The mechanisms of cell membrane resealing in rabbit corneal epithelial cells

To examine membrane repair mechanisms in rabbit corneal epithelial (RCE) cells.

Microneedle puncture and fluorescent dye loss were used to wound membranes and assay resealing, respectively. Different repair mechanisms were detected pharmacologically and with antisense oligonucleotides.

The RCE cells rapidly reseal plasma membranes by calcium-dependent exocytotic mechanisms that exhibit both facilitated and potentiated responses to multiple wounding. The facilitated response was inhibited by specific inhibitors of protein kinase C (PKC) and brefeldin A, and the potentiated response was blocked by inhibitors of cAMP-dependent protein kinase (PKA). Reduction of myosin IIA inhibited the facilitated response, and reduction of IIB inhibited the initial resealing.

RCE cells rapidly repair plasma membrane disruptions. At a second wound at the same site, PKC stimulated vesicle formation from the Golgi apparatus, resulting in more rapid membrane resealing for a facilitated response. The RCE cell also contains a PKA-dependent global potentiation of membrane resealing.