Life and times of a cellular bleb
Life and times of a cellular bleb
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DOI：
10.1529/biophysj.107.113605
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发表时间：
2008-03-01
影响因子：
3.4
通讯作者：
Mahadevan, L.
中科院分区：
文献类型：
--
作者：
Charras, Guillaume T.;Coughlin, Margaret;Mahadevan, L.
水泡是在许多生理情况下发生的球形细胞突起。两个不同的阶段，使生活的一个水泡，其中每一个都有自己的生物学和物理学：扩张，持续时间类似于30秒，和收缩，持续时间类似于2分钟。我们调查这些阶段使用光学显微镜和简单的理论概念，寻求信息水泡本身，并在一般的细胞力学。我们表明，水泡成核取决于压力，膜皮质粘附能，和膜张力，并测试实验。通过脂质的大量流动和经由泪液的形成和传播从细胞皮层分层的组合发生水泡生长。在极端的情况下，这会引起细胞周围的行波，称为“马戏团运动”。“当生长停滞时，肌动蛋白皮质在水泡膜下重新形成，并在肌球蛋白II的驱动下开始收缩。使用闪烁光谱，我们发现，收回水泡比扩大水泡，增加完全由新形成的皮质肌动蛋白网格的属性解释的刚性的五倍。最后，使用人工有核的水泡作为压力传感器，我们表明，在有丝分裂圆形的细胞具有相当大的细胞内压力。
Blebs are spherical cellular protrusions that occur in many physiological situations. Two distinct phases make up the life of a bleb, each of which have their own biology and physics: expansion, which lasts similar to 30 s, and retraction, which lasts similar to 2 min. We investigate these phases using optical microscopy and simple theoretical concepts, seeking information on blebbing itself, and on cytomechanics in general. We show that bleb nucleation depends on pressure, membrane-cortex adhesion energy, and membrane tension, and test this experimentally. Bleb growth occurs through a combination of bulk flow of lipids and delamination from the cell cortex via the formation and propagation of tears. In extreme cases, this can give rise to a traveling wave around the cell periphery, known as "circus movement." When growth stalls, an actin cortex reforms under the bleb membrane, and retraction starts, driven by myosin-II. Using flicker spectroscopy, we find that retracting blebs are fivefold more rigid than expanding blebs, an increase entirely explained by the properties of the newly formed cortical actin mesh. Finally, using artificially nucleated blebs as pressure sensors, we show that cells rounded up in mitosis possess a substantial intracellular pressure.