Defining the Role of Alternative Polyadenylation in Macrophage Differentiation and Function

项目摘要： 巨噬细胞是免疫系统的关键效应细胞，具有杀死微生物的关键功能， 产生炎症调节剂和组织修复。然而，过度的巨噬细胞反应 导致癌症以及炎性和变性疾病的病理学。此外，本发明还提供了一种方法， 巨噬细胞前体的不受抑制的增殖代替分化导致急性髓性白血病。到 更好地解决如何调节巨噬细胞功能，以帮助减轻疾病，涉及的变化， 巨噬细胞生物学，我们必须了解控制巨噬细胞的关键分子途径 分化并调节其活性。 我们认为，这些途径之一将涉及mRNA聚腺苷酸化，一个重要的成熟步骤， 所述mRNA前体在其3'末端被修剪并添加聚（A）尾（pA）。改变PA的位置 一个位点通过一个称为交替多聚腺苷酸化（阿帕）的过程起着重要的作用， 在基因表达调控中的作用。3'非翻译区的缩短可以去除调节性的蛋白质。 控制RNA稳定性、翻译和亚细胞定位的序列，而编码区 缩短可以显著改变蛋白质功能。虽然阿帕在肿瘤中的变化是全局性的， 进展和其他类型的细胞分化，阿帕对巨噬细胞分化的贡献 尚未被研究。 我们假设阿帕的整体变化是巨噬细胞分化所必需的，并且这种变化是 由阿帕监管机构不断变化的水平驱动。我们的目标是确定阿帕如何有助于 巨噬细胞分化，长期目标是定义如何在治疗中操纵这一点。 以促进分化和调节巨噬细胞功能。我们的具体目标将1）决定 巨噬细胞分化过程中阿帕的整体模式，受阿帕影响的基因的功能类别， 和可能表征这些位点的序列特征，2）定义巨噬细胞阿帕的驱动因子， 改变它们的表达对分化以及充分表征的巨噬细胞 功能，如细胞因子的产生，迁移和吞噬作用，和3）确定的分子 改变调节阿帕蛋白水平的机制。因为巨噬细胞是 许多疾病的防御和它们分化的失调导致白血病，我们提出的研究 应该最终通知新的治疗工具，以调节巨噬细胞的生产。他们还将广泛 推进我们对一般和组织特异性阿帕范例的理解。S

Project Summary: Macrophages are key effector cells of the immune system, with critical functions in killing of microbes, production of inflammatory regulators, and tissue repair. However, an excessive macrophage response contributes to the pathology of cancer as well as inflammatory and degenerative diseases. In addition, unchecked proliferation of macrophage precursors in lieu of differentiation leads to acute myeloid leukemia. To better address how to modulate macrophage function to help abate diseases that involve changes in macrophage biology, we must understand the critical molecular pathways that govern macrophage differentiation and regulate their activity. We propose that one of these pathways will involve mRNA polyadenylation, an essential maturation step in which mRNA precursor is trimmed at its 3' end and a poly(A) tail (pA) added. Changing the position of the pA site through a process called alternative polyadenylation (APA) plays an important, increasingly appreciated role in regulation of gene expression. Shortening of the 3' untranslated region can remove regulatory sequences that control RNA stability, translation, and subcellular localization, whereas coding region shortening can dramatically alter protein function. While global changes in APA have been observed in tumor progression and other types of cellular differentiation, the contribution of APA to macrophage differentiation has not been studied. We hypothesize that a global shift in APA is required for macrophage differentiation and that this shift is driven by changing levels of APA regulators. Our objective is to determine how APA contributes to macrophage differentiation, with the long-range goal of defining how this might be manipulated in therapeutic settings to promote differentiation and modulate macrophage function. Our specific aims will 1) determine the global pattern of APA during macrophage differentiation, the functional classes of genes impacted by APA, and sequence features that might characterize these sites, 2) define drivers of macrophage APA and the consequence that altering their expression has on differentiation as well as well-characterized macrophage functions such as cytokine production, migration, and phagocytosis, and 3) determine the molecular mechanisms that alter the levels of the proteins that regulate APA. Because macrophage are a first line of defense for many diseases and dysregulation of their differentiation leads to leukemias, our proposed studies should ultimately inform new therapeutic tools to modulate macrophage production. They will also broadly advance our understanding of general and tissue-specific APA paradigms. s