Abstract
Purpose :
The aim of this study was to evaluate interleukin-6 (IL-6) expression in an ex vivo model of equine corneal wound healing.
Methods :
Equine corneas (n=14) were harvested within two hours of humane euthanasia for reasons unrelated to the study. Corneas were randomly assigned to wounded (n=8) or unwounded (n=6) controls. Corneoscleral rims were excised 2mm posterior to the limbus. The axial cornea was wounded by applying a 6mm filter paper disk soaked in 1N-NaOH for 60 seconds. Corneas were cultured using an air-liquid interface model. The rocker was set to bathe the cornea 8 times per minute. The size of the corneal ulcers was measured daily. Corneas were submitted for histologic evaluation and RNAscope in situ hybridization for evaluation of IL-6 expression at predetermined time points of 24, 48 and 72 hours. Interleukin-6 expression was scored per RNAscope manufacturer guidelines.
Results :
All corneal ulcers healed within 72 hours while maintaining normal architecture and minimal stromal edema. The average IL-6 expression score for wounded corneas was 1.7, 0.93, and 0.2 for T24, T48, and T72 respectively. The basal epithelial layer expressed the greatest amount of IL-6 closest to the wound margin. The average score for unwounded corneas was 0.3 for T24, and 0 for T48 and T72.
Conclusions :
Interleukin-6 expression increases in wounded equine corneas compared to unwounded ones. The greatest IL-6 expression is in the basal epithelial layer, close to the wound margin. As the corneal wound healing progresses, IL-6 expression decreases.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.