Non-equilibration of hydrostatic pressure in blebbing cells
Non-equilibration of hydrostatic pressure in blebbing cells
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DOI：
10.1038/nature03550
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发表时间：
2005-05-19
期刊：
影响因子：
64.8
通讯作者：
Mitchison, TJ
中科院分区：
文献类型：
--
作者：
Charras, GT;Yarrow, JC;Mitchison, TJ
目前动物细胞突出运动的模型主要集中在基于细胞骨架的机制上，其中局部突出是由肌动蛋白生物化学的局部调节驱动的（1-3）。在植物和真菌中，突出主要是由静水压力驱动的（4-6）。为了使静水压力驱动动物细胞中的局部突起（7,8），它必须受到局部调节，但目前的模型将细胞质视为不可压缩的粘弹性连续体(9)或粘性液体（10），要求整个细胞的静水压力基本上是瞬间平衡的。这里，我们使用细胞泡作为细胞质中局部压力的报告者。当我们用皮质松弛药物局部灌注起泡细胞以消除一侧的压力时，未处理的一侧继续起泡，这意味着在大约10 μ m和10 s的尺度上压力不平衡。我们可以通过考虑细胞质是一个被细胞质溶胶浸润的收缩的、弹性的网络来解释压力的局域化。流体相对于网络的运动在压力场中产生空间上的非均匀瞬态，可以用孔隙弹性的框架来描述（11,12）。
Current models for protrusive motility in animal cells focus on cytoskeleton-based mechanisms, where localized protrusion is driven by local regulation of actin biochemistry(1-3). In plants and fungi, protrusion is driven primarily by hydrostatic pressure(4-6). For hydrostatic pressure to drive localized protrusion in animal cells(7,8), it would have to be locally regulated, but current models treating cytoplasm as an incompressible viscoelastic continuum(9) or viscous liquid(10) require that hydrostatic pressure equilibrates essentially instantaneously over the whole cell. Here, we use cell blebs as reporters of local pressure in the cytoplasm. When we locally perfuse blebbing cells with cortex-relaxing drugs to dissipate pressure on one side, blebbing continues on the untreated side, implying non-equilibration of pressure on scales of approximately 10 mu m and 10 s. We can account for localization of pressure by considering the cytoplasm as a contractile, elastic network infiltrated by cytosol. Motion of the fluid relative to the network generates spatially heterogeneous transients in the pressure field, and can be described in the framework of poroelasticity(11,12).