Neurotoxicity induced by okadaic acid in the human neuroblastoma SH-SY5Y line can be differentially prevented by α7 and β2* nicotinic stimulation

A good model of neuronal death that reproduces the characteristic tau (τ) hyperphosphorylation of Alzheimeŕs disease is the use of okadaic acid (OA). The aim of this study was to determine the contribution of α7 and β2* nicotinic acetylcholine receptor (nAChR) subtypes to neuroprotection against OA...

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Bibliographic Details
Authors: del Barrio, Laura, Martín-de-Saavedra, María Dolores, Romero Jódar, Alejandro, Parada, Esther, Egea, Javier, Ávila, Jesús, McIntosh, John Michael, Wonnacott, Susan, López, Manuela G.
Format: article
Status:Published version
Publication Date:2011
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/252145
Online Access:http://hdl.handle.net/10261/252145
Access Level:Open access
Keyword:Okadaic acid
SH-SY5Y neuroblastoma
Nicotinic receptors
Hyperphosphorylation of tau
PNU 282987
5IA 85380.
Description
Summary:A good model of neuronal death that reproduces the characteristic tau (τ) hyperphosphorylation of Alzheimeŕs disease is the use of okadaic acid (OA). The aim of this study was to determine the contribution of α7 and β2* nicotinic acetylcholine receptor (nAChR) subtypes to neuroprotection against OA in the SHSY5Y cell line by using the selective α7 and β2* nAChR agonists PNU 282987 and 5-Iodo-A85380, respectively. The results of this study show that both α7 and β2* nAChR can afford neuroprotection against OA-induced neurotoxicity. Protection mediated by α7 nAChRs was independent of Ca and involved the intracellular signaling pathway Janus Kinase-2/Phosphatidylinositol-3-kinase/Akt. When Ca entry was promoted through the α7 nAChR by using the α7-selective positive allosteric modulator PNU 120596, protection was lost. By contrast, protection mediated by β2* nAChRs was Ca dependent and implicated the signaling pathways PI3K/Akt and extracellular regulated kinase 1/2. Both α7 and β2* nAChR activation converged on downregulation of GSK-3β and reduction of τ phosphorylation in cells undergoing cell death induced by OA. Therefore, targeting nAChR could offer a strategy for reducing neurodegeneration secondary to hyperphosphorylation of protein τ.