Asparagine Deamidation Attenuates Toxicity, Aggregation, and Microglial Responses of Alzheimer's Amyloid-β

Alzheimer's disease (AD) is a growing global challenge that imposes a tremendous burden on society and economies. Though recently approved anti-amyloid β (Aβ) immunotherapies show effectiveness in clearing amyloid and slowing cognitive decline, the removal of cerebral Aβ can also cause serious adverse events (SAEs). Therefore, decreasing the detrimental effects of Aβ in the brain without promoting SAEs is an unmet need in AD treatment. Here, we show that deamidation of Asparagine 27(N27) in Aβ1-42 can significantly reduce Aβ's neurotoxicity and decrease selective microglial pro-inflammatory cytokine production. We also show that deamidation of N27 produces a pronounced decrease in Aβ's aggregation propensity and decreases soluble oligomer formation, suggesting a potential mechanism for its mitigation of Aβ's detrimental cellular effects. Modulation of these Aβ properties by N27 deamidation represents a proof of concept for a potential strategy to alter the detrimental effects of Aβ that may not require its removal from the brain. Our findings on reducing Aβ's toxic properties by N27 deamidation may provide a basis for future therapeutic interventions.