Functional impairment of cortical AMPA receptors in schizophrenia.
journal contributionposted on 15.03.2021, 09:59 by Tommaso Zeppillo, Anton Schulmann, Fabio Macciardi, Brooke E Hjelm, Melanie FockingMelanie Focking, P Adolfo Sequeira, Ilaria Guella, David CotterDavid Cotter, William E Bunney, Agenor Limon, Marquis P Vawter
Clinical and preclinical studies suggest that some of the behavioral alterations observed in schizophrenia (SZ) may be mechanistically linked to synaptic dysfunction of glutamatergic signaling. Recent genetic and proteomic studies suggest alterations of cortical glutamate receptors of the AMPA-type (AMPARs), which are the predominant ligand-gated ionic channels of fast transmission at excitatory synapses. The impact of gene and protein alterations on the electrophysiological activity of AMPARs is not known in SZ. In this proof of principle work, using human postmortem brain synaptic membranes isolated from the dorsolateral prefrontal cortex (DLPFC), we combined electrophysiological analysis from microtransplanted synaptic membranes (MSM) with transcriptomic (RNA-Seq) and label-free proteomics data in 10 control and 10 subjects diagnosed with SZ. We observed in SZ a reduction in the amplitude of AMPARs currents elicited by kainate, an agonist of AMPARs that blocks the desensitization of the receptor. This reduction was not associated with protein abundance but with a reduction in kainate's potency to activate AMPARs. Electrophysiologically-anchored dataset analysis (EDA) was used to identify synaptosomal proteins that linearly correlate with the amplitude of the AMPARs responses, gene ontology functional annotations were then used to determine protein-protein interactions. Protein modules associated with positive AMPARs current increases were downregulated in SZ, while protein modules that were upregulated in SZ were associated with decreased AMPARs currents. Our results indicate that transcriptomic and proteomic alterations, frequently observed in the DLPFC in SZ, converge at the synaptic level producing a functional electrophysiological impairment of AMPARs.
NIA grant AG053740
NIMH grant MH08580
NIMH grant MH113177
Amon G. Carter Foundation
CommentsThe original article is available at https://www.sciencedirect.com
Published CitationZeppillo T, Schulmann A, Macciardi F, Hjelm BE, Föcking M, Sequeira PA, Guella I, Cotter D, Bunney WE, Limon A, Vawter MP. Functional impairment of cortical AMPA receptors in schizophrenia. Schizophrenia Research. 2020 :S0920-9964(20)30147-X.
Publication Date6 June 2020
- Beaumont Hospital
- Neurological and Psychiatric Disorders
- Accepted Version (Postprint)