title: Ionomycin-induced calcium influx induces neurite degeneration in mouse neuroblastoma cells: analysis of a time-lapse live cell imaging system.
abstract: Reactive oxygen species induce neuronal cell death. However, the detailed mechanisms of cell death have not yet been elucidated. Previously, we reported neurite degeneration before the induction of cell death. Here, we attempted to elucidate the mechanisms of neurite degeneration before the induction of cell death using the neuroblastoma N1E-115 cell line and a time-lapse live cell imaging system. Treatment with the calcium ionophore ionomycin induced cell death and neurite degeneration in a concentration- and time-dependent manner. Treatment with a low concentration of ionomycin immediately produced a significant calcium influx into the intracellular region in N1E-115 cells. After 1-h incubation with ionomycin, the fluorescence emission of MitoSOXTMincreased significantly compared to the control. Finally, analysis using a new mitochondrial specific fluorescence dye, MitoPeDPP, indicated that treatment with ionomycin significantly increased the mitochondrial lipid hydroperoxide production in N1E-115 cells. The fluorescence emissions of Fluo-4 AM and MitoPeDPP were detected in the cell soma and neurite regions in ionomycin-treated N1E-115 cells. However, the emissions of neurites were much lower than those of the cell soma. TBARS values of ionomycin-treated cells significantly increased compared to the control. These results indicate that ionomycin induces calcium influx into the intracellular region and reactive oxygen species production in N1E-115 cells. Lipid hydroperoxide production was induced in ionomycin-treated N1E-115 cells. Calcium influx into the intracellular region is a possible activator of neurite degeneration.
authors: a Molecular Cell Biology Laboratory, Systems Engineering and Science , Graduate School of Engineering and Science, Shibaura Institute of Technology , Saitama , Japan.
authors: Saki
authors: S
authors: Nakamura
authors: b Molecular Cell Biology Laboratory, Department of Bioscience and Engineering , College of Systems Engineering and Sciences, Shibaura Institute of Technology , Saitama , Japan.
authors: Ayumi
authors: A
authors: Nakanishi
authors: b Molecular Cell Biology Laboratory, Department of Bioscience and Engineering , College of Systems Engineering and Sciences, Shibaura Institute of Technology , Saitama , Japan.
authors: Minami
authors: M
authors: Takazawa
authors: a Molecular Cell Biology Laboratory, Systems Engineering and Science , Graduate School of Engineering and Science, Shibaura Institute of Technology , Saitama , Japan.
authors: Shunsuke
authors: S
authors: Okihiro
authors: b Molecular Cell Biology Laboratory, Department of Bioscience and Engineering , College of Systems Engineering and Sciences, Shibaura Institute of Technology , Saitama , Japan.
authors: Shiro
authors: S
authors: Urano
authors: a Molecular Cell Biology Laboratory, Systems Engineering and Science , Graduate School of Engineering and Science, Shibaura Institute of Technology , Saitama , Japan.|b Molecular Cell Biology Laboratory, Department of Bioscience and Engineering , College of Systems Engineering and Sciences, Shibaura Institute of Technology , Saitama , Japan.
authors: Koji
authors: K
authors: Fukui
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D016923:Cell Death; D015759:Ionomycin / Q000378:metabolism*; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D016501:Neurites / Q000502:physiology; D009447:Neuroblastoma / Q000378:metabolism*; D018384:Oxidative Stress; D017382:Reactive Oxygen Species
chemical_list: D017382:Reactive Oxygen Species; D015759:Ionomycin; D002118:Calcium
keywords: Neurite; calcium; oxidative stress