Role of autophagy in normal and transformed hematopoietic stem cells

自噬在正常和转化造血干细胞中的作用

基本信息

批准号：
8827732
负责人：
Emmanuelle Passegue
金额：
$ 35.75万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-01 至 2019-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8827732
关键词：
Address Affect Autophagocytosis Biochemical Biological Preservation Biology Blood Blood Cells Bone Marrow Cell Maintenance Cell Respiration Cell physiology Cells Chemicals Chronic Myeloid Leukemia Chronic-Phase Myeloid Leukemia Dependency Development Disease Eating Ensure Food deprivation (experimental)Garbage Gene Expression Genes Genetic Genome Stability Goals Health Hematologic Neoplasms Hematological Disease Hematopoiesis Hematopoietic stem cells Homeostasis Human Hypoxia Investigation Leukemic Hematopoietic Stem Cell Life Lysosomes Maintenance Malignant - descriptor Mediating Metabolic Metabolic stress Molecular Chaperones Molecular Target Mus Myelogenous Myeloproliferative disease Organelles PI3K/AKT Pathogenesis Pathway interactions Prevention Process Production Proteins Protocols documentation Reactive Oxygen Species Regulation Resistance Role Signal Transduction Staging Stem Cell Development Stem cells Stress System Therapeutic Tyrosine Kinase Inhibitor Vesicle Withdrawal bcr-abl Fusion Proteins biological adaptation to stress cell transformation coping cytokine genetic approach granulocyte in vivo inhibitor/antagonist insight leukemia macrophage microbial mouse model novel progenitor programs response self-renewal stem cell biology stem cell therapy targeted treatment therapy resistant trafficking transcription factor ward

项目摘要

DESCRIPTION (provided by applicant): The overall goal of this application is to understand how autophagy supports the maintenance and function of blood-forming hematopoietic stem cells (HSC), and how corruption of this stress-response mechanism in transformed HSCs contributes to the development of myeloid malignancies such as chronic myelogenous leukemia (CML). We recently demonstrated that HSCs survive metabolic stress by inducing a robust protective autophagy response (Warr et al., 2013). In particular, we showed that the transcription factor FoxO3A is essential to maintain a pro-autophagy gene program that poises HSCs for rapid autophagy induction. However, how HSCs sense metabolic stress and activate autophagy is still unknown, and much remains to be understood about the role of autophagy in normal and transformed HSCs. We will use both pharmacological and genetic approaches to dissect the contribution of autophagy to HSC biology, and our established Scl- tTA:TRE-BCR/ABL (tTA-BA) mouse model of human chronic phase CML (Reynaud et al., 2011) to probe the function of autophagy in leukemia-initiating stem cell (LSC) activity and CML development. In Specific Aim 1, we will determine the mechanisms by which HSCs activate autophagy. We will use our established protocols to induce metabolic stress in HSCs ex vivo upon cytokine withdrawal and in vivo upon food deprivation, and will take advantage of existing genetic mouse models and chemical inhibitors to identify how HSCs sense metabolic stress and trigger autophagy induction. These approaches will establish how HSCs elicit a protective autophagy response upon metabolic challenges. In Specific Aim 2, we will address how loss of autophagy affects HSC function and genomic stability in vivo, and investigate whether alternative forms of protein and organelle turnover can support the long-term maintenance of autophagy-deficient HSCs. These approaches will delineate how autophagy is normally utilized by HSCs in vivo, and how its abrogation alters normal hematopoiesis. In Specific Aim 3, we will probe the function of autophagy in transformed BCR/ABL- expressing HSCs, and will take advantage of our inducible tTA-BA mouse model to investigate the contribution of autophagy to CML pathogenesis and response of CML LSCs to tyrosine kinase inhibitor (TKI) treatments. These approaches will provide important new insights into the mechanisms of malignant transformation in the blood system. They will elucidate the contribution of autophagy in HSC transformation and CML development, and determine how the autophagy machinery can be manipulated to achieve a therapeutic benefit. Taken together, these studies will uncover how corruption of an essential mechanism of cell preservation normally used by HSCs to maintain blood homeostasis contributes to the aberrant function of transformed HSCs and the development of blood diseases.

描述（由申请人提供）：本申请的总体目标是了解自噬如何支持造血造血干细胞（HSC）的维持和功能，以及这种转化的HSC中这种应激反应机制的腐败如何促进髓样性恶性肿瘤的发展，例如慢性髓质性白血病（CML）。我们最近证明，HSC通过诱导强大的保护性自噬反应来生存代谢应激（Warr等，2013）。特别是，我们表明转录因子FOXO3A对于维持一个促噬噬菌基因程序至关重要，该基因计划为快速自噬诱导而积聚HSC。但是，HSC如何感知代谢应力和激活自噬仍然未知，并且关于自噬在正常和转化的HSC中的作用还有很多待理解。我们将使用药理和遗传学方法来剖析自噬对HSC生物学的贡献，以及我们已建立的人类慢性相CML的SCL-TA：TRE-BCR/ABL/ABL/ABL（TTA-BA）小鼠模型（Reynaud等人，2011年），以探测白血病的功能在白血病中的功能（LSCINITIATIATS INTITINIT STEMITIATSINITINIT CYTER（LSC）。在特定目标1中，我们将确定HSC激活自噬的机制。我们将使用我们既定的方案在细胞因子戒断后和体内诱导HSC的代谢应激，并在食物剥夺后诱导体内，并利用现有的遗传小鼠模型和化学抑制剂来识别HSC如何感觉代谢应激并触发自噬诱导。这些方法将确定HSC如何在代谢挑战上引起保护性自噬反应。在特定的目标2中，我们将解决自噬的损失如何影响体内HSC功能和基因组稳定性，并研究蛋白质和细胞器更新的替代形式是否可以支持自噬缺陷HSC的长期维持。这些方法将描述HSC在体内通常如何利用自噬，以及其废除如何改变正常的造血。在特定的目标3中，我们将探测自噬在转化的BCR/ABL-表达HSC中的功能，并将利用我们诱导的TTA-BA小鼠模型来研究自噬对CML发病机理的贡献以及CML LSC对酪氨酸激酶抑制剂（TKI）处理的响应。这些方法将为血液系统中恶性转化的机制提供重要的新见解。他们将阐明自噬在HSC转化和CML开发中的贡献，并确定如何操纵自噬机械以获得治疗益处。综上所述，这些研究将发现HSC通常用于维持血液稳态的细胞保存基本机制的腐败如何有助于转化的HSC的异常功能和血液疾病的发展。