Systems analysis of stromal-epithelial crosstalk identifies the FGF21-FGFR3 axis as a critical driver of corneal wound healing
Purpose: Corneal epithelial defects is a significant clinical problem and poses a severe threat to vision. However, its underlying mechanism is remains largely elusive. Here, we employed single-cell RNA sequencing (scRNA-seq) and constructed cell-cell communication networks between the corneal stromal cells (CSCs) and epithelial cells (CEpCs), aiming to elucidate the pathological mechanism underlying corneal epithelial wound repair.Methods: Corneal tissues from normal and corneal epithelium defect mice were subjected to scRNA-seq. Comprehensive bioinformatic analysis, including unsupervised clustering, differential gene expression, functional enrichment, pseudotime and RNA velocity analysis, were conducted to illustrated the heterogenic of CSCs. CellChat were utilized to identify the signaling crosstalk between CEpCs and CSCs. Furthermore, silt-lamp examination, western blotting, immunofluorescence were performed to determine the FGF21-FGFR3 axis between these two cell populations. To investigate the potential molecular mechanism underlying the action of FGF21 on CEpCs via bulk RNA-sequencing analysis.Results: Unbiased clustering of scRNA-seq transcriptomes identified eight distinct CSC subpopulations. Cell-cell communication mapping and immunofluorescence validation revealed that CSCs actively engaged with CEpCs via the FGF21-FGFR3 axis. Functional experiments further demonstrated that knockdown of Fgf21 significantly delayed corneal wound healing, whereas the topical administration of FGF21 eye drops promoted corneal epithelial wound repair in vivo. Bulk RNA-seq analysis further revealed that FGF21 stimulation enhances the capacity of CEpCs to repair injury.Conclusions: Our study uncovers a novel interaction between CSCs and CEpCs mediated by FGF21-FGFR3 axis. Exogenous FGF21 prompts the wound healing of CEpCs, offering a promising novel therapeutic strategy for corneal epithelial repair.