Carcinogenesis, Vol. 20, No. 2, 333-337,
February 1999
© 1999 Oxford University Press
Influence of glutathione levels and heat-shock on the steady-state levels of oxidative DNA base modifications in mammalian cells
Institute of Pharmacy, University of Mainz, Staudinger Weg 5, D-55099 Mainz, Germany and
1 Centre of Molecular and Cellular Genetics, CNRS-UMR-106, Claude Bernard University Lyon, 69622 Villeurbanne, France
The effects of thiols, ascorbic acid and thermal stress on the basal (steady-state) levels of oxidative DNA base modifications were studied. In various types of untreated cultured mammalian cells, the levels of total glutathione were found to be inversely correlated with the levels of DNA base modifications sensitive to the repair endonuclease Fpg protein, which include 8-hydroxyguanine (8-oxoG). A depletion of glutathione by treatment with buthionine sulphoximine increased the steady-state level in AS52 Chinese hamster cells by ~50%. However, additional thiols in the culture medium did not reduce the level of Fpg-sensitive base modifications: 0–10 mM N-acetylcysteine had no effect, whereas cysteine ethylester even increased the oxidative DNA damage at concentrations >0.1 mM. Similarly, ascorbic acid (0–20 mM) failed to reduce the steady-state levels. When AS52 cells were grown at elevated temperature (41°C), the steady-state level of the oxidative DNA modifications increased by 40%, in spite of a concomitant 1.6-fold increase of the cellular level of total glutathione. Depletion of glutathione at 41°C nearly doubled the already elevated level of oxidative damage. A constitutive expression of the heat-shock protein Hsp27 in L929 mouse fibrosarcoma cells at 37°C increased the glutathione level by 60%, but had little effect on the level of oxidative DNA damage.
Abbreviations: BSO, buthionine[S,R]sulphoximine; CYSET, cysteine ethylester; DTNB, 5,5'-dithio-(2-nitrobenzoic acid); GSH, glutathione (reduced form); GSSG, glutathione (oxidized form); NAC, N-acetylcysteine; 8-oxoG, 8-hydroxyguanine; ROS, reactive oxygen species; s.s.b., single-strand breaks; TNF
, tumour necrosis factor .
2 To whom correspondence should be addressed Email: epe{at}mail.uni-mainz.de
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  S. Salinthone, M. Ba, L. Hanson, J. L. Martin, A. J. Halayko, and W. T. Gerthoffer Overexpression of human Hsp27 inhibits serum-induced proliferation in airway smooth muscle myocytes and confers resistance to hydrogen peroxide cytotoxicity Am J Physiol Lung Cell Mol Physiol, November 1, 2007; 293(5): L1194 - L1207. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. T. Selsby, S. Rother, S. Tsuda, O. Pracash, J. Quindry, and S. L. Dodd Intermittent hyperthermia enhances skeletal muscle regrowth and attenuates oxidative damage following reloading J Appl Physiol, April 1, 2007; 102(4): 1702 - 1707. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. M.Green, M. Graham, M. R.O'Donovan, J.K. Chipman, and N. J.Hodges Subcellular compartmentalization of glutathione: Correlations with parameters of oxidative stress related to genotoxicity Mutagenesis, November 1, 2006; 21(6): 383 - 390. [Abstract] [Full Text] [PDF]
|
|