Brain HealthHow the Immunoproteasome Drives Alzheimer's Tau Buildup and Microglial Aging
Alzheimer's disease involves a destructive trifecta: tau protein tangles, impaired cellular waste disposal, and chronic brain inflammation. This review spotlights the immunoproteasome — a specialized protein-degradation machine — as a key player linking all three. The β5i/LMP7 subunit of the immunoproteasome is activated in brain immune cells called microglia and in neurons during inflammation. In microglia, chronic activation destroys an antioxidant regulator called NRF2, triggering inflammation and cellular senescence. In neurons, moderate activity helps clear damaged tau, but excessive activity produces tau fragments that spread through the brain. The review also examines how gut bacteria may remotely prime this system via the gut-brain axis. Crucially, partial — not total — suppression of immunoproteasome activity appears most promising therapeutically, suggesting LMP7 as a calibrated drug target for Alzheimer's.
