Alcohol (EtOH) abuse and dependence continue to be significant public health problems. Thus, a better understanding of their neurobiology will facilitate the development of interventions targeting prevention and/or treatment of these major health issues. Emerging evidence indicates that many aspects of EtOH and drug dependence involve changes in glutamate transmission. Because glutamate transporter 1 (GLT1) is responsible for the uptake of the majority of extracellular glutamate, we tested the hypothesis that increased GLT1 function would attenuate EtOH consumption in alcohol-preferring rats (P rats). After P rats had been chronically exposed to a free choice of EtOH (15 and 30%) for five weeks, they were administered ceftriaxone (i.p.), a beta-lactam antibiotic known to elevate GLT1 expression, for five consecutive days. We found that ceftriaxone-treated P rats showed a reduction in EtOH intake for the duration of treatment as compared to rats that received a saline vehicle. The long-term effects of ceftriaxone, however, are unknown. Here, we will test the long-term effects of ceftriaxone and other drugs (GPI-1046 and MS-153) known to activate GLT1 in the attenuation of EtOH intake at two different time points of chronic EtOH exposure in P rats. We will also investigate the effects of GLT1 activation in EtOH-drinking behavior in Wistar rats as comparison control groups. Our working hypothesis in aim 1 is that an increase in GLT1 function, via up- regulation or activation, attenuates EtOH consumption in both P and Wistar rats. The EtOH deprivation effect, which we will employ, has been used to assess relapse-like behavior in P rats.
In aim 2, our working hypothesis is that an increase in GLT1 function during withdrawal periods will reduce relapse-like behavior when animals are re-exposed to EtOH. The lowest tested dose of ceftriaxone (25 mg/kg), which did not show an increase in GLT1 expression, was also effective in reducing EtOH intake. These findings suggest that ceftriaxone may have other pharmacological effects on GLT1 or may act by another mechanism (a functional increase may involve a change in one of several mechanisms). Thus, we propose in aim 3 to determine the signaling pathways involving ceftriaxone or GPI-1046 in up-regulation of GLT1 expression. Moreover, we aim to determine the molecular mechanisms of action of ceftriaxone, GPI-1046 and MS-153, which may involve activation of GLT1 function through phosphorylation of key proteins. The findings generated from this proposal will provide ample information about the role of GLT1 in the regulation of EtOH consumption and will pave the path toward finding a potential therapeutic target for alcohol addiction.

Public Health Relevance

The goal of this proposal is to investigate the role of glutamate transporter, a neurotransmitter transporter, in alcohol dependence. This chemical transporter plays an important role in alcohol-drinking behavior. From this study, we aim to provide ample information about the role of this transporter in the reduction of alcohol consumption and hope to pave the path toward potential therapeutic targets for alcohol dependence.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
5R01AA019458-04
Application #
8660252
Study Section
Neurotoxicology and Alcohol Study Section (NAL)
Program Officer
Cui, Changhai
Project Start
2011-05-01
Project End
2016-04-30
Budget Start
2014-05-01
Budget End
2015-04-30
Support Year
4
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Toledo
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
City
Toledo
State
OH
Country
United States
Zip Code
43614
Hakami, Alqassem Y; Sari, Youssef (2017) ?-Lactamase inhibitor, clavulanic acid, attenuates ethanol intake and increases glial glutamate transporters expression in alcohol preferring rats. Neurosci Lett 657:140-145
Alasmari, Fawaz; Crotty Alexander, Laura E; Nelson, Jessica A et al. (2017) Effects of chronic inhalation of electronic cigarettes containing nicotine on glial glutamate transporters and ?-7 nicotinic acetylcholine receptor in female CD-1 mice. Prog Neuropsychopharmacol Biol Psychiatry 77:1-8
Hammad, Alaa M; Althobaiti, Yusuf S; Das, Sujan C et al. (2017) Effects of repeated cocaine exposure and withdrawal on voluntary ethanol drinking, and the expression of glial glutamate transporters in mesocorticolimbic system of P rats. Mol Cell Neurosci 82:58-65
Alshehri, Fahad S; Althobaiti, Yusuf S; Sari, Youssef (2017) Effects of Administered Ethanol and Methamphetamine on Glial Glutamate Transporters in Rat Striatum and Hippocampus. J Mol Neurosci 61:343-350
Goodwani, Sunil; Saternos, Hannah; Alasmari, Fawaz et al. (2017) Metabotropic and ionotropic glutamate receptors as potential targets for the treatment of alcohol use disorder. Neurosci Biobehav Rev 77:14-31
Hammad, Alaa M; Alasmari, Fawaz; Althobaiti, Yusuf S et al. (2017) Modulatory effects of Ampicillin/Sulbactam on glial glutamate transporters and metabotropic glutamate receptor 1 as well as reinstatement to cocaine-seeking behavior. Behav Brain Res 332:288-298
Hakami, Alqassem Y; Alshehri, Fahad S; Althobaiti, Yusuf S et al. (2017) Effects of orally administered Augmentin on glutamate transporter 1, cystine-glutamate exchanger expression and ethanol intake in alcohol-preferring rats. Behav Brain Res 320:316-322
Sari, Youssef (2017) Commentary: Targeting NMDA Receptor and Serotonin Transporter for the Treatment of Comorbid Alcohol Dependence and Depression. Alcohol Clin Exp Res 41:275-278
Almalki, Atiah H; Das, Sujan C; Alshehri, Fahad S et al. (2017) Effects of sequential ethanol exposure and repeated high-dose methamphetamine on striatal and hippocampal dopamine, serotonin and glutamate tissue content in Wistar rats. Neurosci Lett 665:61-66
Althobaiti, Yusuf S; Alshehri, Fahad S; Almalki, Atiah H et al. (2016) Effects of Ceftriaxone on Glial Glutamate Transporters in Wistar Rats Administered Sequential Ethanol and Methamphetamine. Front Neurosci 10:427

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