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Santi MD, Zhang M, Liu N, Viet CT, Xie T, Jensen DD, Amit M, Pan H, Ye Y. Repurposing EGFR Inhibitors for Oral Cancer Pain and Opioid Tolerance. Pharmaceuticals (Basel) 2023; 16:1558. [PMID: 38004424 PMCID: PMC10674507 DOI: 10.3390/ph16111558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/24/2023] [Accepted: 10/27/2023] [Indexed: 11/26/2023] Open
Abstract
Oral cancer pain remains a significant public health concern. Despite the development of improved treatments, pain continues to be a debilitating clinical feature of the disease, leading to reduced oral mobility and diminished quality of life. Opioids are the gold standard treatment for moderate-to-severe oral cancer pain; however, chronic opioid administration leads to hyperalgesia, tolerance, and dependence. The aim of this review is to present accumulating evidence that epidermal growth factor receptor (EGFR) signaling, often dysregulated in cancer, is also an emerging signaling pathway critically involved in pain and opioid tolerance. We presented preclinical and clinical data to demonstrate how repurposing EGFR inhibitors typically used for cancer treatment could be an effective pharmacological strategy to treat oral cancer pain and to prevent or delay the development of opioid tolerance. We also propose that EGFR interaction with the µ-opioid receptor and glutamate N-methyl-D-aspartate receptor could be two novel downstream mechanisms contributing to pain and morphine tolerance. Most data presented here support that repurposing EGFR inhibitors as non-opioid analgesics in oral cancer pain is promising and warrants further research.
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Affiliation(s)
- Maria Daniela Santi
- Translational Research Center, College of Dentistry, New York University, New York, NY 10010, USA; (M.D.S.); (M.Z.); (N.L.); (D.D.J.)
- Pain Research Center, Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY 10010, USA
| | - Morgan Zhang
- Translational Research Center, College of Dentistry, New York University, New York, NY 10010, USA; (M.D.S.); (M.Z.); (N.L.); (D.D.J.)
- Pain Research Center, Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY 10010, USA
| | - Naijiang Liu
- Translational Research Center, College of Dentistry, New York University, New York, NY 10010, USA; (M.D.S.); (M.Z.); (N.L.); (D.D.J.)
- Pain Research Center, Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY 10010, USA
| | - Chi T. Viet
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA;
| | - Tongxin Xie
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; (T.X.); (M.A.)
| | - Dane D. Jensen
- Translational Research Center, College of Dentistry, New York University, New York, NY 10010, USA; (M.D.S.); (M.Z.); (N.L.); (D.D.J.)
- Pain Research Center, Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY 10010, USA
| | - Moran Amit
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; (T.X.); (M.A.)
| | - Huilin Pan
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Yi Ye
- Translational Research Center, College of Dentistry, New York University, New York, NY 10010, USA; (M.D.S.); (M.Z.); (N.L.); (D.D.J.)
- Pain Research Center, Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY 10010, USA
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Muchhala K, Kang M, Koseli E, Poklis J, Xu Q, Dewey W, Fettweis J, Jimenez N, Akbarali H. The Role of Morphine-Induced Impairment of Intestinal Epithelial Antibacterial Activity in Dysbiosis and its Impact on the Microbiota-Gut-Brain Axis.. [PMID: 37503065 PMCID: PMC10371156 DOI: 10.21203/rs.3.rs-3084467/v2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2024]
Abstract
Abstract
Recent evidence suggests that chronic exposure to opioid analgesics such as morphine disrupt the intestinal epithelial layer and cause intestinal dysbiosis. Inhibiting opioid-induced dysbiosis can preclude the development of tolerance to opioid-induced antinociception, suggesting an important role of the gut-brain axis in mediating opioid effects. However, the mechanism underlying opioid-induced dysbiosis remains unclear. Host-produced antimicrobial peptides (AMPs) are critical for the integrity of the intestinal epithelial barrier as they prevent the pathogenesis of the enteric microbiota. Here, we report that chronic morphine exposure reduces expression of the antimicrobial peptide, Regenerating islet-derived 3 gamma (Reg3γ), in the ileum resulting in reduced intestinal antimicrobial activity against Gram-positive bacteria, L. reuteri. Fecal samples from morphine-treated mice had reduced levels of the phylum, Firmicutes, concomitant with reduced levels of short-chain fatty acid, butyrate. Fecal microbial transplant (FMT) from morphine-naïve mice restored the antimicrobial activity, the expression of Reg3γ, and prevented the increase in intestinal permeability and the development of antinociceptive tolerance in morphine-dependent mice. Similarly, oral gavage with sodium butyrate dose-dependently reduced the development of antinociceptive tolerance, and prevented the downregulation of Reg3γ and the reduction in antimicrobial activity. The alpha diversity of the microbiome was also restored by oral butyrate in morphine-dependent mice. These data implicate impairment of the antimicrobial activity of the intestinal epithelium as a mechanism by which morphine disrupts the microbiota-gut-brain axis.
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Muchhala K, Kang M, Koseli E, Poklis J, Xu Q, Dewey W, Fettweis J, Jimenez N, Akbarali H. The Role of Morphine-Induced Impairment of Intestinal Epithelial Antibacterial Activity in Dysbiosis and its Impact on the Microbiota-Gut-Brain Axis. RESEARCH SQUARE 2023:rs.3.rs-3084467. [PMID: 37503065 PMCID: PMC10371156 DOI: 10.21203/rs.3.rs-3084467/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Recent evidence suggests that chronic exposure to opioid analgesics such as morphine disrupt the intestinal epithelial layer and cause intestinal dysbiosis. Inhibiting opioid-induced dysbiosis can preclude the development of tolerance to opioid-induced antinociception, suggesting an important role of the gut-brain axis in mediating opioid effects. However, the mechanism underlying opioid-induced dysbiosis remains unclear. Host-produced antimicrobial peptides (AMPs) are critical for the integrity of the intestinal epithelial barrier as they prevent the pathogenesis of the enteric microbiota. Here, we report that chronic morphine exposure reduces expression of the antimicrobial peptide, Regenerating islet-derived 3 gamma (Reg3γ), in the ileum resulting in reduced intestinal antimicrobial activity against Gram-positive bacteria, L. reuteri. Fecal samples from morphine-treated mice had reduced levels of the phylum, Firmicutes, concomitant with reduced levels of short-chain fatty acid, butyrate. Fecal microbial transplant (FMT) from morphine-naïve mice restored the antimicrobial activity, the expression of Reg3γ, and prevented the increase in intestinal permeability and the development of antinociceptive tolerance in morphine-dependent mice. Similarly, oral gavage with sodium butyrate dose-dependently reduced the development of antinociceptive tolerance, and prevented the downregulation of Reg3γ and the reduction in antimicrobial activity. The alpha diversity of the microbiome was also restored by oral butyrate in morphine-dependent mice. These data implicate impairment of the antimicrobial activity of the intestinal epithelium as a mechanism by which morphine disrupts the microbiota-gut-brain axis.
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Jin D, Chen H, Zhou MH, Chen SR, Pan HL. mGluR5 from Primary Sensory Neurons Promotes Opioid-Induced Hyperalgesia and Tolerance by Interacting with and Potentiating Synaptic NMDA Receptors. J Neurosci 2023; 43:5593-5607. [PMID: 37451981 PMCID: PMC10401648 DOI: 10.1523/jneurosci.0601-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/29/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023] Open
Abstract
Aberrant activation of presynaptic NMDARs in the spinal dorsal horn is integral to opioid-induced hyperalgesia and analgesic tolerance. However, the signaling mechanisms responsible for opioid-induced NMDAR hyperactivity remain poorly identified. Here, we show that repeated treatment with morphine or fentanyl reduced monomeric mGluR5 protein levels in the dorsal root ganglion (DRG) but increased levels of mGluR5 monomers and homodimers in the spinal cord in mice and rats of both sexes. Coimmunoprecipitation analysis revealed that monomeric and dimeric mGluR5 in the spinal cord, but not monomeric mGluR5 in the DRG, directly interacted with GluN1. By contrast, mGluR5 did not interact with μ-opioid receptors in the DRG or spinal cord. Repeated morphine treatment markedly increased the mGluR5-GluN1 interaction and protein levels of mGluR5 and GluN1 in spinal synaptosomes. The mGluR5 antagonist MPEP reversed morphine treatment-augmented mGluR5-GluN1 interactions, GluN1 synaptic expression, and dorsal root-evoked monosynaptic EPSCs of dorsal horn neurons. Furthermore, CRISPR-Cas9-induced conditional mGluR5 knockdown in DRG neurons normalized mGluR5 levels in spinal synaptosomes and NMDAR-mediated EPSCs of dorsal horn neurons increased by morphine treatment. Correspondingly, intrathecal injection of MPEP or conditional mGluR5 knockdown in DRG neurons not only potentiated the acute analgesic effect of morphine but also attenuated morphine treatment-induced hyperalgesia and tolerance. Together, our findings suggest that opioid treatment promotes mGluR5 trafficking from primary sensory neurons to the spinal dorsal horn. Through dimerization and direct interaction with NMDARs, presynaptic mGluR5 potentiates and/or stabilizes NMDAR synaptic expression and activity at primary afferent central terminals, thereby maintaining opioid-induced hyperalgesia and tolerance.SIGNIFICANCE STATEMENT Opioids are essential analgesics for managing severe pain caused by cancer, surgery, and tissue injury. However, these drugs paradoxically induce pain hypersensitivity and tolerance, which can cause rapid dose escalation and even overdose mortality. This study demonstrates, for the first time, that opioids promote trafficking of mGluR5, a G protein-coupled glutamate receptor, from peripheral sensory neurons to the spinal cord; there, mGluR5 proteins dimerize and physically interact with NMDARs to augment their synaptic expression and activity. Through dynamic interactions, the two distinct glutamate receptors mutually amplify and sustain nociceptive input from peripheral sensory neurons to the spinal cord. Thus, inhibiting mGluR5 activity or disrupting mGluR5-NMDAR interactions could reduce opioid-induced hyperalgesia and tolerance and potentiate opioid analgesic efficacy.
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Affiliation(s)
- Daozhong Jin
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Hong Chen
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Meng-Hua Zhou
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Shao-Rui Chen
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Hui-Lin Pan
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
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Du F, Yin G, Han L, Liu X, Dong D, Duan K, Huo J, Sun Y, Cheng L. Targeting Peripheral μ-opioid Receptors or μ-opioid Receptor-Expressing Neurons Does not Prevent Morphine-induced Mechanical Allodynia and Anti-allodynic Tolerance. Neurosci Bull 2023; 39:1210-1228. [PMID: 36622575 PMCID: PMC10387027 DOI: 10.1007/s12264-022-01009-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/19/2022] [Indexed: 01/10/2023] Open
Abstract
The chronic use of morphine and other opioids is associated with opioid-induced hypersensitivity (OIH) and analgesic tolerance. Among the different forms of OIH and tolerance, the opioid receptors and cell types mediating opioid-induced mechanical allodynia and anti-allodynic tolerance remain unresolved. Here we demonstrated that the loss of peripheral μ-opioid receptors (MORs) or MOR-expressing neurons attenuated thermal tolerance, but did not affect the expression and maintenance of morphine-induced mechanical allodynia and anti-allodynic tolerance. To confirm this result, we made dorsal root ganglia-dorsal roots-sagittal spinal cord slice preparations and recorded low-threshold Aβ-fiber stimulation-evoked inputs and outputs in superficial dorsal horn neurons. Consistent with the behavioral results, peripheral MOR loss did not prevent the opening of Aβ mechanical allodynia pathways in the spinal dorsal horn. Therefore, the peripheral MOR signaling pathway may not be an optimal target for preventing mechanical OIH and analgesic tolerance. Future studies should focus more on central mechanisms.
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Affiliation(s)
- Feng Du
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, 150001, China
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Department of Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Guangjuan Yin
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Department of Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Lei Han
- Department of Anesthesiology, Shenzhen University General Hospital, Shenzhen University, Shenzhen, 518055, China
| | - Xi Liu
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Department of Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Dong Dong
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Department of Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Kaifang Duan
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Department of Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jiantao Huo
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Department of Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Yanyan Sun
- Department of Anesthesiology, Shenzhen University General Hospital, Shenzhen University, Shenzhen, 518055, China.
| | - Longzhen Cheng
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
- Department of Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, China.
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
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Bai X, Zhang K, Ou C, Nie B, Zhang J, Huang Y, Zhang Y, Huang J, Ouyang H, Cao M, Huang W. Selective activation of AKAP150/TRPV1 in ventrolateral periaqueductal gray GABAergic neurons facilitates conditioned place aversion in male mice. Commun Biol 2023; 6:742. [PMID: 37460788 PMCID: PMC10352381 DOI: 10.1038/s42003-023-05106-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 07/06/2023] [Indexed: 07/20/2023] Open
Abstract
Aversion refers to feelings of strong dislike or avoidance toward particular stimuli or situations. Aversion can be caused by pain stimuli and has a long-term negative impact on physical and mental health. Aversion can also be caused by drug abuse withdrawal, resulting in people with substance use disorder to relapse. However, the mechanisms underlying aversion remain unclear. The ventrolateral periaqueductal gray (vlPAG) is considered to play a key role in aversive behavior. Our study showed that inhibition of vlPAG GABAergic neurons significantly attenuated the conditioned place aversion (CPA) induced by hindpaw pain pinch or naloxone-precipitated morphine withdrawal. However, activating or inhibiting glutamatergic neurons, or activating GABAergic neurons cannot affect or alter CPA response. AKAP150 protein expression and phosphorylated TRPV1 (p-TRPV1) were significantly upregulated in these two CPA models. In AKAP150flox/flox mice and C57/B6J wild-type mice, cell-type-selective inhibition of AKAP150 in GABAergic neurons in the vlPAG attenuated aversion. However, downregulating AKAP150 in glutamatergic neurons did not attenuate aversion. Knockdown of AKAP150 in GABAergic neurons effectively reversed the p-TRPV1 upregulation in these two CPA models utilized in our study. Collectively, inhibition of the AKAP150/p-TRPV1 pathway in GABAergic neurons in the vlPAG may be considered a potential therapeutic target for the CPA response.
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Affiliation(s)
- Xiaohui Bai
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
- Department of Anesthesiology, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation. Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Kun Zhang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Chaopeng Ou
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Bilin Nie
- Department of Anesthesiology, Guangdong Women and Children Hospital, Guangzhou, China
| | - Jianxing Zhang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Yongtian Huang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Yingjun Zhang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Jingxiu Huang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Handong Ouyang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.
| | - Minghui Cao
- Department of Anesthesiology, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation. Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
| | - Wan Huang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.
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Brief Opioid Exposure Paradoxically Augments Primary Afferent Input to Spinal Excitatory Neurons via α2δ-1-Dependent Presynaptic NMDA Receptors. J Neurosci 2022; 42:9315-9329. [PMID: 36379705 PMCID: PMC9794381 DOI: 10.1523/jneurosci.1704-22.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/30/2022] [Accepted: 11/03/2022] [Indexed: 11/17/2022] Open
Abstract
Treatment with opioids not only inhibits nociceptive transmission but also elicits a rebound and persistent increase in primary afferent input to the spinal cord. Opioid-elicited long-term potentiation (LTP) from TRPV1-expressing primary afferents plays a major role in opioid-induced hyperalgesia and analgesic tolerance. Here, we determined whether opioid-elicited LTP involves vesicular glutamate transporter-2 (VGluT2) or vesicular GABA transporter (VGAT) neurons in the spinal dorsal horn of male and female mice and identified underlying signaling mechanisms. Spinal cord slice recordings revealed that µ-opioid receptor (MOR) stimulation with DAMGO initially inhibited dorsal root-evoked EPSCs in 87% VGluT2 neurons and subsequently induced LTP in 49% of these neurons. Repeated morphine treatment increased the prevalence of VGluT2 neurons displaying LTP with a short onset latency. In contrast, DAMGO inhibited EPSCs in 46% VGAT neurons but did not elicit LTP in any VGAT neurons even in morphine-treated mice. Spinal superficial laminae were densely innervated by MOR-containing nerve terminals and were occupied by mostly VGluT2 neurons and few VGAT neurons. Furthermore, conditional Grin1 knockout in dorsal root ganglion neurons diminished DAMGO-elicited LTP in lamina II neurons and attenuated hyperalgesia and analgesic tolerance induced by repeated treatment with morphine. In addition, DAMGO-elicited LTP in VGluT2 neurons was abolished by protein kinase C inhibition, gabapentin, Cacna2d1 knockout, or disrupting the α2δ-1-NMDA receptor interaction with an α2δ-1 C terminus peptide. Thus, brief MOR stimulation distinctively potentiates nociceptive primary afferent input to excitatory dorsal horn neurons via α2δ-1-coupled presynaptic NMDA receptors, thereby causing hyperalgesia and reducing analgesic actions of opioids.SIGNIFICANCE STATEMENT Opioid drugs are potent analgesics for treating severe pain and are commonly used during general anesthesia. However, opioid use often induces pain hypersensitivity, rapid loss of analgesic efficacy, and dose escalation, which can cause dependence, addiction, and even overdose fatality. This study demonstrates for the first time that brief opioid exposure preferentially augments primary sensory input to genetically identified glutamatergic excitatory, but not GABAergic/glycinergic inhibitory, neurons in nociceptive dorsal horn circuits. This opioid-elicited synaptic plasticity is cell type specific and mediated by protein kinase C-dependent and α2δ-1-dependent activation of NMDA receptors at primary sensory nerve terminals. These findings elucidate how intraoperative use of opioids for preemptive analgesia paradoxically aggravates postoperative pain and increases opioid consumption and suggest new strategies to improve opioid analgesic efficacy.
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Avci O, Ozdemir E, Taskiran AS, Inan ZDS, Gursoy S. Metformin prevents morphine-induced apoptosis in rats with diabetic neuropathy: a possible mechanism for attenuating morphine tolerance. Naunyn Schmiedebergs Arch Pharmacol 2022; 395:1449-1462. [PMID: 36050544 DOI: 10.1007/s00210-022-02283-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022]
Abstract
Morphine is a drug of choice for the treatment of severe and chronic pain, but tolerance to the antinociceptive effect limits its use. The development of tolerance to morphine has recently been associated with neuronal apoptosis. In this study, our aim was to investigate the effects of metformin on morphine-induced neuronal apoptosis and antinociceptive tolerance in diabetic rats. Three days of cumulative dosing were administered to establish morphine tolerance in rats. The antinociceptive effects of metformin (50 mg/kg) and test dose of morphine (5 mg/kg) were considered at 30-min intervals by thermal antinociceptive tests. To induce diabetic neuropathy, streptozotocin (STZ, 65 mg/kg) was injected intraperitoneally. ELISA kits were used to measure caspase-3, bax, and bcl-2 levels from dorsal root ganglion (DRG) tissue. Semi-quantitative scoring system was used to evaluate apoptotic cells with the the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) method. The findings suggest that co-administration of metformin with morphine to diabetic rats showed a significant increase in antinociceptive effect compared to morphine alone. The antinociceptive tests indicated that metformin significantly attenuated morphine antinociceptive tolerance in diabetic rats. In addition, metformin decreased the levels of apoptotic proteins caspase 3 and Bax in DRG neurons, while significantly increased the levels of antiapoptotic Bcl-2. Semi-quantitative scoring showed that metformin provided a significant reduction in apoptotic cell counts in diabetic rats. These data revealed that metformin demonstrated antiapoptotic activity in diabetic rat DRG neurons and attenuated morphine tolerance. The antiapoptotic activity of metformin probably plays a significant role in reducing morphine tolerance.
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Affiliation(s)
- Onur Avci
- Department of Anesthesiology and Reanimation, Sivas Cumhuriyet University School of Medicine, 58140, Sivas, Turkey
| | - Ercan Ozdemir
- Department of Physiology, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey.
| | - Ahmet Sevki Taskiran
- Department of Physiology, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Zeynep Deniz Sahin Inan
- Department of Histology and Embryology, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Sinan Gursoy
- Department of Anesthesiology and Reanimation, Sivas Cumhuriyet University School of Medicine, 58140, Sivas, Turkey
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9
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Nguyen TL, Nam YS, Lee SY, Jang CG. Repeated Morphine Administration Increases TRPV1 mRNA Expression and Autoradiographic Binding at Supraspinal Sites in the Pain Pathway. Biomol Ther (Seoul) 2022; 30:328-333. [PMID: 35616070 PMCID: PMC9252876 DOI: 10.4062/biomolther.2022.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/18/2022] [Accepted: 04/29/2022] [Indexed: 11/15/2022] Open
Abstract
Repeated morphine administration induces tolerance to its analgesic effects. A previous study reported that repeated morphine treatment activates transient receptor potential vanilloid type 1 (TRPV1) expression in the sciatic nerve, dorsal root ganglion, and spinal cord, contributing to morphine tolerance. In the present study, we analyzed TRPV1 expression and binding sites in supraspinal pain pathways in morphine-tolerant mice. The TRPV1 mRNA levels and binding sites were remarkably increased in the cortex and thalamus of these animals. Our data provide additional insights into the effects of morphine on TRPV1 in the brain and suggest that changes in the expression of, and binding to TRPV1 in the brain are involved in morphine tolerance.
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Affiliation(s)
- Thi-Lien Nguyen
- Department of Pharmacology, School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea.,Pharmacology Laboratory, National Institute of Drug Quality Control, Ha Noi 100000, Viet Nam
| | - Yun-Son Nam
- Department of Pharmacology, School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Seok-Yong Lee
- Department of Pharmacology, School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Choon-Gon Jang
- Department of Pharmacology, School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
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10
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Yang R, Song Y, Wang H, Chen C, Bai F, Li C. BmK DKK13, A Scorpion Toxin, Alleviates Pain Behavior in a Rat Model of Trigeminal Neuralgia by Modulating Voltage-Gated Sodium Channels and MAPKs/CREB Pathway. Mol Neurobiol 2022; 59:4535-4549. [PMID: 35579847 DOI: 10.1007/s12035-022-02855-x] [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: 11/25/2021] [Accepted: 04/27/2022] [Indexed: 12/01/2022]
Abstract
BmK DKK13 (DKK13) is a mutated recombinant peptide, which has a significant antinociception in a rat model of the inflammatory pain. The purpose of this study was to evaluate the antinociceptive effect of DKK13 on trigeminal neuralgia (TN) in rats. Male Sprague-Dawley (SD) rats were treated with the chronic constriction injury of the infraorbital nerve (IoN-CCI) model to induce stable symptoms of TN. DKK13 (1.0 mg/kg, 2.0 mg/kg and 4.0 mg/kg, i.v.) or morphine (4.0 mg/kg, i.v.) was administered by tail vein once on day 14 after IoN-CCI injury. Behavioral tests, electrophysiology and western blotting were performed to investigate the role and underlying mechanisms of DKK13 on IoN-CCI model. Behavioral test results showed that DKK13 could significantly increase the mechanical pain and thermal radiation pain thresholds of IoN-CCI rats and inhibit the asymmetric spontaneous pain scratching behavior. Electrophysiological results showed that DKK13 could significantly reduce the current density of Nav1.8 in the ipsilateral side of trigeminal ganglion (TG) neurons in IoN-CCI rats, and the steady-state activation and inactivation curves of Nav1.8 shifted, respectively, to the direction of hyperpolarization and depolarization. Western blotting results showed that DKK13 significantly reduced the expression of Nav1.8 and the phosphorylation levels of key proteins of MAPKs/CREB pathway in TG tissues of IoN-CCI rats. In brief, DKK13 has a significant antinociceptive effect on IoN-CCI rats, which may be achieved by changing the dynamic characteristics of Nav1.8 channel and regulating the protein phosphorylation in MAPKs/CREB pathway.
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Affiliation(s)
- Ran Yang
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Yongbo Song
- School of Life Sciences and Biopharmaceutical Science, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Haipeng Wang
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Chunyun Chen
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Fei Bai
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Chunli Li
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, China.
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11
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Wang X, Bao C, Li Z, Yue L, Hu L. Side Effects of Opioids Are Ameliorated by Regulating TRPV1 Receptors. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19042387. [PMID: 35206575 PMCID: PMC8872563 DOI: 10.3390/ijerph19042387] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/06/2022] [Accepted: 02/09/2022] [Indexed: 11/23/2022]
Abstract
Humans have used opioids to suppress moderate to severe pain for thousands of years. However, the long-term use of opioids has several adverse effects, such as opioid tolerance, opioid-induced hyperalgesia, and addiction. In addition, the low efficiency of opioids in controlling neuropathic pain limits their clinical applications. Combining nonopioid analgesics with opioids to target multiple sites along the nociceptive pathway may alleviate the side effects of opioids. This study reviews the feasibility of reducing opioid side effects by regulating the transient receptor potential vanilloid 1 (TRPV1) receptors and summarizes the possible underlying mechanisms. Blocking and activating TRPV1 receptors can improve the therapeutic profile of opioids in different manners. TRPV1 and μ-opioid receptors are bidirectionally regulated by β-arrestin2. Thus, drug combinations or developing dual-acting drugs simultaneously targeting μ-opioid and TRPV1 receptors may mitigate opioid tolerance and opioid-induced hyperalgesia. In addition, TRPV1 receptors, especially expressed in the dorsal striatum and nucleus accumbens, participate in mediating opioid reward, and its regulation can reduce the risk of opioid-induced addiction. Finally, co-administration of TRPV1 antagonists and opioids in the primary action sites of the periphery can significantly relieve neuropathic pain. In general, the regulation of TRPV1 may potentially ameliorate the side effects of opioids and enhance their analgesic efficacy in neuropathic pain.
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Affiliation(s)
- Xiaqing Wang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing 100101, China; (X.W.); (C.B.); (Z.L.)
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chongyu Bao
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing 100101, China; (X.W.); (C.B.); (Z.L.)
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenjiang Li
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing 100101, China; (X.W.); (C.B.); (Z.L.)
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lupeng Yue
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing 100101, China; (X.W.); (C.B.); (Z.L.)
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (L.Y.); (L.H.)
| | - Li Hu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing 100101, China; (X.W.); (C.B.); (Z.L.)
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (L.Y.); (L.H.)
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12
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Muchhala KH, Jacob JC, Kang M, Dewey WL, Akbarali HI. The Guts of the Opioid Crisis. Physiology (Bethesda) 2021; 36:315-323. [PMID: 34431418 DOI: 10.1152/physiol.00014.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Bidirectional interactions of the gut epithelium with commensal bacteria are critical for maintaining homeostasis within the gut. Chronic opioid exposure perturbs gut homeostasis through a multitude of neuro-immune-epithelial mechanisms, resulting in the development of analgesic tolerance, a major underpinning of the current opioid crisis. Differences in molecular mechanisms of opioid tolerance between the enteric and central pain pathways pose a significant challenge for managing chronic pain without untoward gastrointestinal effects.
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Affiliation(s)
- Karan H Muchhala
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Joanna C Jacob
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Minho Kang
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
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13
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Muchhala KH, Jacob JC, Dewey WL, Akbarali HI. Role of β-arrestin-2 in short- and long-term opioid tolerance in the dorsal root ganglia. Eur J Pharmacol 2021; 899:174007. [PMID: 33705801 PMCID: PMC8058323 DOI: 10.1016/j.ejphar.2021.174007] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 02/25/2021] [Accepted: 02/28/2021] [Indexed: 11/26/2022]
Abstract
G-protein-biased agonists with reduced β-arrestin-2 activation are being investigated as safer alternatives to clinically-used opioids. β-arrestin-2 has been implicated in the mechanism of opioid-induced antinociceptive tolerance. Opioid-induced analgesic tolerance is classically considered as centrally-mediated, but recent reports implicate nociceptive dorsal root ganglia neurons as critical mediators in this process. Here, we investigated the role of β-arrestin-2 in the mechanism of opioid tolerance in dorsal root ganglia nociceptive neurons using β-arrestin-2 knockout mice and the G-protein-biased μ-opioid receptor agonist, TRV130. Whole-cell current-clamp electrophysiology experiments revealed that 15-18-h overnight exposure to 10 μM morphine in vitro induced acute tolerance in β-arrestin-2 wild-type but not knockout neurons. Furthermore, in wild-type neurons circumventing β-arrestin-2 activation by overnight treatment with 200 nM TRV130 attenuated tolerance. Similarly, acute morphine tolerance in vivo in β-arrestin-2 knockout mice was prevented in the warm-water tail-withdrawal assay. Treatment with 30 mg/kg TRV130 s.c. also inhibited acute antinociceptive tolerance in vivo in wild-type mice. Alternately, in β-arrestin-2 knockout neurons tolerance induced by 7-day in vivo exposure to 50 mg morphine pellet was conserved. Likewise, β-arrestin-2 deletion did not mitigate in vivo antinociceptive tolerance induced by 7-day exposure to 25 mg or 50 mg morphine pellet in both female or male mice, respectively. Consequently, these results indicated that β-arrestin-2 mediates acute but not chronic opioid tolerance in dorsal root ganglia neurons and to antinociception in vivo. This suggests that opioid-induced antinociceptive tolerance may develop even in the absence of β-arrestin-2 activation, and thus significantly affect the clinical utility of biased agonists.
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MESH Headings
- Analgesics, Opioid/pharmacology
- Animals
- Behavior, Animal/drug effects
- Cells, Cultured
- Disease Models, Animal
- Drug Tolerance
- Female
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/metabolism
- Ganglia, Spinal/physiopathology
- Male
- Mice, Knockout
- Morphine/pharmacology
- Neurons/drug effects
- Neurons/metabolism
- Nociceptive Pain/genetics
- Nociceptive Pain/metabolism
- Nociceptive Pain/physiopathology
- Nociceptive Pain/prevention & control
- Pain Threshold/drug effects
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/metabolism
- Spiro Compounds/pharmacology
- Thiophenes/pharmacology
- Time Factors
- beta-Arrestin 2/deficiency
- beta-Arrestin 2/genetics
- beta-Arrestin 2/metabolism
- Mice
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Affiliation(s)
- Karan H Muchhala
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 East Clay St, Richmond, VA, 23298, USA
| | - Joanna C Jacob
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 East Clay St, Richmond, VA, 23298, USA
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 East Clay St, Richmond, VA, 23298, USA
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 East Clay St, Richmond, VA, 23298, USA.
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14
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α2δ-1-Bound N-Methyl-D-aspartate Receptors Mediate Morphine-induced Hyperalgesia and Analgesic Tolerance by Potentiating Glutamatergic Input in Rodents. Anesthesiology 2020; 130:804-819. [PMID: 30839350 DOI: 10.1097/aln.0000000000002648] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Chronic use of μ-opioid receptor agonists paradoxically causes both hyperalgesia and the loss of analgesic efficacy. Opioid treatment increases presynaptic N-methyl-D-aspartate receptor activity to potentiate nociceptive input to spinal dorsal horn neurons. However, the mechanism responsible for this opioid-induced activation of presynaptic N-methyl-D-aspartate receptors remains unclear. α2δ-1, formerly known as a calcium channel subunit, interacts with N-methyl-D-aspartate receptors and is primarily expressed at presynaptic terminals. This study tested the hypothesis that α2δ-1-bound N-methyl-D-aspartate receptors contribute to presynaptic N-methyl-D-aspartate receptor hyperactivity associated with opioid-induced hyperalgesia and analgesic tolerance. METHODS Rats (5 mg/kg) and wild-type and α2δ-1-knockout mice (10 mg/kg) were treated intraperitoneally with morphine twice/day for 8 consecutive days, and nociceptive thresholds were examined. Presynaptic N-methyl-D-aspartate receptor activity was recorded in spinal cord slices. Coimmunoprecipitation was performed to examine protein-protein interactions. RESULTS Chronic morphine treatment in rats increased α2δ-1 protein amounts in the dorsal root ganglion and spinal cord. Chronic morphine exposure also increased the physical interaction between α2δ-1 and N-methyl-D-aspartate receptors by 1.5 ± 0.3 fold (means ± SD, P = 0.009, n = 6) and the prevalence of α2δ-1-bound N-methyl-D-aspartate receptors at spinal cord synapses. Inhibiting α2δ-1 with gabapentin or genetic knockout of α2δ-1 abolished the increase in presynaptic N-methyl-D-aspartate receptor activity in the spinal dorsal horn induced by morphine treatment. Furthermore, uncoupling the α2δ-1-N-methyl-D-aspartate receptor interaction with an α2δ-1 C terminus-interfering peptide fully reversed morphine-induced tonic activation of N-methyl-D-aspartate receptors at the central terminal of primary afferents. Finally, intraperitoneal injection of gabapentin or intrathecal injection of an α2δ-1 C terminus-interfering peptide or α2δ-1 genetic knockout abolished the mechanical and thermal hyperalgesia induced by chronic morphine exposure and largely preserved morphine's analgesic effect during 8 days of morphine treatment. CONCLUSIONS α2δ-1-Bound N-methyl-D-aspartate receptors contribute to opioid-induced hyperalgesia and tolerance by augmenting presynaptic N-methyl-D-aspartate receptor expression and activity at the spinal cord level.
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15
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Mazeto TK, Picada JN, Correa ÁP, Rebelo IN, Ribeiro MT, Gomez MV, de Souza AH. Antinociceptive and genotoxic assessments of the antagonist TRPV1 receptor SB-366791 on morphine-induced tolerance in mice. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2020; 393:481-490. [PMID: 31655852 DOI: 10.1007/s00210-019-01748-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 10/09/2019] [Indexed: 12/17/2022]
Abstract
Chronic pain is mainly treated with opioid analgesics such as morphine. However, the use of these substances can cause adverse effects, including dependence and tolerance, necessitating the discovery of a new approach to analgesic therapies. The transient receptor potential vanilloid 1 (TRPV1) is linked to thermal sensibility and has been considered as a new therapeutic option for pain treatment. This study aims to investigate the antinociceptive effect and toxicity of SB-366791, a TRPV1 antagonist. Morphine-tolerant and morphine non-tolerant Swiss mice were submitted to the hot plate and thermal tail flick tests. Toxicological evaluations of the genotoxic and mutagenic activities of SB-366791 were assessed using a comet assay and micronucleus test, and the Salmonella/microsome mutagenicity assay. In the hot plate test, intrathecal injection of SB-366791 or morphine resulted in significantly increased antinociception in non-tolerant mice. SB-366791 also led to an analgesic effect in the tail flick test. Tolerant mice that received SB-366791 demonstrated a central antinociceptive effect in both thermal tests. No genotoxic effects were observed in the comet assay and no mutagenic effects were detected in the micronucleus test or in the Salmonella/microsome assay. Behavioral results of the thermal nociception tests show that SB-366791 has antinociceptive potential in both morphine-tolerant and non-tolerant mice and does not cause genotoxic or mutagenic effects. Nevertheless, new studies should be performed to clarify the activity and participation of vanilloid channels in the antinociception of SB-366791.
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Affiliation(s)
- Thiago Kastell Mazeto
- Graduate Program in Cellular and Molecular Biology Applied to Health Sciences, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
| | - Jaqueline Nascimento Picada
- Graduate Program in Cellular and Molecular Biology Applied to Health Sciences, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil.
- Graduate Program in Genetics and Applied Toxicology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil.
| | - Áurea Pandolfo Correa
- Department of Pharmacology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
| | - Isadora Nunes Rebelo
- Department of Pharmacology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
| | - Magali Terra Ribeiro
- Graduate Program in Genetics and Applied Toxicology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
| | - Marcus Vinícius Gomez
- Department of Neurotransmitters, Institute for Education and Research, Hospital Santa Casa, Domingos Vieira Street, 590, Belo Horizonte, MG, CEP 30150-240, Brazil
| | - Alessandra Hubner de Souza
- Graduate Program in Cellular and Molecular Biology Applied to Health Sciences, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
- Graduate Program in Genetics and Applied Toxicology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
- Department of Pharmacology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
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16
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μ-Opioid receptors in primary sensory neurons are involved in supraspinal opioid analgesia. Brain Res 2019; 1729:146623. [PMID: 31881186 DOI: 10.1016/j.brainres.2019.146623] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/20/2019] [Accepted: 12/23/2019] [Indexed: 11/21/2022]
Abstract
Both inhibiting ascending nociceptive transmission and activating descending inhibition are involved in the opioid analgesic effect. The spinal dorsal horn is a critical site for modulating nociceptive transmission by descending pathways elicited by opioids in the brain. μ-Opioid receptors (MORs, encoded by Oprm1) are highly expressed in primary sensory neurons and their central terminals in the spinal cord. In the present study, we tested the hypothesis that MORs expressed in primary sensory neurons contribute to the descending inhibition and supraspinal analgesic effect induced by centrally administered opioids. We generated Oprm1 conditional knockout (Oprm1-cKO) mice by crossing AdvillinCre/+ mice with Oprm1flox/flox mice. Immunocytochemical labeling in Oprm1-cKO mice showed that MORs are completely ablated from primary sensory neurons and are profoundly reduced in the superficial spinal dorsal horn. Intracerebroventricular injection of morphine or fentanyl produced a potent analgesic effect in wild-type mice, but such an effect was significantly attenuated in Oprm1-cKO mice. Furthermore, the analgesic effect produced by morphine or fentanyl microinjected into the periaqueductal gray was significantly greater in wild-type mice than in Oprm1-cKO mice. Blocking MORs at the spinal cord level diminished the analgesic effect of morphine and fentanyl microinjected into the periaqueductal gray in both groups of mice. Our findings indicate that MORs expressed at primary afferent terminals in the spinal cord contribute to the supraspinal opioid analgesic effect. These presynaptic MORs in the spinal cord may serve as an interface between ascending inhibition and descending modulation that are involved in opioid analgesia.
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17
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Matak I, Bölcskei K, Bach-Rojecky L, Helyes Z. Mechanisms of Botulinum Toxin Type A Action on Pain. Toxins (Basel) 2019; 11:E459. [PMID: 31387301 PMCID: PMC6723487 DOI: 10.3390/toxins11080459] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 07/26/2019] [Accepted: 07/29/2019] [Indexed: 12/31/2022] Open
Abstract
Already a well-established treatment for different autonomic and movement disorders, the use of botulinum toxin type A (BoNT/A) in pain conditions is now continuously expanding. Currently, the only approved use of BoNT/A in relation to pain is the treatment of chronic migraines. However, controlled clinical studies show promising results in neuropathic and other chronic pain disorders. In comparison with other conventional and non-conventional analgesic drugs, the greatest advantages of BoNT/A use are its sustained effect after a single application and its safety. Its efficacy in certain therapy-resistant pain conditions is of special importance. Novel results in recent years has led to a better understanding of its actions, although further experimental and clinical research is warranted. Here, we summarize the effects contributing to these advantageous properties of BoNT/A in pain therapy, specific actions along the nociceptive pathway, consequences of its central activities, the molecular mechanisms of actions in neurons, and general pharmacokinetic parameters.
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Affiliation(s)
- Ivica Matak
- Department of Pharmacology, University of Zagreb School of Medicine, Šalata 11, 10000 Zagreb, Croatia.
| | - Kata Bölcskei
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti út 12, 7624 Pécs, Hungary
- János Szentágothai Research Center, Center for Neuroscience, University of Pécs, Ifjúság útja 20, 7624 Pécs, Hungary
| | - Lidija Bach-Rojecky
- Department of Pharmacology, University of Zagreb Faculty of Pharmacy and Biochemistry, Domagojeva 2, 10000 Zagreb, Croatia
| | - Zsuzsanna Helyes
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti út 12, 7624 Pécs, Hungary
- János Szentágothai Research Center, Center for Neuroscience, University of Pécs, Ifjúság útja 20, 7624 Pécs, Hungary
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18
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Sun J, Chen SR, Chen H, Pan HL. μ-Opioid receptors in primary sensory neurons are essential for opioid analgesic effect on acute and inflammatory pain and opioid-induced hyperalgesia. J Physiol 2019; 597:1661-1675. [PMID: 30578671 DOI: 10.1113/jp277428] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/17/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS μ-Opioid receptors (MORs) are expressed peripherally and centrally, but the loci of MORs responsible for clinically relevant opioid analgesia are uncertain. Crossing Oprm1flox/flox and AdvillinCre/+ mice completely ablates MORs in dorsal root ganglion neurons and reduces the MOR expression level in the spinal cord. Presynaptic MORs expressed at primary afferent central terminals are essential for synaptic inhibition and potentiation of sensory input by opioids. MOR ablation in primary sensory neurons diminishes analgesic effects produced by systemic and intrathecal opioid agonists and abolishes chronic opioid treatment-induced hyperalgesia. These findings demonstrate a critical role of MORs expressed in primary sensory neurons in opioid analgesia and suggest new strategies to increase the efficacy and reduce adverse effects of opioids. ABSTRACT The pain and analgesic systems are complex, and the actions of systemically administered opioids may be mediated by simultaneous activation of μ-opioid receptors (MORs, encoded by the Oprm1 gene) at multiple, interacting sites. The loci of MORs and circuits responsible for systemic opioid-induced analgesia and hyperalgesia remain unclear. Previous studies using mice in which MORs are removed from Nav1.8- or TRPV1-expressing neurons provided only an incomplete and erroneous view about the role of peripheral MORs in opioid actions in vivo. In the present study, we determined the specific role of MORs expressed in primary sensory neurons in the analgesic and hyperalgesic effects produced by systemic opioid administration. We generated Oprm1 conditional knockout (Oprm1-cKO) mice in which MOR expression is completely deleted from dorsal root ganglion neurons and substantially reduced in the spinal cord, which was confirmed by immunoblotting and immunocytochemical labelling. Both opioid-induced inhibition and potentiation of primary sensory input were abrogated in Oprm1-cKO mice. Remarkably, systemically administered morphine potently inhibited acute thermal and mechanical nociception and persistent inflammatory pain in control mice but had little effect in Oprm1-cKO mice. The analgesic effect of intrathecally administered morphine was also profoundly reduced in Oprm1-cKO mice. Additionally, chronic morphine treatment-induced hyperalgesia was absent in Oprm1-cKO mice. Our findings directly challenge the notion that clinically relevant opioid analgesia is mediated mostly by centrally expressed MORs. MORs in primary sensory neurons, particularly those expressed presynaptically at the first sensory synapse in the spinal cord, are crucial for both opioid analgesia and opioid-induced hyperalgesia.
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Affiliation(s)
- Jie Sun
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Anesthesiology, The First Affiliated Hospital/Jiangsu Province Hospital, Nanjing Medical University, Nanjing, Jiangsu, 210029, China
| | - Shao-Rui Chen
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Hong Chen
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Hui-Lin Pan
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
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19
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Deng M, Chen SR, Chen H, Luo Y, Dong Y, Pan HL. Mitogen-activated protein kinase signaling mediates opioid-induced presynaptic NMDA receptor activation and analgesic tolerance. J Neurochem 2018; 148:275-290. [PMID: 30444263 DOI: 10.1111/jnc.14628] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 11/01/2018] [Accepted: 11/09/2018] [Indexed: 12/15/2022]
Abstract
Opioid-induced hyperalgesia and analgesic tolerance can lead to dose escalation and inadequate pain treatment with μ-opioid receptor agonists. Opioids cause tonic activation of glutamate NMDA receptors (NMDARs) at primary afferent terminals, increasing nociceptive input. However, the signaling mechanisms responsible for opioid-induced activation of pre-synaptic NMDARs in the spinal dorsal horn remain unclear. In this study, we determined the role of MAPK signaling in opioid-induced pre-synaptic NMDAR activation caused by chronic morphine administration. Whole-cell recordings of excitatory post-synaptic currents (EPSCs) were performed on dorsal horn neurons in rat spinal cord slices. Chronic morphine administration markedly increased the frequency of miniature EPSCs, increased the amplitude of monosynaptic EPSCs evoked from the dorsal root, and reduced the paired-pulse ratio of evoked EPSCs. These changes were fully reversed by an NMDAR antagonist and normalized by inhibiting extracellular signal-regulated kinase 1/2 (ERK1/2), p38, or c-Jun N-terminal kinase (JNK). Furthermore, intrathecal injection of a selective ERK1/2, p38, or JNK inhibitor blocked pain hypersensitivity induced by chronic morphine treatment. These inhibitors also similarly attenuated a reduction in morphine's analgesic effect in rats. In addition, co-immunoprecipitation assays revealed that NMDARs formed a protein complex with ERK1/2, p38, and JNK in the spinal cord and that chronic morphine treatment increased physical interactions of NMDARs with these three MAPKs. Our findings suggest that opioid-induced hyperalgesia and analgesic tolerance are mediated by tonic activation of pre-synaptic NMDARs via three functionally interrelated MAPKs at the spinal cord level. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Meichun Deng
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Shao-Rui Chen
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Hong Chen
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Yi Luo
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Clinical Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Yingchun Dong
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Anesthesiology, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Hui-Lin Pan
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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20
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Wang W, Ma X, Luo L, Huang M, Dong J, Zhang X, Jiang W, Xu T. Exchange factor directly activated by cAMP-PKCε signalling mediates chronic morphine-induced expression of purine P2X3 receptor in rat dorsal root ganglia. Br J Pharmacol 2018; 175:1760-1769. [PMID: 29500928 DOI: 10.1111/bph.14191] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE The P2X3 receptor is a major receptor in the processing of nociceptive information in dorsal root ganglia. We investigated the role of the P2X3 receptor and the detailed mechanisms underlying chronic morphine-induced analgesic tolerance in rats. EXPERIMENTAL APPROACH Repeated i.t. morphine treatment was used to induce anti-nociceptive tolerance. The expression of spinal P2X3 receptor, phosphorylated PKCε and exchange factor directly activated by cAMP (Epac) were evaluated. Effects of A-317491 (P2X3 antagonist), ε-V1-2 (PKCε inhibitor) and ESI-09 (Epac inhibitor) on mechanical pain thresholds and tail-flick latency after chronic morphine treatment were determined. Co-localization of P2X3 receptor with NeuNs (marker of neuron), IB4 (marker of small DRG neurons), peripherin, PKCε and Epac were performed by double immunofluorescence staining. KEY RESULTS Chronic morphine time-dependently increased the expression of P2X3 receptor, phosphorylated PKCε and Epac in DRGs. ε-V1-2 prevented chronic morphine-induced expression of P2X3 receptor. ESI-09 decreased the phosphorylation of PKCε and up-regulated expression of Epac after chronic morphine exposure. Mechanical pain thresholds and tail-flick latency showed that A317491, ε-V1-2 and ESI-09 significantly attenuated the loss of morphine's analgesic potency. Morphine-induced P2X3 receptor expression mainly occurred in neurons staining for IB4 and peripherin. Co-localization of P2X3 receptor with PKCε and Epac was demonstrated in the same neurons. CONCLUSIONS AND IMPLICATIONS Chronic morphine exposure increased the expression of P2X3 receptor, and i.t. P2X3 receptor antagonists attenuated the loss of morphine's analgesic effect. Inhibiting Epac/PKCε signalling was shown to play a significant inhibitory role in chronic morphine-induced P2X3 receptor expression and attenuate morphine-induced tolerance.
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Affiliation(s)
- Wenying Wang
- Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaqing Ma
- Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.,Department of Anesthesiology, Nantong Third People's Hospital, Nantong University, Nantong, China
| | - Limin Luo
- Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Min Huang
- Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Jing Dong
- Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaoli Zhang
- Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Wei Jiang
- Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Tao Xu
- Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.,Department of Anesthesiology, Tongzhou People's Hospital, Nantong, China
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Zhang X, Chen S, Chen H, Pan H, Zhao Y. Inhibition of β-ARK1 Ameliorates Morphine-induced Tolerance and Hyperalgesia Via Modulating the Activity of Spinal NMDA Receptors. Mol Neurobiol 2017; 55:5393-5407. [DOI: 10.1007/s12035-017-0780-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 09/19/2017] [Indexed: 02/02/2023]
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Corder G, Tawfik VL, Wang D, Sypek EI, Low SA, Dickinson JR, Sotoudeh C, Clark JD, Barres BA, Bohlen CJ, Scherrer G. Loss of μ opioid receptor signaling in nociceptors, but not microglia, abrogates morphine tolerance without disrupting analgesia. Nat Med 2017; 23:164-173. [PMID: 28092666 PMCID: PMC5296291 DOI: 10.1038/nm.4262] [Citation(s) in RCA: 241] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 12/05/2016] [Indexed: 12/11/2022]
Abstract
Opioid pain medications have detrimental side effects including analgesic tolerance and opioid-induced hyperalgesia (OIH). Tolerance and OIH counteract opioid analgesia and drive dose escalation. The cell types and receptors on which opioids act to initiate these maladaptive processes remain disputed, which has prevented the development of therapies to maximize and sustain opioid analgesic efficacy. We found that μ opioid receptors (MORs) expressed by primary afferent nociceptors initiate tolerance and OIH development. RNA sequencing and histological analysis revealed that MORs are expressed by nociceptors, but not by spinal microglia. Deletion of MORs specifically in nociceptors eliminated morphine tolerance, OIH and pronociceptive synaptic long-term potentiation without altering antinociception. Furthermore, we found that co-administration of methylnaltrexone bromide, a peripherally restricted MOR antagonist, was sufficient to abrogate morphine tolerance and OIH without diminishing antinociception in perioperative and chronic pain models. Collectively, our data support the idea that opioid agonists can be combined with peripheral MOR antagonists to limit analgesic tolerance and OIH.
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Affiliation(s)
- Gregory Corder
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California, USA
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
- Stanford Neurosciences Institute, Stanford, CA 94305, USA
| | - Vivianne L. Tawfik
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California, USA
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
- Stanford Neurosciences Institute, Stanford, CA 94305, USA
| | - Dong Wang
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California, USA
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
- Stanford Neurosciences Institute, Stanford, CA 94305, USA
| | - Elizabeth I. Sypek
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA
- Stanford University Neuroscience Graduate Program, Stanford, CA 94305, USA
| | - Sarah A. Low
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California, USA
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
- Stanford Neurosciences Institute, Stanford, CA 94305, USA
| | - Jasmine R. Dickinson
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA
- Stanford University Biology Graduate Program, Stanford, CA 94305, USA
| | - Chaudy Sotoudeh
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California, USA
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
- Stanford Neurosciences Institute, Stanford, CA 94305, USA
| | - J. David Clark
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA
- Anesthesiology Service, Veteran’s Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA
| | - Ben A. Barres
- Stanford Neurosciences Institute, Stanford, CA 94305, USA
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA
| | - Christopher J. Bohlen
- Stanford Neurosciences Institute, Stanford, CA 94305, USA
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA
| | - Grégory Scherrer
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California, USA
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
- Stanford Neurosciences Institute, Stanford, CA 94305, USA
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Yadlapalli JSK, Ford BM, Ketkar A, Wan A, Penthala NR, Eoff RL, Prather PL, Dobretsov M, Crooks PA. Antinociceptive effects of the 6-O-sulfate ester of morphine in normal and diabetic rats: Comparative role of mu- and delta-opioid receptors. Pharmacol Res 2016; 113:335-347. [PMID: 27637375 DOI: 10.1016/j.phrs.2016.09.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 08/30/2016] [Accepted: 09/12/2016] [Indexed: 12/20/2022]
Abstract
This study determined the antinociceptive effects of morphine and morphine-6-O-sulfate (M6S) in both normal and diabetic rats, and evaluated the comparative role of mu-opioid receptors (mu-ORs) and delta-opioid receptors (delta-ORs) in the antinociceptive action of these opioids. In vitro characterization of mu-OR and delta-OR-mediated signaling by M6S and morphine in stably transfected Chinese hamster ovary (CHO-K1) cells showed that M6S exhibited a 6-fold higher affinity for delta-ORs and modulated G-protein and adenylyl cyclase activity via delta-ORs more potently than morphine. Interestingly, while morphine acted as a full agonist at delta-ORs in both functional assays examined, M6S exhibited either partial or full agonist activity for modulation of G-protein or adenylyl cyclase activity, respectively. Molecular docking studies indicated that M6S but not morphine binds equally well at the ligand binding site of both mu- and delta-ORs. In vivo analgesic effects of M6S and morphine in both normal and streptozotocin-induced diabetic Sprague-Dawley rats utilizing the hot water tail flick latency test showed that M6S produced more potent antinociception than morphine in both normal rats and diabetic rats. This difference in potency was abrogated following antagonism of delta- but not mu- or kappa (kappa-ORs) opioid receptors. During 9days of chronic treatment, tolerance developed to morphine-treated but not to M6S-treated rats. Rats that developed tolerance to morphine still remained responsive to M6S. Collectively, this study demonstrates that M6S is a potent and efficacious mu/delta opioid analgesic with a delayed tolerance profile when compared to morphine in both normal and diabetic rats. PERSPECTIVE This study demonstrates that M6S acts at both mu- and delta-ORs, and adds to the growing evidence that the use of mixed mu/delta opioid agonists in pain treatment may have clinical benefit.
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Affiliation(s)
- Jai Shankar K Yadlapalli
- Departments of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Benjamin M Ford
- Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Amit Ketkar
- Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Anqi Wan
- Departments of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Narasimha R Penthala
- Departments of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Robert L Eoff
- Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Paul L Prather
- Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Maxim Dobretsov
- Anesthesiology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Peter A Crooks
- Departments of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
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Abstract
In recent years, studies have substantiated the view that P2X3 receptors play a part in the generation and transmission of purinergic signals in inflammatory and chronic neuropathic pain. Data have also been presented to suggest that the process of P2X3 receptor antagonism inhibits inflammatory hyperalgesia, involving the spinal opioid system. The aim of this study was to investigate the effect of the selective P2X3 receptor antagonist A-317491 on the development of antinociceptive tolerance to chronic morphine administration in mice. Daily systemic injection of A-317491 attenuated the morphine-induced antinociceptive tolerance to von Frey and thermal stimuli. Repeated morphine injections alone led to a significant rightward shift in the morphine dose-response curve compared with that with A-317491. A single dose of A-317491 also showed a reversal effect in morphine-tolerant mice. In a withdrawal test, co-administration of A-317491 and morphine also reduced the naloxone-induced withdrawal symptoms compared with the morphine-alone group. Thus, we propose that the P2X3 receptor is involved in the process of morphine antinociceptive tolerance and may be a new therapeutic target in the prevention of tolerance to morphine-induced antinociception.
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25
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Bao Y, Gao Y, Yang L, Kong X, Yu J, Hou W, Hua B. The mechanism of μ-opioid receptor (MOR)-TRPV1 crosstalk in TRPV1 activation involves morphine anti-nociception, tolerance and dependence. Channels (Austin) 2015; 9:235-43. [PMID: 26176938 DOI: 10.1080/19336950.2015.1069450] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Initiated by the activation of various nociceptors, pain is a reaction to specific stimulus modalities. The μ-opioid receptor (MOR) agonists, including morphine, remain the most potent analgesics to treat patients with moderate to severe pain. However, the utility of MOR agonists is limited by the adverse effects associated with the use of these drugs, including analgesic tolerance and physical dependence. A strong connection has been suggested between the expression of the transient receptor potential vanilloid type 1 (TRPV1) ion channel and the development of inflammatory hyperalgesia. TRPV1 is important for thermal nociception induction, and is mainly expressed on sensory neurons. Recent reports suggest that opioid or TRPV1 receptor agonist exposure has contrasting consequences for anti-nociception, tolerance and dependence. Chronic morphine exposure modulates TRPV1 activation and induces the anti-nociception effects of morphine. The regulation of many downstream targets of TRPV1 plays a critical role in this process, including calcitonin gene-related peptide (CGRP) and substance P (SP). Additional factors also include capsaicin treatment blocking the anti-nociception effects of morphine in rats, as well as opioid modulation of TRPV1 responses through the cAMP-dependent PKA pathway and MAPK signaling pathways. Here, we review new insights concerning the mechanism underlying MOR-TRPV1 crosstalk and signaling pathways and discuss the potential mechanisms of morphine-induced anti-nociception, tolerance and dependence associated with the TRPV1 signaling pathway and highlight how understanding these mechanisms might help find therapeutic targets for the treatment of morphine induced antinociception, tolerance and dependence.
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Affiliation(s)
- Yanju Bao
- a Department of Oncology ; Guang'anmen Hospital, China Academy of Chinese Medical Sciences ; Beijing , P. R. China
| | - Yebo Gao
- a Department of Oncology ; Guang'anmen Hospital, China Academy of Chinese Medical Sciences ; Beijing , P. R. China.,b Beijing University of Chinese Medicine ; Beijing , P. R. China
| | - Liping Yang
- c Department of Nephrology ; Guang'anmen Hospital, China Academy of Chinese Medical Sciences ; Beijing , P. R. China
| | - Xiangying Kong
- d Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences ; Beijing , P. R. China
| | - Jing Yu
- e Department of Oncology ; Beijing Friendship Hospital, Capital Medical University ; Beijing , China
| | - Wei Hou
- a Department of Oncology ; Guang'anmen Hospital, China Academy of Chinese Medical Sciences ; Beijing , P. R. China
| | - Baojin Hua
- a Department of Oncology ; Guang'anmen Hospital, China Academy of Chinese Medical Sciences ; Beijing , P. R. China
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Hakimizadeh E, Kazemi Arababadi M, Shamsizadeh A, Allahtavakoli M, Rezvani ME, Roohbakhsh A. Morphine Reduces Expression of TRPV1 Receptors in the Amygdala but not in the Hippocampus of Male Rats. IRANIAN JOURNAL OF MEDICAL SCIENCES 2014; 39:261-7. [PMID: 24850983 PMCID: PMC4027005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 03/12/2013] [Accepted: 05/05/2013] [Indexed: 11/18/2022]
Abstract
BACKGROUND Chronic use of opioids usually results in physical dependence. The underlying mechanisms for this dependence are still being evaluated. Transient receptor potential vanilloid type 1 (TRPV1) are important receptors of pain perception. Their role during opioid dependence has not been studied well. The aim of this study was to evaluate the effect of morphine-dependence on the expression of TRPV1 receptors in the amygdala and CA1 region of the hippocampus. METHODS This study used four groups of rats. Two groups of rats (morphine and morphine+naloxone) received morphine based on the following protocol: 10 mg/kg (twice daily, 3 days) followed by 20, 30, 40 and 50 mg/kg (twice daily), respectively, for 4 consecutive days. Another group received vehicle (1 ml/kg) instead of morphine given using the same schedule. The morphine+naloxone group of rats additionally received naloxone (5 mg/kg) at the end of the protocol. The control group rats received no injections or intervention. The amygdala and CA1 regions of the morphine, saline-treated and intact animals were isolated and prepared for real-time PCR analysis. RESULTS Administration of naloxone induced withdrawal signs in morphine-treated animals. The results showed a significant decrease in TRPV1 gene expression in the amygdala (P<0.05) but not the CA1 region of morphine dependent rats. CONCLUSION TRPV1 receptors may be involved in morphine-induced dependence.
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Affiliation(s)
- Elham Hakimizadeh
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran;
| | - Mohammad Kazemi Arababadi
- Immunology of Infectious Diseases Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran;
| | - Ali Shamsizadeh
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran;
| | - Mohammad Allahtavakoli
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran;
| | - Mohammad Ebrahim Rezvani
- Department of Physiology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran;
| | - Ali Roohbakhsh
- Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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Song Z, Guo Q, Zhang J, Li M, Liu C, Zou W. Proteomic analysis of PKCγ-related proteins in the spinal cord of morphine-tolerant rats. PLoS One 2012; 7:e42068. [PMID: 22860055 PMCID: PMC3409149 DOI: 10.1371/journal.pone.0042068] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 07/02/2012] [Indexed: 12/16/2022] Open
Abstract
Background Morphine tolerance is a common drawback of chronic morphine exposure, hindering use of this drug. Studies have shown that PKCã may play a key role in the development of morphine tolerance, although the mechanisms are not fully known. Methodology/Principal Findings In a rat model of morphine tolerance, PKCã knockdown in the spinal cord was successfully carried out using RNA interference (RNAi) with lentiviral vector-mediated short hairpin RNA of PKCã (LV-shPKCã). Spinal cords (L4-L5) were obtained surgically from morphine-tolerant (MT) rats with and without PKCã knockdown, for comparative proteomic analysis. Total proteins from the spinal cords (L4-L5) were extracted and separated using two-dimensional gel electrophoresis (2DGE); 2D gel images were analyzed with PDQuest software. Seven differential gel-spots were observed with increased spot volume, and 18 spots observed with decreased spot volume. Among these, 13 differentially expressed proteins (DEPs) were identified with matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), comparing between MT rats with and without PKCã knockdown. The DEPs identified have roles in the cytoskeleton, as neurotrophic factors, in oxidative stress, in ion metabolism, in cell signaling, and as chaperones. Three DEPs (GFAP, FSCN and GDNF) were validated with Western blot analysis, confirming the DEP data. Furthermore, using immunohistochemical analysis, we reveal for the first time that FSCN is involved in the development of morphine tolerance. Conclusions/Significance These data cast light on the proteins associated with the PKCã activity during morphine tolerance, and hence may contribute to clarification of the mechanisms by which PKCã influences MT.
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Affiliation(s)
- Zongbin Song
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, China
| | - Qulian Guo
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, China
| | - Jie Zhang
- Department of Anesthesiology, the Maternal and Child Health Hospital of Hunan Province, Changsha, China
| | - Maoyu Li
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, China
| | - Chang Liu
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, China
| | - Wangyuan Zou
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, China
- * E-mail:
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Zhao YL, Chen SR, Chen H, Pan HL. Chronic opioid potentiates presynaptic but impairs postsynaptic N-methyl-D-aspartic acid receptor activity in spinal cords: implications for opioid hyperalgesia and tolerance. J Biol Chem 2012; 287:25073-85. [PMID: 22679016 DOI: 10.1074/jbc.m112.378737] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Opioids are the most effective analgesics for the treatment of moderate to severe pain. However, chronic opioid treatment can cause both hyperalgesia and analgesic tolerance, which limit their clinical efficacy. In this study, we determined the role of pre- and postsynaptic NMDA receptors (NMDARs) in controlling increased glutamatergic input in the spinal cord induced by chronic systemic morphine administration. Whole-cell voltage clamp recordings of excitatory postsynaptic currents (EPSCs) were performed on dorsal horn neurons in rat spinal cord slices. Chronic morphine significantly increased the amplitude of monosynaptic EPSCs evoked from the dorsal root and the frequency of spontaneous EPSCs, and these changes were largely attenuated by blocking NMDARs and by inhibiting PKC, but not PKA. Also, blocking NR2A- or NR2B-containing NMDARs significantly reduced the frequency of spontaneous EPSCs and the amplitude of evoked EPSCs in morphine-treated rats. Strikingly, morphine treatment largely decreased the amplitude of evoked NMDAR-EPSCs and NMDAR currents of dorsal horn neurons elicited by puff NMDA application. The reduction in postsynaptic NMDAR currents caused by morphine was prevented by resiniferatoxin pretreatment to ablate TRPV1-expressing primary afferents. Furthermore, intrathecal injection of the NMDAR antagonist significantly attenuated the development of analgesic tolerance and the reduction in nociceptive thresholds induced by chronic morphine. Collectively, our findings indicate that chronic opioid treatment potentiates presynaptic, but impairs postsynaptic, NMDAR activity in the spinal cord. PKC-mediated increases in NMDAR activity at nociceptive primary afferent terminals in the spinal cord contribute critically to the development of opioid hyperalgesia and analgesic tolerance.
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Affiliation(s)
- Yi-Lin Zhao
- Center for Pain and Neuroscience Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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5-hydroxytryptamine type 3 receptor modulates opioid-induced hyperalgesia and tolerance in mice. Anesthesiology 2011; 114:1180-9. [PMID: 21368652 DOI: 10.1097/aln.0b013e31820efb19] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Opioid-induced hyperalgesia (OIH) and tolerance are challenging maladaptations associated with opioids in managing pain. Recent genetic studies and the existing literature suggest the 5-hydroxytryptamine type 3 (5-HT3) receptor participates in these phenomena. The location of the relevant receptor populations and the interactions between the 5-HT3 system and other systems controlling OIH and tolerance have not been explored, however. We hypothesized that 5-HT3 receptors modulate OIH and tolerance, and that this modulation involves the control of expression of multiple neurotransmitter and receptor systems. METHODS C57BL/6 mice were exposed to a standardized 4-day morphine administration protocol. The 5-HT3 antagonist ondansetron was administered either during or after the conclusion of morphine administration. Mechanical testing was used to quantify OIH, and thermal tail-flick responses were used to measure morphine tolerance. In other experiments spinal cord and dorsal root ganglion tissues were harvested for analysis of messenger RNA concentrations by real-time polymerase chain reaction or immunochemistry analysis. RESULTS The results showed that (1) systemic or intrathecal injection of ondansetron significantly prevented and reversed OIH, but not local intraplantar injection; (2) systemic or intrathecal injection of ondansetron prevented and reversed tolerance; and (3) ondansetron blocked morphine-induced increases of multiple genes relevant to OIH and tolerance in dorsal root ganglion and spinal cord. CONCLUSIONS Morphine acts via a 5-HT3-dependent mechanism to support multiple maladaptations to the chronic administration of morphine. Furthermore, the use of 5-HT3 receptor antagonists may provide a new avenue to prevent or reverse OIH and tolerance associated with chronic opioid use.
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Song Z, Zou W, Liu C, Guo Q. Gene knockdown with lentiviral vector-mediated intrathecal RNA interference of protein kinase C gamma reverses chronic morphine tolerance in rats. J Gene Med 2010; 12:873-80. [PMID: 21105149 DOI: 10.1002/jgm.1514] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 08/14/2010] [Accepted: 10/10/2010] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Although morphine is a widely used opioid analgesic, morphine tolerance (MT) has limited the use of the drug because it creates the necessity for high doses. Protein kinase C (PKC), especially the PKCγ isoform, is considered to play a key role in the development of MT. Because RNA interference provides a powerful method for the investigation of gene function, and lentiviral delivery systems have been approved for human use, this present study examined rats tolerant to morphine to determine whether an intrathecal injection of a lentiviral vector of PKCγ short hairpin RNA (LV-shPKCγ) down-regulated the expression of the PKCγ gene and reversed MT. METHODS MT was induced by intrathecal morphine (10 µg b.i.d.) for six consecutive days. A lentiviral-mediated short hairpin RNA (shRNA) system was synthesized to deliver the PKCγ shRNAs to the spinal cord of the rats with MT. Mechanical and thermal paw withdrawal threshold were assessed to determine the analgesic effects of morphine. Expression of PKCγ mRNA and protein was determined by reverse transcriptase-polymerase chain reaction and western blotting analysis, respectively. RESULTS The chronic administration of morphine induced a stabilized analgesic tolerance. A single injection of LV-shPKCγ significantly reversed morphine antinociceptive tolerance. Compared to the control group, PKCγ mRNA and protein levels were dramatically down-regulated in the LV-shPKCγ group. CONCLUSIONS A single injection of LV-shPKCγ reversed MT by reducing the expression of PKCγ in the spinal cord. These findings indicate that the use of LV-shPKCγ might be a potential strategy for therapy in MT.
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Affiliation(s)
- Zongbin Song
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, China
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Abstract
Opioids remain the mainstay of treatment for severe pain, but the associated hyperalgesia and tolerance are significant impediments to achieving adequate pain relief with opioids. Here we show that in the spinal cord, brief application of the mu-opioid receptor agonist (D-Ala(2),N-Me-Phe(4),Gly-ol(5))-enkephalin (DAMGO) at 1 mum, but not at 1-10 nm, caused an initial decrease followed by a large and long-lasting increase in the amplitude of monosynaptic EPSCs evoked from the dorsal root in approximately 50% of lamina I and II neurons. However, postsynaptic dialysis of the G-protein inhibitor had no effect on DAMGO-induced initial inhibition and long-term potentiation (LTP) in either lamina I or II neurons. DAMGO-induced LTP was associated with an increase in the paired-pulse depression ratio. Furthermore, DAMGO application and washout induced an initial decrease followed by a persistent increase in the frequency of miniature EPSCs. Bath application, but not postsynaptic dialysis, of an NMDA receptor antagonist or a calcium chelator abolished DAMGO-induced LTP. Strikingly, ablation of TRPV1-expressing primary afferents not only eliminated DAMGO-induced LTP but also prolonged DAMGO-induced inhibition of the miniature and evoked EPSCs (i.e., long-term depression). Thus, our study strongly suggests that TRPV1-expressing primary afferents play a prominent role in opioid-induced presynaptic LTP, which challenges a previous report suggesting the postsynaptic nature of this opioid-induced LTP. This excitatory effect of opioids on primary afferents can counteract the inhibitory effect of opioids on synaptic transmission at the spinal level and is likely involved in opioid-induced hyperalgesia and tolerance.
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Liu DL, Wang WT, Xing JL, Hu SJ. Research progress in transient receptor potential vanilloid 1 of sensory nervous system. Neurosci Bull 2010; 25:221-7. [PMID: 19633705 DOI: 10.1007/s12264-009-0506-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The transient receptor potential vanilloid subfamily member 1 (TRPV1) is a protein mainly expressed in sensory neurons and fibers, such as in trigeminal ganglion and dorsal root ganglion, and has been indicated to be involved in several physiological and pathological processes. Studies on thermal activation have revealed that phosphorylation is involved in TRPV1 activation and 2 putative phosphorylation sites, Ser residues 502 (Ser-502) and Ser residues 800 (Ser-800), have been recently confirmed to possess the capability of resensitizing TRPV1. In addition to acidification, alkalization has also been proved to be a highly effective stimulator for TRPV1. TRPV1 could be regulated by various physical and chemical modulators, as well as the chronic pain. TRPV1 plays a crucial role in the transmission of pain signals, especially under inflammation and the neoplasm conditions, and it can also modulate nociceptive afferents by reinforcing morphine tolerance. The present review mainly focused on the structural and functional complexities of TRPV1, together with its activation and modulation by a wide variety of physical and chemical stimuli. Its pharmacological manipulation (sensitization/desensitization) and therapeutical targets were also discussed.
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Affiliation(s)
- Da-Lu Liu
- School of Stomatology, Institute of Neurosciences, Fourth Military Medical University, Xi'an 710033, China
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The role of mitogen-activated protein kinase (MAPK) in morphine tolerance and dependence. Mol Neurobiol 2009; 40:101-7. [PMID: 19468867 DOI: 10.1007/s12035-009-8074-z] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 05/12/2009] [Indexed: 01/18/2023]
Abstract
Despite the existence of a large body of information on the subject, the mechanisms of morphine tolerance and dependence are not yet fully understood. There is substantial evidence indicating that mitogen-activated protein kinase (MAPK), a family including extracellular signal-regulated protein kinase, p38 MAPK, and c-Jun N-terminal kinase, can be activated by chronic morphine treatment in the central and peripheral nervous systems and that application of a MAPK inhibitor reduces morphine tolerance and dependence. While the exact mechanism is not completely understood, recent evidence suggests that the activation of MAPK induced by long-term morphine exposure may participate in tolerance and dependence by regulating the downstream targets, such as calcitonin gene-related peptide, substance P, nitric oxide, transient receptor potential vanilloid 1, and proinflammatory cytokines. In this review, we focus on the current understanding of the role of MAPK signaling pathways in morphine tolerance and dependence.
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Abstract
This paper is the thirtieth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2007 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd.,Flushing, NY 11367, United States.
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TRPV1 receptor in expression of opioid-induced hyperalgesia. THE JOURNAL OF PAIN 2008; 10:243-52. [PMID: 18774343 DOI: 10.1016/j.jpain.2008.07.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Revised: 07/09/2008] [Accepted: 07/15/2008] [Indexed: 11/20/2022]
Abstract
UNLABELLED Opiates are currently the mainstay for treatment of moderate to severe pain. However, prolonged administration of opiates has been reported to elicit hyperalgesia in animals, and examples of opiate-induced hyperalgesia have been reported in humans as well. Despite the potential clinical significance of such opiate-induced actions, the mechanisms of opiate-induced hypersensitivity remain unknown. The transient receptor potential vanilloid1 (TRPV1) receptor, a molecular sensor of noxious heat, acts as an integrator of multiple forms of noxious stimuli and plays an important role in the development of inflammation-induced hyperalgesia. Because animals treated with opiates show thermal hyperalgesia, we examined the possible role of TRPV1 receptors in the development of morphine-induced hyperalgesia using TRPV1 wild-type (WT) and knock-out (KO) mice and with administration of a TRPV1 antagonist in mice and rats. Administration of morphine by subcutaneous implantation of morphine pellets elicited both thermal and tactile hypersensitivity in TRPV1 WT mice but not in TRPV1 KO mice. Moreover, oral administration of a TRPV1 antagonist reversed both thermal and tactile hypersensitivity induced by sustained morphine administration in mice and rats. Immunohistochemical analyses indicate that sustained morphine administration modestly increases TRPV1 labeling in the dorsal root ganglia. In addition, sustained morphine increased flinching and plasma extravasation after peripheral stimulation with capsaicin, suggesting an increase in TRPV1 receptor function in the periphery in morphine-treated animals. Collectively, our data indicate that the TRPV1 receptor is an essential peripheral mechanism in expression of morphine-induced hyperalgesia. PERSPECTIVE Opioid-induced hyperalgesia possibly limits the usefulness of opioids, emphasizing the value of alternative methods of pain control. We demonstrate that TRPV1 channels play an important role in peripheral mechanisms of opioid-induced hyperalgesia. Such information may lead to the discovery of analgesics lacking such adaptations and improving treatment of chronic pain.
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Zhou HY, Chen SR, Chen H, Pan HL. Sustained inhibition of neurotransmitter release from nontransient receptor potential vanilloid type 1-expressing primary afferents by mu-opioid receptor activation-enkephalin in the spinal cord. J Pharmacol Exp Ther 2008; 327:375-82. [PMID: 18669865 DOI: 10.1124/jpet.108.141226] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Removing transient receptor potential vanilloid type 1 (TRPV1)-expressing primary afferent neurons reduces presynaptic mu-opioid receptors but potentiates opioid analgesia. However, the sites and underlying cellular mechanisms for this paradoxical effect remain uncertain. In this study, we determined the presynaptic and postsynaptic effects of the mu-opioid receptor agonist [D-Ala(2),N-Me-Phe(4),Gly-ol(5)]-enkephalin (DAMGO) using whole-cell patch-clamp recordings of lamina II neurons in rat spinal cord slices. Treatment with the ultrapotent TRPV1 agonist resiniferotoxin (RTX) eliminated TRPV1-expressing dorsal root ganglion neurons and their central terminals in the spinal dorsal horn and significantly reduced the basal amplitude of glutamatergic excitatory postsynaptic currents (EPSCs) evoked from primary afferents. Although RTX treatment did not significantly alter the concentration-response effect of DAMGO on evoked monosynaptic and polysynaptic EPSCs, it causes a profound long-lasting inhibitory effect of DAMGO on evoked EPSCs. Subsequent naloxone treatment did not reverse the prolonged inhibitory effect of DAMGO on evoked EPSCs. Furthermore, brief application of DAMGO produced a sustained inhibition of miniature EPSCs in RTX-treated rats. However, the concentration response and the duration of the effects of DAMGO on G protein-coupled inwardly rectifying K+ currents in lamina II neurons were not significantly different between vehicle- and RTX-treated groups. These data suggest that stimulation of mu-opioid receptors on non-TRPV1 afferent terminals causes extended inhibition of neurotransmitter release to spinal dorsal horn neurons. The differential effect of mu-opioid receptor agonists on different phenotypes of primary afferents provides a cellular basis to explain why the analgesic action of opioids on mechanonociception is prolonged when TRPV1-expressing primary afferents are removed.
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Affiliation(s)
- Hong-Yi Zhou
- Department of Anesthesiology and Pain Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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Chen SR, Pan HL. Removing TRPV1-expressing primary afferent neurons potentiates the spinal analgesic effect of delta-opioid agonists on mechano-nociception. Neuropharmacology 2008; 55:215-22. [PMID: 18579164 DOI: 10.1016/j.neuropharm.2008.05.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Revised: 05/13/2008] [Accepted: 05/14/2008] [Indexed: 11/19/2022]
Abstract
Most delta-opioid receptors are located on the presynaptic terminals of primary afferent neurons in the spinal cord. However, their presence in different phenotypes of primary afferent neurons and their contribution to the analgesic effect of delta-opioid agonists are not fully known. Resiniferatoxin (RTX) is an ultra-potent transient receptor potential vanilloid type 1 channel (TRPV1) agonist and can selectively remove TRPV1-expressing primary afferent neurons. In this study, we determined the role of delta-opioid receptors expressed on TRPV1 sensory neurons in the antinociceptive effect of the delta-opioid receptor agonists [D-Pen(2),D-Pen(5)]-enkephalin and [D-Ala(2),Glu(4)]-deltorphin. Nociception was measured by testing the mechanical withdrawal threshold in the hindpaw of rats. Changes in the delta-opioid receptors were assessed using immunocytochemistry and the [(3)H]-naltrindole radioligand binding. In RTX-treated rats, the delta-opioid receptor on TRPV1-immunoreactive dorsal root ganglion neurons and afferent terminals in the spinal cord was diminished. RTX treatment also significantly reduced the maximal specific binding sites (31%) of the delta-opioid receptors in the dorsal spinal cord. Interestingly, intrathecal injection of [D-Pen(2),d-Pen(5)]-enkephalin or [D-Ala(2),Glu(4)]-deltorphin produced a large and prolonged increase in the nociceptive threshold in RTX-treated rats. These findings indicate that loss of TRPV1-expressing afferent neurons leads to a substantial reduction in presynaptic delta-opioid receptors in the spinal dorsal horn. However, the effect of delta-opioid agonists on mechano-nociception is paradoxically potentiated in the absence of TRPV1-expressing sensory neurons. This information is important to our understanding of the cellular sites and mechanisms underlying the spinal analgesic effect of delta-opioid agonists.
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MESH Headings
- Analgesics, Opioid/pharmacology
- Analysis of Variance
- Animals
- Behavior, Animal/drug effects
- Diterpenes/pharmacology
- Dose-Response Relationship, Drug
- Enkephalin, D-Penicillamine (2,5)-/pharmacology
- Gene Expression Regulation/drug effects
- Hyperalgesia/drug therapy
- Male
- Naltrexone/analogs & derivatives
- Naltrexone/metabolism
- Oligopeptides/pharmacology
- Pain Threshold/drug effects
- Protein Binding/drug effects
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/metabolism
- Sensory Receptor Cells/drug effects
- Sensory Receptor Cells/metabolism
- Spinal Cord/pathology
- TRPV Cation Channels/agonists
- TRPV Cation Channels/metabolism
- Tritium/metabolism
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Affiliation(s)
- Shao-Rui Chen
- Department of Anesthesiology and Pain Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030-4009, United States.
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Pan HL, Wu ZZ, Zhou HY, Chen SR, Zhang HM, Li DP. Modulation of pain transmission by G-protein-coupled receptors. Pharmacol Ther 2007; 117:141-61. [PMID: 17959251 DOI: 10.1016/j.pharmthera.2007.09.003] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 09/07/2007] [Indexed: 01/17/2023]
Abstract
The heterotrimeric G-protein-coupled receptors (GPCR) represent the largest and most diverse family of cell surface receptors and proteins. GPCR are widely distributed in the peripheral and central nervous systems and are one of the most important therapeutic targets in pain medicine. GPCR are present on the plasma membrane of neurons and their terminals along the nociceptive pathways and are closely associated with the modulation of pain transmission. GPCR that can produce analgesia upon activation include opioid, cannabinoid, alpha2-adrenergic, muscarinic acetylcholine, gamma-aminobutyric acidB (GABAB), groups II and III metabotropic glutamate, and somatostatin receptors. Recent studies have led to a better understanding of the role of these GPCR in the regulation of pain transmission. Here, we review the current knowledge about the cellular and molecular mechanisms that underlie the analgesic actions of GPCR agonists, with a focus on their effects on ion channels expressed on nociceptive sensory neurons and on synaptic transmission at the spinal cord level.
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Affiliation(s)
- Hui-Lin Pan
- Department of Anesthesiology and Pain Medicine, The University of Texas M.D. Anderson Cancer Center, Program in Neuroscience, The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77225, United States.
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Chen SR, Pan HM, Richardson TE, Pan HL. Potentiation of spinal alpha(2)-adrenoceptor analgesia in rats deficient in TRPV1-expressing afferent neurons. Neuropharmacology 2007; 52:1624-30. [PMID: 17482651 PMCID: PMC1948837 DOI: 10.1016/j.neuropharm.2007.03.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 02/15/2007] [Accepted: 03/15/2007] [Indexed: 02/05/2023]
Abstract
The alpha(2)-adrenoceptors (alpha(2)-ARs) are located on primary afferent terminals and on neurons in the spinal cord dorsal horn. However, their relative contribution to the analgesic effect of the alpha(2)-AR agonists is not known. In this study, we determined the role of certain presynaptic alpha(2)-ARs in the antinociceptive effect produced by intrathecal administration of the alpha(2)-AR agonist clonidine. TRPV1-expressing sensory neurons were removed by resiniferatoxin (RTX). The effect of intrathecal injection of clonidine was measured by testing the paw withdrawal response to noxious mechanical or heat stimuli. In RTX-treated rats, the alpha(2A)-AR-immunoreactivity co-expressed with TRPV1-expressing terminals in the spinal cord was eliminated. However, the alpha(2C)-AR-immunoreactivity in the spinal cord was little changed. Surprisingly, intrathecal administration of clonidine produced a much greater increase in the mechanical withdrawal threshold in RTX- than in vehicle-treated rats. The duration of the clonidine effect was also significantly increased in RTX-treated rats. Furthermore, in the vehicle-treated group, although intrathecal injection of clonidine produced a large increase in the thermal withdrawal latency, it only had a small and short-lasting effect on the mechanical withdrawal threshold. This study provides new information that the antinociceptive effect of spinally administered alpha(2)-AR agonists is largely modality-specific. Loss of TRPV1-expressing sensory neurons leads to a reduction in presynaptic alpha(2A)-ARs but paradoxically potentiates the effect of clonidine on mechano-nociception.
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Affiliation(s)
- Shao-Rui Chen
- Department of Anesthesiology and Pain Medicine The University of Texas M. D. Anderson Cancer Center Houston, TX 77030
| | - Hao-Min Pan
- Department of Anesthesiology and Pain Medicine The University of Texas M. D. Anderson Cancer Center Houston, TX 77030
| | - Timothy E. Richardson
- Department of Anesthesiology and Pain Medicine The University of Texas M. D. Anderson Cancer Center Houston, TX 77030
| | - Hui-Lin Pan
- Department of Anesthesiology and Pain Medicine The University of Texas M. D. Anderson Cancer Center Houston, TX 77030
- Program in Neuroscience The University of Texas Graduate School of Biomedical Sciences Houston, TX 77225
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