JAK2 signaling in erythropoiesis

红细胞生成中的 JAK2 信号传导

基本信息

批准号：
8512914
负责人：
LILY JUNSHEN HUANG
金额：
$ 37.84万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-09-01 至 2018-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8512914
关键词：
Affect Anemia Biology Blood Cells Blood Substitutes Catalytic Domain ChIP-seq Chromatin Structure Clinical Data Complex Cytokine Receptors Defect Development EZH2 gene Endocytosis Epigenetic Process Erythrocytes Erythrocytoses Erythroid Erythropoiesis Erythropoietin Receptor Etiology Event Exhibits Exons Feedback Functional disorder Funding Gene Expression Gene Targeting Generations Genetic Transcription Goals Granulopoiesis Hematologic Neoplasms Hematopoiesis Hematopoietic Human In Vitro Investigation Knowledge Ligands Light Mediating Modeling Molecular Mus Mutation Myeloproliferative disease Pathway interactions Patients Phenotype Phosphorylation Phosphorylation Site Phosphotransferases Play Polycomb Polycythemia Process Production Protein Tyrosine Kinase Proteins Recruitment Activity Regulation Repression Role STAT5A gene Signal Pathway Signal Transduction Stem cells System Testing Therapeutic Agents Toxic effect Translating Work chromatin immunoprecipitation design effective therapy epsin erythroid differentiation gain of function genome wide association study genome-wide granulocyte improved in vitro activity in vivo kinase inhibitor knowledge base mouse model mutant novel novel therapeutics progenitor public health relevance research study stem

项目摘要

DESCRIPTION (provided by applicant): The Janus tyrosine kinase 2 (JAK2) plays an important role in hematopoiesis of multiple lineages, and a gain-of-function JAK2 mutation, V617F, is the major determinant in myeloproliferative neoplasms (MPNs). JAK2 kinase inhibitors showed hematological toxicity in treating MPNs, calling for novel therapeutics that can target only the affected lineage while sparing others. This task is hampered by lack of understanding in how JAK2 signaling regulates the generation of different blood cells. We propose to fill this knowledge gap by determining JAK2 signaling pathways that differentially drive erythropoiesis vs. granulopoiesis, and delineate two novel pathways utilized by JAK2 to regulate signaling and transcription for erythroid differentiation. The overall goal of this proposl is to characterize mechanisms underlying how JAK2 regulates erythropoiesis. Aim 1 will characterize a novel set of murine models; each expresses a different activating JAK2 mutant that results in a distinct MPN phenotype. We will determine whether different JAK2 mutants cause erythrocytosis or granulocytosis by promoting lineage-specific proliferation or by skewing differentiation in common progenitor compartments, and identify downstream signaling pathways required therein to cause different MPN phenotypes. We will also translate these mechanistic studies into the human setting. Aims 2 and 3 will dissect two novel molecular mechanisms for JAK2 to orchestrate signaling and transcription for erythroid differentiation, and examine their contribution in MPN development. Aim 2 will use both in vitro and in vivo experiments to characterize how JAK2 directs endocytosis of the erythropoietin receptor to terminate signaling. This process involves a new function of the p85 subunit of PI3K and is PI3K kinase activity-independent. Defects in this process result in prolonged signaling in primary and familial congenital polycythemia. In Aim 3, we will employ transcriptional profiling and genome-wide chromatin-immunoprecipitation followed by high-throughput sequencing (ChIP-seq) to delineate a novel pathway whereby JAK2 controls transcription, not by the canonical JAK-STAT pathway, but by regulating chromatin structure through phosphorylating the polycomb repression complex 2. Results from these studies will fill key gaps in our understanding of signaling in hematopoietic stem and progenitor cells that regulate both normal and excessive erythropoiesis. These results will also further our understanding of how Epo signaling is terminated, and will shift the paradigm of how JAK2 activates erythroid transcriptional network. In addition, these results will shed light on MPN biology and facilitate the design of novel and more effective therapeutic agents that specifically target affected lineage without compromising other lineages.

描述（由申请人提供）：Janus酪氨酸激酶2（JAK2）在多个谱系的造血中起重要作用，并且功能良好的JAK2突变V617F是骨髓增生性肿瘤肿瘤（MPNS）的主要决定因素。 JAK2激酶抑制剂在治疗MPN中显示出血液学的毒性，呼吁新型治疗剂可以在保留其他人时仅针对受影响的谱系。由于缺乏对JAK2信号传导如何调节不同血细胞的产生，因此无法阻碍此任务。我们建议通过确定差异驱动红细胞生成与颗粒的JAK2信号通路来填补这一知识差距，并描述JAK2使用的两种新型途径，以调节红细胞分化的信号传导和转录。该提议的总体目标是表征JAK2如何调节红细胞生成的机制。 AIM 1将描述一组新型的鼠模型；每个表达了不同的激活JAK2突变体，从而导致不同的MPN表型。我们将确定不同的JAK2突变体是通过促进谱系特异性增殖而引起的红细胞增生或粒细胞增多症，还是通过偏分化共同祖细胞室的分化，并确定所需的下游信号传导途径在其中引起不同的MPN表型。我们还将这些机械研究转化为人类环境。 AIM 2和3将剖析JAK2的两种新型分子机制，以编排信号和转录以进行红系分化，并检查它们在MPN发育中的贡献。 AIM 2将同时使用体外和体内实验来表征JAK2如何指导促红细胞生成素受体的内吞作用以终止信号传导。该过程涉及PI3K的p85亚基的新功能，并且是PI3K激酶活性无关的。在此过程中的缺陷导致原发性和家族性多余毛细血管高的信号传导延长。在AIM 3中，我们将采用转录分析和全基因组染色质 - 免疫沉淀，然后进行高通量测序（CHIP-SEQ）来描述一种新的途径，从而可以控制JAK2，而不是通过规范JAK-STAT途径来控制转录，而是通过规范的JAK-STAT途径，而是通过通过phossermit glossermess in Indropers grops grops grops grops grops grops ropsiment grops grops ropsiment gropssign ryssigns进行了这些键合成，从而填充了这些键合的结果。造血干细胞和祖细胞均调节正常和过度的红细胞生成。这些结果还将进一步了解我们对EPO信号的终止方式，并将改变JAK2如何激活红系转录网络的范式。此外，这些结果将阐明MPN生物学，并促进新颖，更有效的治疗剂的设计，这些治疗剂专门针对受影响的谱系而不会损害其他谱系。