UCLA

PURPOSE: Diabetes mellitus (DM) disrupts epithelial integrity, sensory function, basement membrane composition, wound healing, and stem cell function. Corneal epithelial homeostasis and wound healing involve the complex coordination of various sub-populations of limbal cells. However, the transcriptomic changes at the single-cell level in these cell populations associated with diabetes have never been addressed. This study aims to generate a high-resolution single-cell transcriptomic atlas of human DM corneal limbal tissue to advance our conceptual understanding of human diabetes-associated changes in cell types and composition, transcriptional states, cellular trajectories, and intercellular communication. METHODS: Single-cell sequencing (scRNA-seq) was performed on isolated corneolimbal epithelial tissues from a total of six age-matched human donors, including three non-diabetic (N) and three DM donors using 10X Genomics. Selected transcriptomic findings were assessed at the protein level by immunofluorescence staining of corneal sections. RESULTS: Thirteen distinct cell clusters were identified based on the top expressed gene markers in both N and DM samples. Analyses of differentially expressed genes (DEGs), biological pathways, pseudotime trajectories, and subclustering identified DM-associated transcriptional changes, cell-cycle differences, and altered inferred intercellular signaling patterns. Pathway analysis highlighted extracellular matrix organization, adhesion, inflammation, and ligand-receptor interactions that may be associated with diabetes-impaired corneal homeostasis. Immunofluorescence showed corresponding differences in protein staining patterns for selected markers, including decreased IFITM3, MMP-1, periostin, LGI4, and eNOS, and increased ADAMTS-4. CONCLUSIONS: We provide the first high-resolution single-cell transcriptome atlas of DM-associated alterations in the human corneolimbal niche and identify molecular pathways and cellular populations that may contribute to compromised corneal homeostasis and regenerative capacity in DM.