This study will determine the molecular mechanism responsible for c-Jun N-terminal kinase (JNK)-mediated tolerance to delta9-THC. We have produced mutant mice (S426A/S430A) expressing a mutant form of the cannabinoid receptor 1 (CB1) that causes delayed tolerance for delta9THC. However, S426A/S430A mutants eventually become completely tolerant to delta9-THC. Tolerance to the analgesic effects of delta9-THC was eliminated by pre-treatment of S426A/S430A mutants with SP600125, an inhibitor JNK. However, the mechanism responsible for JNK-mediated delta9-THC tolerance is not known. This study will determine whether JNK- mediated delta9-THC tolerance is due to CB1 desensitization, down-regulation, or a combination of both. This question will be answered using HU-210-stimulated [35S]GTPgS binding assays, [3H]SR141716A binding assays, and adenylyl cyclase activity assays. Since my lab does not currently employ these techniques, a central component of this K01 is to learn these assays from Dr. Lakshmi Devi's group and implement them in my laboratory. Currently, my laboratory is well equipped to measure tolerance to the behavioral and physiological effects of cannabinoids. However, our competitiveness for R01 funding will require the implementation of these assays, which represent the gold standards for assessing G protein-coupled receptor (GPCR) desensitization and down-regulation. During this award, Dr. Devi and Dr. Richard Mailman, two experts in the field of GPCR signaling, will provide outstanding co-mentorship as I transition towards full independence and develop a fully funded academic research lab. I have been awarded a Junior Faculty Scholar Research Award (JFRSA) from Penn State and have also been provided with excellent start-up funding and research space from my department. As part of the JFRSA, I receive additional outstanding mentorship from an in-house team of mentors including Drs. Kent Vrana, Richard Mailman, Andras Hajnal, and Victor Ruiz-Velasco. The research objectives of this K01 award are to: 1) determine the molecular mechanisms responsible for JNK-mediated delta9- THC tolerance, 2) determine which form of JNK is responsible for desensitization and/or down-regulation of CB1, and 3) incorporate HU-210-stimulated [ S]GTPupsilonS binding, adenylyl cyclase activity, and [ H]SR141716A 35 3 binding assays into my laboratory's technological repertoire.

Public Health Relevance

We have found that tolerance to the analgesic effects of delta9-THC are blocked by pharmacological inhibition of c-Jun N-terminal kinase (JNK) in S426A/S430A mutant mice that are unable to undergo G protein-coupled receptor kinase and betaarrestin-mediated desensitization. This study will determine whether tolerance for delta9-THC is caused by JNK-mediated desensitization or down-regulation of CB1. This study will also determine the form of JNK that is responsible for CB1 desensitization and/or down-regulation.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Scientist Development Award - Research & Training (K01)
Project #
1K01DA037355-01A1
Application #
8821286
Study Section
Molecular Neuropharmacology and Signaling Study Section (MNPS)
Program Officer
Purohit, Vishnudutt
Project Start
2015-02-01
Project End
2018-01-31
Budget Start
2015-02-01
Budget End
2016-01-31
Support Year
1
Fiscal Year
2015
Total Cost
$157,446
Indirect Cost
$9,766
Name
Pennsylvania State University
Department
Anesthesiology
Type
Schools of Medicine
DUNS #
129348186
City
Hershey
State
PA
Country
United States
Zip Code
17033
LaFleur, Rebecca A; Wilson, Ronald P; Morgan, Daniel J et al. (2018) Sex differences in antinociceptive response to ?-9-tetrahydrocannabinol and CP 55,940 in the mouse formalin test. Neuroreport 29:447-452
Berezniuk, Iryna; Rodriguiz, Ramona M; Zee, Michael L et al. (2017) ProSAAS-derived peptides are regulated by cocaine and are required for sensitization to the locomotor effects of cocaine. J Neurochem 143:268-281
Marcus, David J; Henderson-Redmond, Angela N; Gonek, Maciej et al. (2017) Mice expressing a ""hyper-sensitive"" form of the CB1 cannabinoid receptor (CB1) show modestly enhanced alcohol preference and consumption. PLoS One 12:e0174826
Henderson-Redmond, Angela N; Yuill, Matthew B; Lowe, Tammy E et al. (2016) Morphine-induced antinociception and reward in ""humanized"" mice expressing the mu opioid receptor A118G polymorphism. Brain Res Bull 123:5-12
Yuill, Matthew B; Zee, Michael L; Marcus, David et al. (2016) Tolerance to the antinociceptive and hypothermic effects of morphine is mediated by multiple isoforms of c-Jun N-terminal kinase. Neuroreport 27:392-6
Henderson-Redmond, Angela N; Guindon, Josée; Morgan, Daniel J (2016) Roles for the endocannabinoid system in ethanol-motivated behavior. Prog Neuropsychopharmacol Biol Psychiatry 65:330-9
Marcus, David J; Zee, Michael; Hughes, Alex et al. (2015) Tolerance to the antinociceptive effects of chronic morphine requires c-Jun N-terminal kinase. Mol Pain 11:34