title: Divergent role of calcium on Abeta- and MPTP-induced cell death in SK-N-SH neuroblastoma.
abstract: We attempted to clarify the role of Ca2+ in cell death caused by beta-amyloid protein (Abeta) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in SK-N-SH neuroblastoma, respectively. Two insults both reduced cell viability in a concentration-dependent manner and induced equal cytotoxicity in the presence of 20 microM Abeta and 0.4 mM MPTP for 72 h, respectively (68+/-7 vs. 64+/-6% viability). Time-related study showed that Abeta evoked cell death occurred quickly at 24 h. Relatively, MPTP exhibited a delayed cell death significantly after 72 h of culture. Pretreating the cells with nimodipine and chelating of Ca2+ by EGTA plus 1,2-bis-(O-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM) successfully rescued Abeta-induced cell death but failed to prevent MPTP toxicity. ELISA determination of mono/oligonucleosomes accumulation showed the mode of cell death evoked by MPTP was presumably apoptosis while by Abeta was necrosis. SK-N-SH cells constitutively expressed the alpha(1C) subunit of L-type Ca2+ channel and exposure to Abeta or MPTP for 96 h did not further modify its expression. By contrast, alpha(1D) subunit was undetectable or low level expressed in basal condition, but was induced to express after Abeta and MPTP stimulation in a time-dependent manner. Functional assay revealed that KCl-evoked [Ca2+]i rise was significantly greater in Abeta-, but not in MPTP-treated cells when compared with control. Taken together, these results showed that Abeta and MPTP elicited different mode of cell death in SK-N-SH. Nevertheless, Ca2+ overload seems to solely display a crucial role in Abeta-induced cytotoxicity and over-expressed alpha(1D) may contribute to the disruption of cellular Ca2+ homeostasis.
authors.affiliation: Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan, ROC.
authors.forename: Wan-Shin
authors.initials: WS
authors.lastname: Lee
authors.forename: Wei-Jen
authors.initials: WJ
authors.lastname: Tsai
authors.forename: Pen-Ho
authors.initials: PH
authors.lastname: Yeh
authors.forename: Bai-Luh
authors.initials: BL
authors.lastname: Wei
authors.forename: Wen-Fei
authors.initials: WF
authors.lastname: Chiou
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology*; D016229:Amyloid beta-Peptides / Q000378:metabolism / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D009447:Neuroblastoma / Q000473:pathology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C074636:amyloid beta-protein (25-35); D011189:Potassium Chloride; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D002118:Calcium