Animal Models of Polycythemia Vera

真性红细胞增多症的动物模型

• 批准号: 8064161
• 负责人: Jerry L Spivak
• 金额: $ 49.57万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2015-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8064161
• 关键词: Acute leukemia; Alleles; Animal Model; Behavior; Biological Models; Blood Cells; Blood Platelets; Breeding; CD34 gene; Candidate Disease Gene; Cell Transplantation; Cells; Characteristics; Clinical; Commit; Companions; Crossbreeding; Development; Disease; Exons; Fibrosis; Frequencies; Functional disorder; Gene Expression; Gene Expression Profile; Gene Expression Profiling; Genes; Genetic Techniques; Genotype; Hematopoietic stem cells; Hemorrhagic Thrombocythemia; Human; Immune Sera; Indolent; JAK2 gene; Knock-out; Laboratories; Link; MPL gene; Marrow; Megakaryocytes; Modeling; Molecular; Mus; Mutation; Myeloproliferative disease; Orthologous Gene; Pathogenesis; Patients; Phenotype; Phosphotransferases; Plasma; Point Mutation; Polycythemia Vera; Primary Myelofibrosis; Process; Production; Progress Reports; Proteins; RNA Splicing; Research; Research Design; Research Project Grants; Role; Stem cells; Surface; THPO gene; Testing; Thrombopoietin; Thrombosis; Transgenic Mice; Transgenic Model; Variant; Xenograft procedure; base; clinical phenotype; extracellular; genetic manipulation; human MPL protein; in vivo; in vivo Model; knockout gene; mouse model; mutant; patient population; peripheral blood; research study; thrombocytosis

The long-temri objective of this research project is to define the molecular basis of polycythemia vera (PV). PV represents the ultimate phenotype of the mutant kinase, JAK2 V617F, through its effects on committed hematopoietic progenitor cells but we hypothesize that while JAK2 V617F expression is responsible for the clinical phenotype of PV, the underlying molecular mechanisms responsible for the disease reside in the hematopoietic stem cell (HSC), which does not require JAK2, and that the thrombopoietin (TPO) receptor, Mpl, is integrally Involved In these mechanisms. This hypothesis, which is based on our discovery of impaired Mpl expression in PV with an attendant increase in plasma TPO, and our observation that absence of the MPL gene abrogated the PV phenotype in a JAK2 V617F transgenic (tg) mouse model of PV, provides a mechanistic basis for understanding the pathophysiology of PV at the stem cell level and a rational approach to therapy To this end, we propose to use genetic techniques to dissect the influence of the MPL:TPO axis, and also the roles of specific genes up regulated in human PV CD34+ cells, on the behavior of HSC in the murine JAK2 V617F tg model of PV. In Specific Aim 1, we will examine the effect of abrogation of the TPO gene on the phenotype of the JAK2 V617F tg mouse, on the size of its HSC pool and the HSC gene expression profile, by breeding with a TPO-/- mouse. Control experiments will employ mice in which Mpl function was abrogated by a point mutation or a gene knockout independent of MPL that impairs platelet production, while a neutralizing Mpl antiserum will be examined as a model of targeted therapy. In Specific Aim 2, we will create a tg mouse expressing a PV Mpl splice variant and assess its phenotype in the presence and absence of JAK2 V617F. We also examine by crossbreeding, the effect of knocking out SPARC or LCN2, two genes that are up regulated in PV, on the phenotype of the JAK2 V617F tg mouse. Finally, in Specific Aim 3, we will use xenotranslantation in NOG mice to examine the in vivo behavior of genetically-defined PV CD34 + cells from clinically distinct PV patient populations that we have identified by gene expression profiling and unsuoervised hierarchical clustering.

该研究项目的长期目标是确定真性红细胞增多症 (PV) 的分子基础。 PV 代表突变激酶 JAK2 V617F 的最终表型，通过其对定型造血祖细胞的影响，但我们假设，虽然 JAK2 V617F 表达是导致 PV 临床表型的原因，但导致该疾病的潜在分子机制在于 造血干细胞 (HSC) 不需要 JAK2，而血小板生成素 (TPO) 受体 Mpl 整体参与这些机制。这一假设基于我们发现 PV 中 Mpl 表达受损并伴随血浆 TPO 增加，以及我们观察到缺乏 MPL基因的研究消除了JAK2 V617F转基因（tg）PV小鼠模型中的PV表型，为在干细胞水平上理解PV的病理生理学和合理的治疗方法提供了机制基础。为此，我们建议使用遗传技术来剖析PV表型的影响 MPL:TPO 轴以及人 PV CD34+ 细胞中上调的特定基因对小鼠 JAK2 V617F tg PV 模型中 HSC 行为的作用。在具体目标 1 中，我们将检查 TPO 基因的废除对 JAK2 V617F tg 小鼠表型、其 HSC 池大小和 HSC 的影响 基因表达谱，通过与 TPO-/- 小鼠繁殖。对照实验将使用小鼠，其中 Mpl 功能因点突变或独立于 MPL 的基因敲除而被消除，从而损害血小板生成，同时将检查中和 Mpl 抗血清作为靶向治疗的模型。具体来说 目标 2，我们将创建表达 PV Mpl 剪接变体的 tg 小鼠，并评估其在存在和不存在 JAK2 V617F 的情况下的表型。我们还通过杂交检查敲除 SPARC 或 LCN2（PV 中上调的两个基因）对 JAK2 V617F tg 小鼠表型的影响。 最后，在具体目标 3 中，我们将在 NOG 小鼠中使用异种移植来检查来自临床不同 PV 患者群体的基因定义的 PV CD34 + 细胞的体内行为，我们已通过基因表达谱和无监督的层次聚类鉴定了这些患者群体。