Possible involvement of 12-lipoxygenase activation in glucose-deprivation/reload-treated neurons.
The aim of this study was to clarify whether 12-lipoxygenase (12-LOX) activation was involved in reactive oxygen species (ROS) generation, extensive poly(ADP-ribose) polymerase (PARP) activation and neuronal death induced by glucose-deprivation, followed by glucose-reload (GD/R). The decrease of neuronal viability and accumulation of poly(ADP-ribose) induced by GD/R were prevented 3-aminobenzamide, a representative PARP inhibitor, demonstrating this treatment protocol caused the same oxidative stress with the previously reported one. The PARP activation, ROS generation and decrease of neuron viability induced by GD/R treatment were almost completely abolished by an extracellular zinc chelator, CaEDTA. p47(phox), a cytosolic component of NADPH oxidase was translocated the membrane fraction by GD/R, indicating its activation, but it did not generate detectable ROS. Surprisingly, pharmacological inhibition of NADPH oxidase with apocynin and AEBSF further decreased the decreased neuron viability induced by GD/R. On the other hand, AA861, a 12-LOX inhibitor, prevented ROS generation and decrease of neuron viability caused by GD/R. Interestingly, an antioxidant, N-acetyl-l-cysteine rescued the neurons from GD/R-induced oxidative stress, implying effectiveness of antioxidant administration. These findings suggested that activation of 12-LOX, but not NADPH oxidase, following to zinc release might play an important role in ROS generation and decrease of viability in GD/R-treated neurons.
Nagasawa
Kazuki
K
Department of Environmental Biochemistry, Kyoto Pharmaceutical University, Misasagi, Kyoto 607-8414, Japan. nagasawa@mb.kyoto-phu.ac.jp
Kakuda
Taichi
T
Higashi
Youichirou
Y
Fujimoto
Sadaki
S
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001092:Arachidonate 12-Lipoxygenase / Q000378:metabolism*; D001921:Brain / Q000201:enzymology* / Q000503:physiopathology; D002545:Brain Ischemia / Q000201:enzymology* / Q000503:physiopathology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005947:Glucose / Q000172:deficiency*; D007003:Hypoglycemia / Q000201:enzymology* / Q000503:physiopathology; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D015032:Zinc / Q000172:deficiency
D000975:Antioxidants; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D001092:Arachidonate 12-Lipoxygenase; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; C499322:Parp1 protein, rat; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D005947:Glucose; D015032:Zinc