Pathogenesis Informs Therapy for Glycosphingolipid and Glycoprotein Disorders

鞘糖脂和糖蛋白疾病单位的使命是了解鞘糖脂和糖蛋白降解中罕见疾病的疾病进展和分子发病机制。 了解这些超罕见的，常染色体隐性遗传的，一致致命的疾病，我们相信将提供一个窗口，了解更常见的神经退行性疾病。 该单位的实验室和临床项目紧密结合，并允许生成和测试新的假设和治疗。 博士后研究员Ted Han博士对转录因子EB（TFEB）的功能获得和丧失的后果进行了全基因组筛选，TFEB是溶酶体生物发生和功能的主要调节因子。 调节TFEB活性的途径可能代表了多发性溶酶体疾病中药物干预的位点。 通过使用CRISPR/Cas9技术，研究人员Raluca Nicolai博士创建了一个GM 1神经节苷脂沉积症的小鼠模型，并通过广泛的表型分析证明它与我们的II型GM 1患者最相似。 与NIH小鼠成像设施（MIF）的合作者一起，她在疾病进展的关键时间点对活小鼠进行了磁共振成像（MRI），磁共振波谱（MRS）和功能性MRI;这是NIH MIF的第一次。 我们的总体自然史研究已经招募了100多名患有GM 1和GM 2神经节苷脂沉积症（Tay-Sachs（TSD）和Sandhoff病（SD））、唾液酸沉积症和半乳糖唾液酸沉积症的患者。 我们维护并向合作者提供血液，尿液，脑脊液和原代成纤维细胞的大型生物储存库，并在可能的情况下，死者的组织。 在一个合作项目中，Han博士和Nicoli博士对两个17周妊娠胎儿的4个大脑区域进行了转录组分析，这些胎儿具有TSD和年龄匹配的对照组织，发现TSD大脑在许多转录物中存在缺陷，特别是神经元突触形成。 这与我们先前的工作一致，显示来自婴儿Sandhoff病患者的iPS细胞的人脑类器官缺乏神经元分化。 GM 2婴儿早期脑发育的显著差异将对这些患者的治疗类型和时机产生明显影响，并可能扩展到其他涉及大脑的溶酶体贮积症。 从自然史研究中收集的数据为GM 1和GM 2疾病的疾病进展提供了新的理解，我们已经发表了对这两种疾病的综述。 自然史研究还阐明了目前正在进行的两项干预性试验的可靠结局指标。 NCT 03952637是第一种用于治疗I型和II型GM 1神经节苷脂沉积症儿童的人体静脉注射AAV 9-GLB 1基因疗法。 这项研究是他与同事米格尔·塞纳-埃斯特维斯博士和石楠·格雷-爱德华兹博士在美国加州大学的10年合作的成果。马萨诸塞州医学院，道格马丁博士在奥本大学。 在初级临床医生Precilla DSouza博士和研究护士Jean约翰斯顿的指导下，12名患者安全地接受了基因转移。 结果测量现在延伸到基因治疗后三年。 正在准备其他载体，2/3期关键试验正在规划阶段。 NCT 04221451是由Sanofi Genzyme申办的AMETHIST研究，该研究使用了一种专有的底物还原分子，该分子可穿过血脑屏障并阻断神经节苷脂合成的第一个关键步骤。 我单位是试验的牵头单位，根据合作研究和数据共享协议，为试验设计和结局测量提供患者数据。 研究护士Andrea Ashton，初级临床医生Catherine格罗登和神经科医生Camilo Toro博士监督这项多国研究中最大的GM 2患者队列。

The mission of the Glycosphingolipid and Glycoprotein Disorders Unit is to understand the disease progression and molecular pathogenesis of rare disorders in glycosphingolipid and glycoprotein degradation. Understanding these ultra-rare, autosomal recessive, uniformly fatal disorders we believe will provide a window to understanding more common neurodegenerative disorders. The laboratory and clinical programs of the unit are tightly coupled and allow for the generation and testing of new hypotheses and treatments. Postdoctoral fellow Dr. Ted Han has conducted a genome-wide screen for consequences in gain and loss-of-function of transcription factor EB (TFEB) a master regulator of lysosomal biogenesis and function. Pathways which modulate TFEB activity may represent sites for pharmacologic intervention in multiple lysosomal disorders. By using CRISPR/Cas9 technologies, research fellow Dr. Raluca Nicolai has created a mouse model of GM1 gangliosidosis and with extensive phenotyping has demonstrated that it most closely resembles our Type II GM1 patients. With collaborators from the NIH Mouse Imaging Facility (MIF), she has performed magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS) and functional MRI on live mice at key timepoints in disease progression; a first for the NIH MIF. Our overarching natural history study has enrolled over 100 patients with GM1 and GM2 gangliosidosis (Tay-Sachs (TSD) and Sandhoff diseases (SD)), sialidosis, and galactosialidosis. We maintain and make available to collaborators a large biorepository of blood, urine, cerebrospinal fluid, and primary fibroblasts and, when possible, tissues on deceased patients. In a collaborative project, Drs. Han and Nicoli have performed transcriptome analysis on 4 brain regions from two 17-week gestation fetuses with TSD and age-matched control tissues and found that TSD brains are deficient in many transcripts notably neuronal synapse formation. This aligns with our previous work showing lack of neuronal differentiation in human cerebral organoids derived from iPS cells from a patient with infantile Sandhoff disease. Significant differences in early brain development of GM2 infants will have obvious implications for type and timing of therapy for these patients and may extend to other lysosomal storage disorders involving the brain. Data collected from the natural history study has provided new understanding of disease progression in GM1 and GM2 disease and we have published reviews on both disorders. The natural history study has also elucidated robust outcome measures for two interventional trials currently in progress. NCT03952637 is a first-in-human intravenous AAV9-GLB1 gene therapy for children with Type I and II GM1 gangliosidosis. The study was the culmination of a 10-year collaboration with colleagues Dr. Miguel Sena-Esteves and Dr. Heather Gray-Edwards at U. Massachusetts Medical School, Dr. Doug Martin at Auburn University. Under the guidance of primary clinician Dr. Precilla DSouza and research nurse Jean Johnston, twelve patients have safely received the gene transfer. Outcome measures now extend to three years post gene therapy. Additional vector is being prepared and a phase 2/3 pivotal trial is in the planning stages. NCT04221451, the AMETHIST Study, sponsored by Sanofi Genzyme utilizes a proprietary substrate reduction molecule that crosses the blood brain barrier and blocks the first committed step in ganglioside synthesis. Our Unit is the lead site for the trial and furnished the patient data for trial design and outcome measures under cooperative research and data sharing agreements. Research nurse Andrea Ashton, primary clinician Catherine Groden, and neurologist Dr. Camilo Toro oversee the largest cohort of GM2 patients in this multi-national study.