This proposal investigates the factors that contribute to sex-differences in molecular, cellular, and function properties in peripheral opioid receptor (POR) systems. We will focus on examining novel mechanisms by which sex-differences in peripherally applied opioid agonists are expressed in the context of inflammatory muscle pain conditions. The central hypotheses of this project are that sex-differences in POR mechanisms are expressed at multiple levels in primary afferent signaling process and injury or inflammation differentially impacts POR signaling between the sexes. Studies will determine whether there are sex-differences in (1) expression levels of the three subtypes of ORs, <, 4, and : ORs;(2) sub-cellular localizations of the three OR subtypes;and (3) the expression of major downstream targets, G-protein coupled and ATP dependent inward rectifying potassium channels (GIRK and KATP), under normal and inflammatory conditions. Each of these studies will be accompanied by behavioral tests to assess functional relevance of molecular and cellular changes. These studies bear high clinical significance since the pain and management involving masticatory muscles and TMJ, such as in TMJMD, are sexually dimorphic, and since there is increasing clinical as well as pre-clinical evidence that indicate PORs as potential therapeutic targets for treating various types of chronic pain conditions. Understanding mechanic bases for sex-differences in POR function will help develop sex-specific management strategies for persistent types of orofacial muscle pain.

Public Health Relevance

This project examines novel mechaisms that may underlie sexual dimorphism in peripheral opioid receptor (POR) effects in the context of inflammatory msucle pain conditions. PORs, namely, mu, delta and kappa ORs, are being increasingly recognized as important therapeutic targets that mediate anti-nociception and/or anti-hyperlagesia in inflammatory pain conditions without producing centrally-mediated side effects. Many types of chronic pain conditions such as temporomandibular joint muscle disorders (TMJMD) exhibit sexually dimorphic pain and analgesic responses. Therefore, outcomes of this project can offer important new insights for the development of mechanism-based sex-specific treatment alternatives that can be directed at the peripheral opioid receptor system to ameliorate persistent orofacial muscle pain.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE019448-05
Application #
8284212
Study Section
Somatosensory and Chemosensory Systems Study Section (SCS)
Program Officer
Kusiak, John W
Project Start
2008-09-30
Project End
2014-06-30
Budget Start
2012-07-01
Budget End
2014-06-30
Support Year
5
Fiscal Year
2012
Total Cost
$349,161
Indirect Cost
$116,387
Name
University of Maryland Baltimore
Department
Microbiology/Immun/Virology
Type
Schools of Dentistry
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Kang, Soo-Kyung; Lee, Yeon-Hee; Park, Hyeji et al. (2018) Effects of intramuscular morphine in men and women with temporomandibular disorder with myofascial pain. Oral Dis 24:1591-1598
Lee, Ki Seok; Zhang, Youping; Asgar, Jamila et al. (2016) Androgen receptor transcriptionally regulates ?-opioid receptor expression in rat trigeminal ganglia. Neuroscience 331:52-61
Auh, Q-Schick; Chun, Yang Hyun; Melemedjian, Ohannes K et al. (2016) Peripheral interactions between cannabinoid and opioid receptor agonists in a model of inflammatory mechanical hyperalgesia. Brain Res Bull 125:211-7
Asgar, J; Zhang, Y; Saloman, J L et al. (2015) The role of TRPA1 in muscle pain and mechanical hypersensitivity under inflammatory conditions in rats. Neuroscience 310:206-15
Zhang, X; Zhang, Y; Asgar, J et al. (2014) Sex differences in ?-opioid receptor expression in trigeminal ganglia under a myositis condition in rats. Eur J Pain 18:151-61
Chung, M-K; Cho, Y S; Bae, Y C et al. (2014) Peripheral G protein-coupled inwardly rectifying potassium channels are involved in ?-opioid receptor-mediated anti-hyperalgesia in rat masseter muscle. Eur J Pain 18:29-38
Lee, K S; Asgar, J; Zhang, Y et al. (2013) The role of androgen receptor in transcriptional modulation of cannabinoid receptor type 1 gene in rat trigeminal ganglia. Neuroscience 254:395-403
Auh, Q-Schick; Ro, Jin Y (2012) Effects of peripheral ýý opioid receptor activation on inflammatory mechanical hyperalgesia in male and female rats. Neurosci Lett 524:111-5
Niu, Katelyn Y; Zhang, Youping; Ro, Jin Y (2012) Effects of gonadal hormones on the peripheral cannabinoid receptor 1 (CB1R) system under a myositis condition in rats. Pain 153:2283-91
Niu, K; Saloman, J L; Zhang, Y et al. (2011) Sex differences in the contribution of ATP-sensitive K+ channels in trigeminal ganglia under an acute muscle pain condition. Neuroscience 180:344-52

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