Article date: March 2004
By: Feng‐Ming Ho, Chih‐Chang Lai, Li‐Jiau Huang, Tsun Cheng Kuo, Chien M Chao, Wan‐Wan Lin in Volume 141, Issue 6, pages 1037-1047
The present study was undertaken to investigate the anti‐inflammatory effects of a synthetic compound, LCY‐2‐CHO, on the expression of inducible nitric oxide synthase (iNOS), COX‐2, and TNF‐α in murine RAW264.7 macrophages.
Within 1–30 μM, LCY‐2‐CHO concentration‐dependently inhibited lipopolysaccharide (LPS)‐induced nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor‐α (TNF‐α) formation, with IC50 values of 2.3, 1, and 0.8 μM, respectively. Accompanying inhibition of LPS‐induced iNOS, cyclooxygenase‐2 (COX‐2), and pro‐TNF‐α proteins was observed.
Reverse transcription‐polymerase chain reaction (RT–PCR) and promoter analyses indicated that iNOS expression was inhibited at the transcriptional level (IC50=2.3 μM), that inhibition of COX‐2 expression only partially depended on gene transcription (IC50=7.6 μM), and that TNF‐α transcription was unaffected.
Transcriptional assays revealed that activation of AP‐1, but not NF‐κB, was concomitantly blocked by LCY‐2‐CHO. Our results showed that LCY‐2‐CHO was capable of interfering with post‐transcriptional regulation, altering the stability of COX‐2 and TNF‐α mRNAs.
Since the 3′‐untranslated region (3′ UTR) of both COX‐2 and TNF‐α mRNA contains a p38 mitogen‐activated protein kinase (MAPK)‐regulated element involved in mRNA stability, we assessed the effect of LCY‐2‐CHO on p38 MAPK. Our data clearly indicated an inhibition (IC50=1.7 μM) of LPS‐mediated p38 MAPK activity, but not of extracellular signal‐regulated kinase (ERK) or c‐Jun N‐terminal kinase (JNK) activity. However, kinase assays ruled out a direct inhibition of p38 MAPK action. The selective p38 MAPK inhibitor, SB203580, inhibited the promoter activities of iNOS and COX‐2 rather than that of TNF‐α.
In conclusion, LCY‐2‐CHO downregulates inflammatory iNOS, COX‐2, and TNF‐α gene expression in macrophages through interfering with p38 MAPK and AP‐1 activation.
The present study was undertaken to investigate the anti‐inflammatory effects of a synthetic compound, LCY‐2‐CHO, on the expression of inducible nitric oxide synthase (iNOS), COX‐2, and TNF‐α in murine RAW264.7 macrophages.
Within 1–30 μM, LCY‐2‐CHO concentration‐dependently inhibited lipopolysaccharide (LPS)‐induced nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor‐α (TNF‐α) formation, with IC50 values of 2.3, 1, and 0.8 μM, respectively. Accompanying inhibition of LPS‐induced iNOS, cyclooxygenase‐2 (COX‐2), and pro‐TNF‐α proteins was observed.
Reverse transcription‐polymerase chain reaction (RT–PCR) and promoter analyses indicated that iNOS expression was inhibited at the transcriptional level (IC50=2.3 μM), that inhibition of COX‐2 expression only partially depended on gene transcription (IC50=7.6 μM), and that TNF‐α transcription was unaffected.
Transcriptional assays revealed that activation of AP‐1, but not NF‐κB, was concomitantly blocked by LCY‐2‐CHO. Our results showed that LCY‐2‐CHO was capable of interfering with post‐transcriptional regulation, altering the stability of COX‐2 and TNF‐α mRNAs.
Since the 3′‐untranslated region (3′ UTR) of both COX‐2 and TNF‐α mRNA contains a p38 mitogen‐activated protein kinase (MAPK)‐regulated element involved in mRNA stability, we assessed the effect of LCY‐2‐CHO on p38 MAPK. Our data clearly indicated an inhibition (IC50=1.7 μM) of LPS‐mediated p38 MAPK activity, but not of extracellular signal‐regulated kinase (ERK) or c‐Jun N‐terminal kinase (JNK) activity. However, kinase assays ruled out a direct inhibition of p38 MAPK action. The selective p38 MAPK inhibitor, SB203580, inhibited the promoter activities of iNOS and COX‐2 rather than that of TNF‐α.
In conclusion, LCY‐2‐CHO downregulates inflammatory iNOS, COX‐2, and TNF‐α gene expression in macrophages through interfering with p38 MAPK and AP‐1 activation.
British Journal of Pharmacology (2004) 141, 1037–1047. doi:10.1038/sj.bjp.0705700
DOI: 10.1038/sj.bjp.0705700
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