Fig. 2
From: Genetics ignite focus on microglial inflammation in Alzheimer’s disease
Microglial activation can be neuroprotective and/or neurotoxic; the actions of AD risk proteins modulate these effects. The normal actions of CD33 and SHIP1 (encoded by INPP5D) appear to antagonize both forms of microglial activation, while CR1 action appears to promote both Aβ phagocytosis and the production of neurotoxic pro-inflammatory cytokines such as TNF. TREM2 appears to promote phagocytosis while dampening pro-inflammatory cytokine production. ABCA7 helps to mediate phagocytosis. APOE2 and APOE3 are anti-inflammatory, while APOE4 promotes inflammation and neurotoxicity