Mechanistic Studies and Translational Applications of Stress Signaling in Anemia

贫血中应激信号传导的机制研究和转化应用

基本信息

批准号：
9177621
负责人：
Joseph Anthony Garcia
金额：
$ 40.48万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2020-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9177621
关键词：
Ablation Acetate-CoA Ligase Acetates Acetyl Coenzyme A Acetylation Acetylesterase Acetyltransferase Acute Adult Affect Anemia Animals Appearance Biochemical Biological Blood Transfusion Bolus Infusion Cell Culture Techniques Cell Nucleus Cells Chronic Clustered Regularly Interspaced Short Palindromic Repeats Complex Cytosol Data Deacetylation Development Disease Enzymes Epithelial Cells Erythrocytes Erythropoiesis Erythropoietin Flare Fostering Gene Targeting Genes Goals Growth Health Care Costs Hemolytic Anemia Hepatocyte Hormones Hypertension Hypoxia Injection of therapeutic agent Intestines Iron Iron deficiency anemia Kidney Knockout Mice Knowledge Link Liver Lysine Malignant Neoplasms Mammalian Cell Mammals Mediating Medical Minor Modeling Modification Molecular Morbidity - disease rate Mouse Strains Mus Mutant Strains Mice Mutation Nuclear Nuclear Export Nuclear Localization Signal Nuclear Translocation Oxidative Stress Pathway interactions Patients Physiological Physiological Processes Process Production Recombinant Erythropoietin Renal Interstitial Cell Reporting Role Signal Transduction Stress Testing Therapeutic Intervention Thrombosis Tissues Venous absorption antioxidant enzyme bHLH-PAS factor HLF base biological adaptation to stress congenic cost hypoxia inducible factor 1 innovation insight iron supplement loss of function loss of function mutation member mortality mutant novel null mutation response transcription factor treatment strategy uptake

项目摘要

ABSTRACT Anemia is a common medical condition with significant morbidity and mortality, especially if present with other diseases. The development of recombinant Erythropoietin (Epo), a pro-erythrocyte hormone produced in adult kidney and liver during anemia, revolutionized anemia treatment. Unfortunately, non- physiological bolus Epo also promotes thrombosis, hypertension, and cancer growth. Furthermore, many anemia patients are iron deficient and require parenteral or intra-venous iron supplements, which are poorly tolerated. Endogenous Epo production and iron uptake are tightly controlled by the stress- responsive transcription factor Hypoxia Inducible Factor 2 (HIF-2). During hypoxia, HIF-2 undergoes cyclical acetylation/deacetylation modifications, which augment HIF-2 signaling. HIF-2 acetylation is rate-limiting and conferred selectively by the acetyltransferase Cbp. Acetylation of HIF-2 by Cbp is regulated by a specific acetyl CoA generator, acetate-dependent acetyl CoA synthetase 2 (Acss2), which normally is present in the cytosol. Acetate, whether generated endogenously in anemic mice or provided exogenously as a therapeutic intervention, functions as a biochemical flare to activate Cbp- mediated HIF-2 acetylation and is accompanied by the de novo appearance of nuclear Acss2. We hypothesize that acetate induces translocation of Acss2 from the cytosol to the nucleus, where it generates a specific acetyl CoA pool used by Cbp to acetylate HIF-2 and augment HIF-2 signaling. The goal of this proposal is to elucidate the mechanism and biological role for Acss2 in mammals. We will do so with three aims employing integrative molecular, cellular, and animal studies. First, we will identify the molecular basis for Acss2 nuclear localization using molecular and biochemical assessments in cell culture models. Second, we will assess how restricting Acss2 to the cytosol or changing the genetic background of an Acss2 null mutation through CRISPR-modified targeting or congenic breedings in mice, respectively, affects the erythropoietic response to anemia. Third, we will determine what effect cell-specific ablation of Acss2 has on molecular and physiological responses to acute anemia and iron uptake in mice. Deciphering how the acetate/Acss2 switch regulates HIF-2 signaling will provide key insights into a novel signal transduction mechanism. Defining its role in the mammalian response to anemia will foster innovative and economical treatment strategies for anemic patients, which may significantly reduce costs associated with current approaches.

抽象的贫血是一种常见的疾病，具有显着的发病率和死亡率，特别是如果存在的话与其他疾病。重组促红细胞生成素 (Epo)（一种促红细胞激素）的开发贫血期间在成人肾脏和肝脏中产生，彻底改变了贫血治疗。不幸的是，非生理推注 Epo 还会促进血栓形成、高血压和癌症生长。此外，许多贫血患者缺铁，需要肠外或静脉注射铁补充剂，这耐受性较差。内源性 EPO 的产生和铁的吸收受到应激的严格控制。反应性转录因子缺氧诱导因子 2 (HIF-2)。缺氧时，HIF-2 周期性乙酰化/脱乙酰化修饰，增强 HIF-2 信号传导。 HIF-2 乙酰化是限速并由乙酰转移酶 Cbp 选择性赋予。 Cbp 对 HIF-2 的乙酰化是由特定的乙酰 CoA 发生器、乙酸依赖的乙酰 CoA 合成酶 2 (Acss2) 调节，通常存在于细胞质中。乙酸，无论是贫血小鼠内源性产生还是外源提供作为治疗干预，作为生化耀斑来激活 Cbp- 介导的 HIF-2 乙酰化并伴随着核 Acss2 的从头出现。我们假设乙酸盐诱导 Acss2 从细胞质易位到细胞核，在那里它生成 Cbp 用来乙酰化 HIF-2 并增强 HIF-2 信号传导的特定乙酰 CoA 库。这该提案的目标是阐明 Acss2 在哺乳动物中的机制和生物学作用。我们将采用综合分子、细胞和动物研究来实现三个目标。首先，我们将使用分子和生物化学确定 Acss2 核定位的分子基础细胞培养模型的评估。其次，我们将评估如何将 Acss2 限制在细胞质或通过 CRISPR 修饰的靶向改变 Acss2 无效突变的遗传背景或小鼠的同类繁殖分别影响红细胞生成对贫血的反应。第三，我们将确定 Acss2 的细胞特异性消融对分子和生理反应有何影响小鼠急性贫血和铁摄取。解读醋酸酯/Acss2 开关如何调节 HIF-2 信号传导将为新的信号转导机制提供重要见解。定义其在哺乳动物对贫血的反应将促进贫血的创新和经济的治疗策略患者，这可能会显着降低与当前方法相关的成本。