Abstract
Purpose :
To investigate the therapeutic effect topical glycine-thymosine beta 4 (Gly-Tb4) eye drop in a mouse model of experimental dry eye (EDE).
Methods :
Eye drops consisting of 0.05% cyclosporine A (CsA),0.1% Gly-Tb4, 0.1% wild-Tb4, or balanced salt solution (BSS) were applied for the treatment of EDE. Tear volume, tear film break-up time (TBUT), and corneal staining scores were measured 7 and 14 days after treatment. At day 14, levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α and interferon(IFN)-γ were measured in the conjunctiva using a multiplex immunobead assay. Furthermore, flow cytometry, terminal deoxynucleotidyl transferase-mediated dUTP Nick-nick end labeling (TUNEL) staining, and periodic acid-Schiff (PAS) staining were performed at 14 days.
Results :
The groups treated with 0.05% CsA and 0.1% Gly-Tb4 showed a significant improvement in tear volume and TBUT compared to the EDE and BSS groups at 7 and 14 days. Corneal staining scores significantly decreased in the 0.05% CsA, 0.1%, Gly-Tb4 0.1% and wild-Tb4 groups when compared to EDE and BSS groups at days 7 and 14. In addition, in the 0.05% CsA, 0.1%, Gly-Tb4 0.1% and wild-Tb4 groups, IL-1β, IL-6, TNF-α and IFN-γ levels, percentage of CD4+CCR5+Tcells and TUNEL positive cells were lower than in EDE and BSS groups. Compared to the EDE and BSS groups, the 0.05% CsA, 0.1%, Gly-Tb4 0.1% and wild-Tb4 groups showed a higher goblet cell density (p < 0.05).
Conclusions :
Topical application of 0.1% Gly-Tb4 can markedly improve clinical signs and decrease inflammation in the ocular surface of EDE, suggesting that 0.1% Gly-TB4 eye drops may be used as a therapeutic agent for dry eye disease.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.