Streptococcus gordonii induces bone resorption by increasing osteoclast differentiation and reducing osteoblast differentiation.

Abstract

Streptococcus gordonii is commonly found in the periapical endodontic lesions of patients with apical periodontitis, a condition characterized by inflammation and periapical bone loss. Since bone metabolism is controlled by osteoclastic bone resorption and osteoblastic bone formation, we investigated the effects of S. gordonii on the differentiation and function of osteoclasts and osteoblasts. For the determination of bone resorption activity in vivo, collagen sheets soaked with heat-killed S. gordonii were implanted on mouse calvaria, and the calvarial bones were scanned by micro-computed tomography. Mouse bone marrow-derived macrophages (BMMs) were stimulated with M-CSF and RANKL for 2 days and then differentiated into osteoclasts in the presence or absence of heat-killed S. gordonii. Tartrate-resistant acid phosphatase staining was performed to determine osteoclast differentiation. Primary osteoblast precursors were differentiated into osteoblasts with ascorbic acid and β-glycerophosphate in the presence or absence of heat-killed S. gordonii. Alkaline phosphatase staining and alizarin red S staining were conducted to determine osteoblast differentiation. Western blotting was performed to examine the expression of transcription factors including c-Fos, NFATc1, and Runx2. Heat-killed S. gordonii induced bone destruction in a mouse calvarial implantation model. The differentiation of RANKL-primed BMMs into osteoclasts was enhanced in the presence of heat-killed S. gordonii. Heat-killed S. gordonii increased the expression of c-Fos and NFATc1, which are essential transcription factors for osteoclast differentiation. On the other hand, heat-killed S. gordonii inhibited osteoblast differentiation and reduced the expression of Runx2, an essential transcription factor for osteoblast differentiation. S. gordonii exerts bone resorptive activity by increasing osteoclast differentiation and reducing osteoblast differentiation, which may be involved in periapical bone resorption.

• Authors: Ok-Jin Park, Jiseon Kim, Hyun Young Kim, Yeongkag Kwon, Cheol-Heui Yun, Seung Hyun Han
• Journal: Microbial pathogenesis (Microb Pathog) Vol. 126 Pg. 218-223 (Jan 2019) ISSN: 1096-1208 [Electronic] England
• PMID: 30414445 (Publication Type: Journal Article)
• Copyright: Copyright © 2018 Elsevier Ltd. All rights reserved.

Chemical References

• Core Binding Factor Alpha 1 Subunit
• Cytokines
• Glycerophosphates
• NFATC Transcription Factors
• Nfatc1 protein, mouse
• Proto-Oncogene Proteins c-fos
• RANK Ligand
• Runx2 protein, mouse
• Tnfsf11 protein, mouse
• Transcription Factors
• bone resorption factor
• Macrophage Colony-Stimulating Factor
• Alkaline Phosphatase
• Ascorbic Acid
• beta-glycerophosphoric acid

Topics

• Alkaline Phosphatase
• Animals
• Ascorbic Acid (metabolism)
• Bone Resorption (diagnostic imaging, microbiology)
• Cell Differentiation
• Core Binding Factor Alpha 1 Subunit (metabolism)
• Cytokines
• Disease Models, Animal
• Glycerophosphates (metabolism)
• Macrophage Colony-Stimulating Factor (metabolism)
• Macrophages
• Male
• Mice
• Mice, Inbred C57BL
• NFATC Transcription Factors (metabolism)
• Osteoblasts
• Osteoclasts
• Osteogenesis
• Periapical Periodontitis
• Proto-Oncogene Proteins c-fos (metabolism)
• RANK Ligand (metabolism)
• Streptococcus gordonii (pathogenicity)
• Transcription Factors
• Up-Regulation
• X-Ray Microtomography