The endogenous cannabinoids and their attending G protein-coupled receptors are components of a neuromodulatory system that regulates multiple brain functions, including pain and reward. The endocannabinoid anandamide is released from neurons upon demand and undergoes a rapid deactivation process that is thought to involve two sequential steps: carrier-mediated transport into cells and intracellular hydrolysis by fatty acid amide hydrolase-1 (FAAH-1) and FAAH-2. The main objective of the present application is to address two key aspects of anandamide deactivation, which remain incompletely understood: (i) the mechanism and significance of anandamide transport;and (ii) the roles of FAAH-mediated anandamide hydrolysis outside the central nervous system (CNS). In previous studies, funded by this grant, we developed the first brain-impermeant FAAH inhibitor and showed that this O-aryl carbamate derivative (termed URB937) suppresses acute and chronic pain-related responses in rodents by enhancing the intrinsic activity of anandamide at CB1-type cannabinoid receptors located outside the CNS. Furthermore, we molecularly cloned a catalytically defective variant of FAAH-1 (termed FAAH-Like Anandamide Transporter, FLAT) that lacks amidase activity, but selectively binds to anandamide and facilitates the transport of this compound into cells. Finally, we discovered a ligand (ARN272) that inhibits anandamide binding to FLAT, blocks anandamide transport in vitro and interrupts anandamide deactivation in vivo. The present proposal has two primary aims.
Aim 1 : To define pharmacophore profiles for peripheral FAAH inhibition and identify new brain-impermeant FAAH inhibitors. We will synthesize analogs of URB937 to (i) determine structure-activity relationships for peripheral segregation within the O-aryl carbamate chemotype;and (ii) identify new brain-impermeant FAAH inhibitors, which may be utilized both to investigate the functions of peripheral FAAH and as prototypes for analgesic agents devoid of central side effects.
Aim 2 : To characterize the role of FLAT in neuronal anandamide transport and discover potent and selective FLAT inhibitors. We will perform three sets of studies: (a) we will conduct computational and mutational analyses aimed at exploring the molecular mechanism(s) through which substrates (such as anandamide) and inhibitors (such as ARN272) interact with FLAT;(b) we will investigate the mechanism through which FLAT mediates anandamide transport;and (c) we will use the scaffold of ARN272 to create novel FLAT ligands that may serve as tools to investigate the functions of FLAT in anandamide transport. These studies are likely to generate new molecular tools that will help elucidate the mechanism of anandamide deactivation and may lead to the discovery of new drug candidates for pain, substance abuse and other human diseases.

Public Health Relevance

The human body produces marijuana-like molecules, called endocannabinoids, which are involved in the regulation of pain, mood, memory and addiction. We propose to create potent and selective chemical probes that will allow researchers to investigate how brain cells stop the actions of the endocannabinoids. These chemicals may not only be useful as experimental tools, but might also help us discover innovative therapies to treat drug abuse, pain and other diseases.

National Institute of Health (NIH)
National Institute on Drug Abuse (NIDA)
Research Project (R01)
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Molecular Neuropharmacology and Signaling Study Section (MNPS)
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Rapaka, Rao
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University of California Irvine
Anatomy/Cell Biology
Schools of Medicine
United States
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Fiasella, Annalisa; Nuzzi, Andrea; Summa, Maria et al. (2014) 3-Aminoazetidin-2-one derivatives as N-acylethanolamine acid amidase (NAAA) inhibitors suitable for systemic administration. ChemMedChem 9:1602-14
Bandiera, Tiziano; Ponzano, Stefano; Piomelli, Daniele (2014) Advances in the discovery of N-acylethanolamine acid amidase inhibitors. Pharmacol Res 86:11-7
Piomelli, Daniele (2014) More surprises lying ahead. The endocannabinoids keep us guessing. Neuropharmacology 76 Pt B:228-34
Piomelli, Daniele; Sasso, Oscar (2014) Peripheral gating of pain signals by endogenous lipid mediators. Nat Neurosci 17:164-74
Moreno-Sanz, Guillermo; Barrera, Borja; Armirotti, Andrea et al. (2014) Structural determinants of peripheral O-arylcarbamate FAAH inhibitors render them dual substrates for Abcb1 and Abcg2 and restrict their access to the brain. Pharmacol Res 87:87-93
Sasso, Oscar; Moreno-Sanz, Guillermo; Martucci, Cataldo et al. (2013) Antinociceptive effects of the N-acylethanolamine acid amidase inhibitor ARN077 in rodent pain models. Pain 154:350-60
O'Brien, L D; Limebeer, C L; Rock, E M et al. (2013) Anandamide transport inhibition by ARN272 attenuates nausea-induced behaviour in rats, and vomiting in shrews (Suncus murinus). Br J Pharmacol 170:1130-6
Bertolacci, Laura; Romeo, Elisa; Veronesi, Marina et al. (2013) A binding site for nonsteroidal anti-inflammatory drugs in fatty acid amide hydrolase. J Am Chem Soc 135:22-5
Lodola, Alessio; Capoferri, Luigi; Rivara, Silvia et al. (2013) Quantum mechanics/molecular mechanics modeling of fatty acid amide hydrolase reactivation distinguishes substrate from irreversible covalent inhibitors. J Med Chem 56:2500-12
Moreno-Sanz, Guillermo; Duranti, Andrea; Melzig, Laurin et al. (2013) Synthesis and structure-activity relationship studies of O-biphenyl-3-yl carbamates as peripherally restricted fatty acid amide hydrolase inhibitors. J Med Chem 56:5917-30

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