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Mandal A, Moneme C, Tewari BP, Goldstein AM, Sontheimer H, Cheng L, Moore SR, Levin D. A novel method for culturing enteric neurons generates neurospheres containing functional myenteric neuronal subtypes. J Neurosci Methods 2024; 407:110144. [PMID: 38670535 PMCID: PMC11144385 DOI: 10.1016/j.jneumeth.2024.110144] [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: 12/23/2023] [Revised: 03/04/2024] [Accepted: 04/20/2024] [Indexed: 04/28/2024]
Abstract
BACKGROUND The enteric nervous system (ENS) is comprised of neurons, glia, and neural progenitor cells that regulate essential gastrointestinal functions. Advances in high-efficiency enteric neuron culture would facilitate discoveries surrounding ENS regulatory processes, pathophysiology, and therapeutics. NEW METHOD Development of a simple, robust, one-step method to culture murine enteric neurospheres in a 3D matrix that supports neural growth and differentiation. RESULTS Myenteric plexus cells isolated from the entire length of adult murine small intestine formed ≥3000 neurospheres within 7 days. Matrigel-embedded neurospheres exhibited abundant neural stem and progenitor cells expressing Sox2, Sox10 and Msi1 by day 4. By day 5, neural progenitor cell marker Nestin appeared in the periphery of neurospheres prior to differentiation. Neurospheres produced extensive neurons and neurites, confirmed by Tubulin beta III, PGP9.5, HuD/C, and NeuN immunofluorescence, including neural subtypes Calretinin, ChAT, and nNOS following 8 days of differentiation. Individual neurons within and external to neurospheres generated depolarization induced action potentials which were inhibited in the presence of sodium channel blocker, Tetrodotoxin. Differentiated neurospheres also contained a limited number of glia and endothelial cells. COMPARISON WITH EXISTING METHODS This novel one-step neurosphere growth and differentiation culture system, in 3D format (in the presence of GDNF, EGF, and FGF2), allows for ∼2-fold increase in neurosphere count in the derivation of enteric neurons with measurable action potentials. CONCLUSION Our method describes a novel, robust 3D culture of electrophysiologically active enteric neurons from adult myenteric neural stem and progenitor cells.
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Affiliation(s)
- Arabinda Mandal
- Department of Surgery, University of Virginia, Charlottesville, VA, USA
| | - Chioma Moneme
- Department of Surgery, University of Virginia, Charlottesville, VA, USA
| | - Bhanu P Tewari
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Allan M Goldstein
- Department of Pediatric Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - Harald Sontheimer
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Lily Cheng
- Department of Surgery, University of Virginia, Charlottesville, VA, USA
| | - Sean R Moore
- Department of Pediatrics, Division of Pediatric Gastroenterology Hepatology, and Nutrition, University of Virginia, Charlottesville, VA, USA.
| | - Daniel Levin
- Department of Surgery, University of Virginia, Charlottesville, VA, USA.
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Muchhala KH, Kallurkar PS, Kang M, Koseli E, Poklis JL, Xu Q, Dewey WL, Fettweis JM, Jimenez NR, Akbarali HI. The role of morphine- and fentanyl-induced impairment of intestinal epithelial antibacterial activity in dysbiosis and its impact on the microbiota-gut-brain axis. FASEB J 2024; 38:e23603. [PMID: 38648368 PMCID: PMC11047137 DOI: 10.1096/fj.202301590rr] [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: 08/04/2023] [Revised: 03/22/2024] [Accepted: 03/26/2024] [Indexed: 04/25/2024]
Abstract
Recent evidence suggests that chronic exposure to opioid analgesics such as morphine disrupts the intestinal epithelial layer and causes intestinal dysbiosis. Depleting gut bacteria can preclude the development of tolerance to opioid-induced antinociception, suggesting an important role of the gut-brain axis in mediating opioid effects. The mechanism underlying opioid-induced dysbiosis, however, 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 or fentanyl exposure reduces the antimicrobial activity in the ileum, resulting in changes in the composition of bacteria. Fecal samples from morphine-treated mice had increased levels of Akkermansia muciniphila with a shift in the abundance ratio of Firmicutes and Bacteroidetes. Fecal microbial transplant (FMT) from morphine-naïve mice or oral supplementation with butyrate restored (a) the antimicrobial activity, (b) the expression of the antimicrobial peptide, Reg3γ, (c) prevented the increase in intestinal permeability and (d) prevented the development of antinociceptive tolerance in morphine-dependent mice. Improved epithelial barrier function with FMT or butyrate prevented the enrichment of the mucin-degrading A. muciniphila in morphine-dependent mice. These data implicate impairment of the antimicrobial activity of the intestinal epithelium as a mechanism by which opioids disrupt the microbiota-gut-brain axis.
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Affiliation(s)
- Karan H. Muchhala
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Prajkta S. Kallurkar
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Minho Kang
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Eda Koseli
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Justin L. Poklis
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Qingguo Xu
- Department of Pharmaceutics, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, United States
| | - William L. Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
| | - Jennifer M. Fettweis
- Department of Microbiology and Immunology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Nicole R. Jimenez
- Department of Microbiology and Immunology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Hamid I. Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, United States
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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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4
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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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Shi CJ, Lian JJ, Zhang BW, Cha JX, Hua QH, Pi XP, Hou YJ, Xie X, Zhang R. TGFβR-1/ALK5 inhibitor RepSox induces enteric glia-to-neuron transition and influences gastrointestinal mobility in adult mice. Acta Pharmacol Sin 2023; 44:92-104. [PMID: 35794374 DOI: 10.1038/s41401-022-00932-4] [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: 01/05/2022] [Accepted: 05/30/2022] [Indexed: 01/18/2023] Open
Abstract
Promoting adult neurogenesis in the enteric nervous system (ENS) may be a potential therapeutic approach to cure enteric neuropathies. Enteric glial cells (EGCs) are the most abundant glial cells in the ENS. Accumulating evidence suggests that EGCs can be a complementary source to supply new neurons during adult neurogenesis in the ENS. In the brain, astrocytes have been intensively studied for their neuronal conversion properties, and small molecules have been successfully used to induce the astrocyte-to-neuron transition. However, research on glia-to-neuron conversion in the ENS is still lacking. In this study, we used GFAP-Cre:Rosa-tdTomato mice to trace glia-to-neuron transdifferentiation in the ENS in vivo and in vitro. We showed that GFAP promoter-driven tdTomato exclusively labelled EGCs and was a suitable marker to trace EGCs and their progeny cells in the ENS of adult mice. Interestingly, we discovered that RepSox or other ALK5 inhibitors alone induced efficient transdifferentiation of EGCs into neurons in vitro. Knockdown of ALK5 further confirmed that the TGFβR-1/ALK5 signalling pathway played an essential role in the transition of EGCs to neurons. RepSox-induced neurons were Calbindin- and nNOS-positive and displayed typical neuronal electrophysiological properties. Finally, we showed that administration of RepSox (3, 10 mg· kg-1 ·d-1, i.g.) for 2 weeks significantly promoted the conversion of EGCs to neurons in the ENS and influenced gastrointestinal motility in adult mice. This study provides a method for efficiently converting adult mouse EGCs into neurons by small-molecule compounds, which might be a promising therapeutic strategy for gastrointestinal neuropathy.
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Affiliation(s)
- Chang-Jie Shi
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Jun-Jiang Lian
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Bo-Wen Zhang
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Jia-Xue Cha
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Qiu-Hong Hua
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Xiao-Ping Pi
- CAS Key Laboratory of Receptor Research, the National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Yu-Jun Hou
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Xin Xie
- CAS Key Laboratory of Receptor Research, the National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Ru Zhang
- Shanghai Key Laboratory of Signaling and Disease Research, Laboratory of Receptor-based Bio-medicine, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China.
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Liao K, Niu F, Hu G, Buch S. Morphine-mediated release of astrocyte-derived extracellular vesicle miR-23a induces loss of pericyte coverage at the blood-brain barrier: Implications for neuroinflammation. Front Cell Dev Biol 2022; 10:984375. [PMID: 36478740 PMCID: PMC9720401 DOI: 10.3389/fcell.2022.984375] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 11/07/2022] [Indexed: 08/08/2023] Open
Abstract
Opioids such as morphine are the most potent and efficacious drugs currently available for pain management. Paradoxically, opioids have also been implicated in inducing neuroinflammation and associated neurocognitive decline. Pericytes, a critical component of the neurovascular unit (NVU), are centrally positioned between endothelial cells and astrocytes, maintaining function of the blood-brain barrier (BBB) nd regulating neuroinflammation by controlling monocyte influx under various pathological conditions. The role of pericytes in morphine-mediated neuroinflammation however, has received less attention, especially in the context of how pericytes crosstalk with other central nervous system (CNS) cells. The current study was undertaken to examine the effect of miRNAs released from morphine-stimulated human primary astrocyte-derived extracellular vesicles (morphine-ADEVs) in mediating pericyte loss at the blood-brain barrier, leading, in turn, to increased influx of peripheral monocytes. Our findings suggest that the heterogeneous nuclear ribonucleoprotein complex A2/B1 (hnRNP A2/B1) plays role in morphine-mediated upregulation and release of miR-23a in ADEVs, and through action of morphine via mu opioid receptor.We further demonstrated that miR-23a in morphine-ADEVs could be taken up by pericytes, resulting in downregulation of PTEN expression, ultimately leading to increased pericyte migration. Furthermore, both overexpression of PTEN and blocking the miR-23a target site at PTEN 3UTR (by transfecting miR-23a-PTEN target protector), attenuated morphine-ADEV-mediated pericyte migration. We also demonstrated that in the microvessels isolated from morphine-administered mice, there were fewer PDGFβR + pericytes co-localizing with CD31+ brain endothelial cells compared with those from saline mice. In line with these findings, we also observed increased loss of pericytes and a concomitantly increased influx of monocytes in the brains of morphine-administered pericyte-labeled NG2-DsRed mice compared with saline mice. In conclusion, our findings indicate morphine-ADEVs mediated loss of pericyte coverage at the brain endothelium, thereby increasing the influx of peripheral monocytes in the central nervous system, leading to neuroinflammation.
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Affiliation(s)
- Ke Liao
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Fang Niu
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
| | - Guoku Hu
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
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7
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Muchhala KH, Koseli E, Gade AR, Woods K, Minai S, Kang M, McQuiston AR, Dewey WL, Akbarali HI. Chronic Morphine Induces IL-18 in Ileum Myenteric Plexus Neurons Through Mu-opioid Receptor Activation in Cholinergic and VIPergic Neurons. J Neuroimmune Pharmacol 2022; 17:111-130. [PMID: 35106734 PMCID: PMC9343479 DOI: 10.1007/s11481-021-10050-3] [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: 12/02/2021] [Accepted: 12/26/2021] [Indexed: 12/29/2022]
Abstract
The gastrointestinal epithelium is critical for maintaining a symbiotic relationship with commensal microbiota. Chronic morphine exposure can compromise the gut epithelial barrier in mice and lead to dysbiosis. Recently, studies have implicated morphine-induced dysbiosis in the mechanism of antinociceptive tolerance and reward, suggesting the presence of a gut-brain axis in the pharmacological effects of morphine. However, the mechanism(s) underlying morphine-induced changes in the gut microbiome remains unclear. The pro-inflammatory cytokine, Interleukin-18 (IL-18), released by enteric neurons can modulate gut barrier function. Therefore, in the present study we investigated the effect of morphine on IL-18 expression in the mouse ileum. We observed that chronic morphine exposure in vivo induces IL-18 expression in the ileum myenteric plexus that is attenuated by naloxone. Given that mu-opioid receptors (MORs) are mainly expressed in enteric neurons, we also characterized morphine effects on the excitability of cholinergic (excitatory) and vasoactive intestinal peptide (VIP)-expressing (inhibitory) myenteric neurons. We found fundamental differences in the electrical properties of cholinergic and VIP neurons such that VIP neurons are more excitable than cholinergic neurons. Furthermore, MORs were primarily expressed in cholinergic neurons, although a subset of VIP neurons also expressed MORs and responded to morphine in electrophysiology experiments. In conclusion, these data show that morphine increases IL-18 in ileum myenteric plexus neurons via activation of MORs in a subset of cholinergic and VIP neurons. Thus, understanding the neurochemistry and electrophysiology of MOR-expressing enteric neurons can help to delineate mechanisms by which morphine perturbs the gut barrier.
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Affiliation(s)
- Karan H Muchhala
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1112 E. Clay Street, Richmond, VA 23298
| | - Eda Koseli
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1112 E. Clay Street, Richmond, VA 23298
| | - Aravind R Gade
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1112 E. Clay Street, Richmond, VA 23298
| | - Kareem Woods
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1112 E. Clay Street, Richmond, VA 23298
| | - Suha Minai
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1112 E. Clay Street, Richmond, VA 23298
| | - Minho Kang
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1112 E. Clay Street, Richmond, VA 23298
| | - A Rory McQuiston
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University, 1101 E. Marshall Street, Richmond VA 23298
| | - William L Dewey
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1112 E. Clay Street, Richmond, VA 23298
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, 1112 E. Clay Street, Richmond, VA 23298,Corresponding Author:
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Dodu JC, Moncayo RK, Damaj MI, Schlosburg JE, Akbarali HI, O'Brien LD, Kendall DA, Wu Z, Lu D, Lichtman AH. The Cannabinoid Receptor Type 1 Positive Allosteric Modulator ZCZ011 Attenuates Naloxone-Precipitated Diarrhea and Weight Loss in Oxycodone-Dependent Mice. J Pharmacol Exp Ther 2022; 380:1-14. [PMID: 34625464 PMCID: PMC8969135 DOI: 10.1124/jpet.121.000723] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 10/01/2021] [Indexed: 01/03/2023] Open
Abstract
Opioid use disorder reflects a major public health crisis of morbidity and mortality in which opioid withdrawal often contributes to continued use. However, current medications that treat opioid withdrawal symptoms are limited by their abuse liability or lack of efficacy. Although cannabinoid 1 (CB1) receptor agonists, including Δ9-tetrahydrocannabinol, ameliorate opioid withdrawal in both clinical and preclinical studies of opioid dependence, this strategy elicits cannabimimetic side effects as well as tolerance and dependence after repeated administration. Alternatively, CB1 receptor positive allosteric modulators (PAMs) enhance CB1 receptor signaling and show efficacy in rodent models of pain and cannabinoid dependence but lack cannabimimetic side effects. We hypothesize that the CB1 receptor PAM ZCZ011 attenuates naloxone-precipitated withdrawal signs in opioid-dependent mice. Accordingly, male and female mice given an escalating dosing regimen of oxycodone, a widely prescribed opioid, and challenged with naloxone displayed withdrawal signs that included diarrhea, weight loss, jumping, paw flutters, and head shakes. ZCZ011 fully attenuated naloxone-precipitated withdrawal-induced diarrhea and weight loss and reduced paw flutters by approximately half, but its effects on head shakes were unreliable, and it did not affect jumping behavior. The antidiarrheal and anti-weight loss effects of ZCZ0111 were reversed by a CB1 not a cannabinoid receptor type 2 receptor antagonist and were absent in CB1 (-/-) mice, suggesting a necessary role of CB1 receptors. Collectively, these results indicate that ZCZ011 completely blocked naloxone-precipitated diarrhea and weight loss in oxycodone-dependent mice and suggest that CB1 receptor PAMs may offer a novel strategy to treat opioid dependence. SIGNIFICANCE STATEMENT: Opioid use disorder represents a serious public health crisis in which current medications used to treat withdrawal symptoms are limited by abuse liability and side effects. The CB1 receptor positive allosteric modulator (PAM) ZCZ011, which lacks overt cannabimimetic behavioral effects, ameliorated naloxone-precipitated withdrawal signs through a CB1 receptor mechanism of action in a mouse model of oxycodone dependence. These results suggest that CB1 receptor PAMs may represent a viable strategy to treat opioid withdrawal.
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Affiliation(s)
- Julien C Dodu
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
| | - Rebecca K Moncayo
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
| | - M Imad Damaj
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
| | - Joel E Schlosburg
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
| | - Hamid I Akbarali
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
| | - Lesley D O'Brien
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
| | - Debra A Kendall
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
| | - Zhixing Wu
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
| | - Dai Lu
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
| | - Aron H Lichtman
- Department of Pharmacology & Toxicology (J.C.D., R.K.M., M.I.D., J.E.S., H.I.A., L.D.O., A.H.L.), and Department of Medicinal Chemistry (A.H.L.), Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutical Sciences, University of Connecticut, Mansfield, Connecticut (D.A.K.); and Department of Pharmaceutical Sciences, Texas A&M, College Station, Texas (Z.W., D.L.)
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Paul AK, Smith CM, Rahmatullah M, Nissapatorn V, Wilairatana P, Spetea M, Gueven N, Dietis N. Opioid Analgesia and Opioid-Induced Adverse Effects: A Review. Pharmaceuticals (Basel) 2021; 14:1091. [PMID: 34832873 PMCID: PMC8620360 DOI: 10.3390/ph14111091] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 01/08/2023] Open
Abstract
Opioids are widely used as therapeutic agents against moderate to severe acute and chronic pain. Still, these classes of analgesic drugs have many potential limitations as they induce analgesic tolerance, addiction and numerous behavioural adverse effects that often result in patient non-compliance. As opium and opioids have been traditionally used as painkillers, the exact mechanisms of their adverse reactions over repeated use are multifactorial and not fully understood. Older adults suffer from cancer and non-cancer chronic pain more than younger adults, due to the physiological changes related to ageing and their reduced metabolic capabilities and thus show an increased number of adverse reactions to opioid drugs. All clinically used opioids are μ-opioid receptor agonists, and the major adverse effects are directly or potentially connected to this receptor. Multifunctional opioid ligands or peripherally restricted opioids may elicit fewer adverse effects, as shown in preclinical studies, but these results need reproducibility from further extensive clinical trials. The current review aims to overview various mechanisms involved in the adverse effects induced by opioids, to provide a better understanding of the underlying pathophysiology and, ultimately, to help develop an effective therapeutic strategy to better manage pain.
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Affiliation(s)
- Alok K. Paul
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7001, Australia;
| | - Craig M. Smith
- School of Medicine, Institute for Mental and Physical Health and Clinical Translation, Deakin University, Geelong, VIC 3216, Australia;
| | - Mohammed Rahmatullah
- Department of Biotechnology & Genetic Engineering, University of Development Alternative, Dhanmondi, Dhaka 1207, Bangladesh;
| | - Veeranoot Nissapatorn
- School of Allied Health Sciences, World Union for Herbal Drug Discovery (WUHeDD) and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Nakhon Si Thammarat 80160, Thailand;
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Mariana Spetea
- Department of Pharmaceutical Chemistry, Institute of Pharmacy and Center for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria;
| | - Nuri Gueven
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7001, Australia;
| | - Nikolas Dietis
- Medical School, University of Cyprus, Nicosia 1678, Cyprus;
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10
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Lucerne KE, Osman A, Meckel KR, Kiraly DD. Contributions of neuroimmune and gut-brain signaling to vulnerability of developing substance use disorders. Neuropharmacology 2021; 192:108598. [PMID: 33965398 DOI: 10.1016/j.neuropharm.2021.108598] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 03/19/2021] [Accepted: 05/03/2021] [Indexed: 02/06/2023]
Abstract
Epidemiology and clinical research indicate that only a subset of people who are exposed to drugs of abuse will go on to develop a substance use disorder. Numerous factors impact individual susceptibility to developing a substance use disorder, including intrinsic biological factors, environmental factors, and interpersonal/social factors. Given the extensive morbidity and mortality that is wrought as a consequence of substance use disorders, a substantial body of research has focused on understanding the risk factors that mediate the shift from initial drug use to pathological drug use. Understanding these risk factors provides a clear path for the development of risk mitigation strategies to help reduce the burden of substance use disorders in the population. Here we will review the rapidly growing body of literature that examines the importance of interactions between the peripheral immune system, the gut microbiome, and the central nervous system (CNS) in mediating the transition to pathological drug use. While these systems had long been viewed as distinct, there is growing evidence that there is bidirectional communication between both the immune system and the gut microbiome that drive changes in neural and behavioral plasticity relevant to substance use disorders. Further, both of these systems are highly sensitive to environmental perturbations and are implicated in numerous neuropsychiatric conditions. While the field of study examining these interactions in substance use disorders is in its relative infancy, clarifying the relationship between gut-immune-brain signaling and substance use disorders has potential to improve our understanding of individual propensity to developing addiction and yield important insight into potential treatment options.
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Affiliation(s)
- Kelsey E Lucerne
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Aya Osman
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Katherine R Meckel
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Drew D Kiraly
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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11
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van den Hoogen NJ, de Geus TJ, Patijn J, Tibboel D, Joosten EA. Methadone effectively attenuates acute and long-term consequences of neonatal repetitive procedural pain in a rat model. Pediatr Res 2021; 89:1681-1686. [PMID: 33504957 DOI: 10.1038/s41390-020-01353-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 11/02/2020] [Accepted: 12/17/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Painful procedures in early life cause acute pain and can alter pain processing at a spinal level lasting into adulthood. Current methods of analgesia seem unable to prevent both acute and long-term hypersensitivity associated with neonatal pain. The current study aims to prevent acute and long-term hypersensitivity associated with neonatal procedural pain using methadone analgesia in rat pups. METHODS Sprague-Dawley rat pups received either methadone (1 mg/kg) or saline prior to repetitive needle pricks into the left hind paw from the day of birth (postnatal day (P)0) to P7. Control littermates received a tactile stimulus. Mechanical sensitivity was assessed during the neonatal period (P0-P7), from weaning to adulthood (3-7 weeks) and following surgical re-injury of the same dermatome in adulthood. RESULTS Methadone administration completely reversed acute hypersensitivity from P0 to P7. In addition, neonatal methadone analgesia prevented prolonged hypersensitivity after re-injury in adulthood, without affecting sensitivity from weaning to adulthood. CONCLUSIONS The current study shows that neonatal methadone analgesia can attenuate acute as well as long-term hypersensitivity associated with neonatal procedural pain in a rat model. IMPACT Methadone treatment attenuates acute and long-term hypersensitivity associated with neonatal pain in a rat model. Clinical effectiveness studies are urgently warranted to assess acute and long-term analgesic effectivity of methadone.
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Affiliation(s)
- Nynke J van den Hoogen
- Department of Anaesthesiology and Pain Management, Maastricht University Medical Centre, Maastricht, The Netherlands. .,Department of Translational Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands. .,Hotchkiss Brain Institute, University of Calgary, Calgary, Canada.
| | - Thomas J de Geus
- Department of Anaesthesiology and Pain Management, Maastricht University Medical Centre, Maastricht, The Netherlands.,Department of Translational Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Jacob Patijn
- Department of Anaesthesiology and Pain Management, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Dick Tibboel
- Intensive Care and Department of Paediatric Surgery, Erasmus Medical Centre - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Elbert A Joosten
- Department of Anaesthesiology and Pain Management, Maastricht University Medical Centre, Maastricht, The Netherlands.,Department of Translational Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
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12
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Wu W, Yao H, Dwivedi I, Negraes PD, Zhao HW, Wang J, Trujillo CA, Muotri AR, Haddad GG. Methadone Suppresses Neuronal Function and Maturation in Human Cortical Organoids. Front Neurosci 2020; 14:593248. [PMID: 33328864 PMCID: PMC7719724 DOI: 10.3389/fnins.2020.593248] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/20/2020] [Indexed: 12/02/2022] Open
Abstract
Accumulating evidence has suggested that prenatal exposure to methadone causes multiple adverse effects on human brain development. Methadone not only suppresses fetal neurobehavior and alters neural maturation, but also leads to long-term neurological impairment. Due to logistical and ethical issues of accessing human fetal tissue, the effect of methadone on brain development and its underlying mechanisms have not been investigated adequately and are therefore not fully understood. Here, we use human cortical organoids which resemble fetal brain development to examine the effect of methadone on neuronal function and maturation during early development. During development, cortical organoids that are exposed to clinically relevant concentrations of methadone exhibited suppressed maturation of neuronal function. For example, organoids developed from 12th week till 24th week have an about 7-fold increase in AP firing frequency, but only half and a third of this increase was found in organoids exposed to 1 and 10 μM methadone, respectively. We further demonstrated substantial increases in INa (4.5-fold) and IKD (10.8-fold), and continued shifts of Na+ channel activation and inactivation during normal organoid development. Methadone-induced suppression of neuronal function was attributed to the attenuated increase in the densities of INa and IKD and the reduced shift of Na+ channel gating properties. Since normal neuronal electrophysiology and ion channel function are critical for regulating brain development, we believe that the effect of prolonged methadone exposure contributes to the delayed maturation, development fetal brain and potentially for longer term neurologic deficits.
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Affiliation(s)
- Wei Wu
- Department of Pediatrics, School of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Hang Yao
- Department of Pediatrics, School of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Ila Dwivedi
- Department of Pediatrics, School of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Priscilla D Negraes
- Department of Cellular and Molecular Medicine, Stem Cell Program, Center for Academic Research and Training in Anthropogeny, Kavli Institute for Brain and Mind, University of California, San Diego, San Diego, CA, United States
| | - Helen W Zhao
- Department of Pediatrics, School of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Juan Wang
- Department of Pediatrics, School of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Cleber A Trujillo
- Department of Cellular and Molecular Medicine, Stem Cell Program, Center for Academic Research and Training in Anthropogeny, Kavli Institute for Brain and Mind, University of California, San Diego, San Diego, CA, United States
| | - Alysson R Muotri
- Department of Pediatrics, School of Medicine, University of California, San Diego, San Diego, CA, United States.,Department of Cellular and Molecular Medicine, Stem Cell Program, Center for Academic Research and Training in Anthropogeny, Kavli Institute for Brain and Mind, University of California, San Diego, San Diego, CA, United States
| | - Gabriel G Haddad
- Department of Pediatrics, School of Medicine, University of California, San Diego, San Diego, CA, United States.,Department of Neurosciences, School of Medicine, University of California, San Diego, San Diego, CA, United States.,Rady Children's Hospital, San Diego, CA, United States
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13
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Plakhova VB, Penniyaynen VA, Rogachevskii IV, Podzorova SA, Khalisov MM, Ankudinov AV, Krylov BV. Dual mechanism of modulation of Na V1.8 sodium channels by ouabain. Can J Physiol Pharmacol 2020; 98:785-802. [PMID: 32687732 DOI: 10.1139/cjpp-2020-0197] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the primary sensory neuron, ouabain activates the dual mechanism that modulates the functional activity of NaV1.8 channels. Ouabain at endogenous concentrations (EO) triggers two different signaling cascades, in which the Na,K-ATPase/Src complex is the EO target and the signal transducer. The fast EO effect is based on modulation of the NaV1.8 channel activation gating device. EO triggers the tangential signaling cascade along the neuron membrane from Na,K-ATPase to the NaV1.8 channel. It evokes a decrease in effective charge transfer of the NaV1.8 channel activation gating device. Intracellular application of PP2, an inhibitor of Src kinase, completely eliminated the effect of EO, thus indicating the absence of direct EO binding to the NaV1.8 channel. The delayed EO effect probably controls the density of NaV1.8 channels in the neuron membrane. EO triggers the downstream signaling cascade to the neuron genome, which should result in a delayed decrease in the NaV1.8 channels' density. PKC and p38 MAPK are involved in this pathway. Identification of the dual mechanism of the strong EO effect on NaV1.8 channels makes it possible to suggest that application of EO to the primary sensory neuron membrane should result in a potent antinociceptive effect at the organismal level.
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Affiliation(s)
- Vera B Plakhova
- Pavlov Institute of Physiology of the Russian Academy of Sciences, 6 Makarova Emb., 199034, Saint Petersburg, Russia
| | - Valentina A Penniyaynen
- Pavlov Institute of Physiology of the Russian Academy of Sciences, 6 Makarova Emb., 199034, Saint Petersburg, Russia
| | - Ilia V Rogachevskii
- Pavlov Institute of Physiology of the Russian Academy of Sciences, 6 Makarova Emb., 199034, Saint Petersburg, Russia
| | - Svetlana A Podzorova
- Pavlov Institute of Physiology of the Russian Academy of Sciences, 6 Makarova Emb., 199034, Saint Petersburg, Russia
| | - Maksim M Khalisov
- Pavlov Institute of Physiology of the Russian Academy of Sciences, 6 Makarova Emb., 199034, Saint Petersburg, Russia
| | - Alexander V Ankudinov
- Ioffe Physical Technical Institute, Russian Academy of Sciences, 26 Polytekhnicheskaya str., 194021, Saint Petersburg, Russia
| | - Boris V Krylov
- Pavlov Institute of Physiology of the Russian Academy of Sciences, 6 Makarova Emb., 199034, Saint Petersburg, Russia
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14
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Mischel RA, Muchhala KH, Dewey WL, Akbarali HI. The "Culture" of Pain Control: A Review of Opioid-Induced Dysbiosis (OID) in Antinociceptive Tolerance. THE JOURNAL OF PAIN 2020; 21:751-762. [PMID: 31841668 PMCID: PMC7286790 DOI: 10.1016/j.jpain.2019.11.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/15/2022]
Abstract
It is increasingly recognized that chronic opioid use leads to maladaptive changes in the composition and localization of gut bacteria. Recently, this "opioid-induced dysbiosis" (OID) has been linked to antinociceptive tolerance development in preclinical models and may therefore identify promising targets for new opioid-sparing strategies. Such developments are critical to curb dose escalations in the clinical setting and combat the ongoing opioid epidemic. In this article, we review the existing literature that pertains to OID, including the current evidence regarding its qualitative nature, influence on antinociceptive tolerance, and future prospects. PERSPECTIVE: This article reviews the current literature on OID of gut bacteria, including its qualitative nature, influence on antinociceptive tolerance, and future prospects. This work may help identify targets for new opioid-sparing strategies.
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Affiliation(s)
- Ryan A Mischel
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Karan H Muchhala
- 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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15
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Grim TW, Acevedo-Canabal A, Bohn LM. Toward Directing Opioid Receptor Signaling to Refine Opioid Therapeutics. Biol Psychiatry 2020; 87:15-21. [PMID: 31806082 PMCID: PMC6919561 DOI: 10.1016/j.biopsych.2019.10.020] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 10/23/2019] [Accepted: 10/24/2019] [Indexed: 12/22/2022]
Abstract
The mu opioid receptor (MOR) is a diversely regulated target for the alleviation of pain in the clinical setting. However, untoward side effects such as tolerance, dependence, respiratory suppression, constipation, and abuse liability detract from the general activation of these receptors. Studies in genetically modified rodent models suggest that activating G protein signaling pathways while avoiding phosphorylation of the receptor or recruitment of β-arrestin scaffolding proteins could preserve the analgesic properties of MOR agonists while avoiding certain side effects. With the development of novel MOR "biased" agonists, which lead to preferential activation of G protein pathways over receptor phosphorylation, internalization, or interaction with other effectors, this hypothesis can be tested in a native, physiological setting. Overall, it is clear that the MOR is not a simple on-off switch and that the diverse means by which the receptor can be regulated may present an opportunity to refine therapeutics for the treatment of pain.
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Affiliation(s)
- Travis W Grim
- Departments of Molecular Medicine and Neuroscience, the Scripps Research Institute, Jupiter, Florida
| | - Agnes Acevedo-Canabal
- Departments of Molecular Medicine and Neuroscience, the Scripps Research Institute, Jupiter, Florida
| | - Laura M Bohn
- Departments of Molecular Medicine and Neuroscience, the Scripps Research Institute, Jupiter, Florida.
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16
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DiCello JJ, Carbone SE, Saito A, Rajasekhar P, Ceredig RA, Pham V, Valant C, Christopoulos A, Veldhuis NA, Canals M, Massotte D, Poole DP. Mu and Delta Opioid Receptors Are Coexpressed and Functionally Interact in the Enteric Nervous System of the Mouse Colon. Cell Mol Gastroenterol Hepatol 2019; 9:465-483. [PMID: 31759144 PMCID: PMC7036548 DOI: 10.1016/j.jcmgh.2019.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 11/13/2019] [Accepted: 11/13/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Functional interactions between the mu opioid receptor (MOR) and delta opioid receptor (DOR) represent a potential target for novel analgesics and may drive the effects of the clinically approved drug eluxadoline for the treatment of diarrhea-predominant irritable bowel syndrome. Although the enteric nervous system (ENS) is a likely site of action, the coexpression and potential interaction between MOR and DOR in the ENS are largely undefined. In the present study, we have characterized the distribution of MOR in the mouse ENS and examined MOR-DOR interactions by using pharmacologic and cell biology techniques. METHODS MOR and DOR expression was defined by using MORmCherry and MORmCherry-DOR-eGFP knockin mice. MOR-DOR interactions were assessed by using DOR-eGFP internalization assays and by pharmacologic analysis of neurogenic contractions of the colon. RESULTS Although MOR was expressed by approximately half of all myenteric neurons, MOR-positive submucosal neurons were rarely observed. There was extensive overlap between MOR and DOR in both excitatory and inhibitory pathways involved in the coordination of intestinal motility. MOR and DOR can functionally interact, as shown through heterologous desensitization of MOR-dependent responses by DOR agonists. Functional evidence suggests that MOR and DOR may not exist as heteromers in the ENS. Pharmacologic studies show no evidence of cooperativity between MOR and DOR. DOR internalizes independently of MOR in myenteric neurons, and MOR-evoked contractions are unaffected by the sequestration of DOR. CONCLUSIONS Collectively, these findings demonstrate that although MOR and DOR are coexpressed in the ENS and functionally interact, they are unlikely to exist as heteromers under physiological conditions.
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MESH Headings
- Analgesics, Opioid/pharmacology
- Animals
- Benzamides/pharmacology
- CHO Cells
- Colon/metabolism
- Cricetulus
- Enteric Nervous System/drug effects
- Enteric Nervous System/metabolism
- Gastrointestinal Motility/drug effects
- Gastrointestinal Motility/physiology
- Gene Knock-In Techniques
- Genes, Reporter/genetics
- Green Fluorescent Proteins/genetics
- Humans
- Luminescent Proteins/genetics
- Mice
- Morphine/pharmacology
- Piperazines/pharmacology
- Piperidines/pharmacology
- Protein Multimerization/physiology
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/genetics
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/metabolism
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Red Fluorescent Protein
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Affiliation(s)
- Jesse J DiCello
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia; Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, Melbourne, VIC, Australia
| | - Simona E Carbone
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia; Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, Melbourne, VIC, Australia
| | - Ayame Saito
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia; Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, Melbourne, VIC, Australia
| | - Pradeep Rajasekhar
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia; Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, Melbourne, VIC, Australia
| | - Rhian A Ceredig
- Centre de la Recherche Nationale Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Vi Pham
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Celine Valant
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Nicholas A Veldhuis
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia; Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, Melbourne, VIC, Australia
| | - Meritxell Canals
- Division of Physiology, Pharmacology and Neuroscience, Queen's Medical Centre, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, United Kingdom
| | - Dominique Massotte
- Centre de la Recherche Nationale Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Daniel P Poole
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia; Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, Melbourne, VIC, Australia; Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC, Australia.
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17
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Liu Y, Hsiao H, Wang JC, Liu Y, Wu S. Effectiveness of nalbuphine, a κ‐opioid receptor agonist and μ‐opioid receptor antagonist, in the inhibition ofINa,IK(M), andIK(erg)unlinked to interaction with opioid receptors. Drug Dev Res 2019; 80:846-856. [DOI: 10.1002/ddr.21568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/25/2019] [Accepted: 06/30/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Yuan‐Yuarn Liu
- Division of Trauma, Department of EmergencyKaohsiung Veterans General Hospital Kaohsiung City Taiwan
| | - Hung‐Tsung Hsiao
- Department of Anesthesiology, National Cheng Kung University Hospital, College of MedicineNational Cheng Kung University Tainan City Taiwan
| | - Jeffery C.‐F. Wang
- Department of Anesthesiology, National Cheng Kung University Hospital, College of MedicineNational Cheng Kung University Tainan City Taiwan
| | - Yen‐Chin Liu
- Department of Anesthesiology, National Cheng Kung University Hospital, College of MedicineNational Cheng Kung University Tainan City Taiwan
| | - Sheng‐Nan Wu
- Institute of Basic Medical SciencesNational Cheng Kung University Medical College Tainan City Taiwan
- Department of PhysiologyNational Cheng Kung University Medical College Tainan City Taiwan
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18
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A potential role for the gut microbiome in substance use disorders. Psychopharmacology (Berl) 2019; 236:1513-1530. [PMID: 30982128 PMCID: PMC6599482 DOI: 10.1007/s00213-019-05232-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 03/19/2019] [Indexed: 02/06/2023]
Abstract
Pathological substance use disorders represent a major public health crisis with limited effective treatment options. While much work has been done to understand the neuronal signaling networks and intracellular signaling cascades associated with prolonged drug use, these studies have yielded few successful treatment options for substance use disorders. In recent years, there has been a growing interest to explore interactions between the peripheral immune system, the gut microbiome, and the CNS. In this review, we will present a summary of existing evidence, suggesting a potential role for gut dysbiosis in the pathogenesis of substance use disorders. Clinical evidence of gut dysbiosis in human subjects with substance use disorder and preclinical evidence of gut dysbiosis in animal models of drug addiction are discussed in detail. Additionally, we examine how changes in the gut microbiome and its metabolites may not only be a consequence of substance use disorders but may in fact play a role in mediating behavioral response to drugs of abuse. While much work still needs to be done, understanding the interplay of gut microbiome in substance use disorders may offer a promising avenue for future therapeutic development.
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19
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Mischel RA, Dewey WL, Akbarali HI. Tolerance to Morphine-Induced Inhibition of TTX-R Sodium Channels in Dorsal Root Ganglia Neurons Is Modulated by Gut-Derived Mediators. iScience 2018; 2:193-209. [PMID: 29888757 PMCID: PMC5993194 DOI: 10.1016/j.isci.2018.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/06/2018] [Accepted: 02/15/2018] [Indexed: 01/10/2023] Open
Abstract
In the clinical setting, analgesic tolerance is a primary driver of diminished pain control and opioid dose escalations. Integral to this process are primary afferent sensory neurons, the first-order components of nociceptive sensation. Here, we characterize the factors modulating morphine action and tolerance in mouse small diameter dorsal root ganglia (DRG) neurons. We demonstrate that acute morphine inactivates tetrodotoxin-resistant (TTX-R) Na+ channels in these cells. Chronic exposure resulted in tolerance to this effect, which was prevented by treatment with oral vancomycin. Using colonic supernatants, we further show that mediators in the gut microenvironment of mice with chronic morphine exposure can induce tolerance and hyperexcitability in naive DRG neurons. Tolerance (but not hyperexcitability) in this paradigm was mitigated by oral vancomycin treatment. These findings collectively suggest that gastrointestinal microbiota modulate the development of morphine tolerance (but not hyperexcitability) in nociceptive primary afferent neurons, through a mechanism involving TTX-R Na+ channels.
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Affiliation(s)
- Ryan A Mischel
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 E. Clay St., McGuire Hall 100D, Richmond, VA 23298, USA
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 E. Clay St., McGuire Hall 100D, Richmond, VA 23298, USA
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 E. Clay St., McGuire Hall 100D, Richmond, VA 23298, USA.
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20
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Jacob JC, Sakakibara K, Mischel RA, Henderson G, Dewey WL, Akbarali HI. Ethanol Reversal of Oxycodone Tolerance in Dorsal Root Ganglia Neurons. Mol Pharmacol 2018; 93:417-426. [PMID: 29467238 DOI: 10.1124/mol.117.110775] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 02/08/2018] [Indexed: 01/23/2023] Open
Abstract
Oxycodone is a semisynthetic opioid compound that is widely prescribed, used, and abused today, and has a well-established role in shaping the current opioid epidemic. Previously, we have shown that tolerance develops to the antinociceptive and respiratory depressive effects of oxycodone in mice, and that a moderate dose of acute ethanol or a protein kinase C (PKC) inhibitor reversed that tolerance. To investigate further if tolerance was occurring through neuronal mechanisms, our aims for this study were to assess the effects of acute and prolonged oxycodone in isolated dorsal root ganglia (DRG) neurons and to determine if this tolerance was reversed by either ethanol or a PKC inhibitor. We found that an acute exposure to 3 μM oxycodone reduced neuronal excitability, as measured by increased threshold potentials and reduced action potential amplitude, without eliciting measurable changes in resting membrane potential. Exposure to 10 μM oxycodone for 18-24 hours prevented oxycodone's effect on neuronal excitability, indicative of tolerance development. The development of opioid tolerance was mitigated in DRG neurons from β-arrestin 2 knockout mice. Oxycodone tolerance was reversed in isolated DRG neurons by the acute application of either ethanol (20 mM) or the PKC inhibitor, bisindolylmaleimide XI hydrochloride (Bis XI), when a challenge of 3 µM oxycodone significantly reduced neuronal excitability following prolonged exposure. Through these studies, we concluded that oxycodone acutely reduced neuronal excitability, tolerance developed to this effect, and reversal of that tolerance occurred at the level of a single neuron, suggesting that reversal of oxycodone tolerance by either ethanol or Bis XI involves cellular mechanisms.
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Affiliation(s)
- Joanna C Jacob
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Kensuke Sakakibara
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Ryan A Mischel
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Graeme Henderson
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia (J.C.J., K.S., R.A.M., W.L.D., H.I.A.); and School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom (G.H.)
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Akbarali HI, Dewey WL. The gut-brain interaction in opioid tolerance. Curr Opin Pharmacol 2017; 37:126-130. [PMID: 29145012 DOI: 10.1016/j.coph.2017.10.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/11/2017] [Accepted: 10/25/2017] [Indexed: 12/11/2022]
Abstract
The prevailing opioid crisis has necessitated the need to understand mechanisms leading to addiction and tolerance, the major contributors to overdose and death and to develop strategies for developing drugs for pain treatment that lack abuse liability and side-effects. Opioids are commonly used for treatment of pain and symptoms of inflammatory bowel disease. The significant effect of opioids in the gut, both acute and chronic, includes persistent constipation and paradoxically may also worsen pain symptoms. Recent work has suggested a significant role of the gastrointestinal microbiome in behavioral responses to opioids, including the development of tolerance to its pain-relieving effects. In this review, we present current concepts of gut-brain interaction in analgesic tolerance to opioids and suggest that peripheral mechanisms emanating from the gut can profoundly affect central control of opioid function.
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Affiliation(s)
- Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 E. Clay St., McGuire Hall 100, Richmond, VA 23298, USA.
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1112 E. Clay St., McGuire Hall 100, Richmond, VA 23298, USA
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Abstract
BACKGROUND Previous evidence suggests that opioid-tolerant patients are less responsive to local anesthetics (LAs) for postoperative pain management. METHODS To determine whether this apparent loss of LA potency is due to an intrinsic change in the peripheral nerve, the effect of systemic morphine was assessed on the potency of lidocaine-induced block of the compound action potential in isolated rat sciatic nerves. Analgesic efficacy was assessed with the heat withdrawal assay. RESULTS While acute administration of 10 mg/kg morphine had no detectable influence on lidocaine potency, seven daily subcutaneous injections of morphine produced a three-fold decrease in potency (EC50 for block A and C waves for naive rats were [mean ± SD] 186 ± 32 μM [n = 6] and 201 ± 31 μM [n = 6], respectively, vs. 608 ± 53 μM [n = 6] and 613 ± 42 μM [n = 6], respectively [P < 0.001], in nerves from rats that had received seven daily injections of morphine [10 mg/kg]). This loss in potency was both dose-dependent and injection number dependent, such that the magnitude of the loss of lidocaine potency was significantly (n = 6; P < 0.01) correlated (r = 0.93) with the development of morphine tolerance. Interestingly, despite the complete recovery of analgesic efficacy within days after cessation of morphine administration, the morphine-induced decrease in lidocaine potency was fully manifest even 35 days after the last morphine injection. Coadministration of naloxone (1 mg/kg, intraperitoneally), but not of naloxone methiodide (1 mg/kg, subcutaneously), with each of seven daily injections of morphine blocked the decrease in lidocaine potency. CONCLUSIONS These preclinical data suggest that the morphine-induced decrease in LA potency is due, at least in part, to the intrinsic changes in the peripheral nerve. Identification of the underlying mechanisms may suggest strategies for more effective postoperative pain management in the growing population of opioid-tolerant patients.
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Fung C, Boesmans W, Cirillo C, Foong JPP, Bornstein JC, Vanden Berghe P. VPAC Receptor Subtypes Tune Purinergic Neuron-to-Glia Communication in the Murine Submucosal Plexus. Front Cell Neurosci 2017; 11:118. [PMID: 28487635 PMCID: PMC5403822 DOI: 10.3389/fncel.2017.00118] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 04/10/2017] [Indexed: 12/20/2022] Open
Abstract
The enteric nervous system (ENS) situated within the gastrointestinal tract comprises an intricate network of neurons and glia which together regulate intestinal function. The exact neuro-glial circuitry and the signaling molecules involved are yet to be fully elucidated. Vasoactive intestinal peptide (VIP) is one of the main neurotransmitters in the gut, and is important for regulating intestinal secretion and motility. However, the role of VIP and its VPAC receptors within the enteric circuitry is not well understood. We investigated this in the submucosal plexus of mouse jejunum using calcium (Ca2+)-imaging. Local VIP application induced Ca2+-transients primarily in neurons and these were inhibited by VPAC1- and VPAC2-antagonists (PG 99-269 and PG 99-465 respectively). These VIP-evoked neural Ca2+-transients were also inhibited by tetrodotoxin (TTX), indicating that they were secondary to action potential generation. Surprisingly, VIP induced Ca2+-transients in glia in the presence of the VPAC2 antagonist. Further, selective VPAC1 receptor activation with the agonist ([K15, R16, L27]VIP(1-7)/GRF(8-27)) predominantly evoked glial responses. However, VPAC1-immunoreactivity did not colocalize with the glial marker glial fibrillary acidic protein (GFAP). Rather, VPAC1 expression was found on cholinergic submucosal neurons and nerve fibers. This suggests that glial responses observed were secondary to neuronal activation. Trains of electrical stimuli were applied to fiber tracts to induce endogenous VIP release. Delayed glial responses were evoked when the VPAC2 antagonist was present. These findings support the presence of an intrinsic VIP/VPAC-initiated neuron-to-glia signaling pathway. VPAC1 agonist-evoked glial responses were inhibited by purinergic antagonists (PPADS and MRS2179), thus demonstrating the involvement of P2Y1 receptors. Collectively, we showed that neurally-released VIP can activate neurons expressing VPAC1 and/or VPAC2 receptors to modulate purine-release onto glia. Selective VPAC1 activation evokes a glial response, whereas VPAC2 receptors may act to inhibit this response. Thus, we identified a component of an enteric neuron-glia circuit that is fine-tuned by endogenous VIP acting through VPAC1- and VPAC2-mediated pathways.
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Affiliation(s)
- Candice Fung
- Department of Physiology, The University of MelbourneParkville, VIC, Australia.,Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU LeuvenLeuven, Belgium
| | - Werend Boesmans
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU LeuvenLeuven, Belgium
| | - Carla Cirillo
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU LeuvenLeuven, Belgium
| | - Jaime P P Foong
- Department of Physiology, The University of MelbourneParkville, VIC, Australia
| | - Joel C Bornstein
- Department of Physiology, The University of MelbourneParkville, VIC, Australia
| | - Pieter Vanden Berghe
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU LeuvenLeuven, Belgium
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The effect of gut microbiome on tolerance to morphine mediated antinociception in mice. Sci Rep 2017; 7:42658. [PMID: 28211545 PMCID: PMC5314392 DOI: 10.1038/srep42658] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 01/12/2017] [Indexed: 02/06/2023] Open
Abstract
There is growing appreciation for the importance of gastrointestinal microbiota in many physiological and pathophysiological processes. While morphine and other narcotics are the most widely prescribed therapy for moderate to severe pain clinically, they have been noted to alter microbial composition and promote bacterial translocation to other tissues. Here we examined the pharmacodynamic properties of chronic morphine in mice following bacterial depletion with oral gavage of an antibiotic cocktail (ABX). ABX significantly reduced gut bacteria and prevented chronic morphine induced increases in gut permeability, colonic mucosal destruction, and colonic IL-1β expression. In addition, ABX prevented the development of antinociceptive tolerance to chronic morphine in both the tail-immersion and acetic acid stretch assays. Morphine tolerance was also reduced by oral vancomycin that has 0% bioavailability. These findings were recapitulated in primary afferent neurons isolated from dorsal root ganglia (DRG) innervating the lower gastrointestinal tract, wherein in-vivo administration of ABX prevented tolerance to morphine-induced hypoexcitability. Finally, though ABX repeatedly demonstrated an ability to prevent tolerance, we show that it did not alter susceptibility to precipitation of withdrawal by naloxone. Collectively, these finding indicate that the gastrointestinal microbiome is an important modulator of physiological responses induced by chronic morphine administration.
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25
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Galligan JJ, Sternini C. Insights into the Role of Opioid Receptors in the GI Tract: Experimental Evidence and Therapeutic Relevance. Handb Exp Pharmacol 2017; 239:363-378. [PMID: 28204957 PMCID: PMC6310692 DOI: 10.1007/164_2016_116] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Opioid drugs are prescribed extensively for pain treatment but when used chronically they induce constipation that can progress to opioid-induced bowel dysfunction. Opioid drugs interact with three classes of opioid receptors: mu opioid receptors (MORs), delta opioid receptors (DOR), and kappa opioid receptors (KORs), but opioid drugs mostly target the MORs. Upon stimulation, opioid receptors couple to inhibitory Gi/Go proteins that activate or inhibit downstream effector proteins. MOR and DOR couple to inhibition of adenylate cyclase and voltage-gated Ca2+ channels and to activation of K+ channels resulting in reduced neuronal activity and neurotransmitter release. KORs couple to inhibition of Ca2+ channels and neurotransmitter release. In the gastrointestinal tract, opioid receptors are localized to enteric neurons, interstitial cells of Cajal, and immune cells. In humans, MOR, DOR, and KOR link to inhibition of acetylcholine release from enteric interneurons and motor neurons and purine/nitric oxide release from inhibitory motor neurons causing inhibition of propulsive motility patterns. MOR and DOR activation also results in inhibition of submucosal secretomotor neurons reducing active Cl- secretion and passive water movement into the colonic lumen. Together, these effects on motility and secretion account for the constipation caused by opioid receptor agonists. Tolerance develops to the analgesic effects of opioid receptor agonists but not to the constipating actions. This may be due to differences in trafficking and downstream signaling in enteric nerves in the colon compared to the small intestine and in neuronal pain pathways. Further studies of differential opioid receptor desensitization and tolerance in subsets of enteric neurons may identify new drug or other treatment strategies of opioid-induced bowel dysfunction.
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Affiliation(s)
- James J Galligan
- Department of Pharmacology and Toxicology and the Neuroscience Program, Michigan State University, 293 Farm Lane, Giltner Hall 108, East Lansing, MI, 48824, USA.
| | - Catia Sternini
- CURE/DDRC, Vatche and Tamar Manoukian Division of Digestive Diseases, Departments of Medicine and Neurobiology, David Geffen School of Medicine, UCLA, Los Angeles, CA, 90095, USA
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26
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Gade AR, Kang M, Khan F, Grider JR, Damaj MI, Dewey WL, Akbarali HI. Enhanced Sensitivity of α3β4 Nicotinic Receptors in Enteric Neurons after Long-Term Morphine: Implication for Opioid-Induced Constipation. J Pharmacol Exp Ther 2016; 357:520-8. [PMID: 27068812 DOI: 10.1124/jpet.116.233304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/08/2016] [Indexed: 11/22/2022] Open
Abstract
Opioid-induced constipation is a major side effect that persists with long-term opioid use. Previous studies demonstrated that nicotine-induced contractions are enhanced after long-term morphine exposure in guinea pig ileum. In the present study, we examined whether the increased sensitivity to nicotine could be observed in single enteric neurons after long-term morphine exposure, determined the subunits in mouse enteric neurons, and examined the effect of nicotine in reversing opioid-induced constipation. Nicotine (0.03-1 mM) dose-dependently induced inward currents from a holding potential of -60 mV in isolated single enteric neurons from the mouse ileum. The amplitude of the currents, but not the potency to nicotine, was significantly increased in neurons receiving long-term (16-24 h) but not short-term (10 min) exposure to morphine. Quantitative mRNA analysis showed that nicotinic acetylcholine receptor (nAChR) subunit expression in the mouse ileum was α3 ≥ β2 > β4 > α5 > α4 > β3 > α6. Nicotine-induced currents were obtained in neurons from α7, β2, α5, and α6 knockout mice. The currents were, however, inhibited by mecamylamine (10 μM) and the α3β4 blocker α-conotoxin AuIB (3 μM), suggesting that nicotine-induced currents were mediated by the α3β4 subtype of nAChRs on enteric neurons. Conversely, NS3861, a partial agonist at α3β4 nAChR, enhanced fecal pellet expulsion in a dose-dependent manner in mice that received long-term, but not short-term, morphine treatment. Overall, our findings suggest that the efficacy of nAChR agonists on enteric neurons is enhanced after long-term morphine exposure, and activation of the α3β4 subtype of nAChR reverses chronic, but not acute, morphine-induced constipation.
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Affiliation(s)
- Aravind R Gade
- Department of Pharmacology and Toxicology (A.R.G., M.K., F.K., M.I.D., W.L.D., H.I.A.), and Department of Physiology and Biophysics (J.R.G.), and VCU Program in Enteric Neuromuscular Sciences (J.R.G., H.I.A.), Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - Minho Kang
- Department of Pharmacology and Toxicology (A.R.G., M.K., F.K., M.I.D., W.L.D., H.I.A.), and Department of Physiology and Biophysics (J.R.G.), and VCU Program in Enteric Neuromuscular Sciences (J.R.G., H.I.A.), Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - Fayez Khan
- Department of Pharmacology and Toxicology (A.R.G., M.K., F.K., M.I.D., W.L.D., H.I.A.), and Department of Physiology and Biophysics (J.R.G.), and VCU Program in Enteric Neuromuscular Sciences (J.R.G., H.I.A.), Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - John R Grider
- Department of Pharmacology and Toxicology (A.R.G., M.K., F.K., M.I.D., W.L.D., H.I.A.), and Department of Physiology and Biophysics (J.R.G.), and VCU Program in Enteric Neuromuscular Sciences (J.R.G., H.I.A.), Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - M Imad Damaj
- Department of Pharmacology and Toxicology (A.R.G., M.K., F.K., M.I.D., W.L.D., H.I.A.), and Department of Physiology and Biophysics (J.R.G.), and VCU Program in Enteric Neuromuscular Sciences (J.R.G., H.I.A.), Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - William L Dewey
- Department of Pharmacology and Toxicology (A.R.G., M.K., F.K., M.I.D., W.L.D., H.I.A.), and Department of Physiology and Biophysics (J.R.G.), and VCU Program in Enteric Neuromuscular Sciences (J.R.G., H.I.A.), Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology (A.R.G., M.K., F.K., M.I.D., W.L.D., H.I.A.), and Department of Physiology and Biophysics (J.R.G.), and VCU Program in Enteric Neuromuscular Sciences (J.R.G., H.I.A.), Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
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Drewes AM, Munkholm P, Simrén M, Breivik H, Kongsgaard UE, Hatlebakk JG, Agreus L, Friedrichsen M, Christrup LL. Definition, diagnosis and treatment strategies for opioid-induced bowel dysfunction–Recommendations of the Nordic Working Group. Scand J Pain 2016; 11:111-122. [DOI: 10.1016/j.sjpain.2015.12.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 12/12/2015] [Indexed: 02/07/2023]
Abstract
Abstract
Background and aims
Opioid-induced bowel dysfunction (OIBD) is an increasing problem due to the common use of opioids for pain worldwide. It manifests with different symptoms, such as dry mouth, gastro-oesophageal reflux, vomiting, bloating, abdominal pain, anorexia, hard stools, constipation and incomplete evacuation. Opioid-induced constipation (OIC) is one of its many symptoms and probably the most prevalent. The current review describes the pathophysiology, clinical implications and treatment of OIBD.
Methods
The Nordic Working Group was formed to provide input for Scandinavian specialists in multiple, relevant areas. Seven main topics with associated statements were defined. The working plan provided a structured format for systematic reviews and included instructions on how to evaluate the level of evidence according to the GRADE guidelines. The quality of evidence supporting the different statements was rated as high, moderate or low. At a second meeting, the group discussed and voted on each section with recommendations (weak and strong) for the statements.
Results
The literature review supported the fact that opioid receptors are expressed throughout the gastrointestinal tract. When blocked by exogenous opioids, there are changes in motility, secretion and absorption of fluids, and sphincter function that are reflected in clinical symptoms. The group supported a recent consensus statement for OIC, which takes into account the change in bowel habits for at least one week rather than focusing on the frequency of bowel movements. Many patients with pain receive opioid therapy and concomitant constipation is associated with increased morbidity and utilization of healthcare resources. Opioid treatment for acute postoperative pain will prolong the postoperative ileus and should also be considered in this context. There are no available tools to assess OIBD, but many rating scales have been developed to assess constipation, and a few specifically address OIC. A clinical treatment strategy for OIBD/OIC was proposed and presented in a flowchart. First-line treatment of OIC is conventional laxatives, lifestyle changes, tapering the opioid dosage and alternative analgesics. Whilst opioid rotation may also improve symptoms, these remain unalleviated in a substantial proportion of patients. Should conventional treatment fail, mechanism-based treatment with opioid antagonists should be considered, and they show advantages over laxatives. It should not be overlooked that many reasons for constipation other than OIBD exist, which should be taken into consideration in the individual patient.
Conclusion and implications
It is the belief of this Nordic Working Group that increased awareness of adverse effects and OIBD, particularly OIC, will lead to better pain treatment in patients on opioid therapy. Subsequently, optimised therapy will improve quality of life and, from a socio-economic perspective, may also reduce costs associated with hospitalisation, sick leave and early retirement in these patients.
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Affiliation(s)
- Asbjørn M. Drewes
- Mech-Sense, Department of Gastroenterology and Hepatology , Aalborg University Hospital , Hobrovej Denmark
| | - Pia Munkholm
- NOH (Nordsjællands Hospital) Gastroenterology , Hillerød Denmark
| | - Magnus Simrén
- Department of Internal Medicine & Clinical Nutrition , Institute of Medicine, Sahlgrenska Academy, University of Gothenburg , Göteborg Sweden
| | - Harald Breivik
- Department of Pain Management and Research , Oslo University Hospital and University of Oslo , Rikshospitalet Norway
| | - Ulf E. Kongsgaard
- Department of Anaesthesiology, Division of Emergencies and Critical Care , Oslo University Hospital, Norway and Medical Faculty, University of Oslo , Rikshospitalet Norway
| | - Jan G. Hatlebakk
- Department of Clinical Medicine , Haukeland University Hospital , Bergen , Norway
| | - Lars Agreus
- Division of Family Medicine , Karolinska Institute , Stockholm , Sweden
| | - Maria Friedrichsen
- Department of Social and Welfare Studies , Faculty of Medicine and Health Sciences , Norrköping , Sweden
| | - Lona L. Christrup
- Department of Drug Design and Pharmacology , Faculty of Health Sciences, University of Copenhagen , københavn Denmark
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Effect of estrogen on morphine- and oxycodone-induced antinociception in a female femur bone cancer pain model. Eur J Pharmacol 2016; 773:1-12. [DOI: 10.1016/j.ejphar.2016.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 12/08/2015] [Accepted: 01/19/2016] [Indexed: 12/24/2022]
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Zamponi GW, Han C, Waxman SG. Voltage-Gated Ion Channels as Molecular Targets for Pain. Transl Neurosci 2016. [DOI: 10.1007/978-1-4899-7654-3_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Fitting S, Ngwainmbi J, Kang M, Khan FA, Stevens DL, Dewey WL, Knapp PE, Hauser KF, Akbarali HI. Sensitization of enteric neurons to morphine by HIV-1 Tat protein. Neurogastroenterol Motil 2015; 27:468-80. [PMID: 25703354 PMCID: PMC4380805 DOI: 10.1111/nmo.12514] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Accepted: 12/31/2014] [Indexed: 12/24/2022]
Abstract
BACKGROUND Gastrointestinal (GI) dysfunction is a major cause of morbidity in acquired immunodeficiency syndrome (AIDS). HIV-1-induced neuropathogenesis is significantly enhanced by opiate abuse, which increases proinflammatory chemokine/cytokine release, the production of reactive species, glial reactivity, and neuronal injury in the central nervous system. Despite marked interactions in the gut, little is known about the effects of HIV-1 in combination with opiate use on the enteric nervous system. METHODS To explore HIV-opiate interactions in myenteric neurons, the effects of Tat ± morphine (0.03, 0.3, and 3 μM) were examined in isolated neurons from doxycycline- (DOX-) inducible HIV-1 Tat(1-86) transgenic mice or following in vitro Tat 100 nM exposure (>6 h). KEY RESULTS Current clamp recordings demonstrated increased neuronal excitability in neurons of inducible Tat(+) mice (Tat+/DOX) compared to control Tat-/DOX mice. In neurons from Tat+/DOX, but not from Tat-/DOX mice, 0.03 μM morphine significantly reduced neuronal excitability, fast transient and late long-lasting sodium currents. There was a significant leftward shift in V(0.5) of inactivation following exposure to 0.03 μM morphine, with a 50% decrease in availability of sodium channels at -100 mV. Similar effects were noted with in vitro Tat exposure in the presence of 0.3 μM morphine. Additionally, GI motility was significantly more sensitive to morphine in Tat(+) mice than Tat(-) mice. CONCLUSIONS & INFERENCES Overall, these data suggest that the sensitivity of enteric neurons to morphine is enhanced in the presence of Tat. Opiates and HIV-1 may uniquely interact to exacerbate the deleterious effects of HIV-1-infection and opiate exposure on GI function.
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Affiliation(s)
- Sylvia Fitting
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298,Corresponding Author: Sylvia Fitting, Ph.D. Dept. Pharmacology and Toxicology Virginia Commonwealth University Richmond, VA 23298 804-628-7579 (phone) 804-827-9974 (FAX)
| | - Joy Ngwainmbi
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298
| | - Minho Kang
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298
| | - Fayez A. Khan
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298
| | - David L. Stevens
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298
| | - William L. Dewey
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298
| | - Pamela E. Knapp
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298,Department of Anatomy & Neurobiology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298
| | - Kurt F. Hauser
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298
| | - Hamid I. Akbarali
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298
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Galligan JJ. HIV, opiates, and enteric neuron dysfunction. Neurogastroenterol Motil 2015; 27:449-54. [PMID: 25817054 PMCID: PMC4380218 DOI: 10.1111/nmo.12539] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 02/09/2015] [Indexed: 12/20/2022]
Abstract
Human immune deficient virus (HIV) is an immunosuppressive virus that targets CD4(+) T-lymphocytes. HIV infections cause increased susceptibility to opportunistic infections and cancer. HIV infection can also alter central nervous system (CNS) function causing cognitive impairment. HIV does not infect neurons but it does infect astrocytes and microglia in the CNS. HIV can also infect enteric glia initiating an intestinal inflammatory response which causes enteric neural injury and gut dysfunction. Part of the inflammatory response is HIV induced production of proteins including, Transactivator of transcription (Tat) which contribute to neuronal injury after release from HIV infected glial cells. A risk factor for HIV infection is intravenous drug use with contaminated needles and chronic opiate use can exacerbate neural injury in the nervous system. While most research focuses on the actions of Tat and other HIV related proteins and opiates on the brain, recent data indicate that Tat can cause intestinal inflammation and disruption of enteric neuron function, including alteration of Na(+) channel activity and action potential generation. A paper published in this issue of Neurogastroenterology and Motility extends these findings by identifying an interaction between Tat and morphine on enteric neuron Na(+) channels and on intestinal motility in vivo using a Tat expressing transgenic mouse model. These new data show that Tat protein can enhance the inhibitory actions of morphine on action potential generation and propulsive motility. These findings are important to our understanding of how HIV causes diarrhea in infected patients and for the use of opioid drugs to treat HIV-induced diarrhea.
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Affiliation(s)
- James J. Galligan
- Neuroscience Program and the Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824
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Wu J, Liu B, Tong W, Zhang A, Li F, Lin J, Wang LI. Opioid receptors and associated regulator of G protein signaling are involved in the cathartic colon of rats. Exp Ther Med 2015; 9:1229-1234. [PMID: 25780414 PMCID: PMC4353748 DOI: 10.3892/etm.2015.2233] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 12/12/2014] [Indexed: 02/06/2023] Open
Abstract
A cathartic colon is characteristic of slow transit constipation (STC), which can result following the long-term use of irritant laxatives. In the present study, the involvement of three opioid receptor subtypes (μ, MOR; δ, DOR; and κ, KOR), regulator of G protein signaling 4 (RGS-4) and β-arrestin-2 were investigated in the cathartic colon of rats. A rat model of a cathartic colon was established by feeding the animals with phenolphthalein, while normal rats were used as a control. The mRNA and protein expression levels of the opioid receptors, RGS-4 and β-arrestin-2 were detected in the rat colon using semi-quantitative reverse transcription polymerase chain reaction and western blot analysis, respectively. The rat model of a cathartic colon was successfully established using the phenolphthalein stimulus, and was shown to result in shrunken myenteric neurons and loose muscle fibers in the intestinal wall. The mRNA and protein expression levels of the three opioid receptor subtypes, RGS-4 and β-arrestin-2 were significantly higher in the cathartic colon group when compared with the levels in the normal control group (all P<0.01). With regard to the protein expression levels, MOR protein increased 2.4 fold, DOR expression increased 1.5 fold, KOR levels increased 1.5 fold, RGS-4 protein increased 3.5 fold and β-arrestin-2 expression increased 2.0 fold. Therefore, the expression levels of opioid receptors were found to increase in the cathartic colons of the rats, indicating that opioid receptors and downstream RGS-4 and β-arrestin-2 signaling may play an important role in the pathogenesis of STC.
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Affiliation(s)
- Jinsong Wu
- Department of General Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China ; Second Department of General Surgery, Bethune International Peace Hospital of People's Liberty Army, Shijiazhuang, Hebei 050082, P.R. China
| | - Baohua Liu
- Department of General Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
| | - Weidong Tong
- Department of General Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
| | - Anping Zhang
- Department of General Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
| | - Fan Li
- Department of General Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
| | - Jing Lin
- Department of Nephrology, Bethune International Peace Hospital of People's Liberty Army, Shijiazhuang, Hebei 050082, P.R. China
| | - L I Wang
- Department of General Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
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Abstract
The gastrointestinal (GI) tract presents a major site of immune modulation by HIV, resulting in significant morbidity. Most GI processes affected during HIV infection are regulated by the enteric nervous system. HIV has been identified in GI histologic specimens in up to 40% of patients, and the presence of viral proteins, including the trans-activator of transcription (Tat), has been reported in the gut indicating that HIV itself may be an indirect gut pathogen. Little is known of how Tat affects the enteric nervous system. Here we investigated the effects of the Tat protein on enteric neuronal excitability, proinflammatory cytokine release, and its overall effect on GI motility. Direct application of Tat (100 nm) increased the number of action potentials and reduced the threshold for action potential initiation in isolated myenteric neurons. This effect persisted in neurons pretreated with Tat for 3 d (19 of 20) and in neurons isolated from Tat(+) (Tat-expressing) transgenic mice. Tat increased sodium channel isoforms Nav1.7 and Nav1.8 levels. This increase was accompanied by an increase in sodium current density and a leftward shift in the sodium channel activation voltage. RANTES, IL-6, and IL-1β, but not TNF-α, were enhanced by Tat. Intestinal transit and cecal water content were also significantly higher in Tat(+) transgenic mice than Tat(-) littermates (controls). Together, these findings show that Tat has a direct and persistent effect on enteric neuronal excitability, and together with its effect on proinflammatory cytokines, regulates gut motility, thereby contributing to GI dysmotilities reported in HIV patients.
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Abstract
This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 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, Flushing, NY 11367, United States.
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Akbarali HI, Inkisar A, Dewey WL. Site and mechanism of morphine tolerance in the gastrointestinal tract. Neurogastroenterol Motil 2014; 26:1361-7. [PMID: 25257923 PMCID: PMC4423201 DOI: 10.1111/nmo.12443] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 08/24/2014] [Indexed: 12/23/2022]
Abstract
Opioid-induced constipation is a major clinical problem. The effects of morphine, and other narcotics, on the gastrointestinal tract persist over long-term use thus limiting the clinical benefit of these excellent pain relievers. The effects of opioids in the gut, including morphine, are largely mediated by the μ-opioid receptors at the soma and nerve terminals of enteric neurons. Recent studies demonstrate that regional differences exist in both acute and chronic morphine along the gastrointestinal tract. While tolerance develops to the analgesic effects and upper gastrointestinal motility upon repeated morphine administration, tolerance does not develop in the colon with chronic opioids resulting in persistent constipation. Here, we review the mechanisms by which tolerance develops in the small but not the large intestine. The regional differences lie in the signaling and regulation of the μ-opioid receptor in the various segments of the gastrointestinal tract. The differential role of β-arrestin2 in tolerance development between central and enteric neurons defines the potential for therapeutic approaches in developing ligands with analgesic properties and minimal constipating effects.
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Affiliation(s)
- H. I. Akbarali
- Department of Pharmacology and Toxicology; Virginia Commonwealth University; Richmond VA USA
| | - A. Inkisar
- Department of Pharmacology and Toxicology; Virginia Commonwealth University; Richmond VA USA
| | - W. L. Dewey
- Department of Pharmacology and Toxicology; Virginia Commonwealth University; Richmond VA USA
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Ono H, Nakamura A, Matsumoto K, Horie S, Sakaguchi G, Kanemasa T. Circular muscle contraction in the mice rectum plays a key role in morphine-induced constipation. Neurogastroenterol Motil 2014; 26:1396-407. [PMID: 25041353 DOI: 10.1111/nmo.12387] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 06/06/2014] [Indexed: 12/19/2022]
Abstract
BACKGROUND Although opioids induce intestinal muscle contraction and provoke constipation, the intestinal region(s) that contribute to the constipation have remained unclear. We report here a region-specific response of intestinal muscle contraction to morphine and its correlation with in vivo constipation. METHODS Regions of mice small and large intestines were dissected histologically and circular muscle contractile responses were measured using isometric transducers. Bead expulsion assays were performed to assess in vivo constipation. KEY RESULTS The strongest contraction in response to morphine was detected in the rectum. The distal and transverse colon also showed strong contractions, whereas weak responses were detected in the proximal colon, jejunum, and ileum. Regarding the sustainability of muscle contractions during morphine exposure, prolonged waves were detected only in the rectum, while the waves diminished gradually in other regions. To identify the mechanism(s) underlying this difference, we focused on nitric oxide synthase (NOS). In the distal colon, decreased contraction during morphine exposure was recovered by application of a NOS inhibitor (L-NAME), while a NOS substrate (L-arginine) enhanced contractile degradation. In contrast L-NAME and L-arginine modestly affected the sustained contraction in the rectum. To confirm the correlation with constipation, beads were inserted into the transverse colon, distal colon, or rectum after morphine administration and expulsion times were examined. Beads tended to stop at the rectum even when inserted in the deeper colonic regions. CONCLUSIONS & INFERENCES The rectum showed the greatest response to morphine in both in vitro and in vivo analyses, therefore it may play a key role for opioid-induced constipation.
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Affiliation(s)
- H Ono
- Pain & Neurology, Medicinal Research Laboratories, Shionogi and Co., Ltd., Toyonaka, Osaka, Japan
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37
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Galligan JJ, Akbarali HI. Molecular physiology of enteric opioid receptors. AMERICAN JOURNAL OF GASTROENTEROLOGY SUPPLEMENTS (PRINT) 2014; 2:17-21. [PMID: 25207608 PMCID: PMC4426191 DOI: 10.1038/ajgsup.2014.5] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Opioid drugs have powerful antidiarrheal effects and many patients taking these drugs for chronic pain relief experience chronic constipation that can progress to opioid-induced bowel dysfunction. Three classes of opioid receptors are expressed by enteric neurons: μ-, δ-, and κ-opioid receptors (MOR, DOR, and KOR). MOR and DOR couple to inhibition of adenylate cylase and nerve terminal Ca(2+) channels and activation of K(+) channels. These effects reduce neuronal activity and neurotransmitter release. KOR couples to inhibition of Ca(2+) channels and inhibition of neurotransmitter release. In the human gastrointestinal tract, MOR, DOR, and KOR link to inhibition of acetylcholine release from enteric interneurons and purine/nitric oxide release from inhibitory motorneurons. These actions inhibit propulsive motility. MOR and DOR also link to inhibition of submucosal secretomotor neurons, reducing active Cl(-) secretion and passive water movement into the colonic lumen. These effects account for the constipation caused by opioid receptor agonists. Tolerance develops to the analgesic effects of opioid receptor agonists but not to the constipating actions. This may be due to differential β-arrestin-2-dependent opioid receptor desensitization and internalization in enteric nerves in the colon compared with the small intestine and in neuronal pain pathways. Further studies of differential opioid receptor desensitization and tolerance in subsets of enteric neurons may identify new drugs or other treatment strategies of opioid-induced bowel dysfunction.
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Affiliation(s)
- James J. Galligan
- Department of Pharmacology and Toxicology and the Neuroscience Program, Michigan State University, E. Lansing, Michigan, USA
| | - Hamid I. Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
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Smith TH, Ngwainmbi J, Hashimoto A, Dewey WL, Akbarali HI. Morphine dependence in single enteric neurons from the mouse colon requires deletion of β-arrestin2. Physiol Rep 2014; 2:2/9/e12140. [PMID: 25194025 PMCID: PMC4270231 DOI: 10.14814/phy2.12140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Chronic administration of morphine results in the development of tolerance to the analgesic effects and to inhibition of upper gastrointestinal motility but not to colonic motility, resulting in persistent constipation. In this study we examined the effect of chronic morphine in myenteric neurons from the adult mouse colon. Similar to the ileum, distinct neuronal populations exhibiting afterhyperpolarization (AHP)-positive and AHP-negative neurons were identified in the colon. Acute morphine (3 μM) decreased the number of action potentials, and increased the threshold for action potential generation indicative of reduced excitability in AHP-positive neurons. In neurons from the ileum of mice that were rendered antinociceptive tolerant by morphine-pellet implantation for 5 days, the opioid antagonist naloxone precipitated withdrawal as evidenced by increased neuronal excitability. Overnight incubation of ileum neurons with morphine also resulted in enhanced excitability to naloxone. Colonic neurons exposed to long-term morphine, remained unresponsive to naloxone suggesting that precipitated withdrawal does not occur in colonic neurons. However, morphine-treated colonic neurons from β-arrestin2 knockout mice demonstrated increased excitability upon treatment with naloxone as assessed by change in rheobase, number of action potentials and input resistance. These data suggest that similar to the ileum, acute exposure to morphine in colonic neurons results in reduced excitability due to inhibition of sodium currents. However, unlike the ileum, dependence to chronic exposure of morphine develops in colonic neurons from the β-arrestin2 knockout mice. These studies corroborate the in-vivo findings of the differential role of neuronal β-arrestin2 in the development of morphine tolerance/dependence in the ileum and colon.
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Affiliation(s)
- Tricia H Smith
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Joy Ngwainmbi
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Atsushi Hashimoto
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
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Specific localization of β-Arrestin2 in myenteric plexus of mouse gastrointestinal tract. PLoS One 2014; 9:e103894. [PMID: 25083714 PMCID: PMC4119012 DOI: 10.1371/journal.pone.0103894] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 07/08/2014] [Indexed: 12/31/2022] Open
Abstract
β-arrestin2 is a key molecule involved in signaling and internalization of activated G protein-coupled receptors including µ-opioid receptors (MOR). Previously we have shown that decreased expression of β-arrestin2 upon chronic morphine is associated with the development of opioid tolerance in the gastrointestinal tract. However, the localization of β-arrestin2 within the gastrointestinal wall is not known. In this study we found that β-arrestin2 is localized in the soma of a select group of neurons in the myenteric ganglia but not in smooth muscle. The density of β-arestin2 was significantly higher in the ileum than the colon. We identified four variants of β-arrestin2 in the ileum, with ARRB-005 and ARRB-013 being the most abundant. Further, the current study utilized multiple-labeling immunofluorescence to characterize the chemical coding of neurons expressing β-arrestin2 in the murine myenteric plexus and the co-localization of MOR1 and β-arrestin2. β-arrestin2 co-localized with choline acetyltransferase and calretinin. In contrast, β-arrestin2 neither co-localized with substance P, nitric oxide synthase nor calbindin. Genetic deletion of β-arrestin2 did not affect cholinergic neuron activation by nicotine in the isolated ileum (-log M EC50: wild type = 5.8 vs. β-arrestin2 knockout = 5.9). Our findings suggest specificity in the localization of β-arrestin2 in the myenteric plexus within MOR1-expressing neurons and provide a relation for direct intracellular crosstalk between MOR1 receptor activation and β-arrestin2 signaling in the myenteric neurons. β-arrestin2 deletion does not directly alter basal enteric cholinergic neuronal function.
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40
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Bourinet E, Altier C, Hildebrand ME, Trang T, Salter MW, Zamponi GW. Calcium-permeable ion channels in pain signaling. Physiol Rev 2014; 94:81-140. [PMID: 24382884 DOI: 10.1152/physrev.00023.2013] [Citation(s) in RCA: 208] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The detection and processing of painful stimuli in afferent sensory neurons is critically dependent on a wide range of different types of voltage- and ligand-gated ion channels, including sodium, calcium, and TRP channels, to name a few. The functions of these channels include the detection of mechanical and chemical insults, the generation of action potentials and regulation of neuronal firing patterns, the initiation of neurotransmitter release at dorsal horn synapses, and the ensuing activation of spinal cord neurons that project to pain centers in the brain. Long-term changes in ion channel expression and function are thought to contribute to chronic pain states. Many of the channels involved in the afferent pain pathway are permeable to calcium ions, suggesting a role in cell signaling beyond the mere generation of electrical activity. In this article, we provide a broad overview of different calcium-permeable ion channels in the afferent pain pathway and their role in pain pathophysiology.
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Smith TH, Ngwainmbi J, Grider JR, Dewey WL, Akbarali HI. An in-vitro preparation of isolated enteric neurons and glia from the myenteric plexus of the adult mouse. J Vis Exp 2013:50688. [PMID: 23962959 PMCID: PMC3846983 DOI: 10.3791/50688] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The enteric nervous system is a vast network of neurons and glia running the length of the gastrointestinal tract that functionally controls gastrointestinal motility. A procedure for the isolation and culture of a mixed population of neurons and glia from the myenteric plexus is described. The primary cultures can be maintained for over 7 days, with connections developing among the neurons and glia. The longitudinal muscle strip with the attached myenteric plexus is stripped from the underlying circular muscle of the mouse ileum or colon and subjected to enzymatic digestion. In sterile conditions, the isolated neuronal and glia population are preserved within the pellet following centrifugation and plated on coverslips. Within 24-48 hr, neurite outgrowth occurs and neurons can be identified by pan-neuronal markers. After two days in culture, isolated neurons fire action potentials as observed by patch clamp studies. Furthermore, enteric glia can also be identified by GFAP staining. A network of neurons and glia in close apposition forms within 5-7 days. Enteric neurons can be individually and directly studied using methods such as immunohistochemistry, electrophysiology, calcium imaging, and single-cell PCR. Furthermore, this procedure can be performed in genetically modified animals. This methodology is simple to perform and inexpensive. Overall, this protocol exposes the components of the enteric nervous system in an easily manipulated manner so that we may better discover the functionality of the ENS in normal and disease states.
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Affiliation(s)
- Tricia H Smith
- Pharmacology and Toxicology, Virginia Commonwealth University, USA
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