Fibronectin does not enhance epidermal growth factor-mediated acceleration of corneal epithelial wound closure
H. K. Soong, T. Hassan, J. Varani, S. C. Huang and M. Brennan
Department of Ophthalmology, University of Michigan Medical School, Ann Arbor.
Concomitant use of epidermal growth factor and fibronectin for the
treatment of corneal epithelial wounds has a putative advantage of
promoting complementary aspects of wound healing: epidermal growth factor
enhances mitosis, while fibronectin increases cell-to-substrate
adhesiveness and possibly cell motility. To determine if the combination of
epidermal growth factor and fibronectin is synergistic in accelerating the
speed of corneal epithelial wound coverage, epithelial wound closure rates
were compared in serum-free rat corneal organ cultures among epidermal
growth factor alone, fibronectin alone, their combination, and drug-free
controls. Epidermal growth factor (50 to 1000 ng/mL) significantly
increased the rate of wound closure over that of the drug-free controls,
while fibronectin (50 to 100 micrograms/mL) had not significant effect.
Wound closure rates with combined epidermal growth factor and fibronectin
were no faster than with epidermal growth factor alone. The results
indicate that fibronectin does not accelerate the rate of corneal
epithelial migration when used alone or in combination with epidermal
growth factor. This may reflect that the major role of fibronectin may be
in the enhancement of cell-to-substrate adhesion and not of migration per
se.
