L-type calcium channels play a crucial role in the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells

L-type voltage-dependent Ca2+ channels (VDCCL) play an important role in the maintenance of intracellular calcium homeostasis, and influence multiple cellular processes. They have been confirmed to contribute to the functional activities of osteoblasts. Recently, VDCCL expression was reported in mesenchymal stem cells (MSCs), but the role of VDCCL in MSCs is still undetermined. The aim of this study was to determine whether VDCCL may be regarded as a new regulator in the proliferation and osteogenic differentiation of rat MSC (rMSCs). In this study, we examined functional Ca2+ currents (I-Ca) and mRNA expression of VDCCL in rMSCs, and then suppressed VDCCL using nifedipine (Nif), a VDCCL blocker, to investigate its role in rMSCs. The proliferation and osteogenic differentiation of MSCs were analyzed by MIT, flow cytometry, alkaline phosphatase (ALP), Alizarin Red S staining, RT-PCR, and real-time PCR assays. We found that Nif exerts antiproliferative and apoptosis-inducing effects on rMSCs. ALP activity and mineralized nodules were significantly decreased after Nif treatment. Moreover, the mRNA levels of the osteogenic markers, osteocalcin (OCN), bone sialoprotein (BSP), and runt-related transcription factor 2 (Runx2), were also down-regulated. In addition, we transfected alpha 1C-siRNA into the cells to further confirm the role of VDCCL in rMSCs, and a similar effect on osteogenesis was found. These results suggest that VDCCL plays a crucial role in the proliferation and osteogenic differentiation of rMSCs. (C) 2012 Elsevier Inc. All rights reserved.