title: Iron overload induced by ferric ammonium citrate triggers reactive oxygen species-mediated apoptosis via both extrinsic and intrinsic pathways in human hepatic cells.
abstract: BACKGROUND
  Hepatic iron overload is common in patients with myelodysplastic syndromes undergoing hematopoietic cell transplantation (HCT) and may predispose to peri- and post-HCT toxicity. To better understand the mechanisms of iron overload-induced liver injury, we examined the effects of iron overload induced by ferric ammonium citrate (FAC) on oxidative stress and apoptosis signaling pathway in human hepatic cell line HH4.
  
  
  RESULTS
  Hepatic HH4 cells were exposed to FAC to force iron uptake, and cellular responses were determined. Incubation with 5 mM FAC resulted in increased intracellular iron content in a time-dependent manner. High concentration of FAC impaired cell viability and increased level of reactive oxygen species (ROS), and addition of antioxidant reagent such as glutathione or N-acetylcysteine dramatically reduced FAC-induced intracellular ROS generation. FAC overload significantly increased the phosphorylation of inhibitor of κB-α, p38 mitogen-activated protein kinase (MAPK), and nuclear factor κ light chain enhancer of activated B cells (NF-κB) p65 and promoted the nuclear translocation of NF-κB p65. Knockdown of Fas and Bid expression by small interfering RNA in iron-treated HH4 cells resulted in restoration of cell viability.
  
  
  CONCLUSIONS
  We reported that FAC treatment is capable of inducing both extrinsic death receptor and intrinsic mitochondrial signaling pathway-mediated HH4 cells apoptosis through ROS-activated p38 MAPK and NF-κB pathways.
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, Jiangsu, China School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China.
authors.forename: S-W
authors.initials: SW
authors.lastname: Li
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, Jiangsu, China School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China.
authors.forename: C-M
authors.initials: CM
authors.lastname: Liu
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, Jiangsu, China School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China.
authors.forename: J
authors.initials: J
authors.lastname: Guo
authors.affiliation: Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Marcondes
authors.affiliation: Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA Department of Medicine, University of Washington, Seattle, WA, USA.
authors.forename: J
authors.initials: J
authors.lastname: Deeg
authors.affiliation: Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu, China xiangli@jiangnan.edu.cn.
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, Jiangsu, China School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China fengguan@jiangnan.edu.cn.
authors.forename: F
authors.initials: F
authors.lastname: Guan
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000276:immunology; D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D005290:Ferric Compounds / Q000633:toxicity*; D022781:Hepatocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007501:Iron / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D000644:Quaternary Ammonium Compounds / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D005290:Ferric Compounds; D016328:NF-kappa B; D000644:Quaternary Ammonium Compounds; D017382:Reactive Oxygen Species; D007501:Iron; D048051:p38 Mitogen-Activated Protein Kinases; C013531:ferric ammonium citrate
keywords: Iron overload; NF-κB; antioxidant; apoptosis; p38 MAPK; reactive oxygen species