title: Expression of Cannabinoid Type 1 Receptors in Human Odontoblast Cells.
abstract: BACKGROUND
  The aim of this study was to investigate the functional expression of cannabinoid type 1 (CB1) receptors in human odontoblasts (HODs) and the possible internal mechanism.
  
  
  METHODS
  In the present study, we examined the molecular and functional expression of the CB1 receptors in cultured HOD-like cells and native HODs obtained from healthy wisdom teeth.
  
  
  RESULTS
  Immunohistochemistry and immunofluorescence revealed that CB1 receptors localize to native HODs and HOD-like cells, respectively. Both reverse-transcription polymerase chain reaction and Western blot analysis confirmed gene and protein expression of CB1 receptors. The ultrastructural distribution by immunoelectron microscopy also found that CB1 receptors labeled by colloidal gold particles distribute sparsely in the cytoplasm and odontoblastic processes. In functional assays, 2-arachidonyl glycerol, as an agonist of CB receptors, elicited the increase of intracellular fluorescence intensity that could be inhibited by a CB1-specific receptor antagonist rather than a selective CB2 receptor antagonist with fluo-3AM Ca2+fluorescence. The source of the increase of intracellular fluorescence intensity elicited by CB1 receptors was from extracellular Ca2+but not intracellular Ca2+stores. The process of 2-arachidonyl glycerol activating CB1 receptors modulated transient receptor potential vanilloid 1-mediated Ca2+entry via the cyclic adenosine monophosphate signaling pathway.
  
  
  CONCLUSIONS
  We conclude that HODs can express functional CB1 receptors that may play an important role in mediating the physiological function in tooth pulp.
authors.affiliation: Department of Endodontics, College of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Kehua
authors.initials: K
authors.lastname: Que
authors.affiliation: Department of Endodontics, College of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Dan
authors.initials: D
authors.lastname: He
authors.affiliation: Department of Endodontics, Wuxi Stomatology Hospital, Jiangsu, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Endodontics, College of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Ligeng
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Endodontics, College of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Endodontics, College of Stomatology, Tianjin Medical University, Tianjin, China.
authors.forename: Zhiying
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Implant, Stomatology College of Nan Kai University, Tianjin, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Periodontics, College of Stomatology, Tianjin Medical University, Tianjin, China. Electronic address: kque@tmu.edu.cn.
authors.forename: Jiayin
authors.initials: J
authors.lastname: Deng
mesh_terms: D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D006801:Humans; D009804:Odontoblasts / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism*
chemical_list: D043884:Receptor, Cannabinoid, CB1; D002118:Calcium
keywords: Cannabinoid type 1 receptors; functional expression; human odontoblasts; transient receptor potential vanilloid 1 channels