A Novel Therapeutic Approach to Corneal Alkaline Burn Model by Targeting Fidgetin-Like 2, a Microtubule Regulator

PURPOSE: The purpose of this study was to determine the efficacy of nanoparticle-encapsulated Fidgetin-like 2 (FL2) siRNA (FL2-NPsi), a novel therapeutic agent targeting the FL2 gene, for the treatment of corneal alkaline chemical injury. METHODS: Eighty 12-week-old, male Sprague-Dawley rats were divided evenly into 8 treatment groups: prednisolone, empty nanoparticles, control-NPsi (1 µM, 10 µM, and 20 µM) and FL2-NPsi (1 µM, 10 µM, and 20 µM). An alkaline burn was induced onto the cornea of each rat, which was then treated for 14 days according to group assignment. Clinical, histopathologic, and immunohistochemical analyses were conducted to assess for wound healing. FL2-NPsi-mediated knockdown of FL2 was confirmed by in vitro quantitative polymerase chain reaction (qPCR). Toxicity assays were performed to assess for apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling [TUNEL] assay) and nerve damage (whole mount immunochemical staining). Statistical analyses were performed using Student's t-test and ANOVA. RESULTS: Compared with controls, FL2-NPsi-treated groups demonstrated enhanced corneal wound healing, with the 10 and 20 µM FL2-NPsi-treated groups demonstrating maximum rates of corneal re-epithelialization as assessed by ImageJ software, enhanced corneal transparency, and improved stromal organization on histology. Immunohistochemical analysis of vascular endothelial cells, macrophages, and neutrophils did not show significant differences between treatment groups. FL2-NPsi was not found to be toxic to nerves or induce apoptosis (p = 0.917). CONCLUSIONS: Dose-response studies found both 10 and 20 µM FL2-NPsi to be efficacious in this rat model. FL2-NPsi may offer a novel treatment for corneal alkaline chemical injuries. TRANSLATIONAL RELEVANCE: Basic cell biology findings about the microtubule cytoskeleton were used to design a therapeutic to enhance corneal cell migration, highlighting the promise of targeting microtubules to regulate corneal wound healing.