Scribble in hematopoietic stem cell activity

造血干细胞活性的涂鸦

• 批准号: 9122838
• 负责人: Mark Jordan Althoff
• 金额: $ 3.6万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9122838
• 关键词: Asses; Blood Cells; Bone Marrow; Cell Cycle; Cell Cycle Inhibition; Cell Cycle Progression; Cell Polarity; Cell Proliferation; Cell physiology; Cells; Chronic Disease; Complex; Confocal Microscopy; Cues; Cytoplasm; Data; Development; Disease; Euchromatin; Exhibits; Failure; Flow Cytometry; Genetic; Goals; Hematological Disease; Hematopoiesis; Hematopoietic; Hematopoietic System; Hematopoietic stem cells; Hereditary Disease; Image; Individual; Interferon Type I; Interferons; Intervention; Label; Larva; Leucine-Rich Repeat; Malignant Neoplasms; Measures; Mediating; Mesenchymal Stem Cells; Molecular; Molecular Target; Mus; Nuclear; Nuclear Translocation; Organ Size; Pathway interactions; Phosphorylation; Phosphotransferases; Population; Proteins; Regulation; Research Personnel; Resistance; Response Elements; Reverse Transcriptase Polymerase Chain Reaction; Role; STAT1 gene; STAT2 gene; Signal Pathway; Signal Transduction; Stem cell transplant; Stem cells; Stress; Structure; Testing; Therapeutic; Translating; Transplantation; Virus Diseases; Work; cancer genetics; cell behavior; cell type; chemotherapy; cytokine; cytopenia; exhaustion; hematopoietic stem cell fate; improved; in vivo; insight; leukemia; member; mutant; novel; progenitor; programs; public health relevance; reconstitution; response; self-renewal; transcriptome

 DESCRIPTION (provided by applicant): The potential of hematopoietic stem cells (HSC) to reconstitute the hematopoietic system has allowed for the development of transplantation approaches to treat cancer and hematologic diseases. Cell cycle status of HSC defines their ability to engraft in conditioned recipients and has been hypothesized as a mechanism for chemotherapy-resistant HSC-derived leukemias. HSC are highly quiescent cells with the ability to rapidly enter the cell cycle and differentiate through changes in their polarity and disposition of intracellular molecular fate determinants in response to microenvironment (ME) cues. In bone marrow (BM) hematopoiesis, interferons type I (IFN-I), a ME cytokine produced in response to viral infection, have been shown to be a crucial positive regulator to induce proliferation of otherwise quiescent hematopoietic stem cells (qHSC). Our preliminary data indicate that Scribble deficient HSC are insensitive to IFN-I and retain cellular quiescence in vivo. Our preliminary data also show that the Hippo effector Yap1, which also regulates stem cell proliferation in response to ME signals, is polarized and co-localizes in the cytoplasm with Scribble in wild type HSC. Deficiency of Scribble in HSC results in Yap1 translocation to nuclear euchromatin suggesting a novel Scribble-mediated mechanism used to protect qHSC from potential damage associated with cellular activation. Our data suggests that Scribble distinctly regulates HSC cell cycle progression in a context-dependent manner. We believe that ME IFN-I induced HSC proliferative signaling program depends on Scribble and that Scribble deficiency abrogates HSC polarization leading to reduced quiescence and subsequent HSC exhaustion through activation of downstream Hippo effectors. To gain insight into these ME dependent signaling pathways that control HSC activity, we plan to analyze both IFN-I response signaling pathways and Hippo signaling in Scribble proficient and deficient HSC. We will utilize flow cytometry and confocal microscopy to define a role for Scribble in mediating such signals. Functionally, we will test the reconstitution abilities of wild type and Scribble structure-functio mutants in Scribble deficient HSC through serial transplantations. Dissecting the microenvironment dependent Scribble-mediated molecular mechanisms that govern HSC quiescence will help refine the significance and therapeutic potential of naturally occurring IFN molecules and identify novel targets for intervention in HSC disease.

 描述（由申请人提供）：造血干细胞（HSC）重建造血系统的潜力已允许开发治疗癌症和血液疾病的移植方法。 HSC 的细胞周期状态决定了它们在条件接受者中的移植能力，并被假设为化疗耐药的 HSC 衍生性白血病的一种机制。 HSC 是高度静止的细胞，能够快速进入细胞周期并通过极性和性质的变化进行分化 细胞内分子命运决定因素响应微环境（ME）线索。在骨髓 (BM) 造血过程中，I 型干扰素 (IFN-I) 是一种响应病毒感染而产生的 ME 细胞因子，已被证明是诱导静止造血干细胞 (qHSC) 增殖的关键正调节因子。我们的初步数据表明，Scribble 缺陷型 HSC 对 IFN-I 不敏感，并在体内保持细胞静止状态。我们的初步数据还表明，Hippo 效应子 Yap1（也响应 ME 信号调节干细胞增殖）是极化的，并与野生型 HSC 中的 Scribble 共定位于细胞质中。 HSC 中 Scribble 的缺陷导致 Yap1 易位至核常染色质，这表明 Scribble 介导的新机制可用于保护 qHSC 免受与细胞激活相关的潜在损伤。我们的数据表明，Scribble 以上下文依赖性方式明显调节 HSC 细胞周期进程。我们认为 ME IFN-I 诱导的 HSC 增殖信号传导程序依赖于 Scribble，并且 Scribble 缺陷会消除 HSC 极化，从而减少静止状态，并通过激活下游 Hippo 效应器随后导致 HSC 耗竭。为了深入了解这些控制 HSC 活性的 ME 依赖性信号通路，我们计划分析 Scribble 熟练和缺陷的 HSC 中的 IFN-I 反应信号通路和 Hippo 信号通路。我们将利用流式细胞术和共聚焦显微镜来定义 Scribble 在介导此类信号中的作用。在功能上，我们将通过连续移植测试野生型和Scribble结构功能突变体在Scribble缺陷型HSC中的重建能力。剖析控制 HSC 静止的微环境依赖性 Scribble 介导的分子机制将有助于完善天然存在的 IFN 分子的意义和治疗潜力，并确定干预 HSC 疾病的新靶点。