ECM and the Differentiation/Plasticity of DA Neurons

ECM 和 DA 神经元的分化/可塑性

• 批准号: 6474940
• 负责人: MARIANN M BLUM
• 金额: $ 27.71万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6474940
• 关键词: cell differentiation; developmental genetics; developmental neurobiology; dopamine; embryo /fetus tissue /cell culture; extracellular matrix; fibroblast growth factor; gene expression; immunocytochemistry; integrins; laboratory mouse; methylphenyltetrahydropyridine; nervous system regeneration; neural plasticity; neurogenesis; neurogenetics; neurons; neurotoxicology; substantia nigra

DESCRIPTION (provided by the applicant): We have recently shown in animal models of Parkinson's disease, a progressive neurodegenerative disorder characterized by the degeneration of nigrostriatal dopaminergic neurons, that there is a robust proliferative burst of neuroprogenitor cells in response to the loss of dopamine neurons. However, these cells remain in an undifferentiated state. We have also shown that in response to the degeneration of dopamine neurons in the substantia nigra that the remaining un-injured dopamine neurons are able to compensate for the loss by extending collateral axonal fibers. However, this compensatory response becomes greatly attenuated with increasing age. Therefore, based on these previous results we propose further experiments designed to discover how to induce the differentiation of dopaminergic progenitor cells and injury-induced collateral sprouting in animal models of Parkinson's disease. Integrins are cell surface receptors involved in cell-matrix and cell-cell adhesion interactions in salt organs and play an important role in regulating cell proliferation, survival, and process outgrowth. Studies outside the nervous system indicate that an integration of signals derived from both integrin-ECM interactions and soluble growth factors are required for cellular differentiation. Thus, we hypothesize that ECM molecules expressed in the CNS in combination with growth factors act together to induce neural progenitor cell commitment and differentiation. To test our hypothesis, we propose to characterize which ECM molecules are expressed during the time in development when midbrain dopaminergic progenitors are exiting the cell cycle and making their final commitment to the dopaminergic neuronal fate. In parallel, we plan to culture these progenitor cells on different ECM substrates in combination with fibroblast growth factor-2 (FGF-2) and determine whether the fate of these cells is regulated. We further hypothesize that as the brain develops, the expression of ECM molecules required for the differentiation of neural progenitor cells into dopaminergic neurons becomes down-regulated. To test this idea we plan to culture midbrain progenitor cells on tissue slices containing the substantia nigra from either developing or mature animals. Since our overall goal is to be able to induce dopaminergic progenitor cell differentiation in mature animals, we propose to test whether the induced expression of integrins by retroviral expression vector infection of uncommitted progenitors will induce their differentiation. Finally, we plan to test the hypothesis that age-related differences in ECM molecules play a role in supporting or inhibiting collateral sprouting. Thus, we plan to culture embryonic dopamine neurons on striatal tissue slices collected from control and MPTP mice of different age groups.

描述（由申请人提供）：我们最近在动物身上展示了 帕金森病模型，一种进行性神经退行性疾病 以黑质纹状体多巴胺能神经元变性为特征， 神经祖细胞会出现强烈的增殖爆发，以响应 多巴胺神经元的丧失。然而，这些细胞仍保留在 未分化状态。我们还表明，为了应对退化 黑质中的多巴胺神经元，其余未受伤的神经元 多巴胺神经元能够通过扩展侧支循环来补偿损失 轴突纤维。然而，这种补偿反应会大大减弱 随着年龄的增长。因此，基于这些先前的结果，我们建议 进一步的实验旨在发现如何诱导分化 动物多巴胺能祖细胞和损伤诱导的侧支萌芽 帕金森病模型。整合素是细胞表面受体，参与 盐器官中细胞-基质和细胞-细胞粘附相互作用，并发挥 在调节细胞增殖、存活和过程中发挥重要作用 生长出来的。神经系统之外的研究表明，整合 来自整合素-ECM 相互作用和可溶性生长因子的信号 是细胞分化所必需的。因此，我们假设 ECM 中枢神经系统中表达的分子与生长因子共同作用 诱导神经祖细胞定向和分化。来测试我们的 假设，我们建议表征哪些 ECM 分子在 中脑多巴胺能祖细胞退出的发育时期 细胞周期并最终决定多巴胺能神经元的命运。 与此同时，我们计划在不同的 ECM 上培养这些祖细胞 底物与成纤维细胞生长因子-2 (FGF-2) 组合并测定 这些细胞的命运是否受到调控。我们进一步假设 大脑发育，需要表达 ECM 分子 神经祖细胞分化为多巴胺能神经元 下调。为了测试这个想法，我们计划培养中脑祖细胞 在含有发育中或黑质的组织切片上 成熟的动物。由于我们的总体目标是能够诱导多巴胺能 成熟动物的祖细胞分化，我们建议测试是否 逆转录病毒表达载体感染诱导整合素表达 未定型的祖细胞将诱导其分化。最后，我们计划 检验 ECM 分子中与年龄相关的差异发挥作用的假设 支持或抑制侧枝发芽的作用。因此，我们计划培养 纹状体组织切片上的胚胎多巴胺神经元收集自对照和 不同年龄组的MPTP小鼠。