An Approach to Dopamine Graft Augmentation

描述(申请人提供)：替代纹状体多巴胺(DA)仍然是帕金森病(PD)治疗的主要目标。许多替代左旋多巴疗法的治疗方法正在测试中。其中包括移植来自胎儿捐赠者或干细胞的未成熟DA神经元。这种方法在概念上仍然很有吸引力，特别是对于晚期帕金森病，在这种情况下，依赖剩余神经元可塑性的治疗不太可能有效。使用细胞植入物的主要问题是移植的DA神经元存活率极低和/或移植后DA表型不稳定。在过去的几年里，我们已经确定了几种分子，它们可以增强培养和移植的胎儿DA神经元的存活和功能。这些分子中的许多分子改善了对DA神经元活性的不同威胁的负面影响。这项建议的目标是系统地评估这些因素的组合，以制定一种治疗方法，以优化移植的DA神经元的存活和功能。这种最佳的方法将减少治疗效果所需的细胞数量，提高移植物成分的标准化，并有可能丰富与纹状体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含有中脑主要DA神经元类型的混合物：A9型和A10型。最近的研究表明，只有A9型神经元在移植后重新支配纹状体。因此，我们对增强效应的分析将集中于确定特定的联合疗法是否特定地丰富了相关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神经元存活和功能方面单独有效：SO2A条件培养液(神经营养支持)、血管内皮生长因子(VEGF)(神经营养支持)、褪黑素(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)。我们将利用细胞培养和移植在DA耗竭的大鼠中进行一系列实验，以制定一种多因素的方法来促进移植的胎儿DA神经元和来源于人类胚胎干细胞的DA神经元的存活和稳定的DA表型。通过优化，细胞替代疗法可能成为晚期帕金森病的一种实用治疗选择。

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.