ABSTRACT
Objective:To study the expression profiles and the role of Ca2+/calmodulin-dependent protein kinase Ⅱγ (CaMKⅡγ) during osteoclast differentiation.Methods:Mouse RAW264.7 cells were induced for osteoclastogenesis with 50 ng/mL receptor activator of nuclear factor-κB ligand (RANKL) and the cells were harvested at 0,1,3 and 5 days after induction.Tartrate-resistant acid phosphotase staining was performed to verify osteoclasts formation.RT-PCR,Western blot and immunofluorescent cytochemistry were used to detect the CaMKⅡγ gene expression during osteoclastogenesis.Results:The osteodasts were formed at day 3 under RANKL induction and more osteoclasts were observed at day 5.At day 0,1,3 and 5,the relative level of CaMKⅡγ mRNA were (1.067±0.179),(1.840±0.070),(9.493±0.453) and (30.767±0.573),respectively,and the relative protein level were (0.454±0.065),(0.613±0.021),(0.858±0.019) and (0.980±0.023),respectively.CaMKⅡγ expression was increased in a time-dependent manner except relative protein level at day 1 (P＜0.01),which showed no significant difference at day 0 (P＞0.05).Immunofluorescence assay showed that CaMKⅡγ protein was also increased with differentiation of osteoclasts.Conclusion:The CaMKⅡγ expression was increased in a time-depended manner during osteoclast differentiation and it might play a vital role during osteoclastogenesis.
ABSTRACT
Serum tartrate-resistant acid phosphatase-5b (TRAP-5b) is a marker reflecting bone absorption. The results showed that serum TRAP-5b level was higher in postmenopausal than that in premenopausal normal women (P