Defining the Role of Alternative Polyadenylation in Macrophage Differentiation and Function

项目总结： 巨噬细胞是免疫系统的关键效应细胞，在杀死微生物方面具有关键作用， 产生炎症调节剂，以及组织修复。然而，过度的巨噬细胞反应 对癌症以及炎症性和退行性疾病的病理有贡献。此外, 巨噬细胞前体无节制地增殖而不是分化导致急性髓系白血病。至 更好地解决如何调节巨噬细胞功能，以帮助减轻涉及变化的疾病 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 分化和调节它们的活动。 我们认为，其中一个途径将涉及mR NA的多腺苷基化，这是一个重要的成熟步骤。 该信使核糖核酸前体在其3‘端被修剪，并添加聚(A)尾巴(PA)。更改页面的位置 通过一种称为替代聚腺苷酸化(APA)的过程，位点发挥着重要的作用，越来越受到人们的重视 在基因表达调控中的作用。缩短3‘非翻译区可以去除调控 控制RNA稳定性、翻译和亚细胞定位的序列，而编码区 缩短时间可以显著改变蛋白质的功能。虽然APA在肿瘤中的整体变化已被观察到 进展和其他类型的细胞分化，APA对巨噬细胞分化的贡献 还没有被研究过。 我们假设APA的全球转变是巨噬细胞分化所必需的，而且这种转变是 由不断变化的APA监管机构级别推动。我们的目标是确定APA如何有助于 巨噬细胞分化，长期目标是确定这可能是如何在治疗中操纵的 促进分化和调节巨噬细胞功能的设置。我们的具体目标将决定 巨噬细胞分化过程中APA的整体模式，受APA影响的基因的功能类别， 和序列特征，2)定义巨噬细胞APA的驱动因素和 改变它们的表达对分化和特征良好的巨噬细胞的影响 细胞因子的产生、迁移和吞噬等功能，以及3)决定分子 改变调节APA的蛋白质水平的机制。因为巨噬细胞是 对许多疾病的防御和它们的分化失调导致白血病，我们建议的研究 最终应该会提供新的治疗工具来调节巨噬细胞的产生。他们还将广泛地 促进我们对一般和组织特异性APA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