SEARCH FOR THE MOLECULAR CAUSES OF DIABETIC EMBRYOPATHY

糖尿病胚胎病是一种公认的，但知之甚少， 糖尿病并发症的早期胚胎糖尿病的方法 会出现先天性畸形此处提出的工作目标 是研究糖尿病对一个重要的发育控制的调节， 基因，Pax-3，在最常见的糖尿病之一的发展过程中， 相关畸形，神经管缺陷（NTD）。使用新鼠标 在我的实验室开发的模型中，我们观察到， NTD在糖尿病小鼠胚胎中的含量比在正常小鼠胚胎中高出约3倍。 非糖尿病小鼠的胚胎。NTD的高发生率与 Pax-3的表达减少，Pax-3是一种编码DNA结合的胚胎基因， 转录因子，其是形成大脑所必需的， 脊髓在Pax-3表达减少之后， 很明显，形成神经管的细胞 进行非程序性凋亡。 这项建议有三个具体目标。在第一个目标中，我们将 检验葡萄糖毒性与母体 糖尿病是胚胎基因表达异常的原因， 凋亡和NTD。这将通过以下方式实现：（1）努力防止 通过降低妊娠糖尿病小鼠的葡萄糖水平， 胰岛素或根皮苷给药，（2）试图诱导葡萄糖 通过高血糖葡萄糖钳夹对妊娠非糖尿病小鼠的毒性 （3）在培养过程中试图诱导葡萄糖毒性， 实施后小鼠胚胎在含有高水平的 （4）检测高Km GLUT-2葡萄糖的表达 转运蛋白使早期胚胎对葡萄糖毒性敏感， 糖尿病妊娠在第二个目标中，我们将确定 在糖尿病和非糖尿病胚胎中观察到Pax-3 mRNA的减少 小鼠是由于转录或转录后控制，和 确定参与糖尿病抑制的Pax-3控制元件。在 第三个目标，我们将测试的假设，小鼠品系失败， 在糖尿病妊娠期间发生NTD的人对抑制有抵抗力， Pax-3的表达，这发生在对NTD敏感的菌株中。 这些实验将揭示，在某种程度上，还没有这样做， 过去，胚胎发育过程中的分子机制 糖尿病妊娠

Diabetic embryopathy is a well recognized, but poorly understood, complication of diabetes in which the early embryo of a diabetic method develops congenital malformations. The objective of the work proposed here is to study the regulation by diabetes of a critical development control gene, Pax-3, during the development of one of the most common diabetes- associated malformations, neural tube defects (NTD). Using a new mouse model that was developed in my laboratory, we have observed that the rate of NTD is about three-fold higher in the embryos of diabetic mice than in the embryos of non-diabetic mice. The high rate of NTD is correlated with reduced expression of Pax-3, an embryonic gene which encodes a DNA-binding transcription factor that is required for formation of the brain and spinal chord. Subsequent to the reduction in expression of Pax-3, and apparently as a consequence, cells forming the neural tube are seen to undergo unscheduled apoptosis. There are three specific aims of this proposal. In the first aim, we will test the hypothesis that glucose toxicity associated with maternal diabetes is responsible for abnormalities in embryonic gene expression, apoptosis, and NTD. This will be accomplished by (1) attempting to prevent glucose toxicity by lowering glucose levels in pregnant diabetic mice with insulin or phlorizin administration, (2) attempting to induce glucose toxicity in pregnant non-diabetic mice by a hyperglycemic glucose clamp procedure, (3) attempting to induce glucose toxicity during culture of post-implementation mouse embryos in media containing elevated levels of glucose, and (4) testing whether expression of the high Km GLUT-2 glucose transporter renders the early embryos sensitive to glucose toxicity during diabetic pregnancy. In the second aim, we will determine whether the reduction in Pax-3 mRNA observed in embryos of diabetic and non-diabetic mice is due to transcriptional or post-transcriptional control, and identify the Pax-3 control elements involved in inhibition by diabetes. In the third aim, we will test the hypothesis that mouse strains which fail to develop NTD during diabetic pregnancy are resistant to the inhibition of Pax-3 expression that occurs in strains which are susceptible to NTD. These experiments will reveal, in a way that has not been done in the past, the molecular mechanisms by which embryonic development is during diabetic pregnancy.