Injection of exogenous amyloid-β oligomers aggravated cognitive deficits, and activated necroptosis, in APP23 transgenic mice

Abstract

Alzheimer's disease (AD) is a neurodegenerative disease that is characterized by the loss of synapses and neurons in the brain, and the accumulation of amyloid plaques. Aβ oligomers (AβO) play a critical role in the pathogenesis of AD. Although there is increasing evidence to support the involvement of necroptosis in the pathogenesis of AD, the exact mechanism remains elusive. In the present study, we explored the effect of exogenous AβO injection on cell necroptosis and cognitive deficits in APP23 transgenic mice. We found that intrahippocampal injection of AβO accelerated the development of AD pathology and caused cognitive impairment in APP23 mice. Specifically, AβO injection significantly accelerated the accumulation of AβO and increased the expression level of phosphorylated-tau, and also induced necroptosis. Behavioral tests showed that AβO injection was associated with cognitive impairment. Furthermore, necroptosis induced by AβO injection occurred predominantly in microglia of the AD brain. We speculate that AβO increased necroptosis by activating microglia, resulting in cognitive deficits. Our results may aid in an understanding of the role played by AβO in AD from an alternative perspective and provide new ideas and evidence for necroptosis as a potential intervention and therapeutic target for AD.

Keywords: Alzheimer's disease (AD); Amyloid-β oligomers (AβO); Microglia; Necroptosis; Neurodegeneration.