电针刺激P53/miRNA-34a轴调控脊髓神经干细胞分化治疗脊髓损伤的作用机制

The high incidence of spinal cord injury(SCI) to patients and the community caused a heavy burden, there is no recognized effective cure, electroacupuncture treatment of spinal cord injury has a good effect, but its mechanism of action is not yet clear. Previous studies have shown that electroacupuncture at Dazhui and Mingmen two acupoints can regulate the expression of P53 in the spinal cord. MiRNA-34a,the direct target of P53, can regulate the differentiation of neural stem cells, and the acupuncture stimulation of p53 / miRNA-34a axis may regulate the differentiation of neural stem cells, this may be the important electroacupuncture mechanism for SCI. In this study, we investigated the mechanism study of stimulation effect of electroacupuncture on neural stem cell dedifferentiation through p53/miRNA-34a axis for the treatment of SCI by vivo and vitro experiments, use methods including evaluations for cell proliferation, apoptosis and inflammatory response,changes of spinal cord microenvironment, as well as behavioral evaluation.

脊髓损伤发病率高，给患者及社会造成了沉重的负担，目前尚无公认的有效治愈办法，中医电针治疗脊髓损伤具有较好的疗效，但其作用机制尚不明了。既往研究表明，电针督脉大椎、命门两穴能调控脊髓P53的表达，P53的直接靶点miRNA-34a能调控神经干细胞分化，电针刺激p53/miRNA-34a轴调控脊髓神经干细胞分化可能是电针治疗脊髓损伤的重要机制。本研究通过体内、外实验，采用行为学评价，分子生物学以及细胞生物学等研究方法，研究电针刺激p53/miRNA-34a轴影响细胞增殖、凋亡和炎症反应等，改善脊髓微环境，直接或间接调控神经干细胞分化以治疗脊髓损伤，促进脊髓功能恢复的作用机制。

脊髓损伤是临床难点，也是研究的热点，脊髓损伤后神经干细胞增殖分化为功能神经元是脊髓功能修复的重要内容，电针调控脊髓损伤组织P53表达，miR-34a是神经元正确分化的必需物质，miR-34a受P53靶向调控，阐明电针、P53、miR-34a及神经干细胞分化为功能神经元之间的作用关系可提高电针治疗脊髓损伤作用机制认知。本研究证实：（1）miR-34a-3p与PDCD6特异性结合，负调节PDCD6表达，促进神经干细胞增殖，抑制神经干细胞分化星形胶质细胞，促进神经干细胞分化神经元；（2）电针上调P53/miR-34a-3p轴表达水平，提高脊髓损伤大鼠后肢运动功能BBB评分；（3）EA通过上调miR-34a-3p负调节PDCD6表达促进神经干细胞增殖，抑制神经干细胞向星形胶质细胞分化，促进轴突再生和髓鞘形成，促使神经干细胞向功能神经元方向分化；（4）NF-B1/LINC00665/miR-34a-5p与SCI关系密切，可能是SCI的治疗靶点，为后续EA治疗SCI作用机制研究提供指导方向。