The influence of stromal contraction in a wound model system on corneal epithelial stratification

PURPOSE. The healing process of some corneal wounds involves closure by str omal contraction and the renewal of the stratified epithelium. In wound gap e injury such stromal contraction occurs with epithelial stratification. In previous in vitro studies of noncontracted and contracted corneal fibrobla st-seeded collagen gels (FSCGs) it was shown that initiation of wound contr action by the myofibroblast phenotype (present within the wounded stroma) w as dependent on vitronectin and/or fibronectin. This study considers one as pect of the epithelial-stromal interaction that occurs during wounding. The stratification of corneal epithelial cells on noncontracted and contracted corneal FSCGs was compared. METHODS. Dissociated bovine corneal epithelial cells were seeded on noncont racted and contracted corneal FSCGs, and these assemblies were cultured for 7 days. The epithelium that formed was evaluated using laser confocal micr oscopy and immunohistochemical markers directed against cytokeratin 3, desm oplakin I and II, integrin ord subunit, laminin, and collagen VII. The char acteristics of the epithelium were compared with stromal carriers comprised of dissociated bovine corneal epithelial cells seeded on intact stroma and basement membrane (stromal carrier biopsies). RESULTS. The stratified epithelium that developed on contracted corneal fib roblast-seeded collagen gels was similar to that formed on stromal carriers , whereas nonstratified epithelium formed on noncontracted FSCGs. CONCLUSIONS. These studies showed that the contracted state of fibroblast-s eeded gels enhanced the development of a well-organized, stratified corneal epithelium.