Embryonic Gene Expression During Diabetic Embryopathy

项目摘要：糖尿病胚胎病变是一种糖尿病并发症，在这种并发症中母亲的早期胚胎 患有糖尿病的人会发展成先天性畸形。拟议的实验使用了一种小鼠模型 糖尿病妊娠中控制必要发育过程的基因的表达 很不安。这些实验的重点是Pax3，一种在胚胎中表达显著降低的基因 糖尿病小鼠，它编码一种转录因子，这种转录因子是发育结构所必需的，通常 糖尿病胚胎病变时的畸形，尤指神经管和心脏。在之前的资助中 期间，我们发现，母亲的高血糖增加了葡萄糖向胚胎的输送，而氧化 糖代谢过度引起的低氧应激会导致Pax3的表达受损，从而 导致神经管缺陷(NTD)。除了用胚胎进行实验外，我们还用小鼠 胚胎干细胞(ES细胞)，可大量生长并可诱导为表达Pax3的细胞 神经上皮细胞类型。 在这项提议中要检验的中心假设是， 早期胚胎的葡萄糖代谢导致氧化和低氧应激，从而阻止了诱导 或激活基本发育控制基因表达的转录因子的结合。在这 我们将：(1)研究低氧应激、氧化应激和蛋白质增加之间的相互作用。 激酶C活性导致Pax3表达受损；(2)确定与Pax3调节因子结合的因素 分化诱导表达所需且受氧化应激抑制的元件；以及 (3)检验这样一个假设，即导致Pax3表达受损的相同生化紊乱 小鼠ES细胞也导致人ES细胞PAX3表达受损。 相关性：了解母体糖尿病如何从生化角度干扰早期胚胎发育 而分子水平是至关重要的，以便制定新的策略来预防它们。拟议的研究 将使用糖尿病妊娠小鼠模型和小鼠胚胎干细胞来阐明生化 重要胚胎基因表达受干扰的机制和人类胚胎干细胞 为了确定小鼠和小鼠干细胞在多大程度上充当影响的模型 人类糖尿病妊娠期间的生化紊乱。

Project Summary: Diabetic embryopathy is a diabetic complication in which the early embryo of a mother with diabetes develops congenital malformations. The proposed experiments employ a mouse model of diabetic pregnancy in which expression of genes which control essential developmental processes is disturbed. These experiments focus on Pax3, a gene whose expression is significantly reduced in embryos of diabetic mice, which encodes a transcription factor required for development of structures that are often malformed during diabetic embryopathy, especially the neural tube and the heart. In the previous funding period, we showed that maternal hyperglycemia increases glucose delivery to the embryo, and that oxidative and hypoxic stress, resulting from excess glucose metabolism, causes impaired Pax3 expression, thereby leading to neural tube defects (NTD). In addition to experiments using embryos, we have used murine embryonic stem (ES) cells, which can be grown in quantity and can be induced to a Pax3-expressing neuroepithelial cell type. The central hypothesis to be tested in this proposal is that biochemical pathways affected by increased glucose metabolism by the early embryo causes oxidative and hypoxic stress, which prevents the induction or binding of transcription factors that activate expression of essential developmental control genes. In this proposal we will: (1) Investigate the interaction of hypoxic stress, oxidative stress, and increased protein kinase C activity leading to impaired Pax3 expression; (2) Identify factors which bind to a Pax3 regulatory element that is needed for differentiation-induced expression and which is inhibited by oxidative stress; and (3) Test the hypothesis that the same biochemical disturbances that lead to impaired Pax3 expression in mouse ES cells also lead to impaired PAX3 expression in human ES cells. Relevance: Understanding how maternal diabetes disturbs early embryonic development on a biochemical and molecular level is essential in order to devise new strategies to prevent them. The proposed research will use a mouse model of diabetic pregnancy and mouse embryonic stem cells to elucidate the biochemical mechanisms by which important embryonic gene expression is disturbed, and human embryonic stem cells to determine the extent to which the mouse and mouse stem cells serve as a model for the effects of biochemical disturbances during human diabetic pregnancy.