Plasma miRNAs as biomarkers of epilepsy. Plasma miRNAs as biomarkers of epilepsy

Epilepsy frequently develops as a result of brain insult, for example brain injury or stroke. Currently there are no tools allowing us to predict which trauma patients will eventually develop epilepsy. There is evidence that microRNAs levels are altered in plasma, making them attractive candidates for peripheral biomarkers of epilepsy. We analyzed miRNA levels in plasma samples using Affymetrix microarrays 4.1 and performed comparative analysis of samples. We performed 3 comparisons: i) control animals vs. Status epilepticus animals, ii) animals which developed first spontaneous seizure around 7 days post stimulation (EARLY), or later after 21days post stimulation (LATE), iii) animals that had developed seizures at given timepoint (EPI) and animals that did not experience seizures by given timepoint (NONEPI). Overall design: We draw the blood from rats after electrical stimulation of amygdala, which induces status epilepticus, at 4 timepoints: 14, 30, 60 and 90 days after status epilepticus. Later RNA was isolated from all the samples at the same time and microarray 4.1 were used in agreement with the producer's protocol, to test levels of each miRNA.

癫痫常继发于脑损伤事件，例如颅脑外伤或脑卒中。目前尚无工具可用于预测哪些创伤患者最终会罹患癫痫。已有研究证实，血浆中微小RNA（microRNA）的表达水平会发生改变，使其成为癫痫外周生物标志物的理想候选对象。本研究采用Affymetrix微阵列芯片4.1（Affymetrix microarrays 4.1）对血浆样本中的微小RNA水平进行了检测，并开展了样本对比分析。共设置三组对照：① 对照组动物与癫痫持续状态（Status epilepticus）模型动物；② 刺激后约7天首次出现自发性癫痫发作的动物（早期组，EARLY），以及刺激后21天及以后出现发作的动物（晚期组，LATE）；③ 在指定时间点已出现癫痫发作的动物（癫痫组，EPI）与截至指定时间点未出现发作的动物（非癫痫组，NONEPI）。总体实验设计：本研究通过电刺激大鼠杏仁核以诱导癫痫持续状态，分别于造模后14、30、60、90天四个时间点采集大鼠血液样本。后续统一时间从所有样本中提取RNA，并严格按照生产商的实验方案使用Affymetrix微阵列芯片4.1检测各微小RNA的表达水平。