TY - JOUR
T1 - Inhibition of AKT Signaling Alters βIV Spectrin Distribution at the AIS and Increases Neuronal Excitability
AU - Di Re, Jessica
AU - Hsu, Wei Chun J.
AU - Kayasandik, Cihan B.
AU - Fularczyk, Nickolas
AU - James, T. F.
AU - Nenov, Miroslav
AU - Negi, Pooran
AU - Marosi, Mate
AU - Scala, Federico
AU - Prasad, Saurabh
AU - Labate, Demetrio
AU - Laezza, Fernanda
N1 - Publisher Copyright:
© Copyright © 2021 Di Re, Hsu, Kayasandik, Fularczyk, James, Nenov, Negi, Marosi, Scala, Prasad, Labate and Laezza.
PY - 2021/6/30
Y1 - 2021/6/30
N2 - The axon initial segment (AIS) is a highly regulated subcellular domain required for neuronal firing. Changes in the AIS protein composition and distribution are a form of structural plasticity, which powerfully regulates neuronal activity and may underlie several neuropsychiatric and neurodegenerative disorders. Despite its physiological and pathophysiological relevance, the signaling pathways mediating AIS protein distribution are still poorly studied. Here, we used confocal imaging and whole-cell patch clamp electrophysiology in primary hippocampal neurons to study how AIS protein composition and neuronal firing varied in response to selected kinase inhibitors targeting the AKT/GSK3 pathway, which has previously been shown to phosphorylate AIS proteins. Image-based features representing the cellular pattern distribution of the voltage-gated Na+ (Nav) channel, ankyrin G, βIV spectrin, and the cell-adhesion molecule neurofascin were analyzed, revealing βIV spectrin as the most sensitive AIS protein to AKT/GSK3 pathway inhibition. Within this pathway, inhibition of AKT by triciribine has the greatest effect on βIV spectrin localization to the AIS and its subcellular distribution within neurons, a phenotype that Support Vector Machine classification was able to accurately distinguish from control. Treatment with triciribine also resulted in increased excitability in primary hippocampal neurons. Thus, perturbations to signaling mechanisms within the AKT pathway contribute to changes in βIV spectrin distribution and neuronal firing that may be associated with neuropsychiatric and neurodegenerative disorders.
AB - The axon initial segment (AIS) is a highly regulated subcellular domain required for neuronal firing. Changes in the AIS protein composition and distribution are a form of structural plasticity, which powerfully regulates neuronal activity and may underlie several neuropsychiatric and neurodegenerative disorders. Despite its physiological and pathophysiological relevance, the signaling pathways mediating AIS protein distribution are still poorly studied. Here, we used confocal imaging and whole-cell patch clamp electrophysiology in primary hippocampal neurons to study how AIS protein composition and neuronal firing varied in response to selected kinase inhibitors targeting the AKT/GSK3 pathway, which has previously been shown to phosphorylate AIS proteins. Image-based features representing the cellular pattern distribution of the voltage-gated Na+ (Nav) channel, ankyrin G, βIV spectrin, and the cell-adhesion molecule neurofascin were analyzed, revealing βIV spectrin as the most sensitive AIS protein to AKT/GSK3 pathway inhibition. Within this pathway, inhibition of AKT by triciribine has the greatest effect on βIV spectrin localization to the AIS and its subcellular distribution within neurons, a phenotype that Support Vector Machine classification was able to accurately distinguish from control. Treatment with triciribine also resulted in increased excitability in primary hippocampal neurons. Thus, perturbations to signaling mechanisms within the AKT pathway contribute to changes in βIV spectrin distribution and neuronal firing that may be associated with neuropsychiatric and neurodegenerative disorders.
KW - AIS plasticity
KW - GSK3 – glycogen synthase kinase 3
KW - WEE1 kinase
KW - confocal imaging
KW - patch clamp electrophysiology
KW - support vector machine classification
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UR - http://www.scopus.com/inward/citedby.url?scp=85110154222&partnerID=8YFLogxK
U2 - 10.3389/fnmol.2021.643860
DO - 10.3389/fnmol.2021.643860
M3 - Article
C2 - 34276302
AN - SCOPUS:85110154222
SN - 1662-5099
VL - 14
JO - Frontiers in Molecular Neuroscience
JF - Frontiers in Molecular Neuroscience
M1 - 643860
ER -