Wnt signaling and hematopoietic stem cells

Wnt信号传导与造血干细胞

• 批准号: 7875243
• 负责人: ROBERT O'Mara RYAN
• 金额: $ 18.71万
• 依托单位: CHILDREN'S HOSPITAL & RES CTR AT OAKLAND
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7875243
• 关键词: Affect; Apolipoprotein A-I; Apolipoprotein E; Apolipoproteins; Binding; Biological; Biological Assay; Cell Nucleus; Cell Surface Receptors; Cells; Cholates; Complex; Dialysis procedure; Disease; Gel Chromatography; Gene Targeting; Genetic Transcription; Goals; Hematopoietic stem cells; Hydrophobicity; Immunoprecipitation; LDL-Receptor Related Protein 1; Lipid Binding; Lipids; Lipoproteins; Liposomes; Mediating; Methods; Molecular Conformation; Nature; Outcome; Protein Family; Public Health; Recombinants; Regulation; Reporter; Research; Scaffolding Protein; Signal Transduction; Signal Transduction Pathway; Stem cells; Surface; System; TCF Transcription Factor; Testing; Therapeutic; Tissues; Tretinoin; Wnt proteins; aqueous; cell type; fatty acylation; gel electrophoresis; member; morphogens; mutant; nanoparticle; nanoscale; novel; particle; protein function; public health relevance; receptor; self-renewal; stem cell fate; stem cell therapy

DESCRIPTION (provided by applicant): Stem cells hold great therapeutic promise for a variety of diseases. These cells are unique in that they are capable of self-renewal or differentiation into various tissue cell types. Factors that regulate the ultimate fate of stem cells include members of the Wnt protein family. Wnt proteins function by binding to cell surface receptors of the frizzled and low-density lipoprotein receptor-related protein families. Following binding, a signal is transduced to ss-catenin, which then enters the nucleus and forms a complex with T cell factor / lymphoid enhancer factor, activating transcription of Wnt target genes. The goal of proposed research is to generate a soluble, active Wnt protein for use in studies of signaling and stem cell self-renewal. In Aim 1 it is hypothesized that nanoscale bilayer disk particles, termed nanodisks (ND), will provide a lipid surface for Wnt fatty acyl chain insertion, thereby anchoring Wnt to the particle in a biologically active conformation. In Aim 2 it is hypothesized that Wnt3a-ND will possess biological activity in signal transduction and colony forming cell assays using hematopoietic stem cells. The hypothesis that inclusion of apolipoprotein E as ND scaffold protein will affect Wnt3a-ND activity through binding to the Wnt co-receptor LRP5 will be tested. The effect of including all trans retinoic acid as a component of Wnt3a-ND will be evaluated to determine if additive or synergistic stem cell self renewal activity will be observed. Execution of these studies will provide new results on a potential aqueous soluble Wnt3a binding complex that preserves the potent biological activity of members of this protein family. Defining conditions to induce expansion of HSC will have profound effects on disease treatment options and outcomes. PUBLIC HEALTH RELEVANCE: Stem cells hold exceptional promise as therapy for disease. A critical aspect related to the application of stem cells for therapy is an ability to regulate their fate, in terms of differentiation versus proliferation. An important signal transduction pathway involved in stem cell regulation is mediated by the "Wnt" protein. Studies to be undertaken will establish an optimized Wnt signaling system and evaluate stem cell responsiveness as a function Wnt association with specialized nanoparticles.

描述（由申请人提供）：干细胞对多种疾病有很大的治疗前景。这些细胞是独特的，因为它们能够自我更新或分化成各种组织细胞类型。调节干细胞最终命运的因子包括Wnt蛋白家族的成员。Wnt蛋白通过与卷曲蛋白和低密度脂蛋白受体相关蛋白家族的细胞表面受体结合而发挥功能。结合后，信号被转导至β-连环蛋白，其然后进入细胞核并与T细胞因子/淋巴增强因子形成复合物，激活Wnt靶基因的转录。拟议研究的目标是产生一种可溶性的活性Wnt蛋白，用于信号传导和干细胞自我更新的研究。在目的1中，假设纳米级双层盘颗粒（称为纳米盘（ND））将提供用于Wnt脂肪酰基链插入的脂质表面，从而将Wnt以生物活性构象锚定到颗粒。在目的2中，假设Wnt 3a-ND将在使用造血干细胞的信号转导和集落形成细胞测定中具有生物活性。将测试包含载脂蛋白E作为ND支架蛋白将通过与Wnt共受体LRP 5结合而影响Wnt 3a-ND活性的假设。将评估包括全反式视黄酸作为Wnt 3a-ND的组分的效果，以确定是否将观察到加和或协同干细胞自我更新活性。这些研究的执行将提供关于潜在的水溶性Wnt 3a结合复合物的新结果，该复合物保留了该蛋白质家族成员的有效生物活性。确定条件诱导HSC的扩增将对疾病的治疗选择和结果产生深远的影响。 公共卫生相关性：干细胞作为疾病的治疗方法具有特殊的前景。与用于治疗的干细胞的应用相关的关键方面是在分化与增殖方面调节其命运的能力。参与干细胞调节的重要信号转导途径是由“Wnt”蛋白介导的。将要进行的研究将建立一个优化的Wnt信号系统，并评估干细胞的反应性作为Wnt与专门的纳米颗粒的功能。