Effect of EGF-induced HDAC6 activation on corneal epithelial wound healing.
OBJECTIVE
Epidermal growth factor (EGF) stimulates migration in corneal epithelial wound healing. The purpose of this study was to investigate the effect of EGF-induced alpha-tubulin deacetylation through activating HDAC6 on migration in corneal epithelial wound healing.


METHODS
Human corneal epithelial (HCE) cells were cultured in DMEM/F12 medium containing 10% FBS in a 37 degrees C incubator supplied with 5% CO(2). Western blot analysis was used to determine protein expression. Activity of HDAC6 was suppressed by trichostatin A (TSA) and by siRNA specific to HDAC6. Corneal epithelial cell migration was measured by using scratch-induced directional migration assay in cultured cells and by corneal epithelial debridement using a mouse whole-eye organ culture model.


RESULTS
The authors found EGF stimulated corneal epithelial cell migration in wound healing by enhancing HDAC6 activity, resulting in the deacetylation of alpha-tubulin. EGF stimulated HDAC6 enzymatic activity and protein translocation toward the leading edge of the cell. Inhibition of HDAC6 activity by TSA significantly suppressed EGF-induced cell migration and delayed EGF-induced wound healing in epithelially debrided mouse corneas. In the meantime, knockdown of HDAC6 mRNA with specific siRNA effectively abolished EGF-induced deacetylation of alpha-tubulin, resulting in the inhibition of cell migration.


CONCLUSIONS
These results reveal an important mechanism that involves EGF-induced HDAC6 activation and alpha-tubulin deacetylation, subsequently affecting corneal epithelial migration in the wound-healing process.
Wang
Jie
J
Division of Molecular Medicine, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Torrance, California 90502, USA.
Lin
Andrew
A
Lu
Luo
L
D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D004789:Enzyme Activation; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D019573:Epithelium, Corneal / Q000187:drug effects* / Q000201:enzymology; D000073864:Histone Deacetylase 6; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D009924:Organ Culture Techniques; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D014404:Tubulin / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects*
D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014404:Tubulin; C012589:trichostatin A; D004815:Epidermal Growth Factor; C433811:HDAC6 protein, human; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases