Low levels of hydrogen peroxide stimulate corneal epithelial cell adhesion, migration, and wound healing

Intracellular reactive oxygen species have been reported to associate with growth factor and integrin signalings in promoting cell adhesion in many cell types. This study is to explore if exogenous H(2)O(2) at low levels can be beneficial to cell adhesion, migration, and wound healing.

Primary rabbit corneal epithelial cells treated with 0-70 μM H(2)O(2) were tested for viability by MTT assay, adhesion by centrifugation assay, focal contacts of vinculin and F-actin by immunofluorescence, activated Src(pY416), EGF receptor (pY845), vinculin(pY1065), FAK(pY397), and FAK(pY576) by immunoblotting. Cell migration was examined with 0-50 μM H(2)O(2) using the scratch wound technique. Corneal wound healing of ex vivo pig model and in vivo mouse model was examined using H(2)O(2) with and without antioxidant N-acetylcysteine (NAC).

Compared with the untreated control, H(2)O(2) at 10-50 μM stimulated cell viability and facilitated adhesion and migration with clear induction of vinculin-rich focal adhesions and F-actin-containing stress fibers by increasing activated Src, FAK(pY576), and vinculin(pY1065). H(2)O(2) also increased phosphorylation of EGFR(Y845) parallel to that of activated Src, but both were eliminated by NAC and PP1 (Src inhibitor). Finally, H(2)O(2) induced faster wound healing in cornea both in vitro and in vivo, but the healing was diminished by NAC.

These findings suggest that H(2)O(2) at low levels promotes cell adhesion, migration, and wound healing in cornea cells or tissue, and the interaction of H(2)O(2) with Src plays a major role.