Reprogramming proinflammatory microglia by restoring mitochondrial function

通过恢复线粒体功能重新编程促炎性小胶质细胞

基本信息

批准号：
10201784
负责人：
BRIAN M POLSTER
金额：
$ 60.34万
依托单位：
UNIVERSITY OF MARYLAND BALTIMORE
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10201784
关键词：
2-oxoglutarate 3-dioxygenase proline Affective Animal Model Antioxidants Attenuated Binding Brain Brain Injuries Cell Fraction Cells Chronic Clinical Cognitive Cognitive deficits Complex Consumption Contusions Data Dementia Drug usage Encephalitis Enzymes Exhibits Female Flow Cytometry Fluorescence Gene Expression Genetic Glycolysis Goals HMGB1 Protein Histopathology Hydroxylation Hypoxia Immune Impairment In Vitro Incubated Individual Inflammatory Injury Interferons Interleukin-1 Interleukin-1 beta Intervention Knock-out Lysosomes Mechanics Metabolic Methods Microglia Mitochondria Modeling Molecular Monitor Motor Mus Nerve Degeneration Neurologic Neurologic Deficit Nitric Oxide Outcome Oxidative Phosphorylation Oxidative Stress Oxygen Oxygen Consumption Pathogenicity Pathway interactions Pharmaceutical Preparations Phenotype Positron-Emission Tomography Process Production Proline Proteins Proteomics Quality Control Reporter Reporting Research Role Severities Signal Transduction Sorting - Cell Movement Source TBI treatment TLR4 gene Testing Traumatic Brain Injury Woman base behavior test brain cell clinically relevant controlled cortical impact cytokine disability effective therapy efficacy evaluation experimental study idebenone in vitro Model in vivo male men mitochondrial dysfunction mouse model neuroprotection novel novel strategies prevent progressive neurodegeneration response response to injury restoration sex translational study

2-oxoglutarate 3-dioxygenase proline Affective Animal Model Antioxidants Attenuated Binding Brain Brain Injuries Cell Fraction Cells Chronic Clinical Cognitive Cognitive deficits Complex Consumption Contusions Data Dementia Drug usage Encephalitis Enzymes Exhibits Female Flow Cytometry Fluorescence Gene Expression Genetic Glycolysis Goals HMGB1 Protein Histopathology Hydroxylation Hypoxia Immune Impairment In Vitro Incubated Individual Inflammatory Injury Interferons Interleukin-1 Interleukin-1 beta Intervention Knock-out Lysosomes Mechanics Metabolic Methods Microglia Mitochondria Modeling Molecular Monitor Motor Mus Nerve Degeneration Neurologic Neurologic Deficit Nitric Oxide Outcome Oxidative Phosphorylation Oxidative Stress Oxygen Oxygen Consumption Pathogenicity Pathway interactions Pharmaceutical Preparations Phenotype Positron-Emission Tomography Process Production Proline Proteins Proteomics Quality Control Reporter Reporting Research Role Severities Signal Transduction Sorting - Cell Movement Source TBI treatment TLR4 gene Testing Traumatic Brain Injury Woman base behavior test brain cell clinically relevant controlled cortical impact cytokine disability effective therapy efficacy evaluation experimental study idebenone in vitro Model in vivo male men mitochondrial dysfunction mouse model neuroprotection novel novel strategies prevent progressive neurodegeneration response response to injury restoration sex translational study

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项目摘要

Traumatic brain injury (TBI) is a major source of long-term disability and dementia. Microglia, long-lived immune cells of the brain, activate to multiple reactive states in response to injury. The extent of pro-inflammatory activation correlates with the severity of neurological impairments, suggesting that unresolved activation is pathogenic. The proposed research is highly significant because it will evaluate a clinically safe intervention to ameliorate harmful TBI-induced microglial activation that may contribute to dementia and other chronic neurological deficits following TBI. Our data suggest that a metabolic shift from oxidative phosphorylation to glycolysis during pro-inflammatory activation involves impairment to the lysosomal turnover of damaged mitochondria by mitophagy, which is followed by Complex I subunit degradation. Idebenone restores oxygen consumption by damaged mitochondria and attenuates pro-inflammatory nitric oxide and interleukin-1beta production. The restoration of oxygen consumption by idebenone decreases intracellular oxygen concentration. We found that simply lowering oxygen concentration by incubating cells under hypoxia prevents Complex I degradation and mitophagy impairment. Unexpectedly, antioxidants failed to yield similar rescue, suggesting a role for oxygen that is independent of oxidative stress. Using proteomics, we discovered a marked accumulation of prolyl 3-hydroxylase 2 (P3H2) in a mitochondria/lysosome-enriched cell fraction. P3H2 gene expression within the brain is microglia-specific, and our preliminary data show elevated P3H2 in mouse peri-contusional cortex after TBI. P3H2 enzyme uses oxygen as a substrate for proline hydroxylation of target proteins. Idebenone may suppress the activity of P3H2 by decreasing oxygen availability, preventing P3H2 from post-translationally modifying mitochondria or lysosome proteins involved in quality control. This study will test the central hypothesis that idebenone suppresses TBI-induced microglial activation, chronic neurodegeneration, and cognitive deficits by reversing P3H2-dependent inhibition of mitophagy. The following specific aims employ state-of-the-art mouse models to monitor microglial mitochondrial turnover and include novel methods to sort and study microglia ex vivo based on mitochondrial function. The experiments in Aim 1 will test the prediction that idebenone rescues mitophagy in pro-inflammatory microglial cells by decreasing intracellular oxygen concentration, thereby inhibiting P3H2 activity. Using both male and female mice and considering sex as a variable, the experiments in Aim 2 will test the prediction that idebenone or genetic P3H2 knockout ameliorates TBI-induced pro-inflammatory microglia accumulation and neurological deficits by rescuing microglial mitophagy. Positive outcomes will support translational studies of idebenone to treat TBI-induced dementia, with the potential to help millions of men and women living with the devastating consequences of TBI.

创伤性脑损伤（TBI）是长期残疾和痴呆的主要来源。小胶质细胞，长寿大脑的免疫细胞会因损伤而激活多个反应性态。促炎的程度激活与神经系统障碍的严重程度相关，表明未解决的激活是致病性。拟议的研究非常重要，因为它将评估临床安全的干预措施改善有害的TBI诱导的小胶质细胞激活，可能有助于痴呆和其他慢性 TBI之后的神经缺陷。我们的数据表明，代谢从氧化磷酸化转变为促炎性激活期间的糖酵解涉及受损的溶酶体周转率线粒体通过线粒体，随后是复杂的I亚基降解。伊德替酮恢复氧气线粒体损坏的消费量并减弱促炎性一氧化氮和白介素1Beta 生产。通过易氧消耗的易氧降低会降低细胞内氧浓度。我们发现，仅通过在缺氧下孵育细胞来降低氧气浓度可以防止复合物I 降解和线粒体障碍。出乎意料的是，抗氧化剂未能产生类似的营救，这表明氧的作用，独立于氧化应激。使用蛋白质组学，我们发现了一个明显的积累线粒体/溶酶体富集的细胞馏分中的三羟基丙酰酶2（P3H2）的含量。 P3H2基因表达大脑是小胶质细胞特异性的，我们的初步数据显示，小鼠围围皮层中的P3H2升高在TBI之后。 P3H2酶使用氧作为靶蛋白脯氨酸羟基化的底物。 iDebenone可能通过降低氧气的可用性来抑制P3H2的活性，从而防止P3H2在跨化后进行p3H2 修饰参与质量控制的线粒体或溶酶体蛋白。这项研究将测试中央伊德酮抑制了TBI诱导的小胶质细胞激活，慢性神经变性和通过逆转P3H2依赖性抑制线粒体的认知缺陷。以下特定目的采用最先进的鼠标模型来监视小胶质细胞方面的转换，并包括分类和分类的新方法基于线粒体功能研究小胶质细胞。 AIM 1中的实验将测试以下预测伊德贝诺酮通过减少细胞内氧气来挽救促炎小胶质细胞的线粒体浓度，从而抑制P3H2活性。同时使用雄性和雌性小鼠并将性视为变量，AIM 2中的实验将测试iDebenone或遗传p3H2敲除改善的预测 TBI诱导的促炎性小胶质细胞积累和神经系统缺陷，通过营救小胶质细胞噬菌体。积极的结果将支持iDebenone的转化研究，以治疗TBI诱导的痴呆，并与帮助数百万男女承受TBI毁灭性后果的潜力。