Autologous Serum from Sjögren’s Syndrome Patients Mitigates Ferroptosis in Hyperosmolarity-Induced Corneal Epitheliopathy

<b><i>Purpose:</i></b> To investigate the role of autologous serum (AS) in alleviating hyperosmolarity-induced corneal epitheliopathy via the ferroptosis pathway. <b><i>Methods:</i></b> AS was extracted and prepared from patients with Sjögren's syndrome. An <i>in vitro</i> hyperosmotic dry eye model was established by exposing HCE-T cells to 90 mM NaCl, followed by treatment with AS or ferroptosis inhibitors. Protein expression was analyzed using Western blotting. Intracellular Fe²⁺ and reactive oxygen species (ROS) levels were determined by FerroOrange and 2',7'-Dichlorodihydrofluorescein diacetate (H2DCFDA) fluorescent probes, and cellular malondialdehyde and glutathione levels were measured using kits. Transmission electron microscopy was utilized to examine mitochondrial ultrastructure. <b><i>Results:</i></b> Under hyperosmotic conditions, HCE-T cells exhibited increased lipid peroxidation and iron accumulation, accompanied by significant alterations in the expression of ferroptosis-related markers and characteristic changes in mitochondrial morphology, which indicated the induction of ferroptosis. Among the tested concentrations, 20% and 50% AS demonstrated notable therapeutic effects, significantly enhancing cell viability and migration, reducing ROS and Fe²⁺ levels, and alleviating mitochondrial damage. Furthermore, AS effectively inhibited ferroptosis through the Xc^-/glutathione peroxidase 4 (GPX4) pathway. <b><i>Conclusions:</i></b> AS reduced lipid peroxidation levels in HCE-T cells under hyperosmolarity and inhibited ferroptosis through the Xc^-/GPX4 pathway.