Oxidative stress-induced DNA damage and cell cycle regulation in B65 dopaminergic cell line.
Reactive oxygen species and oxidative stress are associated with neuronal cell death in many neurodegenerative conditions. However, the exact molecular mechanisms triggered by oxidative stress in neurodegeneration are still unclear. This study used the B65 rat neuroblastoma cell line as a model to study the molecular events that occur after H(2)O(2) treatment. Treatment of B65 cells with H(2)O(2) rapidly up-regulated the DNA damage pathway involved in double-strand breakage. Subsequently, proteins involved in p53 regulation, such as sirtuin 1 and STAT1, were modified. In addition, H(2)O(2) treatment altered the pattern of cell cycle protein expression. Specifically, a decrease was found in the expression of cyclin D1, cdk4 and surprisingly the levels of cyclin A and the retinoblastoma protein phosphorylated at ser780 were increased. Furthermore, this study shows that pre-treatment of B65 cells with 50 microM trolox confers almost total protection against apoptotic cell death and restores the cell cycle. Likewise, the increase in retinoblastoma phosphorylation was attenuated by KU-55993, a selective ATM inhibitor, and also by trolox. These observations indicate that DNA damage and oxidative stress are responsible for cell cycle regulation. In summary, this study describes the molecular mechanisms involved in cell cycle alterations induced by oxidative stress in B65 cells. These findings highlight the relevance of ATM in the regulation of cell cycle after oxidative stress.
Pizarro
Javier G
JG
Unitat de Farmacologia i Farmacognosia, Institut de Biomedicina, Centro de Investigacion Biomedica en Red de Enfermedades Neurodegenerativas, Facultat de Farmacia, Universitat de Barcelona, Nucli Universitari de Pedralbes, Barcelona, Spain.
Folch
Jaume
J
Vazquez De la Torre
Aurelio
A
Verdaguer
Ester
E
Junyent
Felix
F
Jordán
Joaquín
J
Pallàs
Mercè
M
Camins
Antoni
A
D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D005434:Flow Cytometry; D006861:Hydrogen Peroxide / Q000494:pharmacology; D009447:Neuroblastoma; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D018384:Oxidative Stress / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D006861:Hydrogen Peroxide; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases