An Approach to Dopamine Graft Augmentation

描述（由申请人提供）：纹状体多巴胺（DA）的替代仍然是帕金森病（PD）治疗的主要目标。左旋多巴疗法的许多治疗替代品正在测试中。其中之一是移植来自胎儿供体或干细胞的未成熟DA神经元。这种方法在概念上仍然具有吸引力，特别是对于晚期PD，其中依赖于剩余神经元的可塑性的疗法不太可能有效。与使用细胞植入物相关的主要问题是移植的DA神经元的极差存活和/或移植后DA表型的不稳定性。在过去的几年里，我们已经确定了几个分子，增加培养和移植的胎儿DA神经元的存活和功能。这些分子中的许多改善了对DA神经元活力的不同威胁的负面影响。本提案的目标是系统地评估这些因素的组合，以制定优化移植DA神经元的存活和功能的疗法。这种最佳方法将允许减少治疗功效所需的细胞数量，提高移植物组成的标准化，并可能丰富与纹状体DA替代相关的DA神经元类型的移植物。来自胎儿或干细胞来源的细胞移植物含有中脑的主要DA神经元类型的混合物：A9型和A10型。最近的研究表明，移植后只有A9型神经元能再支配纹状体。因此，我们对增强效应的分析将集中在确定特定的组合疗法是否特异性地富集相关A9细胞类型中的DA神经元群体。我们以前的研究已经确定了以下分子在促进培养和移植的DA神经元的存活和功能方面是单独有效的：SO 2A条件培养基（神经营养支持）、血管内皮生长因子（VEGF）（神经营养，刺激血管供应）、褪黑激素（抗氧化剂）、肌酸（细胞能量）、促红细胞生成素（抗凋亡）和米诺环素（抗炎）。我们将使用一系列的实验，利用细胞培养，然后在DA-耗尽大鼠移植，制定一个多因素的方法，以促进移植的胎儿DA神经元和DA神经元来源于人胚胎干细胞的生存和稳定的DA表型。随着优化，细胞替代疗法可能成为晚期PD的实用治疗选择。

DESCRIPTION (provided by applicant): Replacement of striatal dopamine (DA) remains the main goal of therapeutics for Parkinson's disease (PD). Many therapeutic alternatives to levodopa therapy are being tested. Among these is transplantation of immature DA neurons either derived from fetal donors or stem cells. This approach continues to be conceptually attractive, especially for late stage PD in which therapies that rely upon plasticity of remaining neurons are unlikely to be effective. The main problem associated with use of cell implants is the extremely poor survival of grafted DA neurons and/or the instability of DA phenotype after grafting. Over the past several years we have identified several molecules that augment survival and function of cultured and grafted fetal DA neurons. Many of these molecules ameliorate the negative impact of distinct threats to DA neuron viability. It is the goal of this proposal to systematically evaluate combinations of these factors to formulate a therapy to optimize survival and function of grafted DA neurons. Such an optimal approach will allow reduction in the number of cells required for therapeutic efficacy, improve standardization of graft composition and potentially enrich grafts in the DA neuron type relevant for striatal DA replacement. Cell grafts derived from fetal or stem cell sources contain a mixture of the major DA neuron types of the midbrain: A9 type and A10 type. It recently has been demonstrated that only A9 type neurons reinnervate the striatum after grafting. Thus, our analysis of augmentation effects will focus upon determining whether particular combination therapies specifically enrich the DA neuron population in the relevant A9 cell type. Our previous studies have identified the following molecules to be individually effective in promoting survival and function of cultured and grafted DA neurons: SO2A conditioned medium (neurotrophic support), vascular endothelial growth factor (VEGF)(neurotrophic, stimulates vascular supply), melatonin (anti-oxidant), creatine (cellular energy), erythropoeitin (anti-apoptotic), and minocycline (anti-inflammatory). We will use a series of experiments utilizing cell culture followed by grafting in DA-depleted rats to formulate a multi-factorial approach to promoting survival and stable DA phenotype in grafted fetal DA neurons and DA neurons derived from human embryonic stem cells. With optimization, cell replacement therapy could become a practical therapeutic option for late stage PD.