Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2009-5-4
pubmed:abstractText
This article reports on a study of the effect of trichostatin A (TSA), an inhibitor of histone deacetylase, on lipopolysaccharide (LPS)-induced expression of inducible nitric oxide synthase (iNOS) in RAW 264.7 macrophages and its underlying mechanisms. TSA pretreatment potently diminishes LPS-stimulated nitric oxide (NO) release and both mRNA and protein levels of iNOS in macrophages. The effects of TSA and LPS on transcription factors binding to two LPS-responsive elements within the iNOS promoter, one binding the NF-kappaB site and the other the octamer element, were investigated. Results show that TSA did not alter the LPS-activated NF-kappaB activity demonstrated by the nuclear translocation of p50 and p65 and by a NF-kappaB-driven reporter gene expression system. In addition, neither TSA nor LPS changed the expression of Oct-1, a ubiquitously expressed octamer binding protein. However, TSA suppressed the LPS-induced expression of Oct-2, another octamer binding protein, at both mRNA and protein levels. Chromatin immunoprecipitation assays revealed that binding of Oct-2 to the iNOS promoter was enhanced by LPS treatment; however, pretreatment with TSA resulted in loss of this binding. Moreover, forced expression of Oct-2 by transfection of pCG-Oct-2 plasmid restored the TSA-suppressed iNOS expression elevated by LPS stimulation, further indicating that Oct-2 activation is a crucial step for transcriptional activation of the iNOS gene in response to LPS stimulation in macrophages. This study demonstrates that TSA diminishes iNOS expression in LPS-treated macrophages by inhibiting Oct-2 expression and thus reducing the production of NO.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0363-6143
pubmed:author
pubmed:issnType
Print
pubmed:volume
296
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C1133-9
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
The essential role of Oct-2 in LPS-induced expression of iNOS in RAW 264.7 macrophages and its regulation by trichostatin A.
pubmed:affiliation
Graduate Institute of Medical Sciences, Taipei Medical University, Taipei 110, Taiwan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't