Linked Life Data

16403949

Source:http://linkedlifedata.com/resource/pubmed/id/16403949

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-1-11
pubmed:abstractText
TNF-alpha induces oxidative stress by generating reactive oxygen species (ROS). This molecule elevates the expression of gamma-glutamylcysteine synthetase heavy subunit (gamma-GCS-HS). Lens epithelium-derived growth factor (LEDGF)/p75, a transcriptional protein, is inducible by oxidative stress and protects cells from various stresses by upregulating stress-responsive genes. This paper presents evidence that TNF-alpha elevates the expression of LEDGF and that LEDGF is one of the transactivators of gamma-GCS-HS gene. An analysis of the gamma-GCS-HS promoter sequence (-819 to +518 nt) revealed the presence of putative sites for LEDGF binding. Gel mobility assay confirmed the binding of LEDGF to the heat shock element (nGAAn) and the stress response element (A/TGGGGA/T) present in gamma-GCS-HS promoter. Transactivation experiments showed activation of gamma-GCS-HS promoter in cells overexpressing LEDGF or treated with a sublethal dose of TNF-alpha (20 ng/ml). Downregulation of gamma-GCS-HS promoter activity in cells transfected with LEDGF small interfering RNA validated the finding. Notably, cells treated with TNF-alpha (20 ng/ml) for 24 h had an increased abundance of LEDGF and gamma-GCS-HS mRNA and protein. In contrast, cells treated with TNF-alpha for longer periods or with higher concentrations of TNF-alpha showed reduced expression of LEDGF and gamma-GCS-HS and increased cellular death with higher ROS levels. Cells overexpressing LEDGF revealed elevated GSH levels (10-15%), a condition that may potentially eliminate the insult to cells induced by TNF-alpha. Thus TNF-alpha regulation of LEDGF may be physiologically important, as elevated expression of LEDGF increases the expression of endogenous gamma-GCS-HS gene, the catalytic subunit of the regulating enzyme in GSH biosynthesis that may constitute a protective mechanism in limiting oxidative stress induced by inflammatory cytokines.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0363-6143
pubmed:author
pubmed:issnType
Print
pubmed:volume
290
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C554-66
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:16403949-Animals, pubmed-meshheading:16403949-Apoptosis, pubmed-meshheading:16403949-Base Sequence, pubmed-meshheading:16403949-Cell Shape, pubmed-meshheading:16403949-Cell Survival, pubmed-meshheading:16403949-Cells, Cultured, pubmed-meshheading:16403949-Epithelial Cells, pubmed-meshheading:16403949-Glutamate-Cysteine Ligase, pubmed-meshheading:16403949-Humans, pubmed-meshheading:16403949-Intercellular Signaling Peptides and Proteins, pubmed-meshheading:16403949-Lens, Crystalline, pubmed-meshheading:16403949-Mice, pubmed-meshheading:16403949-Molecular Sequence Data, pubmed-meshheading:16403949-Mutation, pubmed-meshheading:16403949-Promoter Regions, Genetic, pubmed-meshheading:16403949-Protein Subunits, pubmed-meshheading:16403949-RNA, Messenger, pubmed-meshheading:16403949-RNA, Small Interfering, pubmed-meshheading:16403949-Recombinant Fusion Proteins, pubmed-meshheading:16403949-Transcriptional Activation, pubmed-meshheading:16403949-Tumor Necrosis Factor-alpha
pubmed:year
2006
pubmed:articleTitle
Regulation of heavy subunit chain of gamma-glutamylcysteine synthetase by tumor necrosis factor-alpha in lens epithelial cells: role of LEDGF/p75.
pubmed:affiliation
Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska 68198-5840, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural