Protective Role of Microglia on Neuronal Survival after Exposure to Amyloid Beta.

Alzheimer's disease (AD) is the most common cause of neurodegeneration. It is characterized by deposits of amyloid beta (Aβ) plaques and impaired memory. Microglia are associated with AD. They are activated in the AD brain and AD models. However, the exact role of microglia has not been established. We thus investigated the role of microglia in AD models using a primary culture and an ex-vivo assay. We showed that oligomerized Aβ is toxic to neurons in the primary culture. In the ex-vivo assay, a microglial cell line removed amyloid plaques in the brain of 5XFAD (AD model) mice. To verify if microglia can be protective for the neuron, we co-cultured neurons with primary microglia and treated them with Aβ. The loss of neurons, induced by amyloid toxicity, was attenuated by co-cultured microglia. Taken together, our data suggest that microglia promote neuronal survival by phagocytic clearance of Aβ in AD models.