Nerve Growth Factor Shows Promise Against Glaucoma by Calming Oxidative Stress and Brain Inflammation

Glaucoma remains the leading cause of irreversible blindness worldwide, and for decades its treatment has been confined to a single strategy: lowering intraocular pressure. While pressure-reducing eye drops, laser procedures, and surgical interventions can slow the disease, a substantial proportion of patients continue to lose retinal ganglion cells—the projection neurons of the eye—even after their pressure appears well controlled. Now, new research published in Cell Death Discovery suggests that a recombinant form of a classic neurotrophic molecule, human recombinant nerve growth factor (rhNGF), may offer what the field has long sought: a genuinely neuroprotective therapy that preserves vision by targeting the cellular stress and inflammatory processes that kill retinal neurons.

The study, conducted in a mouse model of glaucoma, demonstrates that administration of rhNGF protects retinal ganglion cells from degeneration and preserves visual function. Crucially, the investigators did not stop at showing that the treatment worked; they dissected the mechanisms underlying the benefit, revealing that rhNGF counteracts two intertwined drivers of glaucomatous damage—oxidative stress and neuroinflammation. This dual action positions nerve growth factor not merely as a survival signal for ailing neurons, but as a molecular shield against the hostile retinal environment that develops as the disease progresses.

Nerve growth factor was the first neurotrophin ever discovered, identified more than seventy years ago by Rita Levi-Montalcini and Stanley Cohen, work that earned the Nobel Prize in Physiology or Medicine in 1986. NGF is best known for its role in the development and maintenance of sympathetic and sensory neurons, but it also acts on the central nervous system, including the retina, where its receptors—TrkA and p75NTR—are expressed by retinal ganglion cells and by glial cells such as Müller cells and astrocytes. Over the years, evidence has accumulated that NGF signaling can promote neuronal survival, yet translating that biology into a practical therapy has been difficult, in part because delivering protein drugs to target tissues is challenging and because earlier clinical efforts were hampered by formulation and delivery limitations.

In the glaucoma model used in the study, elevated intraocular pressure triggers a cascade of degenerative events in the retina. Pressure insult compromises axonal transport at the optic nerve head, deprives ganglion cells of trophic support, and sets off a vicious cycle in which stressed neurons release damage signals that activate glial cells. Activated microglia and macroglia, in turn, release pro-inflammatory cytokines such as TNF-alpha and interleukin-1 beta and generate reactive oxygen species, further injuring neurons and perpetuating the inflammatory loop. The result is progressive loss of retinal ganglion cells, thinning of the nerve fiber layer, and deterioration of the visual responses that these cells convey to the brain.

When the researchers administered rhNGF to the glaucomatous mice, they observed a marked preservation of retinal structure and function compared with untreated animals. Histological analysis revealed significantly higher survival of retinal ganglion cells, and functional assessments of the visual pathway confirmed that the anatomical protection translated into preserved vision-related output. The magnitude of the effect indicates that rhNGF does not merely delay degeneration marginally but provides substantive neuroprotection in this experimental setting.

The mechanistic findings are arguably the most significant contribution of the work. Molecular analyses of treated retinas showed a pronounced reduction in markers of oxidative stress. Levels of reactive oxygen species and lipid peroxidation products fell, while endogenous antioxidant defenses were bolstered. This matters because oxidative damage is now recognized as a central pillar of glaucoma pathobiology: the retina is one of the most oxygen-demanding tissues in the body, its ganglion cell mitochondria are exceptionally vulnerable, and oxidative modifications to proteins, lipids, and DNA accumulate early in the disease and correlate with neuronal loss. By damping oxidative injury, rhNGF appears to interrupt one of the key upstream triggers of the degenerative cascade.

Equally important was the effect on neuroinflammation. In untreated glaucomatous retinas, the researchers documented robust activation of microglia—the resident immune cells of the retina and optic nerve—along with elevated expression of inflammatory cytokines. In rhNGF-treated animals, microglial activation was substantially attenuated and the inflammatory signature was blunted. This anti-inflammatory action is notable because it suggests that NGF signaling, in addition to its classical trophic role, actively reprograms the glial response to injury. The TrkA receptor, when engaged by NGF, can activate survival pathways such as PI3K-Akt and MAPK signaling in neurons, while modulating the reactivity of glial cells that would otherwise amplify tissue damage. The study’s data indicate that both dimensions of NGF biology—direct neuronal support and immunomodulation—contribute to the observed protection.

The interplay between oxidative stress and inflammation is what makes these findings particularly compelling. These two processes are not independent; reactive oxygen species can activate inflammatory signaling pathways, including the NF-kappaB and inflammasome pathways, and inflammatory cells are themselves major producers of free radicals. In glaucoma, this creates a self-reinforcing spiral in which each process feeds the other. A therapy that targets only one arm of the spiral may achieve limited benefit, whereas an intervention that simultaneously reduces oxidative damage and suppresses neuroinflammation can potentially break the cycle. The rhNGF results suggest that the molecule does precisely that, which may explain why the neuroprotection achieved in the mouse model was so robust.

The therapeutic implications extend beyond the laboratory. Recombinant human NGF has already navigated part of the translational path: a topical ocular formulation of rhNGF has been approved in Europe for the treatment of neurotrophic keratitis, a disease of corneal nerve degeneration, providing clinical precedent for the safety and feasibility of delivering this protein to the eye. The new findings raise the prospect of repurposing or reformulating rhNGF for glaucoma, potentially as an adjunct to pressure-lowering therapy. Such a combination would address both sides of the disease: intraocular pressure as the major modifiable risk factor, and the downstream neurodegenerative processes that pressure control alone cannot fully halt. For the millions of patients who continue to progress despite adequate pressure management, a neuroprotective add-on would represent a genuine paradigm shift.

Significant work remains before rhNGF can be considered a glaucoma therapy. The current evidence comes from an animal model, and mouse glaucoma models, while informative, do not capture every feature of the human disease, which unfolds over decades rather than weeks. Questions of dosing, delivery route, treatment timing, and long-term safety will need to be answered, and results will need to be replicated in additional models and ultimately in clinical trials. Nevertheless, the study provides a rigorous mechanistic foundation for the idea that nerve growth factor can protect the optic nerve in glaucoma, and it identifies oxidative stress and neuroinflammation as tractable, druggable targets. If the neuroprotective efficacy observed in mice can be reproduced in patients, rhNGF could become one of the first treatments in ophthalmology to preserve vision not by lowering pressure, but by directly defending the neurons that make sight possible.

Subject of Research: Neuroprotective efficacy of recombinant human nerve growth factor in a mouse model of glaucoma

Article Title: rhNGF shows neuroprotective efficacy by counteracting oxidative stress and neuroinflammation in a glaucoma mouse model

Article References: Vecchiotti, D., Di Vito Nolfi, M., Compagnoni, C., Miscione, M. S., Verzella, D., D’Andrea, D., Flati, I., Galli, F., d’Angelo, M., Angelucci, A., Cattani, F., Cimini, A., Tessitore, A., Capece, D., Alesse, E., Allegretti, M., & Zazzeroni, F. (2026). rhNGF shows neuroprotective efficacy by counteracting oxidative stress and neuroinflammation in a glaucoma mouse model. Cell Death Discovery. https://doi.org/10.1038/s41420-026-03345-y

Image Credits: AI Generated

DOI: 10.1038/s41420-026-03345-y

Keywords: glaucoma, rhNGF, nerve growth factor, neuroprotection, oxidative stress, neuroinflammation, retinal ganglion cells, intraocular pressure, microglia, optic nerve, TrkA receptor, Cell Death Discovery