Macrophage-Mediated Gene Delivery of Neurotrophic Factors in Parkinson's Disease

摘要 帕金森氏病(PD)神经保护疗法的发展将是一种主要的治疗方法 进步，特别是对我们的退伍军人来说。胶质细胞系衍生神经营养因子(GDNF)已被证明是 对帕金森病中受影响的多巴胺(DA)神经元最有效的保护营养分子。GDNF需要CNS 因为它不会穿过血脑屏障(BBB)。不幸的是，GDNF治疗帕金森病的临床试验 患者给出的结果好坏参半。向所有退化性疾病提供治疗水平的GDNF是具有挑战性的 由于人脑和大脑中的靶区较大，使用传统手术方法的黑质纹状体神经元 这种分子对脑组织的渗透性很差。我们开发了一种新的方法，能够解决 这些问题：基于造血干细胞移植(HSCT)的巨噬细胞介导的GDNF 送货。这种独特的方法利用了巨噬细胞的自然属性，即归巢到 神经元变性，利用我们强大的巨噬细胞特异性合成启动子(MSP)，以及 实施造血干细胞基因治疗的最新进展。我们以前的工作使用传统的HSCT可重复性 证明了我们的方法在各种(急性和慢性，以及神经毒素诱导的和 遗传)帕金森病小鼠模型。然而，传统的HSCT需要毒性的预适应，如辐射 因此可能不适合我们患有帕金森病的退伍军人。在上一个资金周期中，我们推出了我们最新的 发展了一种新型的非细胞毒性造血干细胞移植方法。使用这个新的系统，我们再次从基因上证明了 基因工程的HSC来源的巨噬细胞渗透到脑实质并聚集在病变部位 提供持续的局部GDNF传递，导致显著减少脑内DA神经元的变性 帕金森病小鼠黑质。关键的是，这种保护最终会改善电机和非电机 功能障碍，是可以实现的，几乎没有明显的副作用。在这项拨款申请中，我们建议研究 这种新的基于HSCT的方法来确定保护和 最佳治疗剂量。这种新型干预措施的有效性将在另一种帕金森病模型中得到验证。 最后，将应用单细胞RNAseq测序来描述分子和细胞机制 这一新的神经保护疗法的基础。这项拟议的研究将为 开发我们治疗帕金森病的创新疾病修正疗法。

Abstract The development of a neuroprotective therapy for Parkinson's disease (PD) would be a major therapeutic advance, particularly for our veterans. Glial cell line-derived neurotrophic factor (GDNF) has been shown to be the most potent protective trophic molecule to dopamine (DA) neurons affected in PD. GDNF requires CNS delivery as it does not cross the blood-brain barrier (BBB). Unfortunately, clinical trials of GDNF therapy in PD patients have given mixed results. It is challenging to deliver therapeutic levels of GDNF to all degenerating nigrostriatal neurons using traditional surgical approaches due to the large target area in the human brain and the poor brain tissue penetration of this molecule. We have developed a novel approach capable of resolving these problems: hematopoietic stem cell (HSC) transplantation (HSCT)-based macrophage-mediated GDNF delivery. This unique approach takes advantage of macrophages’ natural property of homing to sites of neuronal degeneration, capitalizes on our powerful macrophage-specific synthetic promoter (MSP), and implements recent advances in HSC gene therapy. Our previous work using conventional HSCT reproducibly demonstrated the effectiveness of our approach in various (acute and chronic, and neurotoxin induced and genetic) mouse models of PD. However, conventional HSCT requires toxic preconditioning such as irradiation and thus may not be suitable for our veterans with PD. In the last funding cycle, we introduced our newly developed novel non-cytotoxic HSCT method. Using this novel system, we again demonstrated that genetically engineered HSC-derived macrophages infiltrate the brain parenchyma and accumulate at diseased sites to provide sustained focal GDNF delivery that leads to dramatically reduced degeneration of DA neurons in the substantia nigra of PD mice. Critically, this protection ultimately results in amelioration of motor and non-motor dysfunction and is achievable with little apparent adverse effects. In this grant application, we propose to study the dose-effect relationship of this novel HSCT-based approach to identify key correlates of protection and the optimum therapeutic dose. The efficacy of this novel intervention will be validated in an additional model of PD. Finally, single-cell RNAseq sequencing will be applied to delineate the molecular and cellular mechanisms underlying this novel neuroprotective therapy. The proposed study will provide another important step in the development of our innovative disease-modifying treatment for PD.