DNA damage, gadd153 expression, and cytotoxicity in plateau-phase renal proximal tubular epithelial cells treated with a quinol thioether

Jeongmi K. Jeong, Erik Dybing, Erik Søderlund, Gunnar Brunborg, Jörn A. Holme, Serrine S. Lau, Terrence J. Monks

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

2-Bromo-bis-(glutathion-S-yl)hydroquinone [2-Br-bis-(GSyl)HQ] causes DNA single-strand breaks (SSB), causes growth arrest, induces the expression of gadd153 (a gene inducible by growth arrest and DNA damage), and decreases histone H2B mRNA in logphase renal proximal tubular epithelial cells (LLC- PK1). Renal epithelial cells in vivo normally exhibit a low mitotic index, therefore experiments in both plateau- and log-phase cells are necessary for a comprehensive understanding of the stress response to 2-Br-bis-(GSyl)HQ. In the present article we demonstrate that not all features of the stress response in log-phase cells are reproduced in plateau-phase cells. Thus, although 2-Br-bis-(GSyl)HQ causes concentration and time-dependent increases in DNA SSB, and increases the expression of gadd153, histone H2B mRNA levels are unaltered in plateau-phase cells. The relationship between reactive oxygen species, DNA damage, gene expression, and cytotoxicity was also investigated. Our findings suggest that (i) 2-Br-bis-(GSyl)HQ-mediated DNA damage in LLC-PK1 cells is mediated by the generation of H2O2; (ii) DNA damage, either directly or indirectly, contributes to cell death; and (iii) DNA damage, either directly or indirectly, provides the initial signal for gadd153 expression. In addition, DNA repair is rapid in LLC-PK1 cells, and the DNA-repair inhibitors 1-β-D-arabinofuranosylcytosine and hydroxyurea have no effect on the amount of DNA SSB. Although the addition of 3- aminobenzamide following 2-Br-bis-(GSyl)HQ exposure has no effect on the removal of DNA SSB, it causes a slight but significant increase in gadd153 expression and cell viability, indicating that activation of poly(ADP- ribose)polymerase may exacerbate toxicity. Finally, aurintricarboxylic acid did not prevent DNA SSB or cytotoxicity in 2-Br-bis-(GSyl) HQ-treated LLC- PK1 cells, implying that activation of endonucleases does not play a role in these processes.

Original languageEnglish (US)
Pages (from-to)300-308
Number of pages9
JournalArchives of Biochemistry and Biophysics
Volume341
Issue number2
DOIs
StatePublished - May 15 1997

Keywords

  • DNA damage
  • gadd153
  • growth arrest
  • hydrogen peroxide
  • quinone thioethers
  • reactive oxygen species
  • stress response

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology

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