title: Chronic exposure to U18666A induces apoptosis in cultured murine cortical neurons.
abstract: 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.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore. bchcns@nus.edu.sg
authors.forename: Nam Sang
authors.initials: NS
authors.lastname: Cheung
authors.forename: Chor Hui Vivien
authors.initials: CH
authors.lastname: Koh
authors.forename: Boon Huat
authors.initials: BH
authors.lastname: Bay
authors.forename: Robert Z
authors.initials: RZ
authors.lastname: Qi
authors.forename: Meng Shyan
authors.initials: MS
authors.lastname: Choy
authors.forename: Qiu-Tian
authors.initials: QT
authors.lastname: Li
authors.forename: Kim Ping
authors.initials: KP
authors.lastname: Wong
authors.forename: Matthew
authors.initials: M
authors.lastname: Whiteman
mesh_terms: D000736:Androstenes / Q000494:pharmacology*; D000818:Animals; D000924:Anticholesteremic Agents / Q000494:pharmacology; D017209:Apoptosis; D015153:Blotting, Western; D016466:CHO Cells; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects*; D002784:Cholesterol / Q000378:metabolism; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005372:Filipin / Q000378:metabolism; D006801:Humans; D051379:Mice; D008854:Microscopy, Electron; D041681:NIH 3T3 Cells; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D017035:Pravastatin / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000736:Androstenes; D000924:Anticholesteremic Agents; D004791:Enzyme Inhibitors; C006261:3-beta-(2-(diethylamino)ethoxy)androst-5-en-17-one; D005372:Filipin; D002784:Cholesterol; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; D017035:Pravastatin