高胆固醇对Aβ诱导神经元损伤和胶质细胞活化的影响

Effect of high cholesterol on Aβ-induced injury of neurons and activation of glial cell

目的探讨高胆固醇对Aβ诱导体外培养神经元损伤和胶质细胞活化的作用。方法混合培养的海马神经元和胶质细胞随机分为3组:正常对照组、Aβ组(2μmol/L)和高胆固醇组(1mmol/L)+Aβ组(2μmol/L);检测细胞培养上清液中LDH释放度;免疫荧光检测神经元形态改变;ELISA检测细胞培养上清液中IL-6和TNF-α的含量。结果高胆固醇+Aβ组LDH释放度(33.2±3.5)显著高于Aβ组(28.1±2.4),差异有统计学意义;高胆固醇+Aβ组神经元数目减少,神经突起断裂,突起回缩均较Aβ组明显;高胆固醇+Aβ组上清液中IL-6和TNF-α含量(29.6±5.2,42.6±5.1)最高,与Aβ组(20.8±4.6,35.5±3.6)相比差异有统计学意义。结论高胆固醇增强Aβ诱导胶质细胞活化IL-6和TNF-α表达可能是高胆固醇加重Aβ诱导神经元损伤的机制。

Objective To study the effect of high cholesterol on Aβ-induced injury of neurons and activation of glial cell in vitro. Methods The mixed cultured hippocampal neurons and glial cell were divided into three groups, control group, Aβgroup （2μmol/ L）, high cholesterol（lmmol/L） ＋ Aβ（2μmol/L） group ; Lactic dehydrogenase （LDH） releasing assay was applied for measurement of injury of the neuron cell; morphous of the neurons was subjected to fluorescence staining;IL-6 and TNF-α contents in culture supernatants were determined by ELISA. Results Percent of LDH release in hippocampal culture of cholesterol＋Aβ group （33.2±3. 5） was larger than Aβgroup （28.1 ± 2.4）. CH＋Aβ group had fewer neurons and shorter nerve process than Aβ group. IL-6 and TNF-α contents of CH＋Aβgroup （29.6±5.2,42.6±5.1） were the highest in all groups, the differences in IL-6 and TNF-α contents were significant between CH＋Aβ group and Aβgroup. Conclusion High cholesterol enhances activation of glial cells and expression of IL-6 and TNF-ainduced by Aβ, which is possible mechanism that aggravate Aβ-induced injury of neurons.