GANGLIOSIDE-TROPHIC FACTOR--INTERACTIVE MECHANISM

该项目的长期目标是了解分子 在创伤后神经再生的机制。 严重脊髓损伤后功能恢复的一个重要方面 是轴突发芽（轴突发生）。 实验证据表明 多种营养因子（其中之一是神经节苷脂）可以刺激 在体内和体外的轴突发生。 这产生 在可能使用神经节苷脂作为治疗的相当大的兴趣 用于临床治疗脊髓损伤的药物。 虽然 神经节苷脂促进轴突发生的分子机制 我们和其他人的结果表明，神经节苷脂 可影响整个细胞和破碎细胞的蛋白磷酸化 准备工作 本提案中描述的实验旨在 测试我们的一般假设，即神经节苷脂发挥其作用， 通过调节神经元的轴突发生和神经元增殖 特定蛋白质的磷酸化状态。 我们将采用的主要模型 使用的是SH-SY 5 Y神经母细胞瘤细胞系，但验证结果表明， 将使用PC 12细胞进行一些实验。 首先，我们将研究 神经节苷脂与血小板源性生长的相互作用 胰岛素样生长因子-I（IGF-I）和胰岛素对SH- SY 5 Y细胞增殖。 第二，我们将研究 不同神经节苷脂对神经生长因子刺激的SH-SY 5 Y细胞突起形成的影响 在存在PDGF、IGF-I和胰岛素的情况下。 第三，我们将确定 特异性神经节苷脂对三种不同的 我们提出的激酶系统在这些过程中起着关键作用， 生物过程：a）由PDGF、IGF-I刺激的酪氨酸激酶和 胰岛素; B）蛋白激酶-C; c）cAMP依赖性蛋白激酶。 结果 通过这些实验产生的结果应该对 神经节苷脂促进轴突发生的分子机制。 这些知识对于理解神经系统的 再生研究在分子水平上，并在设计新的 治疗脊髓损伤患者的治疗策略。

The long range goal of this project is to understand at the molecular level the mechanisms involved in neural regeneration following trauma. A critical aspect of functional recovery from severe spinal cord injury is axonal sprouting (neuritogenesis). Experimental evidence indicates that several trophic factors, one of which is ganglioside, can stimulate neuritogenesis both in vivo and in vitro. This has generated considerable interest in the possible use of gangliosides as therapeutic agents for clinical treatment of spinal cord injuries. Although the molecular mechanisms through which gangliosides promote neuritogenesis are not known, results of ours and others have shown that gangliosides can affect protein phosphorylation in whole cell and broken cell preparations. Experiments described in this proposal were designed to test our general hypothesis that gangliosides exert their effects on neuritogenesis and neuronal proliferation by modulating the phosphorylation states of specific proteins. The main model that we will use is the SH-SY5Y neuroblastoma cell lines, but confirmatory results of some experiments will be sought using PC12 cells. First, we will study the interactive effects of gangliosides with platelet-derived growth factor (PDGF), insulin-like growth factor-I (IGF-I), and insulin on SH- SY5Y cell proliferation. Second, we will examine the effects of different gangliosides on NGF-stimulated neuritogenesis of SH-SY5Y cells in the presence of PDGF, IGF-I, and insulin. third, we will determine the differential effects of specific gangliosides on three different kinase systems which we propose are critically involved in these biological processes: a) Tyrosine kinase stimulated by PDGF, IGF-I and insulin; b) Protein kinase-C; c) cAMP-dependent protein kinase. Results generated by these experiments should yield considerable insight into the molecular mechanisms through which gangliosides promote neuritogenesis. This knowledge will be of considerable value in understanding neural regeneration studied at the molecular level and in designing new therapeutic strategies for treatment of spinal cord injured patients.