Linked Life Data

9586811

Source:http://linkedlifedata.com/resource/pubmed/id/9586811

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1998-7-23
pubmed:abstractText
We have previously shown that fibroblasts from ultra-violet (UV) hypersensitive xeroderma pigmentosum patients (XP) are markedly deficient in catalase activity resulting in high intracellular levels of hydrogen peroxide (H2O2) following UV irradiation. No direct correlation between catalase activity and repair ability was found since XP variant cells which are proficient in nucleotide excision repair (NER) showed activities as low as those found in NER deficient classical XP groups A and D. However, in contrast to the skin cancer prone XP patients, another NER deficient syndrome, trichothiodystrophy (TTD), which does not exhibit any cancer predisposition, was found to present normal catalase activity. Moreover, it was found that a variety of SV40 transformed human cell lines also showed decreased catalase activities. Our previous data showed that a molecular analysis of the normal, XP, TTD or transformed human fibroblast cell lines did not reveal any differences in levels of catalase transcription or amount of catalase protein subunits. These results incited us to examine the structure/function relationship of the tetrameric active enzyme form of catalase (which is the only one able to carry out H2O2 dismutation) with its cofactor NADPH. In the present study, we have measured the effects on catalase activity after adding NADPH either to acellular extracts or during cell culture of the different cell types. The NADPH levels were also quantified directly in intact cells using flow cytometry. Our results show a clear relationship between low catalase activity and striking decrease in intracellular NADPH levels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0891-5849
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
809-16
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Low catalase activity in xeroderma pigmentosum fibroblasts and SV40-transformed human cell lines is directly related to decreased intracellular levels of the cofactor, NADPH.
pubmed:affiliation
CEA/DSV/DPTE/LCG, Fontenay aux Roses, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't