Purpose. To investigate gap junction expression in corneal epithelium and the role of junctional communication in migration and proliferation of CECs and wound repair. Methods. We used mice in which the Cx43 gene was disrupted by homologous recombination (Reaume et d., Science 267: 1831, 1995). Eyes from newborn Cx43 KO mice and WT Httermates were fixed in 2% glutaraldehyde for light and electron microscopy, frozen in liquid N2 for light and confocal microscopy of cryosection immunofluorescence, and CECs were cultured to evaluate growth rate, response to wounding, and gap junction channel permeability (Pj) and electrophysiological properties. Pj was measured using Lucifer Yellow injection or scrape loading of confluent monolayers; junctional conductance (gj) was studied by dual voltage clamp in cell pairs. Rcjpljs, In WT animals, Cx43 was primarily at lateral regions of CECs but also within the stroma. Whereas staining was positive for Cx46 and negative for Cx45 and N-Cadherin in lens epithelia, cornea in both WT and Cx43 KO mice were positive for Cx45 and N-Cadherin and negative for Cx46. Epithelial cells and keratocytes in the cornea were connected by typical gap junctional contacts; contact areas were similar in WT and Cx43 KO mice. In contrast to dramatic morphological alterations of the Cx43 KO lens, morphology of the Cx43 KO cornea was normal. WT CECs grew slightly slower than Cx43 KO, but migration after wounding was not different. Pj was extensive in WT and Cx43 KO CECs; gj was somewhat lower in Cx43 KO CECs than in WT. Junctional channels in WT CECs were primarily Cx43-like; channels in Cx43 were smaller and more voltage sensitive. Conclusions, Cx43 is not the only gap junction protein providing junctional communication in cornea. Presence of other connexin(s) presumably accounts for normal histology and wound repair in CECs.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - 1997|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience