Human osteoblastic cells propagate intercellular calcium signals by two different mechanisms
Human osteoblastic cells propagate intercellular calcium signals by two different mechanisms
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DOI：
10.1359/jbmr.2000.15.6.1024
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发表时间：
2000-06-01
影响因子：
6.2
通讯作者：
Steinberg, TH
中科院分区：
文献类型：
--
作者：
Jorgensen, NR;Henriksen, Z;Steinberg, TH
有效的骨重建需要成骨细胞协调骨基质沉积，这可以通过可溶性介质或通过直接的细胞间通讯发生。我们已发现大鼠成骨细胞系通过两种机制来协调细胞间的钙信号传递：P2(嘌呤能)受体的自分泌激活导致细胞内钙储存的释放，以及缝隙连接介导的通讯导致细胞外钙内流。在目前的工作中，我们询问了人成骨细胞(HOB)是否能够机械地诱导细胞间钙信号，如果是，通过什么机制。在机械刺激下，人成骨细胞传播快速的细胞间钙波，这需要激活P2受体和释放细胞内的钙库，但不需要钙内流或缝隙连接通讯。在快速的细胞内钙波被阻断后，我们观察到依赖于缝隙连接通讯和细胞外钙内流的较慢的钙波。这些结果表明，人成骨细胞可以通过两种明显不同的机制将钙信号从细胞传播到细胞，提示这两种途径可能在协调成骨细胞功能方面起着不同的作用。
Effective bone remodeling requires the coordination of bone matrix deposition by osteoblastic cells, which may occur via soluble mediators or via direct intercellular communication. We have previously identified two mechanisms by which rat osteoblastic cell lines coordinate calcium signaling among cells: autocrine activation of P2 (purinergic) receptors leading to release of intracellular calcium stores, and gap junction-mediated communication resulting in influx of extracellular calcium. In the current work we asked whether human osteoblastic cells (HOB) were capable of mechanically induced intercellular calcium signaling, and if so, by which mechanisms. Upon mechanical stimulation, human osteoblasts propagated fast intercellular calcium waves, which required activation of P2 receptors and release of intracellular calcium stores but did not require calcium influx or gap junctional communication. After the fast intercellular calcium waves were blocked, we observed slower calcium waves that were dependent on gap junctional communication and influx of extracellular calcium. These results show that human osteoblastic cells can propagate calcium signals from cell to cell by two markedly different mechanisms and suggest that these two pathways may serve different purposes in coordinating osteoblast functions.