Single-cell RNA sequencing of mouse cornea during wound healing after infrared laser irradiation

The cornea is highly specialized and a detailed map of the diverse component cell types is a vital tool for ocular disease treatment and corneal healing. Single-cell RNA sequencing (scRNA-seq) was performed to analyze corneal wound healing in C57BL/6J mice following 3.74 μm infrared laser injury (23.2 J/cm²). Analysis of 12,956 cells from 10 healthy corneas identified 28 clusters of epithelial stem cells, differentiated epithelial cells, stromal cells, endothelial cells, immune cells, Schwann cells and progenitor populations. Three newly differentiated epithelial subpopulations emerged at 3 days post-injury and a marked increase in immune cells, especially neutrophils and CD163+ macrophages, was seen. Differentiated epithelial cells and normal stromal cells decreased, myofibroblasts and stromal stem cells increased and endothelial cells and Schwann cells declined. Immune cell numbers and myofibroblasts had decreased by 21 days post-injury and differentiated epithelial cells, normal stromal cells and stromal stem cells had increased. Endothelial cells and Schwann cells showed partial recovery. Corneal repair was composed of two distinct phases. An early inflammatory phase was characterized by immune activation and epithelial remodeling and a late recovery phase by stromal restoration, myofibroblast regression and neural/endothelial regeneration. Dynamic cellular interactions during corneal wound healing are described by the present work.