The American journal of pathology
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Experimental therapies for Alzheimer's disease (AD) are focused on enhanced clearance of neurotoxic Abeta peptides from brain. Microglia can be neuroprotective by phagocytosing Abeta; however, this comes at the cost of activated innate immunity that causes paracrine damage to neurons. Here, we show that ablation of E prostanoid receptor subtype 2 (EP2) significantly increased microglial-mediated clearance of Abeta peptides from AD brain sections and enhanced microglial Abeta phagocytosis in cell culture. ⋯ This suggested that microglial activation is negatively regulated by EP2 signaling through suppression of prophagocytic cytokine secretion. However, despite this enhancement of Abeta phagocytosis, lack of EP2 completely suppressed Abeta-activated microglia-mediated paracrine neurotoxicity. These data demonstrate that blockade of microglial EP2 is a highly desirable mechanism for AD therapy that can maximize neuroprotective actions while minimizing bystander damage to neurons.