title: c-Jun N-terminal kinase pathway mediates Lactacystin-induced cell death in a neuronal differentiated Neuro2a cell line.
abstract: The ubiquitin-proteasome pathway is an intracellular protein degradation pathway responsible for degradation of many regulatory proteins that must be rapidly eliminated normally. Some recent studies reported that a proteasome dysfunction was involved in the pathogenesis of neurodegenerative diseases. Thus, there is now considerable interest in the possible role of proteasome in this regard. Here we show that inhibition of proteasomal function by Lactacystin-induced cell death in a neuronal differentiated Neuro2a (nN2a) cell line but not in an undifferentiated Neuro2a (N2a) cell line. Cell death was accompanied by both the activation of c-Jun N-terminal kinase, p38 and caspase-3. A pan-caspase inhibitor, Z-VAD-FMK, or SB203580, a p38 inhibitor could not inhibit cell death induced by Lactacystin, whereas nN2a cell lines with stable expression of the dominant negative mutant of c-Jun N-terminal kinase showed a remarkable suppression of cell death. Lactacystin-induced cell death is mediated through the c-Jun N-terminal kinase pathway but not the caspase-dependent pathway in a nN2a cell line. Our results shed light on the association among the proteasomal dysfunction, JNK pathway and neuronal cell death, leading to the elucidation of its possible role in the pathogenesis of neurodegenerative diseases.
authors.affiliation: Department of Neurology, Nagoya University, Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Aichi, Japan.
authors.forename: Chen
authors.initials: C
authors.lastname: Sang
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Jun
authors.initials: J
authors.lastname: Du
authors.forename: Masahisa
authors.initials: M
authors.lastname: Katsumo
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Adachi
authors.forename: Manabu
authors.initials: M
authors.lastname: Doyu
authors.forename: Gen
authors.initials: G
authors.lastname: Sobue
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D004789:Enzyme Activation; D048031:JNK Mitogen-Activated Protein Kinases; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D014407:Tumor Cells, Cultured; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D009097:Multienzyme Complexes; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C067713:lactacystin; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D000111:Acetylcysteine