Iron in the pathogenesis of Friedreich's ataxia

铁在弗里德赖希共济失调发病机制中的作用

基本信息

批准号：
8655559
负责人：
ARNULF HANS-WERNER KOEPPEN
金额：
$ 26.96万
依托单位：
ALBANY RESEARCH INSTITUTE, INC.
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-05-15 至 2016-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8655559
关键词：
Accounting Aconitate Hydratase Adenine Adverse effects Affect Age Alleles Anabolism Animals Antioxidants Ataxia Atrophic Autolysis Autopsy Axon Binding Biochemical Biogenesis Biological Assay Bismuth Brain Cardiac Myocytes Cardiomyopathies Cause of Death Cells Cerebellum Cessation of life Chelation Therapy Child Citric Acid Cycle Clinical Clinical Trials Complex Cultured Cells Cytoplasmic Granules Data Data Correlations Dentate nucleus Development Diabetes Mellitus Diffuse Disadvantaged Disease Dissociation Effectiveness Electron Microscopy Electron Transport Elements Endocrinologist Energy Metabolism Enzymes Erythrocytes Failure Ferritin Fluorescence Foot Deformities Frequencies Friedreich Ataxia Future Generations Genes Genetic Transcription Genome Globus Pallidus Goals Guanine Health Heart Heart Diseases Homeostasis Human Human Pathology Hyperreflexia Imagery Immunofluorescence Immunologic Immunofluorescence Microscopy Indium Inherited Inherited Spinocerebellar Degenerations Injury Investigation Iron Iron Chelation Isotope Labeling Isotopically-Coded Affinity Tagging Justice Label Lasers Lesion Limb structure Longevity Maps Mass Spectrum Analysis Measures Mediating Metals Methods Mitochondria Mitochondrial Proteins Molecular Morphologic artifacts Mutation Names Natural History Neuraxis Neurologist Neurons Nuclear Optics Orthopedics Oxidative Stress Oxygen Pallor Pathogenesis Patients Peptides Peripheral Peripheral Nervous System Peripheral Nervous System Diseases Persons Pharmaceutical Preparations Phenotype Positioning Attribute Presynaptic Terminals Process Proteins Proteomics RNA Reaction Recovery Reporting Research Research Personnel Resistance Roentgen Rays Role Sampling Sampling Studies Secure Severities Sideroblastic Anemia Site Slide Spastic Spinal Cord Spinal Cord Tract Spinal Ganglia Spinocerebellar Ataxias Staining method Stains Structure Sulfur Surgeon Synapses Techniques Technology Testing Testis Time Tissues Transferrin Receptor Transgenic Model Translations Trinucleotide Repeat Expansion United States Western Blotting Work base cell injury clinical phenotype clinically relevant ferritin receptor frataxin human tissue idebenone illness length inorganic phosphate insight internal control iron metabolism metal transporting protein 1 new technology oxidative damage relating to nervous system response selective expression sensor sensory neuropathy tandem mass spectrometry transmission process young adult

项目摘要

DESCRIPTION (provided by applicant): Friedreich's ataxia (FRDA) is due to homozygous transmission of guanine-adenine-adenine (GAA) trinucleotide repeat expansions in parental frataxin (FXN) genes. The result is deficiency of frataxin. Frataxin is a mitochondrial protein that undergoes specific maturation during and after transfer into the mitochondrial interior. Its putative normal function is the biogenesis of iron- sulfur (Fe-S) clusters conveying iron homeostasis to the entire cell. An inadequate supply of Fe- S clusters seriously impairs the activities of complexes I, II, and III of the mitochondrial electron transport chain, and the citric acid cycle enzyme, aconitase. In addition to suboptimal biosynthesis of high-energy phosphates, lack of frataxin also heightens sensitivity to oxidative stress, presumed to be mediated by free or loosely bound iron. Tissue damage in FRDA is very diverse. In the heart, the disease causes limited accumulation of iron in cardiomyocytes but similar restricted iron excess has not been demonstrated in central or peripheral nervous systems. Assays of total iron do not identify the small catalytic amounts of the metal that are required for the generation of toxic oxygen species. It is also unlikely that human autopsy tissues are suitable for the direct determination of this small pool of highly reactive iron. Nevertheless, failing iron homeostasis can still be assessed by the "downstream" effects of iron on iron-responsive proteins among which ferritin, mitochondrial ferritin, and ferroportin are most likely to undergo changes. In FRDA, the cerebellar dentate nuclei and the dorsal root ganglia (DRG) of the spinal cord are highly vulnerable. This research will test the hypothesis that the adverse effect of frataxin deficiency on these anatomical sites is the result of diffuse or localized iron excess. Regional increase can be determined directly by a new technology, high-definition X-ray fluorescence (HDXRF); and indirectly by a systematic examination of iron-responsive proteins. The investigator will combine HDXRF with slide techniques and biochemical assays of ferritin and ferroportin. HDXRF "maps" iron in tissue blocks and allows its quantification based on standards. Sections of the same block displaying immunocytochemical reaction products of iron-responsive proteins and iron "maps" will be matched precisely to reach a correlation of iron and proteins. Levels of ferritin and ferroportin are expected to be inversely correlated with concentrations of frataxin. A correlation may also exist with the age of the patient at the time of death or the duration of his (her) disease. The expression of mitochondrial ferritin in response to frataxin deficiency is more complex, and results are expected to be all-or-none, as previously reported for FRDA heart. FRDA may also cause iron dysmetabolism due to incorrect intramitochondrial frataxin maturation. This potential contributing factor will be examined by Western blotting of frataxin precursors and the mature functional protein, and in a more robust approach, isotope-coded affinity tag technology and tandem mass spectrometry. This research also utilizes advanced slide technology such as double-label immunofluorescence microscopy to quantify nerve cell damage and loss of synaptic terminals in regions of increased iron; and electron microscopy to reveal cytosolic and mitochondrial ferritin. High normal iron concentration in a given tissue, such as the dentate nucleus, does not necessarily convey increased vulnerability to FRDA. Therefore, the globus pallidus with its equally high iron and ferritin levels will be added as an internal control. Furthermore, the neuropathological phenotype of some spinocerebellar ataxias (SCA) includes lesions of DRG. Samples of SCA will be studied in a parallel effort to determine that the changes in DRG of FRDA patients are specific for inherited frataxin deficiency. The work is clinically relevant because it will resolve questions about iron in the formal pathogenesis and natural history of FRDA, and the potential value of iron chelation.

描述（由申请人提供）：弗里德赖希共济失调（FRDA）是由于亲本frataxin（FXN）基因中鸟嘌呤-腺嘌呤-腺嘌呤（GAA）三核苷酸重复扩增的纯合传递所致。结果是frataxin缺乏。 Frataxin 是一种线粒体蛋白，在转移到线粒体内部期间和之后会经历特定的成熟。其假定的正常功能是铁硫 (Fe-S) 簇的生物发生，将铁稳态传递至整个细胞。 Fe-S 簇供应不足会严重损害线粒体电子传递链复合物 I、II 和 III 以及柠檬酸循环酶、乌头酸酶的活性。除了高能磷酸盐的生物合成不理想之外，frataxin 的缺乏也会增加对氧化应激的敏感性，推测氧化应激是由游离或松散结合的铁介导的。 FRDA 中的组织损伤多种多样。在心脏中，该疾病导致心肌细胞中铁的有限积累，但在中枢或周围神经系统中尚未证明类似的限制性铁过量。总铁的测定无法确定产生有毒氧物质所需的少量催化金属。人体尸检组织也不可能适合直接测定这一小部分高活性铁。然而，铁稳态失败仍然可以通过铁对铁反应蛋白的“下游”影响来评估，其中铁蛋白、线粒体铁蛋白和铁转运蛋白最有可能发生变化。在 FRDA 中，小脑齿状核和脊髓背根神经节 (DRG) 非常脆弱。这项研究将检验以下假设：frataxin 缺乏对这些解剖部位的不利影响是由于弥漫性或局部铁过量造成的。可以通过新技术——高清X射线荧光（HDXRF）直接测定区域的增加；并间接通过铁反应蛋白的系统检查。研究人员将 HDXRF 与载玻片技术以及铁蛋白和铁转运蛋白的生化测定结合起来。 HDXRF“映射”组织块中的铁并允许根据标准对其进行量化。显示铁响应蛋白和铁“图”的免疫细胞化学反应产物的同一块的部分将被精确匹配，以达到铁和蛋白质的相关性。预计铁蛋白和铁转运蛋白的水平与frataxin的浓度呈负相关。患者死亡时的年龄或其疾病持续时间也可能存在相关性。线粒体铁蛋白的表达对 frataxin 缺乏的反应更为复杂，并且结果预计是全有或全无，正如之前针对 FRDA 心脏的报道。 FRDA 还可能由于线粒体内 frataxin 成熟不正确而导致铁代谢障碍。这种潜在的影响因素将通过 frataxin 前体和成熟功能蛋白的蛋白质印迹法以及更可靠的方法、同位素编码亲和标签技术和串联质谱法进行检查。这项研究还利用先进的载玻片技术，例如双标记免疫荧光显微镜，来量化铁含量增加区域的神经细胞损伤和突触末梢损失；和电子显微镜揭示细胞质和线粒体铁蛋白。特定组织（例如齿状核）中正常铁浓度较高，并不一定会增加对 FRDA 的脆弱性。因此，将添加具有同样高铁和铁蛋白水平的苍白球作为内部对照。此外，一些脊髓小脑共济失调 (SCA) 的神经病理表型包括 DRG 病变。我们将同时研究 SCA 样本，以确定 FRDA 患者 DRG 的变化是否是遗传性 frataxin 缺乏症所特有的。这项工作具有临床相关性，因为它将解决有关铁在 FRDA 的正式发病机制和自然史中的问题，以及铁螯合的潜在价值。

项目成果

期刊论文数量（12）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Friedreich ataxia: neuropathology revised.

弗里德赖希共济失调：神经病理学修订。

DOI：
发表时间：
2013-02
期刊：
影响因子：
3.2
作者：
Koeppen, Arnulf H;Mazurkiewicz, Joseph E
通讯作者：
Mazurkiewicz, Joseph E

Friedreich ataxia: metal dysmetabolism in dorsal root ganglia.

Friedreich 共济失调：背根神经节金属代谢异常。

DOI：
发表时间：
2013-06-19
期刊：
影响因子：
7.1
作者：
Koeppen, Arnulf H;Kuntzsch, Erik C;Bjork, Sarah T;Ramirez, R Liane;Mazurkiewicz, Joseph E;Feustel, Paul J
通讯作者：
Feustel, Paul J

Friedreich ataxia: failure of GABA-ergic and glycinergic synaptic transmission in the dentate nucleus.

Friedreich 共济失调：齿状核中 GABA 能和甘氨酸能突触传递失败。

DOI：
发表时间：
2015-02
期刊：
影响因子：
3.2
作者：
Koeppen, Arnulf H;Ramirez, R Liane;Becker, Alyssa B;Feustel, Paul J;Mazurkiewicz, Joseph E
通讯作者：
Mazurkiewicz, Joseph E

The neuropathology of late-onset Friedreich's ataxia.

迟发性弗里德赖希共济失调的神经病理学。

DOI：
发表时间：
2011-03
期刊：
影响因子：
0
作者：
Koeppen, Arnulf H;Morral, Jennifer A;McComb, Rodney D;Feustel, Paul J
通讯作者：
Feustel, Paul J

Central role and mechanisms of β-cell dysfunction and death in friedreich ataxia-associated diabetes.

Friedreich 共济失调相关糖尿病中β细胞功能障碍和死亡的核心作用和机制。

DOI：
发表时间：
2012-12
期刊：
影响因子：
11.2
作者：
Cnop, Miriam;Igoillo;Rai, Myriam;Begu, Audrey;Serroukh, Yasmina;Depondt, Chantal;Musuaya, Anyishai E;Marhfour, Ihsane;Ladrière, Laurence;Moles Lopez, Xavier;Lefkaditis, Dionysios;Moore, Fabrice;Brion, Jean;Cooper, J Mar
通讯作者：
Cooper, J Mar