Décave Emmanuel, Rieu Didier, Dalous Jerémie, Fache Sébastien, Brechet Yves, Fourcade Bertrand, Satre Michel, Bruckert Franz
Laboratoire de Biochimie et Biophysique des Systèmes Intégrés, Département Réponse et Dynamique Cellulaires, CEA-Grenoble, DRDC/BBSI, 17 rue des Martyrs, 38054 Grenoble Cedex 09, France.
J Cell Sci. 2003 Nov 1;116(Pt 21):4331-43. doi: 10.1242/jcs.00726. Epub 2003 Sep 9.
Application of a mild hydrodynamic shear stress to Dicytostelium discoideum cells, unable to detach cells passively from the substrate, triggers a cellular response consisting of steady membrane peeling at the rear edge of the cell and periodic cell contact extensions at its front edge. Both processes require an active actin cytoskeleton. The cell movement induced by the hydrodynamic forces is very similar to amoeboid cell motion during chemotaxis, as for its kinematic parameters and for the involvement of phosphatidylinositol(3,4,5)-trisphosphate internal gradient to maintain cell polarity. Inhibition of phosphoinositide 3-kinases by LY294002 randomizes the orientation of cell movement with respect to the flow without modifying cell speed. Two independent signaling pathways are, therefore, induced in D. discoideum in response to external forces. The first increases the frequency of pseudopodium extension, whereas the second redirects the actin cytoskeleton polymerization machinery to the edge opposite to the stressed side of the cell.
对盘基网柄菌细胞施加温和的流体动力剪切应力，这种应力无法使细胞被动地从底物上脱离，会引发一种细胞反应，该反应包括细胞后缘稳定的膜剥离以及前缘周期性的细胞接触延伸。这两个过程都需要活跃的肌动蛋白细胞骨架。由流体动力诱导的细胞运动与趋化作用期间的变形虫样细胞运动非常相似，在运动学参数以及磷脂酰肌醇(3,4,5)-三磷酸内部梯度参与维持细胞极性方面都很相似。LY294002对磷酸肌醇3激酶的抑制作用会使细胞运动方向相对于流动随机化，而不会改变细胞速度。因此，盘基网柄菌会响应外力诱导出两条独立的信号通路。第一条通路会增加伪足延伸的频率，而第二条通路会将肌动蛋白细胞骨架聚合机制重定向到细胞受应力一侧相对的边缘。
