2007 Fiscal Year Final Research Report Summary
Application of Cre-loxP system for elucidation of mechanisms in bone remodeling during tooth movement
| Project/Area Number |
18390557
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Orthodontic/Pediatric dentistry
|
|---|
| Research Institution | Matsumoto Dental University |
|---|
Principal Investigator |
KOBAYASHI Yasuhiro Matsumoto Dental University, Graduate school of oral medicine, Associate professor (20264252)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Naoyuki Matsumoto Dental University, Graduate school of oral medicine, Professor (90119222)
YAMASHITA Teruhiro Matsumoto Dental University, Institute for Oral Science, Lecturer (90302893)
NAKAMICHI Yuko Matsumoto Dental University, Institute for Oral Science, Assistant professor (20350829)
MIZOGUCHI Toshihide Matsumoto Dental University, Institute for Oral Science, Lecturer (90329475)
NINOMIYA Tadashi Matsumoto Dental University, Institute for Oral Science, Assistant professor (00360222)
|
|---|
| Project Period (FY) |
2006 – 2007
|
| Keywords | orthodontics / RANK / Cre recombinase / osteoclast precursors / ノックインマウス |
|---|
| Research Abstract |
When orthodontic forces are applied to alveolar bones, cyclooxigenase-2 is inducibly expressed and then prostaglandin E2 (PGE2) is synthesized. PGE2 is reported to have a potent stimulator for both bone resorption and bone formation. These findings suggest that PGE2-PKA signals have an important role in osteoclast differentiation as well as osteoblast differentiation in orthodontic tooth movement. Mechanisms that PGE2-PKA signals discriminate between bone resorption in compressive site and bone formation in tensile site are largely unknown. The purpose of this project is to elucidate mechanisms for regulation of bone remodeling by PGE2-PKA signals in vivo when using Cre-loxP systems. We developed mice expressing EGFP-Cre fusion proteins in early stage of osteoclast differentiation (RANK-EGFPCre mice). IRES-EGFP-Cre cDNA including Neo cassette was inserted between a stop codon and polyA sequences in RANK gene. To test whether cre-recombinase was expressed and worked in osteoclast precursor cells, reporter gene expressing LacZ only after Cre-mediated excision of loxP-flanked DNA sequence was introduce into the RANK-EGFPCre mice, and LacZ/RANK-EGFPCre mice were obtained. Femurs of LacZ/ RANK-EGFPCre mice were histo-chemically analyzed. A lot of LacZ positive cells inducing osteoclasts were detected in bone marrow of LacZ/RANK-EGFPCre mice but not in LacZ/wild type mice. Western blot analyses show that EGFP-Cre protein was expressed in osteoclast precursor cells. Together, RANK-EGFPCre mice are a powerful tool for analysis of distribution of osteoclast precursor cells in periodontal tissue during orthodontic tooth movement
|
