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Szallasi A. Resiniferatoxin: Nature's Precision Medicine to Silence TRPV1-Positive Afferents. Int J Mol Sci 2023; 24:15042. [PMID: 37894723 PMCID: PMC10606200 DOI: 10.3390/ijms242015042] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/27/2023] [Accepted: 10/07/2023] [Indexed: 10/29/2023] Open
Abstract
Resiniferatoxin (RTX) is an ultrapotent capsaicin analog with a unique spectrum of pharmacological actions. The therapeutic window of RTX is broad, allowing for the full desensitization of pain perception and neurogenic inflammation without causing unacceptable side effects. Intravesical RTX was shown to restore continence in a subset of patients with idiopathic and neurogenic detrusor overactivity. RTX can also ablate sensory neurons as a "molecular scalpel" to achieve permanent analgesia. This targeted (intrathecal or epidural) RTX therapy holds great promise in cancer pain management. Intra-articular RTX is undergoing clinical trials to treat moderate-to-severe knee pain in patients with osteoarthritis. Similar targeted approaches may be useful in the management of post-operative pain or pain associated with severe burn injuries. The current state of this field is reviewed, from preclinical studies through veterinary medicine to clinical trials.
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Affiliation(s)
- Arpad Szallasi
- Department of Pathology and Experimental Cancer Research, Semmelweis University, 1083 Budapest, Hungary
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2
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Yamaguchi T, Salavatian S, Kuwabara Y, Hellman A, Taylor BK, Howard-Quijano K, Mahajan A. Thoracic Dorsal Root Ganglion Application of Resiniferatoxin Reduces Myocardial Ischemia-Induced Ventricular Arrhythmias. Biomedicines 2023; 11:2720. [PMID: 37893094 PMCID: PMC10604235 DOI: 10.3390/biomedicines11102720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/29/2023] Open
Abstract
BACKGROUND A myocardial ischemia/reperfusion (IR) injury activates the transient receptor potential vanilloid 1 (TRPV1) dorsal root ganglion (DRG) neurons. The activation of TRPV1 DRG neurons triggers the spinal dorsal horn and the sympathetic preganglionic neurons in the spinal intermediolateral column, which results in sympathoexcitation. In this study, we hypothesize that the selective epidural administration of resiniferatoxin (RTX) to DRGs may provide cardioprotection against ventricular arrhythmias by inhibiting afferent neurotransmission during IR injury. METHODS Yorkshire pigs (n = 21) were assigned to either the sham, IR, or IR + RTX group. A laminectomy and sternotomy were performed on the anesthetized animals to expose the left T2-T4 spinal dorsal root and the heart for IR intervention, respectively. RTX (50 μg) was administered to the DRGs in the IR + RTX group. The activation recovery interval (ARI) was measured as a surrogate for the action potential duration (APD). Arrhythmia risk was investigated by assessing the dispersion of repolarization (DOR), a marker of arrhythmogenicity, and measuring the arrhythmia score and the number of non-sustained ventricular tachycardias (VTs). TRPV1 and calcitonin gene-related peptide (CGRP) expressions in DRGs and CGRP expression in the spinal cord were assessed using immunohistochemistry. RESULTS The RTX mitigated IR-induced ARI shortening (-105 ms ± 13 ms in IR vs. -65 ms ± 11 ms in IR + RTX, p = 0.028) and DOR augmentation (7093 ms2 ± 701 ms2 in IR vs. 3788 ms2 ± 1161 ms2 in IR + RTX, p = 0.020). The arrhythmia score and VT episodes during an IR were decreased by RTX (arrhythmia score: 8.01 ± 1.44 in IR vs. 3.70 ± 0.81 in IR + RTX, p = 0.037. number of VT episodes: 12.00 ± 3.29 in IR vs. 0.57 ± 0.3 in IR + RTX, p = 0.002). The CGRP expression in the DRGs and spinal cord was decreased by RTX (DRGs: 6.8% ± 1.3% in IR vs. 0.6% ± 0.2% in IR + RTX, p < 0.001. Spinal cord: 12.0% ± 2.6% in IR vs. 4.5% ± 0.8% in IR + RTX, p = 0.047). CONCLUSIONS The administration of RTX locally to thoracic DRGs reduces ventricular arrhythmia in a porcine model of IR, likely by inhibiting spinal afferent hyperactivity in the cardio-spinal sympathetic pathways.
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Affiliation(s)
- Tomoki Yamaguchi
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; (T.Y.); (S.S.); (Y.K.); (A.H.); (B.K.T.); (K.H.-Q.)
| | - Siamak Salavatian
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; (T.Y.); (S.S.); (Y.K.); (A.H.); (B.K.T.); (K.H.-Q.)
- Division of Cardiology, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
| | - Yuki Kuwabara
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; (T.Y.); (S.S.); (Y.K.); (A.H.); (B.K.T.); (K.H.-Q.)
| | - Abigail Hellman
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; (T.Y.); (S.S.); (Y.K.); (A.H.); (B.K.T.); (K.H.-Q.)
| | - Bradley K. Taylor
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; (T.Y.); (S.S.); (Y.K.); (A.H.); (B.K.T.); (K.H.-Q.)
| | - Kimberly Howard-Quijano
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; (T.Y.); (S.S.); (Y.K.); (A.H.); (B.K.T.); (K.H.-Q.)
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
| | - Aman Mahajan
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; (T.Y.); (S.S.); (Y.K.); (A.H.); (B.K.T.); (K.H.-Q.)
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
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3
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Grant PE, Caneris OA, Gonzalez RG, Iadarola MJ, Sapio MR, Mannes AJ, Borsook D. Analgesia after dorsal root ganglionic injection under CT-guidance in a patient with intractable phantom limb pain. PAIN MEDICINE (MALDEN, MASS.) 2023; 24:1122-1123. [PMID: 36975616 PMCID: PMC10472484 DOI: 10.1093/pm/pnad039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/16/2023] [Accepted: 03/20/2023] [Indexed: 03/29/2023]
Affiliation(s)
- P Ellen Grant
- Departments of Medicine and Radiology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, United States
| | - Onassis A Caneris
- Department of Interventional Spine Treatment and Pain Management, Riverhills Neuroscience, Cincinnati, OH 45212, United States
| | - Ramon G Gonzalez
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, United States
| | - Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, PHS, DHHS, Bethesda, MD 20892, United States
| | - Matthew R Sapio
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, PHS, DHHS, Bethesda, MD 20892, United States
| | - Andrew J Mannes
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, PHS, DHHS, Bethesda, MD 20892, United States
| | - David Borsook
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, United States
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Javed H, Johnson AM, Challagandla AK, Emerald BS, Shehab S. Cutaneous Injection of Resiniferatoxin Completely Alleviates and Prevents Nerve-Injury-Induced Neuropathic Pain. Cells 2022; 11:cells11244049. [PMID: 36552812 PMCID: PMC9776507 DOI: 10.3390/cells11244049] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/29/2022] [Accepted: 12/09/2022] [Indexed: 12/16/2022] Open
Abstract
Fifth lumbar (L5) nerve injury in rodent produces neuropathic manifestations in the corresponding hind paw. The aim of this study was to investigate the effect of cutaneous injection of resiniferatoxin (RTX), a TRPV1 receptor agonist, in the rat's hind paw on the neuropathic pain induced by L5 nerve injury. The results showed that intraplantar injection of RTX (0.002%, 100 µL) (1) completely reversed the development of chronic thermal and mechanical hypersensitivity; (2) completely prevented the development of nerve-injury-induced thermal and mechanical hypersensitivity when applied one week earlier; (3) caused downregulation of nociceptive pain markers, including TRPV1, IB4 and CGRP, and upregulation of VIP in the ipsilateral dorsal horn of spinal cord and dorsal root ganglion (DRG) immunohistochemically and a significant reduction in the expression of TRPV1 mRNA and protein in the ipsilateral DRG using Western blot and qRT-PCR techniques; (4) caused downregulation of PGP 9.5- and CGRP-immunoreactivity in the injected skin; (5) produced significant suppression of c-fos expression, as a neuronal activity marker, in the spinal neurons in response to a second intraplantar RTX injection two weeks later. This work identifies the ability of cutaneous injection of RTX to completely alleviate and prevent the development of different types of neuropathic pain in animals and humans.
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Zdora I, Jubran L, Allnoch L, Hansmann F, Baumgärtner W, Leitzen E. Morphological and phenotypical characteristics of porcine satellite glial cells of the dorsal root ganglia. Front Neuroanat 2022; 16:1015281. [PMID: 36337140 PMCID: PMC9626980 DOI: 10.3389/fnana.2022.1015281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/04/2022] [Indexed: 10/23/2023] Open
Abstract
Satellite glial cells (SGCs) of the dorsal root ganglia (DRG) ensure homeostasis and proportional excitability of sensory neurons and gained interest in the field of development and maintenance of neuropathic pain. Pigs represent a suitable species for translational medicine with a more similar anatomy and physiology to humans compared to rodents, and are used in research regarding treatment of neuropathic pain. Knowledge of anatomical and physiological features of porcine SGCs is prerequisite for interpreting potential alterations. However, state of knowledge is still limited. In the present study, light microscopy, ultrastructural analysis and immunofluorescence staining was performed. SGCs tightly surround DRG neurons with little vascularized connective tissue between SGC-neuron units, containing, among others, axons and Schwann cells. DRG were mainly composed of large sized neurons (∼59%), accompanied by fewer medium sized (∼36%) and small sized sensory neurons (∼6%). An increase of neuronal body size was concomitant with an increased number of surrounding SGCs. The majority of porcine SGCs expressed glutamine synthetase and inwardly rectifying potassium channel Kir 4.1, known as SGC-specific markers in other species. Similar to canine SGCs, marked numbers of porcine SGCs were immunopositive for glial fibrillary acidic protein, 2',3'-cyclic-nucleotide 3'-phosphodiesterase and the transcription factor Sox2. Low to moderate numbers of SGCs showed aquaporin 4-immunoreactivity (AQP4) as described for murine SGCs. AQP4-immunoreactivity was primarily found in SGCs ensheathing small and medium sized neuronal somata. Low numbers of SGCs were immunopositive for ionized calcium-binding adapter molecule 1, indicating a potential immune cell character. No immunoreactivity for common leukocyte antigen CD45 nor neural/glial antigen 2 was detected. The present study provides essential insights into the characteristic features of non-activated porcine SGCs, contributing to a better understanding of this cell population and its functional aspects. This will help to interpret possible changes that might occur under activating conditions such as pain.
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Affiliation(s)
- Isabel Zdora
- Department of Pathology, University of Veterinary Medicine, Hanover, Germany
- Center of Systems Neuroscience, Hanover Graduate School for Neurosciences, Infection Medicine, and Veterinary Sciences (HGNI), Hanover, Germany
| | - Lorna Jubran
- Department of Pathology, University of Veterinary Medicine, Hanover, Germany
- Center of Systems Neuroscience, Hanover Graduate School for Neurosciences, Infection Medicine, and Veterinary Sciences (HGNI), Hanover, Germany
| | - Lisa Allnoch
- Department of Pathology, University of Veterinary Medicine, Hanover, Germany
| | - Florian Hansmann
- Department of Pathology, University of Veterinary Medicine, Hanover, Germany
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine, Hanover, Germany
- Center of Systems Neuroscience, Hanover Graduate School for Neurosciences, Infection Medicine, and Veterinary Sciences (HGNI), Hanover, Germany
| | - Eva Leitzen
- Department of Pathology, University of Veterinary Medicine, Hanover, Germany
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Yin S, Gao P, Yu L, Zhu L, Yu W, Chen Y, Yang L. Engineering 2D Silicene-Based Mesoporous Nanomedicine for In Vivo Near-Infrared-Triggered Analgesia. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202735. [PMID: 35750652 PMCID: PMC9443434 DOI: 10.1002/advs.202202735] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Indexed: 06/15/2023]
Abstract
The utilization of local anesthetics for postoperative analgesia represents an effective approach, but generally suffers from short half-lives and brachychronic local neurotoxicity. A desirable anesthetic with controllable and sustainable drug-releasing performance for adequate analgesia effect is highly required. In this work, the core/shell-structured two-dimenional (2D) silicene nanosheets coated with mesoporous silica layer (abbreviated as Silicene@MSNs) have been rationally constructed as localized drug-delivery system in sciatic nerve block to achieve on-demand release of loaded ropivacaine (RP) in mesoporous silica layer for local analgesia. Based on the specific photothermal performance of 2D silicene core, this local anesthesia system can be triggered by near-infrared laser to release the loaded RP, resulting in on-demand and long-lasting regional anesthesia. The analgesia effect is assessed by pain behavior tests, which demonstrates that the RP-loaded Silicene@MSNs core/shell nanosystem behaves almost five times longer analgesia effect than free RP. Furthermore, the activation of pain-related neurons in nerve conduction pathways is tested to explore the underlying analgesia mechanism, revealing that the designed nanosystem can improve the pain threshold, reduce the activation of neurons in dorsal root ganglion and excitability in spinal substantia gelatinosa neurons. This designed anesthetic nanomedicine provides a facile but effective methodology for long-lasting regional anesthesia.
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Affiliation(s)
- Suqing Yin
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, P. R. China
| | - Po Gao
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, P. R. China
| | - Luodan Yu
- Materdicine Lab, School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China
| | - Ling Zhu
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, P. R. China
| | - Weifeng Yu
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, P. R. China
| | - Yu Chen
- Materdicine Lab, School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China
| | - Liqun Yang
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, P. R. China
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Characterization of Patients With and Without Painful Peripheral Neuropathy After Receiving Neurotoxic Chemotherapy: Traditional Quantitative Sensory Testing vs C-Fiber and Aδ-Fiber Selective Diode Laser Stimulation. THE JOURNAL OF PAIN 2022; 23:796-809. [PMID: 34896646 PMCID: PMC9086082 DOI: 10.1016/j.jpain.2021.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 11/09/2021] [Accepted: 11/12/2021] [Indexed: 11/21/2022]
Abstract
Painful chemotherapy induced peripheral neuropathy (CIPN) is a common complication of chemotherapy with drugs such as taxanes and platinum compounds. Currently, no methods are available for early detection of sensory changes that are associated with painful CIPN, nor are there biomarkers that are specific to painful CIPN. This study aimed to compare Diode Laser fiber type-selective stimulator (DLss), a method to selectively stimulate cutaneous C and Aδ fibers, to traditional quantitative sensory testing (QST) in determining psychophysical differences between patients with painful CIPN and a control group. Sensory testing was performed on the dorsal mid-foot of 20 patients with painful neuropathy after taxane- or platinum-based chemotherapy, and 20 patients who received similar neurotoxic chemotherapy, without painful CIPN. In a multivariable analysis, C-fiber to Aδ fiber detection threshold ratio, measured by DLss, was significantly different between the groups (P <.05). While QST parameters such as warmth detection threshold were different between the groups in univariate analyses, these findings were likely attributable to group differences in patient age and cumulative chemotherapy dose. PERSPECTIVE: In this study, fiber-specific DLss test showed potential in identifying sensory changes that are specific for painful neuropathy, encouraging future testing of this approach as a biomarker for early detection of painful CIPN. TRIAL REGISTRATION: The study was approved by the Washington University Institutional Review Board (#201807162) and registered at ClinicalTrials.gov (NCT03687970).
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8
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Nemenov MI, Singleton JR, Premkumar LS. Role of Mechanoinsensitive Nociceptors in Painful Diabetic Peripheral Neuropathy. Curr Diabetes Rev 2022; 18:e081221198649. [PMID: 34879806 DOI: 10.2174/1573399818666211208101555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 03/08/2021] [Accepted: 07/09/2021] [Indexed: 11/22/2022]
Abstract
The cutaneous mechanisms that trigger spontaneous neuropathic pain in diabetic peripheral neuropathy (PDPN) are far from clear. Two types of nociceptors are found within the epidermal and dermal skin layers. Small-diameter lightly myelinated Aδ and unmyelinated C cutaneous mechano and heat-sensitive (AMH and CMH) and C mechanoinsensitive (CMi) nociceptors transmit pain from the periphery to central nervous system. AMH and CMH fibers are mainly located in the epidermis, and CMi fibers are distributed in the dermis. In DPN, dying back intra-epidermal AMH and CMH fibers leads to reduced pain sensitivity, and the patients exhibit significantly increased pain thresholds to acute pain when tested using traditional methods. The role of CMi fibers in painful neuropathies has not been fully explored. Microneurography has been the only tool to access CMi fibers and differentiate AMH, CMH, and CMi fiber types. Due to the complexity, its use is impractical in clinical settings. In contrast, a newly developed diode laser fiber selective stimulation (DLss) technique allows to safely and selectively stimulate Aδ and C fibers in the superficial and deep skin layers. DLss data demonstrate that patients with painful DPN have increased Aδ fiber pain thresholds, while C-fiber thresholds are intact because, in these patients, CMi fibers are abnormally spontaneously active. It is also possible to determine the involvement of CMi fibers by measuring the area of DLss-induced neurogenic axon reflex flare. The differences in AMH, CMH, and CMi fibers identify patients with painful and painless neuropathy. In this review, we will discuss the role of CMi fibers in PDPN.
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Affiliation(s)
- Mikhail I Nemenov
- Department of Anesthesia, Stanford University, Palo Alto, CA, USA
- Lasmed LLC, Mountain View, CA, USA
| | | | - Louis S Premkumar
- Department of Pharmacology, SIU School of Medicine, Springfield, Illinois, USA and Ion Channel Pharmacology LLC, Springfield, IL, USA
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Mannozzi J, Al-Hassan MH, Lessanework B, Alvarez A, Senador D, O'Leary DS. Chronic ablation of TRPV1-sensitive skeletal muscle afferents attenuates the muscle metaboreflex. Am J Physiol Regul Integr Comp Physiol 2021; 321:R385-R395. [PMID: 34259041 DOI: 10.1152/ajpregu.00129.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Exercise intolerance is a hallmark symptom of cardiovascular disease and likely occurs via enhanced activation of muscle metaboreflex-induced vasoconstriction of the heart and active skeletal muscle which, thereby limits cardiac output and peripheral blood flow. Muscle metaboreflex vasoconstrictor responses occur via activation of metabolite-sensitive afferent fibers located in ischemic active skeletal muscle, some of which express transient receptor potential vanilloid 1 (TRPV1) cation channels. Local cardiac and intrathecal administration of an ultrapotent noncompetitive, dominant negative agonist resiniferatoxin (RTX) can ablate these TRPV1-sensitive afferents. This technique has been used to attenuate cardiac sympathetic afferents and nociceptive pain. We investigated whether intrathecal administration (L4-L6) of RTX (2 µg/kg) could chronically attenuate subsequent muscle metaboreflex responses elicited by reductions in hindlimb blood flow during mild exercise (3.2 km/h) in chronically instrumented conscious canines. RTX significantly attenuated metaboreflex-induced increases in mean arterial pressure (27 ± 5.0 mmHg vs. 6 ± 8.2 mmHg), cardiac output (1.40 ± 0.2 L/min vs. 0.28 ± 0.1 L/min), and stroke work (2.27 ± 0.2 L·mmHg vs. 1.01 ± 0.2 L·mmHg). Effects were maintained until 78 ± 14 days post-RTX at which point the efficacy of RTX injection was tested by intra-arterial administration of capsaicin (20 µg/kg). A significant reduction in the mean arterial pressure response (+45.7 ± 6.5 mmHg pre-RTX vs. +19.7 ± 3.1 mmHg post-RTX) was observed. We conclude that intrathecal administration of RTX can chronically attenuate the muscle metaboreflex and could potentially alleviate enhanced sympatho-activation observed in cardiovascular disease states.
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Affiliation(s)
- Joseph Mannozzi
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | | | - Beruk Lessanework
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Alberto Alvarez
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Danielle Senador
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Donal S O'Leary
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
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Iadarola MJ, Brown DC, Nahama A, Sapio MR, Mannes AJ. Pain Treatment in the Companion Canine Model to Validate Rodent Results and Incentivize the Transition to Human Clinical Trials. Front Pharmacol 2021; 12:705743. [PMID: 34421597 PMCID: PMC8375595 DOI: 10.3389/fphar.2021.705743] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/14/2021] [Indexed: 12/14/2022] Open
Abstract
One of the biggest challenges for analgesic drug development is how to decide if a potential analgesic candidate will work in humans. What preclinical data are the most convincing, incentivizing and most predictive of success? Such a predicament is not unique to analgesics, and the pain field has certain advantages over drug development efforts in areas like neuropsychiatry where the etiological origins are either unknown or difficult to ascertain. For pain, the origin of the problem frequently is known, and the causative peripheral tissue insult might be observable. The main conundrum centers around evaluation of translational cell- and rodent-based results. While cell and rodent models are undeniably important first steps for screening, probing mechanism of action, and understanding factors of adsorption, distribution metabolism and excretion, two questions arise from such studies. First, are they reliable indicators of analgesic performance of a candidate drug in human acute and chronic pain? Second, what additional model systems might be capable of increasing translational confidence? We address this second question by assessing, primarily, the companion canine model, which can provide particularly strong predictive information for candidate analgesic agents in humans. This statement is mainly derived from our studies with resiniferatoxin (RTX) a potent TRPV1 agonist but also from protein therapeutics using a conjugate of Substance P and saporin. Our experience, to date, is that rodent models might be very well suited for acute pain translation, but companion canine models, and other large animal studies, can augment initial discovery research using rodent models for neuropathic or chronic pain. The larger animal models also provide strong translational predictive capacity for analgesic performance in humans, better predict dosing parameters for human trials and provide insight into behavior changes (bladder, bowel, mood, etc.) that are not readily assessed in laboratory animals. They are, however, not without problems that can be encountered with any experimental drug treatment or clinical trial. It also is important to recognize that pain treatment is a major veterinary concern and is an intrinsically worthwhile endeavor for animals as well as humans.
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Affiliation(s)
- Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, NIH, Bethesda, MD, United States
| | | | | | - Matthew R Sapio
- Department of Perioperative Medicine, Clinical Center, NIH, Bethesda, MD, United States
| | - Andrew J Mannes
- Department of Perioperative Medicine, Clinical Center, NIH, Bethesda, MD, United States
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11
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Iadarola MJ. Unilateral Periganglionic Resiniferatoxin for Personalized Pain Treatment. PAIN MEDICINE 2021; 22:767-768. [PMID: 33106868 DOI: 10.1093/pm/pnaa393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, Maryland, USA
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12
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Beutler AS, Unger MD, Banck MS, Maus TP. Response to "Unilateral Periganglionic Resiniferatoxin (RTX) for Personalized Pain Treatment". PAIN MEDICINE (MALDEN, MASS.) 2021; 22:768-769. [PMID: 33200173 PMCID: PMC7971457 DOI: 10.1093/pm/pnaa394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
| | - Mark D Unger
- Interventional AnalgesiX Inc., Durham, North Carolina, USA
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Fight fire with fire: Neurobiology of capsaicin-induced analgesia for chronic pain. Pharmacol Ther 2020; 220:107743. [PMID: 33181192 DOI: 10.1016/j.pharmthera.2020.107743] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/04/2020] [Indexed: 12/12/2022]
Abstract
Capsaicin, the pungent ingredient in chili peppers, produces intense burning pain in humans. Capsaicin selectively activates the transient receptor potential vanilloid 1 (TRPV1), which is enriched in nociceptive primary afferents, and underpins the mechanism for capsaicin-induced burning pain. Paradoxically, capsaicin has long been used as an analgesic. The development of topical patches and injectable formulations containing capsaicin has led to application in clinical settings to treat chronic pain conditions, such as neuropathic pain and the potential to treat osteoarthritis. More detailed determination of the neurobiological mechanisms of capsaicin-induced analgesia should provide the logical rationale for capsaicin therapy and help to overcome the treatment's limitations, which include individual differences in treatment outcome and procedural discomfort. Low concentrations of capsaicin induce short-term defunctionalization of nociceptor terminals. This phenomenon is reversible within hours and, hence, likely does not account for the clinical benefit. By contrast, high concentrations of capsaicin lead to long-term defunctionalization mediated by the ablation of TRPV1-expressing afferent terminals, resulting in long-lasting analgesia persisting for several months. Recent studies have shown that capsaicin-induced Ca2+/calpain-mediated ablation of axonal terminals is necessary to produce long-lasting analgesia in a mouse model of neuropathic pain. In combination with calpain, axonal mitochondrial dysfunction and microtubule disorganization may also contribute to the longer-term effects of capsaicin. The analgesic effects subside over time in association with the regeneration of the ablated afferent terminals. Further determination of the neurobiological mechanisms of capsaicin-induced analgesia should lead to more efficacious non-opioidergic analgesic options with fewer adverse side effects.
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Abstract
The transient receptor potential vanilloid-1 (TRPV1) is a non-specific cation channel known for its sensitivity to pungent vanilloid compound (i.e. capsaicin) and noxious stimuli, including heat, low pH or inflammatory mediators. TRPV1 is found in the somatosensory system, particularly primary afferent neurons that respond to damaging or potentially damaging stimuli (nociceptors). Stimulation of TRPV1 evokes a burning sensation, reflecting a central role of the channel in pain. Pharmacological and genetic studies have validated TRPV1 as a therapeutic target in several preclinical models of chronic pain, including cancer, neuropathic, postoperative and musculoskeletal pain. While antagonists of TRPV1 were found to be a valuable addition to the pain therapeutic toolbox, their clinical use has been limited by detrimental side effects, such as hyperthermia. In contrast, capsaicin induces a prolonged defunctionalisation of nociceptors and thus opened the door to the development of a new class of therapeutics with long-lasting pain-relieving effects. Here we review the list of TRPV1 agonists undergoing clinical trials for chronic pain management, and discuss new indications, formulations or combination therapies being explored for capsaicin. While the analgesic pharmacopeia for chronic pain patients is ancient and poorly effective, modern TRPV1-targeted drugs could rapidly become available as the next generation of analgesics for a broad spectrum of pain conditions.
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Affiliation(s)
- Mircea Iftinca
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta, T2N 4N1, Canada
| | - Manon Defaye
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta, T2N 4N1, Canada
| | - Christophe Altier
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta, T2N 4N1, Canada.
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Mohandass A, Surenkhuu B, Covington K, Baskaran P, Lehmann T, Thyagarajan B. Kainic Acid Activates TRPV1 via a Phospholipase C/PIP2-Dependent Mechanism in Vitro. ACS Chem Neurosci 2020; 11:2999-3007. [PMID: 32833423 PMCID: PMC7747480 DOI: 10.1021/acschemneuro.0c00297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Kainic acid (KA) is an excitotoxic glutamate analogue produced by a marine seaweed. It elicits neuronal excitotoxicity leading to epilepsy in rodents. Activation of transient receptor potential vanilloid subfamily 1 (TRPV1), a nonselective cation channel protein, by capsaicin, prevents KA-induced seizures in a mouse model of temporal lobe epilepsy. However, the precise mechanism behind this protective effect of capsaicin remains unclear. In order to analyze the direct effect of KA on TRPV1, we evaluated the ability of KA to activate TRPV1 and analyzed its binding to TRPV1 using a molecular modeling approach. In vitro, KA activates a Ca2+ influx into TRPV1 expressing HEK293 cells but not in contsrol HEK293 cells. Pretreatment with either capsaicin (1 M) or capsazepine (10 M; TRPV1 antagonist) prevents the effect of KA. Pharmacological inhibition of phospholipase C (PLC) by U73122 or overexpression of phosphatidylinositol 5 phosphatase (Synaptojanin 1; Synj-1) counters the effect of KA. Further, KA treatment causes actin reorganization in HEKTRPV1 cells and PLC inhibition by U73122 prevents this. Molecular modeling data revealed that KA binds to TRPV1 and prebinding with capsaicin prevents the binding of KA to TRPV1. Consistently, the lack of effect of KA in activating chicken TRPV1, which is insensitive to capsaicin, suggests that there is a significant overlap between the sites of KA and capsaicin activation of TRPV1. However, PLC inhibition did not suppress TRPV1 activation by capsaicin. Collectively, our data suggest that KA binds to and activates TRPV1 and causes actin reorganization via PLC-dependent mechanism in vitro. We propose that KA mediates Ca2+ induced toxicity possibly by activating TRPV1. Therefore, inhibiting TRPV1 will be a beneficial strategy in abating Ca2+-induced neurotoxicity.
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Toschi A, Tugnoli B, Rossi B, Piva A, Grilli E. Thymol modulates the endocannabinoid system and gut chemosensing of weaning pigs. BMC Vet Res 2020; 16:289. [PMID: 32787931 PMCID: PMC7425016 DOI: 10.1186/s12917-020-02516-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 08/06/2020] [Indexed: 12/13/2022] Open
Abstract
Background The recent identification of the endocannabinoid system in the gastrointestinal tract suggests a role in controlling intestinal inflammation. In addition, the gut chemosensing system has therapeutic applications in the treatment of gastrointestinal diseases and inflammation due to the presence of a large variety of receptors. The purposes of this study were to investigate the presence of markers of the endocannabinoid system and the chemosensing system in the pig gut and, second, to determine if thymol modulates these markers. One hundred sixty 28-day-old piglets were allocated into one of 5 treatment groups (n = 32 per treatment): T1 (control), T2 (25.5 mg thymol/kg feed), T3 (51 mg thymol/kg feed), T4 (153 mg thymol/kg feed), and T5 (510 mg thymol/kg feed). After 14 days of treatment, piglets were sacrificed (n = 8), and then duodenal and ileal mucosal scrapings were collected. Gene expression of cannabinoid receptors (CB1 and CB2), transient receptor potential vanilloid 1 (TRPV1), the olfactory receptor OR1G1, diacylglycerol lipases (DGL-α and DGL-β), fatty acid amine hydrolase (FAAH), and cytokines was measured, and ELISAs of pro-inflammatory cytokines levels were performed. Results mRNAs encoding all markers tested were detected. In the duodenum and ileum, the CB1, CB2, TRPV1, and OR1G1 mRNAs were expressed at higher levels in the T4 and T5 groups compared to the control group. The level of the FAAH mRNA was increased in the ileum of the T4 group compared to the control. Regarding the immune response, the level of the tumor necrosis factor (TNF-α) mRNA was significantly increased in the duodenum of the T5 group, but this increase was not consistent with the protein level. Conclusions These results indicate the presence of endocannabinoid system and gut chemosensing markers in the piglet gut mucosa. Moreover, thymol modulated the expression of the CB1, CB2, TRPV1, and OR1G1 mRNAs in the duodenum and ileum. It also modulated the mRNA levels of enzymes involved in the biosynthesis and degradation of endocannabinoid molecules. Based on these findings, the effects of thymol on promoting gut health are potentially mediated by the activation of these receptors.
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Affiliation(s)
- Andrea Toschi
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia, BO, Italy
| | | | - Barbara Rossi
- Vetagro SpA, via Porro, 2, 42124, Reggio Emilia, Italy
| | - Andrea Piva
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia, BO, Italy.,Vetagro SpA, via Porro, 2, 42124, Reggio Emilia, Italy
| | - Ester Grilli
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia, BO, Italy. .,Vetagro, Inc., 116 W. Jackson Blvd, Chicago, IL, 60604, USA.
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The capsaicin receptor TRPV1 is the first line defense protecting from acute non damaging heat: a translational approach. J Transl Med 2020; 18:28. [PMID: 31952468 PMCID: PMC6966804 DOI: 10.1186/s12967-019-02200-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/26/2019] [Indexed: 02/07/2023] Open
Abstract
Background Pain is the vital sense preventing tissue damage by harmful noxious stimuli. The capsaicin receptor TRPV1 is activated by noxious temperatures, however, acute heat pain is only marginally affected in mice after TRPV1 knockout but completely eliminated in mice lacking TRPV1 positive fibers. Exploring contribution of candidate signal transduction mechanisms to heat pain in humans needs translational models. Methods We used focused, non-damaging, short near-infrared laser heat stimuli (wavelength 1470/1475 nm) to study the involvement of TRPV1-expressing nerve fibers in the encoding of heat pain intensity. Human psychophysics (both sexes) were compared to calcium transients in native rat DRG neurons and heterologously expressing HEK293 cells. Results Heating of dermal and epidermal nerve fibers in humans with laser stimuli of ≥ 2.5 mJ (≥ 25 ms, 100 mW) induced pain that increased linearly as a function of stimulus intensity in double logarithmic space across two orders of magnitude and was completely abolished by desensitization using topical capsaicin. In DRG neurons and TRPV1-expressing HEK cells, heat sensitivity was restricted to capsaicin sensitive cells. Strength duration curves (2–10 ms range) and thresholds (DRGs 0.56 mJ, HEK cells 0.52 mJ) were nearly identical. Tachyphylaxis upon repetitive stimulation occurred in HEK cells (54%), DRGs (59%), and humans (25%). Conclusion TRPV1-expressing nociceptors encode transient non-damaging heat pain in humans, thermal gating of TRPV1 is similar in HEK cells and DRG neurons, and TRPV1 tachyphylaxis is an important modulator of heat pain sensitivity. These findings suggest that TRPV1 expressed in dermal and epidermal populations of nociceptors serves as first line defense against heat injury.
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Resiniferatoxin reduces ventricular arrhythmias in heart failure via selectively blunting cardiac sympathetic afferent projection into spinal cord in rats. Eur J Pharmacol 2020; 867:172836. [DOI: 10.1016/j.ejphar.2019.172836] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 12/13/2022]
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Transcriptional Changes in Dorsal Spinal Cord Persist after Surgical Incision Despite Preemptive Analgesia with Peripheral Resiniferatoxin. Anesthesiology 2019; 128:620-635. [PMID: 29271803 DOI: 10.1097/aln.0000000000002006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Peripheral nociceptors expressing the ion channel transient receptor potential cation channel, subfamily V, member 1, play an important role in mediating postoperative pain. Signaling from these nociceptors in the peri- and postoperative period can lead to plastic changes in the spinal cord and, when controlled, can yield analgesia. The transcriptomic changes in the dorsal spinal cord after surgery, and potential coupling to transient receptor potential cation channel, subfamily V, member 1-positive nociceptor signaling, remain poorly studied. METHODS Resiniferatoxin was injected subcutaneously into rat hind paw several minutes before surgical incision to inactivate transient receptor potential cation channel, subfamily V, member 1-positive nerve terminals. The effects of resiniferatoxin on postincisional measures of pain were assessed through postoperative day 10 (n = 51). Transcriptomic changes in the dorsal spinal cord, with and without peripheral transient receptor potential cation channel, subfamily V, member 1-positive nerve terminal inactivation, were assessed by RNA sequencing (n = 22). RESULTS Peripherally administered resiniferatoxin increased thermal withdrawal latency by at least twofold through postoperative day 4, increased mechanical withdrawal threshold by at least sevenfold through postoperative day 2, and decreased guarding score by 90% relative to vehicle control (P < 0.05). Surgical incision induced 70 genes in the dorsal horn, and these changes were specific to the ipsilateral dorsal horn. Gene induction with surgical incision persisted despite robust analgesia from resiniferatoxin pretreatment. Many of the genes induced were related to microglial activation, such as Cd11b and Iba1. CONCLUSIONS A single subcutaneous injection of resiniferatoxin before incision attenuated both evoked and nonevoked measures of postoperative pain. Surgical incision induced transcriptomic changes in the dorsal horn that persisted despite analgesia with resiniferatoxin, suggesting that postsurgical pain signals can be blocked without preventing transcription changes in the dorsal horn.
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20
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Maatuf Y, Geron M, Priel A. The Role of Toxins in the Pursuit for Novel Analgesics. Toxins (Basel) 2019; 11:toxins11020131. [PMID: 30813430 PMCID: PMC6409898 DOI: 10.3390/toxins11020131] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/17/2019] [Accepted: 02/20/2019] [Indexed: 12/19/2022] Open
Abstract
Chronic pain is a major medical issue which reduces the quality of life of millions and inflicts a significant burden on health authorities worldwide. Currently, management of chronic pain includes first-line pharmacological therapies that are inadequately effective, as in just a portion of patients pain relief is obtained. Furthermore, most analgesics in use produce severe or intolerable adverse effects that impose dose restrictions and reduce compliance. As the majority of analgesic agents act on the central nervous system (CNS), it is possible that blocking pain at its source by targeting nociceptors would prove more efficient with minimal CNS-related side effects. The development of such analgesics requires the identification of appropriate molecular targets and thorough understanding of their structural and functional features. To this end, plant and animal toxins can be employed as they affect ion channels with high potency and selectivity. Moreover, elucidation of the toxin-bound ion channel structure could generate pharmacophores for rational drug design while favorable safety and analgesic profiles could highlight toxins as leads or even as valuable therapeutic compounds themselves. Here, we discuss the use of plant and animal toxins in the characterization of peripherally expressed ion channels which are implicated in pain.
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Affiliation(s)
- Yossi Maatuf
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
| | - Matan Geron
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
| | - Avi Priel
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
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21
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Long-term pain relief in canine osteoarthritis by a single intra-articular injection of resiniferatoxin, a potent TRPV1 agonist. Pain 2019; 159:2105-2114. [PMID: 30015705 DOI: 10.1097/j.pain.0000000000001314] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The translational potential of analgesic approaches emerging from basic research can be augmented by client-owned dog trials. We report on a peripheral interventional approach that uses intra-articular injection of the ultrapotent TRPV1 agonist resiniferatoxin (RTX) to produce a selective long-term chemoinactivation of nociceptive primary afferent nerve endings for pain control in naturally occurring canine osteoarthritis. A single injection of 10 µg of RTX, produced suppression of pain, improvement in gait, weight bearing, and improvement in the dog's activities of daily living lasting 4 months or longer. Two to 3 years after the injection, there are no alterations to suggest that removal of inflammatory pain caused accelerated joint degeneration (Charcot joint) in any of the dogs. To amplify the effective use of canine subjects in translational analgesia research, we report a high-quality canine dorsal root ganglion transcriptome. Some targets for analgesia are highly conserved both in protein sequence and level of expression within a target tissue while others diverge substantially from the human. This knowledge is especially important for development of analgesics aimed at peripheral molecular targets and provides a template for informed translational research. The peripheral site of action, long duration of analgesia, apparent safety, and retention of coordination, all resulting from a single dose suggest that intra-articular RTX may be an effective intervention for osteoarthritis pain with few or no side effects and lead to an improved quality of life.
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22
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Isensee J, Hucho T. High-Content Imaging of Immunofluorescently Labeled TRPV1-Positive Sensory Neurons. Methods Mol Biol 2019; 1987:111-124. [PMID: 31028677 DOI: 10.1007/978-1-4939-9446-5_8] [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] [Indexed: 06/09/2023]
Abstract
Studying TRP channel expressing nociceptors requires the identification of the respective subpopulations as well as the quantification of dynamic cellular events. However, the heterogeneity of sensory neurons and associated nonneuronal cells demands the analysis of large numbers of cells to reflect the distribution of entire populations. Here we report a detailed workflow how to apply high-content screening (HCS) microscopy to signaling events in TRPV1-positive neurons as well as an approach to use the selective elimination of TRPV1 positive cells from dissociated rat sensory ganglia as base for transcriptomic analysis of TRPV1-positive cells and/or as control for TRPV1 antibody specificity.
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Affiliation(s)
- Jörg Isensee
- Experimental Anesthesiology and Pain Research, Department of Anesthesiology and Intensive Care Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Tim Hucho
- Experimental Anesthesiology and Pain Research, Department of Anesthesiology and Intensive Care Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany.
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23
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Maus TP, Felmlee JP, Unger MD, Beutler AS. MRI guidance technology development in a large animal model for hyperlocal analgesics delivery to the epidural space and dorsal root ganglion. J Neurosci Methods 2018; 312:182-186. [PMID: 30513305 DOI: 10.1016/j.jneumeth.2018.11.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 11/29/2018] [Accepted: 11/30/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Development of new analgesic drugs or gene therapy vectors for spinal delivery will be facilitated by "hyperlocal" targeting of small therapeutic injectate volumes if spine imaging technology can be used that is ready for future clinical translation. NEW METHOD This study provides methods for MRI-guided drug delivery to the periganglionic epidural space and the dorsal root ganglion (DRG) in the Yucatan swine. RESULTS Phantom studies showed artifact-corrected needle localization with frequency encoding parallel to the needle shaft, while maximizing bandwidth (125 KHz) minimized needle artifact. A custom constructed 8-12 element surface coil (phased array) wrapped over the spine in conjunction with lateral recumbent positioning achieved diagnostic quality signal to noise ratio at the depth of the DRG and afforded transforaminal access via anterolateral or posterolateral vectors, as well as interlaminar access. Swine epidural anatomy was homologous with human anatomy. Injectate containing 2% gadolinium allowed imaging of injectate volumes in increments as small as 10 microliters and discrimination of epidural flow from intraparenchymal injectate delivery into a DRG. All technical and technological elements of the procedure appear clinically translatable. COMPARISON WITH EXISTING METHODS Computed tomographic or fluoroscopic guidance cannot directly visualize drug delivery into the DRG due to contrast medium toxicity, nor reliably identify epidural injection volumes of < 50 microliters. CONCLUSIONS MRI-guided hyperlocal delivery in swine provides a translatable and faithful model of future human spinal novel drug- or gene therapy vector delivery.
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Affiliation(s)
- Timothy P Maus
- Department of Radiology, Mayo Graduate School, Mayo Clinic, Rochester, MN, 55902, USA.
| | - Joel P Felmlee
- Department of Radiology, Mayo Graduate School, Mayo Clinic, Rochester, MN, 55902, USA
| | - Mark D Unger
- Department of Anesthesiology, Mayo Graduate School, Mayo Clinic, Rochester, MN, 55902, USA; Department of Oncology, Mayo Clinic, Mayo Graduate School, Mayo Clinic, Rochester, MN, 55902, USA; Translational Science Track, Mayo Graduate School, Mayo Clinic, Rochester, MN, 55902, USA
| | - Andreas S Beutler
- Department of Anesthesiology, Mayo Graduate School, Mayo Clinic, Rochester, MN, 55902, USA; Department of Oncology, Mayo Clinic, Mayo Graduate School, Mayo Clinic, Rochester, MN, 55902, USA; Translational Science Track, Mayo Graduate School, Mayo Clinic, Rochester, MN, 55902, USA.
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24
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Iadarola MJ, Sapio MR, Wang X, Carrero H, Virata-Theimer ML, Sarnovsky R, Mannes AJ, FitzGerald DJ. Analgesia by Deletion of Spinal Neurokinin 1 Receptor Expressing Neurons Using a Bioengineered Substance P-Pseudomonas Exotoxin Conjugate. Mol Pain 2018; 13:1744806917727657. [PMID: 28814145 PMCID: PMC5574484 DOI: 10.1177/1744806917727657] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cell deletion approaches to pain directed at either the primary nociceptive afferents or
second-order neurons are highly effective analgesic manipulations. Second-order spinal
neurons expressing the neurokinin 1 (NK1) receptor are required for the perception of many
types of pain. To delete NK1+ neurons for the purpose of pain control, we generated a
toxin–peptide conjugate using DTNB-derivatized (Cys0) substance P (SP) and a
N-terminally truncated Pseudomonas exotoxin (PE35) that retains the endosome-release and
ADP-ribosylation enzymatic domains but with only one free sulfhydryl side chain for
conjugation. This allowed generation of a one-to-one product linked by a disulfide bond
(SP-PE35). In vitro, Chinese hamster ovary cells stably transfected with the NK1 receptor
exhibited specific cytotoxicity when exposed to SP-PE35
(IC50 = 5 × 10−11 M), whereas the conjugate was nontoxic to NK2
and NK3 receptor-bearing cell lines. In vivo studies showed that, after infusion into the
spinal subarachnoid space, the toxin was extremely effective in deleting NK1
receptor-expressing cells from the dorsal horn of the spinal cord. The specific cell
deletion robustly attenuated thermal and mechanical pain sensations and inflammatory
hyperalgesia but did not affect motoric capabilities. NK1 receptor cell deletion and
antinociception occurred without obvious lesion of non–receptor-expressing cells or
apparent reorganization of primary afferent innervation. These data demonstrate the
extraordinary selectivity and broad-spectrum antinociceptive efficacy of this
ligand-directed protein therapeutic acting via receptor-mediated endocytosis. The loss of
multiple pain modalities including heat and mechanical pinch, transduced by different
populations of primary afferents, shows that spinal NK1 receptor-expressing neurons are
critical points of convergence in the nociceptive transmission circuit. We further suggest
that therapeutic end points can be effectively and safely achieved when SP-PE35 is locally
infused, thereby producing a regionally defined analgesia.
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Affiliation(s)
- Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892
| | | | - Xunde Wang
- Biotherapy Section, Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Hector Carrero
- Pain and Neurosensory Mechanisms Branch, National Institutes of Dental and Craniofacial
| | - Maria Luisa Virata-Theimer
- Biotherapy Section, Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Robert Sarnovsky
- Biotherapy Section, Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Andrew J Mannes
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892
| | - David J FitzGerald
- Biotherapy Section, Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
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25
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Salas MM, Clifford JL, Hayden JR, Iadarola MJ, Averitt DL. Local Resiniferatoxin Induces Long-Lasting Analgesia in a Rat Model of Full Thickness Thermal Injury. PAIN MEDICINE 2018; 18:2453-2465. [PMID: 27794548 DOI: 10.1093/pm/pnw260] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Objective Opioid-based analgesics are a major component of the lengthy pain management of burn patients, including military service members, but are problematic due to central nervous system-mediated side effects. Peripheral analgesia via targeted ablation of nociceptive nerve endings that express the transient receptor potential vanilloid channel 1 (TRPV1) may provide an improved approach. We hypothesized that local injection of the TRPV1 agonist resiniferatoxin (RTX) would produce long-lasting analgesia in a rat model of pain associated with burn injury. Methods Baseline sensitivities to thermal and mechanical stimuli were measured in male and female Sprague-Dawley rats. Under anesthesia, a 100 °C metal probe was placed on the right hind paw for 30 seconds, and sensitivity was reassessed 72 hours following injury. Rats received RTX (0.25 μg/100 μL; ipl) into the injured hind paw, and sensitivity was reassessed across three weeks. Tissues were collected from a separate group of rats at 24 hours and/or one week post-RTX for pathological analyses of the injured hind paw, dorsal spinal cord c-Fos, and primary afferent neuropeptide immunoreactivity. Results Local RTX reversed burn pain behaviors within 24 hours, which lasted through recovery at three weeks. At one week following RTX, decreased c-Fos and primary afferent neuropeptide immunoreactivities were observed in the dorsal horn, while plantar burn pathology was unaltered. Conclusions These results indicate that local RTX induces long-lasting analgesia in a rat model of pain associated with burn. While opioids are undesirable in trauma patients due to side effects, RTX may provide valuable long-term, nonopioid analgesia for burn patients.
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Affiliation(s)
- Margaux M Salas
- Pain Management Research Area, United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - John L Clifford
- Pain Management Research Area, United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Jessica R Hayden
- Pain Management Research Area, United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Dayna L Averitt
- Department of Biology, Texas Woman's University, Denton, Texas, USA
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Mohammadi M, Oehler B, Kloka J, Martin C, Brack A, Blum R, Rittner HL. Antinociception by the anti-oxidized phospholipid antibody E06. Br J Pharmacol 2018; 175:2940-2955. [PMID: 29679953 DOI: 10.1111/bph.14340] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 03/08/2018] [Accepted: 04/05/2018] [Indexed: 12/11/2022] Open
Affiliation(s)
- Milad Mohammadi
- Department of Anaesthesiology, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Beatrice Oehler
- Department of Anaesthesiology, University Hospital of Wuerzburg, Wuerzburg, Germany.,Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Jan Kloka
- Department of Anaesthesiology, University Hospital of Wuerzburg, Wuerzburg, Germany.,Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Corinna Martin
- Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Alexander Brack
- Department of Anaesthesiology, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Robert Blum
- Institute of Clinical Neurobiology, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Heike L Rittner
- Department of Anaesthesiology, University Hospital of Wuerzburg, Wuerzburg, Germany
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27
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Ding W, You Z, Shen S, Yang J, Lim G, Doheny JT, Zhu S, Zhang Y, Chen L, Mao J. Increased HCN Channel Activity in the Gasserian Ganglion Contributes to Trigeminal Neuropathic Pain. THE JOURNAL OF PAIN 2018; 19:626-634. [PMID: 29366880 PMCID: PMC5972061 DOI: 10.1016/j.jpain.2018.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/15/2017] [Accepted: 01/03/2018] [Indexed: 12/27/2022]
Abstract
Orofacial neuropathic pain caused by trigeminal nerve injury is a debilitating condition with limited therapeutic options. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels regulate neuronal excitability and are involved in the development and maintenance of chronic pain. However, the effect of HCN channel activity in the Gasserian ganglion on trigeminal neuropathic pain has not been examined. We evaluated nociceptive behaviors after microinjection of the HCN channel blockers ZD7288 or ivabradine into the Gasserian ganglion in rats with trigeminal nerve injury. Both blockers dose-dependently ameliorated evoked and spontaneous nociceptive behavior in rats with trigeminal neuropathic pain. Moreover, the clinically available HCN channel blocker ivabradine showed a prolonged antinociceptive effect. In the Gasserian ganglion, HCN1 and HCN2 are major HCN isoforms. After trigeminal nerve injury, the counts of HCN1 as well as HCN2 immuno-positive punctae were increased in the ipsilateral Gasserian ganglions. These results indicate that the increased HCN channel activity in the Gasserian ganglion directly contributes to neuropathic pain resulting from trigeminal nerve injury. PERSPECTIVE Trigeminal nerve damage-induced orofacial pain is severe and more resistant to standard pharmacological treatment than other types of neuropathic pain. Our study suggests that targeting HCN channel activities in the Gasserian ganglion may provide an alternative treatment of trigeminal neuropathy including trigeminal neuralgia.
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Affiliation(s)
- Weihua Ding
- MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; The First Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Zerong You
- MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Shiqian Shen
- MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jinsheng Yang
- MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Grewo Lim
- MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jason T Doheny
- MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Shengmei Zhu
- The First Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Yi Zhang
- MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Lucy Chen
- MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jianren Mao
- MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
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Moran MM, Szallasi A. Targeting nociceptive transient receptor potential channels to treat chronic pain: current state of the field. Br J Pharmacol 2018; 175:2185-2203. [PMID: 28924972 PMCID: PMC5980611 DOI: 10.1111/bph.14044] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 08/27/2017] [Accepted: 09/03/2017] [Indexed: 12/12/2022] Open
Abstract
Control of chronic pain is frequently inadequate and/or associated with intolerable adverse effects, prompting a frantic search for new therapeutics and new therapeutic targets. Nearly two decades of preclinical and clinical research supports the involvement of transient receptor potential (TRP) channels in temperature perception, nociception and sensitization. Although there has been considerable excitement around the therapeutic potential of this channel family since the cloning and identification of TRPV1 cation channels as the capsaicin receptor more than 20 years ago, only modulators of a few channels have been tested clinically. TRPV1 channel antagonists have suffered from side effects related to the channel's role in temperature sensation; however, high dose formulations of capsaicin have reached the market and shown therapeutic utility. A number of potent, small molecule antagonists of TRPA1 channels have recently advanced into clinical trials for the treatment of inflammatory and neuropathic pain, and TRPM8 antagonists are following closely behind for cold allodynia. TRPV3, TRPV4, TRPM2 and TRPM3 channels have also been of significant interest. This review discusses the preclinical promise and status of novel analgesic agents that target TRP channels and the challenges that these compounds may face in development and clinical practice. LINKED ARTICLES This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.
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Affiliation(s)
| | - Arpad Szallasi
- Clinical LaboratoriesBaptist Medical CenterJacksonvilleFLUSA
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Bai J, Liu F, Wu LF, Wang YF, Li XQ. Attenuation of TRPV1 by AMG-517 after nerve injury promotes peripheral axonal regeneration in rats. Mol Pain 2018; 14:1744806918777614. [PMID: 29768956 PMCID: PMC6009083 DOI: 10.1177/1744806918777614] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Aims The main objective was to investigate the effects of the transient receptor potential cation channel subfamily V member 1 (TRPV1) on nerve regeneration following sciatic transection injury by functional blockage of TRPV1 using AMG-517, a specific blocker of TRPV1. Methods AMG-517 was injected into the area surrounding ipsilateral lumbar dorsal root ganglia 30 min after unilateral sciatic nerve transection. The number of sciatic axons and the expression of growth-associated protein-43 (GAP-43) and glial fibrillary acidic protein was examined using semithin sections, Western blot, and immunofluorescence analyses. Results Blockage of TRPV1 with AMG-517 markedly promoted axonal regeneration, especially at two weeks after sciatic injury; the number of axons was similar to the uninjured control group. After sciatic nerve transection, expression of glial fibrillary acidic protein was decreased and GAP-43 was increased at the proximal stump. However, the expression of both glial fibrillary acidic protein and GAP-43 increased significantly in AMG-517-treated groups. Conclusions TRPV1 may be an important therapeutic target to promote peripheral nerve regeneration after injury.
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Affiliation(s)
- Juan Bai
- 1 Department of Pathophysiology, School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Fu Liu
- 1 Department of Pathophysiology, School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Li-Fei Wu
- 1 Department of Pathophysiology, School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Ya-Fang Wang
- 1 Department of Pathophysiology, School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Xia-Qing Li
- 1 Department of Pathophysiology, School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, Shanxi, China
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Sapio MR, Neubert JK, LaPaglia DM, Maric D, Keller JM, Raithel SJ, Rohrs EL, Anderson EM, Butman JA, Caudle RM, Brown DC, Heiss JD, Mannes AJ, Iadarola MJ. Pain control through selective chemo-axotomy of centrally projecting TRPV1+ sensory neurons. J Clin Invest 2018; 128:1657-1670. [PMID: 29408808 DOI: 10.1172/jci94331] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 02/01/2018] [Indexed: 11/17/2022] Open
Abstract
Agonists of the vanilloid receptor transient vanilloid potential 1 (TRPV1) are emerging as highly efficacious nonopioid analgesics in preclinical studies. These drugs selectively lesion TRPV1+ primary sensory afferents, which are responsible for the transmission of many noxious stimulus modalities. Resiniferatoxin (RTX) is a very potent and selective TRPV1 agonist and is a promising candidate for treating many types of pain. Recent work establishing intrathecal application of RTX for the treatment of pain resulting from advanced cancer has demonstrated profound analgesia in client-owned dogs with osteosarcoma. The present study uses transcriptomics and histochemistry to examine the molecular mechanism of RTX action in rats, in clinical canine subjects, and in 1 human subject with advanced cancer treated for pain using intrathecal RTX. In all 3 species, we observe a strong analgesic action, yet this was accompanied by limited transcriptional alterations at the level of the dorsal root ganglion. Functional and neuroanatomical studies demonstrated that intrathecal RTX largely spares susceptible neuronal perikarya, which remain active peripherally but unable to transmit signals to the spinal cord. The results demonstrate that central chemo-axotomy of the TRPV1+ afferents underlies RTX analgesia and refine the neurobiology underlying effective clinical use of TRPV1 agonists for pain control.
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Affiliation(s)
- Matthew R Sapio
- Clinical Center, Department of Perioperative Medicine, NIH, Bethesda, Maryland, USA
| | - John K Neubert
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Danielle M LaPaglia
- Clinical Center, Department of Perioperative Medicine, NIH, Bethesda, Maryland, USA
| | - Dragan Maric
- Flow Cytometry Core Facility, NIH, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA
| | - Jason M Keller
- Clinical Center, Department of Perioperative Medicine, NIH, Bethesda, Maryland, USA
| | - Stephen J Raithel
- Clinical Center, Department of Perioperative Medicine, NIH, Bethesda, Maryland, USA
| | - Eric L Rohrs
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Ethan M Anderson
- Department of Oral and Maxillofacial Surgery, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - John A Butman
- Clinical Center, Radiology and Imaging Services, NIH, Bethesda, Maryland, USA
| | - Robert M Caudle
- Department of Oral and Maxillofacial Surgery, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Dorothy C Brown
- Veterinary Clinical Investigations Center, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - John D Heiss
- Surgical Neurology Branch, NIH, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA
| | - Andrew J Mannes
- Clinical Center, Department of Perioperative Medicine, NIH, Bethesda, Maryland, USA
| | - Michael J Iadarola
- Clinical Center, Department of Perioperative Medicine, NIH, Bethesda, Maryland, USA
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Kozłowska A, Mikołajczyk A, Majewski M. Distribution and neurochemistry of porcine urinary bladder-projecting sensory neurons in subdomains of the dorsal root ganglia: A quantitative analysis. Ann Anat 2017; 216:36-51. [PMID: 29169841 DOI: 10.1016/j.aanat.2017.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 12/25/2022]
Abstract
The aim of the present study has been to verify the inter- and intraganglionic distribution pattern of porcine urinary bladder-projecting (UBP) neurons localized in the sacral dorsal root ganglia (DRGs). The morphology and chemical phenotype of these cells have also been investigated. These neurons were visualized using the fluorescent tracer Fast Blue (FB) which was injected bilaterally into the urinary bladder wall of five juvenile female pigs. The intraganglionic distribution showed that small- and medium-sized FB+ perikarya were mainly located in the central (S3-S4) and periphero-central (S2) region of the ganglia, while large cells were heterogeneously distributed. Immunohistochemistry revealed that the most frequently observed markers in small and medium-sized UBP perikarya were: neurofilament 200, lectin from Bandeiraea simplicifolia (Griffonia simplicifolia) isolectin B4, substance P, calcitonin gene-related peptide, pituitary adenylate cyclase-activating polypeptide and transient receptor potential vanilloid 1. Moreover, UBP neurons containing these substances were also mainly observed in the central and periphero-central region of the ganglion. Differences in the percentage of traced cells and their neuropeptide content were observed between the S2, S3 and S4 DRGs. In conclusion, the present study, for the first time, describes the arrangement of UBP DRGs neurons within particular subdomains of sacral ganglia, taking into account their size and chemical phenotype.
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Affiliation(s)
- Anna Kozłowska
- Department of Human Physiology, School of Medicine, Collegium Medicicum, University of Warmia and Mazury Olsztyn, Poland.
| | - Anita Mikołajczyk
- Department of Public Health, Epidemiology and Microbiology, School of Medicine, Collegium Medicicum, University of Warmia and Mazury Olsztyn, Poland
| | - Mariusz Majewski
- Department of Human Physiology, School of Medicine, Collegium Medicicum, University of Warmia and Mazury Olsztyn, Poland
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Minimally invasive probes for programmed microfluidic delivery of molecules in vivo. Curr Opin Pharmacol 2017; 36:78-85. [PMID: 28892801 DOI: 10.1016/j.coph.2017.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 08/19/2017] [Accepted: 08/21/2017] [Indexed: 01/06/2023]
Abstract
Site-specific drug delivery carries many advantages of systemic administration, but is rarely used in the clinic. One limiting factor is the relative invasiveness of the technology to locally deliver compounds. Recent advances in materials science and electrical engineering allow for the development of ultraminiaturized microfluidic channels based on soft materials to create flexible probes capable of deep tissue targeting. A diverse set of mechanics, including micro-pumps and functional materials, used to deliver the drugs can be paired with wireless electronics for self-contained and programmable operation. These first iterations of minimally invasive fluid delivery devices foreshadow important advances needed for clinical translation.
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Pecze L, Viskolcz B, Oláh Z. Molecular Surgery Concept from Bench to Bedside: A Focus on TRPV1+ Pain-Sensing Neurons. Front Physiol 2017. [PMID: 28626428 PMCID: PMC5455100 DOI: 10.3389/fphys.2017.00378] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
"Molecular neurosurgery" is emerging as a new medical concept, and is the combination of two partners: (i) a molecular neurosurgery agent, and (ii) the cognate receptor whose activation results in the selective elimination of a specific subset of neurons in which this receptor is endogenously expressed. In general, a molecular surgery agent is a selective and potent ligand, and the target is a specific cell type whose elimination is desired through the molecular surgery procedure. These target cells have the highest innate sensitivity to the molecular surgery agent usually due to the highest receptor density being in their plasma membrane. The interaction between the ligand and its receptor evokes an overactivity of the receptor. If the receptor is a ligand-activated non-selective cation channel, the overactivity of receptor leads to excess Ca2+ and Na+ influx into the cell and finally cell death. One of the best known examples of such an interaction is the effect of ultrapotent vanilloids on TRPV1-expressing pain-sensing neurons. One intrathecal resiniferatoxin (RTX) dose allows for the receptor-mediated removal of TRPV1+ neurons from the peripheral nervous system. The TRPV1 receptor-mediated ion influx induces necrotic processes, but only in pain-sensing neurons, and usually within an hour. Besides that, target-specific apoptotic processes are also induced. Thus, as a nano-surgery scalpel, RTX removes the neurons responsible for generating pain and inflammation from the peripheral nervous system providing an option in clinical management for the treatment of morphine-insensitive pain conditions. In the future, the molecular surgery concept can also be exploited in cancer research for selectively targeting the specific tumor cell.
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Affiliation(s)
- László Pecze
- Unit of Anatomy, Department of Medicine, University of FribourgFribourg, Switzerland
| | - Béla Viskolcz
- Institute of Chemistry, Faculty of Materials Science and Engineering, University of MiskolcMiskolc, Hungary
| | - Zoltán Oláh
- Institute of Chemistry, Faculty of Materials Science and Engineering, University of MiskolcMiskolc, Hungary.,Acheuron Ltd.Szeged, Hungary
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Ison SH, Clutton RE, Di Giminiani P, Rutherford KMD. A Review of Pain Assessment in Pigs. Front Vet Sci 2016; 3:108. [PMID: 27965968 PMCID: PMC5124671 DOI: 10.3389/fvets.2016.00108] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 11/15/2016] [Indexed: 11/13/2022] Open
Abstract
There is a moral obligation to minimize pain in pigs used for human benefit. In livestock production, pigs experience pain caused by management procedures, e.g., castration and tail docking, injuries from fighting or poor housing conditions, “management diseases” like mastitis or streptococcal meningitis, and at parturition. Pigs used in biomedical research undergo procedures that are regarded as painful in humans, but do not receive similar levels of analgesia, and pet pigs also experience potentially painful conditions. In all contexts, accurate pain assessment is a prerequisite in (a) the estimation of the welfare consequences of noxious interventions and (b) the development of more effective pain mitigation strategies. This narrative review identifies the sources of pain in pigs, discusses the various assessment measures currently available, and proposes directions for future investigation.
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Affiliation(s)
- Sarah H Ison
- Animal Behaviour and Welfare, Animal and Veterinary Sciences, Scotland's Rural College (SRUC), Edinburgh, UK; Easter Bush Veterinary Centre, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Midlothian, UK
| | - R Eddie Clutton
- Easter Bush Veterinary Centre, Royal (Dick) School of Veterinary Studies, The University of Edinburgh , Midlothian , UK
| | - Pierpaolo Di Giminiani
- Food and Rural Development, School of Agriculture, Newcastle University , Newcastle upon Tyne , UK
| | - Kenneth M D Rutherford
- Animal Behaviour and Welfare, Animal and Veterinary Sciences, Scotland's Rural College (SRUC) , Edinburgh , UK
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TRPV1: A Target for Rational Drug Design. Pharmaceuticals (Basel) 2016; 9:ph9030052. [PMID: 27563913 PMCID: PMC5039505 DOI: 10.3390/ph9030052] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/12/2016] [Accepted: 08/18/2016] [Indexed: 12/18/2022] Open
Abstract
Transient Receptor Potential Vanilloid 1 (TRPV1) is a non-selective, Ca2+ permeable cation channel activated by noxious heat, and chemical ligands, such as capsaicin and resiniferatoxin (RTX). Many compounds have been developed that either activate or inhibit TRPV1, but none of them are in routine clinical practice. This review will discuss the rationale for antagonists and agonists of TRPV1 for pain relief and other conditions, and strategies to develop new, better drugs to target this ion channel, using the newly available high-resolution structures.
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Aizawa N, Fukuhara H, Fujimura T, Homma Y, Igawa Y. Direct influence of systemic desensitization by resiniferatoxin on the activities of Aδ- and C-fibers in the rat primary bladder mechanosensitive afferent nerves. Int J Urol 2016; 23:952-956. [DOI: 10.1111/iju.13181] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 07/06/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Naoki Aizawa
- Department of Continence Medicine; The University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Hiroshi Fukuhara
- Department of Urology; The University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Tetsuya Fujimura
- Department of Urology; The University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Yukio Homma
- Department of Urology; The University of Tokyo Graduate School of Medicine; Tokyo Japan
| | - Yasuhiko Igawa
- Department of Continence Medicine; The University of Tokyo Graduate School of Medicine; Tokyo Japan
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Pleticha J, Maus TP, Beutler AS. Future Directions in Pain Management: Integrating Anatomically Selective Delivery Techniques With Novel Molecularly Selective Agents. Mayo Clin Proc 2016; 91:522-33. [PMID: 27046525 DOI: 10.1016/j.mayocp.2016.02.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/19/2016] [Accepted: 02/22/2016] [Indexed: 01/12/2023]
Abstract
Treatment for chronic, locoregional pain ranks among the most prevalent unmet medical needs. The failure of systemic analgesic drugs, such as opioids, is often due to their off-target toxicity, development of tolerance, and abuse potential. Interventional pain procedures provide target specificity but lack pharmacologically selective agents with long-term efficacy. Gene therapy vectors are a new tool for the development of molecularly selective pain therapies, which have already been proved to provide durable analgesia in preclinical models. Taken together, advances in image-guided delivery and gene therapy may lead to a new class of dual selective analgesic treatments integrating the molecular selectivity of analgesic genes with the anatomic selectivity of interventional delivery techniques.
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Affiliation(s)
- Josef Pleticha
- Department of Anesthesiology and Oncology, Mayo Clinic, Rochester, MN
| | | | - Andreas S Beutler
- Department of Anesthesiology and Oncology, Mayo Clinic, Rochester, MN
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