Fusarium solani Activates PANoptosis and Modulates Immune Response in Fungal Keratitis

This study aimed to investigate how Fusarium solani triggers PANoptosis in fungal keratitis and to examine the toxic impacts and underlying mechanisms of deoxynivalenol (DON) on human corneal epithelial (HCE-T) cells.

A F. solani keratitis mouse model was established through intrastromal injection of fungal spores. Clinical severity was evaluated using a standardized scoring system. PANoptosis markers in corneal tissues were analyzed via western blotting, immunofluorescence, and TUNEL assay. Real-time PCR was used to quantify inflammatory cytokines. RNA sequencing was conducted to select differentially expressed genes (DEGs) and analyze immune cell infiltration profiles. HCE-T cells were exposed to DON, and PANoptosis-related proteins were detected via western blot and immunofluorescence. Gene expression alterations were analyzed using RNA sequencing.

PANoptosis activation was validated through upregulated expression of cleaved caspases-1, -3, -7, and -8; gasdermin D (GSDMD); and phosphorylated mixed lineage kinase domain-like protein (p-MLKL) in infected corneas, accompanied by augmented TUNEL-positive cells. Inflammatory cytokines (IL-6, IL-1β, TNF-α) were significantly upregulated. RNA sequencing revealed significant changes in PANoptosis, immune response, and extracellular matrix organization. Immune infiltration profiling indicated a marked increase in M1 macrophages in infected corneas. In vitro experiments demonstrated that DON exposure increased PANoptosis markers (cleaved caspases-1, -3, -7, and -8; BAX; GSDMD; and p-MLKL) in HCE-T cells, along with upregulation of inflammatory cytokines (IL-6, IL-1β, IL-18, TNF-α). RNA sequencing further revealed alterations in ribosomal RNA (rRNA) processing and extracellular matrix organization pathways in DON-treated cells.

F. solani infection and DON exposure induce PANoptosis in fungal keratitis, leading to significant inflammatory responses. These results suggest that targeting PANoptosis signaling pathways may represent a novel therapeutic approach for treating fungal keratitis.