The role of class IIa Hdac in regulating cell fate choice in early cortical development.

项目总结/摘要。项目2，D.达兰。 神经干细胞（NSC）和血管细胞之间的功能整合对于神经胶质细胞的形成至关重要 在皮质发育和神经胶质瘤进展过程中。血管细胞可作为表观遗传驱动因子诱导神经干细胞 特化和肿瘤转化。然而，这些表观遗传因素仍然定义不清。我们将确定 表观遗传机制调节神经干细胞的命运决定血管投资。我们有 建立了一个独特的神经干细胞-血管共培养系统，其中神经干细胞采取胶质细胞的命运，以响应血管 cues使用了转录组水平的无偏筛选方法，将IIa类Hdacs鉴定为 表观遗传驱动因素的潜在候选人在表达的组蛋白去乙酰化酶（Hdacs）中，只有类 IIa脑中表达的Hdacs（Hdacs 4、Hdacs 5、Hdacs 7）在血管共培养的NSC中上调， 提示它们在介导NSC向神经胶质细胞的转化中起作用。根据癌症的结果， 根据基因组图谱（TCGA），IIa类Hdacs水平升高也与人类神经胶质瘤肿瘤分级相关， 特别是HSP 4和HSP 5。IIa类Hdacs具有从细胞质移动到细胞质的独特能力。 细胞核，募集蛋白质伴侣，如Hdac 3和Mecp 2，以促进脱乙酰化反应。此属性 使它们成为研究微环境线索的有吸引力的候选者。我们发展了一种共文化 一个模拟NSC与血管细胞（内皮细胞和周细胞）相互作用的系统，并将使用它来 在早期皮质神经干细胞对血管环境信号的反应中， 发展和神经胶质瘤血管模型。在这里，我们测试的假设，在IIa类Hdacs的变化是 对血管细胞发育线索的胶质细胞生成和癌症期间的胶质母细胞瘤至关重要 进展在目标1中，我们将测试在神经-血管共培养物中，IIa类Hdacs是否是神经胶质细胞生成所必需的 模型工作假设是IIa类Hdacs表达的增加先于细胞凋亡。 在血管细胞衍生的Lif衍生的影响下从NSC向神经胶质细胞的命运转变。在目标2中，我们将测试 IIa类Hdacs是血管共培养模型中胶质瘤进展所必需的。由于IIa类障碍物 在人胶质母细胞瘤中上调，工作假设是IIa类Hdacs是胶质母细胞瘤所需的。 胶质母细胞瘤阶段转变发生在高度血管化的微环境中。我们预测IIa类 Hdacs通过减少增殖和干细胞特异性的转录来调节染色质结构的变化 基因和在发展过程中诱导胶质细胞生成或促进胶质瘤进展， 投资拟议的研究解决了一个关键的需要，了解如何微环境诱导， 基于乙酰化的染色质修饰影响发育过程中和胶质瘤中的皮质胶质细胞生成 肿瘤进展。建立的模型系统也将为测试潜在的 在胶质母细胞瘤-血管细胞培养模型中用于预防肿瘤转化的基于IIa类Hdac的靶标。

PROJECT SUMMARY/ABSTRACT. PROJECT 2, D. DARLAND. Functional integration between neural stem cells (NSC) and vascular cells is critical for neural-glia formation during cortical development and glioma progression. Vascular cells can act as epigenetic drivers to induce NSC specification and tumor transformation. However, these epigenetic factors remain poorly defined. We will identify epigenetic mechanisms that regulate NSC fate decisions in response to vascular investment. We have established a unique NSC-vascular coculture system in which NSC adopt a glial fate in response to vascular cues have used a transcriptome-level, unbiased screening approach that has identified Class IIa Hdacs as potential candidates for the epigenetic drivers. Of the histone deacetylases (Hdacs) expressed, only the Class IIa Hdacs expressed in the brain (Hdac 4, Hdac 5, Hdac 7) were upregulated in NSC in vascular coculture, suggesting that they play a role in mediating NSC transition to glial cells. Based on results from the Cancer Genome Atlas (TCGA), elevated levels of Class IIa Hdacs are also associated with human glioma tumor grades, particularly Hdac 4 and Hdac 5. The Class IIa Hdacs have the unique ability to move from the cytoplasm to the nucleus, recruiting protein partners such as Hdac3 and Mecp2 to facilitate deacetylation reactions. This property makes them attractive candidates to transduce microenvironmental cues. We have developed a coculture system that models NSC interactions with vascular cells (endothelial cells and pericytes) and will use this to address the question of NSC fate decisions in response to vascular environmental cues in early cortical development and in a glioma-vascular model. Here we test the hypothesis that changes in Class IIa Hdacs are critical for gliogenesis in response to vascular cell developmental cues and in glioblastoma during cancer progression. In Aim 1 we will test if Class IIa Hdacs are required for gliogenesis in a neural-vascular coculture model. The working hypothesis is that increasing expression of Class IIa Hdacs expression precedes the cell fate transition from NSC to glia under the influence of vascular cell-derived Lif derived. In Aim 2 we will test if Class IIa Hdacs are required for glioma progression in a vascular coculture model. Since Class IIa Hdac are upregulated in human glioblastoma, the working hypothesis is that Class IIa Hdacs are required for the glioblastoma stage transition that occurs in a highly vascular microenvironment. We predict that the Class IIa Hdacs regulate changes in chromatin structure by decreasing transcription of proliferation and stem-specific genes and inducing gliogenesis during development or promoting glioma progression in response to vascular investment. The proposed studies address a critical need to understand how microenvironment-induced, acetylation-based modifications to chromatin influence cortical gliogenesis during development and in glioma tumor progression. The model systems established will also provide a valuable resource for testing potential Class IIa Hdac-based targets for preventing tumor transition in a glioblastoma-vascular cell culture model.