Compound FLZ inhibits lipopolysaccharide-induced inflammatory effects via down-regulation of the TAK-IKK and TAK-JNK/p38MAPK pathways in RAW264.7 macrophages.
OBJECTIVE
The aim of this study was to investigate the effect of the squamosamide derivative FLZ (N-2-(4-hydroxy-phenyl)-ethyl-2-(2,5-dimethoxy-phenyl)-3-(3-methoxy-4-hydroxy-phenyl)-acrylamide) on lipopolysaccharide (LPS)-induced inflammatory mediator production and the underlying mechanism in RAW264.7 macrophages.


METHODS
RAW264.7 cells were preincubated with non-toxic concentrations of compound FLZ (1, 5, and 10 micromol/L) for 30 min and then stimulated with 10 microg/L LPS. The production of nitric oxide (NO), the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2), and the activation of nuclear factor kappa-B (NF-kappaB) and mitogen-activated protein kinase (MAPK) pathways were examined.


RESULTS
FLZ significantly inhibited the LPS-induced production of NO, as well as the expression of iNOS and COX-2 at both the RNA and the protein levels in RAW264.7 cells. The LPS-induced increase in the DNA binding activity of NF-kappaB and activator protein 1 (AP-1), the nuclear translocation of NF-kappaB p65, the degradation of the inhibitory kappaBalpha protein (IkappaBalpha) and the phosphorylation of IkappaBalpha, IkappaB kinase (IKK) alpha/beta, c-Jun NH(2)-terminal kinase (JNK) and p38 MAPKs were all suppressed by FLZ. However, the phosphorylation of extracellular signal-regulated kinase (ERK) was not affected. Further study revealed that FLZ inhibited the phosphorylation of transforming growth factor-beta (TGF-beta)-activated kinase 1 (TAK1), which is an upstream signaling molecule required for IKKalpha/beta, JNK and p38 activation.


CONCLUSIONS
FLZ inhibited the LPS-induced production of inflammatory mediators at least partly through the downregulation of the TAK-IKK and TAK-JNK/p38MAPK pathways.
Pang
Hong-Yan
HY
Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Liu
Gang
G
Liu
Geng-Tao
GT
D000818:Animals; D044482:Benzeneacetamides / Q000737:chemistry / Q000494:pharmacology*; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D004789:Enzyme Activation; D051550:I-kappa B Kinase / Q000235:genetics / Q000378:metabolism*; D007249:Inflammation / Q000276:immunology; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000276:immunology*; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D051379:Mice; D015394:Molecular Structure; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D000099151:MAP Kinase Kinase Kinase 7
D044482:Benzeneacetamides; D051546:Cyclooxygenase 2; D051550:I-kappa B Kinase; D048031:JNK Mitogen-Activated Protein Kinases; D008070:Lipopolysaccharides; D020930:MAP Kinase Kinase Kinases; D016328:NF-kappa B; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D010636:Phenols; D048051:p38 Mitogen-Activated Protein Kinases; D000099151:MAP Kinase Kinase Kinase 7; C084439:squamosamide