Project 4: Epigenetic Mechanisms Modulating VWF

项目概要：项目4（ESI） 血管性血友病因子（VWF）是一种重要的止血蛋白， 出血和血栓形成VWF水平< 50 IU/dL代表出血的危险因素，而VWF水平< 30 IU/dL代表出血的危险因素。 IU/dL定义了维勒布兰德病（VWD），通常与VWF基因突变有关。 或者，高水平的VWF与血栓性疾病如心肌梗死和心肌梗死相关。 中风VWF水平在一般人群中的广泛分布表明存在多种因素 调节VWF水平。到目前为止，主要的修饰，如ABO血型和特定的基因变异， 参与VWF释放（STXBP 1，GNA 12）或清除（LRP 1，AVPR 2，ACE）仅占VWF释放（STXBP 1，GNA 12）或清除（LRP 1，AVPR 2，ACE）30-40% 已知的变化。该提案的目的是确定调节VWF的替代机制 程度.我们的中心假设是，内皮细胞的特定转录和表观遗传机制， 细胞是VWF水平的关键决定因素。该假设是基于最近的报告和我们的初步研究。 microRNAs水平（miRs），转录因子和表观遗传机制都可以改变VWF 程度.我们具有独特的优势，可以使用我们的主要患者源性血液生长来验证这一假设 内皮细胞（BOEC）准确复制疾病表型。我们将测试我们的假设通过 以下三个目标：（1）确定影响BOEC中VWF表达的转录机制， (2)VWF的甲基化和组蛋白乙酰化状态对VWF表达的贡献的确定 和（3）确定转录和表观遗传机制对VWF水平的作用， 衰老我们的初步数据和我们在BOEC模型方面的专业知识使我们能够很好地执行这些建议 研究目的。这些目标的成功完成将（1）证实VWF的新型转录调节因子在 低VWF BOEC，如miR-24和TCF 4，（2）证实了表观遗传修饰剂的调节作用，如 VWF启动子甲基化和组蛋白乙酰化，在决定VWF水平，和（3）证明新的 转录和表观遗传调控，可以解释衰老对VWF水平的影响。另外我们 无偏倚RNA测序、甲基化阵列和microRNA阵列也可以鉴定出其他靶点， VWF调节。在全球范围内，通过评估转录和表观遗传调节因子对VWF水平的作用， 预计我们将确定VWF表达和功能的新机制。这样的成果意义重大 因为它们有望促进对VWF编码区以外的修饰物如何 影响VWF水平，代表了VWF调节新途径， 考察

PROJECT SUMMARY: PROJECT 4 (ESI) Von Willebrand factor (VWF) is an essential hemostatic protein and alterations of VWF levels are associated with bleeding and thrombosis. VWF levels < 50 IU/dL represent a risk factor for bleeding while VWF levels < 30 IU/dL define Willebrand disease (VWD) and are often associated with mutations in the VWF gene. Alternatively, high levels of VWF are associated with thrombotic conditions such as myocardial infarction and stroke. The wide distribution of VWF levels in the general population indicates that there are multiple factors that regulate VWF levels. To date, major modifiers such as the ABO blood group and specific variants in genes implicated in VWF release (STXBP1, GNA12) or clearance (LRP1, AVPR2, ACE) account for only 30-40% of the known variation. The objective of this proposal is to identify alternative mechanisms that regulate VWF levels. Our central hypothesis is that specific transcriptional and epigenetic mechanisms in endothelial cells are critical determinants of VWF levels. The hypothesis is based on recent reports and our preliminary data that microRNAs levels (miRs), transcription factors, and epigenetic mechanisms can all modify VWF levels. We are uniquely positioned to test this hypothesis using our primary patient-derived blood outgrowth endothelial cells (BOECs) that replicate accurately the disease phenotype. We will test our hypothesis via the following three aims, (1) Determination of transcriptional mechanisms that affect VWF expression in BOECs, (2) Determination of the contribution of methylation and histone-acetylation status of VWF on VWF expression from BOECs and (3) Determination of the role of transcriptional and epigenetic mechanisms on VWF levels in aging. Our preliminary data and our expertise in BOEC models positions us well to carry out these proposed research aims. Successful completion of these aims will (1) confirm novel transcriptional regulators of VWF in low VWF BOECs, such as miR-24 and TCF4, (2) confirm the regulatory role of epigenetic modifiers, such as VWF promoter methylation and histone acetylation, in determining VWF levels, and (3) demonstrate novel transcriptional and epigenetic regulation that may explain the effects of aging on VWF levels. In addition, our un-biased RNA sequencing, methylation arrays, and microRNA arrays may also identify additional targets for VWF regulation. Globally, by evaluating the role of transcriptional and epigenetic regulators on VWF levels it is anticipated that we will identify novel mechanisms of VWF expression and function. Such results are significant as they are expected to advance the understanding of how modifiers outside of the VWF coding region can influence VWF levels and represent novel pathways of VWF regulation that have previously not been well examined.