title: Hemoglobin and LPS act in synergy to amplify the inflammatory response.
abstract: Vascular disruption and bleeding during periodontitis likely increase the levels of hemoglobin in gingival crevicular fluid. The aim of this study was to investigate the effect of hemoglobin on the inflammatory responses of human macrophages stimulated with lipopolysaccharides (LPS) isolated from periodontopathogens. The production of interleukin-1 beta (IL-1beta), IL-6, IL-8, and tumor necrosis factor alpha (TNF-alpha) by macrophages following challenges with Porphyromonas gingivalis and Fusobacterium nucleatum LPS in the presence or absence of human hemoglobin was analyzed by ELISA. The effect of hemoglobin on LPS-binding to macrophages was evaluated with (3)H-LPS. Hemoglobin and LPS from periodontopathogens acted in synergy to stimulate the production of high levels of IL-1beta, IL-6, IL-8, and TNF-alpha by macrophages. Hemoglobin also enhanced LPS-binding to macrophages. This study suggests that hemoglobin contributes to increases in the levels of pro-inflammatory mediators in periodontal sites by acting in synergy with LPS from periodontopathogens, thus favoring the progression of periodontitis.
authors.affiliation: Groupe de Recherche en Ecologie Buccale, Faculté de Médecine Dentaire, Université Laval, Quebec City, Quebec, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Bodet
authors.forename: F
authors.initials: F
authors.lastname: Chandad
authors.forename: D
authors.initials: D
authors.lastname: Grenier
mesh_terms: D016207:Cytokines / Q000096:biosynthesis*; D016967:Fusobacterium nucleatum / Q000737:chemistry; D006454:Hemoglobins / Q000494:pharmacology* / Q000502:physiology; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism* / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D010518:Periodontitis / Q000378:metabolism*; D016966:Porphyromonas gingivalis / Q000737:chemistry; D020298:U937 Cells
chemical_list: D016207:Cytokines; D006454:Hemoglobins; D018836:Inflammation Mediators; D008070:Lipopolysaccharides