Next Generation Treatment for Krabbe Disease

克拉贝病(Globoid细胞白质营养不良症，GLD)是一种遗传性儿童疾病，由脑白质细胞缺乏引起 溶酶体酶，半乳糖神经酰胺酶(GALC)。在缺乏GALC活性的情况下，具有高度的细胞毒性 脂质，半乳糖-鞘氨醇(精神病素，Psy)积聚并优先导致 少突胶质细胞。Krabbe病影响中枢(CNS)和外周神经系统(PNS)，导致 易怒、感觉退化、运动缺陷、癫痫发作和认知障碍从6个月大开始 死亡发生在2-5岁。目前还没有有效的治疗Krabbe病的方法。在……里面 此外，多年来对Krabbe病真实动物模型的所有研究证据表明，没有 单一治疗提供了有意义的长期好处。然而，我们最近展示了一种组合 同时针对主要致病机制(GALC缺乏症)和 GALC缺乏的次要后果(精神积聚、炎症等)显著和 协同增效。尽管100多年前就描述了克拉贝病，而小鼠 模型已有近40年的历史，但令人惊讶的是，我们对其发病机制知之甚少 疾病。这在很大程度上是由于交叉修正的混杂效应造成的。我们创造了一种嵌合形式的 GALC保持酶活性，防止精神药物积累，不能交叉 更正周围的单元格。这种新试剂现在将使我们能够确定交叉剂的贡献 纠正各种治疗策略和特定细胞类型在Krabbe发病机制中的作用 疾病。这项提案的目标是1)确定新开发的底物还原的效果 治疗药物单独和组合，2)确定某些治疗方法相互作用的机制/S 协同增效，3)确定特定细胞类型在Krabbe发病机制中的作用 疾病，以及4)确定产生精神药物的机制/S，并可能发现一种新的 底物还原目标。我们将以以下具体目标实现这些目标： 目的1：我们将确定CGT特异性SRT药物BMNS202单独和联合治疗的疗效。 联合造血干细胞移植和AAV介导的基因治疗。 目的2：我们将确定HSCT在与CNS导向的AAV-1联合时观察到的协同作用的作用。 Krabbe病小鼠模型的介导性基因治疗。 目的3：我们将确定特定细胞类型在Krabbe病发病机制中的作用。 目的4：我们将确定酸性神经酰胺酶在精神病素分解代谢产物中的作用。 克雷伯病的发病机制。

Krabbe disease (Globoid-cell leukodystrophy, GLD) is an inherited childhood disease caused by a deficiency in the lysosomal enzyme, galactosyl-ceramidase (GALC). In the absence of GALC activity a highly cytotoxic lipid, galactosyl-sphingosine (psychosine, Psy) accumulates and preferentially causes the death of oligodendrocytes. Krabbe disease affects the central (CNS) and peripheral nervous systems (PNS) leading to irritability, sensory deterioration, motor defects, seizures, and cognitive deficits beginning at 6 months of age and death occurs by 2-5 years of age. There is currently no effective therapy for Krabbe disease. In addition, all the evidence from years of research in authentic animal models of Krabbe disease shows that no single treatment provides meaningful long-term benefits. However, we recently showed that a combination therapy approach that simultaneously targets the primary pathogenic mechanism (GALC deficiency) and secondary consequences of GALC deficiency (psychosine accumulation, inflammation, etc) dramatically and synergistically increases efficacy. Although Krabbe disease was described over 100 years ago and the murine model has been available for nearly 40 years, we know surprisingly little about the pathogenesis of the disease. This is largely to the confounding effects of cross-correction. We have created a chimeric form of GALC that retains enzyme activity, prevents the accumulation of psychosine and is incapable of cross- correcting surrounding cells. This novel reagent will now enable us to determine both the contribution of cross- correction to various therapeutic strategies and the role of specific cell types in the pathogenesis of Krabbe disease. The goals of this proposal are to 1) determine the efficacy of newly developed substrate reduction therapy drugs alone and in combination, 2) determine the mechanism/s by which certain therapies interact to synergistically increase efficacy, 3) determine the role of specific cell types in the pathogenesis of Krabbe disease, and 4) determine the mechanism/s by which psychosine is generated and potentially uncover a new substrate reduction target. We will accomplish these goals with the following Specific Aims: Aim 1: We will determine the therapeutic efficacy of a CGT-specific SRT drug, BMNS202, alone and in combination with HSCT and AAV-mediated gene therapy. Aim 2: We will determine the role of HSCT in the synergy observed when combined with CNS-directed AAV- mediated gene therapy in the murine model of Krabbe disease. Aim 3: We will determine the role of specific cell types in the pathogenesis of Krabbe disease. Aim 4: We will determine the role of acid ceramidase in the catabolic production of psychosine and the pathogenesis of Krabbe disease.