αVβ3 Integrin ligands enhance volume-sensitive calcium influx in mechanically stretched osteocytes
αVβ3 Integrin ligands enhance volume-sensitive calcium influx in mechanically stretched osteocytes
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DOI：
10.1007/s00774-006-0716-x
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发表时间：
2006-11-01
影响因子：
3.3
通讯作者：
Mikuni-Takagaki, Yuko
中科院分区：
文献类型：
--
作者：
Miyauchi, Akimitsu;Gotoh, Masayuki;Mikuni-Takagaki, Yuko
我们提出，特定的骨细胞-基质相互作用调节体积敏感性钙内流途径，我们已经表明，这是介导的拉伸激活阳离子通道（SA-猫），是必不可少的拉伸激活合成代谢反应在骨。目前的研究测量了低渗肿胀诱导的大鼠骨细胞胞浆钙浓度[Ca 2 +]（i）的增加，发现粘附于不同基质的细胞表现不同。骨桥蛋白和玻连蛋白，结合α（V）β（3）整合素的基质分子，比结合其他整合素的其他基质分子诱导更大的低渗肿胀反应。加入作为可溶性α（V）β（3）配体的echistatin，除了自身诱导[Ca 2 +]（i）的立即增加外，还显著增强了低渗[Ca 2 +]（i）的增加。这些结果有力地支持了骨细胞中的α（V）β（3）整联蛋白信号传导与SA-Cat下游的机械转导中的信号传导相互作用的论点。
We propose that specific osteocyte-matrix interactions regulate the volume-sensitive calcium influx pathway, which we have shown is mediated by stretch-activated cation channels (SA-Cat) and is essential for the stretch-activated anabolic response in bone. The current study measured the hypotonic swelling-induced increase in cytosolic calcium concentration, [Ca2+](i), in rat osteocytes, and found that cells adherent to different matrices behave differently. Osteopontin and vitronectin, matrix molecules that bind the alpha(V)beta(3) integrin, induced larger responses to the hypotonic swelling than other matrix molecules that bind other integrins. Addition of echistatin, which is a soluble alpha(V)beta(3) ligand, significantly enhanced the hypotonic [Ca2+](i) increase in addition to inducing an immediate increase in [Ca2+](i) by itself. These results strongly support the contention that alpha(V)beta(3) integrin signaling in osteocytes interacts with that in mechanotransduction, which is downstream of SA-Cat.