Chen Ying, Cao Shuyan, Xu Pingping, Han Wei, Shan Tiankai, Pan Jingying, Lin Weiwei, Chen Xue, Wang Xiaodong
Department of Histology and Embryology, Medical College, Nantong University, Nantong, Jiangsu, China (mainland).
Department of Pathology, Lishui Hospital of Zhejiang University, Lishui, Zhejiang, China (mainland).
Med Sci Monit. 2016 Oct 25;22:3981-3993. doi: 10.12659/msm.900893.
BACKGROUND Results from DNA microarray experiments have shown that the expression of miR-34s undergoes significant changes following spinal cord injury (SCI). The present study was designed to detect changes in the expression of miR-34s and its target genes during the acute and sub-acute stages of SCI. MATERIAL AND METHODS Luxol fast blue (LFB) staining for myelin was used to observe the differences in the general morphology of the spinal cord after SCI in a contusion model in rats. qPCR was carried out to determine the expression variation of miR-34s and its target genes during the acute and sub-acute stages of SCI. The mimic technique was used to further confirm the regulatory effect of miR-34a on the potential target genes. RESULTS The expression level of miR-34a decreased immediately after SCI and persisted for 21 days after SCI. The expression level of miR-34c began decreasing at day 1 after SCI and persisted until day 14. The expression level of miR-34b did not undergo significant change after SCI. The results of double immunofluorescence and in-situ hybridization suggested that miR-34a was highly expressed in spinal cord neurons. Based on our bioinformatics analysis, we postulated that miR-34a might participate in post-SCI cell apoptosis by regulating the target gene Notch1, and likely participated in the inflammatory response and glial scar formation by regulating the candidate genes Csf1r and PDGFRa, respectively. The expression levels of the candidate genes Csf1r and PDGFRa were consistent with Notch1 after SCI. The mimic technique further confirmed the regulatory effect of miR-34a on the aforementioned target genes. CONCLUSIONS We postulate that miR-34a and miR-34c might participate in multiple aspects of cytobiological activities following SCI. MiR-34a in particular may participate in cell apoptosis, inflammatory response, and glial scar formation by regulating the target gene Notch1 and candidate target genes Csf1r and PDGFRa respectively.
DNA微阵列实验结果表明，脊髓损伤（SCI）后miR-34s的表达发生显著变化。本研究旨在检测SCI急性和亚急性阶段miR-34s及其靶基因的表达变化。
采用Luxol固蓝（LFB）髓鞘染色法观察大鼠挫伤模型中SCI后脊髓的大体形态差异。进行qPCR以确定SCI急性和亚急性阶段miR-34s及其靶基因的表达变化。采用模拟技术进一步证实miR-34a对潜在靶基因的调控作用。
miR-34a的表达水平在SCI后立即下降，并在SCI后持续21天。miR-34c的表达水平在SCI后第1天开始下降，并持续至第14天。miR-34b的表达水平在SCI后未发生显著变化。双重免疫荧光和原位杂交结果表明，miR-34a在脊髓神经元中高表达。基于我们的生物信息学分析，我们推测miR-34a可能通过调节靶基因Notch1参与SCI后的细胞凋亡，并可能分别通过调节候选基因Csf1r和PDGFRa参与炎症反应和胶质瘢痕形成。SCI后候选基因Csf1r和PDGFRa的表达水平与Notch1一致。模拟技术进一步证实了miR-34a对上述靶基因的调控作用。
我们推测miR-34a和miR-34c可能参与SCI后的多种细胞生物学活动。特别是miR-34a可能分别通过调节靶基因Notch1和候选靶基因Csf1r和PDGFRa参与细胞凋亡、炎症反应和胶质瘢痕形成。
