Environmental influences of Ah receptor ligands on gene expression

超级基金场地化学品，如多环芳烃（PAH）、卤代芳烃（HAH）和多氯联苯（PCB）是已知的人类健康毒物。它们的毒性与基因表达的改变有关。这些试剂激活基因的分子机制与二恶英或芳烃（Ah）受体（AhR）的激活有关。我们的实验室和其他实验室已经证明，AhR配体通过修饰其他信号转导途径（如蛋白激酶C调控下的信号转导途径）来传递基因激活信号。有证据表明，氧化应激诱导的途径，如蛋白激酶C。有证据表明，氧化应激诱导的途径，如JNK和NF-κ B也可能参与AhR配体介导的基因表达。根据SBRP的主题，我们将研究AhR配体对基因表达的作用。我们正在开发一种灵敏的AhR配体报告基因系统，该系统利用β-内酰胺酶基因作为报告系统。该AhR-报告基因系统将可用作监测混合物中AhR配体存在的模型。为了进一步了解与AhR配体毒性相关的潜在机制，概述了实验以表征由AhR依赖性机制靶向的基因和由PKC和AP-1协同调节的基因。其他途径连接AhR配体诱导的基因表达的氧化应激介导的机制也将进行检查。我们将利用微阵列技术核心中提供的专业知识，筛选微阵列芯片上的小鼠EST，以识别被这些毒物修饰的基因。随着新基因和cDNA的发现，它们将在组织培养细胞中表达后进行表征，我们将利用大分子表征核心来帮助这些研究。最后，为了研究一些改变的基因及其功能作用，我们将在小鼠遗传学核心的帮助下敲除小鼠中的选定基因。SBRP的广泛范围和研究超级基金毒物对基因表达的作用的集中目标将使我们能够与Karin博士（项目1），Tsien博士（项目3），Kelner博士（项目5）和Glass博士（项目6）密切合作，以更好地了解这些药物毒性作用中涉及的信号转导途径。

Superfund site chemicals such as polycyclic aromatic hydrocarbons (PAHs), halogenated aromatic hydrocarbons (HAHs) and polychlorinated biphenyls (PCBs) are known human health toxicants. Their toxicity is associated with altered gene expression. The molecular mechanisms that underlie gene activation by these agents are linked to activation of the dioxin or aryl hydrocarbon (Ah) receptor (AhR). Our laboratory and others have demonstrated that AhR ligands signal gene activation by modifying other signal transduction pathways such as those under the regulation of protein kinase C. Evidence is presented that oxidative-stress induced pathways such as those under the protein kinase C. Evidence is presented that oxidative-stress induced pathways, such as JNK and NF- kappaB may also participate in AhR ligand mediated gene expression. In line with the theme of the SBRP, we will be examining the actions of AhR ligands on gene expression. We are developing a sensitive AhR ligand reporter gene system that takes advantage of the beta-lactamase gene as the reporter system. This AhR-reporter gene system will be useful as a model for monitoring the presence of AhR ligands in mixtures. To further understand the underlying mechanisms associated with AhR ligand toxicity, experiments are outlined to characterize genes that are targeted by AhR dependent mechanisms and those that are coordinately regulated by PKC and AP-1. Other pathways that link AhR Ligand induced gene expression by oxidative-stress mediated mechanisms will also be examined. We will take advantage of the expertise offered in the Microarray Technology Core to screen mouse ESTs spotted on microarray chips to identify those genes modified by these toxicants. As new genes and cDNAs are discovered, they will be characterized following expression in tissue culture cells, and we will utilize the Macromolecular Characterization Core for help with these studies. Finally, to the study and functional role of some of the altered genes, we will knock-out selected genes in mice with help from the Mouse Genetics Core. The broad scope of the SBRP and the centralized goals to study the actions of Superfund toxicants on gene expression will allow us to work closely with Drs. Karin (Project 1), Tsien (Project 3), Kelner (Project 5) and Glass (Project 6) to better understand the signal transduction pathways involved in the toxic actions of these agents.