Astroglial Cells in Perinatal Brain Injury

围产期脑损伤中的星形胶质细胞

• 批准号: 8092550
• 负责人: FLORA M VACCARINO
• 金额: $ 35.48万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8092550
• 关键词: Action Potentials; Address; Adolescent; Affect; Alleles; Animals; Anoxic Encephalopathy; Area; Astrocytes; Birth; Brain; Brain Injuries; Brain region; Candidate Disease Gene; Cell Lineage; Cells; Cerebral cortex; Cerebrum; Child; Childhood; Chronic; Cognitive; Development; Electroporation; Embryonic Development; Environment; FGFR1 gene; Fibroblast Growth Factor Receptor 1; Gene Expression Profile; Genes; Genetic Recombination; Glial Fibrillary Acidic Protein; Growth Factor; Health; Hypoxia; Infection; Injury; Lead; Left; Lentivirus Vector; Location; Modeling; Molecular; Mus; Neuroglia; Neurons; Oligodendroglia; Oxygen; Patients; Perinatal; Perinatal Brain Injury; Perinatal Hypoxia; Pharmaceutical Preparations; Premature Birth; Proliferating; Property; Proteins; Psyche structure; Radial; Recovery; Reporter; Reporter Genes; Research; Role; Source; Subfamily lentivirinae; Synapses; Tamoxifen; Testing; Therapeutic Uses; Time; Transgenic Mice; Transplantation; Up-Regulation; brain repair; brain volume; cell type; cerebral atrophy; clinically relevant; disability; excitatory neuron; gray matter; immunocytochemistry; improved; in vivo; inhibitory neuron; injured; member; migration; mouse model; nerve stem cell; novel therapeutic intervention; olfactory bulb; postnatal; precursor cell; progenitor; promoter; recombinase; regenerative; repaired; research study; response; subventricular zone

DESCRIPTION (provided by applicant): Astroglial neural stem cells (NSC) expressing GFAP and Sox2 proliferate in germinal areas such as the subventricular zone (SVZ) in the recovery period following hypoxic injury. While we know a great deal about how GFAP+ NSC generate neurons for the olfactory bulb in the normal developing brain, we are still far from understanding whether and how these precursors contribute to brain repair after injury. In the first specific aim, we address this clinically relevant issue by asking whether reactive GFAP+ NSC give rise to new cortical neurons and oligodendrocytes in the cerebral cortex of juvenile mice that survive chronic sublethal hypoxia, a model for premature birth. We will investigate what types of neurons arise from these cells in normal and hypoxic conditions and whether these neurons are electrophysiologically active and normally integrated in the cortical circuitry. This will be accomplished by genetically marking astroglial lineage cells with EGFP and gal reporter genes, using a transgenic mouse carrying a drug-inducible Cre recombinase gene expressed under the GFAP promoter. In the second specific aim, we will investigate whether the GFAP+ cells that give rise to cortical neurons are located in the SVZ and give rise to precursors that subsequently migrate to the cerebral cortex, or whether they are located within the cortex. For this, we will microinject a lentiviral vector transducing Cre under the GFAP promoter to permanently mark cortical or SVZ GFAP+ cells with heritable gal expression. To understand whether hypoxic rearing changes the intrinsic potential of GFAP+ NSC or affects their environment, we will FACS-purify GFAP+cells from the SVZ of normoxic or hypoxic mice and follow their fate after transplantation in the brain of normoxic or hypoxic recipients. The Fibroblast Growth Factor Receptor 1 (Fgfr1) gene product is upregulated by hypoxia in GFAP+ NSC of the SVZ and appears to be important for recovery. In specific aim 3, we will delete the Fgfr1 gene within GFAP+ cells using inducible Cre recombination in vivo. This will test whether Fgfr1 is required before or after the hypoxic insult within GFAP+ cells to promote their proliferation and differentiation in the immature hypoxic brain. Our results may lead to novel therapeutic approaches involving exogenous or endogenous astroglial precursors aimed at improving recovery in pediatric patients suffering from hypoxic encephalopathy. PUBLIC HEALTH RELEVANCE: Hypoxia low oxygen is a frequent cause of brain injury in premature birth and other birth-related complications. Hypoxia often results in smaller brain volume and mental disability; however a portion of the affected children undergoes a remarkable improvement in both cerebral cortical gray matter volume and cognitive scores. Using a mouse model of chronic sublethal hypoxia that reproduces both the initial brain atrophy and the subsequent recovery, we will investigate the cellular and molecular mechanisms underlying recovery. We will focus on specific growth factor that affect the degree to which neural stem cells naturally present in the brain generate neurons and glia that survive long-term in the injured brain.

描述（由申请人提供）：在低氧损伤后的恢复期内，在生发区域（例如脑室下区（SVZ））在生发区域中表达GFAP和SOX2的星形胶质神经干细胞（NSC）。尽管我们对GFAP+ NSC如何在正常发育发育的大脑中为嗅球生成神经元有很多了解，但我们仍然远没有理解这些前体在受伤后是否有助于这些前体有助于大脑修复。在第一个具体目的中，我们通过询问反应性GFAP+ NSC是否会引起新的皮质神经元和少突胶质细胞的新皮层和少突胶质细胞的少年小鼠的新皮质神经元和少突胶质细胞，从而解决了慢性余生性缺氧，这是一种早产模型。我们将研究在正常和低氧条件下这些细胞产生的神经元类型，以及这些神经元是否具有电生理学活性并正常整合在皮质回路中。这将通过使用EGFP和GAL报告基因遗传标记星形胶质细胞，该基因使用携带在GFAP启动子下表达的药物诱导的CRE重组酶基因的转基因小鼠。在第二个特定目的中，我们将研究产生皮质神经元的GFAP+细胞是否位于SVZ中，并产生随后迁移到大脑皮层的前体，还是它们位于皮质内。为此，我们将在GFAP启动子下方的慢病毒载体转导CRE以具有可遗传的GAL表达的永久标记皮质或SVZ GFAP+细胞。为了了解低氧饲养是会改变GFAP+ NSC的内在潜力还是影响其环境，我们将从常氧或低氧小鼠的SVZ中固定GFAP+细胞，并在正常氧化或低氧受体移植后跟随其命运。成纤维细胞生长因子受体1（FGFR1）基因产物在SVZ的GFAP+ NSC中的缺氧上调，对于恢复似乎很重要。在特定的目标3中，我们将使用诱导的CRE重组在体内删除GFAP+细胞中的FGFR1基因。这将测试在GFAP+细胞内缺氧损伤之前或之后是否需要FGFR1，以促进其在未成熟的低氧大脑中的增殖和分化。我们的结果可能导致新型的治疗方法，涉及旨在改善缺氧性脑病患小儿恢复的外源或内源性星形胶质细胞前体。公共卫生相关性：低氧低氧是过早出生和其他与出生有关的并发症的常见原因。缺氧通常会导致大脑体积和精神残疾较小。然而，一部分受影响的儿童在脑皮质灰质体积和认知评分方面都有显着改善。利用慢性超氧缺氧的小鼠模型，该模型既可以再现了初始脑萎缩和随后的恢复，我们将研究恢复恢复的细胞和分子机制。我们将重点关注特定的生长因子，这些因子影响神经干细胞在大脑中自然存在的神经干细胞在受伤大脑中长期存活的神经元和神经胶质的程度。