Oligomeric beta-amyloid(1-42) induces the expression of Alzheimer disease-relevant proteins in cholinergic SN56.B5.G4 cells as revealed by proteomic analysis.
Alzheimer's disease (AD) is characterized by cholinergic dysfunction and progressive basal forebrain cell loss which has been hypothesized to be associated with extensive accumulation of beta-amyloid (Abeta). To reveal whether oligomeric Abeta displays a particular toxicity for cholinergic neurons, the cholinergic cell line SN56.B5.G4 (SN56) was used as a model. Recently performed microarray analyses demonstrated that genes affected by exposure of SN56 cells with 50 microM oligomeric Abeta(1-42) for 24 h were involved in protein modification and degradation [Heinitz, K., Beck, M., Schliebs, R., Perez-Polo, J.R., 2006. Toxicity mediated by soluble oligomers of beta-amyloid(1-42) on cholinergic SN56.B5.G4 cells. J. Neurochem. 98, 1930-1945]. Using a proteomic approach, we compared the levels of proteins and specially of phosphorylated proteins in cytosolic fractions of cell lysates from cholinergic SN56 cells exposed to 50 microM Abeta(1-42) for 24h to those in control incubations. We show here that the levels of calreticulin, and mitogen-activated protein kinase (MAPK) kinase 6c were up-regulated in cholinergic SN56 cells exposed to Abeta(1-42), while gamma-actin appeared down-regulated. Abeta(1-42) exposure of cholinergic SN56 cells led to decreased phosphorylation of phosphoproteins, such as the Rho GDP dissociation inhibitor, the ubiquitin carboxyl terminal hydrolase-1, and the tubulin alpha-chain isotype Malpha6, as compared to untreated control lysates. The proteins identified have also been reported to be affected in brains of AD patients, suggesting a potential role of Abeta in influencing the integrity and functioning of the proteome in AD.
Joerchel
Sabrina
S
Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany.
Raap
Maik
M
Bigl
Marina
M
Eschrich
Klaus
K
Schliebs
Reinhard
R
D000544:Alzheimer Disease / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000378:metabolism / Q000633:toxicity*; D000818:Animals; D037282:Calreticulin / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D002799:Cholinergic Fibers / Q000187:drug effects / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D048669:MAP Kinase Kinase 6 / Q000378:metabolism; D013058:Mass Spectrometry; D051379:Mice; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism / Q000633:toxicity*; D010766:Phosphorylation / Q000187:drug effects; D020543:Proteome / Q000187:drug effects / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D012686:Septal Nuclei / Q000378:metabolism* / Q000503:physiopathology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D016229:Amyloid beta-Peptides; D037282:Calreticulin; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D020543:Proteome; C075222:amyloid beta-protein (1-42); D048669:MAP Kinase Kinase 6