TYPE-IV COLLAGEN, LAMININ, AND FIBRONECTIN PROMOTE THE ADHESION AND MIGRATION OF RABBIT LENS EPITHELIAL-CELLS IN-VITRO

Purpose. To assess the ability of basement membrane and extracellular matrix proteins to promote rabbit lens epithelial cell adhesion and mi gration, which may play a role in the development of secondary catarac t. Methods. Rabbit lens epithelial cells were isolated and grown in ti ssue culture for use in standardized assays to study adhesion and migr ation of rabbit lens epithelial cells in response to type IV collagen, laminin, fibronectin, and ovalbumin. Results. Under these conditions, the adhesion of rabbit lens epithelial cells to surfaces coated with varying concentrations of type IV collagen, laminin, and fibronectin w as shown to be dependent on concentration. Rabbit lens epithelial cell s did not adhere to ovalbumin-coated surfaces at any concentration tes ted. Type IV collagen promotes maximal in vitro adhesion of rabbit len s epithelial cells at lower coating concentrations in comparison to la minin and fibronectin. In cell migration experiments, fibronectin prom oted maximal migration at lower concentrations in comparison with lami nin and type IV collagen. This was shown both in haptotaxis experiment s (the migration of cells to surfaces coated with protein) and in chem otaxis experiments (the migration of cells to attractants in solution) . Lens epithelial cells did not migrate in response to ovalbumin under the conditions of this study. Conclusion. The results of these studie s indicate that adhesion and migration of lens epithelial cells occurs in response to the lens capsule proteins type IV collagen and laminin and in response to fibronectin, a protein found in the lens during em bryologic development. Because fibronectin plays a role in the embryol ogic development of the lens but is not normally present in the adult lens, the possible introduction of fibronectin into the eye after surg ery may play a critical role in the posterior migration of lens epithe lial cells and the development of posterior capsular opacification or secondary cataract.