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：
7904133
负责人：
Jay Storz
金额：
$ 26.24万
依托单位：
UNIVERSITY OF NEBRASKA LINCOLN
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-09-22 至 2013-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7904133
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 public health relevance research study stoichiometry structural biology theories tool

项目摘要

DESCRIPTION (provided by applicant): 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. PUBLIC HEALTH RELEVANCE: 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.

描述（由申请人提供）：拟议研究项目的目的是阐明高海拔缺氧生理适应的分子基础，高海拔缺氧是由于呼吸组织细胞供氧减少而导致的状况。具体来说，拟议的研究将涉及血红蛋白变异的结构和功能分析，该变异与高海拔鹿鼠（Peromyscus maniculatus）血液生化和有氧代谢的适应性变异相关。深入了解高海拔动物在慢性缺氧条件下生存和发挥功能的分子机制，可以帮助我们了解和管理人类损害氧气运输系统的疾病过程。通过确定耐缺氧的分子基础，有可能通过新型药物疗法、基因疗法和基于血红蛋白的血液替代品来复制该机制。这项高度跨学科的研究将整合分子群体遗传学、分子进化、结构生物学和蛋白质生物化学的工具和理论。该研究项目的具体目标是（1）确定导致血红蛋白适应缺氧的特定氨基酸突变； (2) 评估血红蛋白结构的改变是否也与循环红细胞中不同血红蛋白亚型的组成化学计量的调节调整有关； (3) 评估观察到的结构和监管变化的功能后果。在首先对 DNA 序列变异进行群体水平调查以识别高海拔鹿小鼠球蛋白基因中自然发生的突变之后，这项研究将涉及群体遗传分析，以推断观察到的氨基酸变化中的哪些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、预测对血红蛋白-氧亲和力影响的“计算机”计算分析以及评估已识别的结构和调控效果的“体外”实验分析变化影响内在氧亲和力，以及对温度、质子（玻尔效应）、变构效应器以及活性氧和一氧化氮的代谢的敏感性。通过确定高海拔啮齿动物自然种群中进化的血红蛋白适应机制，拟议的研究项目应该为耐缺氧的分子基础提供新的见解。公共健康相关性：拟议研究项目的目标是确定高海拔环境下的小鼠血红蛋白功能的具体变化。通过确定使高海拔动物能够在低氧条件下生存和发挥作用的特定分子机制，有可能在治疗损害氧运输系统的人类疾病中复制该机制。