Effects of hepatocyte growth factor, transforming growth factor-beta1 and epidermal growth factor on bovine corneal epithelial cells under epithelial-keratocyte interaction in reconstruction culture

Exp Eye Res. 1998 Jan;66(1):105-16. doi: 10.1006/exer.1997.0419.


In the cornea, corneal epithelial cells are in close contact with keratocytes: the epithelial cells organize thickened lamellar structure on a layer of keratocytes embedded in extracellular matrix (ECM). Thus, growth factors are expected to critically regulate corneal component cells under epithelial-keratocyte interaction. The purpose of this study is to clarify effects of hepatocyte growth factor (HGF), transforming growth factor-beta1 (TGF-beta1) or epidermal growth factor (EGF) on corneal epithelial cells under epithelial-keratocyte interaction. We examined proliferation and differentiation of the epithelial cells in a simple corneal reconstruction culture composed of an epithelial cell layer on the keratocyte-containing stromal layer, using three-dimensional collagen gel matrix culture. We observed the morphological change by phase contrast microscopy, and conducted histological and immunohistochemical examinations. The epithelial proliferation was examined by nuclear bromodeoxy-uridine (BrdU) uptake. In the reconstructed cornea under epithelial-keratocyte interaction, EGF-, TGF-beta1- and HGF-treated cells formed a thickened epithelial layer consisting of 5-6, 5-6 and 3-4 cells, respectively. In fact, both EGF and TGF-beta1 induced significantly higher intakes of nuclear BrdU of the epithelial cells than HGF. In lamellar differentiation of the epithelial cells, TGF-beta1- or HGF-treated cells formed a triple lamellar structure specific for the in vivo corneal epithelium: basal, middle and superficial layers are composed of cuboidal basal-like cells, spindle wing-like cells and flat superficial-like cells, respectively. TGF-beta1-treated cells formed a more markedly thickened epithelial layer than HGF-treated cells. In contrast, EGF formed a single lamellar structure consisting of cuboidal cells. These results suggest that those growth factors regulate proliferation and/or lamellar differentiation of corneal epithelial cells under epithelial-keratocyte interaction. The most interesting result was that TGF-beta1 promotes proliferation and lamellar differentiation of corneal epithelial cells through keratocyte-mediated stimulation.

MeSH terms

  • Animals
  • Cattle
  • Cell Division / drug effects
  • Cells, Cultured
  • Cornea / cytology
  • Cornea / drug effects*
  • Culture Media, Serum-Free
  • Epidermal Growth Factor / pharmacology*
  • Epithelial Cells / cytology
  • Epithelial Cells / drug effects
  • Hepatocyte Growth Factor / pharmacology*
  • Immunohistochemistry
  • Transforming Growth Factor beta / pharmacology*


  • Culture Media, Serum-Free
  • Transforming Growth Factor beta
  • Epidermal Growth Factor
  • Hepatocyte Growth Factor