New approach for cholesterol and sphingolipid reduction in Niemann-Pick C1 disease

降低尼曼-匹克 C1 病胆固醇和鞘脂的新方法

基本信息

批准号：
10078545
负责人：
Jason Charles Newton
金额：
$ 16.55万
依托单位：
VIRGINIA COMMONWEALTH UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-12-25 至 2022-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10078545
关键词：
Address Agreement Autophagocytosis Behavioral Symptoms Binding Brain CRISPR/Cas technology Catabolism Cells Cerebellum Child Childhood Cholesterol Clinical Trials Cognition Combined Modality Therapy Complex Data Defect Development Disease Disease Progression Dose Enzymes Epigenetic Process Fibroblasts Functional disorder Genes Goals Histone Deacetylase Histone Deacetylase Inhibitor Homeostasis Human Knowledge Life Extension Life Support Care Lipids Liver Longevity Lysosomes Mediating Mediator of activation protein Membrane Memory Mentors Metabolic Pathway Metabolism Molecular Molecular Genetics Monitor Motor Skills Movement Mus Mutant Strains Mice Mutation NPC1 gene National Institute of Child Health and Human Development Nerve Degeneration Neurologic Nuclear Pathogenesis Pathogenicity Pathology Patients Pharmacology Phase Phenotype Play Process Proteins Publishing Regulation Research Role SPHK1 enzyme Sphingolipids Sphingosine Supraoptic Vertical Ophthalmoplegia System Techniques Therapeutic Training Work base cholesterol trafficking citrate carrier clinically relevant disease-causing mutation effective therapy human disease improved outcome in vivo innovation late endosome liver function mouse model multiple sclerosis treatment mutant mutant mouse model neuroinflammation neuropathology novel novel strategies novel therapeutic intervention overexpression programs progressive neurodegeneration restoration sphingosine 1-phosphate sphingosine kinase targeted treatment therapeutic evaluation trafficking treatment strategy

项目摘要

Niemann-Pick Type C (NPC) is fatal lipid storage disease caused by mutations in NPC1 (95%) and NPC2 (5%) genes. NPC is characterized by cholesterol and sphingolipid accumulation, complex progressive neurodegeneration, and a lifespan of less than 20 years. NPC1/2 function in late endosomes/lysosomes (LE/L), with soluble NPC2 binding unesterified cholesterol and transferring it to integral membrane NPC1 that facilitates its movement out of the LE/L. Recently it was discovered that HDAC inhibition can epigenetically increase expression of the low activity NPC1mut protein to levels that can correct the cholesterol defect. However, HDAC inhibitors now being tried for treatment NPC do not get into the CNS and do not treat the neurological sequelea of NPC. My published results, however, suggest that FTY720/Fingolimod, used for treatment of multiple sclerosis, is also a HDAC inhibitor that increases expression of NPC1/2 and corrects cholesterol and sphingolipid storage defects in NPC1mut fibroblasts. Furthermore, my preliminary data in mice show that FTY720 does accumulate in the cerebellum, increases NPC1/2 expression in brain as well as liver, and reduces cholesterol levels. Hence, in my first Aim, I will extend this approach to an in vivo mouse model of NPC that more accurately mimics the human disorder, monitoring brain and liver NPC1/2 expression, cholesterol and sphingolipid homeostasis, and disease progression. While accumulation of sphingolipids have been implicated in development of NPC-associated neurological defects, the mechanisms remain unknown. Recent published work and my preliminary data support the premise that a deficiency of sphingosine kinase 1 (SphK1), which converts the sphingolipid metabolite sphingosine to the bioactive mediator sphingosine-1- phosphate, may be important in pathogenesis of NPC. Consequently, my Aim 2a focuses on the role of SphK1 in sphingolipid accumulation on a cellular level through a detailed examination of its expression, localization, and regulation in NPC mutant fibroblasts. Furthermore, by employing a novel SphK1 activator we recently discovered, and CRISPR CAS9 mediated modulation of SphK1 expression and activity, I will examine whether increasing sphingolipid catabolism suppresses the NPC cellular phenotype. Finally, most therapeutic approaches focus on reducing cholesterol accumulation, but our preliminary data suggest that cholesterol and sphingolipid metabolic pathways are interdependent, decreased SphK1 activity leads to accumulation of both sphingolipids and cholesterol. Therefore, I will examine the benefits of targeting both cholesterol and sphingolipid accumulation through a novel “dual lipid” reduction strategy in a mouse model of NPC. I expect that my results will validate the use of FTY720/Fingolimod to effectively restore normal NPC1/2 activity levels, answer longstanding questions about the mechanism of sphingolipid accumulation in NPC, and pave the way for a new therapeutic strategy targeting both pathogenic classes of lipids in NPC disease.

Niemann-Pick C 型 (NPC) 是一种致命的脂质贮积病，由 NPC1 (95%) 和 NPC2 (5%) 突变引起 NPC的特点是胆固醇和鞘脂积累，复杂进行性。神经退行性变，NPC1/2 在晚期内体/溶酶体中发挥作用的寿命不足 20 年。 (LE/L)，可溶性NPC2结合未酯化的胆固醇并将其转移至整合膜NPC1，最近发现 HDAC 抑制可以通过表观遗传学的方式促进其移出 LE/L。将低活性 NPC1mut 蛋白的表达增加到可以纠正胆固醇缺陷的水平。然而，目前尝试用于治疗鼻咽癌的 HDAC 抑制剂不会进入中枢神经系统，也不能治疗鼻咽癌。然而，我发表的结果表明，FTY720/芬戈莫德用于治疗鼻咽癌的神经系统后遗症。治疗多发性硬化症，也是一种 HDAC 抑制剂，可增加 NPC1/2 的表达并纠正 NPC1mut 成纤维细胞中的胆固醇和鞘脂储存缺陷此外，我在小鼠中的初步数据。表明 FTY720 确实在小脑中积累，增加了大脑和肝脏中 NPC1/2 的表达，因此，在我的第一个目标中，我将把这种方法扩展到体内小鼠模型。 NPC 更准确地模仿人类疾病，监测大脑和肝脏 NPC1/2 的表达，胆固醇和鞘脂的稳态，以及鞘脂的积累与疾病进展有关。与鼻咽癌相关的神经缺陷的发生有关，但其机制仍不清楚。最近发表的工作和我的初步数据支持以下前提：鞘氨醇激酶 1 缺乏 (SphK1)，它将鞘脂代谢物鞘氨醇转化为生物活性介质鞘氨醇-1- 磷酸盐可能在 NPC 的发病机制中发挥重要作用，我的目标 2a 重点关注 SphK1 的作用。通过详细检查鞘脂的表达、定位，在细胞水平上观察鞘脂的积累，此外，我们最近使用了一种新型 SphK1 激活剂。发现了 CRISPR CAS9 介导的 SphK1 表达和活性的调节，我将检查是否最后，增加鞘脂分解代谢可抑制 NPC 细胞表型。方法的重点是减少胆固醇积累，但我们的初步数据表明胆固醇和鞘脂代谢途径是相互依赖的，SphK1 活性降低会导致两者的积累因此，我将研究针对胆固醇和胆固醇的好处。我期望通过一种新型的“双脂质”减少策略在 NPC 小鼠模型中实现鞘脂积累。我的结果将验证使用 FTY720/Fingolimod 可以有效恢复正常的 NPC1/2 活动水平，回答有关鼻咽癌中鞘脂积累机制的长期疑问，并铺平道路针对鼻咽癌疾病中两种致病脂质类别的新治疗策略。