Cementoblast Gene Expression is Regulated by Porphyromonas gingivalis Lipopolysaccharide Partially via Toll-like Receptor-4/MD-2

• Published in: Journal of dental research Vol. 83; no. 8; pp. 602 - 607
• Main Authors: Nociti, F.H., Foster, B.L., Barros, S.P., Darveau, R.P., Somerman, M.J.
• Format: Journal Article
• Language: English
• Published: United States SAGE Publications 01.08.2004; SAGE PUBLICATIONS, INC
• Subjects: Animals; Antigens, Ly - drug effects; Antigens, Ly - genetics; Antigens, Ly - metabolism; Blotting, Northern; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cells, Cultured; Dental Cementum - cytology; Dental Cementum - drug effects; Dental Cementum - metabolism; Dentistry; Dose-Response Relationship, Drug; Gene Expression Regulation - drug effects; Glycoproteins - genetics; Glycoproteins - metabolism; Lipopolysaccharide Receptors - drug effects; Lipopolysaccharide Receptors - genetics; Lipopolysaccharide Receptors - metabolism; Lipopolysaccharides - pharmacology; Lymphocyte Antigen 96; Membrane Glycoproteins - drug effects; Membrane Glycoproteins - genetics; Membrane Glycoproteins - metabolism; Mice; Mice, Transgenic; NF-kappa B - metabolism; Osteocalcin - genetics; Osteocalcin - metabolism; Osteoclasts - drug effects; Osteoclasts - metabolism; Osteopontin; Osteoprotegerin; Porphyromonas gingivalis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cell Surface - drug effects; Receptors, Cell Surface - genetics; Receptors, Cell Surface - metabolism; Receptors, Cytoplasmic and Nuclear - genetics; Receptors, Cytoplasmic and Nuclear - metabolism; Receptors, Tumor Necrosis Factor; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; Sialoglycoproteins - genetics; Sialoglycoproteins - metabolism; Toll-Like Receptor 4; Toll-Like Receptors; Up-Regulation - drug effects; Porphyromonas gingivalis; cytokines; lipopolysaccharides; cementoblasts
• ISSN: 0022-0345; 1544-0591
• DOI: 10.1177/154405910408300804

Lipopolysaccharides are potent inflammatory mediators considered to contribute to destruction of periodontal tissues. Here, we hypothesized that Porphyromonas gingivalis lipopolysaccharide (P-LPS) treatment would regulate gene expression in murine cementoblasts through Toll-like receptor 4. Real-time (RT)-PCR and Northern blot analysis indicated that P-LPS decreased expression of transcripts for osteocalcin (OCN) and receptor activator of nuclear factor κB ligand (RANKL). In contrast, a dose-dependent up-regulation in mRNA levels for osteopontin (OPN) and osteoprotegerin (OPG) was observed. Similarly, ELISA demonstrated decreased RANKL and increased OPG levels. A monoclonal antibody specific for mouse TLR-4/MD-2 partially neutralized the P-LPS effect on cementoblasts. These results indicate that exposure of cementoblasts to P-LPS can alter cell function by regulating markers of osteoclastic activity (e.g., RANKL/OPG), thereby potentially affecting the inflammation-associated resorption of mineralized tissues.