Role of fibronectin in the healing of superficial keratectomies in vitro.
A fibronectin (Fn)-fibrinogen (Fg) surface matrix is not essential for epithelial cell migration in a corneal epithelial scrape wound model, in which the basement membrane is preserved. We have therefore tested whether such a provisional scaffolding becomes more critical in a superficial keratectomy model, when the basement membrane is surgically removed. Exogeneous Fn at 0.3 mg/ml was added to the medium of organ cultures of rabbit superficial keratectomies. At 48 hr after wounding, the healing rate was 1.12 +/- 0.03 mm2/hr in control corneas and 1.11 +/- 0.03 mm2/hr in those cultured with Fn. At 64 hr after wounding, the healing rates were also not significantly different (P greater than 0.5). Immunofluorescence studies showed that Fn was not detectable on the surface of control corneas but could be depicted under the migrating epithelium. In corneas cultured with Fn, it diffused throughout the entire stroma but did not deposit as a surface matrix. We therefore attempted to obtain formation of a provisional Fn-Fg surface matrix before establishment of the in vitro organ culture by leaving the superficial keratectomies in vivo for 8 hr, 24 hr or 64 hr. At 64 hr after wounding, their healing rate was 0.80 +/- 0.04 mm2/hr, 0.86 +/- 0.04 mm2/hr and 0.85 +/- 0.06 mm2/hr, respectively, which were not significantly different from that of contralateral ex vivo-wounded cultured corneas (0.83 +/- 0.04 mm2/hr, P greater than 0.5). Immunofluorescence studies revealed a Fn matrix on the bare surface of in vivo-wounded specimen, which was not detectable on ex vivo-wounded cultured corneas; there was also no diffuse stromal Fn.(ABSTRACT TRUNCATED AT 250 WORDS)
Phan
T M
TM
Department of Pathology, Massachusetts General Hospital, Boston 02114.
Foster
C S
CS
Zagachin
L M
LM
Colvin
R B
RB
D000818:Animals; D003315:Cornea / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005340:Fibrinogen / Q000502:physiology; D005353:Fibronectins / Q000494:pharmacology / Q000502:physiology*; D007150:Immunohistochemistry; D009924:Organ Culture Techniques; D011817:Rabbits; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects
D005353:Fibronectins; D005340:Fibrinogen