Purinergic Receptor P2Y12-Mediated Tau Internalization in Microglia.

Microglia are the resident brain macrophage cells that are involved in constant surveillance of brain microenvironment. In Alzheimer's disease, microglia get over activated upon the accumulation of Tau and amyloid-β species in the extracellular space, ultimately leading to neurodegeneration. Microglia phagocytose the extracellular Tau species by several mechanisms among which P2Y12 receptor-mediated internalization of extracellular Tau is recently studied. Extracellular Tau activates microglia and directly interacts with the P2Y12 receptor. Tau-receptor complex is then internalized followed by perinuclear accumulation and lysosomal degradation. Upon microglial activation by extracellular Tau, P2Y12 receptor is also involved in membrane-associated actin remodeling which has its key role in active migration and phagocytosis.