Differential regulation of key stages in early corneal wound healing by TGF-beta isoforms and their inhibitors.
OBJECTIVE
Inhibition of TGF-beta reduces myofibroblast differentiation and fibrosis in the cornea. Determining the actions of distinct TGF-beta isoforms and their inhibitors during early corneal wound healing is an essential step in guiding therapeutic intervention.


METHODS
Bovine serum-free corneal cell and wounded organ cultures were challenged with a range of concentrations of TGF-beta1, -beta2, and -beta3; IL-10; and neutralizing human monoclonal antibodies (mAbs) against TGF-beta1 (CAT-192) or -beta2, (CAT-152). Cultures were assessed for re-epithelialization, proliferation (cell counts and cresyl violet assay), morphology (histologic examination), repopulation of the area under the wound, and myofibroblast transformation (alpha-smooth muscle actin) between 0 and 5 days.


RESULTS
TGF-beta1 delayed re-epithelialization, increased repopulation of the stroma, increased keratocyte proliferation and was the only isoform to promote myofibroblast differentiation. The anti-TGF-beta1 mAb, CAT-192 promoted re-epithelialization and reduced repopulation of the stroma. Exogenous TGF-beta3 had little effect on re-epithelialization but reduced repopulation of the stroma. IL-10 promoted corneal re-epithelialization at low doses but inhibited this response at high doses. Stromal repopulation was prevented by all doses of IL-10. TGF-beta2 or the anti-TGF-beta2 mAb, CAT-152 had little effect on any repair parameter.


CONCLUSIONS
The results confirm TGF-beta1 as the principal isoform in corneal wound healing and suggest that inhibition of the action of TGF-beta1 can promote corneal wound healing. Treatment with the anti-TGF-beta1 mAb CAT-192 accelerates corneal re-epithelialization but reduces cell repopulation of the stroma. The cytokines TGF-beta3 and IL-10 have opposing actions to that of TGF-beta1.
Carrington
Louise M
LM
Cell and Molecular Unit, School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom.
Albon
Julie
J
Anderson
Ian
I
Kamma
Christina
C
Boulton
Mike
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002417:Cattle; D002452:Cell Count; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003315:Cornea / Q000166:cytology / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology*; D005347:Fibroblasts / Q000166:cytology*; D009924:Organ Culture Techniques; D020033:Protein Isoforms / Q000037:antagonists & inhibitors / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D014945:Wound Healing / Q000502:physiology*
D000911:Antibodies, Monoclonal; D020033:Protein Isoforms; D016212:Transforming Growth Factor beta