Trefoil peptides promote restitution of wounded corneal epithelial cells

The ocular surface shares many characteristics with mucosal surfaces. In bo th, healing is regulated by peptide growth factors, cytokines, and extracel lular matrix proteins. However, these factors are not sufficient to ensure most rapid healing. Trefoil peptides are abundantly expressed epithelial ce ll products which exert protective effects and are key regulators of gastro intestinal epithelial restitution, the critical early phase of cell migrati on after mucosal injury, To assess the role of trefoil peptides in corneal epithelial wound healing, the effects of intestinal trefoil factor (ITF/ TF F3) and spasmolytic polypeptide (SP/TFF2) on migration and proliferation of corneal epithelial cells were analyzed. Both ITF and SP enhanced restituti on of primary rabbit corneal epithelial cells in vitro. While the restituti on-enhancing effects of TGF-alpha and TGF-beta were both inhibited by neutr alizing anti-TGF-beta -antibodies, trefoil peptide stimulation of restituti on was not. Neither trefoil peptide significantly affected proliferation of primary corneal epithelial cells. ITF but not SP or pS2 mRNA was present i n rabbit corneal and conjunctival tissues. In summary, the data indicate an unanticipated role of trefoil peptides in healing of ocular surface and de mand rating their functional actions beyond the gastrointestinal tract. (C) 2001 Academic Press.