Abed Elie, Labelle Dominique, Martineau Corine, Loghin Andrew, Moreau Robert
Laboratoire du Métabolisme osseux, BioMed, Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, Québec, Canada.
Mol Membr Biol. 2009 Apr;26(3):146-58. doi: 10.1080/09687680802612721. Epub 2008 Dec 27.
The preservation of bone mass relies on adequate proliferation, differentiation, secretion of matrix proteins and rate of apoptosis of the bone-forming osteoblasts. Although growing body of evidence indicates that the transient receptor potential (TRP) channels play important roles in numerous cellular functions, limited information is available about the TRP channels in osteoblasts. Here, we inventoried the gene expression and addressed some roles of the TRP channels in various osteoblast-like cells. The transcripts of canonical TRP (TRPC) channels were revealed for TRPC1, TRPC3, TRPC4 and TRPC6 in human MG-63, SaOS and U2 OS osteoblasts while transcripts for TRPC2, TRPC4, TRPC6 and TRPC7 were observed in the murine MC3T3 osteoblasts. PCR products were shown for the melastatin-related TRP (TRPM) channels TRPM4, TRPM6, TRPM7 and TRPM8 in all cell lines. The TRPM1 was specifically expressed by murine MC3T3 cells while the TRPM3 transcripts were revealed solely in human osteoblast-like cells. Transcripts for TRPV2 and TRPV4 were shown in osteoblastic cells. By interfering RNA approaches, the TRPC1 channels in osteoblasts were shown to be responsible for the capacitative calcium entry (CCE) and for the stimulation of cell proliferation by platelet-derived growth factor. On the other hand, interfering RNA-mediated abrogation of the expression of TRPM7, known as calcium and magnesium channels, resulted in the reduction of both basal and growth factor-stimulated osteoblastic cell proliferation. Our results provide the first complete reference for the gene expression of TRP channels in osteoblasts and point to their importance in cell proliferation.
骨量的维持依赖于成骨细胞充足的增殖、分化、基质蛋白分泌以及凋亡速率。尽管越来越多的证据表明瞬时受体电位（TRP）通道在众多细胞功能中发挥重要作用，但关于成骨细胞中TRP通道的信息有限。在此，我们梳理了TRP通道在各种成骨样细胞中的基因表达情况并探讨了其一些作用。在人MG - 63、SaOS和U2 OS成骨细胞中发现了经典TRP（TRPC）通道TRPC1、TRPC3、TRPC4和TRPC6的转录本，而在小鼠MC3T3成骨细胞中观察到了TRPC2、TRPC4、TRPC6和TRPC7的转录本。在所有细胞系中均显示出与褪黑素相关的TRP（TRPM）通道TRPM4、TRPM6、TRPM7和TRPM8的PCR产物。TRPM1由小鼠MC3T3细胞特异性表达，而TRPM3转录本仅在人成骨样细胞中被发现。在成骨细胞中显示出TRPV2和TRPV4的转录本。通过RNA干扰方法，成骨细胞中的TRPC1通道被证明负责容量性钙内流（CCE）以及血小板衍生生长因子对细胞增殖的刺激。另一方面，RNA干扰介导的钙镁通道TRPM7表达的消除导致基础和成骨细胞生长因子刺激的增殖均减少。我们的结果为成骨细胞中TRP通道的基因表达提供了首个完整参考，并指出了它们在细胞增殖中的重要性。
