Fibronectin and corneal epithelial wound healing in the vitamin A-deficient rat
G. T. Frangieh, K. Hayashi, C. Teekhasaenee, G. Wolf, R. B. Colvin, I. K. Gipson and K. R. Kenyon
Eye Research Institute of Retina Foundation, Boston, MA.
The time course of the appearance of fibronectin (Fn) on wounded corneal
surfaces was studied in vitamin A-deficient (A-) and pair-fed control rats.
At various times following a central epithelial abrasion, the tissue was
harvested, and Fn was localized on frozen corneal sections by an indirect
immunofluorescence technique. There was no detectable Fn in intact,
nonwounded control or intact A-corneas, except for Descemet's membrane.
Within a half hour after abrasion, a band of Fn appeared on the denuded
corneal surface of pair-fed control rats and became a continuous, prominent
layer at four hours. This layer remained until 16 hours but disappeared at
24 hours when the epithelium had resurfaced over the defect. In severely A-
rats, reepithelialization following central epithelial abrasion was
delayed, and no Fn band was discernible at any time from one to 32 hours
after injury. Light microscopy revealed a progressive increase in
polymorphonuclear neutrophil infiltration with time in the underlying
stroma in severely A- rats. This study indicated that in severe vitamin A
deficiency, delayed epithelial migration is associated with an inflammatory
cell layer and occurred in the absence of Fn.
