Differential protein and mRNA expression of CaMKs during osteoclastogenesis and its functional implications

The calmodulin-dependent kinase (CaMK) family has been recently recognized to participate in the regulation of osteoclastogenesis. However, there are some controversial reports regarding the mRNA expression patterns of CaMKs during osteoclastogenesis, although the protein expression pattern of most CaMKs during osteoclastogenesis have not been studied. In the present study, we attempted to address this issue by using a mouse bone marrow monocyte model and parallel Western blotting and quantitative real-time PCR. Our results revealed some interesting expression patterns of CaMKs during the process. Among all CaMKs examined, only CaMKIIδ exhibited consistent expression patterns between its mRNA and protein with both rising remarkably during osteoclastogenesis. CaMKIV protein was not detectable during the first three days of cell culture, but it rose on Day 5. The CaMK inhibitor, KN93, subdued osteoclastogenesis during the first three days of cell culture, a time when CaMKIV was absent while other KN93-sensi...