Role of NDUFS1 in mitochondrial dysfunction and oxidative stress in glaucomatous retinal ganglion cells

This study investigates the role of NDUFS1, a subunit of mitochondrial complex I, in glaucomatous retinal ganglion cell (RGC) injury and determines whether it mediates RGC apoptosis through regulating mitochondrial dysfunction and oxidative stress (OS). A microbead-induced glaucoma mouse model was established. Intraocular pressure (IOP) measurements, retinal whole-mount immunofluorescence staining, TUNEL assay, and OS marker detection were conducted to assess RGC survival, apoptosis, and OS. In vitro, NDUFS1 was knocked down or overexpressed in R28 retinal cells. JC-1 staining, adenosine triphosphate (ATP) assay, and flow cytometry were employed to analyze the impacts of NDUFS1 on mitochondrial membrane potential, energy metabolism, OS, and apoptosis. Finally, adeno-associated virus-mediated NDUFS1 overexpression (AAV-oe-NDUFS1) was delivered via intravitreal injection to validate its protective effects in vivo. In vivo experiments revealed downregulation of NDUFS1 expression in the retinas of glaucoma mice, accompanied by significant RGC loss, enhanced OS, and increased apoptosis. In vitro, NDUFS1 knockdown induced mitochondrial membrane depolarization, reduced ATP synthesis, exacerbated OS, and ultimately promoted apoptosis. Conversely, NDUFS1 overexpression effectively reversed these pathological phenotypes. Rescue experiments in vivo further demonstrated that NDUFS1 upregulation alleviated OS, suppressed apoptosis, and significantly improved RGC survival. NDUFS1 downregulation plays a critical role in glaucomatous RGC injury. Overexpression of NDUFS1 improves mitochondrial function, attenuates OS, and enhances cell survival. The study provides novel mechanistic insights into neuroprotection in glaucoma and suggests NDUFS1 as a potential therapeutic target.