Development of a Novel Class for Opioid Drugs

Award Information
Agency: Department of Health and Human Services
Branch: N/A
Contract: 1R41DA032293-01
Agency Tracking Number: R41DA032293
Amount: $656,967.00
Phase: Phase I
Program: STTR
Awards Year: 2012
Solicitation Year: 2012
Solicitation Topic Code: NIDA
Solicitation Number: PA10-051
Small Business Information
208 N. Columbia St., Ste 300, CHAPEL HILL, NC, -
DUNS: 602754017
HUBZone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: N
Principal Investigator
 (919) 843-2549
Business Contact
Phone: (919) 261-7886
Research Institution
Office of Sponsored Research 104 Airport Drive CB#1350
 () -
 Nonprofit college or university
DESCRIPTION (provided by applicant): The mu-opioid receptor (MOR) is the primary target for opioid analgesics. While opioids are the most frequently used and effective analgesics for the treatment of moderate to severe clinical pain, their prolonged use leads to reduced efficacy and a number of adverse side effects, including post dosing-induced hyperalgesia and analgesic tolerance. MOR induces analgesia through several mechanisms including the inhibition of second messenger pathways and modulation of ion channel activity. Nevertheless, the opposite, opioid induced cellular excitation, has also been demonstrated and proposed to mediate reductions in efficacy, tolerance, and opioid-induced hyperalgesia following the exposure to opioids. While an array of mechanisms has been advanced that contribute to these use-dependence changes in MOR-mediated effects, we have recently identified a novel mechanism underlying the shift in MOR signaling: a MOR splice variant encoding a functional 6 transmembrane (6TM) receptor. This 6TM isoform was identified in a study designed to determine the genetic basis for variability in sensitivity to exogenous opiates. Importantly, morphine exposure to cells overexpressing the 6TM receptor isoform leads to excitatory cellular effects rather than the classic inhibitory effects that are produced by stimulating the canonical 7TM MOR isoform. The discovery of this new alternative 6TM isoform, which evokes responses that oppose the biological effects of the major 7TM isoform, provides a unique opportunity to identify pharmacological probes that will further our understanding of the mechanisms that mediate the pharmacodynamic effects of opioids and will enable the future development of new opioid compounds that show 7TM agonist and/or 6TM antagonist properties providing high analgesic efficacy with a diminished ability to produce post dosing-induced hyperalgesia, analgesic tolerance, and unwanted physiological side effects. To take maximal advantage of this opportunity, an interdisciplinary investigative team with unique, but complementary, areas of expertise has been assembled to develop, validate and characterize the in silico models of the major 7TM and alternative 6TM receptor isoforms can be used to identity putative isoform selective compounds. The long-term goal of this effort is to develop novel opioids that evoke high potency analgesia without deleterious short- or long-term consequences. PUBLIC HEALTH RELEVANCE: While opioids are the most frequently used and effective analgesicsfor the treatment of moderate to severe clinical pain, their prolonged use leads to a number of treatment limiting side-effects in a large percentage of patients. An experienced multidisciplinary investigative team proposes a set of studies that have derived from new data on the molecular and signaling basis of opioid receptor pharmacology and associated side-effects. These studies will build in silico models of the human 5-opioid receptor isoforms whose activities differentially contribute to the clinicalefficacy of opioids and allow identification of novel and potentially a new class of opioid compounds that will show high analgesic properties with a diminished ability to produce opioid-induced hyperalgesia, analgesic tolerance, and unwanted physiologicalside effects.

* information listed above is at the time of submission.

Agency Micro-sites

SBA logo
Department of Agriculture logo
Department of Commerce logo
Department of Defense logo
Department of Education logo
Department of Energy logo
Department of Health and Human Services logo
Department of Homeland Security logo
Department of Transportation logo
Environmental Protection Agency logo
National Aeronautics and Space Administration logo
National Science Foundation logo
US Flag An Official Website of the United States Government