A single-cell atlas of diabetes-associated remodeling in the human corneal limbus

Abstract

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.