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Fardo F, Vinding MC, Allen M, Jensen TS, Finnerup NB. Delta and gamma oscillations in operculo-insular cortex underlie innocuous cold thermosensation. J Neurophysiol 2017; 117:1959-1968. [PMID: 28250150 PMCID: PMC5411475 DOI: 10.1152/jn.00843.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 02/07/2017] [Accepted: 02/07/2017] [Indexed: 01/21/2023] Open
Abstract
Using magnetoencephalography, we identified spatiotemporal features of central cold processing, with respect to the time course, oscillatory profile, and neural generators of cold-evoked responses in healthy human volunteers. Cold thermosensation was associated with low- and high-frequency oscillatory rhythms, both originating in operculo-insular regions. These results support further investigations of central cold processing using magnetoencephalography or EEG and the clinical utility of cold-evoked potentials for neurophysiological assessment of cold-related small-fiber function and damage. Cold-sensitive and nociceptive neural pathways interact to shape the quality and intensity of thermal and pain perception. Yet the central processing of cold thermosensation in the human brain has not been extensively studied. Here, we used magnetoencephalography and EEG in healthy volunteers to investigate the time course (evoked fields and potentials) and oscillatory activity associated with the perception of cold temperature changes. Nonnoxious cold stimuli consisting of Δ3°C and Δ5°C decrements from an adapting temperature of 35°C were delivered on the dorsum of the left hand via a contact thermode. Cold-evoked fields peaked at around 240 and 500 ms, at peak latencies similar to the N1 and P2 cold-evoked potentials. Importantly, cold-related changes in oscillatory power indicated that innocuous thermosensation is mediated by oscillatory activity in the range of delta (1–4 Hz) and gamma (55–90 Hz) rhythms, originating in operculo-insular cortical regions. We suggest that delta rhythms coordinate functional integration between operculo-insular and frontoparietal regions, while gamma rhythms reflect local sensory processing in operculo-insular areas. NEW & NOTEWORTHY Using magnetoencephalography, we identified spatiotemporal features of central cold processing, with respect to the time course, oscillatory profile, and neural generators of cold-evoked responses in healthy human volunteers. Cold thermosensation was associated with low- and high-frequency oscillatory rhythms, both originating in operculo-insular regions. These results support further investigations of central cold processing using magnetoencephalography or EEG and the clinical utility of cold-evoked potentials for neurophysiological assessment of cold-related small-fiber function and damage.
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Affiliation(s)
- Francesca Fardo
- Danish Pain Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; .,Interacting Minds Centre, Aarhus University, Aarhus, Denmark.,Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Mikkel C Vinding
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark.,Swedish National Facility for Magnetoencephalography, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Micah Allen
- Wellcome Trust Center for Neuroimaging, University College London, London, United Kingdom.,Institute of Cognitive Neuroscience, University College London, London, United Kingdom; and
| | - Troels Staehelin Jensen
- Danish Pain Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Nanna Brix Finnerup
- Danish Pain Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Paschke M, Tkachenko A, Ackermann K, Hutzler C, Henkler F, Luch A. Activation of the cold-receptor TRPM8 by low levels of menthol in tobacco products. Toxicol Lett 2017; 271:50-57. [PMID: 28238800 DOI: 10.1016/j.toxlet.2017.02.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/20/2017] [Accepted: 02/22/2017] [Indexed: 10/20/2022]
Abstract
Activation of the cold-receptor TRPM8 by menthol or other tobacco additives can suppress natural defense reactions such as coughing that usually would become effective as involuntary resistance against the inhalation of fumes. In Europe menthol is only regulated as flavor, but can be used as additive as long as no characteristic mint-like aroma will become noticeable in the end-product tobacco. The question needs to be addressed of whether such comparatively minor contents would be sufficient to trigger a measurable activation of TRPM8. In this study, we have analyzed both the contents of menthol and other natural TRPM8 agonists in tobacco products and developed a bioassay to determine the minimum concentrations of selected agonists to activate the TRPM8 receptor in cultured cells. The data confirm menthol as strongest natural agonist investigated. Based on these experiments and previously published data, we have estimated both the minimum menthol concentrations in cigarette smoke and in tobacco that are expected to trigger measurable physiological effects. According to our assessments, TRPM8 activation is likely to occur when cigarettes contain more than 50 micrograms of menthol. Importantly, menthol contents in cigarettes far below the typical levels that require declaration as "mentholated" would be sufficient to activate sensory receptors.
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Affiliation(s)
- Meike Paschke
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Anna Tkachenko
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Katja Ackermann
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Christoph Hutzler
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Frank Henkler
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany.
| | - Andreas Luch
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
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Role of the Excitability Brake Potassium Current I KD in Cold Allodynia Induced by Chronic Peripheral Nerve Injury. J Neurosci 2017; 37:3109-3126. [PMID: 28179555 DOI: 10.1523/jneurosci.3553-16.2017] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/24/2017] [Accepted: 01/26/2017] [Indexed: 11/21/2022] Open
Abstract
Cold allodynia is a common symptom of neuropathic and inflammatory pain following peripheral nerve injury. The mechanisms underlying this disabling sensory alteration are not entirely understood. In primary somatosensory neurons, cold sensitivity is mainly determined by a functional counterbalance between cold-activated TRPM8 channels and Shaker-like Kv1.1-1.2 channels underlying the excitability brake current IKD Here we studied the role of IKD in damage-triggered painful hypersensitivity to innocuous cold. We found that cold allodynia induced by chronic constriction injury (CCI) of the sciatic nerve in mice, was related to both an increase in the proportion of cold-sensitive neurons (CSNs) in DRGs contributing to the sciatic nerve, and a decrease in their cold temperature threshold. IKD density was reduced in high-threshold CSNs from CCI mice compared with sham animals, with no differences in cold-induced TRPM8-dependent current density. The electrophysiological properties and neurochemical profile of CSNs revealed an increase of nociceptive-like phenotype among neurons from CCI animals compared with sham mice. These results were validated using a mathematical model of CSNs, including IKD and TRPM8, showing that a reduction in IKD current density shifts the thermal threshold to higher temperatures and that the reduction of this current induces cold sensitivity in former cold-insensitive neurons expressing low levels of TRPM8-like current. Together, our results suggest that cold allodynia is largely due to a functional downregulation of IKD in both high-threshold CSNs and in a subpopulation of polymodal nociceptors expressing TRPM8, providing a general molecular and neural mechanism for this sensory alteration.SIGNIFICANCE STATEMENT This paper unveils the critical role of the brake potassium current IKD in damage-triggered cold allodynia. Using a well-known form of nerve injury and combining behavioral analysis, calcium imaging, patch clamping, and pharmacological tools, validated by mathematical modeling, we determined that the functional expression of IKD is reduced in sensory neurons in response to peripheral nerve damage. This downregulation not only enhances cold sensitivity of high-threshold cold thermoreceptors signaling cold discomfort, but it also transforms a subpopulation of polymodal nociceptors signaling pain into neurons activated by mild temperature drops. Our results suggest that cold allodynia is linked to a reduction of IKD in both high-threshold cold thermoreceptors and nociceptors expressing TRPM8, providing a general model for this form of cold-induced pain.
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Weight-Bearing Exercise and Foot Health in Native Americans. ACTA ACUST UNITED AC 2017; 15:184-195. [PMID: 26294899 DOI: 10.1891/1521-0987.15.4.184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Diabetes contributes to sensory peripheral neuropathy, which has been linked to lower limb abnormalities that raise the risk for foot ulcers and amputations. Because amputations are a reason for pain and hospitalization in those with diabetes, it is of critical importance to gain insight about prevention of ulcer development in this population. Although the American Diabetes Association (ADA) now recommends that individuals with neuropathy can engage in moderate-intensity weight-bearing activity (WBA), they must wear appropriate footwear and inspect their feet daily. The physical forces and inflammatory processes from WBA may contribute to plantar characteristics that lead to ulcers. The purpose of this study was to compare neuropathic status and foot characteristics in Native Americans according to WBA classification. The t tests for unequal sample sizes found that exercisers had more difficulty sensing baseline temperature than nonexercisers, except at the right foot (all p values < .05). By dividing groups into no/low risk and high risk for ulcer, a majority showed no/low risk according to touch and vibration sense. Exercisers demonstrated higher surface skin temperature gradients at the first metatarsal head, a plantar site where wounds tend to form. The more consistently exercisers performed, the higher the plan-tar pressures were at the right second (r = .24, p = .02) and third metatarsal heads (r = .26, p = .01). Findings from this investigation do not refute current ADA recommendations and further intervention studies are needed that are longitudinal and measures WBA more accurately.
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González A, Herrera G, Ugarte G, Restrepo C, Piña R, Pertusa M, Orio P, Madrid R. IKD Current in Cold Transduction and Damage-Triggered Cold Hypersensitivity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1015:265-277. [PMID: 29080031 DOI: 10.1007/978-3-319-62817-2_14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In primary sensory neurons of the spinal and trigeminal somatosensory system, cold-sensitivity is strongly dependent on the functional balance between TRPM8 channels, the main molecular entity responsible for the cold-activated excitatory current, and Shaker-like Kv1.1-1.2 potassium channels, the molecular counterpart underlying the excitability brake current IKD. This slow-inactivating outward K+ current reduces the excitability of cold thermoreceptor neurons increasing their thermal threshold, and prevents unspecific activation by cold of neurons of other somatosensory modalities. Here we examine the main biophysical properties of this current in primary sensory neurons, its central role in cold thermotransduction, and its contribution to alterations in cold sensitivity triggered by peripheral nerve damage.
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Affiliation(s)
- Alejandro González
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - Gaspar Herrera
- Centro Interdisciplinario de Neurociencia de Valparaíso and Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, 2340000, Valparaíso, Chile
| | - Gonzalo Ugarte
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - Carlos Restrepo
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - Ricardo Piña
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - María Pertusa
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso and Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, 2340000, Valparaíso, Chile
| | - Rodolfo Madrid
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile.
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Cellular permeation of large molecules mediated by TRPM8 channels. Neurosci Lett 2016; 639:59-67. [PMID: 28038937 DOI: 10.1016/j.neulet.2016.12.063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/23/2016] [Accepted: 12/24/2016] [Indexed: 11/24/2022]
Abstract
While most membrane channels are only capable of passing small ions, certain non-selective cation channels have been recently shown to have the capacity to permeate large cations. The mechanisms underlying large molecule permeation are unclear, but this property has been exploited pharmacologically to target molecules, such as nerve conduction blockers, to specific subsets of pain-sensing neurons (nociceptors) expressing the heat-gated transient receptor potential (TRP) channel TRPV1. However, it is not clear if the principal mediator of cold stimuli TRPM8 is capable of mediating the permeation large molecules across cell membranes, suggesting that TRPM8-positive nerves cannot be similarly targeted. Here we show that both heterologous cells and native sensory neurons expressing TRPM8 channels allow the permeation of the large fluorescent cation Po-Pro3. Po-Pro3 influx is blocked by TRPM8-specific antagonism and when channel activity is desensitized. The effects of the potent agonist WS-12 are TRPM8-specific and dye uptake mediated by TRPM8 channels is similar to that observed with TRPV1. Lastly, we find that as with TRPV1, activation of TRPM8 channels can be used as a means to target intracellular uptake of cell-impermeable sodium channel blockers. In a neuronal cell line expressing TRPM8 channels, voltage-gated sodium currents are blocked in the presence of the cell-impermeable, charged lidocaine derivative QX-314 and WS-12. These results show that the ability of somatosensory TRP channels to promote the permeation of large cations also includes TRPM8, thereby suggesting that novel approaches to alter cold pain can also be employed via conduction block in TRPM8-positive sensory neurons.
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Yamamoto A, Takahashi K, Saito S, Tominaga M, Ohta T. Two different avian cold-sensitive sensory neurons: Transient receptor potential melastatin 8 (TRPM8)-dependent and -independent activation mechanisms. Neuropharmacology 2016; 111:130-141. [DOI: 10.1016/j.neuropharm.2016.08.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 08/23/2016] [Accepted: 08/29/2016] [Indexed: 11/29/2022]
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Pérez de Vega MJ, Gómez-Monterrey I, Ferrer-Montiel A, González-Muñiz R. Transient Receptor Potential Melastatin 8 Channel (TRPM8) Modulation: Cool Entryway for Treating Pain and Cancer. J Med Chem 2016; 59:10006-10029. [PMID: 27437828 DOI: 10.1021/acs.jmedchem.6b00305] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
TRPM8 ion channels, the primary cold sensors in humans, are activated by innocuous cooling (<28 °C) and cooling compounds (menthol, icilin) and are implicated in sensing unpleasant cold stimuli as well as in mammalian thermoregulation. Overexpression of these thermoregulators in prostate cancer and in other life-threatening tumors, along with their contribution to an increasing number of pathological conditions, opens a plethora of medicinal chemistry opportunities to develop receptor modulators. This Perspective seeks to describe current known modulators for this ion channel because both agonists and antagonists may be useful for the treatment of most TRPM8-mediated pathologies. We primarily focus on SAR data for the different families of compounds and the pharmacological properties of the most promising ligands. Furthermore, we also address the knowledge about the channel structure, although still in its infancy, and the role of the TRPM8 protein signalplex to channel function and dysfunction. We finally outline the potential future prospects of the challenging TRPM8 drug discovery field.
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Affiliation(s)
| | - Isabel Gómez-Monterrey
- Dipartimento di Farmacia, Università "Federico II" de Napoli , Via D. Montesano 49, 80131, Naples, Italy
| | - Antonio Ferrer-Montiel
- Instituto de Biología Molecular y Celular. Universitas Miguel Hernández . 03202 Alicante, Spain
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Brönnimann B, Meier ML, Hou MY, Parkinson C, Ettlin DA. Novel Air Stimulation MR-Device for Intraoral Quantitative Sensory Cold Testing. Front Hum Neurosci 2016; 10:335. [PMID: 27445771 PMCID: PMC4928459 DOI: 10.3389/fnhum.2016.00335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 06/17/2016] [Indexed: 12/23/2022] Open
Abstract
The advent of neuroimaging in dental research provides exciting opportunities for relating excitation of trigeminal neurons to human somatosensory perceptions. Cold air sensitivity is one of the most frequent causes of dental discomfort or pain. Up to date, devices capable of delivering controlled cold air in an MR-environment are unavailable for quantitative sensory testing. This study therefore aimed at constructing and evaluating a novel MR-compatible, computer-controlled cold air stimulation apparatus (CASA) that produces graded air puffs. CASA consisted of a multi-injector air jet delivery system (AJS), a cold exchanger, a cooling agent, and a stimulus application construction. Its feasibility was tested by performing an fMRI stimulation experiment on a single subject experiencing dentine cold sensitivity. The novel device delivered repetitive, stable air stimuli ranging from room temperature (24.5°C ± 2°C) to -35°C, at flow rates between 5 and 17 liters per minute (l/min). These cold air puffs evoked perceptions similar to natural stimuli. Single-subject fMRI-analysis yielded brain activations typically associated with acute pain processing including thalamus, insular and cingulate cortices, somatosensory, cerebellar, and frontal brain regions. Thus, the novel CASA allowed for controlled, repetitive quantitative sensory testing by using air stimuli at graded temperatures (room temperature down to -35°C) while simultaneously recording brain responses. No MR-compatible stimulation device currently exists that is capable of providing non-contact natural-like stimuli at a wide temperature range to tissues in spatially restricted areas such as the mouth. The physical characteristics of this novel device thus holds promise for advancing the field of trigeminal and spinal somatosensory research, namely with respect to comparing therapeutic interventions for dentine hypersensitivity.
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Affiliation(s)
- Ben Brönnimann
- Pain Research Lab, Center of Dental Medicine, University of Zurich Zurich, Switzerland
| | - Michael L Meier
- Pain Research Lab, Center of Dental Medicine, University of ZurichZurich, Switzerland; Interdisciplinary Spinal Pain Research ISR, Balgrist University HospitalZurich, Switzerland
| | - Mei-Yin Hou
- Pain Research Lab, Center of Dental Medicine, University of Zurich Zurich, Switzerland
| | | | - Dominik A Ettlin
- Pain Research Lab, Center of Dental Medicine, University of Zurich Zurich, Switzerland
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Inflammatory and neuropathic cold allodynia are selectively mediated by the neurotrophic factor receptor GFRα3. Proc Natl Acad Sci U S A 2016; 113:4506-11. [PMID: 27051069 DOI: 10.1073/pnas.1603294113] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tissue injury prompts the release of a number of proalgesic molecules that induce acute and chronic pain by sensitizing pain-sensing neurons (nociceptors) to heat and mechanical stimuli. In contrast, many proalgesics have no effect on cold sensitivity or can inhibit cold-sensitive neurons and diminish cooling-mediated pain relief (analgesia). Nonetheless, cold pain (allodynia) is prevalent in many inflammatory and neuropathic pain settings, with little known of the mechanisms promoting pain vs. those dampening analgesia. Here, we show that cold allodynia induced by inflammation, nerve injury, and chemotherapeutics is abolished in mice lacking the neurotrophic factor receptor glial cell line-derived neurotrophic factor family of receptors-α3 (GFRα3). Furthermore, established cold allodynia is blocked in animals treated with neutralizing antibodies against the GFRα3 ligand, artemin. In contrast, heat and mechanical pain are unchanged, and results show that, in striking contrast to the redundant mechanisms sensitizing other modalities after an insult, cold allodynia is mediated exclusively by a single molecular pathway, suggesting that artemin-GFRα3 signaling can be targeted to selectively treat cold pain.
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Cold and L-menthol-induced sensitization in healthy volunteers--a cold hypersensitivity analogue to the heat/capsaicin model. Pain 2016; 156:880-889. [PMID: 25719613 DOI: 10.1097/j.pain.0000000000000123] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Topical high-concentration L-menthol is the only established human experimental pain model to study mechanisms underlying cold hyperalgesia. We aimed at investigating the combinatorial effect of cold stimuli and topical L-menthol on cold pain and secondary mechanical hyperalgesia. Analogue to the heat-capsaicin model on skin sensitization, we proposed that cold/menthol enhances or prolong L-menthol-evoked sensitization. Topical 40% L-menthol or vehicle was applied (20 minutes) on the volar forearms of 20 healthy females and males (age, 28.7 ± 0.6 years). Cold stimulation of 5°C for 5 minutes was then applied to the treated area 3 times with 40-minute intervals. Cold detection threshold and pain, mechanical hyperalgesia (pinprick), static and dynamic mechanical allodynia (von Frey and brush), skin blood flow (laser speckle), and temperature (thermocamera) were assessed. Cold detection threshold and cold pain threshold (CPT) increased after L-menthol and remained high after the cold rekindling cycles (P < 0.001). L-menthol evoked secondary hyperalgesia to pinprick (P < 0.001) particularly in females (P < 0.05) and also induced secondary allodynia to von Frey and brush (P < 0.001). Application of cold stimuli kept these areas enlarged with a higher response in females to brush after the third cold cycle (P < 0.05). Skin blood flow increased after L-menthol (P < 0.001) and stayed stable after cold cycles. Repeated application of cold on skin treated by L-menthol facilitated and prolonged L-menthol-induced cold pain and hyperalgesia. This model may prove beneficial for testing analgesic compounds when a sufficient duration of time is needed to see drug effects on CPT or mechanical hypersensitivity.
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YOSHIMURA R, NAKAGAWA M, ENDO Y. Cold stimulation evokes exocytotic vesicle release from PC12 cells . Biomed Res 2016; 37:381-383. [DOI: 10.2220/biomedres.37.381] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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63
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Kuzdas-Wood D, Irschick R, Theurl M, Malsch P, Mair N, Mantinger C, Wanschitz J, Klimaschewski L, Poewe W, Stefanova N, Wenning GK. Involvement of Peripheral Nerves in the Transgenic PLP-α-Syn Model of Multiple System Atrophy: Extending the Phenotype. PLoS One 2015; 10:e0136575. [PMID: 26496712 PMCID: PMC4619736 DOI: 10.1371/journal.pone.0136575] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 08/05/2015] [Indexed: 11/18/2022] Open
Abstract
Multiple system atrophy (MSA) is a fatal, rapidly progressive neurodegenerative disease with (oligodendro-)glial cytoplasmic α-synuclein (α-syn) inclusions (GCIs). Peripheral neuropathies have been reported in up to 40% of MSA patients, the cause remaining unclear. In a transgenic MSA mouse model featuring GCI-like inclusion pathology based on PLP-promoter driven overexpression of human α-syn in oligodendroglia motor and non-motor deficits are associated with MSA-like neurodegeneration. Since α-syn is also expressed in Schwann cells we aimed to investigate whether peripheral nerves are anatomically and functionally affected in the PLP-α-syn MSA mouse model.
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Affiliation(s)
- Daniela Kuzdas-Wood
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Tirol, Austria
| | - Regina Irschick
- Department of Anatomy, Histology and Embryology, Division of Clinical and Functional Anatomy, Medical University of Innsbruck, 6020 Innsbruck, Austria
- Department of Anatomy, Histology and Embryology, Division of Neuroanatomy, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Markus Theurl
- Department of Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Tirol, Austria
| | - Philipp Malsch
- Department of Physiology and Medical Physics, Medical University of Innsbruck, Innsbruck, Tirol, Austria
| | - Norbert Mair
- Department of Physiology and Medical Physics, Medical University of Innsbruck, Innsbruck, Tirol, Austria
| | - Christine Mantinger
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Tirol, Austria
| | - Julia Wanschitz
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Tirol, Austria
| | - Lars Klimaschewski
- Department of Anatomy, Histology and Embryology, Division of Clinical and Functional Anatomy, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Tirol, Austria
| | - Nadia Stefanova
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Tirol, Austria
| | - Gregor K. Wenning
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Tirol, Austria
- * E-mail:
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Efficient entry of cell-penetrating peptide nona-arginine into adherent cells involves a transient increase in intracellular calcium. Biochem J 2015; 471:221-30. [PMID: 26272944 PMCID: PMC4613506 DOI: 10.1042/bj20150272] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 08/13/2015] [Indexed: 01/20/2023]
Abstract
Mechanisms by which drug-delivery vehicles based on cationic peptides cross cell membranes remain unknown. We report that an increase in intracellular calcium triggered by temperature drop or high peptide concentrations transiently permeabilizes the plasma membrane for nona-arginine (R9) and delivers it to the cytosol. Understanding the mechanism of entry of cationic peptides such as nona-arginine (R9) into cells remains an important challenge to their use as efficient drug-delivery vehicles. At nanomolar to low micromolar R9 concentrations and at physiological temperature, peptide entry involves endocytosis. In contrast, at a concentration ≥10 μM, R9 induces a very effective non-endocytic entry pathway specific for cationic peptides. We found that a similar entry pathway is induced at 1–2 μM concentrations of R9 if peptide application is accompanied by a rapid temperature drop to 15°C. Both at physiological and at sub-physiological temperatures, this entry mechanism was inhibited by depletion of the intracellular ATP pool. Intriguingly, we found that R9 at 10–20 μM and 37°C induces repetitive spikes in intracellular Ca2+ concentration. This Ca2+ signalling correlated with the efficiency of the peptide entry. Pre-loading cells with the Ca2+ chelator BAPTA (1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid) inhibited both Ca2+ spikes and peptide entry, suggesting that an increase in intracellular Ca2+ precedes and is required for peptide entry. One of the hallmarks of Ca2+ signalling is a transient cell-surface exposure of phosphatidylserine (PS), a lipid normally residing only in the inner leaflet of the plasma membrane. Blocking the accessible PS with the PS-binding domain of lactadherin strongly inhibited non-endocytic R9 entry, suggesting the importance of PS externalization in this process. To conclude, we uncovered a novel mechanistic link between calcium signalling and entry of cationic peptides. This finding will enhance our understanding of the properties of plasma membrane and guide development of future drug-delivery vehicles.
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Aboualizadeh E, Mattson EC, O'Hara CL, Smith AK, Stucky CL, Hirschmugl CJ. Cold shock induces apoptosis of dorsal root ganglion neurons plated on infrared windows. Analyst 2015; 140:4046-56. [PMID: 26000346 PMCID: PMC4536072 DOI: 10.1039/c5an00729a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The chemical status of live sensory neurons is accessible with infrared microspectroscopy of appropriately prepared cells. In this paper, individual dorsal root ganglion (DRG) neurons have been prepared with two different protocols, and plated on glass cover slips, BaF2 and CaF2 substrates. The first protocol exposes the intact DRGs to 4 °C for between 20-30 minutes before dissociating individual neurons and plating 2 hours later. The second protocol maintains the neurons at 23 °C for the entire duration of the sample preparation. The visual appearance of the neurons is similar. The viability was assessed by means of trypan blue exclusion method to determine the viability of the neurons. The neurons prepared under the first protocol (cold exposure) and plated on BaF2 reveal a distinct chemical signature and chemical distribution that is different from the other sample preparations described in the paper. Importantly, results for other sample preparation methods, using various substrates and temperature protocols, when compared across the overlapping spectral bandwidth, present normal chemical distribution within the neurons. The unusual chemically specific spatial variation is dominated by a lack of protein and carbohydrates in the center of the neurons and signatures of unraveling DNA are detected. We suggest that cold shock leads to apoptosis of DRGs, followed by osmotic stress originating from ion gradients across the cell membrane leading to cell lysis.
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Affiliation(s)
- Ebrahim Aboualizadeh
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211 USA.
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66
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Tominaga M, Takayama Y. Interaction between TRP and Ca2+-activated chloride channels. Channels (Austin) 2015; 8:178-9. [PMID: 24770344 PMCID: PMC5210169 DOI: 10.4161/chan.29001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
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Andrews MD, af Forselles K, Beaumont K, Galan SRG, Glossop PA, Grenie M, Jessiman A, Kenyon AS, Lunn G, Maw G, Owen RM, Pryde DC, Roberts D, Tran TD. Discovery of a Selective TRPM8 Antagonist with Clinical Efficacy in Cold-Related Pain. ACS Med Chem Lett 2015; 6:419-24. [PMID: 25893043 DOI: 10.1021/ml500479v] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 01/30/2015] [Indexed: 12/11/2022] Open
Abstract
The transient receptor potential (TRP) family of ion channels comprises nonselective cation channels that respond to a wide range of chemical and thermal stimuli. TRPM8, a member of the melastatin subfamily, is activated by cold temperatures (<28 °C), and antagonists of this channel have the potential to treat cold induced allodynia and hyperalgesia. However, TRPM8 has also been implicated in mammalian thermoregulation and antagonists have the potential to induce hypothermia in patients. We report herein the identification and optimization of a series of TRPM8 antagonists that ultimately led to the discovery of PF-05105679. The clinical finding with this compound will be discussed, including both efficacy and its ability to affect thermoregulation processes in humans.
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Affiliation(s)
| | | | - Kevin Beaumont
- Pharmacokinetics,
Dynamics and Metabolism, Pfizer Worldwide Research and Development, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | | | | | | | | | | | | | | | - Robert M. Owen
- Worldwide
Medicinal Chemistry, Pfizer Neusentis, Granta Park, Cambridge CB21 6GS, United Kingdom
| | - David C. Pryde
- Worldwide
Medicinal Chemistry, Pfizer Neusentis, Granta Park, Cambridge CB21 6GS, United Kingdom
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Drew KL, Romanovsky AA, Stephen TKL, Tupone D, Williams RH. Future approaches to therapeutic hypothermia: a symposium report. Temperature (Austin) 2015; 2:168-71. [PMID: 27227020 PMCID: PMC4843898 DOI: 10.4161/23328940.2014.976512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 10/09/2014] [Accepted: 10/09/2014] [Indexed: 12/22/2022] Open
Key Words
- A1AR
- AGS, arctic ground squirrel
- CE, capillary electrophoresis
- EEG,electroencephalogram
- FSCV, Fast scan cyclic voltammetry
- HPLC, high performance liquid chromatography
- ICV, intracerebroventricular
- TRPM8
- Tb, core body temperature
- adenosine
- capillary electrophoresis
- hibernation
- nNOS, neuronal nitric oxide synthase; NTS, nucleus tractus solitarii; TH, therapeutic hypothermia; TRP, transient receptor potential [channel(s)]; TRPM8, TRP melastatin-8
- nNOS/NK1
- targeted temperature management
- therapeutic hypothermia
- torpor
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Affiliation(s)
- Kelly L Drew
- Institute of Arctic Biology; University of Alaska Fairbanks; Fairbanks, AK, USA
| | - Andrej A Romanovsky
- Systemic Inflammation Laboratory (Fever Lab); Trauma Research, St. Joseph's Hospital and Medical Center; Phoenix, AZ, USA
| | - Terilyn KL Stephen
- Department of Chemistry and Biochemistry; University of Alaska Fairbanks; Fairbanks, AK, USA
| | - Domenico Tupone
- Department of Neurological Surgery; Oregon Health & Science University; Portland, OR, USA
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Reinach PS, Chen W, Mergler S. Polymodal roles of transient receptor potential channels in the control of ocular function. EYE AND VISION 2015; 2:5. [PMID: 26605361 PMCID: PMC4655450 DOI: 10.1186/s40662-015-0016-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 02/15/2015] [Indexed: 12/05/2022]
Abstract
Maintenance of intracellular Ca2+ levels at orders of magnitude below those in the extracellular environment is a requisite for preserving cell viability. Membrane channels contribute to such control through modulating their time-dependent opening and closing behaviour. Such regulation requires Ca2+ to serve as a second messenger mediating receptor control of numerous life-sustaining responses. Transient receptor potential (TRP) channels signal transduce a wide variety of different sensory stimuli to induce responses modulating cellular function. These channels are non-selective cation channels with variable Ca2+ selectivity having extensive sequence homology. They constitute a superfamily made up of 28 different members that are subdivided into 7 different subfamilies based on differences in sequence homology. Some of these TRP channel isotypes are expressed in the eye and localized to both neuronal and non-neuronal cell membranes. Their activation generates intracellular Ca2+ transients and other downstream-linked signalling events that affect numerous responses required for visual function. As there is an association between changes in functional TRP expression in various ocular diseases, there are efforts underway to determine if these channels can be used as drug targets to reverse declines in ocular function. We review here our current knowledge about the expression, function and regulation of TRPs in different eye tissues in health and disease. Furthermore, some of the remaining hurdles are described to developing safe and efficacious TRP channel modulators for use in a clinical setting.
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Affiliation(s)
- Peter S Reinach
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325027 P.R. China
| | - Weiwei Chen
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325027 P.R. China
| | - Stefan Mergler
- Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Klinik für Augenheilkunde, Augustenburger Platz 1, D-13353 Berlin, Germany
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Laursen WJ, Anderson EO, Hoffstaetter LJ, Bagriantsev SN, Gracheva EO. Species-specific temperature sensitivity of TRPA1. Temperature (Austin) 2015; 2:214-26. [PMID: 27227025 PMCID: PMC4843866 DOI: 10.1080/23328940.2014.1000702] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 12/16/2014] [Accepted: 12/16/2014] [Indexed: 11/25/2022] Open
Abstract
Transient receptor potential ankyrin 1 (TRPA1) is a polymodal ion channel sensitive to temperature and chemical stimuli. The importance of temperature and aversive chemical detection for survival has driven the evolutionary diversity of TRPA1 sensitivity. This diversity can be observed in the various roles of TRPA1 in different species, where it is proposed to act as a temperature-insensitive chemosensor, a heat transducer, a noxious cold transducer, or a detector of low-intensity heat for prey localization. Exploring the variation of TRPA1 functions among species provides evolutionary insight into molecular mechanisms that fine-tune thermal and chemical sensitivity, and offers an opportunity to address basic principles of temperature gating in ion channels. A decade of research has yielded a number of hypotheses describing physiological roles of TRPA1, modulators of its activity, and biophysical principles of gating. This review surveys the diversity of TRPA1 adaptations across evolutionary taxa and explores possible mechanisms of TRPA1 activation.
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Affiliation(s)
- Willem J Laursen
- Department of Cellular and Molecular Physiology; Yale University School of Medicine; New Haven, CT, USA; Program in Cellular Neuroscience; Neurodegeneration and Repair; Yale University School of Medicine; New Haven, CT, USA
| | - Evan O Anderson
- Department of Cellular and Molecular Physiology; Yale University School of Medicine ; New Haven, CT, USA
| | - Lydia J Hoffstaetter
- Department of Cellular and Molecular Physiology; Yale University School of Medicine; New Haven, CT, USA; Program in Cellular Neuroscience; Neurodegeneration and Repair; Yale University School of Medicine; New Haven, CT, USA
| | - Sviatoslav N Bagriantsev
- Department of Cellular and Molecular Physiology; Yale University School of Medicine ; New Haven, CT, USA
| | - Elena O Gracheva
- Department of Cellular and Molecular Physiology; Yale University School of Medicine; New Haven, CT, USA; Program in Cellular Neuroscience; Neurodegeneration and Repair; Yale University School of Medicine; New Haven, CT, USA
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71
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Abstract
The ability of the body to perceive noxious stimuli lies in a heterogeneous group of primary somatosensory neurons termed nociceptors. The molecular receptors of noxious mechanical, temperature, or chemical stimuli are expressed in these neurons and have drawn considerable attention as possible targets for analgesic development to improve treatment for the millions who suffer from chronic pain conditions. A number of thermoTRPs, a subset of the transient receptor potential family of ion channels, are activated by a wide range on noxious stimuli. In this review, we review the function of these channels and examine the evidence that thermoTRPs play a vital role in acute, inflammatory and neuropathic nociception.
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Affiliation(s)
- Robyn J Laing
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Ajay Dhaka
- Department of Biological Structure, University of Washington, Seattle, WA, USA
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Ezenwa MO, Molokie RE, Wang ZJ, Yao Y, Suarez ML, Pullum C, Schlaeger JM, Fillingim RB, Wilkie DJ. Safety and Utility of Quantitative Sensory Testing among Adults with Sickle Cell Disease: Indicators of Neuropathic Pain? Pain Pract 2015; 16:282-93. [PMID: 25581383 DOI: 10.1111/papr.12279] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/27/2014] [Accepted: 11/18/2014] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Pain is the hallmark symptom of sickle cell disease (SCD), yet the types of pain that these patients experience, and the underlying mechanisms, have not been well characterized. The study purpose was to determine the safety and utility of a mechanical and thermal quantitative sensory testing (QST) protocol and the feasibility of utilizing neuropathic pain questionnaires among adults with SCD. METHODS A convenience sample (N = 25, 18 women, mean age 38.5 ± 12.5 [20-58 years]) completed self-report pain and quality-of-life tools. Subjects also underwent testing with the TSA-II NeuroSensory Analyzer and calibrated von Frey microfilaments. RESULTS We found that the QST protocol was safe and did not stimulate a SCD pain crisis. There was evidence of central sensitization (n = 15), peripheral sensitization (n = 1), a mix of central and peripheral sensitization (n = 8), or no sensitization (n = 1). The neuropathic pain self-report tools were feasible with evidence of construct validity; 40% of the subjects reported S-LANSS scores that were indicative of neuropathic pain and had evidence of central, peripheral or mixed sensitization. DISCUSSION The QST protocol can be safely conducted in adults with SCD and provides evidence of central or peripheral sensitization, which is consistent with a neuropathic component to SCD pain. These findings are novel, warrant a larger confirmatory study, and indicate the need for normative QST data from African American adults and older adults.
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Affiliation(s)
- Miriam O Ezenwa
- University of Illinois at Chicago, College of Nursing Department of Biobehavioral Health Science, Chicago, Illinois, U.S.A.,University of Illinois at Chicago, Comprehensive Sickle Cell Center, Chicago, Illinois, U.S.A
| | - Robert E Molokie
- University of Illinois at Chicago, Comprehensive Sickle Cell Center, Chicago, Illinois, U.S.A.,College of Medicine, College of Pharmacy, Jesse Brown VA Medical Center, Chicago, Illinois, U.S.A
| | - Zaijie Jim Wang
- University of Illinois at Chicago, Comprehensive Sickle Cell Center, Chicago, Illinois, U.S.A.,Department of Biopharmaceutical Sciences and Cancer Center, University of Illinois at Chicago, Chicago, Illinois, U.S.A
| | - Yingwei Yao
- University of Illinois at Chicago, College of Nursing Department of Biobehavioral Health Science, Chicago, Illinois, U.S.A.,University of Illinois at Chicago, Center of Excellence for End-of-Life Transition Research, Chicago, Illinois, U.S.A
| | - Marie L Suarez
- University of Illinois at Chicago, College of Nursing Department of Biobehavioral Health Science, Chicago, Illinois, U.S.A
| | - Cherese Pullum
- University of Illinois at Chicago, College of Nursing Department of Biobehavioral Health Science, Chicago, Illinois, U.S.A
| | - Judith M Schlaeger
- University of Illinois at Chicago, College of Nursing Department of Biobehavioral Health Science, Chicago, Illinois, U.S.A
| | - Roger B Fillingim
- College of Dentistry, Pain Research and Intervention Center of Excellence, University of Florida, Gainesville, Florida, U.S.A
| | - Diana J Wilkie
- University of Illinois at Chicago, College of Nursing Department of Biobehavioral Health Science, Chicago, Illinois, U.S.A.,University of Illinois at Chicago, Comprehensive Sickle Cell Center, Chicago, Illinois, U.S.A.,University of Illinois at Chicago, Center of Excellence for End-of-Life Transition Research, Chicago, Illinois, U.S.A
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Abstract
During exposure to cold, our bodies attempt to maintain normal core temperature by restricting heat loss through cutaneous vasoconstriction, and by increasing heat production through shivering and nonshivering thermogenesis. In selected areas of human skin (including on the fingers and toes), the vascular system has specialized structural and functional features that enable it to contribute to thermoregulation. These features include arteriovenous anastomoses, which directly connect the arterial and venous systems and bypass the nutritional capillaries supplying blood to the skin tissue. Of note, Raynaud phenomenon predominantly affects the arterial territories supplying these specialized areas of skin. Indeed, Raynaud phenomenon can be considered a disorder of vascular thermoregulatory control. This Review presents an understanding of Raynaud phenomenon in the context of vascular and thermoregulatory control mechanisms, including the role of unique thermosensitive vascular structural and functional specialization, and describes the potential role of thermogenesis in this disorder. This new approach provides remarkable insight into the disease process and builds a framework to critically appraise the existing knowledge base. This paradigm also explains the deficiencies in some current therapeutic approaches, and highlights new areas of potential relevance to the pathogenesis and treatment of Raynaud phenomenon that should be expanded and explored.
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74
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Allodynia and hyperalgesia in neuropathic pain: clinical manifestations and mechanisms. Lancet Neurol 2014; 13:924-35. [PMID: 25142459 DOI: 10.1016/s1474-4422(14)70102-4] [Citation(s) in RCA: 516] [Impact Index Per Article: 51.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Allodynia (pain due to a stimulus that does not usually provoke pain) and hyperalgesia (increased pain from a stimulus that usually provokes pain) are prominent symptoms in patients with neuropathic pain. Both are seen in various peripheral neuropathies and central pain disorders, and affect 15-50% of patients with neuropathic pain. Allodynia and hyperalgesia are classified according to the sensory modality (touch, pressure, pinprick, cold, and heat) that is used to elicit the sensation. Peripheral sensitisation and maladaptive central changes contribute to the generation and maintenance of these reactions, with separate mechanisms in different subtypes of allodynia and hyperalgesia. Pain intensity and relief are important measures in clinical pain studies, but might be insufficient to capture the complexity of the pain experience. Better understanding of allodynia and hyperalgesia might provide clues to the underlying pathophysiology of neuropathic pain and, as such, they represent new or additional endpoints in pain trials.
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75
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Caterina MJ. TRP channel cannabinoid receptors in skin sensation, homeostasis, and inflammation. ACS Chem Neurosci 2014; 5:1107-16. [PMID: 24915599 PMCID: PMC4240254 DOI: 10.1021/cn5000919] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
![]()
In
the skin, cannabinoid lipids, whether of endogenous or exogenous
origin, are capable of regulating numerous sensory, homeostatic, and
inflammatory events. Although many of these effects are mediated by
metabotropic cannabinoid receptors, a growing body of evidence has
revealed that multiple members of the transient receptor potential
(TRP) ion channel family can act as “ionotropic cannabinoid
receptors”. Furthermore, many of these same TRP channels are
intimately involved in cutaneous processes that include the initiation
of pain, temperature, and itch perception, the maintenance of epidermal
homeostasis, the regulation of hair follicles and sebaceous glands,
and the modulation of dermatitis. Ionotropic cannabinoid receptors
therefore represent potentially attractive targets for the therapeutic
use of cannabinoids to treat sensory and dermatological diseases.
Furthermore, the interactions between neurons and other cell types
that are mediated by cutaneous ionotropic cannabinoid receptors are
likely to be recapitulated during physiological and pathophysiological
processes in the central nervous system and elsewhere, making the
skin an ideal setting in which to dissect general complexities of
cannabinoid signaling.
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Affiliation(s)
- Michael J. Caterina
- Departments of Neurosurgery,
Biological Chemistry, and Neuroscience, Neurosurgery Pain Research
Institute, Center for Sensory Biology, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, Maryland 21205, United States
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Raddatz N, Castillo JP, Gonzalez C, Alvarez O, Latorre R. Temperature and voltage coupling to channel opening in transient receptor potential melastatin 8 (TRPM8). J Biol Chem 2014; 289:35438-54. [PMID: 25352597 DOI: 10.1074/jbc.m114.612713] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Expressed in somatosensory neurons of the dorsal root and trigeminal ganglion, the transient receptor potential melastatin 8 (TRPM8) channel is a Ca(2+)-permeable cation channel activated by cold, voltage, phosphatidylinositol 4,5-bisphosphate, and menthol. Although TRPM8 channel gating has been characterized at the single channel and macroscopic current levels, there is currently no consensus regarding the extent to which temperature and voltage sensors couple to the conduction gate. In this study, we extended the range of voltages where TRPM8-induced ionic currents were measured and made careful measurements of the maximum open probability the channel can attain at different temperatures by means of fluctuation analysis. The first direct measurements of TRPM8 channel temperature-driven conformational rearrangements provided here suggest that temperature alone is able to open the channel and that the opening reaction is voltage-independent. Voltage is a partial activator of TRPM8 channels, because absolute open probability values measured with fully activated voltage sensors are less than 1, and they decrease as temperature rises. By unveiling the fast temperature-dependent deactivation process, we show that TRPM8 channel deactivation is well described by a double exponential time course. The fast and slow deactivation processes are temperature-dependent with enthalpy changes of 27.2 and 30.8 kcal mol(-1). The overall Q10 for the closing reaction is about 33. A three-tiered allosteric model containing four voltage sensors and four temperature sensors can account for the complex deactivation kinetics and coupling between voltage and temperature sensor activation and channel opening.
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Affiliation(s)
- Natalia Raddatz
- From the Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103 and
| | - Juan P Castillo
- From the Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103 and
| | - Carlos Gonzalez
- From the Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103 and
| | - Osvaldo Alvarez
- From the Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103 and the Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile
| | - Ramon Latorre
- From the Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103 and
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Goswami SC, Mishra SK, Maric D, Kaszas K, Gonnella GL, Clokie SJ, Kominsky HD, Gross JR, Keller JM, Mannes AJ, Hoon MA, Iadarola MJ. Molecular signatures of mouse TRPV1-lineage neurons revealed by RNA-Seq transcriptome analysis. THE JOURNAL OF PAIN 2014; 15:1338-1359. [PMID: 25281809 DOI: 10.1016/j.jpain.2014.09.010] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/10/2014] [Accepted: 09/19/2014] [Indexed: 12/22/2022]
Abstract
UNLABELLED Disorders of pain neural systems are frequently chronic and, when recalcitrant to treatment, can severely degrade the quality of life. The pain pathway begins with sensory neurons in dorsal root or trigeminal ganglia, and the neuronal subpopulations that express the transient receptor potential cation channel, subfamily V, member 1 (TRPV1) ion channel transduce sensations of painful heat and inflammation and play a fundamental role in clinical pain arising from cancer and arthritis. In the present study, we elucidate the complete transcriptomes of neurons from the TRPV1 lineage and a non-TRPV1 neuroglial population in sensory ganglia through the combined application of next-gen deep RNA-Seq, genetic neuronal labeling with fluorescence-activated cell sorting, or neuron-selective chemoablation. RNA-Seq accurately quantitates gene expression, a difficult parameter to determine with most other methods, especially for very low and very high expressed genes. Differentially expressed genes are present at every level of cellular function from the nucleus to the plasma membrane. We identified many ligand receptor pairs in the TRPV1 population, suggesting that autonomous presynaptic regulation may be a major regulatory mechanism in nociceptive neurons. The data define, in a quantitative, cell population-specific fashion, the molecular signature of a distinct and clinically important group of pain-sensing neurons and provide an overall framework for understanding the transcriptome of TRPV1 nociceptive neurons. PERSPECTIVE Next-gen RNA-Seq, combined with molecular genetics, provides a comprehensive and quantitative measurement of transcripts in TRPV1 lineage neurons and a contrasting transcriptome from non-TRPV1 neurons and cells. The transcriptome highlights previously unrecognized protein families, identifies multiple molecular circuits for excitatory or inhibitory autocrine and paracrine signaling, and suggests new combinatorial approaches to pain control.
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Affiliation(s)
- Samridhi C Goswami
- Anesthesia Section, Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Santosh K Mishra
- Molecular Genetics Unit, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research, Bethesda, Maryland
| | - Dragan Maric
- Laboratory of Neurophysiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Krisztian Kaszas
- Anesthesia Section, Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Gian Luigi Gonnella
- Anesthesia Section, Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Samuel J Clokie
- Anesthesia Section, Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Hal D Kominsky
- Anesthesia Section, Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Jacklyn R Gross
- Anesthesia Section, Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Jason M Keller
- Anesthesia Section, Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Andrew J Mannes
- Anesthesia Section, Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Mark A Hoon
- Molecular Genetics Unit, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research, Bethesda, Maryland
| | - Michael J Iadarola
- Anesthesia Section, Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland.
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78
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A somatosensory circuit for cooling perception in mice. Nat Neurosci 2014; 17:1560-6. [PMID: 25262494 DOI: 10.1038/nn.3828] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/03/2014] [Indexed: 12/14/2022]
Abstract
The temperature of an object provides important somatosensory information for animals performing tactile tasks. Humans can perceive skin cooling of less than one degree, but the sensory afferents and central circuits that they engage to enable the perception of surface temperature are poorly understood. To address these questions, we examined the perception of glabrous skin cooling in mice. We found that mice were also capable of perceiving small amplitude skin cooling and that primary somatosensory (S1) cortical neurons were required for cooling perception. Moreover, the absence of the menthol-gated transient receptor potential melastatin 8 ion channel in sensory afferent fibers eliminated the ability to perceive cold and the corresponding activation of S1 neurons. Our results identify parts of a neural circuit underlying cold perception in mice and provide a new model system for the analysis of thermal processing and perception and multimodal integration.
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79
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Le Pichon CE, Chesler AT. The functional and anatomical dissection of somatosensory subpopulations using mouse genetics. Front Neuroanat 2014; 8:21. [PMID: 24795573 PMCID: PMC4001001 DOI: 10.3389/fnana.2014.00021] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 03/24/2014] [Indexed: 11/13/2022] Open
Abstract
The word somatosensation comes from joining the Greek word for body (soma) with a word for perception (sensation). Somatosensory neurons comprise the largest sensory system in mammals and have nerve endings coursing throughout the skin, viscera, muscle, and bone. Their cell bodies reside in a chain of ganglia adjacent to the dorsal spinal cord (the dorsal root ganglia) and at the base of the skull (the trigeminal ganglia). While the neuronal cell bodies are intermingled within the ganglia, the somatosensory system is in reality composed of numerous sub-systems, each specialized to detect distinct stimuli, such as temperature and touch. Historically, somatosensory neurons have been classified using a diverse host of anatomical and physiological parameters, such as the size of the cell body, degree of myelination, histological labeling with markers, specialization of the nerve endings, projection patterns in the spinal cord and brainstem, receptive tuning, and conduction velocity of their action potentials. While useful, the picture that emerged was one of heterogeneity, with many markers at least partially overlapping. More recently, by capitalizing on advances in molecular techniques, researchers have identified specific ion channels and sensory receptors expressed in subsets of sensory neurons. These studies have proved invaluable as they allow genetic access to small subsets of neurons for further molecular dissection. Data being generated from transgenic mice favor a model whereby an array of dedicated neurons is responsible for selectively encoding different modalities. Here we review the current knowledge of the different sensory neuron subtypes in the mouse, the markers used to study them, and the neurogenetic strategies used to define their anatomical projections and functional roles.
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Affiliation(s)
- Claire E. Le Pichon
- National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesda, MD, USA
| | - Alexander T. Chesler
- Intramural Pain Program, Section on Sensory Cells and Circuits, National Center for Complementary and Alternative Medicine, National Institutes of HealthBethesda, MD, USA
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80
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Anderson EM, Jenkins AC, Caudle RM, Neubert JK. The effects of a co-application of menthol and capsaicin on nociceptive behaviors of the rat on the operant orofacial pain assessment device. PLoS One 2014; 9:e89137. [PMID: 24558480 PMCID: PMC3928399 DOI: 10.1371/journal.pone.0089137] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 01/20/2014] [Indexed: 01/04/2023] Open
Abstract
Background Transient receptor potential (TRP) cation channels are involved in the perception of hot and cold pain and are targets for pain relief in humans. We hypothesized that agonists of TRPV1 and TRPM8/TRPA1, capsaicin and menthol, would alter nociceptive behaviors in the rat, but their opposite effects on temperature detection would attenuate one another if combined. Methods Rats were tested on the Orofacial Pain Assessment Device (OPAD, Stoelting Co.) at three temperatures within a 17 min behavioral session (33°C, 21°C, 45°C). Results The lick/face ratio (L/F: reward licking events divided by the number of stimulus contacts. Each time there is a licking event a contact is being made.) is a measure of nociception on the OPAD and this was equally reduced at 45°C and 21°C suggesting they are both nociceptive and/or aversive to rats. However, rats consumed (licks) equal amounts at 33°C and 21°C but less at 45°C suggesting that heat is more nociceptive than cold at these temperatures in the orofacial pain model. When menthol and capsaicin were applied alone they both induced nociceptive behaviors like lower L/F ratios and licks. When applied together though, the licks at 21°C were equal to those at 33°C and both were significantly higher than at 45°C. Conclusions This suggests that the cool temperature is less nociceptive when TRPM8/TRPA1 and TRPV1 are co-activated. These results suggest that co-activation of TRP channels can reduce certain nociceptive behaviors. These data demonstrate that the motivational aspects of nociception can be influenced selectively by TRP channel modulation and that certain aspects of pain can be dissociated and therefore targeted selectively in the clinic.
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Affiliation(s)
- Ethan M. Anderson
- Department of Oral and Maxillofacial Surgery, University of Florida College of Dentistry, Gainesville, Florida, United States of America
- Department of Neuroscience, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, Florida, United States of America
- * E-mail:
| | - Alan C. Jenkins
- Department of Orthodontics, University of Florida, Gainesville, Florida, United States of America
| | - Robert M. Caudle
- Department of Oral and Maxillofacial Surgery, University of Florida College of Dentistry, Gainesville, Florida, United States of America
- Department of Neuroscience, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, Florida, United States of America
| | - John K. Neubert
- Department of Orthodontics, University of Florida, Gainesville, Florida, United States of America
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81
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Patel R, Gonçalves L, Newman R, Jiang FL, Goldby A, Reeve J, Hendrick A, Teall M, Hannah D, Almond S, Brice N, Dickenson AH. Novel TRPM8 antagonist attenuates cold hypersensitivity after peripheral nerve injury in rats. J Pharmacol Exp Ther 2014; 349:47-55. [PMID: 24472724 DOI: 10.1124/jpet.113.211243] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Abnormal cold sensitivity is a common feature of a range of neuropathies. In the murine somatosensory system, multiple aspects of cold sensitivity are dependent on TRPM8, both short term and in response to peripheral nerve injury. The specialized nature of cold-sensitive afferents and the restricted expression of TRPM8 render it an attractive target for the treatment of cold hypersensitivity. This current study examines the effect of a novel TRPM8 antagonist (M8-An) in naive and spinal nerve-ligated rats through behavioral and in vivo electrophysiological approaches. In vitro, M8-An inhibited icilin-evoked Ca(2+) currents in HEK293 cells stably expressing human TRPM8 with an IC(50) of 10.9 nM. In vivo, systemic M8-An transiently decreased core body temperature. Deep dorsal horn recordings were made in vivo from neurons innervating the hind paw. M8-An inhibited neuronal responses to innocuous and noxious cooling of the receptive field in spinal nerve-ligated rats but not in naive rats. No effect on neuronal responses to mechanical and heat stimulation was observed. In addition, M8-An also attenuated behavioral responses to cold but not mechanical stimulation after nerve ligation without affecting the uninjured contralateral response. The data presented here support a contribution of TRPM8 to the pathophysiology of cold hypersensitivity in this model and highlight the potential of the pharmacological block of TRPM8 in alleviating the associated symptoms.
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Affiliation(s)
- Ryan Patel
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom (R.P., L.G., A.H.D.); Takeda Cambridge Ltd, Cambridge, United Kingdom (R.N., A.G., J.R., A.H., M.T., D.H., S.A., N.B.); and Takeda Singapore Pte Ltd, Chromos, Singapore (F.L.J.)
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82
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Cohen MR, Moiseenkova-Bell VY. Structure of thermally activated TRP channels. CURRENT TOPICS IN MEMBRANES 2014; 74:181-211. [PMID: 25366237 DOI: 10.1016/b978-0-12-800181-3.00007-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Temperature sensation is important for adaptation and survival of organisms. While temperature has the potential to affect all biological macromolecules, organisms have evolved specific thermosensitive molecular detectors that are able to transduce temperature changes into physiologically relevant signals. Among these thermosensors are ion channels from the transient receptor potential (TRP) family. Prime candidates include TRPV1-4, TRPA1, and TRPM8 (the so-called "thermoTRP" channels), which are expressed in sensory neurons and gated at specific temperatures. Electrophysiological and thermodynamic approaches have been employed to determine the nature by which thermoTRPs detect temperature and couple temperature changes to channel gating. To further understand how thermoTRPs sense temperature, high-resolution structures of full-length thermoTRPs channels will be required. Here, we will discuss current progress in unraveling the structures of thermoTRP channels.
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Affiliation(s)
- Matthew R Cohen
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Vera Y Moiseenkova-Bell
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
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83
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Laursen WJ, Bagriantsev SN, Gracheva EO. TRPA1 channels: chemical and temperature sensitivity. CURRENT TOPICS IN MEMBRANES 2014; 74:89-112. [PMID: 25366234 DOI: 10.1016/b978-0-12-800181-3.00004-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Transient receptor potential ankyrin 1 (TRPA1) is a polymodal excitatory ion channel found in sensory neurons of different organisms, ranging from worms to humans. Since its discovery as an uncharacterized transmembrane protein in human fibroblasts, TRPA1 has become one of the most intensively studied ion channels. Its function has been linked to regulation of heat and cold perception, mechanosensitivity, hearing, inflammation, pain, circadian rhythms, chemoreception, and other processes. Some of these proposed functions remain controversial, while others have gathered considerable experimental support. A truly polymodal ion channel, TRPA1 is activated by various stimuli, including electrophilic chemicals, oxygen, temperature, and mechanical force, yet the molecular mechanism of TRPA1 gating remains obscure. In this review, we discuss recent advances in the understanding of TRPA1 physiology, pharmacology, and molecular function.
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Affiliation(s)
- Willem J Laursen
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, USA
| | - Sviatoslav N Bagriantsev
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Elena O Gracheva
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, USA
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84
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Madrid R, Pertusa M. Intimacies and physiological role of the polymodal cold-sensitive ion channel TRPM8. CURRENT TOPICS IN MEMBRANES 2014; 74:293-324. [PMID: 25366241 DOI: 10.1016/b978-0-12-800181-3.00011-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The detection of environmental temperature is critical for the survival of the most diverse organisms. Thermosensitive transient receptor potential (thermoTRP) channels have evolved as a class of ion channels activated by a wide range of temperatures. These molecular thermal sensors are spread through the different TRP channel subfamilies. Among the Melastatin subfamily of TRP channels, the eighth member, TRPM8, is a calcium-permeable cationic ion channel activated by cold, by substances that evoke cold sensation such as menthol, and by voltage. This channel is considered the main molecular entity responsible for the sensitivity to cold of primary sensory neurons of the somatosensory system. Here we present to the readers a summary of some the most relevant biophysical properties, physiological role, and molecular intimacies of this polymodal thermoTRP channel.
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Affiliation(s)
- Rodolfo Madrid
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - María Pertusa
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
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85
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Yang FC, Tan T, Huang T, Christianson J, Samad OA, Liu Y, Roberson D, Davis BM, Ma Q. Genetic control of the segregation of pain-related sensory neurons innervating the cutaneous versus deep tissues. Cell Rep 2013; 5:1353-64. [PMID: 24316076 DOI: 10.1016/j.celrep.2013.11.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 09/28/2013] [Accepted: 11/04/2013] [Indexed: 12/30/2022] Open
Abstract
Mammalian pain-related sensory neurons are derived from TrkA lineage neurons located in the dorsal root ganglion. These neurons project to peripheral targets throughout the body, which can be divided into superficial and deep tissues. Here, we find that the transcription factor Runx1 is required for the development of many epidermis-projecting TrkA lineage neurons. Accordingly, knockout of Runx1 leads to the selective loss of sensory innervation to the epidermis, whereas deep tissue innervation and two types of deep tissue pain are unaffected. Within these cutaneous neurons, Runx1 suppresses a large molecular program normally associated with sensory neurons that innervate deep tissues, such as muscle and visceral organs. Ectopic expression of Runx1 in these deep sensory neurons causes a loss of this molecular program and marked deficits in deep tissue pain. Thus, this study provides insight into a genetic program controlling the segregation of cutaneous versus deep tissue pain pathways.
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Affiliation(s)
- Fu-Chia Yang
- Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA
| | - Taralyn Tan
- Department of Neurobiology, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA
| | - Tianwen Huang
- Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA
| | - Julie Christianson
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
| | - Omar A Samad
- Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA
| | - Yang Liu
- Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA
| | - David Roberson
- Department of Neurobiology, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA
| | - Brian M Davis
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
| | - Qiufu Ma
- Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02115, USA.
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86
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Artemin, a glial cell line-derived neurotrophic factor family member, induces TRPM8-dependent cold pain. J Neurosci 2013; 33:12543-52. [PMID: 23884957 DOI: 10.1523/jneurosci.5765-12.2013] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chronic pain associated with injury or disease can result from dysfunction of sensory afferents whereby the threshold for activation of pain-sensing neurons (nociceptors) is lowered. Neurotrophic factors control nociceptor development and survival, but also induce sensitization through activation of their cognate receptors, attributable, in part, to the modulation of ion channel function. Thermal pain is mediated by channels of the transient receptor potential (TRP) family, including the cold and menthol receptor TRPM8. Although it has been shown that TRPM8 is involved in cold hypersensitivity, the molecular mechanisms underlying this pain modality are unknown. Using microarray analyses to identify mouse genes enriched in TRPM8 neurons, we found that the glial cell line-derived neurotrophic factor (GDNF) family receptor GFRα3 is expressed in a subpopulation of TRPM8 sensory neurons that have the neurochemical profile of cold nociceptors. Moreover, we found that artemin, the specific GFRα3 ligand that evokes heat hyperalgesia, robustly sensitized cold responses in a TRPM8-dependent manner in mice. In contrast, GFRα1 and GFRα2 are not coexpressed with TRPM8 and their respective ligands GDNF and neurturin did not induce cold pain, whereas they did evoke heat hyperalgesia. Nerve growth factor induced mild cold sensitization, consistent with TrkA expression in TRPM8 neurons. However, bradykinin failed to alter cold sensitivity even though its receptor expresses in a subset of TRPM8 neurons. These results show for the first time that only select neurotrophic factors induce cold sensitization through TRPM8 in vivo, unlike the broad range of proalgesic agents capable of promoting heat hyperalgesia.
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87
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Filingeri D, Redortier B, Hodder S, Havenith G. The role of decreasing contact temperatures and skin cooling in the perception of skin wetness. Neurosci Lett 2013; 551:65-9. [PMID: 23886487 DOI: 10.1016/j.neulet.2013.07.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 07/02/2013] [Accepted: 07/08/2013] [Indexed: 12/19/2022]
Abstract
Cold sensations are suggested as the primary inducer of the perception of skin wetness. However, limited data are available on the effects of skin cooling. Hence, we investigated the role of peripheral cold afferents in the perception of wetness. Six cold-dry stimuli (producing skin cooling rates in a range of 0.02-0.41°C/s) were applied on the forearm of 9 female participants. Skin temperature and conductance, thermal and wetness perception were recorded. Five out of 9 participants perceived wetness as a result of cold-dry stimuli with cooling rates in a range of 0.14-0.41°C/s, while 4 did not perceive skin wetness at all. Although skin cooling and cold sensations play a role in evoking the perception of wetness, these are not always of a primary importance and other sensory modalities (i.e. touch and vision), as well as the inter-individual variability in thermal sensitivity, might be equally determinant in characterising this perception.
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Affiliation(s)
- Davide Filingeri
- Environmental Ergonomics Research Centre, Loughborough Design School, Loughborough University, Loughborough LE11 3TU, UK.
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88
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TRPM8 is the principal mediator of menthol-induced analgesia of acute and inflammatory pain. Pain 2013; 154:2169-2177. [PMID: 23820004 DOI: 10.1016/j.pain.2013.06.043] [Citation(s) in RCA: 182] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/17/2013] [Accepted: 06/26/2013] [Indexed: 11/20/2022]
Abstract
Menthol, the cooling natural product of peppermint, is widely used in medicinal preparations for the relief of acute and inflammatory pain in sports injuries, arthritis, and other painful conditions. Menthol induces the sensation of cooling by activating TRPM8, an ion channel in cold-sensitive peripheral sensory neurons. Recent studies identified additional targets of menthol, including the irritant receptor, TRPA1, voltage-gated ion channels and neurotransmitter receptors. It remains unclear which of these targets contribute to menthol-induced analgesia, or to the irritating side effects associated with menthol therapy. Here, we use genetic and pharmacological approaches in mice to probe the role of TRPM8 in analgesia induced by L-menthol, the predominant analgesic menthol isomer in medicinal preparations. L-menthol effectively diminished pain behavior elicited by chemical stimuli (capsaicin, acrolein, acetic acid), noxious heat, and inflammation (complete Freund's adjuvant). Genetic deletion of TRPM8 completely abolished analgesia by L-menthol in all these models, although other analgesics (acetaminophen) remained effective. Loss of L-menthol-induced analgesia was recapitulated in mice treated with a selective TRPM8 inhibitor, AMG2850. Selective activation of TRPM8 with WS-12, a menthol derivative that we characterized as a specific TRPM8 agonist in cultured sensory neurons and in vivo, also induced TRPM8-dependent analgesia of acute and inflammatory pain. L-menthol- and WS-12-induced analgesia was blocked by naloxone, suggesting activation of endogenous opioid-dependent analgesic pathways. Our data show that TRPM8 is the principal mediator of menthol-induced analgesia of acute and inflammatory pain. In contrast to menthol, selective TRPM8 agonists may produce analgesia more effectively, with diminished side effects.
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