Ghodsi A, Stein C, Derksen T, Yang G, Anderson R D, Davidson B L
Department of Neurosurgery, University of Iowa College of Medicine, Iowa City 52242, USA.
Hum Gene Ther. 1998 Nov 1;9(16):2331-40. doi: 10.1089/hum.1998.9.16-2331.
Mucopolysaccharidosis type VII (MPS VII), caused by beta-glucuronidase deficiency, is a classic lysosomal storage disease. In the central nervous system (CNS), there is widespread pathology with distention of vacuoles in neurons and glia. An approach to therapy for MPS VII would require extensive delivery of enzyme to the CNS and subsequent uptake by the affected cells. In this study we show that intrastriatal injection of recombinant adenovirus encoding beta-glucuronidase (Ad betagluc) to MPS VII or wild-type mice results in focal, intense beta-glucuronidase mRNA expression near the injection site. Further, histochemical staining for enzyme activity showed that beta-glucuronidase activity extended well beyond transduced cells. Activity was detected throughout the ipsilateral striatum as well as in the corpus callosum, ventricles, and bilateral neocortex. Similarly, after injection into the right lateral ventricle or cisterna magna, enzyme activity was present in the ependymal cells of the ventricles, in the subarachnoid spaces, and also in the underlying cortex (150-500 microm from ependyma). The distribution of enzyme was most extensive 21 days after gene transfer to normal mouse brain, with more than 50% of the hemisphere positive for beta-glucuronidase activity. Eighty-four days after adenovirus injection a substantial level of enzyme expression remained (>40% of hemisphere positive for beta-glucuronidase activity). Histological sections from striatum of beta-glucuronidase-deficient mice injected with Ad betagluc showed a marked reduction in the number of distended vacuoles in both neurons and glia, as compared with uninjected striatum. Importantly, correction was noted in both hemispheres. Our finding that a relatively small number of transduced cells produce enzyme that reaches a large proportion of the CNS has favorable implications in developing direct gene transfer therapies for lysosomal storage disorders.
VII型粘多糖贮积症（MPS VII）由β-葡萄糖醛酸酶缺乏引起，是一种典型的溶酶体贮积病。在中枢神经系统（CNS）中，存在广泛的病理变化，神经元和神经胶质细胞中的液泡扩张。MPS VII的治疗方法需要将大量酶递送至CNS并随后被受影响的细胞摄取。在本研究中，我们表明向MPS VII或野生型小鼠纹状体内注射编码β-葡萄糖醛酸酶的重组腺病毒（Ad betagluc）会导致注射部位附近出现局部、强烈的β-葡萄糖醛酸酶mRNA表达。此外，酶活性的组织化学染色显示β-葡萄糖醛酸酶活性远远超出转导细胞。在同侧纹状体以及胼胝体、脑室和双侧新皮质中均检测到活性。同样，在注射到右侧脑室或小脑延髓池后，脑室的室管膜细胞、蛛网膜下腔以及下层皮质（距室管膜150 - 500微米）中均存在酶活性。基因转移至正常小鼠脑21天后，酶的分布最为广泛，超过50%的半球β-葡萄糖醛酸酶活性呈阳性。腺病毒注射84天后，仍保留相当水平的酶表达（>40%的半球β-葡萄糖醛酸酶活性呈阳性）。注射Ad betagluc的β-葡萄糖醛酸酶缺陷小鼠纹状体的组织学切片显示，与未注射的纹状体相比，神经元和神经胶质细胞中扩张液泡的数量显著减少。重要的是，在两个半球均观察到了纠正情况。我们的发现，即相对少量的转导细胞产生的酶能够到达大部分CNS，这对于开发针对溶酶体贮积病的直接基因转移疗法具有积极意义。
