A pathway through interferon‐γ is the main pathway for induction of nitric oxide upon stimulation with bacterial lipopolysaccharide in mouse peritoneal cells

Abstract

Production of nitric oxide (NO) in response to bacterial lipopolysaccharide (LPS) was investigated using cultures of mouse peritoneal exudate cells (PEC) and the macrophage cell line RAW264.7. In the presence of anti-(interferon-c) (IFN-c), NO production was markedly suppressed in the PEC culture but not in the RAW264.7 culture. In the PEC culture, LPS induced both IFN-c production and activation of IFN response factor-1, which leads to the gene expression of inducible NO synthase, but neither was induced in the culture of RAW264.7 cells. In addition to anti-(IFN-c), antibodies against interleukin (IL)-12 and IL-18 showed a suppressive effect on LPS-induced NO production in the PEC culture, and these antibodies in synergy showed strong suppression. Stimulation of the PEC culture with IL-12 or IL-18 induced production of IFN-c and NO, and these cytokines, in combination, exhibited marked synergism. Stimulation of the culture with IFN-c induced production of NO, but not IL-12. The macrophage population in the PEC, prepared as adherent cells, responded well to LPS for IL-12 production, but weakly for production of IFN-c and NO. The macrophages also responded well to IFN-c for NO production. For production of IFN-c by stimulation with LPS or IL-12 + IL-18, nonadherent cells were required in the PEC culture. Considering these results overall, the indirect pathway, through the production of intermediates (such as IFN-c-inducing cytokines and IFN-c) by the cooperation of macrophages with nonadherent cells, was revealed to play the main role in the LPS-induced NO production pathway, as opposed to the direct pathway requiring only a macrophage population.

Regulation of Lipopolysaccharide-Induced Interleukin-12 Production by Activation of Repressor Element GA-12 through Hyperactivation of the ERK Pathway

“…In a previous paper (22), we demonstrated that mouse RAW264.7 cells did not produce IL-12 in response to LPS while they responded normally in inducing several cytokines other than IL-12. The impaired responses of RAW264.7 cells to LPS-induced IL-12 production were investigated in this study to elucidate the regulatory mechanisms.…”

Embryonic exposure to cypermethrin induces apoptosis and immunotoxicity in zebrafish (Danio rerio)

“…[35,39,40]. Previous studies suggested that NO is produced via the induction of iNOS by macrophages in response to outside stimuli [41].…”

Analysis of inflammatory and lipid metabolic networks across RAW264.7 and thioglycolate-elicited macrophages

“…Peroxisome proliferator-activated receptor (PPAR) ␥ , a nuclear receptor with anti-infl ammatory functions, is barely detectable in RAW264.7 cells ( 12,13 ), but it is highly expressed in TGEM cells ( 13 ). IL-12p70 and interferon (IFN)-␥ are not produced by RAW264.7 cells upon LPS stimulation ( 14 ). Caveolin-1 (Cav1), which is essential for the assembly of caveolae and involved in the maintenance of cellular cholesterol homeostasis and lipid transport ( 15 ), is upregulated in peritoneal macrophages in response to LPS but downregulated in RAW264.7 cells ( 16,17 ).…”