Alzheimer's disease (AD) is closely associated with synaptic dysfunction, and thus current treatments often aim to stimulate neurotransmission to improve cognitive impairment. Whereas the formation of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex is essential for synaptic transmission, the correlation between SNAREs and AD neuropathology is unknown. Here, we report that intracellular amyloid-β (Aβ) oligomers directly inhibit SNARE-mediated exocytosis by impairing SNARE complex formation. We observe abnormal reduction of SNARE complex levels in the brains of APP/PS1 transgenic (TG) mice compared to age-matched wild-types. We demonstrate that Aβ oligomers block SNARE complex assembly through the direct interaction with a target membrane (t)-SNARE syntaxin 1a in vitro. Furthermore, the results of the in vitro single-vesicle content-mixing assay reveal that Aβ oligomers inhibit SNARE-mediated fusion pores. Thus, our study identifies a potential molecular mechanism by which intracellular Aβ oligomers hamper SNARE-mediated exocytosis, likely leading to AD-associated synaptic dysfunctions.
Bibliographical noteFunding Information:
This work was supported by NIH grants (R01 GM051290; to Y.-K.S.), KIST Institutional Programs (2E25520 and 2E25023), KHIDI (HI14C3319), RF and the WISET Grant funded by the Ministry of Science (Republic of Korea), and MSIP under the Program for Returners into R&D (KW-2014-PPD-0076).
© 2015 The Authors.
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)