Hematopoietic Growth Factors and Chronic Stroke

造血生长因子与慢性中风

• 批准号: 8653118
• 负责人: LI-RU ZHAO
• 金额: $ 15.19万
• 依托单位: UPSTATE MEDICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8653118
• 关键词: Hematopoietic; Growth; Factors; Chronic; Stroke

DESCRIPTION (provided by applicant): Stroke, a neurological disorder with a high incidence in the elderly, is a leading cause of long-term disability in adults worldwide. Stroke is also an enormous public health problem and a serious public financial burden in the United States. Chronic stroke is identified as the period beyond 3-6 months after stroke onset. Currently, no pharmaceutical treatment is available for chronic stroke victims. Stem cell factor (SCF) and granulocyte- colony stimulating factor (G-CSF) are hematopoietic growth factors (HGFs) that regulate blood cell production and mobilize bone marrow stem cells (BMSCs) into the blood. Our recent publications have shown that the receptors for SCF and G-CSF are expressed by neurons, that both SCF and G-CSF can pass through the blood-brain barrier, and, more importantly, that SCF in combination with G-CSF (SCFCSF) shows therapeutic benefits for chronic stroke in a rat model of stroke. However, it remains entirely unknown how SCFCSF repairs a permanently damaged brain during chronic stroke. The objective of this project is to address this unanswered question. Supported by considerable preliminary data, the central hypothesis is that neuronal network remodeling contributes to SCFCSF-induced functional recovery in chronic stroke and that the neuronal network remodeling is accomplished by the direct effects of SCFCSF on neurons and the indirect effects via BMSCs. Using neuronal and BMSC cultures together with stroke models in aged spontaneously hypertensive rats and in aged wild type or transgenic C57 BL mice expressing yellow or cyan fluorescent proteins only in neurons (Thy-1-YFP, Thy-1-CFP), and bone marrow transplantation to track BMSCs, this hypothesis will be tested by pursuing two specific aims. Aim #1 is to determine whether SCF CSF-induced functional benefits in chronic stroke are dependent upon MEK/ERK and PI3k/Akt pathway- mediated neuronal network remodeling. Western blots, cell signaling blockade, RNA interference, 2-photon live imaging and neurological deficit examinations will be used. Aim #2 is to identify the role of the S100A8/A9 chemical gradient established by SCFCSF in homing BMSCs to the brain and to determine the contribution of the BMSCs to SCFCSF-induced functional recovery from chronic stroke. BMSC migration assays, S100A8/A9 gene silencing by RNA interference, and sensorimotor functional evaluation will be utilized. The proposed research is significant because it will advance and extend understanding of how HGFs repair the brain after permanent damage by stroke. Additionally, it will significantly contribute to the development of a unique therapeutic strategy for treatment of chronic stroke. This contribution is in keeping with the NIH mission to reduce national and personal burdens caused by illness and disability. PUBLIC HEALTH RELEVANCE: The proposed study focuses on a highly important, but under-investigated topic: a new therapeutic strategy to treat chronic stroke in the aged population. This research is directly relevant to public health. The findings can provide fresh insights into the contribution of hematopoietic growth factors in brain repair. Additionally, this knowledge may also lead to the development of new treatments for other neurological disorders and neurodegenerative diseases.

描述（由申请人提供）：中风是一种老年人发病率高的神经系统疾病，是全球成年人长期残疾的主要原因。在美国，中风也是一个巨大的公共卫生问题和严重的公共财政负担。慢性脑卒中是指脑卒中发作后3-6个月以上的一段时间。目前，没有药物治疗可用于慢性中风患者。干细胞因子（SCF）和粒细胞集落刺激因子（G-CSF）是造血生长因子（HGF），其调节血细胞产生并动员骨髓干细胞（BMSC）进入血液。我们最近的出版物表明，SCF和G-CSF的受体由神经元表达，SCF和G-CSF都可以通过血脑屏障，更重要的是，SCF与G-CSF（SCFCSF）的组合显示出对大鼠中风模型中慢性中风的治疗益处。然而，目前尚不清楚SCFCSF如何修复慢性中风期间永久受损的大脑。这个项目的目的就是解决这个悬而未决的问题。大量的初步数据支持的中心假设是，神经元网络重塑有助于SCFCSF诱导的功能恢复在慢性中风，神经元网络重塑是通过SCFCSF对神经元的直接作用和通过BMSC的间接作用来完成的。使用神经元和BMSC培养物以及老年自发性高血压大鼠和仅在神经元中表达黄色或青色荧光蛋白的老年野生型或转基因C57 BL小鼠（Thy-1-YFP，Thy-1-CFP）中的中风模型，以及骨髓移植来追踪BMSC，将通过追求两个特定目标来测试该假设。目的#1是确定SCF CSF诱导的慢性中风中的功能益处是否依赖于MEK/ERK和PI 3 k/Akt通路介导的神经元网络重塑。将使用蛋白质印迹、细胞信号传导阻断、RNA干扰、双光子活体成像和神经功能缺损检查。目的#2是确定由SCFCSF建立的S100 A8/A9化学梯度在将BMSC归巢到脑中的作用，并确定BMSC对SCFCSF诱导的慢性中风功能恢复的贡献。将使用BMSC迁移试验、通过RNA干扰的S100 A8/A9基因沉默和感觉运动功能评价。这项研究意义重大，因为它将促进和扩展对HGFs如何在中风造成永久性损伤后修复大脑的理解。此外，它将大大有助于发展一种独特的治疗策略，治疗慢性中风。这一贡献符合国家卫生研究院的使命，即减少疾病和残疾造成的国家和个人负担。 公共卫生相关性：这项拟议的研究集中在一个非常重要但研究不足的主题：治疗老年人群慢性卒中的新治疗策略。这项研究与公共卫生直接相关。这些发现可以为造血生长因子在脑修复中的贡献提供新的见解。此外，这些知识也可能导致其他神经系统疾病和神经退行性疾病的新治疗方法的开发。