Diversity Supplement to 2RO1 GM 099871

2RO1 GM 099871 的多样性补充

• 批准号: 9405952
• 负责人: Margaret Olive James
• 金额: $ 4.88万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9405952
• 关键词: 21 year old; Adolescent; Adult; Adverse drug effect; Adverse effects; Affect; Age; Alpha Cell; Animals; Anions; Binding Sites; Brain; Bromides; Catabolism; Cells; Child; Chlorides; Chronic; Clinical; Clinical Trials; Crystallization; Cytosol; Development; Dichloroacetate; Dichloroacetic Acid; Disease; Dose; Drug Kinetics; Energy Metabolism; Environmental Exposure; Enzymes; Exhibits; Extrahepatic; Frequencies; Genetic; Glutathione; Glutathione S-Transferase; Goals; Growth; Haplotypes; Heart; Hepatic; Human; Individual; Infant; Intestines; Investigational Drugs; Iodides; Isomerase; Kidney; Lactic Acidosis; Life; Link; Liver; Longevity; Metabolic; Metabolic Biotransformation; Metabolism; MicroRNAs; Mitochondria; Mitochondrial Matrix; Mitochondrial Proteins; Modeling; Nature; Oxidative Phosphorylation; PDH kinase; Pathway interactions; Pattern; Peripheral Nervous System Diseases; Pharmaceutical Preparations; Pharmacodynamics; Physiological; Play; Property; Proteins; Rattus; Recombinants; Research; Role; Salts; Sampling; Site; Solid Neoplasm; System; Therapeutic; Therapeutic Uses; Tissues; Transferase; Tyrosine; Variant; adduct; age difference; age related; aged; base; dechlorination; dehalogenation; genetic makeup; glyoxylate; individual patient; individualized medicine; inhibitor/antagonist; juvenile animal; knock-down; mRNA Expression; maleylacetone; pulmonary arterial hypertension; response

Project Summary. The broad, long-term objectives of this research are to understand the properties of glutathione transferase Z1 (GSTZ1) and its role in the elimination of the investigational drug dichloroacetic acid (DCA) across the human lifespan. This is important because while DCA, an inhibitor of mitochondrial pyruvate dehydrogenase kinase, has therapeutic benefits as a metabolic regulator in treating lactic acidosis, certain solid tumors and pulmonary arterial hypertension, it exhibits marked age- and genetics- related individual variability in pharmacokinetics that are linked to DCA's side effects. The first step in DCA metabolism is dechlorination to glyoxylate, catalyzed by GSTZ1. Also known as maleylacetoacetate isomerase, GSTZ1 plays an important physiological role in isomerizing endogenous reactive metabolites of the tyrosine catabolism pathway, maleylacetoacetate and maleylacetone. GSTZ1 is expressed chiefly in the liver, but also in kidney, intestine, brain and heart. It is the only enzyme known to catalyze the dehalogenation of DCA to its primary metabolite, glyoxylate. Although it is well recognized that DCA inhibits its own metabolism as well as that of its endogenous substrates, through inactivation of GSTZ1, the reasons for the marked individual variability in pharmacokinetics of DCA after repeated doses are only partially understood. Most adults clear repeated doses of DCA more slowly than children, and clearance is GSTZ1 haplotype dependent in children and adults. There is preliminary evidence that extrahepatic sites of DCA metabolism become of greater importance relative to liver following DCA treatment, and that this is age-dependent. Finally, chloride (Cl-) concentration affects the rate of inactivation of GSTZ1 by DCA in a haplotype-dependent manner; the much lower [Cl-] in mitochondria compared with cytosol is thought to be a factor in the more rapid inactivation of the mitochondrial matrix enzyme, and could be a factor in the observed age-dependent differences, as intracellular [Cl-] varies with age. The mechanism of how Cl- protects GSTZ1 from DCA-dependent inactivation is not known. This application seeks to examine reasons for age- and genetics- related changes in expression and activity of GSTZ1 in people. Three specific aims are proposed. The first specific aim will study the role of microRNA (miR) in regulating the documented age-related changes in hepatic GSTZ1 expression. This aim will use banked human liver of different aged donors to identify miRs, and cell-based systems to verify involvement. The second specific aim will investigate the mechanism of protection of GSTZ1 from inactivation by DCA in the presence of Cl- and certain other anions, and the influence of haplotype. Expressed recombinant GSTZ1A and 1B will be crystallized and the binding sites of DCA and anions studied. The third specific aim will use juvenile and adult rats as models of children and adults to examine the roles of extrahepatic tissues relative to liver in the expression and activity of GSTZ1 following multiple DCA doses, to mimic the clinical use.

项目摘要。 这项研究的广泛，长期目标是了解谷胱甘肽转移酶Z1的特性 （GSTZ1）及其在消除人类研究性药物二氯乙酸（DCA）中的作用 寿命。这很重要，因为虽然DCA是线粒体丙酮酸脱氢酶激酶的抑制剂，但 具有治疗益处作为治疗乳酸性酸中毒，某些实体瘤和肺的代谢调节剂 动脉高血压，在药代动力学中表现出明显的年龄和遗传学与遗传学相关的个人变异性 与DCA的副作用有关。 DCA代谢的第一步是脱氯氧化物， 由GSTZ1催化。 GSTZ1也称为甲基乙酸乙酸酯异构酶，发挥重要的生理作用 在酪氨酸分解代谢途径，甲基乙酸乙酸酯的异构性内源性反应性代谢物中的作用 和甲基丙酮。 GSTZ1主要在肝脏，肾脏，肠，大脑和心脏中表达。这是 唯一已知的酶是将DCA催化为其原代代谢产物乙二醇的脱核化。虽然 众所周知，DCA通过 GSTZ1的灭活，DCA药代动力学显着变异的原因 重复剂量仅部分理解。大多数成年人比重复剂量的DCA更慢。 儿童和清理是依赖儿童和成人的GSTZ1单倍型。有初步证据 DCA代谢的肝外部位相对于DCA之后的肝脏而变得更加重要 治疗，这与年龄有关。最后，氯化物（Cl-）浓度影响 DCA的GSTZ1以单倍型依赖性方式；与细胞质相比，线粒体中的[Cl-]要低得多 被认为是线粒体基质酶更快失活的一个因素，并且可能是 随着细胞内[Cl-]的变化，观察到的年龄依赖性差异的因子因年龄而变化。如何 Cl-保护GSTZ1免受DCA依赖性失活的影响。 该应用程序旨在检查年龄和遗传学的原因 - 与表达和活动相关的变化 人的GSTZ1。提出了三个具体目标。第一个特定目的将研究microRNA的作用 （miR）在调节肝GSTZ1表达中与年龄相关的变化时。这个目标将使用 养育了不同老年供体的人肝脏，以识别miR和基于细胞的系统以验证参与。 第二个具体目的将研究DCA在 Cl-和某些其他阴离子的存在以及单倍型的影响。表示重组GSTZ1A和 1B将结晶，并研究了DCA和阴离子的结合位点。第三个特定目标将使用少年 成年大鼠作为儿童和成人的模型，以检查肝外组织相对于肝脏在 多种DCA剂量后GSTZ1的表达和活性，以模仿临床用途。