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

项目摘要/摘要。项目2，D.达兰德。 神经干细胞和血管细胞之间的功能整合对神经胶质细胞的形成至关重要 在皮质发育和胶质瘤进展过程中。血管细胞可作为表观遗传驱动因素诱导神经干细胞 规范与肿瘤转化。然而，这些表观遗传因素仍然没有得到明确的定义。我们将确定 调控神经干细胞命运决定的表观遗传机制，以响应血管投资。我们有 建立了一种独特的神经干细胞-血管共培养体系，在该体系中，神经干细胞对血管采取了神经胶质细胞的命运 CUES使用了转录组水平的、无偏见的筛选方法，将IIa类HDAC鉴定为 表观遗传驱动因素的潜在候选者。在表达的组蛋白脱乙酰基酶中，只有类 在血管共培养中，脑内表达的IIa HDAC(HDAC 4、HDAC 5、HDAC 7)在NSC中上调。 提示它们在神经干细胞向神经胶质细胞的转化过程中起重要作用。基于癌症的研究结果 基因组图谱(TCGA)，IIa类HDAC水平升高也与人脑胶质瘤肿瘤分级有关， 尤其是HDAC 4和HDAC 5。IIa类HDAC具有独特的能力，可以从细胞质移动到 核，招募蛋白质伙伴，如HDAC3和MeCP2，以促进脱乙酰基反应。此属性 使它们成为传递微环境线索的有吸引力的候选者。我们发展了一种共同的文化 模拟神经干细胞与血管细胞(内皮细胞和周细胞)相互作用的系统，并将使用该系统 解决神经干细胞在皮质早期对血管环境线索做出命运决定的问题 在一个神经胶质瘤血管模型中。在这里，我们测试这样一个假设，即IIa类HDAC中的更改 肿瘤期间血管细胞发育信号对胶质形成和胶质母细胞瘤的关键作用 进步。在目标1中，我们将测试在神经-血管共培养中是否需要IIa类HDAC来促进神经胶质的发生 模特。工作假设是IIa类HDACs表达的增加先于细胞 在血管细胞来源的LIF来源的影响下，NSC向神经胶质细胞的命运转变。在目标2中，我们将测试 在血管共培养模型中，IIa类HDAC对于胶质瘤的进展是必需的。由于IIa类HDAC是 在人脑胶质母细胞瘤中上调，工作假说是IIa类HDAC是 在高度血管的微环境中发生的胶质母细胞瘤的分期转变。我们预测IIa级 HDAC通过减少增殖和干细胞特异性转录来调节染色质结构的变化 基因和在发育过程中诱导胶质形成或促进胶质瘤进展对血管的反应 投资。拟议的研究解决了理解微环境如何诱导、 染色质乙酰化修饰对发育期间和胶质瘤皮质胶质形成的影响 肿瘤进展。所建立的模型系统也将为测试潜力提供宝贵的资源 在胶质母细胞瘤-血管细胞培养模型中，基于IIa类HDAC的靶点用于预防肿瘤转移。

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.