Odontoblasts in developing, mature and ageing rat teeth have multiple phenotypes that variably express all nine voltage-gated sodium channels

Arch Oral Biol. 2011 Nov;56(11):1199-220. doi: 10.1016/j.archoralbio.2011.04.014.

Abstract

Objective: Our goal was to evaluate the expression patterns for voltage gated sodium channels in odontoblasts of developing and mature rat teeth.

Design: We analysed immunoreactivity (IR) of the alpha subunit for all nine voltage gated sodium channels (Nav1.1-1.9) in teeth of immature (4 weeks), young adult (7 weeks), fully mature adult (3 months), and old rats (6-12 months). We were interested in developmental changes, crown/root differences, tetrodotoxin sensitivity or resistance, co-localization with nerve regions, occurrence in periodontium, and coincidence with other expression patterns by odontoblasts such as for transient receptor potential A1 (TRPA1).

Results: We found that Nav1.1-1.9-IR each had unique odontoblast patterns in mature molars that all differed from developmental stages and from incisors. Nav1.4- and Nav1.7-IR were intense in immature odontoblasts, becoming limited to specific zones in adults. Crown odontoblasts lost Nav1.7-IR and gained Nav1.8-IR where dentine became innervated. Odontoblast staining for Nav1.1- and Nav1.5-IR increased in crown with age but decreased in roots. Nav1.9-IR was especially intense in regularly scattered odontoblasts. Two tetrodotoxin-resistant isoforms (Nav1.5, Nav1.8) had strong expression in odontoblasts near dentinal innervation zones. Nav1.6-IR was concentrated at intercusp and cervical odontoblasts in adults as was TRPA1-IR. Nav1.3-IR gradually became intense in all odontoblasts during development except where dentinal innervation was dense.

Conclusions: All nine voltage-gated sodium channels could be expressed by odontoblasts, depending on intradental location and tooth maturity. Our data reveal much greater complexity and niche-specific specialization for odontoblasts than previously demonstrated, with implications for tooth sensitivity.

Publication types

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

MeSH terms

  • Age Factors
  • Aging / genetics
  • Animals
  • Dental Pulp / cytology
  • Dental Pulp / metabolism*
  • Dentin / metabolism*
  • Fluorescent Antibody Technique
  • Incisor / cytology
  • Incisor / growth & development
  • Incisor / metabolism
  • Intermediate Filament Proteins / biosynthesis
  • Ion Channel Gating / genetics
  • Molar / cytology
  • Molar / growth & development
  • Molar / metabolism*
  • Nerve Tissue Proteins / biosynthesis
  • Nestin
  • Neurons / metabolism
  • Odontoblasts / metabolism*
  • Periodontium / metabolism
  • Phenotype
  • Protein Isoforms
  • Rats
  • Sodium Channels / biosynthesis*
  • Sodium Channels / genetics
  • TRPA1 Cation Channel
  • TRPC Cation Channels / biosynthesis
  • TRPC Cation Channels / genetics
  • Tetrodotoxin / pharmacology
  • Tooth Crown / cytology
  • Tooth Crown / metabolism
  • Tooth Eruption / genetics
  • Tooth Root / cytology
  • Tooth Root / metabolism

Substances

  • Intermediate Filament Proteins
  • Nerve Tissue Proteins
  • Nes protein, rat
  • Nestin
  • Protein Isoforms
  • Sodium Channels
  • TRPA1 Cation Channel
  • TRPC Cation Channels
  • Trpa1 protein, rat
  • Tetrodotoxin