NF-κB Involvement in Glaucoma-Associated Neuroinflammation: Focus on Glial Cells

Glaucoma is a complex neurodegenerative disease characterized by the progressive loss of retinal ganglion cells (RGCs) and optic nerve damage. Both mechanical and vascular factors are believed to contribute to the etiology of glaucoma. However, the underlying pathogenic mechanisms are not yet fully understood. In this article, although it is a single component of a multifactorial condition, we argue that neuroinflammation is a significant factor in glaucoma pathogenesis. Glaucoma, at present, is recognized as a neurodegenerative disorder sharing common neuroinflammatory mechanisms with classical neurodegenerative diseases. The involvement of classical immune signaling pathways, such as TLRs and NF-κB, as well as proinflammatory cytokines like TNF-α, aligns glaucoma with other neurodegenerative diseases where inflammation is pivotal (e.g., Parkinson's and Alzheimer's diseases). As such, glaucoma should be considered not only an ocular pressure disorder but also a neurodegenerative condition with a strong immune component. This perspective opens new avenues for novel therapeutic intervention, including the targeting of glial cells or modulators of inflammatory signaling. However, the complexity of microglial phenotypes and the timing of their activation relative to astrocytes remain areas that require further clarification. The current M1/M2 paradigm is acknowledged as overly simplistic, highlighting the need for more refined and nuanced models. Although oxidative stress and other interconnected signaling, such as STAT3, are involved in the pathogenesis of glaucoma, here, we focus on the role of the NF-κB signaling pathway within the glaucomatous condition with a special focus on the main characters fostering the neuroinflammation.