Assis-Nascimento Poincyane, Jarvis Karen M, Montague Jeremy R, Mudd Laura M
School of Natural and Health Sciences, Barry University, 11300 NE 2nd Ave, Miami Shores, FL 33161, USA.
Neurochem Res. 2007 Sep;32(9):1476-82. doi: 10.1007/s11064-007-9335-8. Epub 2007 Apr 4.
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.
阿尔茨海默病的老年斑含有高浓度的β-淀粉样蛋白（βA），这可能会影响隔核中的神经胶质细胞群，而隔核是阿尔茨海默病风险增加的区域。通过剂量反应实验，通过量化三种不同剂量（0.1、1和10微摩尔）的βA对细胞存活的影响，来测定隔核神经胶质细胞中的βA毒性。来自胚胎第16天大鼠的星形胶质细胞在无血清培养基中单层培养。在体外培养第1天对细胞进行处理，并在第3天测定细胞存活率，以确定哪种浓度毒性最大。在另一组实验中，尝试用生长因子和雌激素处理来保护神经胶质细胞免受βA的退行性影响。在体外培养第1天给予βA（10微摩尔）处理，在第2天用雌激素（EST，10纳摩尔）、胰岛素样生长因子（IGF1和IGF2，各10纳克/毫升）、碱性成纤维细胞生长因子（bFGF，5纳克/毫升）或神经生长因子（NGF，100纳克/毫升）处理细胞，在第3天用4,6-二脒基-2-苯基吲哚（DAPI）通过荧光显微镜对细胞进行观察和定量。除了剂量反应和神经胶质细胞保护实验外，还进行了实验以确定毒性作用是否是由细胞凋亡引起的。我们的结果表明，所有三种浓度（0.1、1.0和10微摩尔）的βA都对神经胶质细胞群的存活有显著影响。在NGF存在的情况下，神经胶质细胞保护作用明显，因为相对于单独的βA处理，其显示出显著更高的存活率。此外，βA的毒性作用似乎主要是由细胞凋亡引起的。bFGF和IGF1可显著逆转βA诱导的细胞凋亡。
