通过构建妊娠合并糖尿病诱发先天性神经管缺陷的SD大鼠模型, 与胚胎不伴有先天性神经管缺陷组大鼠和正常对照组大鼠胚胎进行研究, 提取卵黄囊细胞的mRNA, cDNA 基因芯片技术对表达差异基因进行检测, 应用特异性抗磷酸化抗体进行免疫共沉淀及Western blotting, 对卵黄囊细胞MAP Kinase信号途径蛋白激酶活性进行分析。在神经管缺陷大鼠胚胎卵黄囊细胞和对照组1 200个基因中, 共筛选出表达差异基因79个, 其中42个基因表达上调、37个基因表达下调。同时发现神经管缺陷胚胎卵黄囊细胞出现细胞凋亡特征性的DNA ladder(梯状电泳), 凋亡相关基因 caspase-3、Bax 高表达, 凋亡抑制基因 AKT活性明显受抑; 与正常对照组相比ERK1/2蛋白激酶活性显著下降、JNK1/2活性明显升高。因此, 认为妊娠合并糖尿病诱发胚胎先天性神经管缺陷的发生存在多种差异基因表达, 以及MAP Kinase、凋亡信号传导机制的共同作用。
Abstract: To determine molecular mechanism in hyperglycemia induced congenital neural tube defects, yolk sac cells were harvested at gestational day 12 from streptozotocin (STZ) -induced diabetic rats with congenital neural tube defects in offspring, STZ-induced diabetic rats without neural tube defects and normal control group. We analyzed gene expression profiles in yolk sac cells using a DNA microarray technique. Changes in apoptotic and MAP Kinase signaling pathways were detected by Western blotting analyses. Comparison of genes in yolk sac cells with a total of 1 200 genes in the control cells, 79 genes differently expressed between the two groups were detected. Forty-two of them were up-regulated and 37 were down-regulated. There was strong characteristic apoptotic DNA ladder in yolk sac cells in embryopathic offspring from experimentally-induced diabetic rats. The activity of ERK1/2 was dramatically decreased and the activity of JNK1/2 was significantly increased. Differentially expressed genes, MAP Kinase, and apoptotic signal pathways play very impor-tant roles in hyperglycemia induced neural tube defects. We hope that these could provide useful hallmark to rapid identifi-cation of early diabetic embryopathy.
