Wounding of the corneal epithelium results in marked down-regulation of connexin expression at the wound site and distally

Purpose. Cell-to-cell communications have been implicated in wound healing modulation. Accordingly, we sought to examine connexin expression in the corneal epithelium during healing. Methods. Eight to 10mm long epithelial debridements of varying width were made in the central cornea of adult albino rabbits under local anesthesia. Eighteen hr later rabbits were sacrificed and the distribution to connexin 43 was examined by immunohistology in cryostat sections. Results. In the uninjured control cornea, connexin 43 (Cx43) appears as an intense punctuate staining throughout the lateral and apical membranes of the basal cells. A 4 mm wide wound (closure time; of ca. 30 h, based on 60 μm/h migration rate) resulted in the absence of the staining throughout the cornea. A 1 mm wound (closing time ca. 10 hr) resulted in the closure of Cx43 immunostaining up to at least 3 mm away from the wound center. At the healed-over zone intracellular diffuse staining was distinguishable. A 0.3 mm wound (closing time ca. under 4 hr) resulted in a decrease in the fine punctuate staining in the proximity of the wound. There was a marked increase in membranous Cx43 staining over the healed-over zone. Conclusions. Wounding of the corneal epithelium results in the expansive inhibition of junctional communications. After wound closure, recovery of junctional activity is initiated at and propagates outwards from the initial wound site.