Summary of the probe development efforts to identify inverse agonists of heterodimerization of the mu 1 (OPRM1) and delta 1 (OPRD1) opioid receptors
Name: Summary of the probe development efforts to identify inverse agonists of heterodimerization of the mu 1 (OPRM1) and delta 1 (OPRD1) opioid receptors. ..more
Source (MLPCN Center Name): The Scripps Research Institute Molecular Screening Center (SRIMSC)
Affiliation: The Scripps Research Institute, TSRI
Assay Provider: Lakshmi A. Devi, Mount Sinai School of Medicine
Network: Molecular Library Probe Production Centers Network (MLPCN)
Grant Proposal Number: R03NS053751
Grant Proposal PI: Lakshmi A. Devi, Mount Sinai School of Medicine
External Assay ID: OPRM1-OPRD1_IAG_SUMMARY
Name: Summary of the probe development efforts to identify inverse agonists of heterodimerization of the mu 1 (OPRM1) and delta 1 (OPRD1) opioid receptors.
Opiates such as morphine are the choice analgesic in the treatment of chronic pain due to their potent and rapid action. However, their long-term use is limited because of the development of tolerance and dependence, as well as respiratory suppression and constipation (1). Due to their clinical importance, various strategies have been considered for making opiates more effective while curbing liabilities such as addiction. One such strategy has been to use a combination of drugs to improve the effectiveness of morphine. The OPRM1 gene encodes the mu opioid receptor, which is the primary site of action for morphine (2) and other commonly used opioid such as heroin, fentanyl, and methadone. OPRM1 activation and subsequent dissociation of the Gi/Go G-proteins results in reduction of adenylyl cyclase-mediated cAMP production (3). There are at least two other types of opioid receptors: delta (OPRD1) and kappa (OPRK1), each with a distinct pharmacologic profile. In particular, delta (OPRD1) opioid receptor ligands have been useful in enhancing morphine's potency, but the underlying molecular basis is not understood (4). It has been shown that modulation of receptor function by physical association between mu and delta opioid receptors is a potential mechanism (5). The assay provider has previously found that a combination of OPRM1 agonist with OPRD1 antagonist selectively activates the OPRM1-OPRD1 heteromer (5) and recently showed that this could be blocked by antibodies that selectively recognize the heteromer (6). Since OPRD1 antagonist have anxiogenic effects, these are not ideal as therapies. Hence, the identification of compounds that selectively modulate mu-delta opioid receptor heterodimerization may have potential in the treatment of pain and alleviate unwanted effects associated with opiate use.
Summary of Probe Development Effort:
This probe development effort is focused on the identification of inverse agonists of heterodimerization of the mu 1 (OPRM1) and delta 1 (OPRD1) opioid receptors. All AIDs that contain results associated with this project can be found in the "Related Bioassays" section of this Summary AID.
1. Raehal KM, Bohn LM. Mu opioid receptor regulation and opiate responsiveness. AAPS J. 2005 Oct 19;7(3):E587-91.
2. Matthes H, Maldonado R, Simonin F, Valverde O, Slowe S, Kitchen I, Befort K, Dierich A, Le Meur M, Dolle P, Tzavara E, Hanoune J, Roques B, Kieffer B (1996) Loss of morphine-induced analgesia, reward effect and withdrawal symptoms in mice lacking the mu-opioid-receptor gene. Nature 383:819-823.
3. Maguea SD and Blendy JAOPRM1 SNP (A118G): Involvement in disease development, treatment response, and animal models. Drug and Alcohol Dependence. 2010 May 108 (3): 172-182.
4. Traynor J, Elliot J. Delta-opioid receptor subtypes and cross talk with mu-receptors. Trends Pharmacol Sci 1993 14:84-86.
5. Gomes I, Jordan BA, Gupta A, Trapaidze N, Nagy V, Devi LA. Heterodimerization of mu and delta opioid receptors: A role in opiate synergy. J Neurosci. 2000 Nov 15;20(22):RC110.
6. Gupta, A., Mulder, J., Gomes, I., Rozenfeld, R., Bushlin, I., Ong, E., Lim, M., Maillet, E., Junek, M., Cahill, C.M., Harkany, T. Devi, L.A. Increased abundance of opioid receptor heteromers after chronic morphine administration. Science Signaling 3:ra54, 2010
Summary, Summary AID, OPRM1, MOR-1, mu, delta, OPRD1, opioid, receptor, GPCR, beta-arrestin, U2OS, PathHunter, complementation, reconstitution, enzyme, beta-gal, beta-galactosidase, lumi, luminescence, luminescent, chemiluminescence, inverse agonist, inhibit, inhibitor, dimer, heterodimer, homodimer, pain, Primary screen, HTS, high throughput screen, 1536, Scripps Florida, The Scripps Research Institute Molecular Screening Center, SRIMSC, Molecular Libraries Probe Production Centers Network, MLPCN.