Effects of PAHs on the Epigenome and Differentiation Capacity of Embryonic and Ne

描述（由申请人提供）：人胚胎干细胞（hESC）为研究细胞分化和人类发育提供了极好的模型系统。这些细胞可以产生来自所有三个胚层的细胞类型，具有用于细胞特异性群体的许多方案。然而，这一系统在确定环境影响方面，特别是在暴露于可能产生有害影响的有毒物质方面，没有得到充分利用。在这里，hESC将用于确定多环芳烃（PAH）如何改变hESC和ESC衍生的神经祖细胞（NPC）的表观基因组，以及这是否反过来影响它们的分化能力。作为原理证明，重点将放在广泛研究的7，8二羟基-9，10-环氧-7，8，9，10-四氢苯并[a]芘或BPDE上。已知BPDE形成可导致突变变化的DNA加合物，但其他证据表明，此类加合物通常靶向甲基化CpG。如前所述，通过对组蛋白修饰和DNA甲基化的全局作图和分析，hESC具有非常独特的表观基因组。确定胞嘧啶甲基化模式响应于不同浓度的BPDE而改变。因此，这里的目的是检查暴露是否对hESC和NPC分化的能力具有不利影响，关于谱系特化的时间或效率。此外，重要的是确定特定的基因组 BPDE-DNA加合物的位点。将利用ChIP-seq方面的专业知识，使用针对BPDE-DNA的抗体开发这些加合物的全球鉴定方法。

DESCRIPTION (provided by applicant): Human embryonic stem cells (hESCs) provide an excellent model system for studying cellular differentiation and human development. These cells can give rise to cell types from all three germ layers, with numerous protocols for cell-specific populations. However, this system has been under-utilized to determine the effects of the environment, specifically regarding exposure to toxic agents that can have a detrimental effect. Here hESCs will be used to determine how polycyclic aromatic hydrocarbons (PAHs) alter the epigenome of hESCs and ESC-derived neural progenitor cells (NPCs) and if this in turn affects their differentiation capacity. As proof of principle the focus will be on the widely studied 7,8 dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene or BPDE. BPDE is known to form DNA adducts that can lead to mutational changes, but additional evidence has shown that such adducts are often targeted to methylated CpGs. As has been previously demonstrated, hESCs have very unique epigenomes through the global mapping and analysis of histone modifications and DNA methylation. It was determined that cytosine methylation patterns change in response to different concentrations of BPDE. Therefore, the intent here is to examine if exposure has a detrimental effect on the ability of hESCs and NPCs to differentiate, with regards to timing or efficiency of lineage specification. In addition, it is important to determine the specific genomic sites of BPDE-DNA adducts. Expertise in ChIP-seq will be leveraged to develop a global identification method of these adducts using antibodies against BPDE-DNA.