Development of an in vitro model of galactose-induced keratoepitheliopathy using a corneal epithelial cell line

Purpose. To develop an in vitro model of galactose-induced kerato-epitheliopathy to study diabetic complications of corneal epithelium. Methods. Immortalized rabbit corneal epithelial cells developed by transfecting primary cultures with a simian virus 40 (SV40) large T antigen DNA were exposed to galactose and analyzed for accumulation of polyol, plating efficiencies and mitotic rate. As controls, the cells were cultured in the same medium containing glucose in place of galactose. Results. Immunoblotting analysis showed that a 38kD protein in the immortalized cells as well as normal corneal epithelial cells reacted with the antibody against aldose reductase (AR). A significant accumulation of galactitol was detected in the cells after exposed to galactose and not detectable in controls. Plating efficiencies of the cells exposed to galactose for 6 hours were lower than those of controls (39.0+/-5.9% in Galactose group and 56.5+/-10.8% in Control group p<0.01). There were no differences in mitotic rate between the groups (34.3+/-4.0% in Galactose group and 36.0+/-2.5% in Control group p=0.27). Conclusions. Galactose had no effect on mitotic rate of the cells but did, however, reduce the plating efficiencies of the cells. The low plating efficiencies of the cells after exposure to galactose may correlate to the less adhesiveness, one of the contributing factors to slower wound healing and increased epithelial fragility seen in the corneas of diabetic patients. This cell line also expressed AR and accumulated galactitol after exposed to galactose, which suggests that exposure to galactose may induce AR mediated dysfunctions in corneal epithelial cells.