Oligomeric β‐amyloid(1‐42) induces the expression of Alzheimer disease‐relevant proteins in cholinergic SN56.B5.G4 cells as revealed by proteomic analysis

Abstract

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.

Effects of Estrogen on Beta-Amyloid-Induced Cholinergic Cell Death in the Nucleus Basalis Magnocellularis

“…Both Aβ and E2 generate widespread changes in the brain by controlling gene expression among others [22,28,29,30,31], inducing cell death or preparing cells for toxicity and altering cellular reactions to Aβ. In our present study, by searching for possible target proteins, we aimed to find the mechanisms and raise a hypothesis underlying Aβ toxicity on cholinergic neurons and the possible neuroprotective effects of E2 in vivo.…”

Proteomic analysis of cells exposed to prefibrillar aggregates of HypF-N

“…In Table 3 a comparison between the protein identified in our study and the proteins identified in other studies is shown, indicating that there is a general response of cells to toxic aggregates that is not sequence specific [12,13,30,31,32]. Actually, changes in the expression levels of Gapdh, actin, tubulin and heat shock proteins have frequently been reported in amyloid-linked proteomic studies possibly because they are related to a generic response to stress conditions [33] such as that associated with the growth of amyloid aggregates.…”

“…Such a complex pattern of cell impairment makes proteomics one of the most useful tools to integrate these modifications into a whole systematic picture. The reports that recently appeared on the proteomic analysis of amyloid diseases such as Alzheimer's disease, Parkinson's disease and others have provided valuable data on some cell modifications allowing to explain, at least in part, cell impairment in these diseases [12][13][14][15][16]. Proteomic studies provided useful information on the changes in pattern of protein expression in cells exposed to toxic aggregates of specific peptides/proteins found aggregated in the corresponding diseases.…”

Analysis of mice brain and SH-SY5Y neuroblastoma cell proteome by quantitative two-dimensional electrophoresis

“…Besides animal models, various cell lines (e.g. SH-SY5Y human neuroblastoma) have been also developed to study the toxic effect of Aβ peptide and to analyse the neuron-specific proteome changes (David et al 2006, Joerchel et al 2008. Human APP transfected SH-SY5Y cells show alterations in mitochondrial respiratory functions and energy metabolism (Rhein et al 2009).…”

“…P301L tau expressing SH-SY5Y cells revealed that a significant fraction of proteins altered after fibrillar Aβ1-42 treatment (David et al 2006). The treatment of cholinergic SN56 cells by oligomeric Aβ1-42 also displayed alterations in the expression and phosphorylation levels of a number of proteins (Joerchel et al 2008). To demonstrate the reproducibility and reliability of our 2-DE workflow, normalised spot volumes were used to calculate the median CV% for each group.…”