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。这些细胞可以产生来自所有三个生殖层的细胞类型，并有许多针对特定细胞群体的方案。然而，这一系统在确定环境影响方面一直未得到充分利用，特别是在暴露于可能产生有害影响的有毒物质方面。在这里，我们将利用hESCs来确定多环芳烃(PAHs)如何改变hESCs和ESC来源的神经前体细胞(NPC)的表观基因组，以及这是否反过来影响它们的分化能力。作为原则证明，重点将放在被广泛研究的7，8 dihydroxy-9，10-epoxy-7，8，9，10-tetrahydrobenzo[a]pyrene或BPDE上。众所周知，BPDE可以形成DNA加合物，导致突变，但更多的证据表明，这种加合物通常针对甲基化的CPGS。正如先前所证明的，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。已确定胞嘧啶甲基化模式随着不同浓度的BPDE的反应而改变。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，涉及谱系指定的时间或效率。此外，确定特定的基因组也很重要 BPDE-DNA加合物的位置。将利用CHIP-SEQ方面的专业知识，开发一种使用BPDE-DNA抗体对这些加合物进行全球鉴定的方法。

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.