ALDH Activation to treat Fanconi Anemia

激活 ALDH 治疗范可尼贫血

• 批准号: 10178078
• 负责人: DARIA MOCHLY-ROSEN
• 金额: $ 48.26万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-15 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10178078
• 关键词: Acetaldehyde; Address; Affect; Age; Alcohol dehydrogenase; Alcohols; Aldehydes; Alleles; Aplastic Anemia; Asians; CCL3 gene; CRISPR/Cas technology; Cell Count; Cells; Chemotherapy and/or radiation; Child; Clinical; Clinical Trials; Complement; Complex; Congenital Abnormality; Cytoprotection; DNA Damage; DNA Interstrand Cross-Link Repair; DNA Interstrand Crosslinking; DNA Repair; DNA Repair Pathway; Development; Disadvantaged; Disulfiram; Effectiveness; Engraftment; Environment; Enzyme Stability; Enzymes; Ethanol; Ethanol Metabolism; Exposure to; FANCD2 protein; Failure; Family; Family member; Fanconi Anemia pathway; Fanconi' s Anemia; Far East; Fluorescence; Flushing; Food; Functional disorder; Gene Expression; Gene Expression Profile; Generations; Genes; Genetic Diseases; Genome; Genome Stability; Genomics; Genotype; Goals; Grant; Hematology; Hematopoiesis; Hematopoietic; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Human; Impairment; Individual; Ingestion; Inhalation; Injury; Interferons; Isoenzymes; K-562; K562 Cells; Knock-in; Knock-out; Link; Maintenance; Malignant Neoplasms; Malignant neoplasm of esophagus; Marrow; Measures; Mediating; Metabolism; Mus; Mutant Strains Mice; Mutate; Mutation; Oxides; Pancytopenia; Pathway interactions; Patients; Pattern; Pharmaceutical Preparations; Phenotype; Plants; Point Mutation; Predisposition; Prevention; Protein Family; Retinaldehyde; Second Primary Cancers; Single Nucleotide Polymorphism; Somatic Cell; Substrate Specificity; Syndrome; Testing; Tissues; Toxic effect; Translating; alcohol exposure; aldehyde dehydrogenases; base; cell injury; congenital anomaly; crosslink; enzyme activity; exhaustion; genotoxicity; high risk; in vitro Model; in vivo; insight; leukemia; loss of function; mortality; mouse model; mutant; novel; oxidation; palliative; post-transplant; preclinical study; prevent; protective effect; radiation risk; recruit; response; sensor; small molecule; stem cell population; stem cell self renewal

PROJECT SUMMARY Fanconi anemia (FA) is caused by mutations in one of at least 19 FA complementation (FANC) group genes, which are required to repair DNA interstrand cross links (ICL). Patients with FA have congenital anomalies, hematopoietic stem cell (HSC) injury resulting in increased susceptibility to bone marrow failure (severe aplastic anemia: SAA) and leukemia, increased sensitivity to chemotherapy and radiation, and high risk of secondary cancers, even if they are successfully treated by HSC transplantation for their aplastic anemia or leukemia. Because the mutations underlying FA affect every cell in the body, there is currently no cure for FA. Recent studies have demonstrated that ICL are caused by reactive aldehydes, such as acetaldehyde (MeCHO). Oxidation by the aldehyde dehydrogenase (ALDH) family of enzymes detoxify aldehydes. In East Asia, a highly prevalent point mutation in the Aldehyde Dehydrogenase 2 (ALDH2) gene causes a semidominant loss of function, and decreased ability to oxidize highly reactive MeCHO. Exposure to MeCHO occurs through generation by endogenous pathways, exogenous ingestion or inhalation, or as the major product of ethanol (EtOH) metabolism. The ALDH2*2 mutation results in the well-known “Asian flushing syndrome” marked by a disulfiram-like response to ingestion of small amounts of EtOH. The ALDH2*2 mutation also results in increased susceptibility to cancer, especially esophageal cancer. Thus, the ALDH2 and FA DNA repair pathways confer two tiers of genome protection from the toxic effects of MeCHO. Humans and mice doubly mutated for both pathways rapidly develop bone marrow failure due to the loss of HSC. Our analyses of mice with a knock-in of the human ALDH2*2 mutation at the murine ALDH2 allele show that, even in a basal environment, (without exposure to EtOH) HSC are 1) progressively lost, 2) at a competitive disadvantage to normal HSC, and 3) have a gene expression profile typical of a response to interferons, which are known inhibitors of stem cell self-renewal. Preliminary results also indicate that EtOH exposure causes significant decline in HSC numbers in wildtype (ALDH2*1/*1) mice. We have developed ALDH activators (Aldas), small molecules which increase the activity of both ALDH2*1 and ALDH2*2, or re-direct other ALDH family members, e.g., ALDH3a1, to also oxidize MeCHO. To measure the cellular aldehydic load, we have also made unique fluorescence based sensors, which can be used in flow cytometric analyses of individual cells, e.g., HSC. In this grant we will test the hypothesis that Aldas can protect FA HSC from genotoxic injury by decreasing the load of reactive aldehydes. We will study murine models doubly mutated for FANCD2 and ALDH2*2 to determine the protective effect of ALDH2 activation, measure the effects of Aldas on aldehydic load in HSC, and determine whether recruitment of ALDH3a1 to MeCHO metabolism protects HSC. These pre-clinical studies have the potential to rapidly translate to much needed clinical trials aimed at prevention of SAA, leukemia and cancer in patients with FA.

项目摘要 范可尼贫血（FA）是由至少19个FA互补（FANC）组基因之一的突变引起的， 其是修复DNA链间交联（ICL）所必需的。FA患者有先天性异常， 造血干细胞（HSC）损伤导致对骨髓衰竭（严重的 再生障碍性贫血（SAA）和白血病，对化疗和放疗的敏感性增加， 继发性癌症，即使他们通过HSC移植成功治疗了再生障碍性贫血或 白血病由于FA的突变会影响体内的每一个细胞，因此目前还没有治愈FA的方法。 近年来的研究表明，ICL是由乙醛等活性醛类化合物引起的 （MeCHO）。通过醛脱氢酶（ALDH）家族的酶的氧化使醛解毒。在东 在亚洲，乙醛脱氢酶2（ALDH 2）基因中的一种高度流行的点突变导致了一种 半显性功能丧失，以及氧化高活性MeCHO的能力降低。暴露于甲醇 通过内源性途径、外源性摄入或吸入产生，或作为主要的 乙醇（EtOH）代谢产物。ALDH 2 *2突变导致了众所周知的“亚洲潮红”， 以摄入少量乙醇的双硫仑样反应为特征的“综合征”。ALDH 2 *2 突变还导致对癌症，特别是食道癌的易感性增加。因此，ALDH 2和 FA DNA修复途径赋予两层基因组保护免受MeCHO的毒性作用。人类和 由于HSC的丧失，两种途径双重突变的小鼠迅速发展成骨髓衰竭。我们 对小鼠ALDH 2等位基因敲入人ALDH 2 *2突变的小鼠的分析表明，即使如此， 在基础环境中，（不暴露于EtOH）HSC 1）逐渐丧失，2）在竞争性 对正常HSC不利，和3）具有对干扰素应答的典型基因表达谱， 是已知的干细胞自我更新的抑制剂。初步结果还表明，EtOH暴露导致 在野生型（ALDH 2 *1/*1）小鼠中HSC数量显著下降。我们开发了ALDH激活剂 （Aldas），增加ALDH 2 *1和ALDH 2 *2两者的活性或重定向其它ALDH的小分子 家庭成员，例如，ALDH 3a 1，也氧化甲醇。为了测量细胞的生物负载，我们还 制造了独特的基于荧光的传感器，其可用于单个细胞的流式细胞术分析， 例如，在一个实施例中，HSC。在本研究中，我们将通过以下方法检验Aldas可以保护FA HSC免受遗传毒性损伤的假设： 降低反应性醛的负荷。我们将研究FANCD 2双重突变的小鼠模型， ALDH 2 *2，以确定ALDH 2激活的保护作用，测量Aldas对糖尿病的影响。 在HSC中加载，并确定ALDH 3a 1募集到MeCHO代谢是否保护HSC。这些 临床前研究有可能迅速转化为急需的临床试验，旨在预防 FA患者的SAA、白血病和癌症。