Epigenetic changes and disturbed neural development in a human embryonic stem cell-based model relating to the fetal valproate syndrome
Epigenetic changes and disturbed neural development in a human embryonic stem cell-based model relating to the fetal valproate syndrome
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DOI：
10.1093/hmg/dds239
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发表时间：
2012-09-15
影响因子：
3.5
通讯作者：
Leist, Marcel
中科院分区：
文献类型：
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作者：
Balmer, Nina V.;Weng, Matthias K.;Leist, Marcel
妊娠期暴露于抗癫痫药物丙戊酸（VPA）会导致日后的神经功能和解剖缺陷。目前，关于化学物质如何影响早期神经发育的人类数据很少。我们使用分化为神经外胚层前体的人胚胎干细胞作为模型来研究VPA的作用模式。使用微阵列表达谱分析、特异性标记基因的qPCR、免疫染色和在典型神经前体细胞标记物HES 5的启动子控制下的绿色荧光蛋白的表达作为读数。暴露于VPA导致标记基因表达扭曲，其特征为NANOG和OCT 4相对增加，PAX 6减少。类似的反应模式，观察到与阿伐他汀A，一种有效的和特定的组蛋白去乙酰化酶抑制剂（HDACi），但没有与其他几种毒物。分化标志物被长期干扰，但不是由急性治疗HDACi，和最强的分化干扰观察到毒物暴露在早期神经命运的决定。在HDACi存在下观察到的组蛋白乙酰化增加可以解释一些基因的上调。然而，为了了解PAX6的下调和整体复杂的转录变化，我们进一步检查了表观遗传标记。在PAX6和OCT 4的启动子区域检测到组蛋白H3的赖氨酸4和27的甲基化的改变。这些激活和沉默组蛋白标记的变化为在非细胞毒性药物浓度下调节发育重要基因提供了更普遍的机制理性。
Exposure to the antiepileptic drug valproic acid (VPA) during gestation causes neurofunctional and anatomic deficits in later life. At present, there are little human data on how early neural development is affected by chemicals. We used human embryonic stem cells, differentiating to neuroectodermal precursors, as a model to investigate the modes of action of VPA. Microarray expression profiling, qPCR of specific marker genes, immunostaining and the expression of green fluorescent protein under the control of the promoter of the canonical neural precursor cell marker HES5 were used as readouts. Exposure to VPA resulted in distorted marker gene expression, characterized by a relative increase in NANOG and OCT4 and a reduction in PAX6. A similar response pattern was observed with trichostatin A, a potent and specific histone deacetylase inhibitor (HDACi), but not with several other toxicants. Differentiation markers were disturbed by prolonged, but not by acute treatment with HDACi, and the strongest disturbance of differentiation was observed by toxicant exposure during early neural fate decision. The increased acetylation of histones observed in the presence of HDACi may explain the up-regulation of some genes. However, to understand the down-regulation of PAX6 and the overall complex transcript changes, we examined further epigenetic markers. Alterations in the methylation of lysines 4 and 27 of histone H3 were detected in the promoter region of PAX6 and OCT4. The changes in these activating and silencing histone marks provide a more general mechanistic rational for the regulation of developmentally important genes at non-cytotoxic drug concentrations.