Oxidative stress and DNA damage induced by cadmium in the human keratinocyte HaCaT cell line: role of glutathione in the resistance to cadmium.
Cadmium affects the cellular homeostasis and generates damage via complex mechanisms involving interactions with other metals and oxidative stress induction. In this work we used a human keratinocyte cell line (HaCaT) as a model to study the oxidative damage induced by cadmium to cellular macromolecules, its effect on the antioxidant systems and the role of glutathione in cell protection toward cadmium toxicity. The cells were incubated for 24 and 48 h with cadmium (3, 15, 50 and 100 microM). High doses of cadmium were required to induce a cytotoxicity: 100 microM lead to 30% mortality after 24h and 50% after 48 h. The oxidation of lipids and proteins and the DNA damage, respectively, assessed by thiobarbituric acid reactants determination, thiol group measurement and comet assay, were observed for 50-100 microM cadmium. The cytotoxic effects were strongly correlated to the cellular cadmium content. The glutathione peroxidase and the catalase activities were decreased, while the glutathione reductase activity and the glutathione concentration were increased after cadmium treatment. The superoxide dismutases activities were unchanged. A depletion in glutathione prior to cadmium exposure increased the cytotoxic effects and provoked DNA damage. Our results suggested that the hydroxyl radical could be the major compound involved in the oxidative stress generated by cadmium and that glutathione could play a major role in the protection of HaCaT cells from cytotoxicity but mostly from DNA damage induced by cadmium.
Laboratoire Oligoéléments et Résistance au Stress Oxydant induit par les Xénobiotiques, EA-3776, LRC CEA 8M, UFR de Pharmacie, Université Joseph Fourier, Domaine de La Merci, 38700 La Tronche, France.
Yves
Y
Nzengue
Régine
R
Steiman
Catherine
C
Garrel
Emmanuel
E
Lefèbvre
Pascale
P
Guiraud
D000111:Acetylcysteine / Q000494:pharmacology; D000975:Antioxidants / Q000378:metabolism; D019256:Cadmium Chloride / Q000633:toxicity*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage; D005978:Glutathione / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D009153:Mutagens / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects* / Q000235:genetics
D000975:Antioxidants; D009153:Mutagens; D005978:Glutathione; D019256:Cadmium Chloride; D000111:Acetylcysteine