Promotion of corneal epithelial wound healing in vitro and in vivo by annexin A5.
OBJECTIVE
To investigate the effect of annexin A5, a calcium-dependent phospholipid-binding protein, on corneal epithelial wound healing.


METHODS
The effect of annexin A5 on migration of rabbit corneal epithelial (RCE) cells in vitro was examined in scrape-wounded cell monolayers. The effect of annexin A5 on the release of urokinase-type plasminogen activator (uPA) from cultured RCE cells was determined by zymography, fluorogenic assay of PA activity, and enzyme-linked immunosorbent assay. The proliferation of RCE cells was assessed by measurement of [3H]thymidine incorporation. The effect of annexin A5 on corneal wound closure in rabbits was investigated after removal of the corneal epithelium, either by exposure to iodine vapor or surgically. Eye drops containing annexin A5 were instilled into one eye and vehicle into the other. The area of the epithelial defect was measured at various times after wounding, and the healing rate was calculated by linear regression analysis.


RESULTS
Annexin A5 significantly promoted the migration of RCE cells in a wounded monolayer. However, annexin A5 had no effect on RCE cell proliferation. Annexin A5 also increased the release of uPA both from wounded RCE cell monolayers and from nonwounded semiconfluent RCE cells. In both models of corneal wound closure, the healing rate was significantly increased by instillation of eye drops containing annexin A5 compared with that apparent in the eyes that received vehicle.


CONCLUSIONS
Annexin A5 promoted corneal epithelial wound healing both in vitro and in vivo. Upregulation of uPA release from corneal epithelial cells may contribute to this effect of annexin A5.
Watanabe
Masanao
M
Tokyo New Drug Research Laboratories, Kowa Company Ltd., Tokyo, Japan. mwatanb@kowa.co.jp
Kondo
Shoichi
S
Mizuno
Ken
K
Yano
Wataru
W
Nakao
Hiroshi
H
Hattori
Yukio
Y
Kimura
Kazuhiro
K
Nishida
Teruo
T
D000818:Animals; D017304:Annexin A5 / Q000494:pharmacology*; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D019573:Epithelium, Corneal / Q000166:cytology / Q000293:injuries / Q000502:physiology*; D008297:Male; D011817:Rabbits; D015854:Up-Regulation; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology*
D017304:Annexin A5; D004791:Enzyme Inhibitors; D014568:Urokinase-Type Plasminogen Activator