Cheung Nam Sang, Koh Chor Hui Vivien, Bay Boon Huat, Qi Robert Z, Choy Meng Shyan, Li Qiu-Tian, Wong Kim Ping, Whiteman Matthew
Department of Biochemistry, Faculty of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore.
Biochem Biophys Res Commun. 2004 Mar 5;315(2):408-17. doi: 10.1016/j.bbrc.2004.01.066.
Niemann-Pick disease type C (NPC) is a juvenile neurodegenerative disorder characterized by premature neuronal loss and altered cholesterol metabolism. Previous reports applying an 8-h exposure of U18666A, a cholesterol transport-inhibiting agent, demonstrated a dose-dependent reduction in beta-amyloid (Abeta) deposition and secretion in cortical neurons, with no significant cell injury. In the current study, we examined the chronic effect of 24-72h of U18666A treatment on primary cortical neurons and several cell lines. Our results showed caspase-3 activation and cellular injury in U18666A-treated cortical neurons but not in the cell lines, suggesting cell death by apoptosis only occurred in cortical neurons after chronic exposure to U18666A. We also demonstrated through filipin staining the accumulation of intracellular cholesterol in cortical neurons treated with U18666A, indicating the phenotypic mimic of NPC by U18666A. However, additions of 10 and 25microM pravastatin with 0.5microg/ml U18666A significantly attenuated toxicity. Taken together, these data showed for the first time that U18666A induces cell death by apoptosis and suggested an important in vitro model system to study NPC.
尼曼-匹克C型病（NPC）是一种青少年神经退行性疾病，其特征为神经元过早丧失和胆固醇代谢改变。先前的报告显示，应用胆固醇转运抑制剂U18666A进行8小时的暴露，可使皮质神经元中β-淀粉样蛋白（Aβ）的沉积和分泌呈剂量依赖性减少，且无明显细胞损伤。在本研究中，我们检测了U18666A处理24至72小时对原代皮质神经元和几种细胞系的慢性影响。我们的结果显示，U18666A处理的皮质神经元中caspase-3激活和细胞损伤，但细胞系中未出现，这表明慢性暴露于U18666A后，仅在皮质神经元中发生凋亡导致的细胞死亡。我们还通过 Filipin染色证明，U18666A处理的皮质神经元中存在细胞内胆固醇积累，表明U18666A可模拟NPC的表型。然而，添加10和二十五微摩尔普伐他汀与0.5微克/毫升U18666A可显著减轻毒性。综上所述，这些数据首次表明U18666A可诱导凋亡导致细胞死亡，并提示了一个研究NPC的重要体外模型系统。
