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

描述（申请人提供）：人类胚胎干细胞（hESCs）为研究细胞分化和人类发育提供了一个极好的模型系统。这些细胞可以从所有三个胚层中产生细胞类型，具有许多细胞特异性群体的方案。然而，这一系统在确定环境的影响方面，特别是在接触可能产生有害影响的有毒物质方面，尚未得到充分利用。在这里，hESCs将用于确定多环芳烃（PAHs）如何改变hESCs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。众所周知，BPDE会形成可导致突变变化的DNA加合物，但额外的证据表明，这种加合物通常是甲基化CpGs的目标。如前所述，通过组蛋白修饰和DNA甲基化的全球定位和分析，hESCs具有非常独特的表观基因组。结果表明，胞嘧啶甲基化模式随着BPDE浓度的不同而改变。因此，这里的目的是检查暴露是否对hESCs和npc的分化能力有不利影响，涉及谱系规范的时间或效率。此外，确定特定的基因组也很重要

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. PUBLIC HEALTH RELEVANCE: The investigators will establish human embryonic stem cells and neural progenitor cells as a system for determining the environmental epigenomic effects on these progenitor populations by exposure to the polycyclic aromatic hydrocarbon BPDE. They will determine if this affects the differentiation capacity and results in changes to global DNA methylation. The investigators will also develop a method to determine the genome-wide location of DNA adducts caused by BPDE, called BPDE-DNA-seq.