Perineuronal Net Protein Neurocan Inhibits NCAM/EphA3 Repellent Signaling in GABAergic Interneurons.
Sci Rep
; 8(1): 6143, 2018 04 18.
Article
em En
| MEDLINE
| ID: mdl-29670169
ABSTRACT
Perineuronal nets (PNNs) are implicated in closure of critical periods of synaptic plasticity in the brain, but the molecular mechanisms by which PNNs regulate synapse development are obscure. A receptor complex of NCAM and EphA3 mediates postnatal remodeling of inhibitory perisomatic synapses of GABAergic interneurons onto pyramidal cells in the mouse frontal cortex necessary for excitatory/inhibitory balance. Here it is shown that enzymatic removal of PNN glycosaminoglycan chains decreased the density of GABAergic perisomatic synapses in mouse organotypic cortical slice cultures. Neurocan, a key component of PNNs, was expressed in postnatal frontal cortex in apposition to perisomatic synapses of parvalbumin-positive interneurons. Polysialylated NCAM (PSA-NCAM), which is required for ephrin-dependent synapse remodeling, bound less efficiently to neurocan than mature, non-PSA-NCAM. Neurocan bound the non-polysialylated form of NCAM at the EphA3 binding site within the immunoglobulin-2 domain. Neurocan inhibited NCAM/EphA3 association, membrane clustering of NCAM/EphA3 in cortical interneuron axons, EphA3 kinase activation, and ephrin-A5-induced growth cone collapse. These studies delineate a novel mechanism wherein neurocan inhibits NCAM/EphA3 signaling and axonal repulsion, which may terminate postnatal remodeling of interneuron axons to stabilize perisomatic synapses in vivo.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Transdução de Sinais
/
Receptores Proteína Tirosina Quinases
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Moléculas de Adesão de Célula Nervosa
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Neurocam
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Neurônios GABAérgicos
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Interneurônios
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Sci Rep
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Estados Unidos