title: IKK NBD peptide inhibits LPS induced pulmonary inflammation and alters sphingolipid metabolism in a murine model.
abstract: Airway epithelial NF-κB is a key regulator of host defence in bacterial infections and has recently evolved as a target for therapeutical approaches. Evidence is accumulating that ceramide, generated by acid sphingomyelinase (aSMase), and sphingosine-1-phosphate (S1-P) are important mediators in host defence as well as in pathologic processes of acute lung injury. Little is known about the regulatory mechanisms of pulmonary sphingolipid metabolism in bacterial infections of the lung. The objective of this study was to evaluate the influence of NF-κB on sphingolipid metabolism in Pseudomonas aeruginosa LPS-induced pulmonary inflammation. In a murine acute lung injury model with intranasal Pseudomonas aeruginosa LPS we investigated TNF-α, KC (murine IL-8), IL-6, MCP-1 and neutrophilic infiltration next to aSMase activity and ceramide and S1-P lung tissue concentrations. Airway epithelial NF-κB was inhibited by topically applied IKK NBD, a cell penetrating NEMO binding peptide. This treatment resulted in significantly reduced inflammation and suppression of aSMase activity along with decreased ceramide and S1-P tissue concentrations down to levels observed in healthy animals. In conclusion our results confirm that changes in sphingolipid metabolim due to Pseudomonas aeruginosa LPS inhalation are regulated by NF-κB translocation. This confirms the critical role of airway epithelial NF-κB pathway for the inflammatory response to bacterial pathogens and underlines the impact of sphingolipids in inflammatory host defence mechanisms.
authors.affiliation: Department of Paediatrics, University Hospital Schleswig-Holstein, and Department of Anatomy, CAU University of Kiel, Campus Kiel, Schwanenweg 20, 24105 Kiel, Germany. v.bismarck@pediatrics.uni-kiel.de
authors.forename: Philipp
authors.initials: P
authors.lastname: von Bismarck
authors.forename: Supandi
authors.initials: S
authors.lastname: Winoto-Morbach
authors.forename: Mona
authors.initials: M
authors.lastname: Herzberg
authors.forename: Ulrike
authors.initials: U
authors.lastname: Uhlig
authors.forename: Stefan
authors.initials: S
authors.lastname: Schütze
authors.forename: Ralph
authors.initials: R
authors.lastname: Lucius
authors.forename: Martin F
authors.initials: MF
authors.lastname: Krause
mesh_terms: D055371:Acute Lung Injury / Q000276:immunology / Q000503:physiopathology*; D000818:Animals; D057846:Cell-Penetrating Peptides / Q000494:pharmacology*; D002518:Ceramides / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D051550:I-kappa B Kinase / Q000378:metabolism; D007249:Inflammation / Q000276:immunology / Q000503:physiopathology; D008070:Lipopolysaccharides; D008246:Lysophospholipids / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000276:immunology; D013107:Sphingolipids / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D057846:Cell-Penetrating Peptides; D002518:Ceramides; C575063:IKK NBD peptide; D008070:Lipopolysaccharides; D008246:Lysophospholipids; C467063:NBD peptide, mouse; D016328:NF-kappa B; D010455:Peptides; D013107:Sphingolipids; C060506:sphingosine 1-phosphate; D051550:I-kappa B Kinase; D013110:Sphingosine