Alzheimer's disease is characterized mainly by loss of neurons from the septal nucleus. In this study, neurons from the septal nucleus of the embryonic day 16 (E16) rat were grown in culture with a plane of astrocytes from the embryonic rat and in a defined medium in the absence of serum. Neurons were treated with beta-amyloid (Aβ: 0
The senile plaques of Alzheimer's disease contain a high concentration of beta-amyloid (betaA) protein, which may affect the glial population in the septal nucleus, an area of increased risk in AD. BetaA toxicity was measured in septal glia, via a dose-response experiment, by quantifying the effects of three different doses (0.1, 1, and 10 microM) of betaA on cell survival. Astrocytes from embryonic day-16 rats were grown in serum-free media in a single layer culture. Cells were treated on day in vitro (DIV)1 and survival was determined on DIV3 to ascertain which concentration was most toxic. In a separate set of experiments, an attempt was made to protect glial cells from the degenerative effects of betaA, with treatments of growth factors and estrogen. BetaA (10 microM) treatment was administered on DIV1, on DIV2 the cells were treated with estrogen (EST, 10 nM), insulin-like growth factors (IGF1 and IGF2, each 10 ng/ml), basic fibroblast growth factor (bFGF, 5 ng/ml) or nerve growth factor (NGF, 100 ng/ml), and on DIV3 the cells were visualized and quantified by fluorescence microscopy with DAPI (4,6-diamidino-2-phenylindole). In addition to dose-response and glial protection, experiments were also conducted to determine whether toxic effects were due to apoptosis. Our results suggest that the survival of glial populations is significantly affected in all three concentrations (0.1, 1.0, and 10 microM) of betaA. Glial protection was evident in the presence of NGF, for it showed the significantly highest survival rate relative to the betaA treatment alone. Furthermore, toxic effects of betaA appear to be due primarily to apoptosis. Significant reversal of betaA-induced apoptosis was seen with bFGF and IGF1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.