Spatial transcriptomics and single-cell RNA-sequencing revealed dendritic cell-mediated inflammation in keratoconus.

Keratoconus (KC) is a corneal disorder characterized by central corneal protrusion and thinning. In this study, spatial transcriptomics was employed to investigate molecular and cellular variations in KC, revealing a distinct pattern of inflammatory responses across the cornea. Upregulation of inflammatory processes was observed in the central cornea, while downregulation was noted in the periphery, indicating complex regional inflammatory changes in the KC cornea. Integration with single-cell RNA sequencing (scRNA-seq) further identified enhanced interactions between dendritic cells (DCs) and stromal cells, particularly mediated via the IL-1β pathway, alongside increased matrix metalloproteinase (MMP) production by corneal stromal cells, underscoring the role of inflammation in KC pathogenesis. In vitro and in vivo experiments confirmed that activated DCs promoted the matrix degradation activity of stromal cells, thereby exacerbating KC pathology. Notably, inhibition of the IL-1β pathway effectively mitigated the progression of KC. These findings provide a comprehensive spatial, cellular, and molecular characterization of KC, demonstrating its inflammatory nature. The results also highlight the importance of inflammation in the peripheral cornea for early diagnosis and suggest that anti-inflammatory treatments could serve as potential adjuvant therapy for KC.