2,3 cAMP in Traumatic Brain Injury

2,3 cAMP 在创伤性脑损伤中的作用

基本信息

批准号：
9100931
负责人：
EDWIN Kerry JACKSON
金额：
$ 33.69万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-07-01 至 2019-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9100931
关键词：
2&apos -adenylic acid Adenosine Age Alkaline Phosphatase Astrocytes Biochemical Biochemistry Brain Brain Injuries Cells Cyclic AMP Cyclic Nucleotides Development Enzymes Evolution Goals Health Human Hypoxia Injury Isomerism Knockout Mice Left Mechanics Mediating Metabolic stress Metabolism Microglia Mitochondria Myelin Myelin Proteins Neurologic Neurons Neuroprotective Agents Neurosciences Neurotoxins Oligodendroglia Outcome P-Glycoproteins Pathway interactions Permeability Play Process Production Public Health Purines Reaction Research Personnel Rodent Second Messenger Systems System Testing Tissues Toxin Traumatic Brain Injury axonal degeneration body system cell type central nervous system injury design extracellular improved outcome in vivo mRNA Transcript Degradation mitochondrial permeability transition pore neurotoxic new therapeutic target novel novel strategies novel therapeutics phosphoric diester hydrolase research study response to injury second messenger tandem mass spectrometry

项目摘要

DESCRIPTION (provided by applicant): The term "cAMP" usually refers to the second messenger 3',5'-cyclic adenosine monophosphate. We serendipitously discovered that organ systems can produce (from mRNA degradation) and export to the extracellular compartment a positional isomer of 3',5'-cAMP, namely 2',3'-cAMP. We showed that organ systems convert extracellular 2',3'-cAMP to 2'-AMP + 3'-AMP and can metabolize 2'-AMP and 3'-AMP to adenosine. We refer to this pathway as the "2',3'-cAMP-adenosine pathway." We also showed that extracellular 2',3'-cAMP increases greatly post-traumatic brain injury (TBI) in brain in rodents and humans; and that when the pathway is impaired, TBI outcomes worsen in rodents. Intracellular 2',3'-cAMP opens mitochondrial permeability transition pores while extracellular adenosine is neuroprotective. Thus the "2',3'- cAMP-adenosine pathway" may be important in TBI because it eliminates an intracellular neurotoxin (export of 2',3'-cAMP) and generates an extracellular neuroprotectant (conversion of 2',3'-cAMP to adenosine). We also identified the enigmatic myelin protein 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) to be the major enzyme that metabolizes extracellular 2',3'-cAMP to 2'-AMP (a key step toward conversion into adenosine). KO mice lacking CNPase produce less extracellular adenosine post-TBI, are more susceptible to injury and develop axonal degeneration with age despite no gross myelin abnormalities. Hypothesis: the "2',3'-cAMP- adenosine pathway" is an endogenous cytoprotective mechanism after TBI. We will elucidate which CNS cell types produce 2',3'-cAMP, what kinds of injury trigger 2',3'-cAMP production, how 2',3'-cAMP is transported out of cells, how downstream AMPs are converted to adenosine, and if manipulating the 2',3'-cAMP-adenosine pathway alters secondary damage. Specific Aim 1: To determine which CNS cell types produce 2',3'-cAMP after injury. Because in vivo TBI increases extracellular 2',3'-cAMP, it is important to determine which CNS cells produce 2',3'-cAMP and whether the effect is injury-type dependent. Aim 1 will determine if metabolic stress, hypoxia or mechanical injury enhances 2',3'-cAMP production by astrocytes, microglia, neurons or oligodendrocytes. Specific Aim 2: To determine whether Multidrug Resistance Protein 4 (MRP4) mediates egress of 2',3'-cAMP. Because 2',3'-cAMP is an intracellular toxin, it is critical to elucidate how 2',3'-cAMP is extrude from CNS cells. Aim 2 will test the hypothesis that MRP4 exports 2',3'-cAMP. Specific Aim 3: To determine if Tissue Alkaline Phosphatase (TAP) participates in the extracellular metabolism of 2'-AMP and 3'- AMP (downstream metabolites of 2',3'-cAMP) to adenosine. Because extracellular adenosine is neuroprotective it is essential to understand how extracellular 2'-AMP and 3'-AMP are converted to extracellular adenosine. Specific Aim 4: To test the hypothesis that the 2',3'-cAMP-adenosine pathway is an endogenous protective mechanism post-TBI. Aim 4 will further test the hypothesis that the 2',3'-cAMP- adenosine pathway is cytoprotective by determining the effect of inhibiting or augmenting it on TBI outcomes.

描述（由申请人提供）：“ cAMP”一词通常是指第二信使3'，5'-循环腺苷单磷酸盐。我们偶然发现，器官系统可以产生（从mRNA降解），并导出到细胞外室一个位置异构体3'，5'-camp，即2'，3'-camp。我们表明，器官系统将细胞外2'，3'-camp转换为2'-Amp + 3'-Amp，可以代谢2'-Amp和3'-Amp将其代谢为腺苷。我们将此途径称为“ 2'，3'-cAMP-腺苷途径”。我们还表明，啮齿动物和人类中大脑的细胞外2'训练会大大增加创伤后脑损伤（TBI）。而且，当路径受损时，啮齿动物的结果会恶化。细胞内2'，3'-训练会打开线粒体渗透性过渡孔，而细胞外腺苷则是神经保护性的。因此，“ 2'，3'-营地 - 腺苷途径”在TBI中可能很重要，因为它消除了细胞内神经毒素（导出2'，3'-cAMP）并产生细胞外神经保护剂（转化2'，2'，3'-camp向腺苷）。我们还鉴定出神秘的髓磷脂蛋白2'，3'-环核苷酸3'-磷酸二酯酶（CNPase）是将细胞外2'，3'-cAMP与2'-amp（向2'-AMP（转化为腺苷转化的关键步骤）的主要酶）。缺乏CNPase的KO小鼠在TBI后产生的细胞外腺苷较少，尽管没有髓磷脂异常，但仍会更容易受到损伤，并随着年龄的增长而发展轴突变性。假设：“ 2'，3'-camp-腺苷途径”是TBI后的一种内源性细胞保护机制。我们将阐明哪种CNS细胞类型产生2'，3'-camp，哪些损伤触发2'，3'-cAMP产生，2'，3'-cAMP如何从细胞中运出细胞，如何将下游AMP转换为腺苷，以及是否操纵2'，3'-camp-tamp-tamp-tamp-tamp adenosine pathway Alters Alters Alters Alters Alters二次损害。特定目标1：确定受伤后哪种CNS细胞类型产生2'，3'-cAMP。由于体内TBI增加了细胞外2'，3'-cAMP，因此必须确定哪些CNS细胞产生2'，3'-cAMP以及效果是否取决于损伤型。 AIM 1将确定代谢应激，缺氧或机械损伤是否可以增强2'，3'-cAMP的产生，由星形胶质细胞，小胶质细胞，神经元或少突胶质细胞产生。特定目的2：确定多药耐药性蛋白4（MRP4）是否介导2'，3'-camp的出口。因为2'，3'-cAMP是一种细胞内毒素，因此阐明2'，3'-cAMP如何从中枢神经系统细胞中挤出至关重要。 AIM 2将检验MRP4出口2'，3'-cAMP的假设。具体目标3：确定组织碱性磷酸酶（TAP）是否参与2'-AMP和3'- AMP的细胞外代谢（2'2'，3'-cAMP的下游代谢产物）到腺苷。由于细胞外腺苷是神经保护性的，因此必须了解细胞外2'-AMP和3'-AMP如何转化为细胞外腺苷。特定目的4：检验2'，3'-cAMP-腺苷途径是TBI后的内源保护机制的假设。 AIM 4将进一步检验以下假设：2'3'-camp-腺苷途径通过确定抑制或增强对TBI结果的影响是细胞保护的。