Purpose. To examine the effect of a) exogenous growth factors, b) human corneal epithelial and keratocyte conditioned medium and c) exogenous growth factors in the presence of conditioned media on human corneal epithelial cell and keratocyte proliferation. The identity of growth factors in conditioned media was partially characterised. Methods. Preconfluent cultures of human corneal epithelial cells or stromal keratocytes were exposed to a) varying concentrations of EGF, TGF-β or bFGF, b) human corneal epithelial or stromal keratocyte conditioned medium or c) EGF, TGF-β or bFGF in the presence of conditioned medium. Cell numbers were determined after 48 hours incubation. RIA and ELISA were used to quantify the levels of EGF, TGF-β, bFGF and IGF-I in conditioned media. Results. EGF and bFGF increased, while TGF-β decreased, the proliferation of both cell types in a dose dependent manner. Epithelial cell conditioned medium inhibited, and keratocyte conditioned medium stimulated, the proliferation of both cell types. The proliferative effects of EGF, TGF-β, bFGF in the presence of keratocyte conditioned medium were additive for both cell types. By contrast, the addition of exogenous growth factors was unable to overcome the inhibitory potential of epithelial conditioned medium. Both conditioned media contained significant levels of bFGF, but TGF-β levels in epithelial conditioned medium were 5X that in keratocyte conditioned medium. Conclusions. The results indicate that corneal cells maintain tissue homeostasis and modulate the wound healing response via paracrine/autocrine pathways.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience