Pajic-Lijakovic Ivana, Milivojevic Milan
Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120, Belgrade, Serbia,
J Membr Biol. 2015 Apr;248(2):337-47. doi: 10.1007/s00232-015-9775-z. Epub 2015 Feb 7.
Studies of cell membrane fluctuations under micro rheological measurements suggest that coupling between the lipid bilayer and the actin cortex can affects viscoelastic behavior of the single cell membranes. Coupling induces anomalous nature of energy dissipation during rearrangement of both: the actin cortex and the lipid bilayer. The actin cortex ability to rearrange for various cell types: erythrocytes, Jurkat cells, fibroblasts, epithelial lung cells, and muscle cells based on experimental data for storage and loss moduli versus angular velocity are considered. The cortex of softer cells such as erythrocytes, Jurkat cells, and fibroblasts has the ability to rearrange at low angular velocities which is quantified by their rearrangement time and the average size of the cortex micro domains. The rearrangement time of the cortex for Jurkat cells and fibroblasts is at the order of magnitude higher than that for erythrocytes, i.e., 2.70-7.53 s. The average size of the cortex micro domains for erythrocytes varied from 3.0 to 5.3 μm, for Jurkat cells is ~0.20-0.22 μm and for fibroblasts is ~36 nm. Lower size of the micro domains and higher rearrangement time indicate the stiffer cortex structure. The cortex rearrangement for stiffer cells such as epithelial lung cells and muscle cells has never been observed.
微流变测量下的细胞膜波动研究表明，脂质双层与肌动蛋白皮层之间的耦合会影响单细胞膜的粘弹性行为。耦合会在肌动蛋白皮层和脂质双层重新排列过程中引发能量耗散的异常特性。基于储能模量和损耗模量与角速度的实验数据，考虑了不同细胞类型（红细胞、 Jurkat细胞、成纤维细胞、肺上皮细胞和肌肉细胞）中肌动蛋白皮层的重新排列能力。诸如红细胞、 Jurkat细胞和成纤维细胞等较软细胞的皮层能够在低角速度下重新排列，这通过它们的重新排列时间和皮层微区的平均大小来量化。 Jurkat细胞和成纤维细胞皮层的重新排列时间比红细胞的高出一个数量级，即2.70 - 7.53秒。红细胞皮层微区的平均大小在3.0至5.3μm之间，Jurkat细胞约为0.20 - 0.22μm，成纤维细胞约为36nm。微区尺寸越小且重新排列时间越长，表明皮层结构越硬。从未观察到诸如肺上皮细胞和肌肉细胞等较硬细胞的皮层重新排列。
