title: 2,5-hexanedione induced apoptosis of rat bone marrow mesenchymal stem cells by reactive oxygen species.
abstract: OBJECTIVE
  n-Hexane, a common industrial organic solvent, causes multiple organ damage, especially neurotoxicity, which is proved to be caused by its metabolite 2,5-hexanedione (2,5-HD). We previously showed that 2,5-HD induced apoptosis of rat bone marrow mesenchymal stem cells (BMSCs). In the current study, we explored the mechanism of 2,5-HD-induced apoptosis, especially the role played by reactive oxygen species (ROS).
  
  
  METHODS
  Intracellular ROS levels after 2,5-HD treatment were measured by the dichloro-dihydro-fluorescein diacetate (DCFH-DA) method, and the antioxidant N-acetyl cysteine (NAC) was used to scavenge ROS. Apoptosis, mitochondrial membrane potential (MMP), and caspase-3 activity were measured after 2,5-HD exposure with or without NAC pretreatment.
  
  
  RESULTS
  In rat BMSCs, 20 mM 2,5-HD significantly increased ROS levels and apoptosis. In addition, MMP activity was decreased and caspase-3 activity was increased. With NAC pretreatment, ROS increases were prevented, cells were rescued from apoptosis, and both MMP and caspase-3 activity returned to normal levels. Western blotting analysis of malondialdehyde-modified proteins and superoxide dismutase (SOD) 1 showed that after 2,5-HD exposure, BMSCs had oxidative damage and abnormal SOD1 expression. These returned to normal when cells were pretreated with NAC in addition to 20 mM 2,5-HD. Furthermore, the expressions of NF-κB p65/RelA and phospho-NF-κB p65/RelA (Ser536) were suppressed after 2,5-HD exposure and restored by NAC pretreatment.
  
  
  CONCLUSIONS
  2,5-HD-induced apoptosis in rat BMSCs is potentially mediated by excessive ROS production.
authors.affiliation: Department of Occupational and Environmental Health, Dalian Medical University.
authors.forename: Shuang
authors.initials: S
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Longjuan
authors.initials: L
authors.lastname: Wang
authors.forename: Wenchang
authors.initials: W
authors.lastname: Sun
authors.forename: Qigui
authors.initials: Q
authors.lastname: Liu
authors.forename: Haibo
authors.initials: H
authors.lastname: Chen
authors.forename: Dan
authors.initials: D
authors.lastname: Su
authors.forename: Yue
authors.initials: Y
authors.lastname: Jiang
authors.forename: Fengyuan
authors.initials: F
authors.lastname: Piao
authors.forename: Xiance
authors.initials: X
authors.lastname: Sun
authors.forename: Wenfang
authors.initials: W
authors.lastname: Sun
mesh_terms: D000111:Acetylcysteine; D000818:Animals; D000975:Antioxidants; D017209:Apoptosis / Q000187:drug effects*; D001854:Bone Marrow Cells / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D006588:Hexanones / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D059630:Mesenchymal Stem Cells / Q000187:drug effects*; D051336:Mitochondrial Membranes / Q000187:drug effects; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D006588:Hexanones; D017382:Reactive Oxygen Species; C011269:2,5-hexanedione; D013482:Superoxide Dismutase; D053148:Caspase 3; D000111:Acetylcysteine