Manipulating N-acetyl-L-aspartate to reverse Canavan leukodystrophy

操纵 N-乙酰基-L-天冬氨酸逆转 Canavan 脑白质营养不良

• 批准号: 10026520
• 负责人: David E. Pleasure
• 金额: $ 43.18万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10026520
• 关键词: Acetates; Acetyltransferase; Address; Adult; Affinity; Amino Acids; Antisense Oligonucleotides; Aspartate; Aspartoacylase; Astrocytes; Ataxia; Brain; Canavan Disease; Catabolism; Cell membrane; Cerebellar degeneration; Child; Childhood; Cleaved cell; Clinical; Coupled; Data; Diagnosis; Disabled Children; Disease model; Enzymes; Infant; Inherited; Knock-out; Mediating; Mus; Mutation; Myelin; N-acetylaspartate; Neurologic Deficit; Neurons; Oligodendroglia; Process; Recurrence; Reporting; Role; Sodium; Testing; Therapeutic; Time; Translating; Treatment Protocols; Vacuole; Work; antisense nucleic acid; base; dicarboxylate; early onset; effective therapy; gene therapy; infancy; knock-down; leukodystrophy; locked nucleic acid; mouse model; neonatal brain; neuron loss; novel; postnatal; prevent; pup; symporter; therapeutic target; trafficking; young adult

Canavan disease is an as yet incurable leukodystrophy of infancy and childhood, in which ASPA mutations prevent brain expression of functional aspartoacylase. Aspartoacylase is required for cleavage of the abundant brain amino acid N-acetyl-L-aspartate (NAA); hence, the brain concentration of NAA becomes massively elevated in Canavan disease. This project will evaluate the fundamental hypothesis that brain maldistribution of excess NAA in Canavan disease causes brain vacuolar degeneration and leads to delayed brain neuron loss. Our prior work provided some support for this hypothesis; we reported that constitutive deletion or neonatal brain knockdown of Nat8l, which encodes the neuronal NAA-synthesizing enzyme N-acetyltransferase 8-like, prevents aspartoacylase-deficient Canavan model mouse pups from developing vacuolar leukodystrophy. And, in preliminary studies, we’ve shown that intracisternal administration of an anti-Nat8l single-stranded locked nucleic acid antisense oligonucleotide (“Nat8l gapmer”) to young adult Canavan model mice reverses their pre-existing ataxia and vacuolar cerebellar degeneration. Specific Aim 1 will determine whether an Nat8l gapmer-based treatment regimen can be devised that will provide adult Canavan model mice with long-term protection against vacuolar leukodystrophy and neuron loss. If so, this approach might be translatable to infants and children with symptomatic Canavan disease. Specific Aim 2 focuses on the hypothesis that vacuolar leukodystrophy in Canavan model mice is preventable and reversible by inhibiting astroglial over-accumulation of NAA. We will test a prediction, based on this hypothesis, that vacuolar leukodystrophy in Canavan model mice can be prevented or reversed, respectively, by constitutive or astroglial conditional Slc13a3 deletion; Slc13a3 encodes a plasma membrane sodium-coupled dicarboxylate cotransporter (NaDC3) expressed by astroglia that has high affinity for NAA. A positive result in this aim would identify Slc13a3 and NaDC3 as novel Canavan disease therapeutic targets.

Canavan病是婴儿期和童年时期无法治愈的白细胞营养不良，其中ASPA 突变阻止了功能性天冬酰酶的大脑表达。需要阿斯帕托酰基。 丰富的脑氨基酸N-乙酰基 - 甲酸天冬氨酸（NAA）的切割；因此，大脑 在Canavan疾病中，NAA的浓度大大升高。这个项目将评估 基本的假设是，在Canavan疾病原因中脑部过多的NAA脑分布 脑真空变性，导致脑神经元丧失延迟。我们先前提供的工作 对这一假设的一些支持；我们报道了本构缺失或新生儿大脑 NAT8L的敲低，它编码神经元NaA合成酶N-乙酰基转移酶 8类，防止aspartoyacylase缺陷型canavan型鼠标幼崽开发真空 白细胞营养不良。而且，在初步研究中，我们表明，肠内给药 抗NAT8L单链锁定的核酸反义寡核苷酸（“ Nat8l Gapmer”）至 年轻的成年迦南模型小鼠逆转其先前存在的共济失调和液泡小脑 退化。特定的目标1将确定基于NAT8L Gapmer的治疗方案是否 可以设计将为成年Canavan模型小鼠提供长期保护 吸尘白细胞营养不良和神经元丧失。如果是这样，这种方法可能可以翻译成婴儿 和有症状的山羊病的儿童。具体目标2侧重于以下假设 Canavan模型小鼠中的液泡白细胞营养不良是可以通过抑制来预防和可逆的 NAA的星形胶质细胞过度累积。我们将基于这一假设测试一个预测，即 Canavan模型小鼠中的真空性白细胞营养不良，分别可以通过 组成型或星形胶质条件SLC13A3缺失； SLC13A3编码质膜 星形胶质细胞表达的钠偶联二羧酸二羧酸二羧酸盐共转运蛋白（NADC3）高亲和力 对于naa。这个目标的积极结果将识别SLC13A3和NADC3为新型Canavan 疾病疗法靶标。