A large number of physiological processes are controlled by the endogenous cannabinoids. Most of these effects have been attributed to action at either the cannabinoid CB1 or CB2 receptors. Yet there are effects that clearly are not CB1- or CB2-mediated which may not be receptor mediated, but there is also sufficient evidence to suggest the involvement of the vanilloid receptor (TRPV1) in cannabinoid effects and at least two other cannabinoid receptor subtypes defined only pharmacologically until now. Very recently, two orphan G-protein coupled receptors (GPCRs), GPR35 and GPR55, have been suggested to be cannabinoid receptors, with a fairly wide range of cannabinoid ligands reported to display affinity/efficacy at each. We have cloned and expressed both GPR35 and GPR55 and our preliminary studies confirm that they are activated by multiple cannabinoid compounds. In work proposed here, we plan to characterize these two GPCRs through ligand binding and functional studies. Recently developed computer models of GPR35 and GPR55 in their inactive and activated states will be used to guide mutation studies of each receptor. These models are informed by our extensive modeling and mutation experience with the cannabinoid CB1 and CB2 receptors. The goal of mutation studies will be not only to identify residues involved in ligand recognition, but also those residues important for receptor activation. In GPR35 and GPR55 ligand recognition studies, the involvement of specific amino acids with specific ligand functional groups will be tested using carefully chosen compounds. Results of mutation studies in vitro will be used to refine computer receptor models, such that at any given time, these models reflect the current state of knowledge in the field. Because work thus far on GPR35 and GPR55 has not identified a high affinity antagonist for either receptor and because such antagonists would be very valuable tools for studying these two receptors, another goal of the proposed work will be to design antagonists for each receptor sub-type. These compounds will be designed at UNCG (Reggio), synthesized at Research Triangle Institute (Seltzman), and evaluated at CPMCRI (Abood). High affinity antagonists that emerge from this work will be radiolabeled and made available to the scientific community. Determining the distribution of GPR35 and signal transduction pathways of GPR35 and GPR55 will help define their physiological and pathophysiological roles.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA023204-05
Application #
8065417
Study Section
Special Emphasis Panel (ZRG1-MDCN-C (03))
Program Officer
Hillery, Paul
Project Start
2008-07-15
Project End
2012-05-31
Budget Start
2011-06-01
Budget End
2012-05-31
Support Year
5
Fiscal Year
2011
Total Cost
$308,851
Indirect Cost
Name
Temple University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
057123192
City
Philadelphia
State
PA
Country
United States
Zip Code
19122
Fakhouri, Lara; Cook, Christopher D; Al-Huniti, Mohammed H et al. (2017) Design, synthesis and biological evaluation of GPR55 agonists. Bioorg Med Chem 25:4355-4367
Gherghina, Florin Liviu; Tica, Andrei Adrian; Deliu, Elena et al. (2017) Effects of VPAC1 activation in nucleus ambiguus neurons. Brain Res 1657:297-303
Brailoiu, G Cristina; Deliu, Elena; Barr, Jeffrey L et al. (2017) HIV Tat excites D1 receptor-like expressing neurons from rat nucleus accumbens. Drug Alcohol Depend 178:7-14
Lingerfelt, Mary A; Zhao, Pingwei; Sharir, Haleli P et al. (2017) Identification of Crucial Amino Acid Residues Involved in Agonist Signaling at the GPR55 Receptor. Biochemistry 56:473-486
Abdalhameed, Manahil M; Zhao, Pingwei; Hurst, Dow P et al. (2017) Structure-activity relationships of benzothiazole GPR35 antagonists. Bioorg Med Chem Lett 27:612-615
Howlett, Allyn C; Abood, Mary E (2017) CB1 and CB2 Receptor Pharmacology. Adv Pharmacol 80:169-206
Bertini, Simone; Chicca, Andrea; Gado, Francesca et al. (2017) Novel analogs of PSNCBAM-1 as allosteric modulators of cannabinoid CB1 receptor. Bioorg Med Chem 25:6427-6434
Console-Bram, Linda; Ciuciu, Sandra M; Zhao, Pingwei et al. (2017) N-arachidonoyl glycine, another endogenous agonist of GPR55. Biochem Biophys Res Commun 490:1389-1393
Meza-AviƱa, Maria Elena; Lingerfelt, Mary A; Console-Bram, Linda M et al. (2016) Design, synthesis, and analysis of antagonists of GPR55: Piperidine-substituted 1,3,4-oxadiazol-2-ones. Bioorg Med Chem Lett 26:1827-1830
Gamage, Thomas F; Anderson, Johnathon C; Abood, Mary E (2016) CB1 allosteric modulator Org27569 is an antagonist/inverse agonist of ERK1/2 signaling. Cannabis Cannabinoid Res 1:272-280

Showing the most recent 10 out of 30 publications