Selective changes in protein kinase C (PKC) isoform expression in rabbit corneal epithelium during wound healing. Inhibition of corneal epithelial repair by PKC alpha antisense
G. Chandrasekher et al., Selective changes in protein kinase C (PKC) isoform expression in rabbit corneal epithelium during wound healing. Inhibition of corneal epithelial repair by PKC alpha antisense, EXP EYE RES, 67(5), 1998, pp. 603-610
Protein kinase C (PKC) isoforms display different sensitivities to modulato
rs, tissue specificities and subcellular localizations. PKC alpha increases
during rabbit corneal epithelial wound healing. Here we report differentia
l expression of PKC isoforms in the cornea of rabbits at 1, 2, 4 and 8 days
during reepithelization. Cytosolic, membrane and detergent-insoluble fract
ions from epithelium were analysed by Western blot using monoclonal antibod
ies against the different PKC isoforms. We have identified PKCa, gamma, eps
ilon, mu and iota. PKC alpha and gamma were expressed only in the cytosolic
fraction, with the expression of PKCa markedly increasing 4 days after inj
ury. Corneas cultured in the presence of rabbit-specific PKC alpha antisens
e showed a greater than 50% inhibition of wound closure, compared to contro
ls. The PKC epsilon and mu were expressed in the soluble, as well as in the
membrane fraction. Additionally, 12% of PKC mu was found attached to the d
etergent insoluble fraction. The expression of the membrane-bound PKC epsil
on and mu isoforms decreased between 1 and 2 days following injury. Only 10
% of the PKC iota expressed in corneal epithelium was membrane bound, but b
etween 4 and 8 days after de-epithelization, the expression in this fractio
n increased three-fold. Our results suggest that changes in the expression
and distribution within the various fractions of selective isoforms of PKC
after injury could be involved in events leading to wound healing and that
PKCa is a key modulator in rabbit corneal wound repair. (C) 1998 Academic P
ress.