title: Characterization of free radical defense system in high glucose cultured HeLa-tat cells: consequences for glucose-induced cytotoxicity.
abstract: HeLa cell line stably transfected with the tat gene from human immunodeficiency virus type 1 has a decreased antioxidant potential. In this work, we used this model to investigate the effect of a high glucose level (20 mM) on the glucose induced cytotoxicity and on the antioxidant system. In comparison to cell culture under control medium, HeLa-wild cell cultured under 20 mM glucose did not exhibit necrosis or apoptosis, contrary to HeLa-tat cell presenting a significant increase in necrotic or apoptotic state. Moreover after 48 h culture under high glucose level the HeLa-tat proliferation rate was not higher than the one of HeLa-wild cells. In HeLa-wild cell high glucose level resulted in an induction of glutathione reductase activity in opposition to HeLa-tat cells where no change was observed. High glucose level resulted in 20% increase in GSSG/GSH ratio in HeLa-wild cells and 38% increase in HeLa-tat cells. Moreover, high glucose level resulted in a dramatic cytosolic thiol decrease and an important lipid peroxidation in HeLa-tat cells. No significant change of these two parameters was observed in HeLa-wild cells. In both cell lines, high glucose resulted in an increase of total SOD activity, as a consequence of the increase in Cu,Zn-SOD activity. High glucose did not result in an increase of Mn-SOD activity in both cell lines. As a consequence of tat tranfection Mn-SOD activity was 50% lower in HeLa-tat cells in comparison to HeLa-wild cells. This work emphasizes the importance of the antioxidant system in the glucose induced cytotoxicity.
authors.affiliation: Laboratoire de Biochimie, Faculté de Médecine, Université Joseph Fourier, 38000 Grenoble, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Bouvard
authors.forename: Patrice
authors.initials: P
authors.lastname: Faure
authors.forename: Corinne
authors.initials: C
authors.lastname: Roucard
authors.forename: Alain
authors.initials: A
authors.lastname: Favier
authors.forename: Serge
authors.initials: S
authors.lastname: Halimi
mesh_terms: D017209:Apoptosis; D002374:Catalase / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D015696:Gene Products, tat / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D015227:Lipid Peroxidation; D008345:Manganese / Q000378:metabolism; D008353:Mannitol / Q000378:metabolism; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014162:Transfection; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D015696:Gene Products, tat; D017382:Reactive Oxygen Species; D013438:Sulfhydryl Compounds; D017392:Thiobarbituric Acid Reactive Substances; D054322:tat Gene Products, Human Immunodeficiency Virus; D013481:Superoxides; D008353:Mannitol; D008345:Manganese; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione; D005947:Glucose