Ajubi N E, Klein-Nulend J, Nijweide P J, Vrijheid-Lammers T, Alblas M J, Burger E H
Department of Oral Cell Biology, ACTA-Vrije Universiteit, Amsterdam, The Netherlands.
Biochem Biophys Res Commun. 1996 Aug 5;225(1):62-8. doi: 10.1006/bbrc.1996.1131.
It has been postulated that the transduction of mechanical stress signals to bone cells occurs via loading-dependent flow of interstitial fluid through the lacuno-canalicular network of bone. We have shown earlier that chicken osteocytes release enhanced amounts of prostaglandin E2 after 1 h treatment with pulsating fluid flow (PFF, 0.5 +/- 0.02 Pa, 5 Hz). Here we study the acute response to PFF on three cell populations derived from fetal chick calvariae, namely periosteal fibroblasts (PF), an osteoblast and osteocyte containing population (OBmix), and osteocytes (OCY), and the involvement of the actin-cytoskeleton in this process. All three cell populations rapidly (OCY: within 5 min, OBmix, PF: within 10 min) increased their release of prostaglandins E2 and I2 in response to PFF, but the response by OCY was 2-4 times higher than that by OBmix or PF. Disruption of the actin-cytoskeleton by cytochalasin B completely abolished the response. We conclude that osteocytes are more sensitive to fluid shear stress than immature bone cells, and that the actin-cytoskeleton is involved in the response to fluid flow.
据推测，机械应力信号向骨细胞的转导是通过间隙液在骨的腔隙-小管网络中依赖负荷的流动来实现的。我们之前已经表明，用脉动流体流（PFF，0.5±0.02 Pa，5 Hz）处理1小时后，鸡骨细胞释放的前列腺素E2量会增加。在此，我们研究了源自胎鸡颅骨的三种细胞群体，即骨膜成纤维细胞（PF）、含成骨细胞和骨细胞的群体（OBmix）以及骨细胞（OCY）对PFF的急性反应，以及肌动蛋白细胞骨架在此过程中的作用。所有这三种细胞群体对PFF的反应均迅速（OCY：在5分钟内，OBmix、PF：在10分钟内）增加了前列腺素E2和I2的释放，但OCY的反应比OBmix或PF高2 - 4倍。用细胞松弛素B破坏肌动蛋白细胞骨架完全消除了这种反应。我们得出结论，骨细胞比未成熟骨细胞对流体剪切应力更敏感，并且肌动蛋白细胞骨架参与了对流体流动的反应。
