ATP- and gap junction-dependent intercellular calcium signaling in osteoblastic cells.
ATP- and gap junction-dependent intercellular calcium signaling in osteoblastic cells.
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DOI：
10.1083/jcb.139.2.497
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发表时间：
1997-10-20
期刊：
影响因子：
--
通讯作者：
Steinberg TH
中科院分区：
文献类型：
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作者：
Jorgensen NR;Geist ST;Civitelli R;Steinberg TH
许多细胞通过在细胞间传递细胞内钙的升高来协调它们的活动。在非兴奋性细胞中，目前有两种细胞间钙波传播模型，这两种模型都涉及三磷酸肌醇（IP 3）敏感的细胞内钙库的释放。在一个模型中，IP 3穿过间隙连接并启动邻近细胞中细胞内钙储存的释放。另外，钙波可能不是由缝隙连接通讯介导的，而是由P2嘌呤能受体上分泌的ATP的自分泌活性介导的。我们研究了机械诱导的钙波在两个大鼠骨肉瘤细胞系，不同的差距连接蛋白，他们表达，在他们的能力，通过显微注射染料从细胞到细胞，并在他们的表达P2 Y2（P2 U）嘌呤能受体。表达差距连接蛋白连接蛋白43（Cx43）的ROS 17/2.8细胞是良好的染料偶联的，并且缺乏P2 U受体，其传递不需要释放细胞内钙储存的缓慢间隙连接依赖性钙波。UMR 106-01细胞主要表达差距连接蛋白连接蛋白45（Cx45），染料偶联较差，并表达P2 U受体;它们传播快速钙波，需要释放细胞内钙储存和激活P2 U嘌呤能受体，但不需要间隙连接通讯。ROS/P2 U和UMR/Cx43转染细胞表达两种类型的钙波。在仓鼠气管上皮细胞中也观察到非缝隙连接依赖的、ATP依赖的细胞间钙波。这些研究表明，P2 U嘌呤能受体的激活可以传播细胞间钙，并描述了一种新的Cx43依赖性机制的钙波传播，不需要释放细胞内的钙储存的IP 3。这些研究表明，由Cx43或Cx45介导的间隙连接通讯不允许IP 3足够好地通过以引起邻近细胞中细胞内钙储存的释放。
Many cells coordinate their activities by transmitting rises in intracellular calcium from cell to cell. In nonexcitable cells, there are currently two models for intercellular calcium wave propagation, both of which involve release of inositol trisphosphate (IP3)- sensitive intracellular calcium stores. In one model, IP3 traverses gap junctions and initiates the release of intracellular calcium stores in neighboring cells. Alternatively, calcium waves may be mediated not by gap junctional communication, but rather by autocrine activity of secreted ATP on P2 purinergic receptors. We studied mechanically induced calcium waves in two rat osteosarcoma cell lines that differ in the gap junction proteins they express, in their ability to pass microinjected dye from cell to cell, and in their expression of P2Y2 (P2U) purinergic receptors. ROS 17/2.8 cells, which express the gap junction protein connexin43 (Cx43), are well dye coupled, and lack P2U receptors, transmitted slow gap junction-dependent calcium waves that did not require release of intracellular calcium stores. UMR 106-01 cells predominantly express the gap junction protein connexin 45 (Cx45), are poorly dye coupled, and express P2U receptors; they propagated fast calcium waves that required release of intracellular calcium stores and activation of P2U purinergic receptors, but not gap junctional communication. ROS/P2U transfectants and UMR/Cx43 transfectants expressed both types of calcium waves. Gap junction–independent, ATP-dependent intercellular calcium waves were also seen in hamster tracheal epithelia cells. These studies demonstrate that activation of P2U purinergic receptors can propagate intercellular calcium, and describe a novel Cx43-dependent mechanism for calcium wave propagation that does not require release of intracellular calcium stores by IP3. These studies suggest that gap junction communication mediated by either Cx43 or Cx45 does not allow passage of IP3 well enough to elicit release of intracellular calcium stores in neighboring cells.