Wnt/PCP-JNK信号通路在NTDs发生及牛磺酸预防NTDs的介导作用

Neural tube defects(NTDs) is a severe congenital abnormality of central nervous system,which is highly prevalent in minority areas of Ningxia. Research shows that Wnt-PCP and MAPK-JNK paths are closely related to cell convergent extension and cell apoptosis during nervous system development.They play an important role in NTDs happening and RhoA between the two paths works as the connection.Taurine promotes growth and development of nervous system and cell proliferation and differentiation. Experimental results show Wnt/PCP-JNK path plays the role of mediation during the protection on nervous system by taurine.The experiment(1)builds NTDs model and taurine intervention model through animal experiment and cell culture in vitro,and comprehensively analyzes the mechanism of action of Wnt/PCP-JNK on NTDs happening and preventing NTDs with taurine.(2)The experiment adopts siRNA interference technology based on cell culture in vitro,and sets up gene silence groups for proteins Dvl and RhoA in paths,to intensively study the mediation mechanism of the path on preventing NTDs with taurine.

神经管畸形(Neural tube defects,NTDs)是严重的中枢神经系统先天性畸形，宁夏少数民族地区是该疾病的高发地区。研究表明Wnt-PC和MAPK-JNK通路和神经系统发育中细胞的汇聚延伸和细胞凋亡密切相关，在NTDs发生中均起到重要作用，而且两通路之间RhoA起到了联系两通路的作用。牛磺酸促进神经系统的生长发育和细胞增殖、分化，实验证明Wnt/PCP-JNK通路在牛磺酸对神经系统的保护作用起到介导作用，本实验(1)通过动物实验及体外细胞培养建立NTDs的模型及牛磺酸干预模型，免疫荧光、western等技术综合分析Wnt/PCP-JNK通路在NTDs发生中及牛磺酸预防NTDs的作用机制。(2)本实验在体外细胞培养的基础上采用siRNA干扰技术，分别对通路中调节蛋白Dvl和RhoA设立基因沉默组，深入研究该通路对牛磺酸预防NTDs的介导机制。

本研究的目的是阐明牛磺酸在神经细胞凋亡中的保护作用及Wnt/PCP-Jnk通路介导牛磺酸预防神经管畸形(NTDs)的作用。HT-22细胞(海马神经元细胞系)被分为对照组、谷氨酸诱导凋亡组和谷氨酸(4.0 mmol/L) +低剂量牛磺酸(0.5 mmol/L)，高剂量牛磺酸(2.0 mmol/ L)组，MTT法检测细胞增殖和细胞存活，采用免疫荧光法和Western blot法测定caspase 9的表达。维甲酸(RA)诱导昆明小鼠胚胎NTDs，建立NTD模型。孕鼠被分为对照组、RA(30 mg/kg)组和 RA (30 mg/kg)+牛磺酸(2 g/L自来水)，采用免疫组织化学和Western blot方法检测胚胎神经管中Dvl、RhoA和磷酸化(p)-Jnk/Jnk的表达。在HT-22细胞中，与低剂量牛磺酸及高剂量牛磺酸组相比，谷氨酸诱导的细胞凋亡组细胞凋亡率明显升高，caspase 9表达也明显增加。在NTD模型中，RA组的Dvl、RhoA和p-Jnk的表达水平明显高于对照组，而RA + taurine组的表达水平明显降低。本研究提示牛磺酸对神经保护和NTD预防的作用。此外，Wnt/PCP-Jnk通路在介导牛磺酸预防NTDs中发挥重要作用。此结论为神经管畸形的发生诊治提供重要的理论基础。