Alcohol use disorders (AUDs) have a staggering socio-economic impact, yet current therapeutic strategies are largely inadequate, due, in part, to a lack of information regarding the molecular target(s) on which ethanol acts. The current proposal tests the hypothesis that P2X4 receptors (P2X4Rs) represent a novel target for the development of drugs to prevent and/or treat AUDs. This target has not yet been explored. We have assembled a multidisciplinary team of investigators that together will use state of the art genetic, molecular, chemical and behavioral techniques to systematically test for targets in the mesolimbic dopamine (DA) system that will be amenable for drug development. The proposed studies will translate laboratory findings into opportunities to discover and develop novel therapeutics for the prevention and treatment of AUDs.
Aim 1 studies will test the hypothesis that P2X4Rs within the brain dopamine reward systems regulate ethanol intake. Study 1, we will evaluate the effects of constitutive knockout of the p2rx4 gene (P2X4KO) on alcohol intake (24 hr access and drinking in the dark [DID] tests). Study 2, using targeted delivery of lentiviral-mediated short hairpin RNA (shRNA), we will knockdown P2X4R expression in the nucleus accumbens (NAc) and/or ventral tegmental area (VTA) to gain insights into specific contributions of the mesolimbic DA system regarding short- term effects of P2X4R reduction/blockade. This work will also help clarify the role of P2X4Rs in causing or modulating the effects of ethanol without the potential developmental alterations that may accompany constitutive KOs. We will use a new, selective P2X4R antagonist, 5-BDBD and develop new related probes, as a third method to determine P2X4Rs role in intoxication. Successful pharmacological manipulation of P2X4Rs would provide new insights into the importance of P2X4Rs as a viable target for future therapies for AUDs. Study 3, using molecular biological, brain slice electrophysiology and fast scan cyclic voltammetry we will begin to investigate the role of P2X4Rs in the NAc and VTA of the mesolimbic DA system. This work will provide mechanistic insights regarding P2X4Rs in the mesolimbic DA system and how they interact to modulate ethanol intake and behavior in mice (Studies 1 and 2).
Aim 2 studies will use ivermectin (IVM), a positive modulator of P2X4Rs, in combination with P2X4KO mice, to test the hypothesis that stimulation of P2X4Rs will decrease ethanol intake. In addition, we will design, synthesize and test new chemical entities with positive, negative or null activity on P2X4R that can serve as pharmacologic probes to interrogate the P2X4R system. Taken together, the work will further our long term goal of identifying neurochemical mechanisms and key brain regions that control alcohol intake. Moreover, this work will identify new targets and will begin to develo new compounds for the translational development of therapeutic agents to prevent and or treat AUDs.

Public Health Relevance

Alcohol use disorders (AUDs) have a staggering socio-economic impact, yet current therapeutic strategies are largely inadequate to treat these disorders. We contend that P2X4Rs represent a novel target for the development of drugs to prevent and/or treat AUDs. Findings from the current application will provide strong support for this hypothesis from several directions including development of lead compounds for drug development. DESCRIPTION (provided by applicant): Alcohol use disorders (AUDs) have a staggering socio-economic impact, yet current therapeutic strategies are largely inadequate, due, in part, to a lack of information regarding the molecular target(s) on which ethanol acts. The current proposal tests the hypothesis that P2X4 receptors (P2X4Rs) represent a novel target for the development of drugs to prevent and/or treat AUDs. This target has not yet been explored. We have assembled a multidisciplinary team of investigators that together will use state of the art genetic, molecular, chemical and behavioral techniques to systematically test for targets in the mesolimbic dopamine (DA) system that will be amenable for drug development. The proposed studies will translate laboratory findings into opportunities to discover and develop novel therapeutics for the prevention and treatment of AUDs. Aim 1 studies will test the hypothesis that P2X4Rs within the brain dopamine reward systems regulate ethanol intake. Study 1, we will evaluate the effects of constitutive knockout of the p2rx4 gene (P2X4KO) on alcohol intake (24 hr access and drinking in the dark [DID] tests). Study 2, using targeted delivery of lentiviral-mediated short hairpin RNA (shRNA), we will knockdown P2X4R expression in the nucleus accumbens (NAc) and/or ventral tegmental area (VTA) to gain insights into specific contributions of the mesolimbic DA system regarding short- term effects of P2X4R reduction/blockade. This work will also help clarify the role of P2X4Rs in causing or modulating the effects of ethanol without the potential developmental alterations that may accompany constitutive KOs. We will use a new, selective P2X4R antagonist, 5-BDBD and develop new related probes, as a third method to determine P2X4Rs role in intoxication. Successful pharmacological manipulation of P2X4Rs would provide new insights into the importance of P2X4Rs as a viable target for future therapies for AUDs. Study 3, using molecular biological, brain slice electrophysiology and fast scan cyclic voltammetry we will begin to investigate the role of P2X4Rs in the NAc and VTA of the mesolimbic DA system. This work will provide mechanistic insights regarding P2X4Rs in the mesolimbic DA system and how they interact to modulate ethanol intake and behavior in mice (Studies 1 and 2). Aim 2 studies will use ivermectin (IVM), a positive modulator of P2X4Rs, in combination with P2X4KO mice, to test the hypothesis that stimulation of P2X4Rs will decrease ethanol intake. In addition, we will design, synthesize and test new chemical entities with positive, negative or null activity on P2X4R that can serve as pharmacologic probes to interrogate the P2X4R system. Taken together, the work will further our long term goal of identifying neurochemical mechanisms and key brain regions that control alcohol intake. Moreover, this work will identify new targets and will begin to develo new compounds for the translational development of therapeutic agents to prevent and or treat AUDs.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
5R01AA022448-03
Application #
8871624
Study Section
Neurotoxicology and Alcohol Study Section (NAL)
Program Officer
Cui, Changhai
Project Start
2013-09-01
Project End
2016-09-04
Budget Start
2015-07-01
Budget End
2016-09-04
Support Year
3
Fiscal Year
2015
Total Cost
Indirect Cost
Name
University of Southern California
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
072933393
City
Los Angeles
State
CA
Country
United States
Zip Code
90032
Khoja, Sheraz; Huynh, Nhat; Warnecke, Alicia M P et al. (2018) Preclinical evaluation of avermectins as novel therapeutic agents for alcohol use disorders. Psychopharmacology (Berl) 235:1697-1709
Khoja, Sheraz; Huynh, Nhat; Asatryan, Liana et al. (2018) Reduced expression of purinergic P2X4 receptors increases voluntary ethanol intake in C57BL/6J mice. Alcohol 68:63-70
Csóka, Balázs; Németh, Zoltán H; Szabó, Ildikó et al. (2018) Macrophage P2X4 receptors augment bacterial killing and protect against sepsis. JCI Insight 3:
Huynh, Nhat; Arabian, Natalie; Naito, Anna et al. (2017) Preclinical development of moxidectin as a novel therapeutic for alcohol use disorder. Neuropharmacology 113:60-70
Huynh, Nhat; Arabian, Natalie; Lieu, Dustin et al. (2016) Utilizing an Orally Dissolving Strip for Pharmacological and Toxicological Studies: A Simple and Humane Alternative to Oral Gavage for Animals. J Vis Exp :e53770
Xu, Ji; Bernstein, Alexander M; Wong, Angela et al. (2016) P2X4 Receptor Reporter Mice: Sparse Brain Expression and Feeding-Related Presynaptic Facilitation in the Arcuate Nucleus. J Neurosci 36:8902-20
Khoja, Sheraz; Shah, Vivek; Garcia, Damaris et al. (2016) Role of purinergic P2X4 receptors in regulating striatal dopamine homeostasis and dependent behaviors. J Neurochem 139:134-48
Guizzetti, Marina; Davies, Daryl L; Egli, Mark et al. (2016) Sex and the Lab: An Alcohol-Focused Commentary on the NIH Initiative to Balance Sex in Cell and Animal Studies. Alcohol Clin Exp Res 40:1182-91
Helms, Christa M; Bell, Richard L; Bennett, Allyson J et al. (2015) The importance of animals in advancing research on alcohol use disorders. Alcohol Clin Exp Res 39:575-8
Asatryan, Liana; Khoja, Sheraz; Rodgers, Kathleen E et al. (2015) Chronic ethanol exposure combined with high fat diet up-regulates P2X7 receptors that parallels neuroinflammation and neuronal loss in C57BL/6J mice. J Neuroimmunol 285:169-79

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