IADR Abstract Archives
Role of Porphyromonas gulae 41-kDa fimbriae in alveolar bone resorption
Objectives: Porphyromonas gulae is a black-pigmented anaerobic bacteria associated with canine periodontitis. We have previously reported that P. gulae ATCC 51700 had 41-kDa and 53-kDa fimbrial proteins. Fimbriae in particular have been suggested to play an important role in facilitating initial interaction between bacteria and the host. In this study, we examined the involvement of 41-kDa fimbrial protein from P. gulae in osteoclast differentiation and cytokine production.
Methods: Special pathogen-free 3-weeks-old male Sprague-Dawley rats were infected orally with P. gulae and alveolar bone loss was measured. The 41-kDa fimbriae were purified by a DEAE Sepharose CL-6B anion exchange column. Bone marrow cells from BALB/c mouse and MC3T3-G2/PA6 cells were cultured with 41-kDa fimbrial protein. BALB/c mouse peritoneal macrophages were stimulated with 41-kDa fimbrial protein. Levels of inflammatory cytokine production were determined by ELISA. To estimate osteoclast differentiation, mouse osteoclast precursors placed on dentine slices were cultured with 41-kDa fimbrial protein. Primary cultures of human gingival fibroblast were used in adherence assay.
Results: Rats orally infected with P. gulae ATCC 51700 exhibited significantly bone loss compared with that of sham-infected rats. Osteoclast differentiation was significantly enhanced with the treatment of 41-kDa fimbrial protein in a dose-dependent manner. The levels of IL-1β and TNF-α induced by 41-kDa fimbrial protein were similar to E. coli LPS (1 μg/ml). The total area of pits formed on the dentine slices was significantly greater when the osteoclasts were incubated with 41-kDa fimbrial protein. The levels of adherence of P gulae were 1.64% ± 0.20, 1.44% ± 0.21 and 0.86% ± 0.14 respectively.
Conclusions: These results suggest that P. gulae 41-kDa fimbriae may provoke an inflammatory response in the host and be involved in periodontal tissue breakdown.
Methods: Special pathogen-free 3-weeks-old male Sprague-Dawley rats were infected orally with P. gulae and alveolar bone loss was measured. The 41-kDa fimbriae were purified by a DEAE Sepharose CL-6B anion exchange column. Bone marrow cells from BALB/c mouse and MC3T3-G2/PA6 cells were cultured with 41-kDa fimbrial protein. BALB/c mouse peritoneal macrophages were stimulated with 41-kDa fimbrial protein. Levels of inflammatory cytokine production were determined by ELISA. To estimate osteoclast differentiation, mouse osteoclast precursors placed on dentine slices were cultured with 41-kDa fimbrial protein. Primary cultures of human gingival fibroblast were used in adherence assay.
Results: Rats orally infected with P. gulae ATCC 51700 exhibited significantly bone loss compared with that of sham-infected rats. Osteoclast differentiation was significantly enhanced with the treatment of 41-kDa fimbrial protein in a dose-dependent manner. The levels of IL-1β and TNF-α induced by 41-kDa fimbrial protein were similar to E. coli LPS (1 μg/ml). The total area of pits formed on the dentine slices was significantly greater when the osteoclasts were incubated with 41-kDa fimbrial protein. The levels of adherence of P gulae were 1.64% ± 0.20, 1.44% ± 0.21 and 0.86% ± 0.14 respectively.
Conclusions: These results suggest that P. gulae 41-kDa fimbriae may provoke an inflammatory response in the host and be involved in periodontal tissue breakdown.