Single-cell RNA sequencing reveals LGALS9+ epithelial and COMP+ stromal cell crosstalk driving keratoconus pathogenesis.

OBJECTIVES

Keratoconus is an ophthalmic disease that seriously endangers patients' vision and quality of life. This study aimed to investigate the cellular landscape of keratoconus and uncover key pathological cell populations and signaling pathways contributing to disease progression.

METHODS

We integrated single-cell RNA sequencing (scRNA-seq) data on corneal tissues from five keratoconus patients and five healthy controls. Bioinformatic analyses were used to identify cell subclusters, examine intercellular communication, and explore potential disease-associated signaling pathways. Immunofluorescence and western blot were used for validation.

RESULTS

Two disease-specific cell subpopulations were identified: LGALS9-positive corneal epithelial cells and COMP-positive corneal stromal cells. These subtypes formed a pro-fibrotic and pro-inflammatory network through LGALS9-CD44/CD45 and thrombospondin signaling pathways. Notably, LGALS9-positive epithelial cells and CD44-positive, COMP-positive stromal cells appear to interact via the LGALS9-CD44, promoting extracellular matrix remodeling. Moreover, WB and immunofluorescence analyses revealed significant upregulation of LGALS9 in the corneal epithelium and COMP in the stroma of keratoconus samples compared to controls.

CONCLUSIONS

This study provides novel insights into the pathogenesis of keratoconus by identifying key pathological cell subpopulations and their interactions. These findings offer potential targets for therapeutic intervention, particularly by disrupting the pathological crosstalk between LGALS9-positive epithelial cells and COMP-positive stromal cells.