Corneal regenerative contribution of endogenous and grafted limbal-corneal cells in a mouse model of simple limbal-corneal epithelial transplantation

: Severe ocular damage, such as corneal alkali-injury, can compromise the limbal stem cell (LSC) niches, leading to LSC deficiency (LSCD) and resulting in significant vision impairment. Current insights into the wound healing process associated with simple limbal epithelial transplantation (SLET), a therapeutic intervention for LSCD, are derived solely from clinical studies, which impose methodological limitations and hinder a complete understanding of the cellular dynamics underlying SLET. For the first time, we adapted the clinical SLET procedure to a mouse model of LSCD, enabling a robust and detailed assessment of short- and long-term morphological, immunomodulatory and cell-fate outcomes in corneal regeneration. We demonstrated that simple limbal-corneal epithelial transplantation (SLCET) treatment effectively reduces corneal opacification, vascularization, and inflammation induced by alkali-injury, with persistent benefits. We used transgenic GFP-expressing mice to isolate GFP-positive limbal-corneal cells and trace their fate in the context of SLCET. Our results revealed that both endogenous and transplanted cells contribute to replenishing the depleted limbal-corneal cell population. Furthermore, we showed that the engrafted-cells retained a long-term proliferative capacity and stemness phenotype, underscoring their role in sustained corneal regeneration. Overall, our study provides a temporal and mechanistic overview of SLCET outcomes, highlighting the engrafted-cells as key players in corneal regeneration. This framework also holds a strong translational potential for enhancing SLET's efficacy and uncovering novel LSC modulators.