Document Detail


Arsenite and monomethylarsonous acid generate oxidative stress response in human bladder cell culture.
MedLine Citation:
PMID:  16930658     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Arsenicals have commonly been seen to induce reactive oxygen species (ROS) which can lead to DNA damage and oxidative stress. At low levels, arsenicals still induce the formation of ROS, leading to DNA damage and protein alterations. UROtsa cells, an immortalized human urothelial cell line, were used to study the effects of arsenicals on the human bladder, a site of arsenical bioconcentration and carcinogenesis. Biotransformation of As(III) by UROtsa cells has been shown to produce methylated species, namely monomethylarsonous acid [MMA(III)], which has been shown to be 20 times more cytotoxic. Confocal fluorescence images of UROtsa cells treated with arsenicals and the ROS sensing probe, DCFDA, showed an increase of intracellular ROS within five min after 1 microM and 10 microM As(III) treatments. In contrast, 50 and 500 nM MMA(III) required pretreatment for 30 min before inducing ROS. The increase in ROS was ameliorated by preincubation with either SOD or catalase. An interesting aspect of these ROS detection studies is the noticeable difference between concentrations of As(III) and MMA(III) used, further supporting the increased cytotoxicity of MMA(III), as well as the increased amount of time required for MMA(III) to cause oxidative stress. These arsenical-induced ROS produced oxidative DNA damage as evidenced by an increase in 8-hydroxyl-2'-deoxyguanosine (8-oxo-dG) with either 50 nM or 5 microM MMA(III) exposure. These findings provide support that MMA(III) cause a genotoxic response upon generation of ROS. Both As(III) and MMA(III) were also able to induce Hsp70 and MT protein levels above control, showing that the cells recognize the ROS and respond. As(III) rapidly induces the formation of ROS, possibly through it oxidation to As(V) and further metabolism to MMA(III)/(V). These studies provide evidence for a different mechanism of MMA(III) toxicity, one that MMA(III) first interacts with cellular components before an ROS response is generated, taking longer to produce the effect, but with more substantial harm to the cell.
Authors:
K E Eblin; M E Bowen; D W Cromey; T G Bredfeldt; E A Mash; S S Lau; A J Gandolfi
Related Documents :
1662318 - Reactive oxygen species and rat renal epithelial cells during hypoxia and reoxygenation.
17360118 - Hydrogen peroxide mediates damage by xanthine and xanthine oxidase in cerebellar granul...
1544838 - Evaluation of bioreductive drugs in multicell spheroids.
6188608 - Dynamics of the neuroendocrine cell--regulatory peptide system in the lung. specific ov...
15093738 - Attempted endocytosis of nano-environment produced by colloidal lithography by human fi...
14642818 - Inhibition of human colon carcinoma cell growth by ammonia: a non-cytotoxic process ass...
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2006-07-21
Journal Detail:
Title:  Toxicology and applied pharmacology     Volume:  217     ISSN:  0041-008X     ISO Abbreviation:  Toxicol. Appl. Pharmacol.     Publication Date:  2006 Nov 
Date Detail:
Created Date:  2006-10-31     Completed Date:  2006-12-07     Revised Date:  2007-12-03    
Medline Journal Info:
Nlm Unique ID:  0416575     Medline TA:  Toxicol Appl Pharmacol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  7-14     Citation Subset:  IM    
Affiliation:
Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, 1703 E. Mabel, PO Box 210207, Tucson, AZ 85721, USA. eblin@pharmacy.arizona.edu <eblin@pharmacy.arizona.edu>
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Arsenites / toxicity*
Biotransformation
Carcinogens, Environmental / metabolism,  toxicity*
Catalase / metabolism
Cell Line
DNA / drug effects,  metabolism
DNA Damage
Deoxyguanosine / analogs & derivatives,  analysis
Dose-Response Relationship, Drug
HSP70 Heat-Shock Proteins / biosynthesis
Humans
Metallothionein / biosynthesis
Organometallic Compounds / metabolism,  toxicity*
Oxidative Stress / drug effects*
Reactive Oxygen Species / metabolism
Superoxide Dismutase / metabolism
Time Factors
Up-Regulation / drug effects
Urinary Bladder / drug effects*,  metabolism
Urothelium / drug effects,  metabolism
Grant Support
ID/Acronym/Agency:
ES 06694/ES/NIEHS NIH HHS; ES 07091/ES/NIEHS NIH HHS; ES-04940/ES/NIEHS NIH HHS
Chemical
Reg. No./Substance:
0/8-hydroxy-2'-deoxyguanosine; 0/Arsenites; 0/Carcinogens, Environmental; 0/HSP70 Heat-Shock Proteins; 0/Organometallic Compounds; 0/Reactive Oxygen Species; 0/monomethylarsonous acid; 15502-74-6/arsenite; 9007-49-2/DNA; 9038-94-2/Metallothionein; 961-07-9/Deoxyguanosine; EC 1.11.1.6/Catalase; EC 1.15.1.1/Superoxide Dismutase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Glutathione-S-transferase-omega [MMA(V) reductase] knockout mice: enzyme and arsenic species concent...
Next Document:  Experimental immunization with Thalassophryne nattereri fish venom: striking IL-5 production and imp...