TOBACCO EXPOSURE BIOMARKERS AND MUTATIONS OF MSX1 AND IRF6 GENES IN PREGNANCY

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。怀孕期间接触烟草烟雾会使发育中的胎儿面临与吸烟有关的严重后果的风险增加。最值得注意的是，宫内发育迟缓和出生体重下降被认为是宫内接触烟草的直接后果。然而，怀孕期间吸烟的其他有害影响也已被确定，包括增加出生缺陷的风险。在烟草中发现的数千种化合物中，对这些变化进行了详细研究的只有少数几种。最值得注意的是烟草特有的亚硝胺，这显然与动物模型中的实验性口腔面部缺陷有关。流行病学研究已经证实，母亲吸烟与人类患唇腭裂风险增加之间存在显著的正相关关系。分析烟草成分对小鼠颅面发育影响的研究提供了明确的证据，表明暴露于烟草烟雾会破坏形态学事件。与出生缺陷，特别是口面部缺陷相关的特定基因已被广泛研究，但这些基因与烟草中可能改变这些基因表达的特定化合物以及特定烟草致癌物质的代谢和解毒之间的联系尚未开展。在拟议的研究中，我们将招募在怀孕期间吸烟的母亲，调查怀孕期间吸烟与子宫内接触烟草对与出生缺陷相关的特定基因的影响之间的关系。我们将通过评估分娩时获得的母体和胎儿血液样本中化合物的蛋白质加合物，定性和定量地评估烟草暴露情况，特别是烟草特异性亚硝胺NNN （N'-亚硝基尼古丁）和NNK（4-（甲基亚硝胺）-1-（3-吡啶基）-1-丁酮）以及苯并(a)芘。我们将对与烟草致癌物代谢激活和失活相关的特定酶CYP1A1和微粒体环氧化物水解酶（MeH）进行基因分型。我们将分离母体和胎儿的DNA，并鉴定可能与烟草烟雾引起的出生缺陷有关的基因。为了将烟草暴露与与出生缺陷相关的特定基因联系起来，我们将检查和测序已知在口腔面部缺陷病因学中起作用的两个基因，MSX1和IRF6基因。我们将把各种基因的突变与吸烟状况以及检测到的烟草特定化合物的生物标志物联系起来。这种联系将有助于确定吸烟，特别是在怀孕期间吸烟，烟草中特定的已知致畸物，以及已知与出生缺陷有关的特定基因突变之间的关系。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Exposure to tobacco smoke during pregnancy places the developing fetus at an elevated risk of severe outcomes related to smoke exposure. Most notably, intrauterine growth retardation as well as decrease in birth weight have been measured as direct consequence of tobacco exposure in utero. However, other harmful effects of tobacco smoking during pregnancy have also been identified, including an elevated risk of birth defects. Of the thousands of compounds found in tobacco, only a few have been studied in detail with respect to these changes. Most notably are the tobacco specific nitrosamines, which have clearly been linked to experimental orofacial defects in animal models. Epidemiological studies have established a significant positive correlation between maternal smoking and an increased risk for orofacial clefts in humans. Studies analyzing the effect of tobacco constituents on mouse craniofacial development have provided clear evidence that the morphologic events can be disrupted by exposure to tobacco smoke. Specific genes related to the development of birth defects, especially orofacial defects have been widely studied, but the link between these genes and specific compounds in tobacco that may alter these genes expression and the metabolism and detoxification of specific tobacco carcinogens has not been carried out. In the proposed study we will recruit mothers that have smoked during pregnancy and investigate the relationship between smoking during pregnancy and the effects that tobacco exposure has in utero on specific genes related to birth defects. We will qualitatively and quantitatively assess exposure to tobacco and specifically to the tobacco specific nitrosamines NNN (N'-nitrosonornicotine) and NNK (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone) as well as benzo(a)pyrene by assessment of protein adducts to the compounds in maternal and fetal blood samples obtained at delivery. We will carry out genotyping to specific enzymes related to metabolic activation and deactivation of tobacco carcinogens, CYP1A1 and microsomal epoxide hydrolase (MeH). We will isolate maternal and fetal DNA and characterize genes that are potentially related to the birth defects caused by tobacco smoke. In order to link tobacco exposure with specific genes related to birth defects, we will examine and sequence two genes that are known to play a role in the etiology of orofacial defects, the MSX1 and IRF6 genes. We will correlate mutations in the various genes with smoking status as well as biomarkers detected for the tobacco specific compounds. This link will assist in determining the relationships between smoking, especially during pregnancy, specific known teratogens in tobacco, and mutations in specific genes that are known to be related to birth defects.