independent of transient receptor potential vanilloid subfamily member 1 (TRPV1) expression. A similar distribution of TRPV2 was observed after inflammation. Intraplantar injection of nerve growth factor increased TRPV1 expression but not TRPV2, suggesting that induction of TRPV2 expression is driven by a mechanism distinct from that for TRPV1. Heat hyperalgesia assessment after chemical desensitization of TRPV1 by resiniferatoxin demonstrates a possible role for TRPV2 in inflammation at high temperatures (>56 degrees C). These results suggest that TRPV2 upregulation contributes to peripheral sensitization during inflammation and is responsible for pain hypersensitivity to noxious high temperature stimuli.
Collapse
Affiliation(s)
- Goshun Shimosato
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, 465 Kajiicho, Kamigyo-ku, Kyoto 602-8566, Japan Department of Anesthesiology Pain Research Group, Anesthesiology Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland Department of Cell Biology and Morphology (DBCM), Faculty of Biology and Medicine, Lausanne University, Lausanne, Switzerland Department of Anatomy, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | | | | | | | | | | |
Collapse
|
43
|
Liapi A, Wood JN. Extensive co-localization and heteromultimer formation of the vanilloid receptor-like protein TRPV2 and the capsaicin receptor TRPV1 in the adult rat cerebral cortex. Eur J Neurosci 2005; 22:825-34. [PMID: 16115206 DOI: 10.1111/j.1460-9568.2005.04270.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The capsaicin receptor TRPV1, a member of the transient receptor potential (TRP) family of calcium-selective ion channels, responds to noxious stimuli and is predominantly expressed in nociceptive neurons. The homologous receptor TRPV2 shows wide tissue distribution including some sensory neurons, where it is proposed to function as a heat sensor or a growth-factor-activated channel. Members of the TRP family of channels have been shown to interact, resulting in hybrid channels with new properties. We examined the possibility of multimer formation between TRPV1 and TRPV2, using biochemical techniques. We present evidence that TRPV1 and TRPV2 can heteromultimerize efficiently in vitro. By using immunohistochemistry we detected co-localization of the two receptors in rat dorsal root ganglia. TRPC4 transcripts are also detected in capsaicin-sensitive dorsal root ganglia neurons. We extended the search for TRPV1-TRPV2 co-localization in the brain, where we detected extensive co-expression of the two receptors in the IV, V and VI layer neurons of the adult rat cerebral cortex. Co-immunoprecipitation experiments confirmed the interaction of the two receptors in vivo, indicating heteromultimer formation in native tissue. Formation of heteromultimers between vanilloid receptors may increase the functional diversity of this receptor family.
Collapse
Affiliation(s)
- Anastasia Liapi
- Biology Department, University College London, Gower Street, London WC1E 6BT, UK
| | | |
Collapse
|
44
|
Gao Z, Henig O, Kehoe V, Sinoway LI, Li J. Vanilloid type 1 receptor and the acid-sensing ion channel mediate acid phosphate activation of muscle afferent nerves in rats. J Appl Physiol (1985) 2005; 100:421-6. [PMID: 16210435 DOI: 10.1152/japplphysiol.00659.2005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Reflex cardiovascular responses to contracting skeletal muscle are mediated by mechanical and metabolic stimulation of thin-fiber muscle afferents. Diprotonated phosphate (H2PO4-) excites those thin-fiber nerves and evokes the muscle pressor reflex. The receptors mediating this response are unknown. Thus we examined the role played by purinergic receptors, vanilloid type 1 receptors (VR1), and acid-sensing ion channels (ASIC) in mediating H2PO4- -evoked pressor responses. Phosphate and blocking agents were injected into the arterial blood supply of the hindlimb muscles of 53 decerebrated rats. H2PO4- (86 mM, pH 6.0) increased mean arterial pressure by 25 +/- 2 mmHg, whereas monoprotonated phosphate (HPO4(2-), pH 7.5) had no effect. Pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (a purinergic receptor antagonist, 2 mM) did not block the response. However, capsazepine (a VR1 antagonist, 1 mg/kg) attenuated the reflex by 60% and amiloride (an ASIC blocker, 6 microg/kg) by 52%. Of note, the H2PO4- -induced pressor response was attenuated by 87% when both capsazepine and amiloride were injected before the H2PO4-. In conclusion, VR1 and ASIC mediate the pressor response due to H2PO4-. The H2PO4- -evoked response was greater when VR1 and ASIC blockers were given simultaneously than when the respective blockers were given separately. Our laboratory's previous study has shown that H+ stimulates ASIC (but not VR1) on thin-fiber afferent nerves in evoking the reflex response. Thus VR1 and ASIC are likely to play a coordinated and interactive role in processing the muscle afferent response to H2PO4-. Furthermore, the physiological mechanisms mediating the response to H+ and H2PO4- are likely to be different.
Collapse
Affiliation(s)
- Zhaohui Gao
- Department of Medicine, Division of Cardiology, H047, Penn State College of Medicine, Milton S. Hershey Medical Center, 500 Univ. Dr., Hershey, PA 17033, USA
| | | | | | | | | |
Collapse
|
45
|
Tamura S, Morikawa Y, Senba E. TRPV2, a capsaicin receptor homologue, is expressed predominantly in the neurotrophin-3-dependent subpopulation of primary sensory neurons. Neuroscience 2005; 130:223-8. [PMID: 15561438 DOI: 10.1016/j.neuroscience.2004.09.021] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2004] [Indexed: 11/26/2022]
Abstract
TRPV2, a member of transient receptor potential ion channels, responds to high-threshold noxious heat, but neither to capsaicin nor to proton. Although TRPV2 is expressed in medium- to large-sized dorsal root ganglion (DRG) neurons with myelinated fibers in adult rodents, little is known about the neurotrophin dependence of TRPV2-positive neurons in the developing and adult DRGs of mice. In the present study, using immunohistochemistry, we found that TRPV2 was first expressed in DRG neurons at embryonic day (E) 11.5, when neither TRPV1 nor TRPM8 was detected yet. Double-immunofluorescence staining revealed that tyrosine kinase receptor C (TrkC) was expressed in most of TRPV2-positive DRG neurons at E11.5 and E13.5. In addition, the percentage of TRPV2-positive neurons in the total DRG neurons at E13.5 reached the same as that of adulthood. In adult DRGs, TrkC and Ret were expressed in 68% and 25% of TRPV2-positive neurons, respectively. These results suggest that TRPV2 is expressed predominantly in the NT-3-dependent subpopulation of DRG neurons throughout development and in adult mice.
Collapse
Affiliation(s)
- S Tamura
- Department of Anatomy and Neurobiology, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509 Japan
| | | | | |
Collapse
|
46
|
Abe J, Hosokawa H, Okazawa M, Kandachi M, Sawada Y, Yamanaka K, Matsumura K, Kobayashi S. TRPM8 protein localization in trigeminal ganglion and taste papillae. ACTA ACUST UNITED AC 2005; 136:91-8. [PMID: 15893591 DOI: 10.1016/j.molbrainres.2005.01.013] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Revised: 12/30/2004] [Accepted: 01/09/2005] [Indexed: 11/19/2022]
Abstract
TRPM8 is a TRP family cation channel which can be activated by cold stimuli or l-menthol. However, TRPM8 protein localization of nerve terminals in sensory organs remains unknown. Here we generated an antibody against TRPM8 and analyzed TRPM8 protein localization in trigeminal ganglia (TG) and in sensory nerve fibers in the tongue. TRPM8 immunoreactivity was detected in a subset of neurons with a small diameter in TG and in nerve fibers in the tongue. TRPM8-immunoreactive nerve fibers were rich in fungiform papillae, but sparse in foliate and circumvallate papillae. The TRPM8-immunoreactive nerve fibers reached the outer epithelial layer in each papilla, while no TRPM8-immunoreactive nerve fibers penetrated into taste buds. Double labeling analysis revealed that TRPM8 immunoreactivity was co-expressed with a part of TRPV1 or CGRP-immunoreactive neurons in TG. However, TRPM8 immunoreactivity was not observed in TRPV1- or CGRP-positive nerve fibers in fungiform, foliate, and circumvallate papillae. These results suggest that TRPM8 protein is present in sensory lingual nerve fibers mainly projected from TG and might work as cold and l-menthol receptors on tongue.
Collapse
Affiliation(s)
- Junji Abe
- Division of Biological Information, Department of Intelligence Science and Technology, Graduate School of Informatics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Abstract
We feel a wide range of temperatures spanning from cold to heat. Within this range, temperatures over about 43 degrees C and below about 15 degrees C evoke not only a thermal sensation, but also a feeling of pain. In mammals, six thermosensitive ion channels have been reported, all of which belong to the TRP (transient receptor potential) superfamily. These include TRPV1 (VR1), TRPV2 (VRL-1), TRPV3, TRPV4, TRPM8 (CMR1), and TRPA1 (ANKTM1). These channels exhibit distinct thermal activation thresholds (>43 degrees C for TRPV1, >52 degrees C for TRPV2, > approximately 34-38 degrees C for TRPV3, > approximately 27-35 degrees C for TRPV4, < approximately 25-28 degrees C for TRPM8 and <17 degrees C for TRPA1), and are expressed in primary sensory neurons as well as other tissues. The involvement of TRPV1 in thermal nociception has been demonstrated by multiple methods, including the analysis of TRPV1-deficient mice. TRPV2, TRPM8, and TRPA1 are also very likely to be involved in thermal nociception, because their activation thresholds are within the noxious range of temperatures.
Collapse
Affiliation(s)
- Makoto Tominaga
- Section of Cell Signaling, Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787, Japan.
| | | |
Collapse
|
48
|
Woodbury CJ, Zwick M, Wang S, Lawson JJ, Caterina MJ, Koltzenburg M, Albers KM, Koerber HR, Davis BM. Nociceptors lacking TRPV1 and TRPV2 have normal heat responses. J Neurosci 2004; 24:6410-5. [PMID: 15254097 PMCID: PMC6729548 DOI: 10.1523/jneurosci.1421-04.2004] [Citation(s) in RCA: 203] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Vanilloid receptor 1 (TRPV1) has been proposed to be the principal heat-responsive channel for nociceptive neurons. The skin of both rat and mouse receives major projections from primary sensory afferents that bind the plant lectin isolectin B4 (IB4). The majority of IB4-positive neurons are known to be heat-responsive nociceptors. Previous studies suggested that, unlike rat, mouse IB4-positive cutaneous afferents did not express TRPV1 immunoreactivity. Here, multiple antisera were used to confirm that mouse and rat have different distributions of TRPV1 and that TRPV1 immunoreactivity is absent in heat-sensitive nociceptors. Intracellular recording in TRPV1(-/-) mice was then used to confirm that TRPV1 was not required for detecting noxious heat. TRPV1(-/-) mice had more heat-sensitive neurons, and these neurons had normal temperature thresholds and response properties. Moreover, in TRPV1(-/-) mice, 82% of heat-responsive neurons did not express immunoreactivity for TRPV2, another putative noxious heat channel.
Collapse
Affiliation(s)
- C Jeffery Woodbury
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Li J, Sinoway AN, Gao Z, Maile MD, Pu M, Sinoway LI. Muscle mechanoreflex and metaboreflex responses after myocardial infarction in rats. Circulation 2004; 110:3049-54. [PMID: 15520319 DOI: 10.1161/01.cir.0000147188.46287.1b] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND During exercise, the sympathetic nervous system is activated and blood pressure and heart rate increase. In heart failure (HF), the muscle metaboreceptor contribution to sympathetic outflow is attenuated and the mechanoreceptor contribution is accentuated. Previous studies suggest that (1) capsaicin stimulates muscle metabosensitive vanilloid receptor subtype 1 (VR1), inducing a neurally mediated pressor response, and (2) activation of ATP-sensitive P2X receptors enhances the pressor response seen when muscle mechanoreceptors are engaged by muscle stretch. Thus, we hypothesized that the pressor response to VR1 stimulation would be smaller and the sensitizing effects of P2X stimulation greater in rats with HF due to chronic myocardial infarction (MI) than in controls. METHODS AND RESULTS Eight to 14 weeks after coronary ligation, rats with infarcts >35% had an increased left ventricular end-diastolic pressure and a marked increase in heart weight. Capsaicin injected into the arterial supply of the hindlimb increased blood pressure by 39% (baseline, 93.9+/-9.5 mm Hg) in control animals but only by 8% (baseline, 94.8+/-10.1 mm Hg) in rats with large MIs (P<0.05). P2X receptor stimulation by alpha,beta-methylene ATP enhanced the pressor response to muscle stretch by 42% in control animals and by 72% in rats with large MIs (P<0.05). CONCLUSIONS Compared with control animals, cardiovascular responses to VR1 stimulation are blunted and P2X-mediated responses are augmented in rats with HF owing to large MIs.
Collapse
Affiliation(s)
- Jianhua Li
- Division of Cardiology, H047, Penn State College of Medicine, 500 University Dr, Hershey, PA 17033, USA.
| | | | | | | | | | | |
Collapse
|
50
|
Ständer S, Moormann C, Schumacher M, Buddenkotte J, Artuc M, Shpacovitch V, Brzoska T, Lippert U, Henz BM, Luger TA, Metze D, Steinhoff M. Expression of vanilloid receptor subtype 1 in cutaneous sensory nerve fibers, mast cells, and epithelial cells of appendage structures. Exp Dermatol 2004; 13:129-39. [PMID: 14987252 DOI: 10.1111/j.0906-6705.2004.0178.x] [Citation(s) in RCA: 278] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The vanilloid receptor subtype 1 (VR1)/(TRPV1), binding capsaicin, is a non-selective cation channel that recently has been shown in human keratinocytes in vitro and in vivo. However, a description of VR1 localization in other cutaneous compartments in particular cutaneous nerve fibers is still lacking. We therefore investigated VR1 immunoreactivity as well as mRNA and protein expression in a series (n = 26) of normal (n = 7), diseased (n = 13) [prurigo nodularis (PN) (n = 10), generalized pruritus (n = 1), and mastocytosis (n = 2)], and capsaicin-treated human skin (n = 6). VR1 immunoreactivity could be observed in cutaneous sensory nerve fibers, mast cells, epidermal keratinocytes, dermal blood vessels, the inner root sheet and the infundibulum of hair follicles, differentiated sebocytes, sweat gland ducts, and the secretory portion of eccrine sweat glands. Upon reverse transcriptase-polymerase chain reaction and Western blot analysis, VR1 was detected in mast cells and keratinocytes from human skin. In pruritic skin of PN, VR1 expression was highly increased in epidermal keratinocytes and nerve fibers, which was normalized after capsaicin application. During capsaicin therapy, a reduction of neuropeptides (substance P, calcitonin gene-related peptide) was observed. After cessation of capsaicin therapy, neuropeptides re-accumulated in skin nerves. In conclusion, VR1 is widely distributed in the skin, suggesting a major role for this receptor, e.g. in nociception and neurogenic inflammation.
Collapse
Affiliation(s)
- Sonja Ständer
- Department of Dermatology, University of Münster, Muenster, Germany.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|