NEUROPROTECTIVE GROWTH FACTORS IN TRAUMATIC BRAIN INJURY

描述：(逐字摘自申请人摘要)机制(S) 颅脑损伤后迟发性继发性损伤可能涉及 涉及有丝分裂原的特定细胞内信号通路的变化 活化蛋白(MAP)激酶JNK和ERK1/2，以及长期基因组 改变。这些致病分子事件提供了治疗的靶点 旨在预防或限制神经功能障碍的生长因子。这个 调查人员和其他人已经产生了初步数据，表明 急性(伤后24小时)注射外源性NGF或碱性成纤维细胞 生长因子对实验性脑损伤的神经保护作用 受伤。具体目标1将评估NGF或bFGF的应用 在急性创伤后时期(从受伤后24小时开始)将减弱 长期神经功能障碍和神经变性(凋亡/坏死性)细胞 大鼠实验性侧向液压冲击(FP)脑损伤后的损失。 研究人员将有选择地将这些生长因子直接注入 损伤后2周的脑损伤情况，并进行行为评估 动物在慢性损伤后3个月内进行神经运动和 感觉运动功能障碍、认知缺陷和局部细胞死亡。特定的 目标2将评估特定地图中的时间和区域变化 实验性FP脑损伤后KK(JNK/Erk 1/2)信号通路 并将神经生长因子或碱性成纤维细胞生长因子治疗的神经保护作用与 逆转创伤后JNK/ERK的病理变化。他们将使用 Western blotting和免疫组织化学支持他们的试验数据，即脑外伤 导致促死亡激酶JNK信号通路的激活和a 伴随而来的是通过促进生存的Erk1/2途径的信号减少。这个 神经生长因子或碱性成纤维细胞生长因子治疗的效果及停止治疗2周(即生长 因子戒断)对这些创伤诱导的信号转导级联的影响 然后在区域和时间上进行评估。在具体目标3中，他们将 量化神经生长因子或碱性成纤维细胞生长因子治疗对创伤所致脑血管改变的影响 细胞死亡/存活和长期生存相关基因的表达谱 受损中枢神经系统的可塑性/重塑。调查人员将使用激光 捕获显微解剖和反向Northern杂交技术 定制设计的槽印，用于量化选定的面板的表达水平 基因，包括细胞死亡/存活基因，细胞骨架基因，生长相关基因 蛋白质和细胞因子。基因组变化将在翻译会议上得到确认 与选定蛋白质的免疫组织化学水平。在具体目标4中， 研究人员将有选择地向受伤的大脑中注入NGF或bFGF 从受伤后2周或1个月开始的2周治疗期和评估 这些延迟治疗范例改善长期疗效的能力 神经运动和认知功能(受伤后最多3个月)和 减轻创伤后细胞的渐进性死亡。

DESCRIPTION: (Verbatim from the Applicant's Abstract) The mechanism(s) of delayed secondary injury following traumatic brain injury (TBI) may involve the alteration of specific intracellular signaling pathways involving the mitogen activated protein (MAP) kinases JNK and Erk 1/2, as well as long-term genomic changes. These pathogenic molecular events provide targets for treatment with growth factors intended to prevent or limit neurologic disability. The investigators, among others, have generated preliminary data suggesting that acute (24 hr postinjury) administration of exogenous NGF or basic fibroblast growth factor (bFGF) may be neuroprotective in experimental models of brain injury. Specific Aim 1 will assess whether administration of either NGF or bFGF in the acute post-traumatic period (beginning 24 hr postinjury) will attenuate long-term neurologic disability and neurodegenerative (apoptotic/necrotic) cell loss following experimental lateral fluid percussion (FP) brain injury in rats. The investigators will selectively infuse these growth factors directly into the injured brain over a 2-week postinjury period, and behaviorally evaluate the animals over a chronic 3-month postinjury period for neurologic motor and sensorimotor dysfunction, cognitive deficits, and regional cell death. Specific Aim 2 will evaluate the temporal and regional alterations in specific MAP kinase (JNK/Erk 1/2) signaling pathways following experimental FP brain injury, and relate the neuroprotective effects of therapy with NGF or bFGF to a reversal of the pathologic changes in JNK/Erk induced by trauma. They will use Western blotting and immunohistochemistry to support their pilot data that TBI results in activation of the pro-death kinase JNK signaling pathway and a concomitant decrease in signaling through the pro-survival Erk 1/2 pathway. The effects of NGF or bFGF therapy and cessation of 2-week therapy (i.e., growth factor withdrawal) on these trauma-induced signal transduction cascades will then be regionally and temporally evaluated. In Specific Aim 3, they will quantify the effects of NGF or bFGF therapy on trauma-induced alterations in expression profiles of genes involved in cell death/survival and long-term plasticity/remodeling of the injured CNS. The investigators will use laser capture microdissection and reverse-Northern hybridization techniques with custom-designed slot-blots to quantify expression levels of a selected panel of genes, including cell death/survival genes, cytoskeletal genes, growth-related proteins, and cytokines. Genomic changes will be confirmed at a translational level with immunohistochemistry for selected proteins. In Specific Aim 4, the investigators will selectively infuse NGF or bFGF into the injured brain over a 2-week treatment period beginning 2 weeks or 1 month postinjury and evaluate the ability of these delayed treatment paradigms to improve long-term neurological motor and cognitive function (up to 3 months postinjury) and attenuate progressive post-traumatic cell death.