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Köhne S, Hillemacher T, Glahn A, Bach P. Emerging drugs in phase II and III clinical development for the treatment of alcohol use disorder. Expert Opin Emerg Drugs 2024:1-14. [PMID: 38606899 DOI: 10.1080/14728214.2024.2342951] [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: 12/15/2023] [Accepted: 04/10/2024] [Indexed: 04/13/2024]
Abstract
INTRODUCTION Alcohol Use Disorder (AUD) poses an ongoing significant global health burden. AUD is highly prevalent and affects not only the individuals with AUD, but also their communities and society at large. Even though pharmacotherapy is an integral part of AUD treatment, the few available substances show limited efficacy and limited clinical impact. Thus, there is a need for new innovative pharmacotherapeutic approaches. AREAS COVERED This paper provides a comprehensive review of drugs approved for the treatment of AUD as well as those currently in phase II and III development. Data from recent clinical trials has been reviewed and supplemented by additional literature based on a systematic search of the PubMed database and clinical trials registries. Compounds discussed include disulfiram, naltrexone, nalmefene, acamprosat, baclofen, sodium oxybate, doxazosin, varenicline, zonisamide, gabapentin, apremilast, ibudilast, ivermectin, tolcapone, mifepristone, suvorexant, ketamine, psilocybin, semaglutide, oxytocin and cannabidiol. EXPERT OPINION Even though the majority of the discussed compounds lack sufficient evidence to support their efficacy, multiple promising new treatment options are currently under investigation. Future research has to consider specific phenotypes and subgroups of AUD as well as a possible enhancement of the effects of psychotherapy through combination with pharmacotherapy. Practitioners should be encouraged to use available compounds to support existing therapeutic regimens.
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Affiliation(s)
- Sophie Köhne
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Medical School Hannover, Hannover, Germany
| | - Thomas Hillemacher
- Department of Psychiatry and Psychotherapy, Paracelsus Medical University Nuremberg, Nürnberg, Germany
| | - Alexander Glahn
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Medical School Hannover, Hannover, Germany
| | - Patrick Bach
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim. Heidelberg University, Heidelberg, Germany
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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2
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Wadsworth HA, Warnecke AMP, Barlow JC, Robinson JK, Steimle E, Ronström JW, Williams PE, Galbraith CJ, Baldridge J, Jakowec MW, Davies DL, Yorgason JT. Ivermectin increases striatal cholinergic activity to facilitate dopamine terminal function. Cell Biosci 2024; 14:50. [PMID: 38632622 PMCID: PMC11025261 DOI: 10.1186/s13578-024-01228-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 04/01/2024] [Indexed: 04/19/2024] Open
Abstract
Ivermectin (IVM) is a commonly prescribed antiparasitic treatment with pharmacological effects on invertebrate glutamate ion channels resulting in paralysis and death of invertebrates. However, it can also act as a modulator of some vertebrate ion channels and has shown promise in facilitating L-DOPA treatment in preclinical models of Parkinson's disease. The pharmacological effects of IVM on dopamine terminal function were tested, focusing on the role of two of IVM's potential targets: purinergic P2X4 and nicotinic acetylcholine receptors. Ivermectin enhanced electrochemical detection of dorsal striatum dopamine release. Although striatal P2X4 receptors were observed, IVM effects on dopamine release were not blocked by P2X4 receptor inactivation. In contrast, IVM attenuated nicotine effects on dopamine release, and antagonizing nicotinic receptors prevented IVM effects on dopamine release. IVM also enhanced striatal cholinergic interneuron firing. L-DOPA enhances dopamine release by increasing vesicular content. L-DOPA and IVM co-application further enhanced release but resulted in a reduction in the ratio between high and low frequency stimulations, suggesting that IVM is enhancing release largely through changes in terminal excitability and not vesicular content. Thus, IVM is increasing striatal dopamine release through enhanced cholinergic activity on dopamine terminals.
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Affiliation(s)
- Hillary A Wadsworth
- Department of Cellular Biology and Physiology, and Neuroscience Program, Brigham Young University, 4005 LSB, Provo, UT, 84602, USA
| | - Alicia M P Warnecke
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90089, USA
| | - Joshua C Barlow
- Department of Cellular Biology and Physiology, and Neuroscience Program, Brigham Young University, 4005 LSB, Provo, UT, 84602, USA
| | - J Kayden Robinson
- Department of Cellular Biology and Physiology, and Neuroscience Program, Brigham Young University, 4005 LSB, Provo, UT, 84602, USA
| | - Emma Steimle
- Department of Cellular Biology and Physiology, and Neuroscience Program, Brigham Young University, 4005 LSB, Provo, UT, 84602, USA
| | - Joakim W Ronström
- Department of Cellular Biology and Physiology, and Neuroscience Program, Brigham Young University, 4005 LSB, Provo, UT, 84602, USA
| | - Pacen E Williams
- Department of Cellular Biology and Physiology, and Neuroscience Program, Brigham Young University, 4005 LSB, Provo, UT, 84602, USA
| | - Christopher J Galbraith
- Department of Cellular Biology and Physiology, and Neuroscience Program, Brigham Young University, 4005 LSB, Provo, UT, 84602, USA
| | - Jared Baldridge
- Department of Cellular Biology and Physiology, and Neuroscience Program, Brigham Young University, 4005 LSB, Provo, UT, 84602, USA
| | - Michael W Jakowec
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90089, USA
| | - Daryl L Davies
- Department of Neurology, Keck School of Medicine, University of Southern California, 1333 San Pablo Street, Los Angeles, CA, 90033, USA
| | - Jordan T Yorgason
- Department of Cellular Biology and Physiology, and Neuroscience Program, Brigham Young University, 4005 LSB, Provo, UT, 84602, USA.
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3
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Velho MC, Fontana de Andrade D, Beck RCR. Ivermectin: recent approaches in the design of novel veterinary and human medicines. Pharm Dev Technol 2022; 27:865-880. [PMID: 36062978 DOI: 10.1080/10837450.2022.2121840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Ivermectin (IVM) is a drug widely used in veterinary and human medicine for the management of parasitic diseases. Its repositioning potential has been recently considered for the treatment of different diseases, such as cancer and viral infections. However, IVM faces some limitations to its formulations due to its low water solubility and bioavailability, along with reports of drug resistance. In this sense, novel technological approaches have been explored to optimize its formulations and/or to develop innovative medicines. Therefore, this review discusses the strategies proposed in the last decade to improve the safety and efficacy of IVM and to explore its novel therapeutic applications. Among these technologies, the use of micro/nano-drug delivery systems is the most used approach, followed by long-acting formulations. In general, the development of these novel formulations seems to run side by side in veterinary and human health, showing a shared interface between the two areas. Although the technologies proposed indicate a promising future in the development of innovative dosage forms containing IVM, its safety and therapeutic targets must be further evaluated. Overall, these approaches comprise tailoring drug delivery profiles, decreasing the risks of developing drug resistance, and supporting the application of IVM for reaching different therapeutic targets.
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Affiliation(s)
- Maiara Callegaro Velho
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil.,Laboratório de Nanocarreadores e Impressão 3D em Tecnologia Farmacêutica (Nano3D), Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre
| | - Diego Fontana de Andrade
- Departamento de Produção e Controle de Matéria-Prima, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil.,Laboratório de Nanocarreadores e Impressão 3D em Tecnologia Farmacêutica (Nano3D), Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre
| | - Ruy Carlos Ruver Beck
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil.,Departamento de Produção e Controle de Medicamentos, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil.,Laboratório de Nanocarreadores e Impressão 3D em Tecnologia Farmacêutica (Nano3D), Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre
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Sophocleous RA, Ooi L, Sluyter R. The P2X4 Receptor: Cellular and Molecular Characteristics of a Promising Neuroinflammatory Target. Int J Mol Sci 2022; 23:ijms23105739. [PMID: 35628550 PMCID: PMC9147237 DOI: 10.3390/ijms23105739] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 02/07/2023] Open
Abstract
The adenosine 5′-triphosphate-gated P2X4 receptor channel is a promising target in neuroinflammatory disorders, but the ability to effectively target these receptors in models of neuroinflammation has presented a constant challenge. As such, the exact role of P2X4 receptors and their cell signalling mechanisms in human physiology and pathophysiology still requires further elucidation. To this end, research into the molecular mechanisms of P2X4 receptor activation, modulation, and inhibition has continued to gain momentum in an attempt to further describe the role of P2X4 receptors in neuroinflammation and other disease settings. Here we provide an overview of the current understanding of the P2X4 receptor, including its expression and function in cells involved in neuroinflammatory signalling. We discuss the pharmacology of P2X4 receptors and provide an overview of P2X4-targeting molecules, including agonists, positive allosteric modulators, and antagonists. Finally, we discuss the use of P2X4 receptor modulators and antagonists in models of neuroinflammatory cell signalling and disease.
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Affiliation(s)
- Reece Andrew Sophocleous
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; (R.A.S.); (L.O.)
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; (R.A.S.); (L.O.)
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Ronald Sluyter
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; (R.A.S.); (L.O.)
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Correspondence: ; Tel.: +612-4221-5508
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5
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Abstract
P2X4 receptors are found throughout the central nervous system, and studies have shown that these purinergic receptors are important regulators of alcohol intake. The ventral tegmental area (VTA) is an important region for the rewarding and reinforcing properties of alcohol, but the role of P2X4 receptors in this region is unknown. Using both immunohistochemical and electrophysiological methods, we examined the interaction between P2X4 receptors and alcohol on VTA neurons. Incubation of brain slices containing the VTA for 2 h with siRNA targeting P2X4 receptors resulted in about a 25% reduction in P2X4 immunoreactivity in tyrosine hydroxylase positive VTA neurons. In electrophysiological experiments, ATP (0.5-3 mM) produced a reduction in the spontaneous firing rate, and ethanol significantly reduced this inhibition. Exposure to siP2X4 for 2 h via the recording micropipette resulted in a suppression of the response of VTA neurons to ATP, but no significant reduction in the ethanol inhibition of the ATP response was observed after this P2X4 downregulation. These results support the idea that VTA neurons are inhibited by ATP, ethanol antagonizes this inhibition, and the ethanol-sensitive component of ATP inhibition is mediated by P2X4 receptors. This interaction of ethanol with P2X4 receptors may be an important regulator of the rewarding effects of ethanol, making P2X4 receptors an intriguing target for the development of agents to treat alcohol use disorders.
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Silva J, Carry E, Xue C, Zhang J, Liang J, Roberge JY, Davies DL. A Novel Dual Drug Approach That Combines Ivermectin and Dihydromyricetin (DHM) to Reduce Alcohol Drinking and Preference in Mice. Molecules 2021; 26:molecules26061791. [PMID: 33810134 PMCID: PMC8004700 DOI: 10.3390/molecules26061791] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 12/12/2022] Open
Abstract
Alcohol use disorder (AUD) affects over 18 million people in the US. Unfortunately, pharmacotherapies available for AUD have limited clinical success and are under prescribed. Previously, we established that avermectin compounds (ivermectin [IVM] and moxidectin) reduce alcohol (ethanol/EtOH) consumption in mice, but these effects are limited by P-glycoprotein (Pgp/ABCB1) efflux. The current study tested the hypothesis that dihydromyricetin (DHM), a natural product suggested to inhibit Pgp, will enhance IVM potency as measured by changes in EtOH consumption. Using a within-subjects study design and two-bottle choice study, we tested the combination of DHM (10 mg/kg; i.p.) and IVM (0.5–2.5 mg/kg; i.p.) on EtOH intake and preference in male and female C57BL/6J mice. We also conducted molecular modeling studies of DHM with the nucleotide-binding domain of human Pgp that identified key binding residues associated with Pgp inhibition. We found that DHM increased the potency of IVM in reducing EtOH consumption, resulting in significant effects at the 1.0 mg/kg dose. This combination supports our hypothesis that inhibiting Pgp improves the potency of IVM in reducing EtOH consumption. Collectively, we demonstrate the feasibility of this novel combinatorial approach in reducing EtOH consumption and illustrate the utility of DHM in a novel combinatorial approach.
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Affiliation(s)
- Joshua Silva
- Titus Family Department of Clinical Pharmacy, University of Southern California School of Pharmacy, Los Angeles, CA 90089, USA; (J.S.); (C.X.); (J.Z.); (J.L.)
| | - Eileen Carry
- Molecular Design and Synthesis Group, Rutgers University Biomedical Research Innovation Core, Piscataway, NJ 08854, USA; (E.C.); (J.Y.R.)
| | - Chen Xue
- Titus Family Department of Clinical Pharmacy, University of Southern California School of Pharmacy, Los Angeles, CA 90089, USA; (J.S.); (C.X.); (J.Z.); (J.L.)
| | - Jifeng Zhang
- Titus Family Department of Clinical Pharmacy, University of Southern California School of Pharmacy, Los Angeles, CA 90089, USA; (J.S.); (C.X.); (J.Z.); (J.L.)
| | - Jing Liang
- Titus Family Department of Clinical Pharmacy, University of Southern California School of Pharmacy, Los Angeles, CA 90089, USA; (J.S.); (C.X.); (J.Z.); (J.L.)
| | - Jacques Y. Roberge
- Molecular Design and Synthesis Group, Rutgers University Biomedical Research Innovation Core, Piscataway, NJ 08854, USA; (E.C.); (J.Y.R.)
| | - Daryl L. Davies
- Titus Family Department of Clinical Pharmacy, University of Southern California School of Pharmacy, Los Angeles, CA 90089, USA; (J.S.); (C.X.); (J.Z.); (J.L.)
- Correspondence: ; Tel.: +13-23-442-1427
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7
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Szopa A, Socała K, Serefko A, Doboszewska U, Wróbel A, Poleszak E, Wlaź P. Purinergic transmission in depressive disorders. Pharmacol Ther 2021; 224:107821. [PMID: 33607148 DOI: 10.1016/j.pharmthera.2021.107821] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022]
Abstract
Purinergic signaling involves the actions of purine nucleotides and nucleosides (such as adenosine) at P1 (adenosine), P2X, and P2Y receptors. Here, we present recent data contributing to a comprehensive overview of the association between purinergic signaling and depression. We start with background information on adenosine production and metabolism, followed by a detailed characterization of P1 and P2 receptors, with an emphasis on their expression and function in the brain as well as on their ligands. We provide data suggestive of altered metabolism of adenosine in depressed patients, which might be regarded as a disease biomarker. We then turn to considerable amount of preclinical/behavioral data obtained with the aid of the forced swim test, tail suspension test, learned helplessness model, or unpredictable chronic mild stress model and genetic activation/inactivation of P1 or P2 receptors as well as nonselective or selective ligands of P1 or P2 receptors. We also aimed to discuss the reason underlying discrepancies observed in such studies.
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Affiliation(s)
- Aleksandra Szopa
- Department of Applied and Social Pharmacy, Laboratory of Preclinical Testing, Medical University of Lublin, Chodźki 1, PL 20-093 Lublin, Poland.
| | - Katarzyna Socała
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033 Lublin, Poland
| | - Anna Serefko
- Department of Applied and Social Pharmacy, Laboratory of Preclinical Testing, Medical University of Lublin, Chodźki 1, PL 20-093 Lublin, Poland
| | - Urszula Doboszewska
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033 Lublin, Poland
| | - Andrzej Wróbel
- Second Department of Gynecology, Medical University of Lublin, Jaczewskiego 8, PL 20-090 Lublin, Poland
| | - Ewa Poleszak
- Department of Applied and Social Pharmacy, Laboratory of Preclinical Testing, Medical University of Lublin, Chodźki 1, PL 20-093 Lublin, Poland.
| | - Piotr Wlaź
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033 Lublin, Poland.
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Cross-Talk between P2X and NMDA Receptors. Int J Mol Sci 2020; 21:ijms21197187. [PMID: 33003406 PMCID: PMC7582700 DOI: 10.3390/ijms21197187] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/18/2020] [Accepted: 09/25/2020] [Indexed: 02/01/2023] Open
Abstract
Purinergic P2X receptors (P2X) are ATP-gated ion channels widely expressed in the CNS. While the direct contribution of P2X to synaptic transmission is uncertain, P2X reportedly affect N-methyl-D-aspartate receptor (NMDAR) activity, which has given rise to competing theories on the role of P2X in the modulation of synapses. However, P2X have also been shown to participate in receptor cross-talk: an interaction where one receptor (e.g., P2X2) directly influences the activity of another (e.g., nicotinic, 5-HT3 or GABA receptors). In this study, we tested for interactions between P2X2 or P2X4 and NMDARs. Using two-electrode voltage-clamp electrophysiology experiments in Xenopus laevis oocytes, we demonstrate that both P2X2 and P2X4 interact with NMDARs in an inhibited manner. When investigating the molecular domains responsible for this phenomenon, we found that the P2X2 c-terminus (CT) could interfere with both P2X2 and P2X4 interactions with NMDARs. We also report that 11 distal CT residues on the P2X4 facilitate the P2X4–NMDAR interaction, and that a peptide consisting of these P2X4 CT residues (11C) can disrupt the interaction between NMDARs and P2X2 or P2X4. Collectively, these results provide new evidence for the modulatory nature of P2X2 and P2X4, suggesting they might play a more nuanced role in the CNS.
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Implication of Neuronal Versus Microglial P2X4 Receptors in Central Nervous System Disorders. Neurosci Bull 2020; 36:1327-1343. [PMID: 32889635 DOI: 10.1007/s12264-020-00570-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 05/06/2020] [Indexed: 02/08/2023] Open
Abstract
The P2X4 receptor (P2X4) is an ATP-gated cation channel that is highly permeable to Ca2+ and widely expressed in neuronal and glial cell types throughout the central nervous system (CNS). A growing body of evidence indicates that P2X4 plays key roles in numerous central disorders. P2X4 trafficking is highly regulated and consequently in normal situations, P2X4 is present on the plasma membrane at low density and found mostly within intracellular endosomal/lysosomal compartments. An increase in the de novo expression and/or surface density of P2X4 has been observed in microglia and/or neurons during pathological states. This review aims to summarize knowledge on P2X4 functions in CNS disorders and provide some insights into the relative contributions of neuronal and glial P2X4 in pathological contexts. However, determination of the cell-specific functions of P2X4 along with its intracellular and cell surface roles remain to be elucidated before its potential as a therapeutic target in multiple disorders can be defined.
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Warnecke AMP, Kang MS, Jakowec MW, Davies DL. The macrocyclic lactones ivermectin and moxidectin show differential effects on rotational behavior in the 6-hydroxydopamine mouse model of Parkinson's disease. Behav Brain Res 2020; 393:112804. [PMID: 32668263 DOI: 10.1016/j.bbr.2020.112804] [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: 03/04/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 11/27/2022]
Abstract
Parkinson's disease (PD) is a common neurodegenerative disease characterized by motor and cognitive deficits, the result of dopamine (DA)-depletion within the basal ganglia. Currently, DA replacement therapy in the form of Sinemet (L-DOPA plus Carbidopa) provides symptomatic motor benefits and remains the "gold standard" for treatment. Several pharmacological approaches can enhance DA neurotransmission including the administration of DA receptor agonists, the inhibition of DA metabolism, and enhancing pre-synaptic DA release. DA neurotransmission is regulated by several receptor subtypes including signaling through the purinergic system. P2 × 4 receptors (P2 × 4Rs) are a class of cation-permeable ligand-gated ion channels activated by the synaptic release of extracellular adenosine 5'-triphosphate (ATP). P2 × 4Rs are expressed throughout the central nervous system including the dopaminergic circuitry of the substantia nigra, basal ganglia, and related reward networks. Previous studies have demonstrated that P2 × 4Rs can modulate several DA-dependent characteristics including motor, cognitive, and reward behaviors. Ivermectin (IVM) and moxidectin (MOX) are two macrocyclic lactones that can potentiate P2 × 4Rs. In this study, we sought to investigate the role of P2 × 4Rs in mediating DA neurotransmission by exploring their impact on DA-dependent behavior, specifically rotation frequency in the unilateral 6-hydroxydopamine-lesioned mouse model of DA-depletion. While we did not observe any differences in the degree of lesioning based on immunostaining for tyrosine hydroxylase between sexes, male mice displayed a greater number of rotations with L-DOPA compared to female mice. In contrast, we observed that IVM plus L-DOPA increased the number of rotations (per 10 min) in female, but not male mice. These findings highlight the potential role of pharmacologically targeting the purinergic receptor system in modulating DA neurotransmission as well as the importance of sex differences impacting outcome measures.
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Affiliation(s)
- Alicia M P Warnecke
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Moon S Kang
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Michael W Jakowec
- Department of Neurology, Keck School of Medicine, University of Southern California, 1333 San Pablo Street, Los Angeles, CA 90033, USA
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA.
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El-Saber Batiha G, Alqahtani A, Ilesanmi OB, Saati AA, El-Mleeh A, Hetta HF, Magdy Beshbishy A. Avermectin Derivatives, Pharmacokinetics, Therapeutic and Toxic Dosages, Mechanism of Action, and Their Biological Effects. Pharmaceuticals (Basel) 2020; 13:ph13080196. [PMID: 32824399 PMCID: PMC7464486 DOI: 10.3390/ph13080196] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/09/2020] [Accepted: 08/13/2020] [Indexed: 12/15/2022] Open
Abstract
Avermectins are a group of drugs that occurs naturally as a product of fermenting Streptomyces avermitilis, an actinomycetes, isolated from the soil. Eight different structures, including ivermectin, abamectin, doramectin, eprinomectin, moxidectin, and selamectin, were isolated and divided into four major components (A1a, A2a, B1a and B2a) and four minor components (A1b, A2b, B1b, and B2b). Avermectins are generally used as a pesticide for the treatment of pests and parasitic worms as a result of their anthelmintic and insecticidal properties. Additionally, they possess anticancer, anti-diabetic, antiviral, antifungal, and are used for treatment of several metabolic disorders. Avermectin generally works by preventing the transmission of electrical impulse in the muscle and nerves of invertebrates, by amplifying the glutamate effects on the invertebrates-specific gated chloride channel. Avermectin has unwanted effects or reactions, especially when administered indiscriminately, which include respiratory failure, hypotension, and coma. The current review examines the mechanism of actions, biosynthesis, safety, pharmacokinetics, biological toxicity and activities of avermectins.
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Affiliation(s)
- Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour 22511, Egypt
- Correspondence: or (G.E.-S.B.); (A.M.B.)
| | - Ali Alqahtani
- Department of Pharmacology, College of Pharmacy, King Khalid University, Guraiger, Abha 62529, Saudi Arabia;
| | - Omotayo B. Ilesanmi
- Department of Biochemistry, Faculty of Science, Federal University Otuoke, Otuoke 561, Nigeria;
| | - Abdullah A. Saati
- Department of Community Medicine & Pilgrims Healthcare, Faculty of Medicine, Umm Al-Qura University Makkah, Mecca 24382, Saudi Arabia;
| | - Amany El-Mleeh
- Department of Pharmacology, Faculty of Veterinary Medicine, Menoufia University, Shibin Al Kawm 32511, Egypt;
| | - Helal F. Hetta
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut 71515, Egypt;
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45221, USA
| | - Amany Magdy Beshbishy
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-13, Inada-cho, Obihiro 080-8555, Hokkaido, Japan
- Correspondence: or (G.E.-S.B.); (A.M.B.)
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12
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Silva J, Khoja S, Asatryan L, Pacifici E, Davies DL. A novel pharmacotherapy approach using P-glycoprotein (PGP/ABCB1) efflux inhibitor combined with ivermectin to reduce alcohol drinking and preference in mice. Alcohol 2020; 86:1-8. [PMID: 32278067 DOI: 10.1016/j.alcohol.2020.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/25/2020] [Accepted: 03/25/2020] [Indexed: 01/12/2023]
Abstract
Alcohol use disorder (AUD) has a major national impact, affecting over 18 million people, causing approximately 88,000 deaths, and costing upward of $250 billion annually in the United States. Unfortunately, FDA-approved AUD pharmaceuticals are few, and clinical benefits are mostly ineffective in patients suffering from AUD. Therefore, the identification of novel targets and/or innovative methods for the development of safe and effective medications represents a critical public health need. Previously, we reported that avermectin compounds (ivermectin [IVM] and moxidectin [MOX]) significantly reduced ethanol intake in male and female mice. However, avermectin compounds are readily effluxed by P-glycoprotein (Pgp/ABCB1) in the blood-brain barrier (BBB), resulting in reduced retention time by the drugs in the central nervous system (CNS). As such, the doses of IVM or MOX and the time frame for significant reductions of ethanol intake are not ideal. Here we evaluate a novel combinatorial strategy involving IVM and tariquidar (TQ), a third-generation efflux inhibitor of Pgp, to reduce the dosing necessary for improving alcohol (ethanol) consumption behavior. We tested male C57BL/6J mice using a two-bottle choice study to evaluate ethanol consumption and preference. We found that injecting 10 mg/kg of TQ 30 min prior to IVM resulted in a five-fold improvement in the efficacy of IVM (dosed at 0.5 mg/kg), resulting in a significant reduction in ethanol intake and preference. Notably, the reduction by IVM was well tolerated, and no adverse effects were identified when tested at doses ranging from 0.50 mg/kg to 2.0 mg/kg. Collectively, our findings indicate that IVM, in combination with TQ, increases its efficacy in the CNS for reducing ethanol consumption. This work demonstrates a novel combinatorial drug strategy that allows new opportunities for drugs with poor CNS retention, such as IVM, to demonstrate improved potency and potentially improved safety.
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13
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Stokes L, Bidula S, Bibič L, Allum E. To Inhibit or Enhance? Is There a Benefit to Positive Allosteric Modulation of P2X Receptors? Front Pharmacol 2020; 11:627. [PMID: 32477120 PMCID: PMC7235284 DOI: 10.3389/fphar.2020.00627] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 04/21/2020] [Indexed: 12/15/2022] Open
Abstract
The family of ligand-gated ion channels known as P2X receptors were discovered several decades ago. Since the cloning of the seven P2X receptors (P2X1-P2X7), a huge research effort has elucidated their roles in regulating a range of physiological and pathophysiological processes. Transgenic animals have been influential in understanding which P2X receptors could be new therapeutic targets for disease. Furthermore, understanding how inherited mutations can increase susceptibility to disorders and diseases has advanced this knowledge base. There has been an emphasis on the discovery and development of pharmacological tools to help dissect the individual roles of P2X receptors and the pharmaceutical industry has been involved in pushing forward clinical development of several lead compounds. During the discovery phase, a number of positive allosteric modulators have been described for P2X receptors and these have been useful in assigning physiological roles to receptors. This review will consider the major physiological roles of P2X1-P2X7 and discuss whether enhancement of P2X receptor activity would offer any therapeutic benefit. We will review what is known about identified compounds acting as positive allosteric modulators and the recent identification of drug binding pockets for such modulators.
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Affiliation(s)
- Leanne Stokes
- School of Pharmacy, University of East Anglia, Norwich, United Kingdom
| | - Stefan Bidula
- School of Pharmacy, University of East Anglia, Norwich, United Kingdom
| | - Lučka Bibič
- School of Pharmacy, University of East Anglia, Norwich, United Kingdom
| | - Elizabeth Allum
- School of Pharmacy, University of East Anglia, Norwich, United Kingdom
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14
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Jacob A, Wang P. Alcohol Intoxication and Cognition: Implications on Mechanisms and Therapeutic Strategies. Front Neurosci 2020; 14:102. [PMID: 32116535 PMCID: PMC7029710 DOI: 10.3389/fnins.2020.00102] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/27/2020] [Indexed: 12/23/2022] Open
Abstract
Binge alcohol drinking is highly prevalent in young adults and results in 30% deaths per year in young males. Binge alcohol drinking or acute alcohol intoxication is a risk factor for developing alcohol use disorder (AUD). Three FDA approved drugs are currently in use as therapy for AUD; however, all of them have contra-indications and limitations. Structural brain imaging studies in alcoholics have shown defects in the brain regions involved in memory, cognition and emotional processing. Positron emission tomography (PET) using radiotracers (e.g., 18FDG) and measuring brain glucose metabolism have demonstrated diagnostic and prognostic utility in evaluating patients with cognitive impairment. Using PET imaging, only a few exclusive human studies have addressed the relationship between alcohol intoxication and cognition. Those studies indicate that alcohol intoxication causes reduction in brain activity. Consistent with prior findings, a recent study by us showed that acute alcohol intoxication reduced brain activity in the cortical and subcortical regions including the temporal lobe consisting the hippocampus. Additionally, we have observed a strong correlation between reduction in metabolic activity and spatial cognition impairment in the hippocampus after binge alcohol exposure. We have also demonstrated the involvement of a stress response protein, cold inducible RNA binding protein (CIRP), as a potential mechanistic mediator in acute alcohol intoxication. In this review, we will first discuss in detail prior human PET imaging studies on alcohol intoxication as well as our recent study on acute alcohol intoxication, and review the existing literature on potential mechanisms of acute alcohol intoxication-induced cognitive impairment and therapeutic strategies to mitigate these impairments. Finally, we will highlight the importance of studying brain regions as part of a brain network in delineating the mechanism of acute alcohol intoxication-induced cognitive impairment to aid in the development of therapeutics for such indication.
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Affiliation(s)
- Asha Jacob
- Center for Immunology and Inflammation, The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
- Department of Molecular Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States
| | - Ping Wang
- Center for Immunology and Inflammation, The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
- Department of Molecular Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States
- Department of Surgery, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States
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15
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Lowe PP, Cho Y, Tornai D, Coban S, Catalano D, Szabo G. Inhibition of the Inflammasome Signaling Cascade Reduces Alcohol Consumption in Female But Not Male Mice. Alcohol Clin Exp Res 2020; 44:567-578. [PMID: 31854009 DOI: 10.1111/acer.14272] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 12/10/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND Alcohol use disorder is a significant societal and medical burden that is associated with both organ pathology and addiction. Excessive alcohol use results in neuroinflammation characterized by activation of the inflammasome, a multiprotein complex, and IL-1β increase in the brain. Recent studies suggest that inflammation could contribute to alcohol addiction. Here, we targeted components of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome cascade, which senses and responds to immunologic stimuli, to determine whether NLRP3 inhibition modulates alcohol consumption. METHODS C57BL/6J male and female mice were provided a 2-bottle choice of alcohol at increasing concentrations (3, 6, 9, and 12%, 4 days each) or water, and some were treated with daily injections of an NLRP3 inhibitor (MCC950), a caspase-1 inhibitor (VX765), IL-1 receptor antagonist (IL-1ra; anakinra), or vehicle injection. RESULTS Treatment with VX765, MCC950, and IL-1ra significantly reduced alcohol consumption and preference in female mice (p < 0.05). Treatment with MCC950 and IL-1ra reduced alcohol consumption, while IL-1ra reduced alcohol preference in male mice (p < 0.05). VX765 did not affect alcohol consumption or preference in male mice. CONCLUSIONS These findings highlight gender differences in alcohol preference and demonstrate that inhibition of different steps in inflammasome signaling can reduce alcohol consumption in females. Inhibition of NLRP3 inflammasome activation and the inflammasome-IL-1β cascade opens novel insights into the development of new therapies to address alcohol use disorder in an era of targeted and precision medicine.
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Affiliation(s)
- Patrick P Lowe
- From the, Department of Medicine, (PPL, YC, DT, SC, DC, GS), University of Massachusetts Medical School, Worcester, Massachusetts
| | - Yeonhee Cho
- From the, Department of Medicine, (PPL, YC, DT, SC, DC, GS), University of Massachusetts Medical School, Worcester, Massachusetts.,Beth Israel Deaconess Medical Center, (YC, DT, GS), Harvard Medical School, Boston, Massachusetts
| | - David Tornai
- From the, Department of Medicine, (PPL, YC, DT, SC, DC, GS), University of Massachusetts Medical School, Worcester, Massachusetts.,Beth Israel Deaconess Medical Center, (YC, DT, GS), Harvard Medical School, Boston, Massachusetts
| | - Sahin Coban
- From the, Department of Medicine, (PPL, YC, DT, SC, DC, GS), University of Massachusetts Medical School, Worcester, Massachusetts
| | - Donna Catalano
- From the, Department of Medicine, (PPL, YC, DT, SC, DC, GS), University of Massachusetts Medical School, Worcester, Massachusetts
| | - Gyongyi Szabo
- From the, Department of Medicine, (PPL, YC, DT, SC, DC, GS), University of Massachusetts Medical School, Worcester, Massachusetts.,Beth Israel Deaconess Medical Center, (YC, DT, GS), Harvard Medical School, Boston, Massachusetts
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16
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Neurochemical Evidence of Preclinical and Clinical Reports on Target-Based Therapy in Alcohol Used Disorder. Neurochem Res 2020; 45:491-507. [PMID: 31898084 DOI: 10.1007/s11064-019-02944-9] [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: 10/23/2019] [Revised: 12/13/2019] [Accepted: 12/20/2019] [Indexed: 10/25/2022]
Abstract
Alcohol use disorder (AUD) is a chronic relapsing disorder, which enforces a person to compulsively seek alcohol, restricting control over alcohol intake leads to emergence of an undesired emotional state during abstinence. There are recent advances for better understanding of neurocircuitry involved in the pathophysiology of AUD. Alcohol interaction with neuronal membrane proteins results in changes in neuronal circuits. It is also linked with the potential medication and their clinical validation concerning their pharmacological targets for alcoholic abstinence. This review covers research work from the past few decades on the therapeutic advances on treatment of alcohol dependence; further detailing the fundamental neurochemical mechanisms after alcohol administration. It also covers interaction of alcohol with GABAergic, glutaminergic, dopaminergic, serotonergic and opioid systems. This review further elaborated the neurobiology of noradrenergic, cholinergic and cannabinoid systems and their interaction with AUD. Elaborative information of potential drug targets under current exploration for AUD treatment with their mechanisms are reported here along with clinical outcomes and the associated side effects.
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17
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Paalme V, Rump A, Mädo K, Teras M, Truumees B, Aitai H, Ratas K, Bourge M, Chiang CS, Ghalali A, Tordjmann T, Teras J, Boudinot P, Kanellopoulos JM, Rüütel Boudinot S. Human Peripheral Blood Eosinophils Express High Levels of the Purinergic Receptor P2X4. Front Immunol 2019; 10:2074. [PMID: 31552031 PMCID: PMC6746186 DOI: 10.3389/fimmu.2019.02074] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 08/16/2019] [Indexed: 12/14/2022] Open
Abstract
Extracellular nucleotides are important mediators of cell activation and trigger multiple responses via membrane receptors known as purinergic receptors (P2). P2X receptors are ligand-gated ion channels, activated by extracellular ATP. P2X4 is one of the most sensitive purinergic receptors, that is typically expressed by neurons, microglia, and some epithelial and endothelial cells. P2X4 mediates neuropathic pain via brain-derived neurotrophic factor and is also involved in inflammation in response to high ATP release. It is therefore involved in multiple inflammatory pathologies as well as neurodegenerative diseases. We have produced monoclonal antibodies (mAb) directed against this important human P2X4 receptor. Focusing on two mAbs, we showed that they also recognize mouse and rat P2X4. We demonstrated that these mAbs can be used in flow cytometry, immunoprecipitation, and immunohistochemistry, but not in Western blot assays, indicating that they target conformational epitopes. We also characterized the expression of P2X4 receptor on mouse and human peripheral blood lymphocytes (PBL). We showed that P2X4 is expressed at the surface of several leukocyte cell types, with the highest expression level on eosinophils, making them potentially sensitive to adenosine triphosphate (ATP). P2X4 is expressed by leucocytes, in human and mouse, with a significant gender difference, males having higher surface expression levels than females. Our findings reveal that PBL express significant levels of P2X4 receptor, and suggest an important role of this receptor in leukocyte activation by ATP, particularly in P2X4high expressing eosinophils.
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Affiliation(s)
- Viiu Paalme
- Immunology Unit, Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Airi Rump
- Immunology Unit, Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Kati Mädo
- North Estonia Medical Centre Foundation, Tallinn, Estonia
| | - Marina Teras
- North Estonia Medical Centre Foundation, Tallinn, Estonia
| | | | - Helen Aitai
- Immunology Unit, Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Kristel Ratas
- Immunology Unit, Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Mickael Bourge
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Chi-Shiun Chiang
- Department of Biomedical Engineering and Environmental Sciences, and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing-Hua University, Hsinchu, Taiwan
| | - Aram Ghalali
- Institute of Environment Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Jüri Teras
- North Estonia Medical Centre Foundation, Tallinn, Estonia
| | - Pierre Boudinot
- Virologie et Immunologie Moléculaires, INRA, Université Paris Saclay, Jouy en Josas, France
| | - Jean M Kanellopoulos
- Department of Biochemistry Biophysics and Structural Biology, I2BC-CNRS, Université Paris-Sud, Orsay, France
| | - Sirje Rüütel Boudinot
- Immunology Unit, Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
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18
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Melbourne JK, Thompson KR, Peng H, Nixon K. Its complicated: The relationship between alcohol and microglia in the search for novel pharmacotherapeutic targets for alcohol use disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 167:179-221. [PMID: 31601404 DOI: 10.1016/bs.pmbts.2019.06.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alcohol use disorder (AUD) is a chronic relapsing disorder with wide-ranging health consequences. Alcohol targets the central nervous system producing neurodegeneration and subsequent cognitive and behavioral deficits, but the mechanisms behind these effects remain unclear. Recently, evidence has been mounting for the role of neuroimmune activation in the pathogenesis of AUDs, but our nascent state of knowledge about the interaction of alcohol with the neuroimmune system supports that the relationship is complicated. As the resident macrophage of the central nervous system, microglia are a central focus. Human and animal research on the interplay between microglia and alcohol in AUDs has proven to be complex, and though early research focused on a pro-inflammatory phenotype of microglia, the anti-inflammatory and homeostatic roles of microglia must be considered. How these new roles for microglia should be incorporated into our thinking about the neuroimmune system in AUDs is discussed in the context of developing novel pharmacotherapies for AUDs.
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Affiliation(s)
- Jennifer K Melbourne
- The University of Texas at Austin, College of Pharmacy, Division of Pharmacology & Toxicology, Austin, TX, United States
| | - K Ryan Thompson
- The University of Texas at Austin, College of Pharmacy, Division of Pharmacology & Toxicology, Austin, TX, United States
| | - Hui Peng
- University of Kentucky, College of Pharmacy, Department of Pharmaceutical Sciences, Lexington, KY, United States
| | - Kimberly Nixon
- The University of Texas at Austin, College of Pharmacy, Division of Pharmacology & Toxicology, Austin, TX, United States.
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19
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Khoja S, Asatryan L, Jakowec MW, Davies DL. Dopamine Receptor Blockade Attenuates Purinergic P2X4 Receptor-Mediated Prepulse Inhibition Deficits and Underlying Molecular Mechanisms. Front Cell Neurosci 2019; 13:331. [PMID: 31396053 PMCID: PMC6664007 DOI: 10.3389/fncel.2019.00331] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 07/04/2019] [Indexed: 11/13/2022] Open
Abstract
Sensorimotor gating refers to the ability to filter incoming sensory information in a stimulus-laden environment and disruption of this physiological process has been documented in psychiatric disorders characterized by cognitive aberrations. The effectiveness of current pharmacotherapies for treatment of sensorimotor gating deficits in the patient population still remains controversial. These challenges emphasize the need to better understand the biological underpinnings of sensorimotor gating which could lead to discovery of novel drug targets for therapeutic intervention. Notably, we recently reported a role for purinergic P2X4 receptors (P2X4Rs) in regulation of sensorimotor gating using prepulse inhibition (PPI) of acoustic startle reflex. P2X4Rs are ion channels gated by adenosine-5′-triphosphate (ATP). Ivermectin (IVM) induced PPI deficits in C57BL/6J mice in a P2X4R-specific manner. Furthermore, mice deficient in P2X4Rs [P2X4R knockout (KO)] exhibited PPI deficits that were alleviated by dopamine (DA) receptor antagonists demonstrating an interaction between P2X4Rs and DA receptors in PPI regulation. On the basis of these findings, we hypothesized that increased DA neurotransmission underlies IVM-mediated PPI deficits. To test this hypothesis, we measured the effects of D1 and D2 receptor antagonists, SCH 23390 and raclopride respectively and D1 agonist, SKF 82958 on IVM-mediated PPI deficits. To gain mechanistic insights, we investigated the interaction between IVM and dopaminergic drugs on signaling molecules linked to PPI regulation in the ventral striatum. SCH 23390 significantly attenuated the PPI disruptive effects of IVM to a much greater degree than that of raclopride. SKF 82958 failed to potentiate IVM-mediated PPI disruption. At the molecular level, modulation of D1 receptors altered IVM’s effects on dopamine and cyclic-AMP regulated phosphoprotein of 32 kDa (DARPP-32) phosphorylation. Additionally, IVM interacted with the DA receptors antagonists and SKF 82958 in phosphorylation of Ca2+/calmodulin kinase IIα (CaMKIIα) and its downstream target, neuronal nitric oxide synthase (nNOS). Current findings suggest an involvement for D1 and D2 receptors in IVM-mediated PPI disruption via modulation of DARPP-32, CaMKIIα and nNOS. Taken together, the findings suggest that stimulation of P2X4Rs can lead to DA hyperactivity and disruption of information processing, implicating P2X4Rs as a novel drug target for treatment of psychiatric disorders characterized by sensorimotor gating deficits.
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Affiliation(s)
- Sheraz Khoja
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Michael W Jakowec
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
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20
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Huynh N, Arabian NM, Asatryan L, Davies DL. Murine Drinking Models in the Development of Pharmacotherapies for Alcoholism: Drinking in the Dark and Two-bottle Choice. J Vis Exp 2019. [PMID: 30663649 DOI: 10.3791/57027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Alcohol Use Disorder (AUD) is a major problem with more than an estimated 76 million people worldwide meeting the diagnostic criteria. Current treatments are limited to three FDA-approved medications that are largely ineffective even when combined with psychosocial intervention, as is evident by the high relapse rate. As such, the search for more novel treatments represents an important public health goal. To this end, the following protocol utilizes two simple rodent drinking models to assess the preclinical efficacy of lead anti-alcohol compounds: two-bottle choice (TBC) and drinking in the dark (DID). The former allows mice to voluntary drink in moderation while the latter induces mice to voluntary consume a large amount of alcohol in a short period that mimics binge drinking. The simple and high throughput nature of both of these paradigms allow for rapid screening of pharmacological agents or for identifying strains of mice that exhibit certain voluntary drinking behavior.
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Affiliation(s)
- Nhat Huynh
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, School of Pharmacy, University of Southern California
| | - Natalie M Arabian
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, School of Pharmacy, University of Southern California
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, School of Pharmacy, University of Southern California
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, School of Pharmacy, University of Southern California;
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21
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Dhuna K, Felgate M, Bidula SM, Walpole S, Bibic L, Cromer BA, Angulo J, Sanderson J, Stebbing MJ, Stokes L. Ginsenosides Act As Positive Modulators of P2X4 Receptors. Mol Pharmacol 2018; 95:210-221. [PMID: 30545933 PMCID: PMC6334005 DOI: 10.1124/mol.118.113696] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 12/10/2018] [Indexed: 12/19/2022] Open
Abstract
We investigated the selectivity of protopanaxadiol ginsenosides from Panax ginseng acting as positive allosteric modulators on P2X receptors. ATP-induced responses were measured in stable cell lines overexpressing human P2X4 using a YOPRO-1 dye uptake assay, intracellular calcium measurements, and whole-cell patch-clamp recordings. Ginsenosides CK and Rd were demonstrated to enhance ATP responses at P2X4 by ∼twofold, similar to potentiation by the known positive modulator ivermectin. Investigations into the role of P2X4 in mediating a cytotoxic effect showed that only P2X7 expression in HEK-293 cells induces cell death in response to high concentrations of ATP, and that ginsenosides can enhance this process. Generation of a P2X7-deficient clone of BV-2 microglial cells using CRISPR/Cas9 gene editing enabled an investigation of endogenous P2X4 in a microglial cell line. Compared with parental BV-2 cells, P2X7-deficient BV-2 cells showed minor potentiation of ATP responses by ginsenosides, and insensitivity to ATP− or ATP+ ginsenoside-induced cell death, indicating a primary role for P2X7 receptors in both of these effects. Computational docking to a homology model of human P2X4, based on the open state of zfP2X4, yielded evidence of a putative ginsenoside binding site in P2X4 in the central vestibule region of the large ectodomain.
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Affiliation(s)
- Kshitija Dhuna
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
| | - Matthew Felgate
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
| | - Stefan M Bidula
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
| | - Samuel Walpole
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
| | - Lucka Bibic
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
| | - Brett A Cromer
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
| | - Jesus Angulo
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
| | - Julie Sanderson
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
| | - Martin J Stebbing
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
| | - Leanne Stokes
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia (K.D., B.A.C., M.J.S., L.S.); School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom (M.F., S.M.B., S.W., L.B., J.A., J.S., L.S.); Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia (B.A.C.); and Florey Institute of Neuroscience and Mental Health, Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia (M.J.S.)
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Khoja S, Huynh N, Warnecke AMP, Asatryan L, Jakowec MW, Davies DL. Preclinical evaluation of avermectins as novel therapeutic agents for alcohol use disorders. Psychopharmacology (Berl) 2018; 235:1697-1709. [PMID: 29500584 PMCID: PMC5949264 DOI: 10.1007/s00213-018-4869-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 02/20/2018] [Indexed: 12/23/2022]
Abstract
The deleterious effects of alcohol use disorders (AUDs) on human health have been documented worldwide. The enormous socioeconomic burden coupled with lack of efficacious pharmacotherapies underlies the need for improved treatment strategies. At present, there is a growing body of preclinical evidence that demonstrates the potential of avermectins [ivermectin (IVM), selamectin (SEL), abamectin (ABM), and moxidectin (MOX)] in treatment of AUDs. Avermectins are derived by fermentation of soil micro-organism, Streptomyces avermitilis, and have been extensively used for treatment of parasitic infections. From the mechanistic standpoint, avermectins are positive modulators of purinergic P2X4 receptors (P2X4Rs). P2X4Rs belong to P2X superfamily of cation-permeable ion channels gated by adenosine 5'-triphosphate (ATP). Building evidence has implicated a role for P2X4Rs in regulation of ethanol intake and that ethanol can inhibit ATP-gated currents in P2X4Rs. Investigations using recombinant cell models and animal models of alcohol drinking have reported that IVM, ABM, and MOX, but not SEL, were able to antagonize the inhibitory effects of ethanol on P2X4Rs in vitro and reduce ethanol intake in vivo. Furthermore, IVM was shown to reduce ethanol consumption via P2X4R potentiation in vivo, supporting the involvement of P2X4Rs in IVM's anti-alcohol effects and that P2X4Rs can be used as a platform for developing novel anti-alcohol compounds. Taken together, these findings support the utility of avermectins as a novel class of drug candidates for treatment of AUDs.
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Affiliation(s)
- Sheraz Khoja
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90089, USA
| | - Nhat Huynh
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90089, USA
| | - Alicia M P Warnecke
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90089, USA
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90089, USA
| | - Michael W Jakowec
- Department of Neurology, Keck School of Medicine, University of Southern California, 1975 Zonal Avenue, Los Angeles, CA, 90033, USA
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90089, USA.
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Ch’Ng SS, Lawrence AJ. Investigational drugs for alcohol use disorders: a review of preclinical data. Expert Opin Investig Drugs 2018; 27:459-474. [DOI: 10.1080/13543784.2018.1472763] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Sarah S Ch’Ng
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Andrew J Lawrence
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
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24
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Khoja S, Huynh N, Asatryan L, Jakowec MW, Davies DL. Reduced expression of purinergic P2X4 receptors increases voluntary ethanol intake in C57BL/6J mice. Alcohol 2018; 68:63-70. [PMID: 29477921 DOI: 10.1016/j.alcohol.2017.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 09/24/2017] [Accepted: 09/26/2017] [Indexed: 12/30/2022]
Abstract
Purinergic P2X4 receptors (P2X4Rs) belong to the P2X superfamily of ionotropic receptors that are gated by adenosine 5'-triphosphate (ATP). Accumulating evidence indicates that P2X4Rs play an important role in regulation of ethanol intake. At the molecular level, ethanol's inhibitory effects on P2X4Rs are antagonized by ivermectin (IVM), in part, via action on P2X4Rs. Behaviorally, male mice deficient in the p2rx4 gene (P2X4R knockout [KO]) have been shown to exhibit a transient increase in ethanol intake over a period of 4 days, as demonstrated by social and binge drinking paradigms. Furthermore, IVM reduced ethanol consumption in male and female rodents, whereas male P2X4R KO mice were less sensitive to the anti-alcohol effects of IVM, compared to wildtype (WT) mice, further supporting a role for P2X4Rs as targets of IVM's action. The current investigation extends testing the hypothesis that P2X4Rs play a role in regulation of ethanol intake. First, we tested the response of P2X4R KO mice to ethanol for a period of 5 weeks. Second, to gain insights into the changes in ethanol intake, we employed a lentivirus-shRNA (LV-shRNA) methodology to selectively knockdown P2X4R expression in the nucleus accumbens (NAc) core in male C57BL/6J mice. In agreement with our previous study, male P2X4R KO mice exhibited higher ethanol intake than WT mice. Additionally, reduced expression of P2X4Rs in the NAc core significantly increased ethanol intake and preference. Collectively, the findings support the hypothesis that P2X4Rs play a role in regulation of ethanol intake and that P2X4Rs represent a novel drug target for treatment of alcohol use disorder.
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Affiliation(s)
- Sheraz Khoja
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, United States
| | - Nhat Huynh
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, United States
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, United States
| | - Michael W Jakowec
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, United States
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, United States.
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Abstract
Patients who suffer from alcohol use disorders (AUDs) usually go through various socio-behavioral and pathophysiological changes that take place in the brain and other organs. Recently, consumption of unhealthy food and excess alcohol along with a sedentary lifestyle has become a norm in both developed and developing countries. Despite the beneficial effects of moderate alcohol consumption, chronic and/or excessive alcohol intake is reported to negatively affect the brain, liver and other organs, resulting in cell death, organ damage/failure and death. The most effective therapy for alcoholism and alcohol related comorbidities is alcohol abstinence, however, chronic alcoholic patients cannot stop drinking alcohol. Therefore, targeted therapies are urgently needed to treat such populations. Patients who suffer from alcoholism and/or alcohol abuse experience harmful effects and changes that occur in the brain and other organs. Upon stopping alcohol consumption, alcoholic patients experience acute withdrawal symptoms followed by a protracted abstinence syndrome resulting in the risk of relapse to heavy drinking. For the past few decades, several drugs have been available for the treatment of AUDs. These drugs include medications to reduce or stop severe alcohol withdrawal symptoms during alcohol detoxification as well as recovery medications to reduce alcohol craving and support abstinence. However, there is no drug that completely antagonizes the adverse effects of excessive amounts of alcohol. This review summarizes the drugs which are available and approved by the FDA and their mechanisms of action as well as the medications that are under various phases of preclinical and clinical trials. In addition, the repurposing of the FDA approved drugs, such as anticonvulsants, antipsychotics, antidepressants and other medications, to prevent alcoholism and treat AUDs and their potential target mechanisms are summarized.
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Affiliation(s)
- Mohammed Akbar
- Division of Neuroscience and Behavior, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA.
| | - Mark Egli
- Division of Neuroscience and Behavior, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA
| | - Young-Eun Cho
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA
| | - Byoung-Joon Song
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA
| | - Antonio Noronha
- Division of Neuroscience and Behavior, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA
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26
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Suurväli J, Boudinot P, Kanellopoulos J, Rüütel Boudinot S. P2X4: A fast and sensitive purinergic receptor. Biomed J 2017; 40:245-256. [PMID: 29179879 PMCID: PMC6138603 DOI: 10.1016/j.bj.2017.06.010] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 06/28/2017] [Accepted: 06/30/2017] [Indexed: 01/31/2023] Open
Abstract
Extracellular nucleotides have been recognized as important mediators of activation, triggering multiple responses via plasma membrane receptors known as P2 receptors. P2 receptors comprise P2X ionotropic receptors and G protein-coupled P2Y receptors. P2X receptors are expressed in many tissues, where they are involved in a number of functions including synaptic transmission, muscle contraction, platelet aggregation, inflammation, macrophage activation, differentiation and proliferation, neuropathic and inflammatory pain. P2X4 is one of the most sensitive purinergic receptors (at nanomolar ATP concentrations), about one thousand times more than the archetypal P2X7. P2X4 is widely expressed in central and peripheral neurons, in microglia, and also found in various epithelial tissues and endothelial cells. It localizes on the plasma membrane, but also in intracellular compartments. P2X4 is preferentially localized in lysosomes, where it is protected from proteolysis by its glycosylation. High ATP concentration in the lysosomes does not activate P2X4 at low pH; P2X4 gets activated by intra-lysosomal ATP only in its fully dissociated tetra-anionic form, when the pH increases to 7.4. Thus, P2X4 is functioning as a Ca2+-channel after the fusion of late endosomes and lysosomes. P2X4 modulates major neurotransmitter systems and regulates alcohol-induced responses in microglia. P2X4 is one of the key receptors mediating neuropathic pain. However, injury-induced upregulation of P2X4 expression is gender dependent and plays a key role in pain difference between males and females. P2X4 is also involved in inflammation. Extracellular ATP being a pro-inflammatory molecule, P2X4 can trigger inflammation in response to high ATP release. It is therefore involved in multiple pathologies, like post-ischemic inflammation, rheumatoid arthritis, airways inflammation in asthma, neurodegenerative diseases and even metabolic syndrome. Although P2X4 remains poorly characterized, more studies are needed as it is likely to be a potential therapeutic target in these multiple pathologies.
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Affiliation(s)
- Jaanus Suurväli
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Pierre Boudinot
- Virologie et Immunologie Moléculaires, INRA, Université Paris-Saclay, Jouy-en-Josas, France
| | - Jean Kanellopoulos
- Institute for Integrative Biology of the Cell (I2BC) CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette cedex, France
| | - Sirje Rüütel Boudinot
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia.
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Asatryan L, Ostrovskaya O, Lieu D, Davies DL. Ethanol differentially modulates P2X4 and P2X7 receptor activity and function in BV2 microglial cells. Neuropharmacology 2017; 128:11-21. [PMID: 28943285 DOI: 10.1016/j.neuropharm.2017.09.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 09/05/2017] [Accepted: 09/21/2017] [Indexed: 01/02/2023]
Abstract
Neuroinflammation is one of the mechanisms leading to neurodegenerative brain damage induced by chronic alcohol (ethanol) exposure. Microglia play a major role in the development of innate immune responses to environmental injuries including ethanol. Adenosine 5″-triphosphate (ATP)-activated purinergic P2X receptor (P2XR) subtypes, P2X4Rs and P2X7Rs, are endogenously expressed in microglia and can modulate their activity. These 2 P2XR subtypes differ pharmacologically and functionally: 1) P2X4Rs are activated at lower (≤0.1 mM) whereas P2X7Rs - at higher (≥1.0 mM) ATP concentrations; 2) P2X4R activation contributes to the release of brain derived neurotrophic factor and its role in tactile allodynia and neuropathic pain is demonstrated; 3) Due to its role in the secretion of pro-inflammatory IL-1β, P2X7Rs have been implicated in the development of neurodegenerative pathologies, pain and morphine tolerance. To date, the roles of individual P2XR subtypes in ethanol effects on microglia and the functional consequences are not completely understood. Based on the existing knowledge on the pharmacological and functional differences between P2X4Rs and P2X7Rs, the present work tested the hypothesis that P2X4Rs and P2X7Rs play differential roles in ethanol action in microglia. Effects of ethanol on P2X4R and P2X7R activity, expression and functional consequences were determined using murine BV2 microglial cells. Ethanol (≥100 mM) inhibited P2X4Rs but was inactive on P2X7 channel activity. Ethanol (25, 100 mM) inhibited P2X4R-mediated microglia migration whereas it potentiated pore formation in P2X7Rs. Furthermore, ethanol (25, 100 mM) potentiated P2X7R-mediated IL-1β secretion from BV2 microglia. Ethanol also induced protein expression for both P2XR subtypes. Overall, the findings identify differential roles for P2X4Rs and P2X7Rs in regards to ethanol effects on microglia which may be linked to different stages of ethanol exposure.
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Affiliation(s)
- Liana Asatryan
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, United States.
| | - Olga Ostrovskaya
- Center for Learning and Memory, University of Texas at Austin, Austin, TX 78712, United States
| | - Dustin Lieu
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, United States
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, United States
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28
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Stokes L, Layhadi JA, Bibic L, Dhuna K, Fountain SJ. P2X4 Receptor Function in the Nervous System and Current Breakthroughs in Pharmacology. Front Pharmacol 2017; 8:291. [PMID: 28588493 PMCID: PMC5441391 DOI: 10.3389/fphar.2017.00291] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/05/2017] [Indexed: 12/18/2022] Open
Abstract
Adenosine 5′-triphosphate is a well-known extracellular signaling molecule and neurotransmitter known to activate purinergic P2X receptors. Information has been elucidated about the structure and gating of P2X channels following the determination of the crystal structure of P2X4 (zebrafish), however, there is still much to discover regarding the role of this receptor in the central nervous system (CNS). In this review we provide an overview of what is known about P2X4 expression in the CNS and discuss evidence for pathophysiological roles in neuroinflammation and neuropathic pain. Recent advances in the development of pharmacological tools including selective antagonists (5-BDBD, PSB-12062, BX430) and positive modulators (ivermectin, avermectins, divalent cations) of P2X4 will be discussed.
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Affiliation(s)
- Leanne Stokes
- School of Pharmacy, University of East Anglia, Norwich Research ParkNorwich, United Kingdom.,School of Biomedical and Health Sciences, RMIT University, BundooraVIC, Australia
| | - Janice A Layhadi
- Biomedical Research Centre, School of Biological Sciences, University of East AngliaNorwich, United Kingdom
| | - Lucka Bibic
- School of Pharmacy, University of East Anglia, Norwich Research ParkNorwich, United Kingdom
| | - Kshitija Dhuna
- School of Biomedical and Health Sciences, RMIT University, BundooraVIC, Australia
| | - Samuel J Fountain
- Biomedical Research Centre, School of Biological Sciences, University of East AngliaNorwich, United Kingdom
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29
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Yardley MM, Ray LA. Medications development for the treatment of alcohol use disorder: insights into the predictive value of animal and human laboratory models. Addict Biol 2017; 22:581-615. [PMID: 26833803 DOI: 10.1111/adb.12349] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 11/09/2015] [Accepted: 11/13/2015] [Indexed: 12/20/2022]
Abstract
Development of effective treatments for alcohol use disorder (AUD) represents an important public health goal. This review provides a summary of completed preclinical and clinical studies testing pharmacotherapies for the treatment of AUD. We discuss opportunities for improving the translation from preclinical findings to clinical trial outcomes, focusing on the validity and predictive value of animal and human laboratory models of AUD. Specifically, while preclinical studies of medications development have offered important insights into the neurobiology of the disorder and alcohol's molecular targets, limitations include the lack of standardized methods and streamlined processes whereby animal studies can readily inform human studies. Behavioral pharmacology studies provide a less expensive and valuable opportunity to assess the feasibility of a pharmacotherapy prior to initiating larger scale clinical trials by providing insights into the mechanism of the drug, which can then inform recruitment, analyses, and assessments. Summary tables are provided to illustrate the wide range of preclinical, human laboratory, and clinical studies of medications development for alcoholism. Taken together, this review highlights the challenges associated with animal paradigms, human laboratory studies, and clinical trials with the overarching goal of advancing treatment development and highlighting opportunities to bridge the gap between preclinical and clinical research.
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Affiliation(s)
- Megan M. Yardley
- Department of Psychology; University of California, Los Angeles; Los Angeles CA USA
| | - Lara A. Ray
- Department of Psychology; University of California, Los Angeles; Los Angeles CA USA
- Department of Psychiatry and Biobehavioral Sciences; University of California, Los Angeles; Los Angeles CA USA
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30
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Huynh N, Arabian N, Naito A, Louie S, Jakowec MW, Asatryan L, Davies DL. Preclinical development of moxidectin as a novel therapeutic for alcohol use disorder. Neuropharmacology 2016; 113:60-70. [PMID: 27641072 DOI: 10.1016/j.neuropharm.2016.09.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/14/2016] [Accepted: 09/15/2016] [Indexed: 02/08/2023]
Abstract
Current pharmacotherapies for alcohol used disorder (AUD) are few and relatively ineffective illustrating the need for the development of new, effective medications. Using a translational approach, our laboratory reported that ivermectin, an FDA-approved, human and animal anti-parasitic agent, can significantly reduce ethanol intake in male and female mice across different drinking paradigms. Extending this line of investigation, the current paper investigated the utility of moxidectin (MOX), an analogue of ivermectin, to reduce ethanol intake. Notably, MOX is widely held to have lower neurotoxicity potential and improved margin of safety compared to ivermectin. Using a 24-h-two-bottle choice paradigm, MOX significantly reduced ethanol intake in a dose dependent manner in both male and female C57BL/6J mice, respectively (1.25-7.5 mg/kg) and (1.25-10 mg/kg). Further, multi-day administration of MOX (2.5 mg/kg; intraperitoneal injection) for 5 consecutive days significantly reduced ethanol intake in both the 24-h-two-bottle choice and Drinking-in-the-Dark paradigms in female mice. No overt signs of behavioral toxicity were observed. Notably in both male and female mice, MOX significantly reduced ethanol intake starting approximately 4 h post-injection. Using a Xenopus oocyte expression system, we found that MOX significantly potentiated P2X4 receptor (P2X4R) function and antagonized the inhibitory effects of ethanol on ATP-gated currents in P2X4Rs. This latter finding represents the first report of MOX having activity on P2X4Rs. In addition, MOX potentiated GABAA receptors, but to a lesser degree as compared to ivermectin supporting the hypothesis that MOX would be advantageous (compared to ivermectin) with respect to reducing contraindications. Overall, the results illustrate the potential for development of MOX as a novel pharmacotherapy for the treatment of AUD.
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Affiliation(s)
- Nhat Huynh
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Natalie Arabian
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Anna Naito
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Stan Louie
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Michael W Jakowec
- Department of Neurology, Keck School of Medicine, University of Southern California, 1333 San Pablo Street, Los Angeles, CA 90033, USA
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA.
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31
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Xu J, Bernstein AM, Wong A, Lu XH, Khoja S, Yang XW, Davies DL, Micevych P, Sofroniew MV, Khakh BS. P2X4 Receptor Reporter Mice: Sparse Brain Expression and Feeding-Related Presynaptic Facilitation in the Arcuate Nucleus. J Neurosci 2016; 36:8902-20. [PMID: 27559172 PMCID: PMC4995303 DOI: 10.1523/jneurosci.1496-16.2016] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 06/17/2016] [Accepted: 06/20/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED P2X4 receptors are ATP-gated cation channels that are widely expressed in the nervous system. To identify P2X4 receptor-expressing cells, we generated BAC transgenic mice expressing tdTomato under the control of the P2X4 receptor gene (P2rx4). We found sparse populations of tdTomato-positive neurons in most brain areas with patterns that matched P2X4 mRNA distribution. tdTomato expression within microglia was low but was increased by an experimental manipulation that triggered microglial activation. We found surprisingly high tdTomato expression in the hypothalamic arcuate nucleus (Arc) (i.e., within parts of the neural circuitry controlling feeding). Immunohistochemistry and genetic crosses of P2rx4 tdTomato mice with cell-specific GFP reporter lines showed that the tdTomato-expressing cells were mainly AgRP-NPY neurons and tanycytes. There was no electrophysiological evidence for functional expression of P2X4 receptors on AgRP-NPY neuron somata, but instead, we found clear evidence for functional presynaptic P2X4 receptor-mediated responses in terminals of AgRP-NPY neurons onto two of their postsynaptic targets (Arc POMC and paraventricular nucleus neurons), where ATP dramatically facilitated GABA release. The presynaptic responses onto POMC neurons, and the expression of tdTomato in AgRP-NPY neurons and tanycytes, were significantly decreased by food deprivation in male mice in a manner that was partially reversed by the satiety-related peptide leptin. Overall, we provide well-characterized tdTomato reporter mice to study P2X4-expressing cells in the brain, new insights on feeding-related regulation of presynaptic P2X4 receptor responses, and the rationale to explore extracellular ATP signaling in the control of feeding behaviors. SIGNIFICANCE STATEMENT Cells expressing ATP-gated P2X4 receptors have proven problematic to identify and study in brain slice preparations because P2X4 expression is sparse. To address this limitation, we generated and characterized BAC transgenic P2rx4 tdTomato reporter mice. We report the distribution of tdTomato-expressing cells throughout the brain and particularly strong expression in the hypothalamic arcuate nucleus. Together, our studies provide a new, well-characterized tool with which to study P2X4 receptor-expressing cells. The electrophysiological studies enabled by this mouse suggest previously unanticipated roles for ATP and P2X4 receptors in the neural circuitry controlling feeding.
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Affiliation(s)
- Ji Xu
- Departments of Physiology and
| | - Alexander M Bernstein
- Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
| | - Angela Wong
- Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
| | - Xiao-Hong Lu
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California-Los Angeles, Los Angeles, California 90095
| | - Sheraz Khoja
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, California 90089
| | - X William Yang
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California-Los Angeles, Los Angeles, California 90095, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095, and
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, California 90089
| | - Paul Micevych
- Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
| | - Michael V Sofroniew
- Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
| | - Baljit S Khakh
- Departments of Physiology and Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095,
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32
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Khoja S, Shah V, Garcia D, Asatryan L, Jakowec MW, Davies DL. Role of purinergic P2X4 receptors in regulating striatal dopamine homeostasis and dependent behaviors. J Neurochem 2016; 139:134-48. [PMID: 27402173 DOI: 10.1111/jnc.13734] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 06/26/2016] [Accepted: 06/28/2016] [Indexed: 11/27/2022]
Abstract
Purinergic P2X4 receptors (P2X4Rs) belong to the P2X superfamily of ion channels regulated by ATP. We recently demonstrated that P2X4R knockout (KO) mice exhibited deficits in sensorimotor gating, social interaction, and ethanol drinking behavior. Dopamine (DA) dysfunction may underlie these behavioral changes, but there is no direct evidence for P2X4Rs' role in DA neurotransmission. To test this hypothesis, we measured markers of DA function and dependent behaviors in P2X4R KO mice. P2X4R KO mice exhibited altered density of pre-synaptic markers including tyrosine hydroxylase, dopamine transporter; post-synaptic markers including dopamine receptors and phosphorylation of downstream targets including dopamine and cyclic-AMP regulated phosphoprotein of 32 kDa and cyclic-AMP-response element binding protein in different parts of the striatum. Ivermectin, an allosteric modulator of P2X4Rs, significantly affected dopamine and cyclic AMP regulated phosphoprotein of 32 kDa and extracellular regulated kinase1/2 phosphorylation in the striatum. Sensorimotor gating deficits in P2X4R KO mice were rescued by DA antagonists. Using the 6-hydroxydopamine model of DA depletion, P2X4R KO mice exhibited an attenuated levodopa (L-DOPA)-induced motor behavior, whereas ivermectin enhanced this behavior. Collectively, these findings identified an important role for P2X4Rs in maintaining DA homeostasis and illustrate how this association is important for CNS functions including motor control and sensorimotor gating. We propose that P2X4 receptors (P2X4Rs) regulate dopamine (DA) homeostasis and associated behaviors. Pre-synaptic and post-synaptic DA markers were significantly altered in the dorsal and ventral striatum of P2X4R KO mice, implicating altered DA neurotransmission. Sensorimotor gating deficits in P2X4R KO mice were rescued by DA antagonists. Ivermectin (IVM), a positive modulator of P2X4Rs, enhanced levodopa (L-DOPA)-induced motor behavior. These studies highlight potential interactions between P2X4Rs and DA system.
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Affiliation(s)
- Sheraz Khoja
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Vivek Shah
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Damaris Garcia
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Michael W Jakowec
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, California, USA.
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Roche DJO, Yardley MM, Lunny KF, Louie SG, Davies DL, Miotto K, Ray LA. A Pilot Study of the Safety and Initial Efficacy of Ivermectin for the Treatment of Alcohol Use Disorder. Alcohol Clin Exp Res 2016; 40:1312-20. [PMID: 27087145 DOI: 10.1111/acer.13064] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 03/09/2016] [Indexed: 12/27/2022]
Abstract
BACKGROUND Ivermectin (IVM) is an antiparasitic agent that has been shown to reduce alcohol intake in mice, suggesting IVM as a potential treatment for alcohol use disorder (AUD). However, the safety profile of IVM administered in combination with an intoxicating dose of alcohol has not been characterized in humans. METHODS This pilot project sought to provide the first clinical evidence that IVM could be repositioned as an AUD pharmacotherapy by examining (i) the safety of combining IVM (30 mg oral , once a day [QD]) with an intoxicating dose of intravenous alcohol (0.08 g/dl) and (ii) the effects of IVM on alcohol cue-induced craving and subjective response to alcohol. Eleven individuals with AUD participated in a randomized, placebo-controlled, crossover study in which they received the study medication, participated in a cue exposure paradigm followed by intravenous alcohol administration, and remained in an inpatient unit overnight for observation. RESULTS IVM treatment, versus placebo, did not increase the number or severity of adverse effects during alcohol administration or throughout the visit. However, IVM did not reduce cue-induced craving nor did it significantly affect subjective response to alcohol. CONCLUSIONS These results suggest that IVM (30 mg oral, QD) is safe in combination with an intoxicating dose of alcohol, but do not provide evidence that this dose of IVM is effective in reducing alcohol craving or its reinforcing effects. Given the preclinical data suggesting IVM is effective in reducing alcohol consumption in mice, additional studies testing larger samples and alternate dosing regimens are warranted to further characterize the potential efficacy of IVM as an AUD treatment.
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Affiliation(s)
- Daniel J O Roche
- Department of Psychology, University of California, Los Angeles, California
| | - Megan M Yardley
- Department of Psychology, University of California, Los Angeles, California
| | - Katy F Lunny
- Department of Psychology, University of California, Los Angeles, California
| | - Stan G Louie
- Titus Family Department of Clinical Pharmacy, University of Southern California, Los Angeles, California
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, University of Southern California, Los Angeles, California
| | - Karen Miotto
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, California
| | - Lara A Ray
- Department of Psychology, University of California, Los Angeles, California.,Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, California
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Huynh N, Arabian N, Lieu D, Asatryan L, Davies DL. Utilizing an Orally Dissolving Strip for Pharmacological and Toxicological Studies: A Simple and Humane Alternative to Oral Gavage for Animals. J Vis Exp 2016:e53770. [PMID: 27078261 DOI: 10.3791/53770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Prior to testing novel therapeutics in humans, short and long term preclinical (i.e., animal), repetitive pharmacological and toxicological testing is required. In most cases, the preferred route of administration is via oral delivery. At the present time, oral delivery is mostly accomplished using an oral gavage procedure, in part, because it can achieve consistent and precise dosing in the animal model. Although this method is well established it does have complications that can result in a high rate of animal attrition. To this end, the procedure introduced here describes an alternative to the oral gavage method in which the desired drug is incorporated into a tastant, orally dissolving strip (ODS) that can simply be presented to the test animal where it is then rapidly taken up with minimal manipulation of the test subject. Herein, we demonstrate that preclinical, oral drug delivery using the ODS method represents a safe, convenient, and humane alternative to oral gavage.
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Affiliation(s)
- Nhat Huynh
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, University of Southern California School of Pharmacy
| | - Natalie Arabian
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, University of Southern California School of Pharmacy
| | - Dustin Lieu
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, University of Southern California School of Pharmacy
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, University of Southern California School of Pharmacy
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics & Policy, University of Southern California School of Pharmacy;
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Fritz BM, Boehm SL. Rodent models and mechanisms of voluntary binge-like ethanol consumption: Examples, opportunities, and strategies for preclinical research. Prog Neuropsychopharmacol Biol Psychiatry 2016; 65:297-308. [PMID: 26021391 PMCID: PMC4668238 DOI: 10.1016/j.pnpbp.2015.05.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 05/02/2015] [Accepted: 05/21/2015] [Indexed: 02/03/2023]
Abstract
Binge ethanol consumption has widespread negative consequences for global public health. Rodent models offer exceptional power to explore the neurobiology underlying and affected by binge-like drinking as well as target potential prevention, intervention, and treatment strategies. An important characteristic of these models is their ability to consistently produce pharmacologically-relevant blood ethanol concentration. This review examines the current available rodent models of voluntary, pre-dependent binge-like ethanol consumption and their utility in various research strategies. Studies have demonstrated that a diverse array of neurotransmitters regulate binge-like drinking, resembling some findings from other drinking models. Furthermore, repeated binge-like drinking recruits neuroadaptive mechanisms in mesolimbocortical reward circuitry. New opportunities that these models offer in the current context of mechanistic research are also discussed.
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Affiliation(s)
| | - Stephen L Boehm
- Indiana Alcohol Research Center, Department of Psychology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States.
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Franklin KM, Hauser SR, Lasek AW, Bell RL, McBride WJ. Involvement of Purinergic P2X4 Receptors in Alcohol Intake of High-Alcohol-Drinking (HAD) Rats. Alcohol Clin Exp Res 2015; 39:2022-31. [PMID: 26334550 PMCID: PMC4592405 DOI: 10.1111/acer.12836] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 07/01/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND The P2X4 receptor (P2X4R) is thought to be involved in regulating alcohol-consuming behaviors, and ethanol (EtOH) has been reported to inhibit P2X4Rs. Ivermectin is an antiparasitic agent that acts as a positive allosteric modulator of the P2X4R. This study examined the effects of systemically and centrally administered ivermectin on alcohol drinking of replicate lines of high-alcohol-drinking (HAD-1/HAD-2) rats, and the effects of lentiviral-delivered short-hairpin RNAs (shRNAs) targeting P2rx4 on EtOH intake of female HAD-2 rats. METHODS For the first experiment, adult male HAD-1 and HAD-2 rats were given 24-hour free-choice access to 15% EtOH versus water. Dose-response effects of ivermectin (1.5 to 7.5 mg/kg, intraperitoneally [i.p.]) on EtOH intake were determined; the effects of ivermectin were then examined for 2% w/v sucrose intake over 5 consecutive days. In the second experiment, female HAD-2 rats were trained to consume 15% EtOH under 2-hour limited access conditions, and dose-response effects of intracerebroventricular (ICV) administration of ivermectin (0.5 to 2.0 μg) were determined over 5 consecutive days. The third experiment determined the effects of microinfusion of a lentivirus expressing P2rx4 shRNAs into the posterior ventral tegmental area (VTA) on 24-hour EtOH free-choice drinking of female HAD-2 rats. RESULTS The highest i.p. dose of ivermectin reduced alcohol drinking (30 to 45%) in both rat lines, but did not alter sucrose intake. HAD-2 rats appeared to be more sensitive than HAD-1 rats to the effects of ivermectin. ICV administration of ivermectin reduced 2-hour limited access intake (~35%) of female HAD-2 rats; knockdown of P2rx4 expression in the posterior VTA reduced 24-hour free-choice EtOH intake (~20%). CONCLUSIONS Overall, the results of this study support a role for P2X4Rs within the mesolimbic system in mediating alcohol-drinking behavior.
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Affiliation(s)
- Kelle M. Franklin
- Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Sheketha R. Hauser
- Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Amy W. Lasek
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Richard L. Bell
- Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - William J. McBride
- Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Biochemistry, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
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Korpi ER, den Hollander B, Farooq U, Vashchinkina E, Rajkumar R, Nutt DJ, Hyytiä P, Dawe GS. Mechanisms of Action and Persistent Neuroplasticity by Drugs of Abuse. Pharmacol Rev 2015; 67:872-1004. [DOI: 10.1124/pr.115.010967] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Yardley MM, Huynh N, Rodgers KE, Alkana RL, Davies DL. Oral delivery of ivermectin using a fast dissolving oral film: Implications for repurposing ivermectin as a pharmacotherapy for alcohol use disorder. Alcohol 2015; 49:553-9. [PMID: 26095588 DOI: 10.1016/j.alcohol.2015.03.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/23/2015] [Accepted: 03/26/2015] [Indexed: 11/29/2022]
Abstract
Individuals suffering from an alcohol-use disorder (AUD) constitute a major health concern. Preclinical studies in our laboratory show that acute and chronic intraperitoneal (i.p.) administration of ivermectin (IVM) reduces alcohol intake and preference in mice. To enable clinical investigation to use IVM for the treatment of an AUD, development of an oral formulation that can be used in animals as well as long-term preclinical toxicology studies are required. The present work explores the use of a promising alternative dosage form of IVM, fast-dissolving oral films (Cure Pharmaceutical®), to test the efficacy and safety of oral IVM in conjunction with alcohol exposure. We tested the effect of IVM (0.21 mg) using a fast-dissolving oral film delivery method on reducing 10% v/v alcohol (10E) intake in female C57BL/6 mice using a 24-h access two-bottle choice paradigm for 6 weeks (5 days per week). Differences in ethanol intake, preference for ethanol, water intake, fluid intake, food intake, changes in mouse and organ weights, as well as histological changes to kidney, liver, and brain were analyzed. The IVM group drank significantly less ethanol over the 30-day period compared to the placebo (blank strip) and the no-treatment groups. Organ weights did not differ between the groups. Histological evaluation showed no differences in the brain and kidney between groups. In the liver, there was a slight increase in the incidence of microvesicular fatty and degenerative changes of the animals receiving the thin strips. No overt hepatocellular necrosis or perivascular inflammation was noted. Overall, these data support the use of this novel method of oral drug delivery for longer-term studies and should facilitate FDA required preclinical testing that is necessary to repurpose IVM for treatment of an AUD.
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Affiliation(s)
- Megan M Yardley
- Department of Psychology, University of California, Los Angeles, CA 90095, USA
| | - Nhat Huynh
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, 1985 Zonal Ave., Los Angeles, CA 90033, USA
| | - Kathleen E Rodgers
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, 1985 Zonal Ave., Los Angeles, CA 90033, USA
| | - Ronald L Alkana
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Ave., Los Angeles, CA 90033, USA
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, 1985 Zonal Ave., Los Angeles, CA 90033, USA.
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Multiday administration of ivermectin is effective in reducing alcohol intake in mice at doses shown to be safe in humans. Neuroreport 2015; 25:1018-23. [PMID: 25004078 DOI: 10.1097/wnr.0000000000000211] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ivermectin (IVM), an FDA approved anthelmintic agent, can significantly reduce ethanol intake in mice following acute administration. The current study evaluates the sustainability and safety of multiday IVM administration in reducing 10% v/v ethyl alcohol (10E) intake in mice at a dose shown to be safe in humans. We tested the effect of 10-day administration of IVM (3.0 mg/kg/day; intraperitoneally) on reducing 10E intake in C57BL/6J mice using a 24-h, two-bottle choice paradigm. On the 10th day of IVM administration, mice were sacrificed at 0, 0.5, 2, 8, 32, 48, and 72 h after injection. Brain tissue and plasma samples were collected and analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Analysis of variance (ANOVA) was used to assess the effect of 10-day IVM administration on 10E intake, 10E preference, water intake, and total fluid intake with Dunnett's multiple comparison post-hoc test. Individual Student's t-tests were also used to further quantify changes in these dependent variables. IVM significantly decreased 10E intake over a 9-day period (P<0.01). Pre-IVM 10E intake was 9.1±3.2 g/kg/24 h. Following the 9th day of IVM injections, intake dropped by almost 30% (P<0.05). IVM had no effect on total water intake or mouse weight throughout the study; however, there was a significant decrease in both preference for 10E (P<0.01) and total fluid intake (P<0.05). Multiday administration of IVM significantly reduces 10E intake and preference in animals without causing any apparent adverse effects at a dose shown to be safe in humans.
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Hu L, Lan W, Guo H, Chai GD, Huang K, Zhang L, Huang Y, Chen XF, Zhang L, Song NN, Chen L, Lang B, Wang Y, Wang QX, Zhang JB, McCaig C, Xu L, Ding YQ. A mouse line for inducible and reversible silencing of specific neurons. Mol Brain 2014; 7:68. [PMID: 25231486 PMCID: PMC4177062 DOI: 10.1186/s13041-014-0068-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 08/31/2014] [Indexed: 11/13/2022] Open
Abstract
Background Genetic methods for inducibly and reversibly inhibiting neuronal activity of specific neurons are critical for exploring the functions of neuronal circuits. The engineered human glycine receptor, called ivermectin (IVM)-gated silencing receptor (IVMR), has been shown to possess this ability in vitro. Results Here we generated a mouse line, in which the IVMR coding sequence was inserted into the ROSA26 locus downstream of a loxP-flanked STOP cassette. Specific Cre-mediated IVMR expression was revealed by mis-expression of Cre in the striatum and by crossing with several Cre lines. Behavioral alteration was observed in Rosa26-IVMR mice with unilateral striatal Cre expression after systemic administration of IVM, and it could be re-initiated when IVM was applied again. A dramatic reduction in neuron firing was recorded in IVM-treated free moving Rosa26-IVMR;Emx1-Cre mice, and neuronal excitability was reduced within minutes as shown by recording in brain slice. Conclusion This Rosa26-IVMR mouse line provides a powerful tool for exploring selective circuit functions in freely behaving mice. Electronic supplementary material The online version of this article (doi:10.1186/s13041-014-0068-8) contains supplementary material, which is available to authorized users.
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In vivo protection against strychnine toxicity in mice by the glycine receptor agonist ivermectin. BIOMED RESEARCH INTERNATIONAL 2014; 2014:640790. [PMID: 25317421 PMCID: PMC4181905 DOI: 10.1155/2014/640790] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/24/2014] [Indexed: 11/17/2022]
Abstract
The inhibitory glycine receptor, a ligand-gated ion channel that mediates fast synaptic inhibition in mammalian spinal cord and brainstem, is potently and selectively inhibited by the alkaloid strychnine. The anthelminthic and anticonvulsant ivermectin is a strychnine-independent agonist of spinal glycine receptors. Here we show that ivermectin is an effective antidote of strychnine toxicity in vivo and determine time course and extent of ivermectin protection. Mice received doses of 1 mg/kg and 5 mg/kg ivermectin orally or intraperitoneally, followed by an intraperitoneal strychnine challenge (2 mg/kg). Ivermectin, through both routes of application, protected mice against strychnine toxicity. Maximum protection was observed 14 hours after ivermectin administration. Combining intraperitoneal and oral dosage of ivermectin further improved protection, resulting in survival rates of up to 80% of animals and a significant delay of strychnine effects in up to 100% of tested animals. Strychnine action developed within minutes, much faster than ivermectin, which acted on a time scale of hours. The data agree with a two-compartment distribution of ivermectin, with fat deposits acting as storage compartment. The data demonstrate that toxic effects of strychnine in mice can be prevented if a basal level of glycinergic signalling is maintained through receptor activation by ivermectin.
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Franklin KM, Asatryan L, Jakowec MW, Trudell JR, Bell RL, Davies DL. P2X4 receptors (P2X4Rs) represent a novel target for the development of drugs to prevent and/or treat alcohol use disorders. Front Neurosci 2014; 8:176. [PMID: 25009459 PMCID: PMC4068020 DOI: 10.3389/fnins.2014.00176] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Accepted: 06/05/2014] [Indexed: 12/19/2022] Open
Abstract
Alcohol use disorders (AUDs) have a staggering socioeconomic impact. Few therapeutic options are available, and they are largely inadequate. These shortcomings highlight the urgent need to develop effective medications to prevent and/or treat AUDs. A critical barrier is the lack of information regarding the molecular target(s) by which ethanol (EtOH) exerts its pharmacological activity. This review highlights findings implicating P2X4 receptors (P2X4Rs) as a target for the development of therapeutics to treat AUDs and discusses the use of ivermectin (IVM) as a potential clinical tool for treatment of AUDs. P2XRs are a family of ligand-gated ion channels (LGICs) activated by extracellular ATP. Of the P2XR subtypes, P2X4Rs are expressed the most abundantly in the CNS. Converging evidence suggests that P2X4Rs are involved in the development and progression of AUDs. First, in vitro studies report that pharmacologically relevant EtOH concentrations can negatively modulate ATP-activated currents. Second, P2X4Rs in the mesocorticolimbic dopamine system are thought to play a role in synaptic plasticity and are located ideally to modulate brain reward systems. Third, alcohol-preferring (P) rats have lower functional expression of the p2rx4 gene than alcohol-non-preferring (NP) rats suggesting an inverse relationship between alcohol intake and P2X4R expression. Similarly, whole brain p2rx4 expression has been shown to relate inversely to innate 24 h alcohol preference across 28 strains of rats. Fourth, mice lacking the p2rx4 gene drink more EtOH than wildtype controls. Fifth, IVM, a positive modulator of P2X4Rs, antagonizes EtOH-mediated inhibition of P2X4Rs in vitro and reduces EtOH intake and preference in vivo. These findings suggest that P2X4Rs contribute to EtOH intake. The present review summarizes recent findings focusing on the P2X4R as a molecular target of EtOH action, its role in EtOH drinking behavior and modulation of its activity by IVM as a potential therapy for AUDs.
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Affiliation(s)
- Kelle M Franklin
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine Indianapolis, IN, USA
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California Los Angeles, CA, USA
| | - Michael W Jakowec
- Department of Neurology, University of Southern California Los Angeles, CA, USA
| | - James R Trudell
- Beckman Program for Molecular and Genetic Medicine, Department of Anesthesia, Stanford University Palo Alto, CA, USA
| | - Richard L Bell
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine Indianapolis, IN, USA
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California Los Angeles, CA, USA
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Xu J, Chai H, Ehinger K, Egan TM, Srinivasan R, Frick M, Khakh BS. Imaging P2X4 receptor subcellular distribution, trafficking, and regulation using P2X4-pHluorin. ACTA ACUST UNITED AC 2014; 144:81-104. [PMID: 24935743 PMCID: PMC4076521 DOI: 10.1085/jgp.201411169] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A P2X4 receptor labeled with the pH-sensitive GFP superecliptic pHluorin represents a useful probe to investigate P2X4 receptor distribution, trafficking, and up-regulation. P2X4 receptors are adenosine triphosphate (ATP)-gated cation channels present on the plasma membrane (PM) and also within intracellular compartments such as vesicles, vacuoles, lamellar bodies (LBs), and lysosomes. P2X4 receptors in microglia are up-regulated in epilepsy and in neuropathic pain; that is to say, their total and/or PM expression levels increase. However, the mechanisms underlying up-regulation of microglial P2X4 receptors remain unclear, in part because it has not been possible to image P2X4 receptor distribution within, or trafficking between, cellular compartments. Here, we report the generation of pH-sensitive fluorescently tagged P2X4 receptors that permit evaluations of cell surface and total receptor pools. Capitalizing on information gained from zebrafish P2X4.1 crystal structures, we designed a series of mouse P2X4 constructs in which a pH-sensitive green fluorescent protein, superecliptic pHluorin (pHluorin), was inserted into nonconserved regions located within flexible loops of the P2X4 receptor extracellular domain. One of these constructs, in which pHluorin was inserted after lysine 122 (P2X4-pHluorin123), functioned like wild-type P2X4 in terms of its peak ATP-evoked responses, macroscopic kinetics, calcium flux, current–voltage relationship, and sensitivity to ATP. P2X4-pHluorin123 also showed pH-dependent fluorescence changes, and was robustly expressed on the membrane and within intracellular compartments. P2X4-pHluorin123 identified cell surface and intracellular fractions of receptors in HEK-293 cells, hippocampal neurons, C8-B4 microglia, and alveolar type II (ATII) cells. Furthermore, it showed that the subcellular fractions of P2X4-pHluorin123 receptors were cell and compartment specific, for example, being larger in hippocampal neuron somata than in C8-B4 cell somata, and larger in C8-B4 microglial processes than in their somata. In ATII cells, P2X4-pHluorin123 showed that P2X4 receptors were secreted onto the PM when LBs undergo exocytosis. Finally, the use of P2X4-pHluorin123 showed that the modulator ivermectin did not increase the PM fraction of P2X4 receptors and acted allosterically to potentiate P2X4 receptor responses. Collectively, our data suggest that P2X4-pHluorin123 represents a useful optical probe to quantitatively explore P2X4 receptor distribution, trafficking, and up-regulation.
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Affiliation(s)
- Ji Xu
- Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Hua Chai
- Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | | | - Terrance M Egan
- Department of Pharmacological and Physiological Science and The Center for Excellence in Neuroscience, Saint Louis University School of Medicine, St. Louis, MO 63130 Department of Pharmacological and Physiological Science and The Center for Excellence in Neuroscience, Saint Louis University School of Medicine, St. Louis, MO 63130
| | - Rahul Srinivasan
- Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Manfred Frick
- Institute of General Physiology, University of Ulm, 89081 Ulm, Germany
| | - Baljit S Khakh
- Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095Department of Physiology and Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
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Avermectins differentially affect ethanol intake and receptor function: implications for developing new therapeutics for alcohol use disorders. Int J Neuropsychopharmacol 2014; 17:907-16. [PMID: 24451653 PMCID: PMC4209915 DOI: 10.1017/s1461145713001703] [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] [Indexed: 11/06/2022] Open
Abstract
Our laboratory is investigating ivermectin (IVM) and other members of the avermectin family as new pharmaco-therapeutics to prevent and/or treat alcohol use disorders (AUDs). Earlier work found that IVM significantly reduced ethanol intake in mice and that this effect likely reflects IVM's ability to modulate ligand-gated ion channels. We hypothesized that structural modifications that enhance IVM's effects on key receptors and/or increase its brain concentration should improve its anti-alcohol efficacy. We tested this hypothesis by comparing the abilities of IVM and two other avermectins, abamectin (ABM) and selamectin (SEL), to reduce ethanol intake in mice, to alter modulation of GABAARs and P2X4Rs expressed in Xenopus oocytes and to increase their ability to penetrate the brain. IVM and ABM significantly reduced ethanol intake and antagonized the inhibitory effects of ethanol on P2X4R function. In contrast, SEL did not affect either measure, despite achieving higher brain concentrations than IVM and ABM. All three potentiated GABAAR function. These findings suggest that chemical structure and effects on receptor function play key roles in the ability of avermectins to reduce ethanol intake and that these factors are more important than brain penetration alone. The direct relationship between the effect of these avermectins on P2X4R function and ethanol intake suggest that the ability to antagonize ethanol-mediated inhibition of P2X4R function may be a good predictor of the potential of an avermectin to reduce ethanol intake and support the use of avermectins as a platform for developing novel drugs to prevent and/or treat AUDs.
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Wyatt LR, Finn DA, Khoja S, Yardley MM, Asatryan L, Alkana RL, Davies DL. Contribution of P2X4 receptors to ethanol intake in male C57BL/6 mice. Neurochem Res 2014; 39:1127-39. [PMID: 24671605 DOI: 10.1007/s11064-014-1271-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 02/15/2014] [Accepted: 02/26/2014] [Indexed: 11/26/2022]
Abstract
P2X receptors (P2XRs) are a family of cation-permeable ligand-gated ion channels activated by synaptically released extracellular adenosine 5'-triphosphate. The P2X4 subtype is abundantly expressed in the central nervous system and is sensitive to low intoxicating ethanol concentrations. Genetic meta-analyses identified the p2rx4 gene as a candidate gene for innate alcohol intake and/or preference. The current study used mice lacking the p2rx4 gene (knockout, KO) and wildtype (WT) C57BL/6 controls to test the hypothesis that P2X4Rs contribute to ethanol intake. The early acquisition and early maintenance phases of ethanol intake were measured with three different drinking procedures. Further, we tested the effects of ivermectin (IVM), a drug previously shown to reduce ethanol's effects on P2X4Rs and to reduce ethanol intake and preference, for its ability to differentially alter stable ethanol intake in KO and WT mice. Depending on the procedure and the concentration of the ethanol solution, ethanol intake was transiently increased in P2X4R KO versus WT mice during the acquisition of 24-h and limited access ethanol intake. IVM significantly reduced ethanol intake in P2X4R KO and WT mice, but the degree of reduction was 50 % less in the P2X4R KO mice. Western blot analysis identified significant changes in γ-aminobutyric acidA receptor α1 subunit expression in brain regions associated with the regulation of ethanol behaviors in P2X4R KO mice. These findings add to evidence that P2X4Rs contribute to ethanol intake and indicate that there is a complex interaction between P2X4Rs, ethanol, and other neurotransmitter receptor systems.
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Affiliation(s)
- Letisha R Wyatt
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90033, USA
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Howard RJ, Trudell JR, Harris RA. Seeking structural specificity: direct modulation of pentameric ligand-gated ion channels by alcohols and general anesthetics. Pharmacol Rev 2014; 66:396-412. [PMID: 24515646 PMCID: PMC3973611 DOI: 10.1124/pr.113.007468] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Alcohols and other anesthetic agents dramatically alter neurologic function in a wide range of organisms, yet their molecular sites of action remain poorly characterized. Pentameric ligand-gated ion channels, long implicated in important direct effects of alcohol and anesthetic binding, have recently been illuminated in renewed detail thanks to the determination of atomic-resolution structures of several family members from lower organisms. These structures provide valuable models for understanding and developing anesthetic agents and for allosteric modulation in general. This review surveys progress in this field from function to structure and back again, outlining early evidence for relevant modulation of pentameric ligand-gated ion channels and the development of early structural models for ion channel function and modulation. We highlight insights and challenges provided by recent crystal structures and resulting simulations, as well as opportunities for translation of these newly detailed models back to behavior and therapy.
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Affiliation(s)
- Rebecca J Howard
- Department of Chemistry, Skidmore College, Saratoga Springs, NY 12866.
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Anton RF, Schacht JP, Book SW. Pharmacologic treatment of alcoholism. HANDBOOK OF CLINICAL NEUROLOGY 2014; 125:527-42. [PMID: 25307594 DOI: 10.1016/b978-0-444-62619-6.00030-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Progress in understanding the neuroscience of addiction has significantly advanced the development of more efficacious medications for the treatment of alcohol use disorders (AUD). While several medications have been approved by regulatory bodies around the world for the treatment of AUD, they are not universally efficacious. Recent research has yielded improved understanding of the genetics and brain circuits that underlie alcohol reward and its habitual use. This research has contributed to pharmacogenetic studies of medication response, and will ultimately lead to a more "personalized medicine" approach to AUD pharmacotherapy. This chapter summarizes work on clinically available medications (both approved by regulatory bodies and investigational) for the treatment of alcohol dependence, as well as the psychiatric disorders that are commonly comorbid with AUD. Studies that have evaluated genetic influences on medication response and those that have employed neuroimaging to probe mechanisms of medication action or response are highlighted. Finally, new targets discovered in animal models for possible pharmacologic intervention in humans are overviewed and future directions in medications development provided.
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Affiliation(s)
- Raymond F Anton
- Center for Drug and Alcohol Programs, Alcohol Research Center, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA.
| | - Joseph P Schacht
- Center for Drug and Alcohol Programs, Alcohol Research Center, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Sarah W Book
- Center for Drug and Alcohol Programs, Alcohol Research Center, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
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Tryptophan 46 is a site for ethanol and ivermectin action in P2X4 receptors. Purinergic Signal 2013; 9:621-32. [PMID: 23817978 DOI: 10.1007/s11302-013-9373-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 06/11/2013] [Indexed: 01/26/2023] Open
Abstract
ATP-gated purinergic P2X4 receptors (P2X4Rs) are the most alcohol-sensitive P2XR subtype. We recently reported that ivermectin (IVM), an antiparasitic used in animals and humans, antagonized ethanol inhibition of P2X4Rs. Furthermore, IVM reduced ethanol intake in mice. The first molecular model of the rat P2X4R, built onto the X-ray crystal structure of zebrafish P2X4R, revealed an action pocket for both ethanol and IVM formed by Asp331, Met336 in TM2 and Trp46, and Trp50 in TM1 segments. The role of Asp331 and Met336 was experimentally confirmed. The present study tested the hypothesis that Trp46 plays a role in ethanol and IVM modulation of P2X4Rs. Trp46 was mutated to residues with different physicochemical properties and the resultant mutants tested for ethanol and IVM responses using Xenopus oocyte expression system and two-electrode voltage clamp. Nonaromatic substitutions at position 46 reduced ethanol inhibition at higher concentrations and switched IVM potentiation to inhibition. Simultaneous substitution of alanine at positions Trp46 and Met336 also resulted in similar changes in ethanol and IVM responses. Furthermore, a new molecular model based on the open pore conformation of zebrafish P2X4R suggested a role for Tyr42 that was further supported experimentally. Our previous and current findings, combined with our preliminary evidence of increased ethanol consumption in P2X4R knockout mice, suggest that the ethanol and IVM action pocket in P2X4Rs formed by positions 42, 46, 331, and 336 presents a potential target for medication development for alcohol use disorders.
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Pharmacological insights into the role of P2X4 receptors in behavioural regulation: lessons from ivermectin. Int J Neuropsychopharmacol 2013; 16:1059-70. [PMID: 23174033 PMCID: PMC3593990 DOI: 10.1017/s1461145712000909] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Purinergic ionotropic P2X receptors are a family of cation-permeable channels that bind extracellular adenosine 5'-triphosphate. In particular, convergent lines of evidence have recently highlighted P2X(4) receptors as a potentially critical target in the regulation of multiple nervous and behavioural functions, including pain, neuroendocrine regulation and hippocampal plasticity. Nevertheless, the role of the P2X(4) receptor in behavioural organization remains poorly investigated. To study the effects of P2X(4) activation, we tested the acute effects of its potent positive allosteric modulator ivermectin (IVM, 2.5-10 mg/kg i.p.) on a broad set of paradigms capturing complementary aspects of perceptual, emotional and cognitive regulation in mice. In a novel open field, IVM did not induce significant changes in locomotor activity, but increased the time spent in the peripheral zone. In contrast, IVM produced anxiolytic-like effects in the elevated plus maze and marble burying tasks, as well as depression-like behaviours in the tail-suspension and forced swim tests. The agent induced no significant behavioural changes in the conditioned place preference test and in the novel object recognition task. Finally, the drug induced a dose-dependent decrease in sensorimotor gating, as assessed by pre-pulse inhibition (PPI) of the acoustic startle reflex. In P2X(4) knockout mice, the effects of IVM in the open field and elevated plus maze were similar to those observed in wild type mice; conversely, the drug significantly increased startle amplitude and failed to reduce PPI. Taken together, these results suggest that P2X(4) receptors may play a role in the regulation of sensorimotor gating.
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Davies DL, Bortolato M, Finn DA, Ramaker MJ, Barak S, Ron D, Liang J, Olsen RW. Recent advances in the discovery and preclinical testing of novel compounds for the prevention and/or treatment of alcohol use disorders. Alcohol Clin Exp Res 2012; 37:8-15. [PMID: 22671690 DOI: 10.1111/j.1530-0277.2012.01846.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 03/26/2012] [Indexed: 11/27/2022]
Abstract
Alcohol abuse and dependence have a staggering socioeconomic impact, yet current therapeutic strategies are largely inadequate to treat these disorders. Thus, the development of new strategies that can effectively prevent alcohol use disorders (AUDs) is of paramount importance. Currently approved medications attempt to deter alcohol intake by blocking ethanol metabolism or by targeting the neurochemical systems downstream of the cascades leading to craving and dependence. Unfortunately, these medications have provided only limited success as indicated by the continued high rates of alcohol abuse and alcoholism. The lack of currently available effective treatment strategies is highlighted by the urgent call by the NIAAA to find new and paradigm-changing therapeutics to either prevent or treat alcohol-related problems. This mini-review highlights recent findings from 4 laboratories with a focus on compounds that have the potential to be novel therapeutic agents that can be developed for the prevention and/or treatment of AUDs.
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Affiliation(s)
- Daryl L Davies
- School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA.
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