Digoxin Attenuates Ocular Hypertension and Protects Trabecular Meshwork Cells via Ferroptosis Inhibition

Emerging evidence implicates ferroptosis in trabecular meshwork (TM) injury during glaucoma pathogenesis. This study aims to systematically characterize ferroptosis-related gene signatures in primary open-angle glaucoma (POAG) and identify small-molecule therapeutics targeting this mechanism.

We performed Mendelian randomization (MR) analysis of East Asian genome-wide association study data to assess causal relationships between blood metals and POAG. Ferroptosis-related indicators (iron ions, MDA, GPX4, GSH) were measured in aqueous humor samples from patients with POAG using ELISA. Genome-wide expression of TM from patients with POAG was integrated with ferroptosis-related gene sets (FerrDb) to identify core regulatory genes. The CMap database and molecular docking were employed to screen therapeutic compounds, with subsequent validation in hydrogen peroxide (H2O2)-induced TM ferroptosis models. Digoxin was formulated as topical ophthalmic drops and administered twice daily to chronic ocular hypertension (COH) rat models to evaluate its IOP-lowering efficacy.

MR analysis revealed that elevated serum iron levels causally increase POAG risk. Patients with POAG exhibited increased iron and MDA levels alongside decreased GPX4 and GSH. We identified 14 ferroptosis-related differentially expressed genes, with PPI analysis pinpointing SLC2A3, SCD, and HBA1 as hub genes linking ferroptosis to TM injury. Their dysregulation amplified lipid peroxidation cascades. CMap screening and molecular docking suggested ATPase inhibitor digoxin as a potential POAG therapeutic. Digoxin significantly attenuated H2O2-induced ferroptosis in HTMCs by reducing MDA and restoring GPX4, ultimately lowering IOP in COH eyes.

Our findings establish digoxin as a promising therapeutic agent that suppresses ferroptosis and reduces IOP via the SLC2A3/SCD/HBA1 pathway, providing a transformative strategy for POAG treatment.