Quantitative analysis of the effects of extracellular matrix proteins on membrane dynamics associated with corneal epithelial cell motility

Abstract

Purpose: Interaction of corneal epithelial cells with components of the basement membrane regulates cell morphology, adhesion, and migration. The authors examined the effects of basement membrane components on the behavior of human corneal epithelial (HCE) cells, including movement of the cell membrane in relation to the direction of cell migration.

Methods: HCE cells were plated on fibronectin, laminin, collagen types I and IV, and bovine serum albumin (BSA). Cell adhesion was evaluated by staining with crystal violet. Cell movement was monitored by time-lapse microscopy, and an image processing program was developed for quantitative analysis of movement of the cell membrane in relation to the direction of cell migration. Actin cytoskeleton, focal adhesions, and the K+ channel Kv2.1 were detected by fluorescence microscopy.

Results: Laminin, fibronectin, and collagen types I and IV each promoted cell adhesion compared with that apparent with BSA. Fibronectin and collagen types I and IV, but not laminin, increased cell motility. Laminin had no effect on membrane movement compared with that observed in the presence of BSA. Collagen types I and IV each increased membrane movement but in a manner independent of the direction of cell migration. Fibronectin induced membrane movement in the direction of cell migration. Fibronectin induced the formation of thick bundles of F-actin and focal adhesions at the cell periphery and the localization of Kv2.1 at the leading edge of the cell, whereas laminin and collagen types I and IV elicited the formation of thinner bundles of F-actin and smaller focal adhesions.

Conclusions: Fibronectin may modulate the directional migration of corneal epithelial cells.