Introduction: Extracellular vesicles (EVs) have been implicated in the spread of neuropathology in Alzheimer's disease (AD), but their involvement in behavioral outcomes linked to AD remains to be determined.
Methods: EVs isolated from post mortem brain tissue from control, AD, or frontotemporal dementia (FTD) donors, as well as from APP/PS1 mice, were injected into the hippocampi of wild-type (WT) or a humanized Tau mouse model (hTau/mTauKO). Memory tests were carried out. Differentially expressed proteins in EVs were assessed by proteomics.
Results: Both AD-EVs and APP/PS1-EVs trigger memory impairment in WT mice. We further demonstrate that AD-EVs and FTD-EVs carry Tau protein, present altered protein composition associated with synapse regulation and transmission, and trigger memory impairment in hTau/mTauKO mice.
Discussion: Results demonstrate that AD-EVs and FTD-EVs have negative impacts on memory in mice and suggest that, in addition to spreading pathology, EVs may contribute to memory impairment in AD and FTD.
Highlights: Aβ was detected in EVs from post mortem AD brain tissue and APP/PS1 mice. Tau was enriched in EVs from post mortem AD, PSP and FTD brain tissue. AD-derived EVs and APP/PS1-EVs induce cognitive impairment in wild-type (WT) mice. AD- and FTD-derived EVs induce cognitive impairment in humanized Tau mice. Proteomics findings associate EVs with synapse dysregulation in tauopathies.
Keywords: Alzheimer's disease; brain-derived EVs; extracellular vesicles; proteomics; tauopathies.
© 2023 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.