Effect of protein kinase C inhibitors and activators on corneal re-epithelialization in the rat.
OBJECTIVE
To examine the ability of protein kinase C (PKC) inhibitors and activators to influence the rate of corneal re-epithelialization in the rat.


METHODS
Rat corneas with 3 mm diameter central epithelial abrasions were organ-cultured in control medium or in medium with inhibitors or activators of PKC.


RESULTS
In control corneas, the defect was completely re-epithelialized by 25 hr. In the presence of the PKC inhibitors staurosporine (100 nM), sphinganine (50 mumol/l), or H-7 (100 mumol/l) there were significantly larger epithelial defects than in controls after 5-25 hr of incubation. Re-epithelialization rates were similar to control corneas when the incubation medium contained HA1004 (100 mumol/l), an analogue of H-7 that is a potent inhibitor of cyclic adenosine monophosphate- and cyclic guanosine monophosphate-dependent protein kinases and a weak inhibitor of PKC. Two PKC activators, 1-oleoyl-2-acetyl-sn-glycerol (OAG) and phorbol 12-myristate 13-acetate (PMA), were unable to enhance the rate of epithelial wound healing.


CONCLUSIONS
Our results suggest that PKC activity is an important factor in regulating corneal epithelial wound healing, presumably by influencing cell migration. Moreover, the results with OAG and PMA suggest that PKC is maximally activated during re-epithelialization in this organ-culture assay.
Hirakata
A
A
Department of Pathology, Duke University Medical Center, Durham, North Carolina.
Gupta
A G
AG
Proia
A D
AD
D000818:Animals; D003315:Cornea / Q000166:cytology / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D008297:Male; D009924:Organ Culture Techniques; D010713:Phosphatidylcholines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014945:Wound Healing / Q000187:drug effects
D004791:Enzyme Inhibitors; D010713:Phosphatidylcholines; D011493:Protein Kinase C; C017251:1,2-oleoylphosphatidylcholine; D013755:Tetradecanoylphorbol Acetate