Reassembly of the anchoring structures of the corneal epithelium during wound repair in the rabbit.

Reappearance of the structures involved in adhesion of the corneal epithelium to the stroma was studied in healing 7 mm keratectomy wounds in rabbit corneas. Corneas were taken at 48 and 66 hr, 1, 2, 3, 4, 6 and 8 weeks, and 4, 6 and 12 months post-wounding. Immunolocalization of bullous pemphigoid antigen (BPA), laminin and type VII collagen was used to determine time and sequence of appearance of hemidesmosomes, basement membrane and anchoring fibrils, respectively. Electron micrographs from three regions in the wound were used to correlate the immunohistochemical data and to quantitate the increase in basal cell membrane occupied by hemidesmosomes and the increase in basement membrane over healing time. Evidence of resynthesis of the adhesion structures was present at the wound margin before epithelial wound closure (48 hr). BPA, laminin and type VII collagen co-localized, indicating that hemidesmosomes, basement membrane and anchoring fibrils reappeared synchronously. Reappearance of the structures proceeded from wound margin to the center, and by 1 week BPA, laminin, and type VII collagen were present in discontinuous segments across the wound. From 2 weeks to 6 months, the segments became more continuous, and anchoring fibril networks were discerned at 4 weeks. Strata of type VII collagen and laminin were present within the newly synthesized stromal matrix at wound margin at 1 week, continuous across the wound bed by 2-4 weeks, and still present at 6 months; however, at 12 months, only a few strata of type VII collagen were present below the basement membrane at wound center.(ABSTRACT TRUNCATED AT 250 WORDS)