Expression of ecto-ATPase NTPDase2 in human dental pulp

J Dent Res. 2012 Mar;91(3):261-7. doi: 10.1177/0022034511431582. Epub 2011 Dec 14.

Abstract

Dental pulpal nerve fibers express ionotropic adenosine triphosphate (ATP) receptors, suggesting that ATP signaling participates in the process of dental nociception. In this study, we investigated if the principal enzymes responsible for extracellular ATP hydrolysis, namely, nucleoside triphosphate diphosphohydrolases (NTPDases), are present in human dental pulp. Immunohistochemical and immunofluorescence experiments showed that NTPDase2 was predominantly expressed in pulpal nerve bundles, Raschkow's nerve plexus, and in the odontoblast layer. NTPDase2 was expressed in pulpal Schwann cells, with processes accompanying the nerve fibers and projecting into the odontoblast layer. Odontoblasts expressed the gap junction protein, connexin43, which can form transmembrane hemichannels for ATP release. NTPDase2 was localized close to connexin43 within the odontoblast layer. These findings provide evidence for the existence of an apparatus for ATP release and degradation in human dental pulp, consistent with the involvement of ATP signaling in the process of dentin sensitivity and dental pain.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / biosynthesis*
  • Adenosine Triphosphatases / physiology
  • Connexin 43 / biosynthesis*
  • Dental Pulp / cytology
  • Dental Pulp / enzymology*
  • Dental Pulp / innervation
  • Dentin Sensitivity / etiology*
  • Dentin Sensitivity / metabolism
  • Humans
  • Molar, Third
  • Odontoblasts / enzymology
  • Odontoblasts / metabolism
  • Schwann Cells / enzymology
  • Signal Transduction
  • Toothache / etiology*
  • Toothache / metabolism
  • Vimentin / biosynthesis

Substances

  • Connexin 43
  • Vimentin
  • Adenosine Triphosphatases
  • ectoATPase