Biochemical and functional characterization of intercellular adhesion and gap junctions in fibroblasts

Am J Physiol Cell Physiol. 2000 Jul;279(1):C147-57. doi: 10.1152/ajpcell.2000.279.1.C147.


Despite their significance in wound healing, little is known about the molecular determinants of cell-to-cell adhesion and gap junctional communication in fibroblasts. We characterized intercellular adherens junctions and gap junctions in human gingival fibroblasts (HGFs) using a novel model. Calcein-labeled donor cells in suspension were added onto an established, Texas red dextran (10 kDa)-labeled acceptor cell monolayer. Cell-to-cell adhesion required Ca(2+) and was >30-fold stronger than cell-to-fibronectin adhesion at 15 min. Electron micrographs showed rapid formation of adherens junction-like structures at approximately 15 min that matured by approximately 2-3 h; distinct gap junctional complexes were evident by approximately 3 h. Immunoblotting showed that HGF expressed beta-catenin and that cadherins and connexin43 were recruited to the Triton-insoluble cytoskeletal fraction in confluent cultures. Confocal microscopy localized the same molecules to intercellular contacts of acceptor and donor cells. There was extensive calcein dye transfer in a cohort of Texas red dextran-labeled cells, but this was almost completely abolished by the gap junction inhibitor beta-glycyrrhetinic acid and the connexin43 mimetic peptide GAP 27. This donor-acceptor cell model allows large numbers (>10(5)) of cells to form synchronous cell-to-cell contacts, thereby enabling the simultaneous functional and molecular studies of adherens junctions and gap junctions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cadherins / metabolism
  • Cell Adhesion / physiology
  • Cell Communication / physiology
  • Cells, Cultured
  • Connexin 43 / metabolism
  • Cytoskeletal Proteins / metabolism
  • Fibroblasts / metabolism
  • Fibroblasts / physiology*
  • Fibroblasts / ultrastructure
  • Gap Junctions / metabolism
  • Gap Junctions / physiology*
  • Gingiva / cytology
  • Humans
  • Kinetics
  • Tissue Distribution
  • Trans-Activators*
  • beta Catenin


  • CTNNB1 protein, human
  • Cadherins
  • Connexin 43
  • Cytoskeletal Proteins
  • Trans-Activators
  • beta Catenin