Regulation of protein ubiquitination in hematopoietic cytokine signaling

造血细胞因子信号传导中蛋白质泛素化的调节

基本信息

批准号：
9310835
负责人：
Wei Tong
金额：
$ 56.7万
依托单位：
CHILDREN'S HOSP OF PHILADELPHIA
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-04-18 至 2021-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9310835
关键词：
Acute Myelocytic Leukemia Adaptor Signaling Protein Address Alleles Attenuated Automobile Driving Biochemical Blood Cells Bone Marrow Transplantation CBL Protein CBL gene Cell Count Cell Line Cell Proliferation Cells Chronic Clonal Hematopoietic Stem Cell Collaborations Cytokine Receptors Cytokine Signaling Data Development Disease Disease remission Engineering Exhibits FDA approved Family Frequencies Genetic Goals Granulocyte-Macrophage Colony-Stimulating Factor Receptors Growth Half-Life Hematopoiesis Hematopoietic Hematopoietic Neoplasms Hematopoietic stem cells Homeostasis Human Hypersensitivity Interleukin-3 Janus kinase Janus kinase 2 Juvenile Myelomonocytic Leukemia Kinetics Knock-in Mouse Knock-out Knockout Mice MPL gene Malignant - descriptor Mediating Modeling Molecular Molecular Conformation Mus Mutation Myelogenous Myeloproliferative disease Patients Pharmacology Phenocopy Phosphorylation Phosphotransferases Play Protein Tyrosine Kinase Proteins Proteomics Regulation Role Series Signal Pathway Signal Transduction Site Stem cell transplant Stem cells Testing Therapeutic Tyrosine Ubiquitin Ubiquitination Ursidae Family Viral actionable mutation cell growth cytokine gain of function human stem cells in vivo induced pluripotent stem cell insight kinase inhibitor loss of function mutation mouse model mutant novel novel therapeutics outcome forecast overexpression patient population progenitor receptor therapeutic target treatment strategy ubiquitin-protein ligase

项目摘要

Abstract Hematopoietic stem and progenitor cell (HSPC) homeostasis is regulated by intricate cytokine receptor and tyrosine kinase signaling pathways. Janus Kinase 2 (JAK2) is the key tyrosine kinase in the signaling pathway of an array of hematopoietic receptors, including thrombopoietin (TPO) receptor (MPL) in hematopoietic stem cells (HSCs) and granulocyte macrophage colony-stimulating factor receptor (GM-CSFR) in myeloid progenitors. While JAK2 plays an essential role in hematopoietic development, uncontrolled JAK2 signaling results in hematopoietic malignancies. Gain-of-function JAK2 mutations such as V617F are found in large populations of patients with myeloproliferative neoplasms (MPNs), a clonal HSC disease. Genetically targeting JAK2 abrogates MPN in mice; the JAK2V617F mutation is the driving mutation found in the HSCs of human MPN patients. However, current FDA-approved JAK kinase inhibitors have low curative potential, indicating the need for a better understanding of the regulation of JAK2 for efficient targeting. A number of E3 ubiquitin ligases for JAK2 have been proposed, but none of them, when lost in vivo, increases JAK2 protein level in HSPCs, expands HSC pool, or enhances multiple lineage hematopoiesis. Thus, the E3 ligase(s) regulating JAK2 turnover remain elusive. Through a series of biochemical and functional studies, we found that JAK2 stability is regulated by the CBL family E3 ubiquitin ligases, c-CBL and CBL-b, via the adaptor protein LNK (also called SH2B3). C-Cbl-/- mice phenocopy Lnk-/- mice, exhibiting an augmented HSPC pool with superior transplantability and hypersensitivity to cytokines. Importantly, CBL loss-of-function mutations have been found in a wide range of myeloid malignancies with the most frequent occurrence in chronic and juvenile myelomonocytic leukemia (CMML and JMML), both of which bear poor prognosis. Here, we propose to define the molecular basis underlying the regulation of JAK2 stability and signaling through this novel signaling axis, CBL/LNK/JAK2, and exploit it for therapeutic strategies in treating myeloid neoplasms. The following specific aims will be addressed: 1. Investigate mechanisms by which CBL regulates JAK2 ubiquitination, stability and signaling in hematopoietic cell lines and HSPCs from Cbl deficient and Cbl E3 ligase inactive mouse models. 2. Determine the influence of CBL on the stability of constitutively active JAK2 mutants and mutant JAK2- mediated MPN development. 3. Determine the role of CBL in regulating JAK2 level and signaling in primary human progenitors and explore therapeutic potential of JAK inhibition in treating murine and human myeloid malignancies with CBL mutations. Collectively, our data point to a novel direct role of CBL-mediated JAK2 ubiquitination and degradation in cytokine signaling and hematopoiesis. The proposed studies will likely provide mechanistic insights into the regulation of wild type JAK2 in normal HSPCs as well as JAK2 mutants in MPNs. In addition, our studies may reveal novel therapeutic strategies for the treatment of CBLmut myeloid malignancies with poor prognosis.

抽象的造血干和祖细胞（HSPC）稳态受到复杂的细胞因子受体和酪氨酸激酶信号通路。 Janus激酶2（JAK2）是信号通路中的关键酪氨酸激酶一系列造血受体，包括造血茎中的血小板素（TPO）受体（MPL）细胞（HSC）和粒细胞巨噬细胞刺激因子受体（GM-CSFR）祖先。虽然JAK2在造血发育中起着至关重要的作用，但不受控制的JAK2信号传导导致造血恶性肿瘤。在大型中发现了功能的JAK2突变（例如V617F）克隆HSC疾病的骨髓增生性肿瘤（MPN）患者的种群。遗传靶向 JAK2废除了小鼠的MPN； JAK2V617F突变是在人MPN的HSC中发现的驱动突变患者。但是，当前经FDA批准的JAK激酶抑制剂具有较低的治疗潜力，表明需要为了更好地了解JAK2的调节，以进行有效的靶向。许多E3泛素连接酶已经提出了JAK2，但是当体内丢失时，没有一个会增加HSPC中的JAK2蛋白水平，扩展HSC池或增强多个谱系造血。因此，调节JAK2的E3连接酶营业额仍然难以捉摸。通过一系列的生化和功能研究，我们发现JAK2稳定性是由CBL家族E3泛素连接酶，C-CBL和CBL-B调节，通过衔接蛋白LNK（也称为 SH2B3）。 c-cbl - / - 小鼠表液LNK - / - 小鼠，表现出具有上等的增强的HSPC池对细胞因子的移植性和超敏反应。重要的是，发现CBL功能丧失突变在各种髓样恶性肿瘤中，在慢性和少年中最常见脊髓细胞性白血病（CMML和JMML）的预后不佳。在这里，我们建议定义通过这个新型信号轴调节JAK2稳定性和信号传导的分子基础， CBL/LNK/JAK2，并利用它来治疗髓样肿瘤的治疗策略。以下特定目标将被解决：1。调查CBL调节JAK2泛素化，稳定性和来自CBL缺乏和CBL E3连接酶无活性小鼠模型的造血细胞系和HSPC中的信号传导。 2。确定CBL对组成型活性JAK2突变体和突变体Jak2-的稳定性的影响介导的MPN开发。 3。确定CBL在调节JAK2水平和信号中的作用人类祖细胞并探索JAK抑制在治疗鼠和人髓样中的治疗潜力 CBL突变的恶性肿瘤。总的来说，我们的数据指向CBL介导的JAK2的新型直接作用细胞因子信号传导和造血的泛素化和降解。拟议的研究可能会提供有关正常HSPC和JAK2突变体的野生型JAK2调节的机械洞察力 MPN。此外，我们的研究可能揭示了治疗CBLMUT髓样的新型治疗策略预后不良的恶性肿瘤。