Interactions between Shh pathway regulators and fetal alcohol exposure in mice

Shh 通路调节因子与小鼠胎儿酒精暴露之间的相互作用

基本信息

批准号：
8516408
负责人：
Robert S. Krauss
金额：
$ 35.3万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-30 至 2014-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8516408
关键词：
129/Sv Mouse Alcohol consumption Alobar Holoprosencephaly Animal Model Anterior nares Apoptosis Binding C57BL/6 Mouse Cell Surface Proteins Clinical Complex Congenital Abnormality Counseling Defect Development Digit structure Down-Regulation Ectoderm Embryo Employee Strikes Environmental Exposure Environmental Risk Factor Erinaceidae Ethanol Etiology Face Failure Fetal Alcohol Exposure Fetal Development Frequencies Genes Genetic Genetic Predisposition to Disease Genetic Variation Goals Holoprosencephaly Human Impairment Light Limb Bud Limb structure Microforms Modeling Mus Mutant Strains Mice Mutation Outcome Pattern Penetrance Phenotype Population Pregnancy Process Prosencephalon Protein Binding Public Health Reporting Resistance Role Severities Signal Pathway Signal Transduction Sonic Hedgehog Pathway Staging Structure Teratogens Time Ursidae Family Zebrafish alcohol exposure craniofacial developmental genetics gene environment interaction genetic analysis genetic pedigree in utero insight malformation mouse model mutant mutation carrier palatogenesis receptor smoothened signaling pathway

项目摘要

Holoprosencephaly (HPE) is a common birth defect of the forebrain and midface with both environmental and genetic causes. Among the environmental factors is maternal alcohol consumption during early pregnancy. In addition, mutations in the Sonic hedgehog (Shh) signaling pathway have been identified in human HPE. The HPE phenotype of mutation carriers is highly variable, with the spectrum of effects ranging in a continuum from severe defects in the forebrain and midface to no clinical manifestation. The reason for this variability is un- known, but factors that may also be required include additional genetic influences or environmental exposures during fetal development. Gene-environment interactions are likely to be involved in a complex malady like HPE; however, there are few models for this. Cdo and Boc are cell surface proteins that bind Shh and regulate pathway signaling strength in specific regions of the developing embryo. Cdo mutant mice display HPE with strain-specific severity: mutants on the 129/Sv background show very mild HPE with low frequency, while mutants on the C57BL/6 background show more severe forms at high frequency. Boc mutant mice are without overt effect, but 129/Sv Cdo;Boc double-mutants display severe craniofacial HPE features. We report that 129/Sv mice are resistant to ethanol-induced HPE; however, 80% of 129/Sv Cdo mutant embryos exposed in utero to ethanol display strong craniofacial HPE and bear a striking resemblance to Cdo;Boc double mutants. Furthermore, there is a strong reduction of Shh expression in the forebrain of ethanol-treated Cdo mutant embryos. Loss of Cdo and fetal ethanol exposure therefore synergize to produce HPE; this fact, plus that ethanol-treated Cdo mutant embryos are so similar to Cdo;Boc double-mutants, argues that loss of Cdo and ethanol exposure have a synergistic effect on Shh signaling. Limb and digit defects are also associated with human fetal alcohol exposure, and in utero ethanol exposure of C57BL/6 embryos results in malformations of the posterior aspects of limbs and digits. Shh is required for all posterior patterning of limbs and digits. Loss of Boc, but not Cdo, results in severe digit defects on a genetically-sensitized background. It is hypothesized that, similar to 129/Sv Cdo mutant mice and HPE, 129/Sv Boc mutant mice will be sensitized to ethanol-induced limb/digit anomalies. There is relatively little information available on how ethanol disrupts the known regulators of limb/digit patterning, and developmental genetic analyses of ethanol-treated C57BL/6 and 129/Sv mice will shed light on this process. The aims of this proposal are: 1) to analyze ethanol-induced HPE in 129/Sv Cdo mutant mice; 2) to identify mechanisms of ethanol-induced down-regulation of Shh expression in the forebrains of 129/Sv Cdo mutant mice; and 3) to analyze the role of the Shh pathway in ethanol-induced defects in limb/digit patterning. These studies involve analysis of a newly developed model of gene-environment interaction between a defined developmental mutation and ethanol in a common birth defect. Such information may have important public health impact and could ultimately aid in the counseling of mutation carriers.

前脑无裂畸形 (HPE) 是一种常见的前脑和中面部出生缺陷，与环境和遗传原因。环境因素之一是孕早期母亲饮酒。在此外，在人类 HPE 中还发现了 Sonic Hedgehog (Shh) 信号通路的突变。这突变携带者的 HPE 表型变化很大，其影响范围在连续范围内前脑和中面部严重缺陷，无临床表现。造成这种变化的原因是已知，但可能还需要因素包括额外的遗传影响或环境暴露在胎儿发育期间。基因与环境的相互作用可能与复杂的疾病有关，例如慧与；然而，这方面的模型很少。 Cdo 和 Boc 是结合 Shh 并调节的细胞表面蛋白发育胚胎特定区域的通路信号强度。 Cdo突变小鼠表现出HPE 菌株特异性严重程度：129/Sv 背景上的突变体表现出非常轻微的 HPE，频率较低，而 C57BL/6 背景上的突变体在高频下表现出更严重的形式。 Boc突变小鼠没有效果明显，但 129/Sv Cdo;Boc 双突变体表现出严重的颅面 HPE 特征。我们报告说 129/Sv小鼠对乙醇诱导的HPE有抵抗力；然而，80%的129/Sv Cdo突变胚胎暴露于子宫内乙醇显示出强烈的颅面 HPE，并且与 Cdo;Boc 双突变体具有惊人的相似性。此外，乙醇处理的 Cdo 突变体的前脑中 Shh 表达显着降低胚胎。因此，Cdo 的损失和胎儿乙醇暴露会协同产生 HPE；这个事实，加上那个乙醇处理的 Cdo 突变体胚胎与 Cdo;Boc 双突变体非常相似，认为 Cdo 和 Boc 的损失乙醇暴露对 Shh 信号传导有协同作用。肢体和手指缺陷也与人类胎儿酒精暴露以及 C57BL/6 胚胎的子宫内乙醇暴露会导致畸形四肢和手指的后部。四肢和手指的所有后部模式都需要“嘘”。损失 Boc（而非 Cdo）会在遗传敏感的背景下导致严重的手指缺陷。据推测，与129/Sv Cdo突变小鼠和HPE类似，129/Sv Boc突变小鼠会对乙醇诱导过敏肢体/手指异常。关于乙醇如何破坏已知监管机构的信息相对较少乙醇处理的 C57BL/6 和 129/Sv 小鼠的肢体/手指模式和发育遗传分析将阐明了这一过程。该提案的目的是：1）分析 129/Sv Cdo 中乙醇诱导的 HPE 突变小鼠； 2）确定乙醇诱导前脑Shh表达下调的机制 129/Sv Cdo 突变小鼠； 3）分析Shh通路在乙醇诱导的缺陷中的作用肢体/数字模式。这些研究涉及对新开发的基因环境模型的分析在常见的出生缺陷中，确定的发育突变与乙醇之间的相互作用。此类信息可能对公共卫生产生重要影响，并最终有助于突变携带者的咨询。