In vitro ischemia triggers a transcriptional response to down-regulate synaptic proteins in hippocampal neurons.

The present study has used whole-rat genome microarray expression profiling to identify genes whose expression is significantly altered in hippocampal neuronal cultures submitted to oxygen and glucose deprivation (OGD), an established in vitro model for cerebral global ischemia that is suitable for investigations at the molecular level. To do so, total RNA was extracted from hippocampal neuronal cultures at an early (7h) and delayed (24h) time point after OGD, as well as from control neurons. Analysis of gene ontology showed that OGD followed by 7h or 24h of recovery induces changes in the expression levels of genes related with inflammation, response to oxidative stress, metabolism, apoptosis, synaptic proteins and ion channels and, importantly, genes that show different expression levels are mainly specific to one of the two time points of recovery analyzed. The expression levels of several genes were confirmed by qPCR and were in good agreement with the microarray data, showing that the combined use of the OGD model and the microarray technology can be a useful tool for the study molecular mechanisms contributing to the neuronal demise after transient global ischemia.本研究采用全大鼠基因组微阵列表达谱分析，旨在筛选经氧糖剥夺（oxygen and glucose deprivation, OGD）处理的海马神经元培养物中表达发生显著改变的基因；氧糖剥夺是一种已确立的全脑缺血体外模型，可用于分子水平的相关研究。为完成该分析，研究人员分别在氧糖剥夺处理后的早期（7小时）与延迟（24小时）两个时间点，以及对照组神经元中提取总RNA。基因本体论分析结果显示，经氧糖剥夺并恢复7小时或24小时后，与炎症反应、氧化应激应答、细胞代谢、细胞凋亡、突触蛋白及离子通道相关的基因表达水平发生改变；尤为重要的是，在两个分析的恢复时间点中，差异表达基因大多具有时间特异性。本研究通过定量聚合酶链反应（qPCR）验证了部分基因的表达水平，其结果与微阵列数据一致性良好，这表明将氧糖剥夺模型与微阵列技术联合使用，可作为研究暂时性全脑缺血后神经元死亡相关分子机制的有效工具。