TY - JOUR
T1 - DNA damage, gadd153 expression, and cytotoxicity in plateau-phase renal proximal tubular epithelial cells treated with a quinol thioether
AU - Jeong, Jeongmi K.
AU - Dybing, Erik
AU - Søderlund, Erik
AU - Brunborg, Gunnar
AU - Holme, Jörn A.
AU - Lau, Serrine S.
AU - Monks, Terrence J.
N1 - Funding Information:
1This work was made possible by Grant ES 07359 (T.J.M.) from the National Institute of Environmental Health Science. 2 Present address: Division of Toxicology, M.I.T., 77 Massachusetts Ave., 56-638, Cambridge, MA 02139-4307. 3To whom correspondence should be addressed. Fax: (512) 471-5002. E-mail: [email protected].
PY - 1997/5/15
Y1 - 1997/5/15
N2 - 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.
AB - 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.
KW - DNA damage
KW - gadd153
KW - growth arrest
KW - hydrogen peroxide
KW - quinone thioethers
KW - reactive oxygen species
KW - stress response
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U2 - 10.1006/abbi.1997.9969
DO - 10.1006/abbi.1997.9969
M3 - Article
C2 - 9169019
AN - SCOPUS:17944404402
SN - 0003-9861
VL - 341
SP - 300
EP - 308
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 2
ER -