Selective coactivation of α7- and α4β2-nicotinic acetylcholine receptors reverses beta-amyloid-induced synaptic dysfunction.

Autor:	Roberts JP; Molecular, Cellular and Integrative Neurosciences Program, Colorado State University, Fort Collins, Colorado, USA; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA., Stokoe SA; Molecular, Cellular and Integrative Neurosciences Program, Colorado State University, Fort Collins, Colorado, USA; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA., Sathler MF; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA., Nichols RA; Department of Cell and Molecular Biology, University of Hawai'i at Manoa, Honolulu, Hawaii, USA., Kim S; Molecular, Cellular and Integrative Neurosciences Program, Colorado State University, Fort Collins, Colorado, USA; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA. Electronic address: seonil.kim@colostate.edu.
Jazyk:	angličtina
Zdroj:	The Journal of biological chemistry [J Biol Chem] 2021 Jan-Jun; Vol. 296, pp. 100402. Date of Electronic Publication: 2021 Feb 09.
DOI:	10.1016/j.jbc.2021.100402
Abstrakt:	Beta-amyloid (Aβ) has been recognized as an early trigger in the pathogenesis of Alzheimer's disease (AD) leading to synaptic and cognitive impairments. Aβ can alter neuronal signaling through interactions with nicotinic acetylcholine receptors (nAChRs), contributing to synaptic dysfunction in AD. The three major nAChR subtypes in the hippocampus are composed of α7-, α4β2-, and α3β4-nAChRs. Aβ selectively affects α7- and α4β2-nAChRs, but not α3β4-nAChRs in hippocampal neurons, resulting in neuronal hyperexcitation. However, how nAChR subtype selectivity for Aβ affects synaptic function in AD is not completely understood. Here, we showed that Aβ associated with α7- and α4β2-nAChRs but not α3β4-nAChRs. Computational modeling suggested that two amino acids in α7-nAChRs, arginine 208 and glutamate 211, were important for the interaction between Aβ and α7-containing nAChRs. These residues are conserved only in the α7 and α4 subunits. We therefore mutated these amino acids in α7-containing nAChRs to mimic the α3 subunit and found that mutant α7-containing receptors were unable to interact with Aβ. In addition, mutant α3-containing nAChRs mimicking the α7 subunit interact with Aβ. This provides direct molecular evidence for how Aβ selectively interacted with α7- and α4β2-nAChRs, but not α3β4-nAChRs. Selective coactivation of α7- and α4β2-nAChRs also sufficiently reversed Aβ-induced AMPA receptor dysfunction, including Aβ-induced reduction of AMPA receptor phosphorylation and surface expression in hippocampal neurons. Moreover, costimulation of α7- and α4β2-nAChRs reversed the Aβ-induced disruption of long-term potentiation. These findings support a novel mechanism for Aβ's impact on synaptic function in AD, namely, the differential regulation of nAChR subtypes. Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article. (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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