Chen Lu, Li Xing, Zhu Jianping, Xu Binwu, Gu Yurong
The Second Affiliated Hospital of Nanchang University, No. 1 Minde Road, Nanchang, China.
Arch Med Sci. 2019 Nov 25;19(3):744-756. doi: 10.5114/aoms.2019.90008. eCollection 2023.
Contusion spinal cord injury is involved in a number of cellular, biochemical and molecular changes. We studied the overall expression pattern of miRNAs on day 1 and 3 after spinal cord injury and the involved pathways.
A spinal cord injury model was developed by contusion injury in rats. Microarray analysis and qRT-PCR were done for expression of miRs. The Basso, Beattie and Bresnahan (BBB) locomotor score was determined after spinal injury. Lesions at the injured site were analyzed by cresyl staining. Western blot analysis was carried out to analyze protein levels. Immunohistochemical staining was done to evaluate immunoreactivity. TUNEL assay was performed to determine the number of apoptotic cells.
The microarray analysis data suggested that about eight miRs were upregulated whereas four were downregulated in rats subjected to spinal cord injury on day 1. On comparing sham operated rats from the day 3 group two miRs were overexpressed and four were downregulated. miR-19a was the most deregulated. miR-19a antagomir was used as an inhibitor, which aggravated the functional deficit, decreased the protection of spinal cord tissue and elevated the number of apoptotic cells. The treatment of miR-19a antagomir increased the expression of FasL along with PTEN, but it failed to affect the levels of PDCD4.
The results suggested that miR-19a plays a potential role in halting the neuronal cell death spinal cord injury and that the protective role of miR-19a may be due to its regulatory effect on pro-apoptotic genes.
脊髓挫伤性损伤涉及许多细胞、生化和分子变化。我们研究了脊髓损伤后第1天和第3天微小RNA（miRNA）的整体表达模式及其相关通路。
通过对大鼠进行挫伤建立脊髓损伤模型。对miR的表达进行芯片分析和定量逆转录聚合酶链反应（qRT-PCR）。脊髓损伤后测定巴索、贝蒂和布雷斯纳汉（BBB）运动评分。通过甲酚染色分析损伤部位的病变情况。进行蛋白质印迹分析以分析蛋白质水平。进行免疫组织化学染色以评估免疫反应性。进行末端脱氧核苷酸转移酶介导的缺口末端标记（TUNEL）测定以确定凋亡细胞数量。
芯片分析数据表明，在脊髓损伤第1天的大鼠中，约有8种miR上调，而4种miR下调。与第3天假手术组大鼠相比，有2种miR过表达，4种miR下调。miR-19a的失调最为明显。使用miR-19a拮抗剂作为抑制剂，其加重了功能缺陷，降低了脊髓组织的保护作用并增加了凋亡细胞数量。miR-19a拮抗剂处理增加了FasL以及PTEN的表达，但未影响程序性细胞死亡蛋白4（PDCD4）的水平。
结果表明，miR-19a在阻止脊髓损伤中神经元细胞死亡方面发挥潜在作用，并且miR-19a的保护作用可能归因于其对促凋亡基因的调节作用。
