小鼠创伤性脑损伤后微小RNA-124变化及其与轴突再生的关系  

Expression change of microRNA-124 and its correlation with axon regeneration after traumatic brain injury in mice

作　　者：苏鑫洪 叶玉勤[1] 贺晓生[1] 

机构地区：[1]第四军医大学西京医院神经外科,西安710032

出　　处：《中华创伤杂志》2017年第1期82-87,共6页Chinese Journal of Trauma

基　　金：国家自然科学基金（81471264）

摘　　要：目的探讨小鼠创伤性脑损伤（TBI）后微小RNA-124（miRNA-124）的表达变化及其与轴突再生的关系。方法将91只C57BL／6小鼠按随机数字表法分为TBI组63只和对照组28只。TBI组制作控制性脑皮质撞击伤模型，分别于TBI后12h、1，3，7，14，21，28d处死，取损伤区脑组织用于实验；对照组仅去骨窗，不予撞击损伤。分别采用HE染色进行损伤区观察，实时PCR检测miRNA-124的表达变化，Western blot和免疫组织化学染色检测轴突标志物神经纤毛蛋白1（Nrp-1）、生长相关蛋白43（GAP-43）、微管相关蛋白（Tau）的表达水平。结果通过对TBI组小鼠行为及HE染色结果的观察，表明造模成功。通过PCR法测得miRNA-124的相对表达量在伤后3d达到高峰（3．80±0．22），Western blot法测得Nrp-1相对表达量在伤后3d达到高峰（2．006±0．179），Tau在伤后14d表达量达到高峰（2．063±0．172），Gap-43在伤后12h即持续高表达（1．355±0．093）（P〈0．05）。创伤后由于直接损伤作用和损伤区水肿，轴突标志物阳性细胞数量在1d时最少，之后缓慢恢复，14，21和28d时数量达到TBI前水平，但形态较对照组发生明显改变。虽然TBI后1d损伤区轴突标志物阳性细胞数量减少，但此时，miRNA-124和Nrp-1、Tau、Gap-43表达量均较对照组有显著升高（P〈0．05）。结论小鼠TBI后损伤区miRNA-124的表达增加可能与轴突再生有密切联系。Objective To observe the expression changes of microRNA-124（miRNA-124） following traumatic brain injury （TBI） in mice and investigate the correlation of miRNA-124 with neural axon regeneration. Methods Ninety-one C57BL/6 mice were assigned into TBI group （n = 63） and control group （n = 28） according to the random number table. Mice in TBI group were subjected to controlled cortical impact and euthanized at 12 hours and 1, 3, 7, 14, 21, 28 days postinjury for the collection of brain tissue in the trauma zone. Mice in control group underwent craniectomy only. Trauma zone observation was done using the HE staining. Expression of miRNA-124 was detected using the real-time PCR. Levels of Nrp-1, Gap-43 and Tau were detected using the Western blot and immunohistochemical staining. Results After injury, study of mice behavior and HE staining indicated the establishment of experimental model was successful. Expression of miRNA-124 reached the peak at 3 days pestinjury （ 3.80 ±0.22）, expression of Nrp-1 reached the peak at 7 days postinjury （ 2.006 ±0. 179 ）, expression of Tau reached the peak at 14 days postinjury （2. 063 ±0. 172）, and expression of Gap-43 sustained high level since 12 hours after injury（ 1. 355 ±0. 093 ） （ P 〈 0.05 ）. Count of axon marker positive cells in TBI group was the lowest at 1 day postinjury due to the direct damage and edema, and then slowly recovered. There was no significant difference in the count of axon marker positive cells between the two groups at 14, 21 and 28 days postinjury （P 〉 0.05）, but the morphology in TBI group changed obviously.Although the positive cells of axon marker decreased at 1 day postinjury, expressions of miRNA-124, Nrp-1, Tan and Gap-43 in TBI group were significantly increased compared to the detections in control group （ P 〈 0.05 ）. Conclusion Increased expression of miRNA-124 in trauma zone may closely related to axon regeneration after TBI in mice.

关 键 词：脑损伤 轴突 微小核糖核酸-124 

分 类 号：R651.15[医药卫生—外科学]