Endotoxin-tolerance to the cytotoxicity toward a macrophage-like cell line, J774.1, induced by lipopolysaccharide and cycloheximide: role of p38 MAPK in induction of the cytotoxicity.
Novel endotoxin-tolerance was observed to the cytotoxycity induced by lipopolysaccharide (LPS) and cycloheximide (CHX) in an LPS-treated macrophage-like cell line, J774.1; preincubation of macrophages with low doses of LPS alone for 90 min almost completely prevented the apoptotic death in the second incubation with LPS and CHX. The first challenge of LPS affected neither the subsequent LPS binding nor the expression of CD14. Instead, phosphorylation of mitogen-activated proteinkinase (MAP kinases) involving p38, extracellular signal-regulated kinase 1/2 (Erk1/Erk2) and c-jun N-terminal kinase (JNK) in the second incubation with LPS and CHX were suppressed, suggesting that this endotoxin-tolerance was caused by down-regulation of LPS-signaling pathway leading to MAP kinase activation. On the other hand, LPS-induced cytotoxicity seemed to depend on the sustained phosphorylation of p38 MAP kinase; the addition of SB202190, an inhibitor of p38 MAP kinase activity, in the first incubation with LPS caused induction of the cytotoxicity in the second incubation with LPS and CHX or CHX alone, under which conditions increased phosphorylation of p38 MAP kinase without that of Erk1/Erk2 or JNK was observed. These results suggest that down-regulation of the p38 MAP kinase cascade in the first incubation with LPS is linked to induction of endotoxin-tolerance to the cytotoxicity with higher doses of LPS and CHX.
Karahashi
Hisae
H
Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Japan.
Amano
Fumio
F
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003513:Cycloheximide / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects; D004361:Drug Tolerance; D004731:Endotoxins / Q000494:pharmacology*; D005434:Flow Cytometry; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007093:Imidazoles / Q000494:pharmacology; D020287:In Situ Nick-End Labeling; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects*; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases
D004731:Endotoxins; D007093:Imidazoles; D008070:Lipopolysaccharides; D011500:Protein Synthesis Inhibitors; D011725:Pyridines; D003513:Cycloheximide; D011494:Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole