创伤性脑损伤大鼠P300检测与海马microRNA表达变化

目的探讨创伤性脑损伤后大鼠海马microRNA的表达变化与认知功能障碍的相关性。方法 25只SD大鼠随机分为假手术组和伤后1h、1d、3d、5d组,采用Feeney自由落体法建立创伤性脑损伤动物模型。各组大鼠于设定的损伤时间点检测事件相关电位P300,应用基因芯片技术检测海马microRNA的表达情况,筛选特异性表达的microRNA。结果各组大鼠伤后P300的潜伏期延长,波幅下降,以伤后1d为甚。与假手术组相比,伤后各实验组microRNA表达谱具有显著差异。其中miR-21、miR-16、let-7b的表达与P300潜伏期变化存在显著相关,伤后1d为差异性表达的关键时间点。结论 microRNA可能在创伤性脑损伤后发生的认知功能障碍中发挥调控作用,有望为脑损伤后认知功能的法医学鉴定提供新的思路。

The relationship between microRNA profiling of rat hippocampus and the P300 event-related potential following traumatic brain injury

Objective To explore the correlation between microRNA profiling of rat hippocampus and cognitive function disorder with traumatic brain injury. Methods Totally 25 SD rats were randomly divided into sham-operated group and experimental group including l h group, l d group, 3d group and 5d group. The brain injury groups were prepared by improved Feeney＇s free falling method. The event-related potential P300 was examined at each injury time point. We characterize the microRNA expression profile in rat hippocampus using the microarrays analysis, and screen differentially expressed specific microRNAs. Results The latencies were significantly prolonged and the amplitudes were reduced in experimental groups compared with that of P300 in sham group, which the latency reached its max value at 1 day post injury. Through comparison between TBI groups and sham-operated group, the mieroRNA microarray analysis results indicated that up-or down- regulation of the differentially-expressed microRNAs in the injured hippocampus are detected at different injury time point post-TBI. The notable three microRNAs were miR-21, miR-16 and let-Tb, which were significantly correlated with P300 latency. Conclusion MicroRNAs may play regulatory roles in cognitive disorder after injury, and thus make some improvements in forensic identification for TBI-related cognitive disorder.