Use of transgenic mice for in-vivo monitoring of corneal pathologies following chemical insult

Abstract

Purpose : The dynamic course of sulfur mustard (SM) induced ocular insult is characterized by an acute phase, which may be continued to a chronic phase or a quiescent period followed by a late pathology. Visually observing corneal morphological changes in living animals could greatly enhance our understanding of additional aspects of the insult and assist in developing treatments.

Methods : Chemical SM burn was induced in the right eyes of three transgenic mice strains: K15-GFP, VE-Cad-RFP and Thy1-YFP, by vapor exposure. General evaluation, cell infiltration, neovascularization (NV), innervation loss and stem cells (SC) depletion in the cornea were monitored in-vivo by stereomicroscopy up-to 8 weeks. Corneal whole-mount preparations were used to identify 360° structures, infiltrating cells and the decrease in the sub-basal nerve plexus (SNP). Histological evaluation was determined by using H&E, Masson-Trichrome and Periodic acid-Schiff staining.

Results : A 35 seconds exposure induced a mild ocular surface insult with minor mid stromal nerve fiber (MSNF) insult, moderate SNP changes presenting cell infiltration and reversible SC loss, mostly resolving at 4w post exposure. A 120 seconds exposure induced a moderate-severe ocular surface insult involving NV, with extensive MSNF and SNP loss, a wide CD45⁺, Iba1⁺ cell infiltration and irreversible SC depletion. NV, stromal inflammation and edema, epithelial structural changes and conjunctival goblet cells were identified in corneal histological sections, in correlation with the fluorescent stereoscope findings.

Conclusions : The results in this study demonstrate the potential use of transgenic
mice as a powerful animal model for studying the SM induced insult and developing new therapies.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.