In:
The Journal of Neuroscience, Society for Neuroscience, Vol. 22, No. 1 ( 2002-01-01), p. 10-20
Abstract:
The increased production of amyloid β-peptide (Aβ) in Alzheimer's disease is acknowledged to be a key pathogenic event. In this study, we examined the response of primary human and rat brain cortical cultures to Aβ administration and found a marked increase in the tyrosine phosphorylation content of numerous neuronal proteins, including tau and putative microtubule-associated protein 2c (MAP2c). We also found that paired helical filaments of aggregated and hyperphosphorylated tau are tyrosine phosphorylated, indicating that changes in the phosphotyrosine content of cytoplasmic proteins in response to Aβ are potentially an important process. Increased tyrosine phosphorylation of cytoskeletal and other neuronal proteins was specific to fibrillar Aβ 25–35 and Aβ 1–42 . The tyrosine phosphorylation was blocked by addition of the Src family tyrosine kinase inhibitor 4-amino-5-(4-chlorophenyl)-7( t -butyl)pyrazol(3,4- d )pyramide (PP2) and the phosphatidylinositol 3-kinase inhibitor LY 294002. Tyrosine phosphorylation of tau and MAP2c was concomitant with an increase in the tyrosine phosphorylation and subsequent putative activation of the non-receptor kinase, focal adhesion kinase (FAK). Immunoprecipitation of Fyn, a member of the Src family, from Aβ 25–35 -treated neurons showed an increased association of Fyn with FAK. Aβ treatment of cells also stimulated the sustained activation of extracellular regulated kinase-2, which was blocked by addition of PP2 and LY 294002, suggesting that FAK/Fyn/PI3-kinase association is upstream of mitogen-activated protein (MAP) kinase signaling in Aβ-treated neurons. This cascade of signaling events contains the earliest biochemical changes in neurons to be described in response to Aβ exposure and may be critical for subsequent neurodegenerative changes.
Type of Medium:
Online Resource
ISSN:
0270-6474
,
1529-2401
DOI:
10.1523/JNEUROSCI.22-01-00010.2002
Language:
English
Publisher:
Society for Neuroscience
Publication Date:
2002
detail.hit.zdb_id:
1475274-8
SSG:
12
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