Activation of L-type calcium channels is required for gap junction-mediated intercellular calcium signaling in osteoblastic cells
Activation of L-type calcium channels is required for gap junction-mediated intercellular calcium signaling in osteoblastic cells
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DOI：
10.1074/jbc.m205880200
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发表时间：
2003-02-07
影响因子：
4.8
通讯作者：
Steinberg, TH
中科院分区：
文献类型：
--
作者：
Jorgensen, NR;Teilmann, SC;Steinberg, TH
成骨细胞中机械诱导的细胞间钙波（ICW）的传播既通过细胞外核苷酸激活P2 Y（嘌呤能）受体，导致“快速”ICW，也通过表达连接蛋白43（Cx43）的细胞中的间隙连接通讯，导致“缓慢”ICW。人成骨细胞通过这两种机制传递细胞间钙信号。在目前的研究中，我们已经研究了成骨细胞中慢间隙连接依赖性ICW的机制。在ROS大鼠成骨细胞中，间隙连接依赖性ICW被细胞外钙的去除、细胞外高钾引起的质膜去极化和L型电压操纵性钙通道抑制剂硝苯地平抑制。相反，所有这些治疗增强了P2受体介导的ICW在UMR大鼠成骨细胞中的扩散。使用转染表达Cx43的UMR细胞（UMR/Cx43），我们证实了ICW的硝苯地平敏感性需要Cx43的表达。在人成骨细胞中，间隙连接依赖性ICW也需要L型钙通道的激活和细胞外钙的内流。
The propagation of mechanically induced intercellular calcium waves (ICW) among osteoblastic cells occurs both by activation of P2Y (purinergic) receptors by extracellular nucleotides, resulting in "fast" ICW, and by gap junctional communication in cells that express connexin43 (Cx43), resulting in "slow" ICW. Human osteoblastic cells transmit intercellular calcium signals by both of these mechanisms. In the current studies we have examined the mechanism of slow gap junction-dependent ICW in osteoblastic cells. In ROS rat osteoblastic cells, gap junction-dependent ICW were inhibited by removal of extracellular calcium, plasma membrane depolarization by high extracellular potassium, and the L-type voltage-operated calcium channel inhibitor, nifedipine. In contrast, all these treatments enhanced the spread of P2 receptor-mediated ICW in UMR rat osteoblastic cells. Using UMR cells transfected to express Cx43 (UMR/Cx43) we confirmed that nifedipine sensitivity of ICW required Cx43 expression. In human osteoblastic cells, gap junction-dependent ICW also required activation of L-type calcium channels and influx of extracellular calcium.