Abstract
Purpose :
Histatins (Hst) are a multi-functional endogenous family of proteins with a variety of effects. These peptides have been described as anti-fungal, immunomodulatory, and epithelial trophic. Each member of this family of peptides has relative specialization, with Hst1 thought to be primarily epithelial trophic and Hst5 thought to be primarily anti-fungal. We reported the epithelial migration effects of Hst1 in human corneal epithelia, and other investigators have found that Hst1 can promote wound healing in rabbit corneal injury models. In this study we sought to determine whether Hst5 could promote corneal wound healing in a murine model.
Methods :
Corneal wounding experiments in mice were conducted in compliance with the Association for Research in Vision and Ophthalmology (ARVO) Statement for the Use of Animals in Ophthalmic and Vision Research. C57BL/6J (Jackson Laboratory, Bar Harbor, ME) mice were anesthetized with intraperitoneal injection of ketamine and xylazine. After applying two drops of topical 0.5% proparacaine, a 2.0-mm area of the central epithelium was demarcated using 2-mm disposable biopsy punch and removed by an AlgerBrush II (The Alger Company, Lago Vista, TX). Histatin-5 was applied to the cornea 3 times a day. At multiple time points the corneas were stained with fluorescein (FUL-GLO Fluorescein Sodium ophthalmic strips, Akorn, Lake forest, IL) and photographed using a Nikon FS-2 photo-slit lamp with a Nikon D200 camera (Melville, NY). At each indicated time point, remaining wound areas were measured using ImageJ software and compared with the baseline wound area for each mouse and the percentage of remaining wound area calculated for each time point.
Results :
Topical application of Hst5 significantly increased wound healing rates compared with control. Histological analysis of the wounded corneas (DAPI staining) demonstrated pathologic evidence of reductions in corneal wound size in the Hst5 treated condition compared to controls. Thus, Hst5 peptides can enhance wound healing in a well vetted model of murine corneal epithelial injury.
Conclusions :
This study demonstrates that topical application of Hst5 can promote corneal epithelial wound healing in a murine model. Given the broad anti-microbial and other salutary effects of histatin peptides, this study supports future work on developing histatin peptides as potential novel ophthalmic therapeutics.
This is a 2020 ARVO Annual Meeting abstract.