Molecular mechanisms for bone marrow failure and clonal progression during the innate immune response in Fanconi Anemia

范可尼贫血先天免疫反应期间骨髓衰竭和克隆进展的分子机制

基本信息

批准号：
10348140
负责人：
Elizabeth Ann Eklund
金额：
$ 35.57万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2024-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10348140
关键词：
ATR checkpoint Adjuvant Adverse effects Anemia Antigens Apoptosis Bone Marrow Bone Marrow Cells Bone Marrow Stem Cell Transplantation Bone marrow failure CD34 gene CSF3 gene Candida Cell Cycle Cell Cycle Arrest Cell Cycle Checkpoint Cells Cessation of life Childhood Chronic Clonal Expansion Complement Complication Congenital Disorders DNA DNA Damage DNA Repair DNA Repair Pathway DNA replication fork Disease Dysplasia Emergency Situation Erythroid Event Fanconi&apos s Anemia Functional disorder Gene Expression Genes Genetic Models Genetic Transcription Genotoxic Stress Goals Granulopoiesis Hematopoiesis Hematopoietic Hereditary Disease Human Infection Inflammation Inherited Injections Innate Immune Response Interleukin-1 Interleukin-1 beta Interruption Lead Mediating Molecular Morbidity - disease rate Mus Mutagenesis Mutation Myelogenous Myeloid Leukemia NADPH Oxidase Pancytopenia Pathway interactions Patients Phagocytes Process Production Reactive Oxygen Species Recurrence Regulatory Pathway Resistance Role S phase Signal Transduction Stimulus Stress Survivors TP53 gene Testing Therapeutic Wild Type Mouse adverse outcome aluminum sulfate antagonist crosslink cytokine density granulocyte granulocyte-monocyte progenitors hematopoietic stem cell expansion leukemia mortality mouse model novel pathogen preclinical study prevent progenitor repaired response screening small molecule inhibitor stem stem cells transcription factor translational potential

项目摘要

The Fanconi DNA repair pathway is required for rescue of stalled or collapsed replication forks. Fanconi Anemia (FA) is caused by inherited mutation of Fanconi genes. FA patients develop bone marrow failure (BMF) in childhood, with survivors frequently developing clonal progression. We identified a role for emergency (stress) granulopoiesis (EG) in BMF and clonal progression in FA. EG is an episodic process for granulocyte production in response to infectious challenge. During EG, S phase is shortened and FancC and F expression increase. Unlike wild type mice, Fancc-/- mice did not develop granulocytosis upon stimulation of EG. Repeated EG challenge in Fancc-/- mice induced either BMF, with apoptosis of HSC and progenitors, or clonal progression. Treatment of Fancc-/- mice with an IL1-R antagonist protected them from these adverse consequences. IL1β is an essential cytokine for EG; inducing myeloid lineage commitment, and G-CSF expression. During the S phase, Atr activates p53 and apoptosis of cells with unrepaired replication fork damage. In Fancc-/- mice, Tp53-haplo- insufficiency rescued granulocytosis during EG; delaying BMF but accelerating clonal progression. In Fancc-/- mice, increasing activity of Atr/p53 occurred with each unsuccessful EG episode; associated with BMF. In contrast, Atr/p53 activity decreased with consecutive, successful EG cycles in Fancc-/-Tp53+/- mice. We hypothesize unsuccessful PMN production in FA during EG prevents activation of unknown negative regulatory pathways; sustaining cell cycle checkpoint activity and HSC/GMP expansion signals. This induces BMF and accumulation of mutations that lead to clonal progression. We will pursue this through three aims: Aim 1: Define molecular triggers for termination of emergency granulopoiesis and the role of this process in BMF in FA. We will investigate contribution of PMN density to apoptosis and BMF during unsuccessful EG in Fancc-/- mice. The impact of PMN bone marrow density on known EG-related pathways will be determined in Wt vs Fancc-/- mice, and novel pathways identified in non-biased studies. Aim 2: Identify events associated with emergency granulopoiesis-induced clonal progression in FA. We will define events involved in clonal progression in Fancc-/- mice by studying leukemia suppressor pathways that mediate EG termination and by non-biased approaches. Results will be compared to gene expression profiles in CD34+ bone marrow cells from human Fanconi Anemia to identify potential translational targets. Aim 3: Investigate potential translational targets to delay BMF or clonal progression in FA. We will determine the impact of novel pathways that are activated during EG on BMF and/or clonal progression in murine genetic models. Relevant intermediates with small molecule inhibitors will be tested in pre-clinical studies. The goal of these studies is to define molecular mechanisms for BMF and/or clonal progression during recurrent, unsuccessful EG attempts in FA. This may suggest therapeutic approaches to decrease morbidity due to anemia and infection, or bridge patients to definitive treatments such as stem cell/bone marrow transplant.

Fanconi DNA修复途径是挽救失速或折叠复制叉所必需的。 Fanconi 贫血（FA）是由Fanconi基因的遗传突变引起的。 FA患者发生骨髓衰竭（BMF）在童年时期，生存经常发展克隆进展。我们确定了紧急情况的作用（压力） BMF中的颗粒（例如）和Fa中的克隆进展。例如，是粒细胞生产的情节过程回应传染性挑战。在EG期间，S相缩短，FANCC和F表达增加。与野生型小鼠不同，FANCC - / - 小鼠在刺激EG时不会出现肉芽细胞增多症。重复EG FANCC - / - 小鼠的挑战诱导了BMF，HSC和祖细胞的凋亡或克隆进展。用IL1-R拮抗剂治疗FANCC - / - 小鼠免受这些不良后果的影响。 IL1β是 EG的必需细胞因子；诱导髓样谱系承诺和G-CSF表达。在s阶段， ATR用未修复的复制叉损伤激活细胞的p53和细胞凋亡。在fancc - / - 小鼠中，tp53-haplo- EG期间营救了粒细胞增多症；延迟BMF，但加速克隆进展。在fancc - / - 小鼠，每个失败的EG发作都会发生ATR/p53的活动越来越多；与BMF相关。在对比度，ATR/p53活性随FANCC - / - TP53 +/-小鼠的连续，成功的EG周期而降低。我们假设在EG期间，FA中的PMN产生不成功监管途径；维持细胞周期检查点活性和HSC/GMP扩展信号。这会引起 BMF和导致克隆进展的突变的积累。我们将通过三个目标来追求这一点： AIM 1：定义分子触发因素以终止紧急粒状及其作用在FA中的BMF中的过程。我们将研究PMN密度对凋亡和BMF的贡献 FANCC - / - 小鼠中的失败。 PMN骨髓密度对已知EG相关途径的影响将在wt vs fancc - / - 小鼠中确定，在非偏见研究中确定的新途径。 AIM 2：确定与紧急颗粒诱导的FA克隆进展相关的事件。我们将通过研究白血病抑制途径来定义fancc-/ - 小鼠中克隆进展的事件通过介导EG终止和非偏见的方法。结果将与基因表达进行比较 CD34+骨髓细胞中的曲线均来自人类的fanconi贫血，以鉴定潜在的翻译靶标。 AIM 3：研究潜在的翻译目标，以延迟FA中BMF或克隆进展。我们将确定EG在BMF和/或鼠中的克隆进展中激活的新型途径的影响遗传模型。与小分子抑制剂相关的中间体将在临床前研究中进行测试。这些研究的目的是定义BMF和/或克隆进展的分子机制经常性，不成功的例如在FA中尝试。这可能表明热方法可降低应有的发病率致贫血和感染，或将患者桥接到明确治疗，例如干细胞/骨髓移植。