The role of VEGF in neonatal rat brain after perinatal hypoxic-ischemic damage

描述（由申请人提供）：围产期缺氧缺血（H/l）与儿童脑瘫和其他广泛的神经功能缺陷密切相关。当一些研究人员将注意力集中在使用外源性干细胞进行修复时，我们的实验室正在评估心室下区（SVZ）常驻前体的再生潜力。修复受损器官所需的两个关键过程是增加前体的数量，并引导它们向需要被替换的细胞类型分化。我们最新的初步数据表明：1)尽管H/l损伤后SVZ的大小扩大，但星形胶质细胞和少突胶质细胞的产生发生了变化；2)血管内皮生长因子（VEGF）是缺血后组织修复的关键介质，H/l后快速诱导；3) VEGF增加体外双电位胶质祖细胞的星形胶质细胞的特异性。虽然VEGF已经在成人中风模型中进行了研究，但目前还没有关于围产期脑损伤后VEGF蛋白的研究。我们的假设是，在H/l损伤后，VEGF亚型导致SVZ祖细胞的增殖和分化向星形细胞表型转变，而不是向更合适的少突胶质细胞谱系转变。具体目的1：研究围产期H/l后vegf A、B、C及两种主要受体Flt-1和Flk-1在SVZ的时空表达谱。特异性目的2：研究体外H/l后外源性VEGF-A对svz源性双电位胶质祖细胞增殖分化的影响。所有实验将在大鼠幼鼠身上进行，使用已建立的H/l动物模型。重要的是，这些转化研究调查了临床上重要的人类疾病。该项目将增强我们对新生儿脑损伤后干细胞增殖和分化的认识。这些研究将阐明在围产期脑损伤背景下VEGF在神经祖细胞增殖和分化中的作用。公共卫生相关性：儿童和婴儿脑损伤是一个严重的公共卫生问题，可导致长期的认知、运动和情感障碍。这项研究的目的是更好地了解大脑在H/l后是如何自我修复的。我们的工作也将与中枢神经系统的其他损伤和疾病相关，例如中风和创伤性脑损伤，干细胞治疗将在这些领域得到实施。

DESCRIPTION (provided by applicant): Perinatal hypoxia-ischemia (H/l) is strongly associated with cerebral palsy and a wide spectrum of other neurological deficits in children. While some researchers focus their attention on the use of exogenous stem cells for repair, our lab is evaluating the regenerative potential of the resident precursors of the subventricular zone (SVZ). Two key processes required to repair damaged organs are to amplify the number of precursors and to direct their differentiation towards the cell types that need to be replaced. Our most recent preliminary data indicate: 1) although the SVZ expands in size after H/l injury, there is a shift in the production of astrocytes and oligodendrocytes; 2) vascular endothelial growth factor (VEGF), a key mediator of tissue repair after ischemia, is rapidly induced after H/l; and 3) VEGF increases the specification of astrocytes from bipotential glial progenitors in vitro. While VEGF has been studied in adult stroke models, there are no known studies examining VEGF proteins after perinatal brain damage. Our hypothesis is that VEGF isoforms cause an aberrant shift in the proliferation and differentiation of SVZ progenitors towards astrocytic phenotypes instead of a more appropriate oligodendrocyte lineage after H/l injury. The following specific aims are proposed to test these hypotheses: Specific Aim 1: To characterize the expression profiles spatially and temporally in the SVZ of VEGFs A, B and C and the two main receptors, Flt-1 and Flk-1 after perinatal H/l. Specific Aim 2: To determine the effect of exogenous VEGF-A after in vitro H/l on the proliferation and differentiation of SVZ-derived bipotential glial progenitors. All experiments will be performed on rat pups using an established animal model for H/l. Importantly, these translational studies investigate a clinically important human condition. This project will enhance our understanding of stem cell proliferation and differentiation in the neonatal brain after injury. These studies will elucidate the role of VEGF on neural progenitor cell proliferation and differentiation in the context of perinatal brain injury. PUBLIC HEALTH RELEVANCE: Brain injury in children and infants is a serious public health issue that results in long term cognitive, motor and emotional handicaps. The goal of this research is to better understand how the brain repairs itself after H/l. Our work will also be relevant to other injuries and diseases of the CNS, such as stroke and traumatic brain injury where stem cell therapies will be implemented.