title: N-methyl pyrrolidone (NMP) inhibits lipopolysaccharide-induced inflammation by suppressing NF-κB signaling.
abstract: OBJECTIVE
  N-methyl pyrrolidone (NMP), a small bioactive molecule, stimulates bone formation and inhibits osteoclast differentiation and bone resorption. The present study was aimed to evaluate the anti-inflammatory potentials of NMP on the inflammatory process and the underlying molecular mechanisms in RAW264.7 macrophages.
  
  
  METHODS
  RAW264.7 macrophages and mouse primary bone marrow macrophages (mBMMs) were used as an in vitro model to investigate inflammatory processes. Cells were pre-treated with or without NMP and then stimulated with lipopolysaccharides (LPS). The productions of cytokines and NO were determined by proteome profiler method and nitrite analysis, respectively. The expressions of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were measured by Western blotting and/or qPCR. Western blot, ELISA-base reporter assay, and immunofluorescence were used to evaluate the activation of MAP kinases and NF-κB.
  
  
  RESULTS
  LPS-induced mRNA expressions of TNF-α, IL-1β, IL-6, iNOS, and COX-2 were inhibited by NMP in a dose-dependent manner. NMP also suppressed the LPS-increased productions of iNOS and NO. The proteome profiler array showed that several cytokines and chemokines involved in inflammation and up-regulated by LPS stimulation were significantly down-regulated by NMP. Additionally, this study shows that the effect of NMP is mediated through down-regulation of NFκB pathway.
  
  
  CONCLUSIONS
  Our results show that NMP inhibits the inflammatory mediators in macrophages by an NFκB-dependent mechanism, based on the epigenetical activity of NMP as bromodomain inhibitor. In the light of its action on osteoblast and osteoclast differentiation process and its anti-inflammatory potential, NMP might be used in inflammation-related bone loss.
authors.affiliation: Department of Cranio-Maxillofacial and Oral Surgery, Oral Biotechnology and Bioengineering, Center for Dental Medicine, Zentrum für Zahnmedizin, University Zürich, Plattenstrasse 11, 8032, Zürich, Switzerland, Chafik.Ghayor@usz.ch.
authors.forename: Chafik
authors.initials: C
authors.lastname: Ghayor
authors.forename: Bebeka
authors.initials: B
authors.lastname: Gjoksi
authors.forename: Barbara
authors.initials: B
authors.lastname: Siegenthaler
authors.forename: Franz E
authors.initials: FE
authors.lastname: Weber
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis; D007249:Inflammation / Q000139:chemically induced* / Q000517:prevention & control*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000633:toxicity; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000187:drug effects*; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis; D011760:Pyrrolidinones / Q000494:pharmacology*; D000067996:RAW 264.7 Cells / Q000187:drug effects; D051996:Transcription Factor RelA / Q000096:biosynthesis
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016207:Cytokines; D008070:Lipopolysaccharides; D016328:NF-kappa B; D011760:Pyrrolidinones; D051996:Transcription Factor RelA; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D020928:Mitogen-Activated Protein Kinases; C038678:N-methylpyrrolidone