Erythropoiesis-inosine metabolic axis failure underlying retinal neurodegeneration in glaucoma: novel diagnoses and therapies.

Abstract

Glaucoma, long considered an ocular-limited, age-dependent and hypoxia-driven neurodegeneration, is here reframed as a systemic erythroid-inosine axis failure that originates in the bone marrow yet culminates in retinal ganglion cell (RGC) death. By mining UK Biobank datasets (n = 127,028) and validating our findings in an independent clinical cohort (n = 178), we reveal that glaucoma is preceded by dyserythropoiesis and a compensatory, AMPK-driven metabolic rewiring of mature erythrocytes that hypercatabolizes inosine to enhance oxygen unloading. This adaptation collapses when accelerated erythrocyte inosine metabolism drains systemic pools, starving high-energy demand hematopoietic progenitors, driving retinal microenvironment hypoxia and accelerating RGC loss. Genetic ablation of murine erythroid equilibrative nucleoside transporter 1 (ENT1) recapitulates the hallmark features of patients with glaucoma, including impaired erythropoiesis, reduced oxygen delivery, retinal hypoxia and RGC apoptosis in both age and intraocular pressure-induced glaucoma models. Conversely, inosine repletion reconstitutes erythroid output, restores oxygen delivery from mature erythrocytes and halts neurodegeneration in inducible glaucoma models. A ten-metabolite erythrocyte signature centered on inosine metabolism offers diagnostic potential. Altogether, our work redefines glaucoma as the first treatable systemic erythroid-driven hypoxic syndrome, positioning inosine as a pleiotropic metabolic rescue factor for neurodegeneration and a powerful biomarker for intercepting hypoxia-driven pathologies across organs.