Caspase 3/GSDME-Mediated Corneal Epithelial Pyroptosis Promotes Dry Eye Disease.

PURPOSE: Dry eye disease (DED) is a common ocular surface inflammatory disease with a complex pathogenesis. Herein, the role and effect of gasdermin E (GSDME) in DED pathogenesis were explored.

METHODS

In vitro, flow cytometry, Cell Counting Kit-8 (CCK-8) and lactate dehydrogenase (LDH) release assays were used to determine the effects of hyperosmotic stress on pyroptosis, apoptosis, and cell viability in human corneal epithelial cells (HCECs). Quantitative PCR (qPCR) and Western blot assays were used to detect GSDME expression in HCECs and in those transfected with si-GSDMD. In vivo, GSDMD-knockout (KO) mice were used to study the role of GSDME in DED pathogenesis. The qPCR, Western blotting, and immunofluorescence were used to explore the effects of GSDME on HCEC apoptosis, pyroptosis, and the expression of related genes and proteins in GSDMD-KO mice with scopolamine-induced dry eye.

RESULTS

Pyroptosis and cell membrane rupture occurred, and caspase-3 and GSDME protein expression increased after HCECs were treated with 312 to 500 mOsm sodium chloride. GSDME gene and protein expression levels were increased in HCECs from both si-GSDMD- and GSDMD-KO mice. Although caspase-3 expression was increased in the dry eye group of GSDMD-KO mice, HCEC apoptosis and the apoptosis-related factors PARP were not detected. The gene and protein expression levels of the pyroptosis-related factors ASC and IL-1β were greater than those in GSDMD-KO mice without dry eye.

CONCLUSIONS

GSDME is involved in DED pathogenesis by mediating inflammation via the pyroptosis pathway, GSDME inhibition may be a therapeutic target for DED.