title: Diacylglycerol lipase β inhibition reverses nociceptive behaviour in mouse models of inflammatory and neuropathic pain.
abstract: Inhibition of diacylglycerol lipase (DGL)β prevents LPS-induced pro-inflammatory responses in mouse peritoneal macrophages. Thus, the present study tested whether DGLβ inhibition reverses allodynic responses of mice in the LPS model of inflammatory pain, as well as in neuropathic pain models.
  
  
  
  Initial experiments examined the cellular expression of DGLβ and inflammatory mediators within the LPS-injected paw pad. DAGL-β (-/-) mice or wild-type mice treated with the DGLβ inhibitor KT109 were assessed in the LPS model of inflammatory pain. Additional studies examined the locus of action for KT109-induced antinociception, its efficacy in chronic constrictive injury (CCI) of sciatic nerve and chemotherapy-induced neuropathic pain (CINP) models.
  
  
  
  Intraplantar LPS evoked mechanical allodynia that was associated with increased expression of DGLβ, which was co-localized with increased TNF-α and prostaglandins in paws. DAGL-β (-/-) mice or KT109-treated wild-type mice displayed reductions in LPS-induced allodynia. Repeated KT109 administration prevented the expression of LPS-induced allodynia, without evidence of tolerance. Intraplantar injection of KT109 into the LPS-treated paw, but not the contralateral paw, reversed the allodynic responses. However, i.c.v. or i.t. administration of KT109 did not alter LPS-induced allodynia. Finally, KT109 also reversed allodynia in the CCI and CINP models and lacked discernible side effects (e.g. gross motor deficits, anxiogenic behaviour or gastric ulcers).
  
  
  
  These findings suggest that local inhibition of DGLβ at the site of inflammation represents a novel avenue to treat pathological pain, with no apparent untoward side effects.
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Wilkerson
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA.|Experimental Animals Breeding and Research Center, Faculty of Medicine, Uludag University, Bursa, Turkey.
authors.forename: D
authors.initials: D
authors.lastname: Bagdas
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: B L
authors.initials: BL
authors.lastname: Mason
authors.affiliation: Department of Psychology, West Virginia University, Morgantown, WV, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Crowe
authors.affiliation: The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Hsu
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: L E
authors.initials: LE
authors.lastname: Wise
authors.affiliation: Department of Psychology, West Virginia University, Morgantown, WV, USA.
authors.forename: S G
authors.initials: SG
authors.lastname: Kinsey
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: M I
authors.initials: MI
authors.lastname: Damaj
authors.affiliation: The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA.
authors.forename: B F
authors.initials: BF
authors.lastname: Cravatt
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Lichtman
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D007249:Inflammation / Q000188:drug therapy* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008071:Lipoprotein Lipase / Q000037:antagonists & inhibitors* / Q000172:deficiency / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009437:Neuralgia / Q000188:drug therapy* / Q000378:metabolism; D059225:Nociception / Q000187:drug effects*; D013329:Structure-Activity Relationship
chemical_list: D004791:Enzyme Inhibitors; D008070:Lipopolysaccharides; D008071:Lipoprotein Lipase; C577904:diacylglycerol lipase beta, mouse