Janson Christopher G, Romanova Liudmila G, Leone Paola, Nan Zhenhong, Belur Lalitha, McIvor R Scott, Low Walter C
*Department of Neurosurgery, ‡Department of Neurology, ¶Department of Medicine, and ‖Genetics and Cell Biology, University of Minnesota, School of Medicine §Cell & Gene Therapy Center, University of Medicine and Dentistry of New Jersey School of Medicine.
Neurosurgery. 2014 Jan;74(1):99-111. doi: 10.1227/NEU.0000000000000157.
Hurler disease (mucopolysaccharidosis type I [MPS-I]) is an inherited metabolic disorder characterized by deficiency of the lysosomal enzyme α-L-iduronidase (IDUA). Currently, the only therapies for MPS-I, enzyme replacement and hematopoietic stem cell transplantation, are generally ineffective for central nervous system manifestations.
To test whether brain-targeted gene therapy with recombinant adeno-associated virus (rAAV5)-IDUA vectors in an MPS-I transgenic mouse model would reverse the pathological hallmarks.
Gene therapy approaches were compared using intraventricular or endovascular delivery with a marker (rAAV5-green fluorescent protein) or therapeutic (rAAV5-IDUA) vector. To improve the efficiency of brain delivery, we tested different applications of hyperosmolar mannitol to disrupt the blood-brain barrier or ependymal-brain interface.
Intraventricular delivery of 1 × 10 viral particles of rAAV5-IDUA with systemic 5 g/kg mannitol co-administration resulted in IDUA expression throughout the brain, with global enzyme activity >200% of the baseline level in age-matched, wild-type mice. Endovascular delivery of 1 × 10 viral particles of rAAV5-IDUA to the carotid artery with 29.1% mannitol blood-brain barrier disruption resulted in mainly ipsilateral brain IDUA expression and ipsilateral brain enzyme activity 42% of that in wild-type mice. Quantitative assays for glycosaminoglycans showed a significant decrease in both hemispheres after intraventricular delivery and in the ipsilateral hemisphere after endovascular delivery compared with untreated MPS-I mice. Immunohistochemistry for ganglioside GM3, another disease marker, showed reversal of neuronal inclusions in areas with IDUA co-expression in both delivery methods.
Physiologically relevant biochemical correction is possible with neurosurgical or endovascular gene therapy approaches for MPS-I. Intraventricular or endovascular delivery of rAAV5-IDUA was effective in reversing brain pathology, but in the latter method, effects were limited to the ipsilateral hemisphere.
胡勒氏病（黏多糖贮积症I型 [MPS-I]）是一种遗传性代谢紊乱疾病，其特征为溶酶体酶α-L-艾杜糖醛酸酶（IDUA）缺乏。目前，MPS-I的唯一治疗方法，即酶替代疗法和造血干细胞移植，对中枢神经系统表现通常无效。
在MPS-I转基因小鼠模型中，测试用重组腺相关病毒（rAAV5）-IDUA载体进行脑靶向基因治疗是否能逆转病理特征。
使用标记物（rAAV5-绿色荧光蛋白）或治疗性（rAAV5-IDUA）载体，通过脑室内或血管内给药比较基因治疗方法。为提高脑内给药效率，我们测试了高渗甘露醇破坏血脑屏障或室管膜-脑界面的不同应用方式。
脑室内注射1×10个rAAV5-IDUA病毒颗粒并同时全身给予5 g/kg甘露醇，导致全脑IDUA表达，总体酶活性高于年龄匹配的野生型小鼠基线水平的200%。向颈动脉血管内注射1×10个rAAV5-IDUA病毒颗粒，同时破坏29.1%的血脑屏障，主要导致同侧脑IDUA表达，同侧脑酶活性为野生型小鼠的42%。糖胺聚糖定量分析显示，与未治疗的MPS-I小鼠相比，脑室内给药后两个半球以及血管内给药后同侧半球的糖胺聚糖均显著减少。另一种疾病标志物神经节苷脂GM3的免疫组织化学显示，在两种给药方法中，IDUA共表达区域的神经元包涵体均有逆转。
对于MPS-I，采用神经外科或血管内基因治疗方法有可能实现生理相关的生化纠正。脑室内或血管内注射rAAV5-IDUA可有效逆转脑部病理，但在后一种方法中，效果仅限于同侧半球。
