Genetically modified fibroblast grafts into spinal cord

转基因成纤维细胞移植到脊髓

• 批准号: 6470106
• 负责人: ALAN R. TESSLER
• 金额: $ 17.76万
• 依托单位: MCP HAHNEMANN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-04-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6470106
• 关键词: axon; central neural pathway /tract; chordate locomotion; denervation; embryo /fetus tissue transplantation; fibroblasts; gene therapy; laboratory rat; motor neurons; nervous system regeneration; nervous system transplantation; neuromuscular function; neurotrophic factors; newborn animals; spinal cord injury; spinal cord surgery; spinal reflex; vestibular pathway

DESCRIPTION (provided by applicant) Our previous studies have shown that fibroblasts genetically modified to express Brain Derived Neurotrophic Factor (BDNF) promote long distance regeneration of rubrospinal axons and partial recovery of motor function when transplanted into a subtotal hemisection spinal cord injury in adult rats. The proposed experiments will test the idea that additional populations of supraspinal neurons important for locomotion will regenerate in response to transplants of fibroblasts engineered to express BDNF and neurotrophin-3 (NT3). Our aim is to demonstrate that these transplants will be effective not only when provided at the time of injury but also after a delay and can therefore be applied to models of chronic spinal cord injury. The first set of experiments will test the hypothesis that fibroblasts genetically modified to express BDNF or NT3 or a combination of these fibroblasts will elicit regeneration of corticospinal, vestibulospinal, and rubrospinal axons when transplanted acutely into a cervical hemisection. Anterograde and retrograde tracing techniques will provide a quantitative and qualitative characterization of the regeneration, including the numbers of neurons that regenerate, their path, length and targets. Immunocytochemical methods will identify host dorsal roots that grow into the transplants and serotonergic and noradrenergic axons originating in the brainstem that grow into the transplants and caudal host spinal cord. The second set of experiments will test the idea that engineered fibroblasts that promote the greatest amount of regeneration in rats with acute hemisections, presumably a combination of BDNF- and NT3-expressing fibroblasts, will also elicit regeneration of supraspinal axons when transplanted into a hemisection after delays as long as 12 weeks (chronic injury). We will maximize the survival of axotomized neurons by introducing the antiapoptotic Bcl-2 gene by injection of plasmid both at the time of the initial injury and at the time of transplantation. Retrograde and anterograde tracing studies and immunocytochemical methods will permit analysis of the regeneration. The third set of experiments will examine the effects of these transplants in acute and chronic spinal cord transections. Transection is the most challenging but also the least ambiguous experimental spinal cord injury, and regeneration in this model will represent compelling confirmation of the effectiveness of these transplants. A battery of tests will evaluate motor and sensory function in each series of experiments, and re-lesion rostral to the initial injury will indicate whether regenerated axons contribute to recovery. Physiological assessment of the recovered functions will be studied as a component of two Projects. The success of these strategies will be an important step toward developing an effective treatment in humans.

描述（由申请人提供） 我们以前的研究表明，成纤维细胞基因修饰， 表达脑源性神经营养因子（BDNF）促进长距离 当红核脊髓轴突再生和运动功能部分恢复时 移植到成年大鼠的脊髓半切损伤中。的 拟议的实验将测试的想法，额外的人口， 对运动很重要的脊髓上神经元会再生， 移植的成纤维细胞工程表达BDNF和神经营养素-3（NT 3）。 我们的目标是证明这些移植不仅有效， 在受伤时提供，但也在延迟后提供，因此可以 应用于慢性脊髓损伤模型。第一组实验 将检验通过基因修饰表达BDNF的成纤维细胞 或NT 3或这些成纤维细胞的组合将引发再生， 急性移植时皮质脊髓、前庭脊髓和红核脊髓轴突 变成宫颈半切术。顺行和逆行追踪技术将 提供再生的定量和定性表征， 包括再生神经元的数量，它们的路径，长度， 目标的免疫细胞化学方法将确定宿主的背根生长 移植物和肾上腺素能和去甲肾上腺素能轴突起源于 长入移植物的脑干和尾部宿主脊髓。的 第二组实验将测试工程化成纤维细胞的想法， 促进急性半脑切除大鼠的最大再生量， 推测BDNF和NT3表达的成纤维细胞的组合，也将 当移植到半切处时引起脊髓上轴突再生 延迟长达12周（慢性损伤）。我们将最大限度地 通过引入抗凋亡Bcl-2基因， 在初始损伤时和在随后的损伤时均注射质粒。 移植逆行和顺行追踪研究， 免疫细胞化学方法将允许分析再生。第三 一组实验将检查这些移植在急性和 慢性脊髓横断横切是最具挑战性的， 最不含糊的实验性脊髓损伤和再生， 模型将代表这些有效性的令人信服的确认 移植一系列测试将评估运动和感觉功能， 每一系列的实验，以及在最初损伤的喙部的再损伤将 表明再生轴突是否有助于恢复。生理 评估恢复的功能将作为一个组成部分， 两个项目。 这些战略的成功将是重要的一步 致力于开发一种有效的人类治疗方法