LOW LEVEL HYPERBARIC ETHANOL ANTAGONISM

Summary

Principal Investigator: RONALD ALKANA
Abstract: The primary goal is to increase understanding of the initial molecular targets for ethanol ligand-gated ion channels (LGICs). The proposal builds on our previous work which found that increased atmospheric pressure (pressure) antagonizes ethanol at the behavioral, biochemical and molecular levels and indicates that pressure can provide unique insights into the molecular structures on which ethanol acts in LGICs. The proposed work will: 1) Test hypotheses regarding the sites of action of ethanol suggested by our recent findings in glycine receptors (GlyRs) using standard molecular approaches including cysteine mutagenesis and sulfhydryl-specific labeling and 2) Use the unique qualities of pressure antagonism to test hypotheses regarding the sites of action for ethanol in GlyR and other LGICs that are difficult to address with molecular techniques alone. This proposal focuses on GlyR and GABAAR expressed in oocytes using two-electrode voltage clamp and will begin to investigate other LGICs. Confirmatory studies of mutant receptor properties will be conducted in HEK 293 and/or NG 108 cells using whole cell and patch clamp techniques. Aim 1 - Use pressure and molecular manipulations to identify and test novel sites of action for ethanol in GlyRs and GABAARs. Aim 2 - Use pressure to screen for possible structural and/or functional similarities between sites of action for ethanol across LGICs within and outside of the nicotinic cholinergic (Cys-loop) superfamily of LGICs. The proposed work builds on differences we found in sensitivity to pressure antagonism of ethanol between alpha1GlyR (pressure antagonism sensitive) and alpha2GlyR (pressure antagonism insensitive). The findings of Aims I and 2 will be used to modify existing, or to construct new, molecular models of ethanol's sites of action in LGICs. Overall, this work will contribute to our long-term goal, which is to identify specific targets at which therapeutically relevant agents can be directed to reduce the social problems, loss of lives and tremendous economic costs resulting from the misuse and abuse of alcohol.
Funding Period: 2009-07-15 - 2010-06-30
more information: NIH RePORT

Top Publications

  1. pmc Contribution of P2X4 receptors to ethanol intake in male C57BL/6 mice
    Letisha R Wyatt
    Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90033, USA
    Neurochem Res 39:1127-39. 2014
  2. pmc Tryptophan 46 is a site for ethanol and ivermectin action in P2X4 receptors
    MAYA POPOVA
    Alcohol and Brain Research Laboratories, Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90089, USA
    Purinergic Signal 9:621-32. 2013
  3. pmc Charge and geometry of residues in the loop 2 β hairpin differentially affect agonist and ethanol sensitivity in glycine receptors
    Daya I Perkins
    Alcohol and Brain Research Laboratories, Departments of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA
    J Pharmacol Exp Ther 341:543-51. 2012
  4. pmc Ethanol is a fast channel inhibitor of P2X4 receptors
    Olga Ostrovskaya
    Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, University of Southern California, Los Angeles, CA 90033, USA
    J Pharmacol Exp Ther 337:171-9. 2011
  5. pmc Ivermectin antagonizes ethanol inhibition in purinergic P2X4 receptors
    Liana Asatryan
    Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, Los Angeles, California 90033, USA
    J Pharmacol Exp Ther 334:720-8. 2010
  6. pmc Molecular targets and mechanisms for ethanol action in glycine receptors
    Daya I Perkins
    Alcohol and Brain Research Laboratories, Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
    Pharmacol Ther 127:53-65. 2010
  7. pmc A point mutation in the ectodomain-transmembrane 2 interface eliminates the inhibitory effects of ethanol in P2X4 receptors
    MAYA POPOVA
    Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
    J Neurochem 112:307-17. 2010
  8. pmc Loop 2 structure in glycine and GABA(A) receptors plays a key role in determining ethanol sensitivity
    Daya I Perkins
    Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, USA
    J Biol Chem 284:27304-14. 2009
  9. pmc Roles for loop 2 residues of alpha1 glycine receptors in agonist activation
    Daniel K Crawford
    Alcohol and Brain Research Laboratory, Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, USA
    J Biol Chem 283:27698-706. 2008
  10. pmc Roles of ectodomain and transmembrane regions in ethanol and agonist action in purinergic P2X2 and P2X3 receptors
    Liana Asatryan
    Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, University of Southern California, Los Angeles, CA 90033, USA
    Neuropharmacology 55:835-43. 2008

Scientific Experts

  • Liana Asatryan
  • DARYL DAVIES
  • Ronald L Alkana
  • Daya I Perkins
  • Daniel K Crawford
  • James R Trudell
  • MAYA POPOVA
  • Kaixun Li
  • Letisha R Wyatt
  • Olga Ostrovskaya
  • Edward J Bertaccini
  • Sheraz Khoja
  • Megan M Yardley
  • Deborah A Finn
  • RONALD ALKANA
  • James Trudell
  • Robert W Peoples
  • Letisha Wyatt

Detail Information

Publications15

  1. pmc Contribution of P2X4 receptors to ethanol intake in male C57BL/6 mice
    Letisha R Wyatt
    Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90033, USA
    Neurochem Res 39:1127-39. 2014
    ..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. ..
  2. pmc Tryptophan 46 is a site for ethanol and ivermectin action in P2X4 receptors
    MAYA POPOVA
    Alcohol and Brain Research Laboratories, Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90089, USA
    Purinergic Signal 9:621-32. 2013
    ....
  3. pmc Charge and geometry of residues in the loop 2 β hairpin differentially affect agonist and ethanol sensitivity in glycine receptors
    Daya I Perkins
    Alcohol and Brain Research Laboratories, Departments of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA
    J Pharmacol Exp Ther 341:543-51. 2012
    ..This knowledge will help to define the key physical-chemical parameters that cause the actions of ethanol in GlyRs...
  4. pmc Ethanol is a fast channel inhibitor of P2X4 receptors
    Olga Ostrovskaya
    Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, University of Southern California, Los Angeles, CA 90033, USA
    J Pharmacol Exp Ther 337:171-9. 2011
    ..Overall, these findings provide key information regarding the mechanism of ethanol action on ATP-gated currents in P2X4Rs and provide new insights into the biophysical properties of P2X4Rs...
  5. pmc Ivermectin antagonizes ethanol inhibition in purinergic P2X4 receptors
    Liana Asatryan
    Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, Los Angeles, California 90033, USA
    J Pharmacol Exp Ther 334:720-8. 2010
    ..Taken with the building evidence supporting a role for P2X4Rs in ethanol intake, the present findings suggest that the newly identified alcohol pocket is a potential site for development of medication for alcohol use disorders...
  6. pmc Molecular targets and mechanisms for ethanol action in glycine receptors
    Daya I Perkins
    Alcohol and Brain Research Laboratories, Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
    Pharmacol Ther 127:53-65. 2010
    ..Recent molecular models of the sites of ethanol action in GlyRs and their implications to our understanding of possible mechanism of ethanol action and novel targets for drug development in GlyRs are discussed...
  7. pmc A point mutation in the ectodomain-transmembrane 2 interface eliminates the inhibitory effects of ethanol in P2X4 receptors
    MAYA POPOVA
    Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
    J Neurochem 112:307-17. 2010
    ..The results support the proposed hypothesis and represent an important step toward developing ethanol-insensitive receptors for investigating the role of P2X4Rs in mediating behavioral effects of ethanol...
  8. pmc Loop 2 structure in glycine and GABA(A) receptors plays a key role in determining ethanol sensitivity
    Daya I Perkins
    Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, USA
    J Biol Chem 284:27304-14. 2009
    ..In addition to being the first GlyR model threaded on GLIC, the juxtaposition of the two structures led to a possible mechanistic explanation for the effects of ethanol on GlyR-based on changes in Loop 2 structure...
  9. pmc Roles for loop 2 residues of alpha1 glycine receptors in agonist activation
    Daniel K Crawford
    Alcohol and Brain Research Laboratory, Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, USA
    J Biol Chem 283:27698-706. 2008
    ....
  10. pmc Roles of ectodomain and transmembrane regions in ethanol and agonist action in purinergic P2X2 and P2X3 receptors
    Liana Asatryan
    Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, University of Southern California, Los Angeles, CA 90033, USA
    Neuropharmacology 55:835-43. 2008
    ..Overall, these findings are the first to identify potential targets for ethanol in P2X2 and P2X3Rs and should provide insight into the sites of ethanol action in other P2XRs...
  11. ncbi Targets for ethanol action and antagonism in loop 2 of the extracellular domain of glycine receptors
    Daya I Perkins
    Alcohol and Brain Research Laboratory, Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
    J Neurochem 106:1337-49. 2008
    ..These findings should help in the development of pharmacological agents that antagonize ethanol...
  12. ncbi Evidence that ethanol acts on a target in Loop 2 of the extracellular domain of alpha1 glycine receptors
    Daniel K Crawford
    Alcohol and Brain Research Laboratory, Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, USA
    J Neurochem 102:2097-109. 2007
    ....
  13. pmc Effects of ethanol on adenosine 5'-triphosphate-gated purinergic and 5-hydroxytryptamine receptors
    Daryl L Davies
    University of Southern California, Los Angeles, California, USA
    Alcohol Clin Exp Res 30:349-58. 2006
    ..Collectively, the presentations provided strong evidence that P2X and 5-HT3 receptors are important targets for ethanol action...
  14. ncbi Ethanol differentially affects ATP-gated P2X(3) and P2X(4) receptor subtypes expressed in Xenopus oocytes
    Daryl L Davies
    Department of Molecular Pharmacology Toxicology, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90033, USA
    Neuropharmacology 49:243-53. 2005
    ....