Linked Life Data

9447235

Source:http://linkedlifedata.com/resource/pubmed/id/9447235

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-2-11
pubmed:abstractText
To test the hypothesis that mitochondrial DNA (mtDNA) is more prone to reactive oxygen species (ROS) damage than nuclear DNA, a continuous flux of hydrogen peroxide (H2O2) was produced with the glucose/glucose oxidase system. Using a horse radish peroxidase (HRPO)-based colorimetric assay to detect H2O2, glucose oxidase (GO; 12 mU/ml) produced 95 microM of H2O2 in 1 h, whereas only 46 microM of hydrogen peroxide accumulated in the presence of SV40-transformed human fibroblasts ( approximately 1 x 10(6). DNA damage was assessed in the mitochondira and three nuclear regions using a quantitative PCR assay. GO (12 mU/ml) resulted in more damage to the mitochondrial DNA (2.250 +/- 0.045 lesions/10 kb) than in any one of three nuclear targets, which included the non-expressed beta-globin locus (0.436 +/- 0.029 lesions/10 kb); and the active DNA polymerase b gene (0.442 +/- 0.037 lesions/10 kb); and the active hprt gene (0.310 +/- 0.025). Damage to the mtDNA occurred within 15 min of GO treatment, whereas nuclear damage did not appear until after 30 min, and reached a maximum after 60 min. Repair of mitochondrial damage after a 15 min GO (6 mU/ml) treatment was examined. Mitochondria repaired 50% of the damage after 1 h, and by 6 h all the damage was repaired. Higher doses of GO-generated H202, or more extended treatment periods, lead to mitochondrial DNA damage which was not repaired. Mitochondrial function was monitored using the MTT (3,(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) assay. A 15 min treatment with 6 mU/ml of GO decreased mitochondrial activity to 80% of the control; the activity recovered completely within 1 h after damage. These data show that GO-generated H202 causes acute damage to mtDNA and function, and demonstrate that this organelle is an important site for the cellular toxicity of ROS.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0027-5107
pubmed:author
pubmed:issnType
Print
pubmed:volume
385
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
139-49
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Preferential mitochondrial DNA injury caused by glucose oxidase as a steady generator of hydrogen peroxide in human fibroblasts.
pubmed:affiliation
Sealy Center for Molecular Science, University of Texas Medical Branch, Galveston 77555, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't