Dynamic phase of Alveolar Bone-derived Osteoblasts at High Calcium Ion Concentration with Bone Resorption Accentuation.

2000 Fiscal Year Final Research Report Summary

• Project/Area Number: 11671887
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 病態科学系歯学(含放射線系歯学)
• Research Institution: Nihon-University
• Principal Investigator: MAENO Masao Nihon University School of Dentistry, Associate Professor, 歯学部, 助教授 (60147618)
• Co-Investigator(Kenkyū-buntansha): SUZUKI Naoto Nihon University School of Dentistry, Lecture, 歯学部, 講師 (10226532) ; ITO Koich Nihon University School of Dentistry, Professor, 歯学部, 教授 (90102607) ; OTSUKA Kichibee Nihon University School of Dentistry, Professor, 歯学部, 教授 (50059995) ; ITO Emi Nihon University School of Dentistry, Assistant, 歯学部, 助手 (90297838) ; OHSHIMA Mitsuhiro Nihon University School of Dentistry, Assistant, 歯学部, 助手 (30194145)
• Project Period (FY): 1999 – 2000
• Keywords: bone remodeling / high calcium ion concentration / matrix metalloprotease / alveolar bone / osteoclast differentiation factor / osteoclastogenesis inhibitory factor / osteoblast-like cells / tissue inhibitor of matrix metalloprotease

Research Abstract

Human alveolar bone-derived osteoblast-like cells were obtained from alveolar bone fragments of young (18-24 years old) and old (55-68 years old) patients. The cells that migrated from individual bone fragment were harvested separately and subcultured up to the third passage. After seeding the cells in 6-well microplates, the cells were cultured with α-MEM containing 10% FBS and 1.8 to 10 mM CaCl_2 for up to 72 h. The gene expression of extracellular matrix proteins, MMPs, TIMPs, osteoclast differentiation factor (ODF) and osteoclastogenesis inhibitory factor was examined at mRNA level by quantitative RT-PCR using specific primers. The following results were obtained.
1. Although logarithmic cell proliferation was recognized in low Ca^<2+> concentration (1.8 and 2.5 mM), it was not recognized in high Ca^<2+> concentration (5 and 10 mM).
2. Gene expression of bone sialoprotein and osteocalcin was increased by addition of high Ca^<2+> concentration in both age groups. Expression of type I collagen and osteonectin was not affected by addition of Ca^<2+> in both age groups.
3. Expression of MMP-1 and MMP-2 was not affected by addition of Ca^<2+> in both age groups. MMP-3 expression was not detected with or without Ca^<2+> in both age groups.
4. Expression of TIMP-1 and TIMP-2 was increased in Ca^<2+> concentration-dependent in both age groups, and the effects were recognized markedly in young age group.
5. Expression of OCIF was increased by addition of high Ca^<2+> concentration in both age groups, and the effects were recognized markedly in young age group. In contrast, ODF expression was not detected with or without Ca^<2+> in both age groups.