RAW細胞の継代数が破骨細胞分化誘導系に与える影響

RAW264.7cell

北海道歯学会

北海道歯学雑誌

Teeth movement after orthodontic treatment can be regarded as t he reaction of periodontal tissue to mechanical stress. By applying orthodontic force to the periodontium, bone addition is suppressed and bone resorption is promoted on the compression side. Furthermore, bone resorption is suppressed and bone addition is promoted on the traction side, resulting in bone remodeling. When we investigated the effect of RAW 264.7 (RAW) cells on the osteoclast differentiation-inducing system by directly applying mechanical stimulation to the cells, we showed the differentiation of osteoclasts by the number of passages of RAW cells. Additionally, there was a difference in induction. Therefore, in this study, we assessed the relationship between the passage number of RAW cells and the differentiation-inducing system of osteoclasts as there are no available reports in this regard. N10 R AW cells having a passage number <10 and N30 R AW cells having a passage number ¬30 were cultured for seven days in an osteoclast-inducing mediu m, and changes in the number of osteoclasts were observed. N10 osteoclasts differentiated from N10 RAW cells increased after peaking on the day 4 and then decreased. Similarly, N30 osteoclasts differentiated from N30 RAW cells increased after peaking on day 6 and then decreased. Next, as a result of the cell proliferation test, no significant difference was observed between N10 and N30 RAW cells. Real-time polymerase chain reaction (RT-PCR) was performed to investigate the differences in the expression levels of osteoclast-related genes including TRAP, RANK, CD47, NFATc1, DC-STAMP, OC-STAMP, Integrin αV, IntegrinβⅢ, CD11a, and CD11b. No significant difference was observed in RANK, NFATc1, and Integrin βⅢ expression levels on the day 3of culture. In contrast, it decreased signif icantly in the cell fusion factors (CD47, DC-STAMP, OC-STAMP, and Integrinα V) in N30 osteoclasts compared with those in N10 osteoclasts. These results suggest that cell fusion of osteoclasts is suppressed in N30 osteoclasts compared with N10 osteoclasts on day 3 of culture. The above results suggested that when using N10 osteoclasts, which differentiate rapidly into osteoclasts, and N30 osteoclasts, which differentiate slowly into osteoclasts, it is necessary to take advantage of their characteristics.