Establishment of new therapeutic strategies for neurogenetic disorders during childhood

高谢病(GD)是由β-葡萄糖苷酶(β-Glu)缺陷引起的一种最常见的鞘磷脂沉积症。我们发现，一种类似于β-Glu抑制剂的碳水化合物-辛基-β-valienamine(NOV)可以提高培养细胞中β-Glu的F213I、N188S、G202R和N370S突变形式的蛋白质水平和酶活性。当在COS细胞中表达时，突变蛋白和野生型蛋白主要定位于内质网，对Endo-H处理敏感。NOV没有改变这种定位或Endo-H敏感性，表明它作用于内质网。对不同长度的β-烷基-β-valienamines的分析表明，β-十二烷基-β-valienamine的效果与nov.这些结果提示NOV及其相关化合物对存在广泛β-Glu突变的GD具有潜在的治疗价值。C型尼曼-皮克病是一种由NPC1(NPC2)基因突变引起的脂质储存障碍。我们发现，人鼻咽癌成纤维细胞分泌多种细胞因子，并含有高水平的STATs。这些细胞还含有增加的TLR4水平。在鼻咽癌模型小鼠脑内，胶质细胞表达TLR4和IL-6，而神经胶质细胞和神经细胞均表达STATS。鼻咽癌模型小鼠的TLR4基因缺失减少了IL-6的分泌，但未能改变STAT水平或大脑中神经胶质细胞的激活。相反，IL-6的基因缺失使STAT水平正常化，并抑制了胶质细胞的激活。这些发现表明，结构性细胞因子分泌导致STATS的激活，这种分泌部分是由TLR4的内吞积聚引起的。这些结果还表明，类似的信号事件可能是鼻咽癌脑内神经胶质细胞激活的基础

Gaucher disease (GD), caused by a defect of β-glucosidase (β-Glu), is the most common form of sphingolipidosis. We found that a carbohydrate mimic β-octyl-β-valienamine (NOV), an inhibitor of β-Glu, could increase the protein level and enzyme activity of F213I, N188S, G202R and N370S mutant forms of β-Glu in cultured cells. When expressed in COS cells, the mutant proteins as well as the wild-type protein were localized predominantly in the endoplasmic reticulum and were sensitive to Endo-H treatment. NOV did not alter this localization or Endo-H sensitivity, suggesting that it acted in the endoplasmic reticulum. Profiling of β-alkyl-β-valienamines with various lengths of the acyl chain showed that β-dodecyl-β-valienamine was as effective as NOV. These results suggest a potential therapeutic value of NOV and related compounds for GD with a broad range of β-Glu mutations.Niemann-Pick disease type C (NPC) is a lipid storage disorder caused by mutations in NPC1 (NPC2) genes. We found that human NPC fibroblasts secrete several cytokines and contain increased levels of STATs. These cells also contained increased levels of TLR4. In the NPC model mouse brain, glial cells expressed TLR4 and IL-6, whereas both glial and neuronal cells expressed STATs. Genetic deletion of TLR4 in NPC model mice reduced IL-6 secretion but failed to alter STAT levels or glial cell activation in the brain. In contrast, genetic deletion of IL-6 normalized STAT levels and suppressed glial cell activation. These findings indicate that constitutive cytokine secretion leads to activation of STATs and that this secretion is partly caused by an endosomal accumulation of TLR4. These results also suggest that similar signaling events may underlie glial cell activation in the NPC brain