（ 1、华中科技大学同济医学院法医学系，武汉 430030； 2、华中科技大学 同济医学院法医学系 湖北武汉 430030； ）
摘要： 目的 应用微阵列基因芯片技术检测创伤性脑损伤大鼠伤后1天、3天、5天的大脑海马microRNA表达变化,分析差异表达的海马microRNA对脑损伤后认知功能障碍的可能作用机制。方法 SD大鼠行大脑单侧控制性皮层撞击损伤建立创伤性脑损伤动物模型（速度4米/秒，持续150毫秒，打击深度3毫米）。在伤后1天、3天、5天处死大鼠分离致伤侧大脑海马组织，应用基因芯片技术分析海马microRNA的表达情况。结果 由基因芯片分析得到分层聚类图，与对照组相比，在205个microRNA中，伤后1d组有41个microRNA表达上调1.5倍以上，31个microRNA表达下调1.5倍以上；伤后3d组有81个microRNA表达上调1.5倍以上，11个microRNA表达下调1.5倍以上；伤后5d组有52个microRNA表达上调1.5倍以上，41个microRNA表达下调1.5倍以上。共有17个microRNA在三个损伤时间点均出现差异性表达，其中miR-142-3p和miR-221可能在脑损伤的病理生理学过程中起到关键作用。结论 伤后不同时间点大鼠海马microRNA的表达具有不同时序性，推测其在海马应对颅脑损伤的过程中发挥着特定作用。其中，miR-142-3p和miR-221有可能作为潜在的生物学标记物在临床法医学上用以评估创伤性脑损伤，并为损伤相关的认知功能障碍奠定实验研究基础。
SUN Tingyi1,， LIU Zilong2,*， LIU Liang2,， CHEN Xiaorui2,， ZHAO Lili2,， QU Guoqiang2,
（ 1、Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, WuHan 430030； 2、Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030； ）
Abstract： Objectives To descript the changes in expression of microRNAs in the hippocampus of rats at 1 day, 3 days and 5 days following traumatic brain injury (TBI) by microarray technique, and investigate the possible cellular activities that are regulated by microRNAs which differentially expressed in the hippocampus, that may contribute to TBI-induced cognitive impairment. Methods Adult SD rats received a single controlled cortical impact (CCI) injury using an electromagnetic piston at a velocity of 4 m/sec, duration of 150 ms and depth of 3 mm. The ipsilateral hippocampus was harvested for the subsequent microarray assays at three time points post-injury: 1 day, 3 days and 5 days, respectively. We characterize the microRNA expression profile in rat hippocampus compared with sham group using the Significance Analysis of Microarrays analysis. Results We got a dendrogram of a Hierarchical Clustering analysis of the result. Totally 205 microRNAs were identified which were up-/down-regulated more than 1.5 times. At 1 d post-injury, 41 microRNAs were up-regulated more than 1.5 times, and 31 microRNAs were down-regulated more than 1.5 times; at 3 d post-injury, 81 microRNAs were up-regulated more than 1.5 times, and 11 microRNA s were down-regulated more than 1.5 times; at 5 d post-injury, 52 microRNAs were up-regulated more than 1.5 times, and 41 microRNAs were down-regulated more than 1.5 times. Furthermore, we revealed 17 microRNAs which were changed at all three time points post-injury, the notable two microRNAs were miR-142-3p and miR-221, which could involve in many pathophysiological processes. Conclusions Our microarray-based bioinformatics analysis has showed that microRNAs in rat hippocampus have different expression levels at various time points post-injury, suggesting it is likely an active approach for cells to cope with injury through modulating microRNA expression, and microRNAs play key roles in the pathological courses after injury and work collaboratively like a complicated gene expression network. MiR-142-3p and miR-221 may be used as potentially biological markers for TBI assessment, and thus make some improvements in exploratory research for TBI-related cognitive disorder.
Keywords： forensic clinical medicine; microRNA; microarray; hippocampus; traumatic brain injury
作者简介： SUN Tingyi,(1985-), female, PhD, forensic pathology and clinical forensic medicine （孙婷怡，1985-，女，博士研究生，研究方向为法医病理学和法医临床学 ）
通信联系人： LIU Zilong (1976-), male, PhD, Lectuer, clinical forensic medicine；（刘子龙，1976-，男，博士，讲师，研究方向为临床法医学）