Glycosylation-driven necroptosis in retinal degeneration: dual rescue by AAV8 gene therapy and RIPK1 inhibition.

Glycosylation defects are increasingly implicated across neurodegenerative diseases, yet the mechanism by which perturbed O-mannosylation drives neuronal death-and how to reverse it-remains unclear. Here we show that a disease-associated POMGnT1 L120R mutation produces widespread retinal neurodegeneration by coupling metabolic collapse to necroptosis. In mice harboring the human POMGnT1 L120R allele and in POMGnT1-knockout human RPE cells, hypoglycosylation of key substrates (α-dystroglycan and ENO1) coincides with strengthened SAG-ENO1 interaction, reduced glycolytic capacity, ATP shortfall, Golgi fragmentation, tight-junction failure, and robust activation of the RIPK1/RIPK3/MLKL cascade; notably, degeneration proceeds with minimal apoptotic signatures. Two orthogonal interventions-AAV8-mediated POMGnT1 gene augmentation and pharmacologic RIPK1 inhibition (RIPA-56)-each suppress necroptotic signaling, restore barrier integrity, and rescue visual function in vivo. These data define a glycosylation-metabolism-necroptosis axis that generalizes beyond a single gene or tissue and motivate a mutation-independent therapeutic blueprint: repair the upstream glycosylation deficit and/or block the downstream necroptotic execution pathway. Our findings position O-mannosylation homeostasis as a tractable control point for neuroprotection and nominate combined gene-augmentation and kinase-inhibition strategies for glycosylation-linked neurodegeneration.