Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2007-5-2
pubmed:abstractText
Copper toxicity in the liver is mediated by free-radical generation, resulting in oxidative stress. To prevent toxic accumulation of copper, liver cells adapt to high copper levels. Here, we used microarray analysis to compare the adaptive responses on global gene expression in liver cells exposed to high copper levels in vitro and in vivo. In HepG2 cells we identified two clusters of upregulated genes over time, an "early" cluster that comprised metallothionein genes and a "late" cluster, highly enriched in genes involved in proteasomal degradation and in oxidative stress response. Concomitant with the "late" cluster, we detected a significant downregulation of several copper metabolism MURR1 domain (COMMD) genes that were recently implicated in copper metabolism and inhibition of nuclear transcription factor kappaB (NF-kappaB) signaling. As metal-induced oxidative stress increases NF-kappaB activity, our data suggest a role for reduced COMMD protein levels in prolonged activation of NF-kappaB, thus inducing cell survival. Mice exposed to a copper diet that highly exceeded normal daily intake accumulated only twofold more hepatic copper than control mice. Although a moderate, but significant upregulation of a set of 22 genes involved in immunity, iron and cholesterol metabolism was detected, these cannot account for direct mechanisms involved in copper excretion. In conclusion, we identified a novel set of genes that represent a delayed response to copper overload, thus providing insight into the adaptive transcriptional response to copper-induced oxidative stress.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0949-8257
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
495-507
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Gene expression profiling of liver cells after copper overload in vivo and in vitro reveals new copper-regulated genes.
pubmed:affiliation
Laboratory for Metabolic and Endocrine Diseases, University Medical Centre, Utrecht, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't