Healing Ability of Central Corneal Epithelium in Rabbit Ocular Surface Injury Models

PURPOSE: Wound healing of the corneal epithelium mainly involves two types of cells: limbal stem/progenitor cells (LSCs) and differentiated central corneal epithelial cells (CECs). The healing ability of CECs is still debatable, and its correlated transcriptomic alterations during wound healing are yet to be elucidated. This study aimed to determine the healing ability and mechanisms underlying the actions of CECs using rabbit ocular surface injury models. METHODS: A central corneal ring-like residual epithelium model was used to investigate the healing ability of CECs. Uninjured and injury-stimulated LSCs and CECs were collected for transcriptomic analysis. The analysis results were verified by quantitative reverse transcriptase polymerase chain reaction, immunofluorescence staining, and two types of rabbit corneal injury models. RESULTS: During wound healing, the upregulated genes in LSCs were mostly enriched in the mitotic cell cycle–related processes, but those in CECs were mostly enriched in cell adhesion and migration. CECs could repair the epithelial defects successfully at one-time injuries. However, after repetitive injuries, the CECs repaired notably slower and failed to completely heal the defect, but the LSCs repaired even faster than the one-time injury. CONCLUSIONS: Our results indicated rabbit CECs repair the epithelial defect mainly depending on migration and its proliferative ability is limited, and LSCs are the main source of regenerative epithelial cells. TRANSLATIONAL RELEVANCE: This study provides information on gene expression in the corneal epithelium during wound healing, indicating that regulation of the cell cycle, cell adhesion, and migration may be the basis for future treatment strategies for corneal wound healing.