The Identification of novel pharmacological approaches to reduce pain is critical from public health perspective. One of the most common reasons to seek medical attention is that of pain, and collectively pain represents a huge financial burden to society. Once thought to be only mediated solely by neuronal firing, the immune system has been revealed to play a critical role in the regulation, maintenance and transition from acute to chronic pain states. One class that has broad immune relevance during periods of pain is the prostaglandins. Recent discoveries yield insight on a novel pathway of diacylglycerol lipase (DAGL) involvement in the ultimate formation of arachidonic acid, which can then be transformed into prostaglandins. In vitro work shows that inhibiting DAGL-?, one form of DAGL, reduces the biosynthesis of 2-arachidonyl glycerol, the endocannabinoid ligand and a precursor of arachidonic acid. This reduction in free arachidonic acid in turn, results in decreases in the formation of the prostaglandin PGE2 and the pro-inflammatory cytokine tumor necrosis factor- alpha (TNF-?). Therefore, we hypothesize that pharmacological inhibition of DAGL-? with a novel compound, KT109, in mice will lower pro-inflammatory cytokines, prostaglandins and other inflammatory mediators of pain, leading to reversal of behaviors associated with pain. Accordingly, the objectives of this training plan are to characterize the ant-pain effects of DAGL-? inhibitors in murine pain models and determine the underlying in vivo mechanism(s) of action of this class of compounds. The proposed aims to examine these objectives are: 1.) Aim 1: Elucidate the consequences of blocking DAGL- ? in inflammatory pain assays. 2.) Determine the locus of action mediating the pain stimulated and pain depressed behavioral effects of DAGL-? inhibitors in the LPS model of inflammatory pain. 3.) Determine the effects of DAGL-? inhibition on pro-inflammatory and pain mediators. Under these aims the consequences of inhibiting DAGL-? will be investigated in the LPS inflammatory pain model, and the importance of prostaglandins and other pro-inflammatory mediators will be identified. This work aiming to identify a novel mechanism of prostaglandin regulation and subsequent pain control will provide a critical training plan for Dr. Wilkerson to gain the necessary bench skills and conceptual framework to become an independent investigator in developing analgesics that lack abuse potential. Ultimately, the knowledge obtained from this research has the potential to establish DAGL-? as a target linking upstream prostaglandin control to pain relief.

Public Health Relevance

Inflammatory modulation has proven to be a major component in states of pain. While targeting some inflammatory mediators has been useful in the current treatments, a need persists for better therapeutics. This research provides a novel pathway of how inhibiting the enzyme DAGL-? may contribute to pain relief.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32DA038493-03
Application #
9222649
Study Section
Special Emphasis Panel (ZRG1-F02B-D (20)L)
Program Officer
Babecki, Beth
Project Start
2015-03-10
Project End
2018-03-09
Budget Start
2017-03-10
Budget End
2018-03-09
Support Year
3
Fiscal Year
2017
Total Cost
$60,990
Indirect Cost
Name
Virginia Commonwealth University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
105300446
City
Richmond
State
VA
Country
United States
Zip Code
23298
Donvito, Giulia; Nass, Sara R; Wilkerson, Jenny L et al. (2018) The Endogenous Cannabinoid System: A Budding Source of Targets for Treating Inflammatory and Neuropathic Pain. Neuropsychopharmacology 43:52-79
Wilkerson, Jenny L; Curry, Zachary A; Kinlow, Pamela D et al. (2018) Evaluation of different drug classes on transient sciatic nerve injury-depressed marble burying in mice. Pain 159:1155-1165
Curry, Zachary A; Wilkerson, Jenny L; Bagdas, Deniz et al. (2018) Monoacylglycerol Lipase Inhibitors Reverse Paclitaxel-Induced Nociceptive Behavior and Proinflammatory Markers in a Mouse Model of Chemotherapy-Induced Neuropathy. J Pharmacol Exp Ther 366:169-183
Wilkerson, Jenny L; Ghosh, Sudeshna; Mustafa, Mohammed et al. (2017) The endocannabinoid hydrolysis inhibitor SA-57: Intrinsic antinociceptive effects, augmented morphine-induced antinociception, and attenuated heroin seeking behavior in mice. Neuropharmacology 114:156-167
Mukhopadhyay, Partha; Baggelaar, Marc; Erdelyi, Katalin et al. (2016) The novel, orally available and peripherally restricted selective cannabinoid CB2 receptor agonist LEI-101 prevents cisplatin-induced nephrotoxicity. Br J Pharmacol 173:446-58
Wilkerson, Jenny L; Niphakis, Micah J; Grim, Travis W et al. (2016) The Selective Monoacylglycerol Lipase Inhibitor MJN110 Produces Opioid-Sparing Effects in a Mouse Neuropathic Pain Model. J Pharmacol Exp Ther 357:145-56
Wilkerson, J L; Ghosh, S; Bagdas, D et al. (2016) Diacylglycerol lipase ? inhibition reverses nociceptive behaviour in mouse models of inflammatory and neuropathic pain. Br J Pharmacol 173:1678-92
Donvito, Giulia; Wilkerson, Jenny L; Damaj, M Imad et al. (2016) Palmitoylethanolamide Reverses Paclitaxel-Induced Allodynia in Mice. J Pharmacol Exp Ther 359:310-318
Bagdas, Deniz; Wilkerson, Jenny L; Kulkarni, Abhijit et al. (2016) The ?7 nicotinic receptor dual allosteric agonist and positive allosteric modulator GAT107 reverses nociception in mouse models of inflammatory and neuropathic pain. Br J Pharmacol 173:2506-20