Submitted on December 13, 2007
Revised on May 5, 2008
Accepted on May 15, 2008
Rho kinases (ROCKs) Regulate Corneal Epithelial Wound Healing
Jia Yin1 and Fu-Shin Yu2*
1 Wayne State University
2 Wayne State University, Kresge Eye Institute
* To whom correspondence should be addressed. E-mail: fyu{at}med.wayne.edu.
We previously showed that Rho small GTPase is required for modulating both cell migration and proliferation through cytoskeleton reorganization and focal adhesion formation in response to wounding. In the present study, we investigated the role of Rho kinases (ROCKs), major effectors of Rho GTPase, in mediating corneal epithelial wound healing. Both ROCK1 and 2 were expressed and activated in THCE cells, an SV40-immortalized human corneal epithelial cell (HCEC) line, in response to wounding, lysophosphatidic acid and heparin-binding EGF-like growth factor (HB-EGF) stimulations. ROCK inhibitor Y-27632 efficiently antagonized ROCK activities without affecting Rho activation in wounded HCECs. Y-27632 promoted basal and HB-EGF-enhanced scratch wound healing, enhanced cell migration and adhesion to matrices, while retarded HB-EGF-induced cell proliferation. E-cadherin and 
-catenin-mediated cell-cell junction and actin cytoskeleton organization were disrupted by Y-27632. Y-27632 impaired the formation and maintenance of tight junction barriers indicated by decreased trans-epithelial resistance and disrupted occludin staining. We conclude that ROCK activities enhance cell proliferation, promote epithelial differentiation, but negatively modulate cell migration and cell adhesion, therefore play a role in regulating corneal epithelial wound healing.
