title: Overexpression of manganese-superoxide dismutase prevents methylmercury toxicity in HeLa cells.
abstract: HeLa cells were stably transformed with plasmid constructs that allowed constitutive expression of antioxidant enzymes such as catalase, glutathione peroxidase (GSH-Px), Cu,Zn-superoxide dismutase (Cu,Zn-SOD) or Mn-superoxide dismutase (Mn-SOD) to examine the involvement of reactive oxygen generation in methylmercury toxicity. Overexpression of catalase, GSH-Px or Cu,Zn-SOD did not affect the sensitivity of HeLa cells against methylmercury. However, the sensitivity of HeLa cells against methylmercury was decreased by overexpression of Mn-SOD, an enzyme localized in matrix of mitochondria and which decomposes superoxide anions. These results suggest that formation of superoxide anions in the mitochondria might be involved in the mechanism of the cytotoxicity of methylmercury.
authors.affiliation: Department of Public Health and Molecular Toxicology, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan. naganuma@mail.cc.tohoku.ac.jp
authors.forename: A
authors.initials: A
authors.lastname: Naganuma
authors.forename: K
authors.initials: K
authors.lastname: Miura
authors.forename: T
authors.initials: T
authors.lastname: Tanaka-Kagawa
authors.forename: J
authors.initials: J
authors.lastname: Kitahara
authors.forename: Y
authors.initials: Y
authors.lastname: Seko
authors.forename: H
authors.initials: H
authors.lastname: Toyoda
authors.forename: N
authors.initials: N
authors.lastname: Imura
mesh_terms: D002374:Catalase / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008767:Methylmercury Compounds / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012680:Sensitivity and Specificity; D013482:Superoxide Dismutase / Q000096:biosynthesis / Q000378:metabolism*; D014162:Transfection
chemical_list: D018076:DNA, Complementary; D008767:Methylmercury Compounds; D017382:Reactive Oxygen Species; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase