RESUMO
A strain of Bacteroides fragilis, isolated from the marmoset Callithrix penicillata, produced protein(s) with bacteriocin activity (fragicilin). Two active fractions (36 and 150 kDa) were isolated by chromatography. The bacteriocin exhibited iso- and heteroantagonism. It remained stable between pH 3 and 10 and at 60 degrees C for 24 h. Pronase, trypsin, proteinase K and type VII protease inactivated the bacteriocin, giving evidence of its protein nature.
Assuntos
Bacteriocinas/isolamento & purificação , Bacteroides fragilis/química , Callithrix/microbiologia , Animais , Bacteriocinas/farmacologia , Bacteroides fragilis/efeitos dos fármacos , Bacteroides fragilis/isolamento & purificação , Cromatografia em Agarose , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Streptococcus pyogenes/efeitos dos fármacos , Streptococcus sanguis/efeitos dos fármacos , TemperaturaRESUMO
Nitric oxide (NO) and reactive oxygen species (ROS) are key molecules in resistance to pathogens. Little is known about their role in pathogenesis of periapical lesions. To address this issue, we induced periapical lesions in mice lacking nitric oxide synthase (iNOS(-/-)) or phagocyte oxidase (PHOX(-/-)). iNOS(-/-) mice expressed higher levels of IL-1ß, TNF-α, RANK, RANKL, and MCP-1 than C57BL/6 and PHOX(-/-). Apical thickening of the periodontal ligament was also greater in iNOS(-/-) compared with other groups. Interestingly, ROS production did not interfere in periapical lesion progression, but seemed to be essential for the appearance of multinucleated TRAP-positive cells. Thus, periapical lesion progression in iNOS(-/-) was associated with an imbalance of pro-inflammatory cytokines (IL-1ß and TNF-α), bone-resorptive modulators (RANK and RANKL), and MCP-1. We conclude that NO, but not ROS, controls progression of bone resorption in a murine experimental model of apical periodontitis.
Assuntos
Perda do Osso Alveolar/enzimologia , NADPH Oxidases/fisiologia , Óxido Nítrico Sintase Tipo II/fisiologia , Periodontite Periapical/enzimologia , Fagócitos/enzimologia , Fosfatase Ácida/análise , Perda do Osso Alveolar/metabolismo , Perda do Osso Alveolar/patologia , Animais , Biomarcadores/análise , Quimiocina CCL2/análise , Citocinas/análise , Modelos Animais de Doenças , Progressão da Doença , Mediadores da Inflamação/análise , Interleucina-1beta/análise , Isoenzimas/análise , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Knockout , Óxido Nítrico/fisiologia , Periodontite Periapical/patologia , Ligamento Periodontal/enzimologia , Ligamento Periodontal/patologia , Ligante RANK/análise , Espécies Reativas de Oxigênio/farmacologia , Receptor Ativador de Fator Nuclear kappa-B/análise , Fosfatase Ácida Resistente a Tartarato , Fator de Necrose Tumoral alfa/análiseRESUMO
A new intracellular bacteriocin isolated from a human fecal strain of Bacteroides ovatus was partially purified through ammonium sulfate precipitation, ion exchange chromatography, gel filtration, and preparative polyacrylamide gel electrophoresis (PAGE). The bacteriocin is stable at a pH range of 3-10, at 60 degrees C for 24 h, and at -70 degrees C for 6 months. It is inactivated by proteolytic enzymes. The molecular weight, estimated by sodium dodecyl sulfate--PAGE, is 78 kDa. Fifty strains of the Bacteroides fragilis group were isolated from fecal samples, and 41 of the isolates were shown to produce an antagonistic substance against at least 1 indicator strain. Iso-, auto-, and hetero-antagonisms were observed.