RIPK3/SQSTM1-Mediated Necroptosis Activates the NLRP3 Inflammasome in Dry Eye Disease.

PURPOSE: Dry eye disease (DED) is characterized by progressive corneal epithelial damage and chronic inflammation, yet the specific cell death mechanisms underlying epithelial loss remain unclear. This study investigated the role of RIPK3-mediated necroptosis in corneal epithelial injury and inflammation in DED.

METHODS

A DED murine model was established using scopolamine hydrobromide and desiccative stress. Corneal damage was assessed via fluorescein staining, SEM, and TEM. Molecular mechanisms were explored through RNA-sequencing, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis. The pathogenic role of RIPK3 and NLRP3 was validated using knockout (RIPK3-/-, NLRP3-/-), AAV-mediated overexpression, and siRNA knockdown. The therapeutic potential of the necroptosis inhibitor Necrostatin-1 was evaluated in vivo.

RESULTS

RNA-sequencing and KEGG analysis identified the TNF signaling pathway and necroptosis markers (RIPK3, MLKL) were significantly upregulated in DED corneal epithelium. RIPK3 knockdown markedly alleviated corneal epithelial damage and cell death, whereas localized RIPK3 overexpression exacerbated epithelial injury and inflammatory responses. Mechanistically, SQSTM1 act as a critical downstream mediator of RIPK3, promoting MLKL activation and necroptosis independently of canonical autophagic flux. Further analyses demonstrated that the RIPK3-SQSTM1 axis directly amplified NLRP3 inflammasome activation, thereby linking epithelial cell death to sustained inflammatory signaling. Consistently, desiccative stress induced rapid and persistent RIPK3-MLKL activation in human corneal epithelial cells, whereas Necrostatin-1 preserved corneal epithelial integrity and suppressed inflammasome activation in vivo.

CONCLUSIONS

This study identifies a RIPK3-SQSTM1-NLRP3 signaling axis as a key driver of corneal epithelial damage and inflammation in DED. These findings provide mechanistic insight into ocular surface epithelial loss and highlight necroptosis as a promising therapeutic target for DED.