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Pontearso M, Slepicka J, Bhattacharyya A, Spicarova D, Palecek J. Dual effect of anandamide on spinal nociceptive transmission in control and inflammatory conditions. Biomed Pharmacother 2024; 173:116369. [PMID: 38452657 DOI: 10.1016/j.biopha.2024.116369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/26/2024] [Accepted: 02/28/2024] [Indexed: 03/09/2024] Open
Abstract
Anandamide (AEA) is an important modulator of nociception in the spinal dorsal horn, acting presynaptically through Cannabinoid (CB1) and Transient receptor potential vanilloid (TRPV1) receptors. The role of AEA (1 µM, 10 µM, and 30 µM) application on the modulation of nociceptive synaptic transmission under control and inflammatory conditions was studied by recording miniature excitatory postsynaptic currents (mEPSCs) from neurons in spinal cord slices. Inhibition of the CB1 receptors by PF514273, TRPV1 by SB366791, and the fatty acid amide hydrolase (FAAH) by URB597 was used. Under naïve conditions, the AEA application did not affect the mEPSCs frequency (1.43±0.12 Hz) when all the recorded neurons were considered. The mEPSC frequency increased (180.0±39.2%) only when AEA (30 µM) was applied with PF514273 and URB597. Analysis showed that one sub-population of neurons had synaptic input inhibited (39.1% of neurons), the second excited (43.5%), whereas 8.7% showed a mixed effect and 8.7% did not respond to the AEA. With inflammation, the AEA effect was highly inhibitory (72.7%), while the excitation was negligible (9.1%), and 18.2% were not modulated. After inflammation, more neurons (45.0%) responded even to low AEA by mEPSC frequency increase with PF514273/URB597 present. AEA-induced dual (excitatory/inhibitory) effects at the 1st nociceptive synapse should be considered when developing analgesics targeting the endocannabinoid system. These findings contrast the clear inhibitory effects of the AEA precursor 20:4-NAPE application described previously and suggest that modulation of endogenous AEA production may be more favorable for analgesic treatments.
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Affiliation(s)
- Monica Pontearso
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jakub Slepicka
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Anirban Bhattacharyya
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Diana Spicarova
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jiri Palecek
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
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2
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Iglesias LP, Fernandes HB, de Miranda AS, Perez MM, Faccioli LH, Sorgi CA, Bertoglio LJ, Aguiar DC, Wotjak CT, Moreira FA. TRPV1 modulation of contextual fear memory depends on stimulus intensity and endocannabinoid signalling in the dorsal hippocampus. Neuropharmacology 2023; 224:109314. [PMID: 36336070 DOI: 10.1016/j.neuropharm.2022.109314] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 10/21/2022] [Accepted: 10/28/2022] [Indexed: 11/05/2022]
Abstract
The transient receptor potential vanilloid type-1 (TRPV1) channels have been implicated in the modulation of aversive responses. The endocannabinoid anandamide acts as an endogenous TRPV1 agonist, exerting opposite functions at TRPV1 and type-1 cannabinoid receptors (CB1R). Here we tested the hypothesis that hippocampal TRPV1 modulates contextual fear memory retrieval and investigated the influence of the aversive stimulus intensity as well as the role of endocannabinoid signaling. Male C57BL/6J mice were tested for contextual fear memory after low-, moderate-, or high-intensity shock protocols. The selective TRPV1 blockers SB366791 (1-10 nmol) and 6-I-NC (2 nmol) were infused via intra-dorsal hippocampus before the retrieval test session. The local levels of endocannabinoids and Arc and Zif268 mRNAs, involved in synaptic plasticity and memory, were quantified. First, both TRPV1 blockers reduced memory retrieval in animals exposed to moderate or high (but not low) intensity training protocols. In the second series of results, the magnitude of the freezing responses positively correlated with the hippocampal anandamide levels; TRPV1 and CB1R were found co-localized in this brain region; and the CB1R antagonist, AM251, prevented the effects of SB366791. Thus, endocannabinoid signaling possibly mediates the effects of TRPV1 blockers. Finally, inhibition of memory retrieval by TRPV1 blockers increased Arc and Zif268 mRNAs and impaired fear memory reinstatement. In conclusion, the modulation of fear memories by dorsal hippocampal TRPV1 channels may depend on the aversive stimulus intensity and occur via anandamide/CB1 signaling. Moreover, TRPV1 blockers promote Arc and Zif268 transcription, with subsequent attenuation of aversive memory reinstatement.
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Affiliation(s)
- Lia P Iglesias
- Graduate School in Neuroscience and Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Heliana B Fernandes
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Aline S de Miranda
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Malena M Perez
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Lucia H Faccioli
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Carlos A Sorgi
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Leandro J Bertoglio
- Department of Pharmacology, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Daniele C Aguiar
- Graduate School in Neuroscience and Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Carsten T Wotjak
- Central Nervous System Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach Riß, Germany
| | - Fabrício A Moreira
- Graduate School in Neuroscience and Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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3
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TRPV1: A Common Denominator Mediating Antinociceptive and Antiemetic Effects of Cannabinoids. Int J Mol Sci 2022; 23:ijms231710016. [PMID: 36077412 PMCID: PMC9456209 DOI: 10.3390/ijms231710016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 12/19/2022] Open
Abstract
The most common medicinal claims for cannabis are relief from chronic pain, stimulation of appetite, and as an antiemetic. However, the mechanisms by which cannabis reduces pain and prevents nausea and vomiting are not fully understood. Among more than 450 constituents in cannabis, the most abundant cannabinoids are Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Cannabinoids either directly or indirectly modulate ion channel function. Transient receptor potential vanilloid 1 (TRPV1) is an ion channel responsible for mediating several modalities of pain, and it is expressed in both the peripheral and the central pain pathways. Activation of TRPV1 in sensory neurons mediates nociception in the ascending pain pathway, while activation of TRPV1 in the central descending pain pathway, which involves the rostral ventral medulla (RVM) and the periaqueductal gray (PAG), mediates antinociception. TRPV1 channels are thought to be implicated in neuropathic/spontaneous pain perception in the setting of impaired descending antinociceptive control. Activation of TRPV1 also can cause the release of calcitonin gene-related peptide (CGRP) and other neuropeptides/neurotransmitters from the peripheral and central nerve terminals, including the vagal nerve terminal innervating the gut that forms central synapses at the nucleus tractus solitarius (NTS). One of the adverse effects of chronic cannabis use is the paradoxical cannabis-induced hyperemesis syndrome (HES), which is becoming more common, perhaps due to the wider availability of cannabis-containing products and the chronic use of products containing higher levels of cannabinoids. Although, the mechanism of HES is unknown, the effective treatment options include hot-water hydrotherapy and the topical application of capsaicin, both activate TRPV1 channels and may involve the vagal-NTS and area postrema (AP) nausea and vomiting pathway. In this review, we will delineate the activation of TRPV1 by cannabinoids and their role in the antinociceptive/nociceptive and antiemetic/emetic effects involving the peripheral, spinal, and supraspinal structures.
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Jamieson BB, Kim JS, Iremonger KJ. Cannabinoid and vanilloid pathways mediate opposing forms of synaptic plasticity in corticotropin-releasing hormone neurons. J Neuroendocrinol 2022; 34:e13084. [PMID: 35034400 DOI: 10.1111/jne.13084] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 01/18/2023]
Abstract
Activity-dependent release of retrograde signaling molecules form micro-feedback loops to regulate synaptic function in neural circuits. Single neurons can release multiple forms of these signaling molecules, including endocannabinoids and endovanilloids, which act via cannabinoid (CB) receptors and transient receptor potential vanilloid 1 (TRPV1) receptors. In hypothalamic corticotrophin-releasing hormone (CRH) neurons, endocannabinoids acting via CB1 receptors have been shown to play an important role in regulating excitability and hence stress hormone secretion. However, the importance of endovanilloid signaling in CRH neurons is currently unclear. Here, we show that, in response to postsynaptic depolarization, CRH neurons release endocannabinoid/endovanilloid molecules that can activate CB1 and TRPV1 receptors. Activation of CB1 receptors suppresses glutamate neurotransmission whereas activation of TRPV1 enhances spontaneous glutamate transmission. However, the excitatory effects of TRPV1 are normally masked by the inhibitory effects of CB1. When the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG) was inhibited, this revealed tonic activation of CB1 receptors, suggesting tonic endocannabinoid release. However, we found no evidence for tonic activation of TRPV1 receptors under similar conditions. These findings show that activation of CRH neurons can drive the release of signaling molecules that activate parallel endocannabinoid and endovanilloid receptor pathways to mediate opposing forms of synaptic plasticity.
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Affiliation(s)
- Bradley B Jamieson
- Centre for Neuroendocrinology, Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Joon S Kim
- Centre for Neuroendocrinology, Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Karl J Iremonger
- Centre for Neuroendocrinology, Department of Physiology, University of Otago, Dunedin, New Zealand
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5
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Iglesias LP, Aguiar DC, Moreira FA. TRPV1 blockers as potential new treatments for psychiatric disorders. Behav Pharmacol 2022; 33:2-14. [PMID: 33136616 DOI: 10.1097/fbp.0000000000000603] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The transient receptor potential vanilloid-1 channel (TRPV1) is responsible for decoding physical and chemical stimuli. TRPV1 is activated by capsaicin (a compound from chili peppers), heat (above 43°C) and acid environment, playing a major role in pain, inflammation and body temperature. Molecular and histological studies have suggested TRPV1 expression in specific brain regions, where it can be activated primarily by the endocannabinoid anandamide, fostering studies on its potential role in psychiatric disorders. TRPV1 blockers are effective in various animal models predictive of anxiolytic and antipanic activities, in addition to reducing conditioned fear. In models of antidepressant activity, these compounds reduce behavioral despair and promote active stress-coping behavior. TRPV1 blockers also reduce the effects of certain drugs of abuse and revert behavioral changes in animal models of neurodevelopmental disorders. The main limiting factor in developing TRPV1 blockers as therapeutic agents concerns their effects on body temperature, particularly hyperthermia. New compounds, which block specific states of the channel, could represent an alternative. Moreover, compounds blocking both TRPV1 and the anandamide-hydrolyzing enzyme, fatty acid amide hydrolase (FAAH), termed dual TRPV1/FAAH blockers, have been investigated with promising results. Overall, preclinical studies yield favorable results with TRPV1 blockers in animal models of psychiatric disorders.
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Affiliation(s)
- Lia P Iglesias
- Department of Pharmacology, Graduate School of Neuroscience
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gera, Brazil
| | - Daniele C Aguiar
- Department of Pharmacology, Graduate School of Neuroscience
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gera, Brazil
| | - Fabrício A Moreira
- Department of Pharmacology, Graduate School of Neuroscience
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gera, Brazil
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Karimi SA, Kazemi F, Komaki H, Kourosh Arami M, Shahidi S, Komaki A. Electrophysiological study of the interactive role of the cannabinoid breakdown inhibitors and L-type calcium channels on granular neurons in the hippocampal dentate gyrus in rats. Neurol Res 2021; 44:446-454. [PMID: 34781846 DOI: 10.1080/01616412.2021.2004364] [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: 10/19/2022]
Abstract
The interaction between L-type voltage-dependent Ca2+ channels and the endocannabinoid system (eCs) in synaptic plasticity is controversial. In the present research, the impact of acute administration of URB597, as an endocannabinoid breakdown inhibitor, was evaluated after chronic injection of verapamil, as a Ca2+ channels blocker, on inducing long-term potentiation (LTP) in the rat's hippocampal dentate gyrus (DG). Treatment of male Wistar rats was done using intraperitoneal(i.p) injection of verapamil hydrochloride (n = 8) and saline (n = 10), as the solvent of verapamil once a day within 13 days. Anesthetization was done by i.p injection of urethane and the rats were located in the stereotaxic apparatus for surgery, electrode implantation, and field potential recording. After observing a steady-state baseline response, saline or URB597 were injected (n = 9). Measurement of the population spike (PS) amplitude and slope of field excitatory postsynaptic potentials (fEPSPs) in the DG region was performed as a result of perforant pathway (PP) stimulation. Our treatments could inhibit LTP. Our results indicated that the chronic administration of verapamil produced a significant decrease in the slope of fEPSP and PS amplitude. Also, acute URB597 administration decreased the slope of fEPSP and PS amplitude compared to the saline group. Moreover, URB597 administration in combination with chronic administration of verapamil produced a greater decrease in fEPSP slope and PS amplitude than the saline group. These findings indicated that verapamil and URB597 disrupted LTP induction in the DG. Moreover, an interaction was observed between Ca2+ channels and eCs. Therefore, the eCs possibly play a selective role in synaptic plasticity.
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Affiliation(s)
- Seyed Asaad Karimi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Fatemeh Kazemi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hamidreza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Masoumeh Kourosh Arami
- Department of Basic Sciences, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Siamak Shahidi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
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Winters BL, Vaughan CW. Mechanisms of endocannabinoid control of synaptic plasticity. Neuropharmacology 2021; 197:108736. [PMID: 34343612 DOI: 10.1016/j.neuropharm.2021.108736] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/13/2023]
Abstract
The endogenous cannabinoid transmitter system regulates synaptic transmission throughout the nervous system. Unlike conventional transmitters, specific stimuli induce synthesis of endocannabinoids (eCBs) in the postsynaptic neuron, and these travel backwards to modulate presynaptic inputs. In doing so, eCBs can induce short-term changes in synaptic strength and longer-term plasticity. While this eCB regulation is near ubiquitous, it displays major regional and synapse specific variations with different synapse specific forms of short-versus long-term plasticity throughout the brain. These differences are due to the plethora of pre- and postsynaptic mechanisms which have been implicated in eCB signalling, the intricacies of which are only just being realised. In this review, we shall describe the current understanding and highlight new advances in this area, with a focus on the retrograde action of eCBs at CB1 receptors (CB1Rs).
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Affiliation(s)
- Bryony Laura Winters
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia.
| | - Christopher Walter Vaughan
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia
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Mizuno I, Matsuda S. The role of endocannabinoids in consolidation, retrieval, reconsolidation, and extinction of fear memory. Pharmacol Rep 2021; 73:984-1003. [PMID: 33954935 DOI: 10.1007/s43440-021-00246-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/26/2021] [Accepted: 03/07/2021] [Indexed: 12/19/2022]
Abstract
Endocannabinoids are involved in various physiological functions, including synaptic plasticity and memory, and some psychiatric disorders, such as posttraumatic stress disorder (PTSD), through the activation of cannabinoid (CB) receptors. Patients with PTSD often show excessive fear memory and impairment of fear extinction (FE). It has been reported that the stability of acquired fear memory is altered through multiple memory stages, such as consolidation and reconsolidation. FE also affects the stability of fear memory. Each stage of fear memory formation and FE are regulated by different molecular mechanisms, including the CB system. However, to the best of our knowledge, no review summarizes the role of the CB system during each stage of fear memory formation and FE. In this review, we summarize the roles of endocannabinoids in fear memory formation and FE. Moreover, based on the summary, we propose a new hypothesis for the role of endocannabinoids in fear regulation, and discuss treatment for PTSD using CB system-related drugs.
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Affiliation(s)
- Ikumi Mizuno
- Department of Pharmacotherapeutics, Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan
| | - Shingo Matsuda
- Department of Pharmacotherapeutics, Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan. .,Department of Cognitive Behavioral Physiology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba, Chiba, 260-8670, Japan. .,Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo, 187-8502, Japan.
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Restoring glutamate homeostasis in the nucleus accumbens via endocannabinoid-mimetic drug prevents relapse to cocaine seeking behavior in rats. Neuropsychopharmacology 2021; 46:970-981. [PMID: 33514875 PMCID: PMC8115336 DOI: 10.1038/s41386-021-00955-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 12/13/2020] [Accepted: 12/29/2020] [Indexed: 12/23/2022]
Abstract
Impaired glutamate homeostasis is a key characteristic of the neurobiology of drug addiction in rodent models and contributes to the vulnerability to relapse to drug seeking. Although disrupted astrocytic and presynaptic regulation of glutamate release has been considered to constitute with impaired glutamate homeostasis in rodent model of drug relapse, the involvement of endocannabinoids (eCBs) in this neurobiological process has remained largely unknown. Here, using cocaine self-administration in rats, we investigated the role of endocannabinoids in impaired glutamate homeostasis in the core of nucleus accumbens (NAcore), which was indicated by augmentation of spontaneous synaptic glutamate release, downregulation of metabotropic glutamate receptor 2/3 (mGluR2/3), and mGluR5-mediated astrocytic glutamate release. We found that the endocannabinoid, anandamide (AEA), rather than 2-arachidonoylglycerol elicited glutamate release through presynaptic transient receptor potential vanilloid 1 (TRPV1) and astrocytic cannabinoid type-1 receptors (CB1Rs) in the NAcore of saline-yoked rats. In rats with a history of cocaine self-administration and extinction training, AEA failed to alter synaptic glutamate release in the NAcore, whereas CB1R-mediated astrocytic glutamate release by AEA remained functional. In order to induce increased astrocytic glutamate release via exogenous AEA, (R)-methanandamide (methAEA, a metabolically stable form of AEA) was chronically infused in the NAcore via osmotic pumps during extinction training. Restoration of mGluR2/3 function and mGluR5-mediated astrocytic glutamate release was observed after chronic methAEA infusion. Additionally, priming or cue-induced reinstatement of cocaine seeking was inhibited in methAEA-infused rats. These results demonstrate that enhancing endocannabinoid signaling is a potential pathway to restore glutamate homeostasis and may represent a promising therapeutic strategy for preventing cocaine relapse.
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Quiñonez‐Bastidas GN, Palomino‐Hernández O, López‐Ortíz M, Rocha‐González HI, González‐Anduaga GM, Regla I, Navarrete A. Antiallodynic effect of PhAR-DBH-Me involves cannabinoid and TRPV1 receptors. Pharmacol Res Perspect 2020; 8:e00663. [PMID: 32965798 PMCID: PMC7510332 DOI: 10.1002/prp2.663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 12/29/2022] Open
Abstract
The antiallodynic effect of PhAR-DBH-Me was evaluated on two models of neuropathic pain, and the potential roles of CB1, CB2, and TRPV1 receptors as molecular targets of PhAR-DBH-Me were studied. Female Wistar rats were submitted to L5/L6 spinal nerve ligation (SNL) or repeated doses of cisplatin (0.1 mg/kg, i.p.) to induce experimental neuropathy. Then, tactile allodynia was determined, and animals were treated with logarithmic doses of PhAR-DBH-Me (3.2-100 mg/kg, i.p.). To evaluate the mechanism of action of PhAR-DBH-Me, in silico studies using crystallized structures of CB1, CB2, and TRPV1 receptors were performed. To corroborate the computational insights, animals were intraperitoneally administrated with antagonists for CB1 (AM-251, 3 mg/kg), CB2 (AM-630, 1 mg/kg), and TRPV1 receptors (capsazepine, 3 mg/kg), 15 min before to PhAR-DBH-Me (100 mg/kg) administration. Vagal stimulation evoked on striated muscle contraction in esophagus, was used to elicited pharmacological response of PhAR-DBH-ME on nervous tissue. Systemic administration of PhAR-DBH-Me reduced the SNL- and cisplatin-induced allodynia. Docking studies suggested that PhAR-DBH-Me acts as an agonist for CB1, CB2, and TRPV1 receptors, with similar affinity to the endogenous ligand anandamide. Moreover antiallodynic effect of PhAR-DBH-Me was partially prevented by administration of AM-251 and AM-630, and completely prevented by capsazepine. Finally, PhAR-DBH-Me decreased the vagally evoked electrical response in esophagus rat. Taken together, results indicate that PhAR-DBH-Me induces an antiallodynic effect through partial activation of CB1 and CB2 receptors, as well as desensitization of TRPV1 receptors. Data also shed light on the novel vanilloid nature of the synthetic compound PhAR-DBH-Me.
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Affiliation(s)
| | - Oscar Palomino‐Hernández
- Computational Biomedicine ‐ Institute for Advanced Simulation (IAS‐5) and Institute of Neuroscience and Medicine (INM‐9)Forschungszentrum JülichJülichGermany
- Department of ChemistryRheinisch‐Westfälische Technische Hochschule AachenAachenGermany
| | - Manuel López‐Ortíz
- Facultad de Estudios Superiores ZaragozaUniversidad Nacional Autónoma de México (UNAM)MéxicoDFMéxico
| | - Héctor Isaac Rocha‐González
- Sección de Estudios de Posgrado e InvestigaciónEscuela Superior de MedicinaInstituto Politécnico NacionalMéxicoCiudad de MéxicoMéxico
| | - Gloria Melisa González‐Anduaga
- Facultad de QuímicaDepartamento de FarmaciaUniversidad Nacional Autónoma de MéxicoCiudad UniversitariaCoyoacánCiudad de MéxicoMéxico
| | - Ignacio Regla
- Facultad de Estudios Superiores ZaragozaUniversidad Nacional Autónoma de México (UNAM)MéxicoDFMéxico
| | - Andrés Navarrete
- Facultad de QuímicaDepartamento de FarmaciaUniversidad Nacional Autónoma de MéxicoCiudad UniversitariaCoyoacánCiudad de MéxicoMéxico
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11
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Uliana DL, Antero LS, Borges-Assis AB, Rosa J, Vila-Verde C, Lisboa SF, Resstel LB. Differential modulation of the contextual conditioned emotional response by CB1 and TRPV1 receptors in the ventromedial prefrontal cortex: Possible involvement of NMDA/nitric oxide-related mechanisms. J Psychopharmacol 2020; 34:1043-1055. [PMID: 32638638 DOI: 10.1177/0269881120928201] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Blockade of cannabinoid CB1 or vanilloid TRPV1 receptors in the ventromedial prefrontal cortex of rats respectively increases or decreases the conditioned emotional response during re-exposure to a context previously paired with footshocks. Although these mechanisms are unknown, they may involve local modulation of glutamatergic and nitrergic signaling. AIM We investigated whether these mechanisms are involved in the reported effects of CB1 and TRPV1 modulation in the ventromedial prefrontal cortex. METHODS Freezing behavior and autonomic parameters were recorded during the conditioned response expression. RESULTS The CB1 receptors antagonist NIDA, or the TRPV1 agonist capsaicin (CPS) in the ventromedial prefrontal cortex increased the conditioned emotional response expression, and these effects were prevented by TRPV1 and CB1 antagonism, respectively. The increased conditioned emotional response evoked by NIDA and CPS were prevented by an NMDA antagonist or a neuronal nitric oxide synthase inhibitor. A nitric oxide scavenger or a soluble guanylate cyclase inhibitor prevented only the NIDA effects and the CPS effect was prevented by a non-selective antioxidant drug, as nitric oxide can also induce reactive oxygen species production. CONCLUSION Our results suggest that CB1 and TRPV1 receptors in the ventromedial prefrontal cortex differently modulate the expression of conditioned emotional response through glutamatergic and nitrergic mechanisms, although different pathways may be involved.
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Affiliation(s)
- Daniela L Uliana
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, USA.,Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Leandro S Antero
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Anna B Borges-Assis
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Jessica Rosa
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Carla Vila-Verde
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Sabrina F Lisboa
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil.,Department of BioMolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil.,National Institute of Science and Technology for Translational Medicine, Brazilian National Council for Scientific and Technological Development, Brasília, Brazil
| | - Leonardo Bm Resstel
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirao Preto, São Paulo, Brazil.,National Institute of Science and Technology for Translational Medicine, Brazilian National Council for Scientific and Technological Development, Brasília, Brazil
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12
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Escelsior A, Sterlini B, Murri MB, Serafini G, Aguglia A, da Silva BP, Corradi A, Valente P, Amore M. Red-hot chili receptors: A systematic review of TRPV1 antagonism in animal models of psychiatric disorders and addiction. Behav Brain Res 2020; 393:112734. [DOI: 10.1016/j.bbr.2020.112734] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 05/19/2020] [Accepted: 05/22/2020] [Indexed: 12/17/2022]
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13
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Hossain MZ, Ando H, Unno S, Kitagawa J. Targeting Peripherally Restricted Cannabinoid Receptor 1, Cannabinoid Receptor 2, and Endocannabinoid-Degrading Enzymes for the Treatment of Neuropathic Pain Including Neuropathic Orofacial Pain. Int J Mol Sci 2020; 21:E1423. [PMID: 32093166 PMCID: PMC7073137 DOI: 10.3390/ijms21041423] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 02/06/2023] Open
Abstract
Neuropathic pain conditions including neuropathic orofacial pain (NOP) are difficult to treat. Contemporary therapeutic agents for neuropathic pain are often ineffective in relieving pain and are associated with various adverse effects. Finding new options for treating neuropathic pain is a major priority in pain-related research. Cannabinoid-based therapeutic strategies have emerged as promising new options. Cannabinoids mainly act on cannabinoid 1 (CB1) and 2 (CB2) receptors, and the former is widely distributed in the brain. The therapeutic significance of cannabinoids is masked by their adverse effects including sedation, motor impairment, addiction and cognitive impairment, which are thought to be mediated by CB1 receptors in the brain. Alternative approaches have been developed to overcome this problem by selectively targeting CB2 receptors, peripherally restricted CB1 receptors and endocannabinoids that may be locally synthesized on demand at sites where their actions are pertinent. Many preclinical studies have reported that these strategies are effective for treating neuropathic pain and produce no or minimal side effects. Recently, we observed that inhibition of degradation of a major endocannabinoid, 2-arachydonoylglycerol, can attenuate NOP following trigeminal nerve injury in mice. This review will discuss the above-mentioned alternative approaches that show potential for treating neuropathic pain including NOP.
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Affiliation(s)
- Mohammad Zakir Hossain
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan; (S.U.); (J.K.)
| | - Hiroshi Ando
- Department of Biology, School of Dentistry, Matsumoto Dental University, 1780 Gobara, Hirooka, Shiojiri, Nagano 399-0781, Japan;
| | - Shumpei Unno
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan; (S.U.); (J.K.)
| | - Junichi Kitagawa
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan; (S.U.); (J.K.)
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Philpott HT, McDougall JJ. Combatting joint pain and inflammation by dual inhibition of monoacylglycerol lipase and cyclooxygenase-2 in a rat model of osteoarthritis. Arthritis Res Ther 2020; 22:9. [PMID: 31937359 PMCID: PMC6961325 DOI: 10.1186/s13075-020-2096-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 01/05/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Endocannabinoids are showing great promise as effective mediators for controlling joint inflammation and pain. One strategy that could be harnessed to promote endogenous cannabinoid function is to inhibit the enzymatic break down of endocannabinoids locally in the joint. KML29 is an inhibitor of monoacylglycerol lipase (MAGL) activity which has been shown to promote increased 2-arachodonylglycerol (2-AG) levels in the circulation and in peripheral tissues. It is also known that 2-AG can be metabolised via the cyclo-oxygenase-2 (COX-2) pathway leading to the production of pro-inflammatory prostaglandins, which may counteract the effects of 2-AG. Therefore, this study examined the effect of KML29 alone as well as in combination with low-dose celecoxib (CXB) on joint pain and inflammation in the monoiodoacetate (MIA) model of osteoarthritis (OA) pain. METHODS Injection of MIA (3 mg) into the knee joints of male Wistar rats was used to model OA pain, inflammation, and nerve damage. Pain behaviour was assessed by von Frey hair algesiometry, and inflammation was evaluated using intravital microscopy to measure leukocyte trafficking in the synovial microvasculature. RESULTS Intra-articular injection of MIA produced mechanical hypersensitivity as measured by von Frey hair algesiometry. Local injection of KML29 (700 μg) reduced joint pain at day 14 post-MIA induction, and this analgesic effect was blocked by the cannabinoid receptor antagonists AM281 and AM630 (P < 0.0001; n = 6). During the acute inflammatory phase of the MIA model (day 1), a significant reduction in withdrawal threshold (P < 0.0001; n = 6-8) and leukocyte trafficking was seen after treatment with KML29 + CXB (P < 0.0001; n = 6-8). Early treatment of MIA-injected knees (days 1-3) with KML29 + CXB ameliorated the development of mechanical secondary allodynia (P < 0.0001; n = 8) in the later stages of the MIA model. CONCLUSIONS Combination therapy of KML29 plus CXB reduced joint pain and inflammation. Thus, dual inhibition of MAGL and cyclooxygenase-2 pathways could be a useful approach to alleviate joint inflammation and pain in OA joints.
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Affiliation(s)
- Holly T Philpott
- Departments of Pharmacology and Anaesthesia, Pain Management & Perioperative Medicine, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Jason J McDougall
- Departments of Pharmacology and Anaesthesia, Pain Management & Perioperative Medicine, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, B3H 4R2, Canada.
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15
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Cannabinoids and the expanded endocannabinoid system in neurological disorders. Nat Rev Neurol 2019; 16:9-29. [DOI: 10.1038/s41582-019-0284-z] [Citation(s) in RCA: 320] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2019] [Indexed: 12/13/2022]
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16
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de Oliveira HU, Dos Santos RS, Malta IHS, Pinho JP, Almeida AFS, Sorgi CA, Peti APF, Xavier GS, Reis LMD, Faccioli LH, Cruz JDS, Ferreira E, Galdino G. Investigation of the Involvement of the Endocannabinoid System in TENS-Induced Antinociception. THE JOURNAL OF PAIN 2019; 21:820-835. [PMID: 31785404 DOI: 10.1016/j.jpain.2019.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/16/2019] [Accepted: 11/11/2019] [Indexed: 01/14/2023]
Abstract
Transcutaneous electrical nerve stimulation (TENS) promotes antinociception by activating the descending pain modulation pathway and consequently releasing endogenous analgesic substances. In addition, recent studies have shown that the endocannabinoid system controls pain. Thus, the present study investigated the involvement of the endocannabinoid system in TENS-induced antinociception of cancer pain using a cancer pain model induced by intraplantar (i.pl.) injections of Ehrlich tumor cells in male Swiss mice. Low- and high-frequency TENS was applied for 20 minutes to the mice's paws, and to investigate the involvement of the endocannabinoid system were used the N-(peperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pitazole-3-carboixamide (AM251), a cannabinoid CB1 receptor antagonist and (5Z,8Z,11Z,14Z)-5,8,11,14-eicosatetraenyl-methylester phosphonofluoridic acid (MAFP), an inhibitor of the endocannabinoid metabolizing enzyme fatty acid amide hydrolase, injected by via i.pl., intrathecal (i.t.), and intradorsolateral periaqueductal gray matter (i.dl.PAG). Furthermore, liquid chromatography-tandem mass spectrometry, western blot, and immunofluorescence assays were used to evaluate the endocannabinoid anandamide levels, cannabinoid CB1 receptor protein levels, and cannabinoid CB1 receptor immunoreactivity, respectively. Low- and high-frequency TENS reduced the mechanical allodynia induced by Ehrlich tumor cells and this effect was reversed by AM251 and potentiated by MAFP at the peripheral and central levels. In addition, TENS increased the endocannabinoid anandamide levels and the cannabinoid CB1 receptor protein levels and immunoreactivity in the paw, spinal cord, and dorsolateral periaqueductal gray matter. These results suggest that low- and high-frequency TENS is effective in controlling cancer pain, and the endocannabinoid system is involved in this effect at both the peripheral and central levels. PERSPECTIVE: TENS is a nonpharmacological strategy that may be used to control cancer pain. Identification of a new mechanism involved in its analgesic effect could lead to the development of clinical studies as well as an increase in its application, lessening the need for pharmacological treatments.
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Affiliation(s)
| | | | | | - José Phellipe Pinho
- Department of Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Carlos Arterio Sorgi
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, Universidade de São Paulo, São Paulo Brazil
| | - Ana Paula Ferranti Peti
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, Universidade de São Paulo, São Paulo Brazil
| | | | | | - Lúcia Helena Faccioli
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, Universidade de São Paulo, São Paulo Brazil
| | - Jader Dos Santos Cruz
- Department of Physiology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Enio Ferreira
- Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Giovane Galdino
- Sciences of Motricity Institute, Federal University of Alfenas, Alfenas, Brazil.
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17
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Attenuation of glutamatergic and nitrergic system contributes to the antidepressant-like effect induced by capsazepine in the forced swimming test. Behav Pharmacol 2019; 30:59-66. [PMID: 30299277 DOI: 10.1097/fbp.0000000000000416] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The transient receptor potential vanilloid 1 (TRPV1) can modulate stress-related behaviours, thus representing an interesting target for new antidepressant drugs. TRPV1 can trigger glutamate release and nitric oxide synthesis in the brain, mechanisms also involved in the neurobiology of depression. However, it is not known if these mechanisms are involved in TRPV1-induced behavioural effects. Therefore, the aim of this study was to verify if the antidepressant-like effect induced by a TRPV1 antagonist in mice submitted to the forced swimming test (FST) would be facilitated by combined treatment with neuronal nitric oxide synthase (nNOS) inhibition and N-methyl-D-aspartate (NMDA) blockade. Male Swiss mice were given (intracerebroventricular) injections of capsazepine (CPZ) (TRPV1 antagonist - 0.05/0.1/0.3/0.6 nmol/µl), and AP7 (NMDA antagonist - 1/3/10 nmol/µl) or N-propyl-L-arginine (NPA, nNOS inhibitor - 0.001/0.01/0.1 nmol/µl), and 10 min later, submitted to an open field test, and immediately afterwards, to the FST. An additional group received coadministration of CPZ and AP7 or CPZ and NPA, in subeffective doses. The results demonstrated that CPZ (0.1 nmol/µl), AP7 (3 nmol/µl) and NPA (0.01/0.1 nmol/µl) induced antidepressant-like effects. Moreover, coadministration of subeffective doses of CPZ and AP7 or CPZ and NPA induced significant antidepressant-like effects. Altogether, the data indicate that blockade of TRPV1 receptors by CPZ induces antidepressant-like effects and that both nNOS inhibition and NMDA blockade facilitate CPZ effects in the FST.
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Russo S, De Azevedo WF. Advances in the Understanding of the Cannabinoid Receptor 1 – Focusing on the Inverse Agonists Interactions. Curr Med Chem 2019; 26:1908-1919. [DOI: 10.2174/0929867325666180417165247] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/21/2018] [Accepted: 04/03/2018] [Indexed: 12/31/2022]
Abstract
Background:
Cannabinoid Receptor 1 (CB1) is a membrane protein prevalent in
the central nervous system, whose crystallographic structure has recently been solved. Studies
will be needed to investigate CB1 complexes with its ligands and its role in the development
of new drugs.
Objective:
Our goal here is to review the studies on CB1, starting with general aspects and
focusing on the recent structural studies, with emphasis on the inverse agonists bound structures.
Methods:
We start with a literature review, and then we describe recent studies on CB 1 crystallographic
structure and docking simulations. We use this structural information to depict
protein-ligand interactions. We also describe the molecular docking method to obtain complex
structures of CB 1 with inverse agonists.
Results:
Analysis of the crystallographic structure and docking results revealed the residues
responsible for the specificity of the inverse agonists for CB 1. Most of the intermolecular interactions
involve hydrophobic residues, with the participation of the residues Phe 170 and
Leu 359 in all complex structures investigated in the present study. For the complexes with
otenabant and taranabant, we observed intermolecular hydrogen bonds involving residues His
178 (otenabant) and Thr 197 and Ser 383 (taranabant).
Conclusion:
Analysis of the structures involving inverse agonists and CB 1 revealed the pivotal
role played by residues Phe 170 and Leu 359 in their interactions and the strong intermolecular
hydrogen bonds highlighting the importance of the exploration of intermolecular interactions
in the development of novel inverse agonists.
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Affiliation(s)
- Silvana Russo
- Laboratory of Computational Systems Biology, School of Sciences, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6681, Porto Alegre-RS 90619-900, Brazil
| | - Walter Filgueira De Azevedo
- Laboratory of Computational Systems Biology, School of Sciences, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6681, Porto Alegre-RS 90619-900, Brazil
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19
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Lisboa SF, Vila-Verde C, Rosa J, Uliana DL, Stern CAJ, Bertoglio LJ, Resstel LB, Guimaraes FS. Tempering aversive/traumatic memories with cannabinoids: a review of evidence from animal and human studies. Psychopharmacology (Berl) 2019; 236:201-226. [PMID: 30604182 DOI: 10.1007/s00213-018-5127-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 11/14/2018] [Indexed: 01/08/2023]
Abstract
RATIONALE Aversive learning and memory are essential to cope with dangerous and stressful stimuli present in an ever-changing environment. When this process is dysfunctional, however, it is associated with posttraumatic stress disorder (PTSD). The endocannabinoid (eCB) system has been implicated in synaptic plasticity associated with physiological and pathological aversive learning and memory. OBJECTIVE AND METHODS The objective of this study was to review and discuss evidence on how and where in the brain genetic or pharmacological interventions targeting the eCB system would attenuate aversive/traumatic memories through extinction facilitation in laboratory animals and humans. The effect size of the experimental intervention under investigation was also calculated. RESULTS Currently available data indicate that direct or indirect activation of cannabinoid type-1 (CB1) receptor facilitates the extinction of aversive/traumatic memories. Activating CB1 receptors around the formation of aversive/traumatic memories or their reminders can potentiate their subsequent extinction. In most cases, the effect size has been large (Cohen's d ≥ 1.0). The brain areas responsible for the abovementioned effects include the medial prefrontal cortex, amygdala, and/or hippocampus. The potential role of cannabinoid type-2 (CB2) receptors in extinction learning is now under investigation. CONCLUSION Drugs augmenting the brain eCB activity can temper the impact of aversive/traumatic experiences by diverse mechanisms depending on the moment of their administration. Considering the pivotal role the extinction process plays in PTSD, the therapeutic potential of these drugs is evident. The sparse number of clinical trials testing these compounds in stress-related disorders is a gap in the literature that needs to be addressed.
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Affiliation(s)
- Sabrina F Lisboa
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil. .,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
| | - C Vila-Verde
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - J Rosa
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - D L Uliana
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - C A J Stern
- Department of Pharmacology, Federal University of Parana, Curitiba, PR, Brazil
| | - L J Bertoglio
- Department of Pharmacology, Federal University of Santa Catarina, Florianopolis, SC, Brazil
| | - L B Resstel
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - F S Guimaraes
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo (FMRP/USP), Av Bandeirantes 3900, Monte Alegre, 14049900, Ribeirão Preto, São Paulo, Brazil.,Center for Interdisciplinary Research on Applied Neurosciences (NAPNA), Medical School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
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20
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Di Marzo V. New approaches and challenges to targeting the endocannabinoid system. Nat Rev Drug Discov 2018; 17:623-639. [DOI: 10.1038/nrd.2018.115] [Citation(s) in RCA: 256] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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21
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Zhang J, Liu K, Elmadhoun O, Ji X, Duan Y, Shi J, He X, Liu X, Wu D, Che R, Geng X, Ding Y. Synergistically Induced Hypothermia and Enhanced Neuroprotection by Pharmacological and Physical Approaches in Stroke. Aging Dis 2018; 9:578-589. [PMID: 30090648 PMCID: PMC6065296 DOI: 10.14336/ad.2017.0817] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 08/17/2017] [Indexed: 12/22/2022] Open
Abstract
Hypothermia is considered as a promising neuroprotective treatment for ischemic stroke but with many limitations. To expand its clinical relevance, this study evaluated the combination of physical (ice pad) and pharmacological [transient receptor potential vanilloid channel 1 (TRPV1) receptor agonist, dihydrocapsaicin (DHC)] approaches for faster cooling and stronger neuroprotection. A total of 144 male Sprague Dawley rats were randomized to 7 groups: sham (n=16), stroke only (n=24), stroke with physical hypothermia at 31ºC for 3 h after the onset of reperfusion (n=24), high-dose DHC (H-DHC)(1.5 mg/kg, n=24), low-dose DHC (L-DHC)(0.5 mg/kg, n=32) with (n=8) or without (n=24) external body temperature control at ~38 ºC (L-DHC, 38 ºC), and combination therapy (L-DHC+ ice pad, n=24). Rats were subjected to middle cerebral artery occlusion (MCAO) for 2 h. Infarct volume, neurological deficits and apoptotic cell death were determined at 24 h after reperfusion. Expression of pro- and anti-apoptotic proteins was evaluated by Western blot. ATP and reactive oxygen species (ROS) were detected by biochemical assays at 6 and 24 h after reperfusion. Combination therapy of L-DHC and ice pad significantly improved every measured outcome compared to monotherapies. Combination therapy achieved hypothermia faster by 28.6% than ice pad, 350% than L-DHC and 200% than H-DHC alone. Combination therapy reduced (p<0.05) neurological deficits by 63% vs. 26% with L-DHC. No effect was observed when using ice pad or H-DHC alone. L-DHC and ice pad combination improved brain oxidative metabolism by reducing (p<0.05) ROS at 6 and 24 h after reperfusion and increasing ATP levels by 42.9% compared to 25% elevation with L-DHC alone. Finally, combination therapy decreased apoptotic cell death by 48.5% vs. 24.9% with L-DHC, associated with increased anti-apoptotic protein and reduced pro-apoptotic protein levels (p<0.001). Our study has demonstrated that combining physical and pharmacological hypothermia is a promising therapeutic approach in ischemic stroke, and warrants further translational investigations.
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Affiliation(s)
- Jun Zhang
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Kaiyin Liu
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Omar Elmadhoun
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Xunming Ji
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yunxia Duan
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Jingfei Shi
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiaoduo He
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiangrong Liu
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Di Wu
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ruiwen Che
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiaokun Geng
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI 48201, USA
- China-America Institute of Neuroscience, Luhe Hospital, Capital Medical University, Beijing, China
| | - Yuchuan Ding
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI 48201, USA
- China-America Institute of Neuroscience, Luhe Hospital, Capital Medical University, Beijing, China
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22
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Back FP, Carobrez AP. Periaqueductal gray glutamatergic, cannabinoid and vanilloid receptor interplay in defensive behavior and aversive memory formation. Neuropharmacology 2018; 135:399-411. [DOI: 10.1016/j.neuropharm.2018.03.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 03/07/2018] [Accepted: 03/23/2018] [Indexed: 11/29/2022]
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Patel S, Hill MN, Cheer JF, Wotjak CT, Holmes A. The endocannabinoid system as a target for novel anxiolytic drugs. Neurosci Biobehav Rev 2017; 76:56-66. [PMID: 28434588 PMCID: PMC5407316 DOI: 10.1016/j.neubiorev.2016.12.033] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/22/2016] [Accepted: 12/16/2016] [Indexed: 12/01/2022]
Abstract
The endocannabinoid (eCB) system has attracted attention for its role in various behavioral and brain functions, and as a therapeutic target in neuropsychiatric disease states, including anxiety disorders and other conditions resulting from dysfunctional responses to stress. In this mini-review, we highlight components of the eCB system that offer potential 'druggable' targets for new anxiolytic medications, emphasizing some of the less well-discussed options. We discuss how selectively amplifying eCBs recruitment by interfering with eCB-degradation, via fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), has been linked to reductions in anxiety-like behaviors in rodents and variation in human anxiety symptoms. We also discuss a non-canonical route to regulate eCB degradation that involves interfering with cyclooxygenase-2 (COX-2). Next, we discuss approaches to targeting eCB receptor-signaling in ways that do not involve the cannabinoid receptor subtype 1 (CB1R); by targeting the CB2R subtype and the transient receptor potential vanilloid type 1 (TRPV1). Finally, we review evidence that cannabidiol (CBD), while representing a less specific pharmacological approach, may be another way to modulate eCBs and interacting neurotransmitter systems to alleviate anxiety. Taken together, these various approaches provide a range of plausible paths to developing novel compounds that could prove useful for treating trauma-related and anxiety disorders.
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Affiliation(s)
- Sachin Patel
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, USA; Vanderbilt Kennedy Center for Human Development, Vanderbilt University Medical Center, Nashville, USA
| | - Mathew N Hill
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB, Canada; Departments of Cell Biology and Anatomy and Psychiatry, University of Calgary, Calgary, AB, Canada
| | - Joseph F Cheer
- Department of Anatomy and Neurobiology and Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Carsten T Wotjak
- Max Planck Institute of Psychiatry, Department of Stress Neurobiology & Neurogenetics, Munich, Germany
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.
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24
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The endocannabinoid system, a novel and key participant in acupuncture's multiple beneficial effects. Neurosci Biobehav Rev 2017; 77:340-357. [PMID: 28412017 DOI: 10.1016/j.neubiorev.2017.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 03/31/2017] [Accepted: 04/06/2017] [Indexed: 12/22/2022]
Abstract
Acupuncture and its modified forms have been used to treat multiple medical conditions, but whether the diverse effects of acupuncture are intrinsically linked at the cellular and molecular level and how they might be connected have yet to be determined. Recently, an emerging role for the endocannabinoid system (ECS) in the regulation of a variety of physiological/pathological conditions has been identified. Overlap between the biological and therapeutic effects induced by ECS activation and acupuncture has facilitated investigations into the participation of ECS in the acupuncture-induced beneficial effects, which have shed light on the idea that the ECS may be a primary mediator and regulatory factor of acupuncture's beneficial effects. This review seeks to provide a comprehensive summary of the existing literature concerning the role of endocannabinoid signaling in the various effects of acupuncture, and suggests a novel notion that acupuncture may restore homeostasis under different pathological conditions by regulating similar networks of signaling pathways, resulting in the activation of different reaction cascades in specific tissues in response to pathological insults.
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Zinn S, Sisignano M, Kern K, Pierre S, Tunaru S, Jordan H, Suo J, Treutlein EM, Angioni C, Ferreiros N, Leffler A, DeBruin N, Offermanns S, Geisslinger G, Scholich K. The leukotriene B4 receptors BLT1 and BLT2 form an antagonistic sensitizing system in peripheral sensory neurons. J Biol Chem 2017; 292:6123-6134. [PMID: 28242764 DOI: 10.1074/jbc.m116.769125] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/09/2017] [Indexed: 11/06/2022] Open
Abstract
Sensitization of the heat-activated ion channel transient receptor potential vanilloid 1 (TRPV1) through lipids is a fundamental mechanism during inflammation-induced peripheral sensitization. Leukotriene B4 is a proinflammatory lipid mediator whose role in peripheral nociceptive sensitization is not well understood to date. Two major G-protein-coupled receptors for leukotriene B4 have been identified: the high-affinity receptor BLT1 and the low-affinity receptor BLT2. Transcriptional screening for the expression G-protein-coupled receptors in murine dorsal root ganglia showed that both receptors were among the highest expressed in dorsal root ganglia. Calcium imaging revealed a sensitization of TRPV1-mediated calcium increases in a relative narrow concentration range for leukotriene B4 (100-200 nm). Selective antagonists and neurons from knock-out mice demonstrated a BLT1-dependent sensitization of TRPV1-mediated calcium increases. Accordingly, leukotriene B4-induced thermal hyperalgesia was mediated through BLT1 and TRPV1 as shown using the respective knock-out mice. Importantly, higher leukotriene B4 concentrations (>0.5 μm) and BLT2 agonists abolished sensitization of the TRPV1-mediated calcium increases. Also, BLT2 activation inhibited protein kinase C- and protein kinase A-mediated sensitization processes through the phosphatase calcineurin. Consequently, a selective BLT2-receptor agonist increased thermal and mechanical withdrawal thresholds during zymosan-induced inflammation. In accordance with these data, immunohistochemical analysis showed that both leukotriene B4 receptors were expressed in peripheral sensory neurons. Thus, the data show that the two leukotriene B4 receptors have opposing roles in the sensitization of peripheral sensory neurons forming a self-restricting system.
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Affiliation(s)
- Sebastian Zinn
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany
| | - Marco Sisignano
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany
| | - Katharina Kern
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany
| | - Sandra Pierre
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany
| | - Sorin Tunaru
- the Department of Pharmacology, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Holger Jordan
- the Fraunhofer Institute of Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, 60590 Frankfurt, Germany, and
| | - Jing Suo
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany
| | - Elsa-Marie Treutlein
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany
| | - Carlo Angioni
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany
| | - Nerea Ferreiros
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany
| | - Andreas Leffler
- the Department for Anaesthesiology and Critical Care Medicine, Hannover Medical School, 30625 Hannover, Germany
| | - Natasja DeBruin
- the Fraunhofer Institute of Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, 60590 Frankfurt, Germany, and
| | - Stefan Offermanns
- the Department of Pharmacology, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Gerd Geisslinger
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany.,the Fraunhofer Institute of Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, 60590 Frankfurt, Germany, and
| | - Klaus Scholich
- From the Institut für Klinische Pharmakologie, Pharmazentrum Frankfurt, Klinikum der Goethe-Universität Frankfurt, 60590 Frankfurt, Germany,
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Carletti F, Gambino G, Rizzo V, Ferraro G, Sardo P. Involvement of TRPV1 channels in the activity of the cannabinoid WIN 55,212-2 in an acute rat model of temporal lobe epilepsy. Epilepsy Res 2016; 122:56-65. [PMID: 26970948 DOI: 10.1016/j.eplepsyres.2016.02.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/18/2016] [Accepted: 02/09/2016] [Indexed: 10/21/2022]
Abstract
The exogenous cannabinoid agonist WIN 55,212-2, (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo[1,2,3-de]-1,4-benzoxazin-6-Yl]-1-naphthalenylmethanone (WIN), has revealed to play a role on modulating the hyperexcitability phenomena in the hippocampus. Cannabinoid-mediated mechanisms of neuroprotection have recently been found to imply the modulation of transient receptor potential vanilloid 1 (TRPV1), a cationic channel subfamily that regulate synaptic excitation. In our study, we assessed the influence of pharmacological manipulation of TRPV1 function, alone and on WIN antiepileptic activity, in the Maximal Dentate Activation (MDA) acute model of temporal lobe epilepsy. Our results showed that the TRPV1 agonist, capsaicin, increased epileptic outcomes; whilst antagonizing TRPV1 with capsazepine exerts a protective role on paroxysmal discharge. When capsaicin is co-administered with WIN effective dose of 10mg/kg is able to reduce its antiepileptic strength, especially on the triggering of MDA response. Accordingly, capsazepine at the protective dose of 2mg/kg managed to potentiate WIN antiepileptic effects, when co-treated. Moreover, WIN subeffective dose of 5mg/kg was turned into effective when capsazepine comes into play. This evidence suggests that systemic administration of TRPV1-active drugs influences electrically induced epilepsy, with a noticeable protective activity for capsazepine. Furthermore, results from the pharmacological interaction with WIN support an interplay between cannabinoid and TRPV1 signaling that could represent a promising approach for a future pharmacological strategy to challenge hyperexcitability-based diseases.
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Affiliation(s)
- Fabio Carletti
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
| | - Giuditta Gambino
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
| | - Valerio Rizzo
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
| | - Giuseppe Ferraro
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
| | - Pierangelo Sardo
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
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Aubrey KR, Drew GM, Jeong HJ, Lau BK, Vaughan CW. Endocannabinoids control vesicle release mode at midbrain periaqueductal grey inhibitory synapses. J Physiol 2016; 595:165-178. [PMID: 27461371 DOI: 10.1113/jp272292] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 07/15/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The midbrain periaqueductal grey (PAG) forms part of an endogenous analgesic system which is tightly regulated by the neurotransmitter GABA. The role of endocannabinoids in regulating GABAergic control of this system was examined in rat PAG slices. Under basal conditions GABAergic neurotransmission onto PAG output neurons was multivesicular. Activation of the endocannabinoid system reduced GABAergic inhibition by reducing the probability of release and by shifting release to a univesicular mode. Blockade of endocannabinoid system unmasked a tonic control over the probability and mode of GABA release. These findings provides a mechanistic foundation for the control of the PAG analgesic system by disinhibition. ABSTRACT The midbrain periaqueductal grey (PAG) has a crucial role in coordinating endogenous analgesic responses to physiological and psychological stressors. Endocannabinoids are thought to mediate a form of stress-induced analgesia within the PAG by relieving GABAergic inhibition of output neurons, a process known as disinhibition. This disinhibition is thought to be achieved by a presynaptic reduction in GABA release probability. We examined whether other mechanisms have a role in endocannabinoid modulation of GABAergic synaptic transmission within the rat PAG. The group I mGluR agonist DHPG ((R,S)-3,5-dihydroxyphenylglycine) inhibited evoked IPSCs and increased their paired pulse ratio in normal external Ca2+ , and when release probability was reduced by lowering Ca2+ . However, the effect of DHPG on the coefficient of variation and kinetics of evoked IPSCs differed between normal and low Ca2+ . Lowering external Ca2+ had a similar effect on evoked IPSCs to that observed for DHPG in normal external Ca2+ . The low affinity GABAA receptor antagonist TPMPA ((1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid) inhibited evoked IPSCs to a greater extent in low than in normal Ca2+ . Together these findings indicate that the normal mode of GABA release is multivesicular within the PAG, and that DHPG and lowering external Ca2+ switch this to a univesicular mode. The effects of DHPG were mediated by mGlu5 receptor engagement of the retrograde endocannabinoid system. Blockade of endocannabinoid breakdown produced a similar shift in the mode of release. We conclude that endocannabinoids control both the mode and the probability of GABA release within the PAG.
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Affiliation(s)
- Karin R Aubrey
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, The University of Sydney and Royal North Shore Hospital, St. Leonards, New South Wales, Australia
| | - Geoffrey M Drew
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, The University of Sydney and Royal North Shore Hospital, St. Leonards, New South Wales, Australia
| | - Hyo-Jin Jeong
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, The University of Sydney and Royal North Shore Hospital, St. Leonards, New South Wales, Australia
| | - Benjamin K Lau
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, The University of Sydney and Royal North Shore Hospital, St. Leonards, New South Wales, Australia
| | - Christopher W Vaughan
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, The University of Sydney and Royal North Shore Hospital, St. Leonards, New South Wales, Australia
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Olmo IG, Ferreira-Vieira TH, Ribeiro FM. Dissecting the Signaling Pathways Involved in the Crosstalk between Metabotropic Glutamate 5 and Cannabinoid Type 1 Receptors. Mol Pharmacol 2016; 90:609-619. [PMID: 27338080 DOI: 10.1124/mol.116.104372] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/16/2016] [Indexed: 02/06/2023] Open
Abstract
The metabotropic glutamate 5 receptor and the cannabinoid type 1 receptor are G protein-coupled receptors that are widely expressed in the central nervous system. Metabotropic glutamate 5 receptors, present at the postsynaptic site, are coupled to Gαq/11 proteins and display an excitatory response upon activation, whereas the cannabinoid type 1 receptor, mainly present at presynaptic terminals, is coupled to the Gi/o protein and triggers an inhibitory response. Recent studies suggest that the glutamatergic and endocannabinoid systems exhibit a functional interaction to modulate several neural processes. In this review, we discuss possible mechanisms involved in this crosstalk and its relationship with physiologic and pathologic conditions, including nociception, addiction, and fragile X syndrome.
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Affiliation(s)
- Isabella G Olmo
- Department of Biochemistry and Immunology, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Talita H Ferreira-Vieira
- Department of Biochemistry and Immunology, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Fabiola M Ribeiro
- Department of Biochemistry and Immunology, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Todd SM, Arnold JC. Neural correlates of interactions between cannabidiol and Δ(9) -tetrahydrocannabinol in mice: implications for medical cannabis. Br J Pharmacol 2015; 173:53-65. [PMID: 26377899 DOI: 10.1111/bph.13333] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 09/01/2015] [Accepted: 09/06/2015] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE It has been proposed that medicinal strains of cannabis and therapeutic preparations would be safer with a more balanced concentration ratio of Δ(9) -tetrahydrocannabinol (THC) to cannabidiol (CBD), as CBD reduces the adverse psychotropic effects of THC. However, our understanding of CBD and THC interactions is limited and the brain circuitry mediating interactions between CBD and THC are unknown. The aim of this study was to investigate whether CBD modulated the functional effects and c-Fos expression induced by THC, using a 1:1 dose ratio that approximates therapeutic strains of cannabis and nabiximols. EXPERIMENTAL APPROACH Male C57BL/6 mice were treated with vehicle, CBD, THC or a combination of CBD and THC (10 mg·kg(-1) i.p. for both cannabinoids) to examine effects on locomotor activity, anxiety-related behaviour, body temperature and brain c-Fos expression (a marker of neuronal activation). KEY RESULTS CBD potentiated THC-induced locomotor suppression but reduced the hypothermic and anxiogenic effects of THC. CBD alone had no effect on these measures. THC increased brain activation as measured by c-Fos expression in 11 of the 35 brain regions studied. CBD co-administration suppressed THC-induced c-Fos expression in six of these brain regions. This effect was most pronounced in the medial preoptic nucleus and lateral periaqueductal gray. Treatment with CBD alone diminished c-Fos expression only in the central nucleus of the amygdala compared with vehicle. CONCLUSIONS AND IMPLICATIONS These data confirm that CBD modulated the pharmacological actions of THC and provide new information regarding brain regions involved in the interaction between CBD and THC.
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Affiliation(s)
- S M Todd
- Brain and Mind Centre, University of Sydney, Sydney, Australia.,Discipline of Pharmacology, School of Medical Science, University of Sydney, Sydney, Australia
| | - J C Arnold
- Brain and Mind Centre, University of Sydney, Sydney, Australia.,Discipline of Pharmacology, School of Medical Science, University of Sydney, Sydney, Australia
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Miyanohara J, Shirakawa H, Sanpei K, Nakagawa T, Kaneko S. A pathophysiological role of TRPV1 in ischemic injury after transient focal cerebral ischemia in mice. Biochem Biophys Res Commun 2015; 467:478-83. [DOI: 10.1016/j.bbrc.2015.10.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/05/2015] [Indexed: 12/21/2022]
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Viana TG, Hott SC, Resstel LB, Aguiar DC, Moreira FA. Anti-aversive role of the endocannabinoid system in the periaqueductal gray stimulation model of panic attacks in rats. Psychopharmacology (Berl) 2015; 232:1545-53. [PMID: 25388290 DOI: 10.1007/s00213-014-3793-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 10/21/2014] [Indexed: 12/28/2022]
Abstract
RATIONALE Direct activation of the cannabinoid CB1 receptor in the dorsolateral periaqueductal gray (dlPAG) inhibits anxiety- and panic-related behaviours in experimental animals. It has remained unclear, however, whether the local endocannabinoid signalling is recruited as a protective mechanism against aversive stimuli. OBJECTIVES The present study tested the hypothesis that the endocannabinoid system counteracts aversive responses in the dlPAG-stimulation model of panic attacks. METHODS All drugs were infused into the dlPAG of rats. Local chemical stimulation with N-methyl-D-aspartate (NMDA, 1 nmol) was employed to induce panic-like behavioural and cardiovascular responses in freely moving and anaesthetized animals, respectively. The neuronal activity in the dlPAG was investigated by c-Fos immunohistochemistry. RESULTS The selective CB1 receptor agonist, ACEA (0.005-0.5 pmol), prevented the NMDA-induced panic-like escape responses. More interestingly, increasing the local levels of endogenous anandamide with a fatty acid amide hydrolase (FAAH) inhibitor, URB597 (0.3-3 nmol), prevented both the behavioural response and the increase in blood pressure induced by NMDA. The effect of URB597 (3 nmol) was reversed by the CB1 receptor antagonist, AM251 (0.1 nmol). Moreover, an otherwise ineffective and sub-threshold dose of NMDA (0.5 nmol) was able to induce a panic-like response if local CB1 receptors were previously blocked by AM251 (0.1 nmol). Finally, URB597 prevented the NMDA-induced neuronal activation of the dlPAG. CONCLUSIONS The endocannabinoid system in the dlPAG attenuates the behavioural, cellular and cardiovascular consequences of aversive stimuli. This process may be considered for the development of additional treatments against panic and other anxiety-related disorders.
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Affiliation(s)
- Thércia G Viana
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil
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Vázquez C, Tolón RM, Pazos MR, Moreno M, Koester EC, Cravatt BF, Hillard CJ, Romero J. Endocannabinoids regulate the activity of astrocytic hemichannels and the microglial response against an injury: In vivo studies. Neurobiol Dis 2015; 79:41-50. [PMID: 25917763 DOI: 10.1016/j.nbd.2015.04.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 04/02/2015] [Accepted: 04/19/2015] [Indexed: 10/23/2022] Open
Abstract
Anandamide (AEA) is an endocannabinoid (EC) that modulates multiple functions in the CNS and that is released in areas of injury, exerting putative neuroprotective actions. In the present study, we have used intravital microscopy to analyze the role of the EC system in the glial response against an acute insult. Our data show that AEA modulates astroglial function in vivo by increasing connexin-43 hemichannel (HC) activity. Furthermore, the genetic inactivation of the AEA-degrading enzyme, fatty acid amide hydrolase (FAAH), also increased HC activity and enhanced the microglial response against an acute injury to the brain parenchyma, effects that were mediated by cannabinoid CB1 receptors. The contribution of ATP released through an astrocytic HC was critical for the microglial response, as this was prevented by the use of the HC blocker flufenamic acid and by apyrase. As could be expected, brain concentrations of AEA, palmitoylethanolamide (PEA) and oleoylethanolamide (OEA) were elevated in FAAH-null mice, while 2-arachidonoylglycerol (2-AG) concentrations remained unaltered. In summary, these findings demonstrate that AEA modifies glial functions by promoting an enhanced pro-inflammatory glial response in the brain.
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Affiliation(s)
- Carmen Vázquez
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, 28922 Alcorcón, Madrid, Spain
| | - Rosa María Tolón
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, 28922 Alcorcón, Madrid, Spain
| | - María Ruth Pazos
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, 28922 Alcorcón, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
| | - Marta Moreno
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, 28922 Alcorcón, Madrid, Spain
| | - Erin C Koester
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Benjamin F Cravatt
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Cecilia J Hillard
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Julián Romero
- Laboratorio de Apoyo a la Investigación, Hospital Universitario Fundación Alcorcón, 28922 Alcorcón, Madrid, Spain; School of Biosciences, Universidad Francisco de Vitoria, Pozuelo de Alarcón, 28223 Madrid, Spain.
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Lau BK, Vaughan CW. Descending modulation of pain: the GABA disinhibition hypothesis of analgesia. Curr Opin Neurobiol 2014; 29:159-64. [DOI: 10.1016/j.conb.2014.07.010] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/20/2014] [Accepted: 07/02/2014] [Indexed: 10/25/2022]
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Aguiar D, Moreira F, Terzian A, Fogaça M, Lisboa S, Wotjak C, Guimaraes F. Modulation of defensive behavior by Transient Receptor Potential Vanilloid Type-1 (TRPV1) Channels. Neurosci Biobehav Rev 2014; 46 Pt 3:418-28. [DOI: 10.1016/j.neubiorev.2014.03.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 02/04/2014] [Accepted: 03/18/2014] [Indexed: 12/20/2022]
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Hu SSJ, Ho YC, Chiou LC. No more pain upon Gq-protein-coupled receptor activation: role of endocannabinoids. Eur J Neurosci 2014; 39:467-84. [PMID: 24494686 DOI: 10.1111/ejn.12475] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 12/02/2013] [Accepted: 12/05/2013] [Indexed: 01/24/2023]
Abstract
Marijuana has been used to relieve pain for centuries. The analgesic mechanism of its constituents, the cannabinoids, was only revealed after the discovery of cannabinoid receptors (CB1 and CB2) two decades ago. The subsequent identification of the endocannabinoids, anandamide and 2-arachidonoylglycerol (2-AG), and their biosynthetic and degradation enzymes discloses the therapeutic potential of compounds targeting the endocannabinoid system for pain control. Inhibitors of the anandamide and 2-AG degradation enzymes, fatty acid amide hydrolase and monoacylglycerol lipase, respectively, may be superior to direct cannabinoid receptor ligands as endocannabinoids are synthesized on demand and rapidly degraded, focusing action at generating sites. Recently, a promising strategy for pain relief was revealed in the periaqueductal gray (PAG). It is initiated by Gq-protein-coupled receptor (Gq PCR) activation of the phospholipase C-diacylglycerol lipase enzymatic cascade, generating 2-AG that produces inhibition of GABAergic transmission (disinhibition) in the PAG, thereby leading to analgesia. Here, we introduce the antinociceptive properties of exogenous cannabinoids and endocannabinoids, involving their biosynthesis and degradation processes, particularly in the PAG. We also review recent studies disclosing the Gq PCR-phospholipase C-diacylglycerol lipase-2-AG retrograde disinhibition mechanism in the PAG, induced by activating several Gq PCRs, including metabotropic glutamatergic (type 5 metabotropic glutamate receptor), muscarinic acetylcholine (M1/M3), and orexin 1 receptors. Disinhibition mediated by type 5 metabotropic glutamate receptor can be initiated by glutamate transporter inhibitors or indirectly by substance P, neurotensin, cholecystokinin and capsaicin. Finally, the putative role of 2-AG generated after activating the above neurotransmitter receptors in stress-induced analgesia is discussed.
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Affiliation(s)
- Sherry Shu-Jung Hu
- Department of Psychology, National Cheng Kung University, Tainan, Taiwan
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Wilson-Poe AR, Lau BK, Vaughan CW. Repeated morphine treatment alters cannabinoid modulation of GABAergic synaptic transmission within the rat periaqueductal grey. Br J Pharmacol 2014; 172:681-90. [PMID: 24916363 DOI: 10.1111/bph.12809] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 05/29/2014] [Accepted: 06/05/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Cannabinoids and opioids produce antinociception by modulating GABAergic synaptic transmission in a descending analgesic pathway from the midbrain periaqueductal grey (PAG). While chronic opioid treatment produces opioid tolerance, it has recently been shown to enhance cannabinoid-induced antinociception within the PAG. This study examined the effect of repeated opioid treatment on opioid and cannabinoid presynaptic modulation of GABAergic synaptic transmission in PAG. EXPERIMENTAL APPROACH Midbrain PAG slices were prepared from untreated rats, and rats that had undergone repeated morphine or saline pretreatment. Whole-cell voltage-clamp recordings were made from neurons within the ventrolateral PAG. KEY RESULTS In slices from untreated animals, the cannabinoid receptor agonist WIN55212 and the μ receptor agonist DAMGO inhibited electrically evoked GABAA receptor-mediated inhibitory postsynaptic currents (IPSCs) IPSCs in PAG neurons, with IC50 s of 30 and 100 nM respectively. The inhibition of evoked IPSCs produced by WIN55212 (30 nM) and DAMGO (100 nM) was similar in PAG neurons from morphine- and saline-treated animals. The cannabinoid CB1 receptor antagonist AM251 increased the frequency of spontaneous miniature IPSCs in PAG neurons from repeated morphine-, but not saline-treated animals. DAMGO inhibition of evoked IPSCs was enhanced in the presence of AM251 in morphine-, but not saline-treated animals. CONCLUSIONS AND IMPLICATIONS These results indicate that the efficiency of agonist-induced inhibition of GABAergic synaptic transmission is enhanced by morphine treatment, although this is dampened by endocannabinoid-mediated tonic inhibition. Thus, endocannabinoid modulation of synaptic transmission could provide an alternative analgesic approach in a morphine-tolerant state. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.
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Affiliation(s)
- A R Wilson-Poe
- Pain Management Research Institute, Kolling Institute for Medical Research, Northern Clinical School, The University of Sydney, St Leonards, NSW, Australia
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Lau BK, Drew GM, Mitchell VA, Vaughan CW. Endocannabinoid modulation by FAAH and monoacylglycerol lipase within the analgesic circuitry of the periaqueductal grey. Br J Pharmacol 2014; 171:5225-36. [PMID: 25041240 DOI: 10.1111/bph.12839] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 06/19/2014] [Accepted: 06/27/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Endogenous cannabinoids (endocannabinoids) in the periaqueductal grey (PAG) play a vital role in mediating stress-induced analgesia. This analgesic effect of endocannabinoids is enhanced by pharmacological inhibition of their degradative enzymes. However, the specific effects of endocannabinoids and the inhibitors of their degradation are largely unknown within this pain-modulating region. EXPERIMENTAL APPROACH In vitro electrophysiological recordings were conducted from PAG neurons in rat midbrain slices. The effects of the major endocannabinoids and their degradation inhibitors on inhibitory GABAergic synaptic transmission were examined. KEY RESULTS Exogenous application of the endocannabinoid, anandamide (AEA), but not 2-arachidonoylglycerol (2-AG), produced a reduction in inhibitory GABAergic transmission in PAG neurons. This AEA-induced suppression of inhibition was enhanced by the fatty acid amide hydrolase (FAAH) inhibitor, URB597, whereas a 2-AG-induced suppression of inhibition was unmasked by the monoacylglycerol lipase (MGL) inhibitor, JZL184. In addition, application of the CB1 receptor antagonist, AM251, facilitated the basal GABAergic transmission in the presence of URB597 and JZL184, which was further enhanced by the dual FAAH/MGL inhibitor, JZL195. CONCLUSIONS AND IMPLICATIONS Our results indicate that AEA and 2-AG act via disinhibition within the PAG, a cellular action consistent with analgesia. These actions of AEA and 2-AG are tightly regulated by their respective degradative enzymes, FAAH and MGL. Furthermore, individual or combined inhibition of FAAH and/or MGL enhanced tonic disinhibition within the PAG. Therefore, the current findings support the therapeutic potential of FAAH and MGL inhibitors as a novel pharmacotherapy for pain.
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Affiliation(s)
- Benjamin K Lau
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, The University of Sydney at Royal North Shore Hospital, St Leonards, NSW, Australia
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Inhibition of endocannabinoid neuronal uptake and hydrolysis as strategies for developing anxiolytic drugs. Behav Pharmacol 2014; 25:425-33. [DOI: 10.1097/fbp.0000000000000073] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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The dual blocker of FAAH/TRPV1 N-arachidonoylserotonin reverses the behavioral despair induced by stress in rats and modulates the HPA-axis. Pharmacol Res 2014; 87:151-9. [DOI: 10.1016/j.phrs.2014.04.014] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 04/25/2014] [Accepted: 04/27/2014] [Indexed: 02/06/2023]
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Basavarajappa BS, Nagre NN, Xie S, Subbanna S. Elevation of endogenous anandamide impairs LTP, learning, and memory through CB1 receptor signaling in mice. Hippocampus 2014; 24:808-18. [PMID: 24648181 DOI: 10.1002/hipo.22272] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2014] [Indexed: 12/17/2022]
Abstract
In rodents, many exogenous and endogenous cannabinoids, such as anandamide (AEA) and 2-arachidonyl glycerol (2-AG), have been shown to play an important role in certain hippocampal memory processes. However, the mechanisms by which endogenous AEA regulate this processes are not well understood. Here the effects of AEA on long-term potentiation (LTP), hippocampal-dependent learning and memory tasks, pERK1/2, pCaMKIV, and pCREB signaling events in both cannabinoid receptor type 1 (CB1R) wild-type (WT) and knockout (KO) mice were assessed following administration of URB597, an inhibitor of the fatty acid amide hydrolase (FAAH). Acute administration of URB597 enhanced AEA levels without affecting the levels of 2-AG or CB1R in the hippocampus and neocortex as compared to vehicle. In hippocampal slices, URB597 impaired LTP in CB1R WT but not in KO littermates. URB597 impaired object recognition, spontaneous alternation and spatial memory in the Y-maze test in CB1R WT mice but not in KO mice. Furthermore, URB597 enhanced ERK phosphorylation in WT without affecting total ERK levels in WT or KO mice. URB597 impaired CaMKIV and CREB phosphorylation in WT but not in KO mice. CB1R KO mice have a lower pCaMKIV/CaMKIV ratio and higher pCREB/CREB ratio as compared to WT littermates. Our results indicate that pharmacologically elevated AEA impair LTP, learning and memory and inhibit CaMKIV and CREB phosphorylation, via the activation of CB1Rs. Collectively, these findings also suggest that pharmacological elevation of AEA beyond normal concentrations is also detrimental for the underlying physiological responses.
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Affiliation(s)
- Balapal S Basavarajappa
- Division of Analytical Psychopharmacology, Nathan Kline Institute for Psychiatric Research, Orangeburg, New York; New York State Psychiatric Institute, College of Physicians & Surgeons, Columbia University, New York, New York; Department of Psychiatry, College of Physicians & Surgeons, Columbia University, New York, New York
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Medial prefrontal cortex Transient Receptor Potential Vanilloid Type 1 (TRPV1) in the expression of contextual fear conditioning in Wistar rats. Psychopharmacology (Berl) 2014; 231:149-57. [PMID: 23922023 DOI: 10.1007/s00213-013-3211-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 07/17/2013] [Indexed: 10/26/2022]
Abstract
RATIONALE Contextual fear is evoked by re-exposing an animal to an environment that has been previously paired with an aversive or unpleasant stimulus. It can be assessed by freezing and cardiovascular changes such as increase in mean arterial pressure and heart rate. A marked increase in neuronal activity is associated with contextual fear conditioning, especially in limbic structures involved with defense reactions, such as the ventral portion of medial prefrontal cortex. OBJECTIVE Given the fact that transient receptor potential vanilloid type 1 (TRPV1) receptors could be involved in the expression of defensive behavior, the present work tested the hypothesis that TRPV1 manipulation in the ventromedial prefrontal cortex (vMPFC) modulates the expression of contextual conditioned fear. METHODS Male Wistar rats received bilateral microinjections into the vMPFC of the TRPV1 receptor antagonists capsazepine (1, 10, and 60 nmol/200 nL) or 6-iodonordihydrocapsaicin (3 nmol/200 nL), and the TRPV1 agonist capsaicin (1 nmol/200 nL) preceded by vehicle or 6-iodonordihydrocapsaicin before re-exposure to the experimental chamber for 10 min, 48 h after conditioning in two different protocols distinct by their aversiveness. RESULTS Both antagonists reduced the freezing and cardiovascular responses in the high aversive protocol. Capsaicin caused an increase in fear-associated responses that could be blocked by 6-iodonordihydrocapsaicin. CONCLUSIONS Our results indicate that TRPV1 receptors located in the vMPFC have a tonic involvement in the modulation of the expression of contextual fear conditioning.
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Chiou LC, Hu SSJ, Ho YC. Targeting the cannabinoid system for pain relief? ACTA ACUST UNITED AC 2013; 51:161-70. [PMID: 24529672 DOI: 10.1016/j.aat.2013.10.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/11/2013] [Indexed: 12/15/2022]
Abstract
Marijuana has been used to relieve pain for centuries, but its analgesic mechanism has only been understood during the past two decades. It is mainly mediated by its constituents, cannabinoids, through activating central cannabinoid 1 (CB1) receptors, as well as peripheral CB1 and CB2 receptors. CB2-selective agonists have the benefit of lacking CB1 receptor-mediated CNS side effects. Anandamide and 2-arachidonoylglycerol (2-AG) are two intensively studied endogenous lipid ligands of cannabinoid receptors, termed endocannabinoids, which are synthesized on demand and rapidly degraded. Thus, inhibitors of their degradation enzymes, fatty acid amide hydrolase and monoacylglycerol lipase (MAGL), respectively, may be superior to direct cannabinoid receptor ligands as a promising strategy for pain relief. In addition to the antinociceptive properties of exogenous cannabinoids and endocannabinoids, involving their biosynthesis and degradation processes, we also review recent studies that revealed a novel analgesic mechanism, involving 2-AG in the periaqueductal gray (PAG), a midbrain region for initiating descending pain inhibition. It is initiated by Gq-protein-coupled receptor (GqPCR) activation of the phospholipase C (PLC)-diacylglycerol lipase (DAGL) enzymatic cascade, generating 2-AG that produces inhibition of GABAergic transmission (disinhibition) in the PAG, thereby leading to analgesia. This GqPCR-PLC-DAGL-2-AG retrograde disinhibition mechanism in the PAG can be initiated by activating type 5 metabotropic glutamate receptor (mGluR5), muscarinic acetylcholine (M1/M3), and orexin (OX1) receptors. mGluR5-mediated disinhibition can be initiated by glutamate transporter inhibitors, or indirectly by substance P, neurotensin, cholecystokinin, capsaicin, and AM404, the bioactive metabolite of acetaminophen in the brain. The putative role of 2-AG generated after activating the above neurotransmitter receptors in stress-induced analgesia is also discussed.
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Affiliation(s)
- Lih-Chu Chiou
- Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Pharmacology, National Taiwan University, Taipei, Taiwan; Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan; Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan.
| | - Sherry Shu-Jung Hu
- Department of Psychology, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Cheng Ho
- Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
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Role of FAAH-like anandamide transporter in anandamide inactivation. PLoS One 2013; 8:e79355. [PMID: 24223930 PMCID: PMC3817039 DOI: 10.1371/journal.pone.0079355] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/30/2013] [Indexed: 11/19/2022] Open
Abstract
The endocannabinoid system modulates numerous physiological processes including nociception and reproduction. Anandamide (AEA) is an endocannabinoid that is inactivated by cellular uptake followed by intracellular hydrolysis by fatty acid amide hydrolase (FAAH). Recently, FAAH-like anandamide transporter (FLAT), a truncated and catalytically-inactive variant of FAAH, was proposed to function as an intracellular AEA carrier and mediate its delivery to FAAH for hydrolysis. Pharmacological inhibition of FLAT potentiated AEA signaling and produced antinociceptive effects. Given that endocannabinoids produce analgesia through central and peripheral mechanisms, the goal of the current work was to examine the expression of FLAT in the central and peripheral nervous systems. In contrast to the original report characterizing FLAT, expression of FLAT was not observed in any of the tissues examined. To investigate the role of FLAT as a putative AEA binding protein, FLAT was generated from FAAH using polymerase chain reaction and further analyzed. Despite its low cellular expression, FLAT displayed residual catalytic activity that was sensitive to FAAH inhibitors and abolished following mutation of its catalytic serine. Overexpression of FLAT potentiated AEA cellular uptake and this appeared to be dependent upon its catalytic activity. Immunofluorescence revealed that FLAT localizes primarily to intracellular membranes and does not contact the plasma membrane, suggesting that its capability to potentiate AEA uptake may stem from its enzymatic rather than transport activity. Collectively, our data demonstrate that FLAT does not serve as a global intracellular AEA carrier, although a role in mediating localized AEA inactivation in mammalian tissues cannot be ruled out.
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Akerman S, Holland PR, Lasalandra MP, Goadsby PJ. Endocannabinoids in the brainstem modulate dural trigeminovascular nociceptive traffic via CB1 and "triptan" receptors: implications in migraine. J Neurosci 2013; 33:14869-77. [PMID: 24027286 PMCID: PMC3771033 DOI: 10.1523/jneurosci.0943-13.2013] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 08/06/2013] [Accepted: 08/12/2013] [Indexed: 01/07/2023] Open
Abstract
Activation and sensitization of trigeminovascular nociceptive pathways is believed to contribute to the neural substrate of the severe and throbbing nature of pain in migraine. Endocannabinoids, as well as being physiologically analgesic, are known to inhibit dural trigeminovascular nociceptive responses. They are also involved in the descending modulation of cutaneous-evoked C-fiber spinal nociceptive responses from the brainstem. The purpose of this study was to determine whether endocannabinoids are involved in the descending modulation of dural and/or cutaneous facial trigeminovascular nociceptive responses, from the brainstem ventrolateral periaqueductal gray (vlPAG). CB1 receptor activation in the vlPAG attenuated dural-evoked Aδ-fiber neurons (maximally by 19%) and basal spontaneous activity (maximally by 33%) in the rat trigeminocervical complex, but there was no effect on cutaneous facial receptive field responses. This inhibitory vlPAG-mediated modulation was inhibited by specific CB1 receptor antagonism, given via the vlPAG, and with a 5-HT1B/1D receptor antagonist, given either locally in the vlPAG or systemically. These findings demonstrate for the first time that brainstem endocannabinoids provide descending modulation of both basal trigeminovascular neuronal tone and Aδ-fiber dural-nociceptive responses, which differs from the way the brainstem modulates spinal nociceptive transmission. Furthermore, our data demonstrate a novel interaction between serotonergic and endocannabinoid systems in the processing of somatosensory nociceptive information, suggesting that some of the therapeutic action of triptans may be via endocannabinoid containing neurons in the vlPAG.
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Affiliation(s)
- Simon Akerman
- Headache Group, Department of Neurology, University of California, San Francisco, San Francisco, California 94158
| | - Philip R. Holland
- Headache Group, Department of Neurology, University of California, San Francisco, San Francisco, California 94158
| | - Michele P. Lasalandra
- Headache Group, Department of Neurology, University of California, San Francisco, San Francisco, California 94158
| | - Peter J. Goadsby
- Headache Group, Department of Neurology, University of California, San Francisco, San Francisco, California 94158
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Barrière DA, Mallet C, Blomgren A, Simonsen C, Daulhac L, Libert F, Chapuy E, Etienne M, Högestätt ED, Zygmunt PM, Eschalier A. Fatty acid amide hydrolase-dependent generation of antinociceptive drug metabolites acting on TRPV1 in the brain. PLoS One 2013; 8:e70690. [PMID: 23940628 PMCID: PMC3734263 DOI: 10.1371/journal.pone.0070690] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 06/21/2013] [Indexed: 12/11/2022] Open
Abstract
The discovery that paracetamol is metabolized to the potent TRPV1 activator N-(4-hydroxyphenyl)-5Z,8Z,11Z,14Z-eicosatetraenamide (AM404) and that this metabolite contributes to paracetamol’s antinociceptive effect in rodents via activation of TRPV1 in the central nervous system (CNS) has provided a potential strategy for developing novel analgesics. Here we validated this strategy by examining the metabolism and antinociceptive activity of the de-acetylated paracetamol metabolite 4-aminophenol and 4-hydroxy-3-methoxybenzylamine (HMBA), both of which may undergo a fatty acid amide hydrolase (FAAH)-dependent biotransformation to potent TRPV1 activators in the brain. Systemic administration of 4-aminophenol and HMBA led to a dose-dependent formation of AM404 plus N-(4-hydroxyphenyl)-9Z-octadecenamide (HPODA) and arvanil plus olvanil in the mouse brain, respectively. The order of potency of these lipid metabolites as TRPV1 activators was arvanil = olvanil>>AM404> HPODA. Both 4-aminophenol and HMBA displayed antinociceptive activity in various rodent pain tests. The formation of AM404, arvanil and olvanil, but not HPODA, and the antinociceptive effects of 4-aminophenol and HMBA were substantially reduced or disappeared in FAAH null mice. The activity of 4-aminophenol in the mouse formalin, von Frey and tail immersion tests was also lost in TRPV1 null mice. Intracerebroventricular injection of the TRPV1 blocker capsazepine eliminated the antinociceptive effects of 4-aminophenol and HMBA in the mouse formalin test. In the rat, pharmacological inhibition of FAAH, TRPV1, cannabinoid CB1 receptors and spinal 5-HT3 or 5-HT1A receptors, and chemical deletion of bulbospinal serotonergic pathways prevented the antinociceptive action of 4-aminophenol. Thus, the pharmacological profile of 4-aminophenol was identical to that previously reported for paracetamol, supporting our suggestion that this drug metabolite contributes to paracetamol’s analgesic activity via activation of bulbospinal pathways. Our findings demonstrate that it is possible to construct novel antinociceptive drugs based on fatty acid conjugation as a metabolic pathway for the generation of TRPV1 modulators in the CNS.
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Affiliation(s)
- David A. Barrière
- Clermont Université, Université d’Auvergne, Pharmacologie Fondamentale et Clinique de la Douleur, Laboratoire de Pharmacologie, Facultés de Médecine/Pharmacie, Clermont-Ferrand, France
- Inserm, U1107 Neuro-Dol, Clermont-Ferrand, France
| | - Christophe Mallet
- Clermont Université, Université d’Auvergne, Pharmacologie Fondamentale et Clinique de la Douleur, Laboratoire de Pharmacologie, Facultés de Médecine/Pharmacie, Clermont-Ferrand, France
- Inserm, U1107 Neuro-Dol, Clermont-Ferrand, France
| | - Anders Blomgren
- Department of Clinical Chemistry and Pharmacology, Lund University, Lund, Sweden
| | - Charlotte Simonsen
- Department of Clinical Chemistry and Pharmacology, Lund University, Lund, Sweden
| | - Laurence Daulhac
- Clermont Université, Université d’Auvergne, Pharmacologie Fondamentale et Clinique de la Douleur, Laboratoire de Pharmacologie, Facultés de Médecine/Pharmacie, Clermont-Ferrand, France
- Inserm, U1107 Neuro-Dol, Clermont-Ferrand, France
| | - Frédéric Libert
- Clermont Université, Université d’Auvergne, Pharmacologie Fondamentale et Clinique de la Douleur, Laboratoire de Pharmacologie, Facultés de Médecine/Pharmacie, Clermont-Ferrand, France
- Inserm, U1107 Neuro-Dol, Clermont-Ferrand, France
| | - Eric Chapuy
- Clermont Université, Université d’Auvergne, Pharmacologie Fondamentale et Clinique de la Douleur, Laboratoire de Pharmacologie, Facultés de Médecine/Pharmacie, Clermont-Ferrand, France
- Inserm, U1107 Neuro-Dol, Clermont-Ferrand, France
| | - Monique Etienne
- Clermont Université, Université d’Auvergne, Pharmacologie Fondamentale et Clinique de la Douleur, Laboratoire de Pharmacologie, Facultés de Médecine/Pharmacie, Clermont-Ferrand, France
- Inserm, U1107 Neuro-Dol, Clermont-Ferrand, France
| | - Edward D. Högestätt
- Department of Clinical Chemistry and Pharmacology, Lund University, Lund, Sweden
- * E-mail: (AE); (EDH)
| | - Peter M. Zygmunt
- Department of Clinical Chemistry and Pharmacology, Lund University, Lund, Sweden
| | - Alain Eschalier
- Clermont Université, Université d’Auvergne, Pharmacologie Fondamentale et Clinique de la Douleur, Laboratoire de Pharmacologie, Facultés de Médecine/Pharmacie, Clermont-Ferrand, France
- Inserm, U1107 Neuro-Dol, Clermont-Ferrand, France
- CHU Clermont-Ferrand, Service de Pharmacology, Hôpital G. Montpied, Clermont-Ferrand, France
- * E-mail: (AE); (EDH)
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Di Marzo V, De Petrocellis L. Why do cannabinoid receptors have more than one endogenous ligand? Philos Trans R Soc Lond B Biol Sci 2013; 367:3216-28. [PMID: 23108541 DOI: 10.1098/rstb.2011.0382] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The endocannabinoid system was revealed following the understanding of the mechanism of action of marijuana's major psychotropic principle, Δ(9)-tetrahydrocannabinol, and includes two G-protein-coupled receptors (GPCRs; the cannabinoid CB1 and CB2 receptors), their endogenous ligands (the endocannabinoids, the best studied of which are anandamide and 2-arachidonoylglycerol (2-AG)), and the proteins that regulate the levels and activity of these receptors and ligands. However, other minor lipid metabolites different from, but chemically similar to, anandamide and 2-AG have also been suggested to act as endocannabinoids. Thus, unlike most other GPCRs, cannabinoid receptors appear to have more than one endogenous agonist, and it has been often wondered what could be the physiological meaning of this peculiarity. In 1999, it was proposed that anandamide might also activate other targets, and in particular the transient receptor potential of vanilloid type-1 (TRPV1) channels. Over the last decade, this interaction has been shown to occur both in peripheral tissues and brain, during both physiological and pathological conditions. TRPV1 channels can be activated also by another less abundant endocannabinoid, N-arachidonoyldopamine, but not by 2-AG, and have been proposed by some authors to act as ionotropic endocannabinoid receptors. This article will discuss the latest discoveries on this subject, and discuss, among others, how anandamide and 2-AG differential actions at TRPV1 and cannabinoid receptors contribute to making this signalling system a versatile tool available to organisms to fine-tune homeostasis.
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Affiliation(s)
- Vincenzo Di Marzo
- Endocannabinoid Research Group, Istituto Chimica Biomolecolare, CNR, Via Campi Flegrei 34, Comprensorio Olivetti, 80078 Pozzuoli, NA, Italy.
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Fogaça MV, Gomes FV, Moreira FA, Guimarães FS, Aguiar DC. Effects of glutamate NMDA and TRPV1 receptor antagonists on the biphasic responses to anandamide injected into the dorsolateral periaqueductal grey of Wistar rats. Psychopharmacology (Berl) 2013. [PMID: 23183551 DOI: 10.1007/s00213-012-2927-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
RATIONALE The endocannabinoid and endovanniloid anandamide (AEA) exerts biphasic effects when injected into the dorsolateral periaqueductal grey (dlPAG) in rats submitted to threatening situations. Whereas lower doses of AEA induce anxiolytic-like effects by activating cannabinoid CB1 receptors, no effects are observed with higher doses, possibly due to the simultaneous activation of transient receptor potential vanilloid type 1 (TRPV1) receptors. This activation would facilitate glutamatergic neurotransmission. OBJECTIVE Considering that the blockade of TRPV1 or NMDA receptors in the dlPAG induces anxiolytic-like effects, we tested the hypothesis that facilitation of glutamate transmission through TRPV1 is responsible for the lack of anxiolytic-like effect observed with high AEA doses. METHODS Male Wistar rats with a unilateral cannula aimed at the dlPAG received injections of an ineffective dose of AP7 (an NMDA antagonist, 1 nmol) or capsazepine (CPZ, a TRPV1 antagonist, 10 nmol), followed by a high dose of AEA (50 and 200 pmol) and were exposed to the elevated plus maze (EPM) or the Vogel conflict test (VCT). RESULTS AP7, CPZ, or AEA did not induce any significant effects when administered alone. However, AP7 or CPZ prior to AEA significantly increased the percentage of entries and time spent in the open arms of EPM and the number of punished licks in the VCT suggesting an anxiolytic-like effect. CONCLUSIONS These results suggest that the lack of anxiolytic-like effect of higher AEA doses is due to facilitation of glutamate release in the dlPAG, probably via activation of TRPV1 receptors in this structure.
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Affiliation(s)
- Manoela V Fogaça
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, São Paulo 14049900, Brazil
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Almeida-Santos AF, Moreira FA, Guimarães FS, Aguiar DC. Role of TRPV1 receptors on panic-like behaviors mediated by the dorsolateral periaqueductal gray in rats. Pharmacol Biochem Behav 2013; 105:166-72. [PMID: 23474373 DOI: 10.1016/j.pbb.2013.02.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 02/18/2013] [Accepted: 02/23/2013] [Indexed: 12/23/2022]
Abstract
The transient receptors potential vanilloid type 1 channels (TRPV1) are expressed in several brain regions related to defensive behaviors, including the dorsolateral periaqueductal gray (dlPAG). The endocannabinoid anandamide, in addition to its agonist activity at cannabinoid type 1 (CB1), is also proposed as an endogenous agonist of these receptors, through which it could facilitate anxiety-like responses. The aim of this work was to test the hypothesis that TRPV1 in the dlPAG of rats would mediate panic-like responses in two models, namely the escape responses induced by chemical stimulation of this structure or by exposure to the elevated T-Maze (ETM). Antagonism of TRPV1 with capsazepine injected into the dlPAG reduced the defense response induced by local NMDA-injection, suggesting an anti-aversive effect. In the ETM, capsazepine inhibited escape response, suggesting a panicolytic-like effect. Interestingly, this effect was prevented by a CB1 antagonist (AM251). The present study showed that antagonism of TRPV1 in the dlPAG induces panicolytic-like effects, which can be prevented by a CB1 antagonist. Therefore, these antiaversive effects of TRPV1 blockade may ultimately occur due to a predominant action of anandamide through CB1 receptors.
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Affiliation(s)
- A F Almeida-Santos
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil
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Naidoo V, Karanian DA, Vadivel SK, Locklear JR, Wood JT, Nasr M, Quizon PMP, Graves EE, Shukla V, Makriyannis A, Bahr BA. Equipotent inhibition of fatty acid amide hydrolase and monoacylglycerol lipase - dual targets of the endocannabinoid system to protect against seizure pathology. Neurotherapeutics 2012; 9:801-13. [PMID: 22270809 PMCID: PMC3480564 DOI: 10.1007/s13311-011-0100-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Advances in the understanding of the endogenous cannabinoid system have led to several therapeutic indications for new classes of compounds that enhance cannabinergic responses. Endocannabinoid levels are elevated during pathogenic conditions, and inhibitors of endocannabinoid inactivation promote such on-demand responses. The endocannabinoids anandamide and 2-arachidonoyl glycerol have been implicated in protective signaling against excitotoxic episodes, including seizures. To better understand modulatory pathways that can exploit such responses, we used the new generation compound AM6701 that blocks both the anandamide-deactivating enzyme fatty acid amide hydrolase (FAAH) and the 2-arachidonoyl glycerol-deactivating enzyme monoacylglycerol lipase (MAGL) with equal potency. Also studied was the structural isomer AM6702 which is 44-fold more potent for inhibiting FAAH versus MAGL. When applied before and during kainic acid (KA) exposure to cultured hippocampal slices, AM6701 protected against the resulting excitotoxic events of calpain-mediated cytoskeletal damage, loss of presynaptic and postsynaptic proteins, and pyknotic changes in neurons. The equipotent inhibitor was more effective than its close relative AM6702 at protecting against the neurodegenerative cascade assessed in the slice model. In vivo, AM6701 was also the more effective compound for reducing the severity of KA-induced seizures and protecting against behavioral deficits linked to seizure damage. Corresponding with the behavioral improvements, cytoskeletal and synaptic protection was elicited by AM6701, as found in the KA-treated hippocampal slice model. It is proposed that the influence of AM6701 on FAAH and MAGL exerts a synergistic action on the endocannabinoid system, thereby promoting the protective nature of cannabinergic signaling to offset excitotoxic brain injury.
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Affiliation(s)
- Vinogran Naidoo
- Biotechnology Research and Training Center, William C. Friday Laboratory, University of North Carolina Pembroke, Pembroke, North Carolina 28372 USA
- Department of Biology, University of North Carolina Pembroke, Pembroke, North Carolina USA
| | - David A. Karanian
- Department of Pharmaceutical Sciences and the Neurosciences Program, University of Connecticut, Storrs, Connecticut USA
- Center for Drug Discovery, Northeastern University, Boston, Massachusetts USA
| | | | - Johnathan R. Locklear
- Biotechnology Research and Training Center, William C. Friday Laboratory, University of North Carolina Pembroke, Pembroke, North Carolina 28372 USA
| | - JodiAnne T. Wood
- Center for Drug Discovery, Northeastern University, Boston, Massachusetts USA
| | - Mahmoud Nasr
- Center for Drug Discovery, Northeastern University, Boston, Massachusetts USA
| | - Pamela Marie P. Quizon
- Biotechnology Research and Training Center, William C. Friday Laboratory, University of North Carolina Pembroke, Pembroke, North Carolina 28372 USA
| | - Emily E. Graves
- Biotechnology Research and Training Center, William C. Friday Laboratory, University of North Carolina Pembroke, Pembroke, North Carolina 28372 USA
| | - Vidyanand Shukla
- Center for Drug Discovery, Northeastern University, Boston, Massachusetts USA
| | | | - Ben A. Bahr
- Biotechnology Research and Training Center, William C. Friday Laboratory, University of North Carolina Pembroke, Pembroke, North Carolina 28372 USA
- Department of Biology, University of North Carolina Pembroke, Pembroke, North Carolina USA
- Department of Pharmaceutical Sciences and the Neurosciences Program, University of Connecticut, Storrs, Connecticut USA
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50
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Dogrul A, Seyrek M, Yalcin B, Ulugol A. Involvement of descending serotonergic and noradrenergic pathways in CB1 receptor-mediated antinociception. Prog Neuropsychopharmacol Biol Psychiatry 2012; 38:97-105. [PMID: 22300745 DOI: 10.1016/j.pnpbp.2012.01.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 01/03/2012] [Accepted: 01/15/2012] [Indexed: 12/18/2022]
Abstract
Cannabinoids produce antinociceptive and antihyperalgesic effects mainly through activation of the inhibitory CB1 receptors. The demonstration that antinociceptive effects of systemic cannabinoids are significantly diminished following surgical dorsolateral funiculus lesion provides evidence that supraspinal sites and descending pain modulatory pathways play crucial roles in systemic cannabinoid analgesia. In this review, we will firstly provide a background, brief overview of descending modulatory pathways followed by descending pathways implicated in cannabinoid analgesia. We will then describe the recent evidence of the involvement of descending serotonergic and noradrenergic pathways in CB1 receptor-mediated antinociception. This review will provide evidences that systemically administered cannabinoids reinforce the descending serotonergic and noradrenergic pathways to produce acute antinociceptive effects via spinal 5-HT7, 5-HT2A and alpha-2 adrenoceptors activation.
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Affiliation(s)
- Ahmet Dogrul
- Department of Medical Pharmacology, Gulhane Military Academy of Medicine, Ankara, Turkey.
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