Promotion of Corneal Epithelial Wound Healing in Diabetic Rats by the Fibronectin-Derived Peptide PHSRN.

Abstract

Topical application of the fibronectin-derived peptide PHSRN facilitates corneal epithelial wound healing in healthy animals and in patients with nonhealing epithelial defects. We have now examined the effect of PHSRN eye drops on the healing of corneal epithelial wounds in diabetic rats. Wistar rats were injected intraperitoneally with streptozotocin to induce diabetes or with a vehicle as a control. Four weeks after confirmation of the corresponding presence or absence of glycosuria, a 3-mm-diameter portion of the corneal epithelium of the right eye was excised and eye drops containing PHSRN (200 μM) or phosphate-buffered saline (PBS) vehicle were administered to the injured eye every 6 hours. The area of the epithelial defect did not differ significantly among the 4 experimental groups (diabetic or nondiabetic rats treated with PHSRN or vehicle) at 12 hours after wounding. At 18 hours, however, the area of the defect in diabetic rats treated with PHSRN (0.50 ± 0.34 mm) was significantly (P < 0.05) smaller than that in diabetic rats treated with PBS (1.06 ± 0.42 mm) and was similar to that in nondiabetic rats treated with PBS (0.60 ± 0.23 mm). The decrease in the size of the epithelial defect in diabetic rats treated with PHSRN was also found to be dependent on the dose of the peptide. Administration of PHSRN significantly facilitated healing of corneal epithelial wounds in diabetic rats, which suggests that PHSRN eye drops warrant further investigation as a treatment option for patients with diabetic keratopathy.