Mechanisms of Hemoglobin Adaptation to Hypoxia in High-altitude Rodents

高海拔啮齿动物血红蛋白适应缺氧的机制

基本信息

批准号：
7842973
负责人：
Jay Storz
金额：
$ 22.08万
依托单位：
UNIVERSITY OF NEBRASKA LINCOLN
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-01 至 2011-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7842973
关键词：
Adopted Adult Aerobic Affect Affinity Alleles Altitude American Amino Acids Animals Binding Binding Sites Biochemical Biochemistry Biological Assay Blood Blood Substitutes Bohr effect California Cell Respiration Cells Characteristics Chloride Ion Chronic Complex Computer Analysis Computer Simulation DNA Sequence Deer Mouse Disease Management Embryo Environment Equilibrium Erythrocytes Exhibits Genes Genetic Genetic Polymorphism Genotype Globin Goals Hemeproteins Hemoglobin Human Hypoxia In Vitro Individual Interdisciplinary Study Ligand Binding Ligands Mammals Measurement Measures Messenger RNA Metabolism Minor Modeling Modification Molecular Molecular Analysis Molecular Evolution Mus Mutation Natural Selections Nevada Nitric Oxide North America Nucleotides Oxygen Pattern Peromyscus Pharmaceutical Preparations Phosphoric Acid Esters Physiological Adaptation Population Population Genetics Process Property Protein Biochemistry Protein Isoforms Proteins Protons Reactive Oxygen Species Relative (related person)Research Research Project Grants Rodent Role Sampling Sea Stress Structure Surveys System Temperature Testing Therapeutic Tissues Transcript Transcriptional Regulation Variant base candidate identification design diphosphoglycerate duplicate genes experimental analysis gene therapy genetic analysis human disease insight molecular site novel oxygen transport protein structure function research study stoichiometry structural biology systems research theories tool

项目摘要

The purpose of the proposed research project is to elucidate the molecular basis of physiological adaptation to high-altitude hypoxia, a condition resulting from a reduced supply of oxygen to the cells of respiring tissues. Specifically, the proposed research will involve a structural and functional analysis of hemoglobin variation that is associated with adaptive variation in the blood biochemistry and aerobic metabolism of high-altitude deer mice (Peromyscus maniculatus). Insights into the molecular mechanisms that allow high-altitude animals to survive and function under conditions of chronic hypoxia can aid our understanding and management of disease processes in humans that compromise the oxygen transport system. By identifying the molecular underpinnings of hypoxia tolerance, it may be possible to replicate the mechanism with novel drug-based therapy, gene therapy, and hemoglobin-based blood substitutes. This highly interdisciplinary study will integrate the tools and theory of molecular population genetics, molecular evolution, structural biology, and protein biochemistry. The specific aims of this research project are (1) To identify the specific amino acid mutations that are responsible for hemoglobin adaptation to hypoxia; (2) To assess whether modifications of hemoglobin structure are also associated with regulatory adjustments in the composition stoichiometry of different hemoglobin isoforms in circulating red blood cells; and (3) To assess the functional consequences of the observed structural and regulatory changes. After first conducting a population-level survey of DNA sequence variation to identify naturally occurring mutations in the globin genes of high-altitude deer mice, this study will involve a population-genetic analysis to infer which of the observed amino-acid changes may be attributable to positive Darwinian selection, an analysis of regulatory variation at the mRNA and protein levels, an 'in silico' computational analysis to predict effects on hemoglobin-oxygen affinity, and an 'in vitro' experimental analysis to assess how the identified structural and regulatory changes influence intrinsic oxygen affinity, as well as sensitivities to temperature, protons (Bohr effect), allosteric effectors, and metabolism of reactive oxygen species and nitric oxide. By identifying mechanisms of hemoglobin adaptation that have evolved in natural populations of high-altitude rodents, the proposed research project should provide novel insights into the molecular basis of hypoxia tolerance. Narrative The goal of the proposed research project is to identify the specific changes in hemoglobin function that have evolved in mice that are native to high-altitude environments. By identifying the specific molecular mechanisms that have enabled high-altitude animals to survive and function under low oxygen conditions, it may be possible to replicate the mechanism in therapeutic treatments of human diseases that compromise the oxygen transport system.

拟议研究项目的目的是阐明其分子基础对高原缺氧的生理适应，这是由于高原缺氧减少而导致的一种状况向呼吸组织的细胞供应氧气。具体来说，拟议的研究将涉及相关血红蛋白变异的结构和功能分析血液生化和高海拔有氧代谢的适应性变化鹿鼠（Peromyscus maniculatus）。深入了解分子机制让高海拔动物在慢性缺氧的条件下生存并发挥功能可以帮助我们理解和管理人类疾病过程损害氧气运输系统。通过识别分子基础缺氧耐受性，有可能用新型药物复制该机制疗法、基因疗法和基于血红蛋白的血液替代品。这高度跨学科研究将整合分子群体的工具和理论遗传学、分子进化、结构生物学和蛋白质生物化学。具体的该研究项目的目标是 (1) 确定特定的氨基酸突变负责血红蛋白适应缺氧； (2) 评估是否血红蛋白结构的改变也与调节调节有关循环红血中不同血红蛋白亚型的组成化学计量细胞； (3) 评估观察到的结构和功能的功能后果监管变化。首次对 DNA 序列进行人群水平调查后变异以识别高海拔珠蛋白基因中自然发生的突变鹿小鼠，这项研究将涉及群体遗传分析，以推断哪些观察到的氨基酸变化可能归因于积极的达尔文选择， mRNA 和蛋白质水平的调控变异分析，“计算机模拟” 计算分析预测对血红蛋白-氧亲和力的影响，以及“体外” 实验分析以评估已确定的结构和监管变化如何影响内在氧亲和力以及对温度、质子的敏感性（玻尔效应）、变构效应以及活性氧和一氧化氮的代谢。通过识别自然进化的血红蛋白适应机制高海拔啮齿动物种群，拟议的研究项目应提供新颖的深入了解耐缺氧的分子基础。叙述拟议研究项目的目标是确定以下方面的具体变化：原产于高海拔地区的小鼠体内进化出的血红蛋白功能环境。通过识别特定的分子机制使高海拔动物能够在低氧条件下生存和发挥作用在条件允许的情况下，有可能在治疗中复制该机制治疗损害氧气运输系统的人类疾病。