The presence of mutant HTLV-I in the central nervous system

近十年来，我们研究了球样细胞白质营养不良的发病机制，这是一种缺乏半乳糖神经酰胺酶I活性的遗传性脱髓鞘疾病，并报道了半乳糖神经酰胺的一种溶酶化合物半乳糖神经酰胺在患者组织中积累，并表明积累的溶酶化合物的细胞毒性导致细胞死亡和随后的脱髓鞘。在其他脂质储存疾病如GM1神经节脂质病和异色性脑白质营养不良中也有溶酶化合物的积累。对于这些脂质储存疾病的一种治疗方法，我们假设我们是否可以解毒积累的溶鞘脂，我们在这个项目中获得了一些数据如下：1。1994年，我们研究了溶鞘脂的合成途径，当将-葡萄糖苷酶的竞争性抑制剂conduritol B环氧化物（CBE）加入培养成纤维细胞的培养基中时，观察到葡萄糖-神经酰胺的一种溶酶化合物-葡萄糖-鞘脂的积累。葡萄糖葡萄糖苷的积累与添加CBE的剂量有关。接下来，我们在培养基中同时加入CBE和葡萄糖神经酰胺合成抑制剂PDMP，发现葡萄糖神经酰胺的积累已经消失。从这些数据我们得出结论，葡萄糖-鞘氨醇的合成不仅是由鞘氨醇的糖基化催化，而且是由葡萄糖-神经酰胺的去酰化催化。1995年，我们研究了溶糖鞘脂的降解途径。为此，我们对半乳糖神经酰胺酶I（半乳糖神经酰胺酶的一种降解酶）的分子特性进行了表征，并在成年血细胞白质营养不良患者中发现了突变。通过PCR扩增获得该基因的cDNA片段，并对其氨基酸编码区总核苷酸进行测序。在4例患者中，我们发现了新的点突变，取代了进化保守的氨基酸。我们现在正试图通过真核细胞中突变cDNA的表达来证实在患者中发现的突变是导致酶活性缺乏的原因。少

For these ten years we have studied the pathogenetic mechanism of globoid cell leukodystrophy, a genetic demyelinating disorder deficient in galctosylceramidase I activity, and reported that galactosylsphingosine, a lyso compound of galactosylceramide, accumulates in the tissue of the patients and suggested that the cytotoxicity of the acumulated lysocompound leads to the cell death and subsequent demyelination. We have also the accumulation of lysocompounds in other lipid storage diseases such as GM1 gangliosidosis and metachromatic leukodystrophy. For one of the treatment of these lipid storage diseases we hypothesized if we could detoxicate the accumulated lysosphingolipids, and we obtained some data on this project as follows :1. In 1994, we examined the synthetic pathway of the lysosphingolipid, When conduritol B epoxide (CBE), a competitive inhibitor of beta-glucosidase, was included in the medium of cultured fibroblasts, the accumulation of glucosylsphingosine, a lysocompound of … More glocosylceramide, was observed. The accumulated glucosylsphingosine was dependent on the dose of added CBE.Next, we added in the medium both CBE and PDMP, an inhibitor of glucosylceramide synthesis, and found the deceased accumulation of glucosylsphingosine. From these data we concluded that the synthesis of glucosylsphingosine is catalyzed not only by the glucosylation of sphingosine but also by the deacylation of glucosylceramide.2. In 1995, we examined the degradative pathway of the lysospingolipid. For this purpose, we characterized molecular properties of galactosylceramidase I, a degrading enzyme of galactosylsphingosine and found mutations in adult patients with globod cell leukodystrophy. We obtained cDNA fragments of the gene after amplification by PCR from the patients and sequenced the total nucleotides in the amino acid coding region. In the 4 patients, we found new point mutations which replace evolutionally-conserved amino acids to others. We are now atempting to confirm that the mutations found in the patients are causative for the deficiency of the enzyme activity by expression of the mutated cDNA in eucaryotic cells. Less