Regulation by P2X7: epithelial migration and stromal organization in the cornea.

Purpose: Previously, the authors demonstrated that BzATP, a P2X(7) receptor agonist, enhanced corneal epithelial migration in vitro. The goal here was to characterize the role of the P2X(7) receptor in the repair of in vivo corneal epithelial debridement wounds and in the structural organization of the corneal stroma.

Methods: Epithelial debridement was performed on P2X(7) knockout (P2X(7)(-/-)) and wild-type (WT) mice, and eyes were harvested after 16 hours.

Injury and nucleotides induce phosphorylation of epidermal growth factor receptor: MMP and HB-EGF dependent pathway.

The early events that occur rapidly after injury trigger signal cascades that are essential for proper wound closure of corneal epithelial cells. We hypothesize that injury releases ATP, which stimulates purinergic receptors and elicits the phosphorylation of epidermal growth factor receptor (EGFR) tyrosine residues and subsequent cell migration by a MMP and HB-EGF dependent pathway. We demonstrated that the inhibition of purinergic receptors with the antagonist, Reactive Blue 2, abrogated the phosphorylation of EGFR and ERK.