HIF-1α Promotes Inflammatory Responses in Aspergillus Fumigatus Keratitis by Activating Pyroptosis Through Caspase-8/GSDMD Pathway.

Purpose: This research was designed to explore the expression patterns and functional significance of hypoxia-inducible factor-1α (HIF-1α) in the inflammatory response associated with Aspergillus fumigatus (A. fumigatus) keratitis.

Methods: Mouse models of A. fumigatus keratitis were created by scraping the corneal epithelium and applying A. fumigatus on the corneal surface. In the in vitro experiments, human corneal epithelial cells (HCECs) and THP-1 macrophages stimulated by A. fumigatus were used to investigate the cellular responses. HIF-1α was inhibited using LW6. Western blot, immunofluorescence, and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were performed to assess the expression levels of HIF-1α in A. fumigatus keratitis. The inflammatory response was evaluated using clinical scoring, corneal thickness measurements, hematoxylin and eosin (H&E) staining, corneal fluorescein sodium staining, and a cell scratch test. The polarization of macrophages was determined using flow cytometry. The molecular mechanisms of HIF-1α were assessed by qRT-PCR and Western blot.

Results: In A. fumigatus keratitis, the expression of HIF-1α was significantly increased at both the mRNA and protein levels. Compared with the controls, HIF-1α inhibitor accelerated corneal epithelial repair, reduced the infiltration of macrophages, induced shift in macrophage polarization, and attenuated the inflammatory response. HIF-1α exerts a pro-inflammatory effect in A. fumigatus keratitis by modulating the expression of inflammatory mediators and engaging in pyroptosis via the caspase-8/GSDMD signaling pathway.

Conclusions: In conclusion, HIF-1α promotes A. fumigatus keratitis by inhibiting corneal epithelial repair and promoting inflammation, leading to increased severity of the disease.