Craniofacial Morphogenesis in Prenatal Alcohol Exposure

产前酒精暴露中的颅面形态发生

• 批准号: 8134114
• 负责人: SUSAN M. SMITH
• 金额: $ 7.43万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-05 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8134114
• 关键词: Address; Adult; Affect; Alcohols; Apoptosis; Apoptotic; Appearance; Award; Calmodulin; Cardiac; Cell Death; Cells; Cessation of life; Chick Embryo; Colorectal; Consensus; Cranial Nerves; Development; Elements; Embryo; Embryonic Development; Ethanol; Fetal Alcohol Exposure; Fetus; G Protein-Coupled Receptor Genes; GTP-Binding Proteins; Gene Expression; Genetic Transcription; Human; Immunochemistry; Induction of Apoptosis; Investigation; Ligands; Mammals; Mediating; Mediator of activation protein; Mental Retardation; Messenger RNA; Modeling; Morphogenesis; Neural Crest; Neurotoxins; Oncogenes; Parasympathetic Nervous System; Pathway interactions; Pentanols; Phospholipase C; Phosphotransferases; Population; Proteins; RNA Interference; Reporter; Research Personnel; Signal Pathway; Signal Transduction; Small Interfering RNA; Stem cells; Structure; Testing; Time; Tissues; Transfection; Vertebrates; Work; alcohol exposure; alcohol response; blastomere structure; cell growth; cell type; cellular targeting; clinically relevant; craniofacial; embryo/fetus; expression vector; face bone structure; gain of function; genetic manipulation; loss of function; mutant; neuronal survival; novel; programs; research study; transfection/expression vector

DESCRIPTION (provided by applicant): Alcohol is a potent neurotoxicant, and prenatal alcohol exposure is the leading known cause of mental retardation. One affected population is the neural crest. Our past work found that clinically relevant ethanol exposures (20-80 mM) cause neural crest apoptosis; a hitherto unexplained observation is that the timing of this death coincides with the endogenous apoptosis of these cells. Our current award established that ethanol causes an intracellular Ca2+ transient that is necessary and sufficient to cause neural crest apoptosis. This Ca2+ transient originates from ethanol's stimulation of Gai2/3, and Gpy-mediated activation of PI-PLC. We recently discovered that ethanol and its Ca2+ transient rapidly suppress canonical Wnt/p- catenin signals within neural crest; these provide essential trophic support to neural crest and govern their morphogenesis. Conversely, the G protein/PI-PLC/Ca pathway that is activated in neural crest by ethanol converges on a distinct Wnt pathway, known as the non-canonical Wnt/Ca pathway, that uses G protein and PI-PLC-mediated Ca2+ release to repress canonical Wnt signals and cause the endogenous cell death of neural crest. Studies in this competing renewal test the hypothesis that the ethanol-stimulated Ca2+ transient is apoptotic because it suppresses the Wnt/S-catenin signals that provide trophic support to the neural crest. We further propose that the ethanol-induced Ca2+ transient converges on and activates the noncanonical Wnt/Ca signals that similarly repress 3-catenin to cause endogenous neural crest death. Aim 1 tests whether the ethanol-induced Ca2+ transient suppresses the Wnt/(3-catenin signals that govern neural crest development and survival. We will investigate whether the loss of trophic support provided by Wnt/p-catenin contributes to their apoptosis. Aim 2 tests whether ethanol's suppression of Wnt/p-catenin is mediated by calmodulin-dependent kinase II (CaMKII), which converts the Ca2+ transient into a pro-apoptosis cellular signal. Aim 3 tests whether the ethanol-induced Ca2+ transient in neural crest disrupts Wnt/p-catenin and causes apoptosis because it converges on and activates the Wnt/Ca signals that govern the coincident endogenous cell death of neural crest. These studies are a logical extension of the current award. We continue to use our established chick embryo model, which replicates the alcohol responses of mammals including humans, has well-described neural crest development, and is now accessible for genetic manipulation using electroporetic transfection of gain- of-function or siRNA expression vectors. Wnt activities are highly conserved among vertebrates. They are important regulators of cell growth and differentiation in diverse tissues, raising the possibility that Wnts represent a novel target for alcohol action in the fetus and the adult.

描述(申请人提供)：酒精是一种强烈的神经毒物，产前酒精暴露是导致智力低下的主要已知原因。一个受影响的人群是神经脊。我们过去的工作发现，临床上相关的酒精暴露(20-80 mM)会导致神经脊细胞凋亡；一个迄今尚未解释的观察是，这种死亡的时间与这些细胞的内源性凋亡相吻合。我们目前的奖项确定，乙醇导致细胞内钙瞬变，这是必要的，也是足以导致神经脊细胞凋亡的。这种钙瞬变来源于乙醇对Gai2/3的刺激，以及GPY介导的PI-PLC的激活。我们最近发现，乙醇及其钙离子瞬变迅速抑制神经脊内典型的Wnt/p-catenin信号；这些信号为神经脊提供必要的营养支持，并控制其形态发生。相反，被乙醇激活的G蛋白/PI-PLC/Ca通路会聚在一条不同的Wnt通路上，称为非典范的Wnt/Ca通路，它利用G蛋白和PI-PLC介导的钙释放来抑制典型的Wnt信号，导致神经脊的内源性细胞死亡。在这一竞争更新测试中，研究人员假设乙醇刺激的钙瞬变是凋亡的，因为它抑制了为神经峰提供营养支持的Wnt/S-连环蛋白信号。我们进一步认为，乙醇诱导的钙瞬变会聚并激活类似地抑制3-连环蛋白的非规范Wnt/Ca信号，从而导致内源性神经峰死亡。目的1检测乙醇诱导的钙瞬变是否抑制控制神经脊发育和存活的Wnt/(3-catenin)信号。我们将研究Wnt/p-catenin提供的营养支持的丧失是否导致它们的凋亡。目的2检测乙醇对Wnt/p-catenin的抑制作用是否由钙调蛋白依赖的激酶II(CaMKII)介导，CaMKII可将细胞内的瞬时钙离子转化为促细胞凋亡的信号。目的3检测乙醇诱导的神经脊细胞内钙瞬变是否由于汇聚并激活支配神经脊内源性细胞一致死亡的Wnt/Ca信号而破坏Wnt/p-catenin而导致细胞凋亡。这些研究是当前奖项的合乎逻辑的延伸。我们继续使用我们建立的鸡胚模型，该模型复制了包括人类在内的哺乳动物的酒精反应，具有描述良好的神经脊发育，现在可以使用功能增益或siRNA表达载体的电泳法进行遗传操作。WNT活性在脊椎动物中高度保守。它们是不同组织中细胞生长和分化的重要调节器，增加了WNTS代表胎儿和成人酒精作用的新靶点的可能性。