Filamin-A and rheological properties of cultured melanoma cells
Filamin-A and rheological properties of cultured melanoma cells
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DOI：
10.1529/biophysj.105.061267
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发表时间：
2006-03-01
影响因子：
3.4
通讯作者：
Fredberg, JJ
中科院分区：
文献类型：
--
作者：
Coughlin, MF;Puig-de-Morales, M;Fredberg, JJ
在这里，我们报告了培养的表达 hsFLNa（细丝蛋白-A）（FIL+）和 hsFLNa 缺陷（FIL-）黑色素瘤细胞的流变学特性。在广泛的探测频率下使用磁扭转细胞术，并针对皮质或更深层的细胞骨架结构，我们发现 FIL+ 与 FIL- 细胞的硬度差异非常小。当通过深层细胞骨架结构探测时，FIL+细胞最多比FIL-细胞硬30%，而当通过更外围的细胞骨架结构探测时，FIL-细胞除了频率非常高外没有什么不同。 FIL- 细胞的损耗角正切（以有效细胞骨架温度表示）总体上大于 FIL+ 细胞，但这些差异很小，表明 FIL+ 细胞仅稍微接近固态。为了量化细胞骨架重塑，我们测量了与皮质细胞骨架结构结合的珠子的自发运动，发现 FIL+ 与 FIL- 细胞没有差异。尽管 FIL+ 和 FIL- 细胞之间的机械差异在皮质和深层结构中都很明显，但这些差异远小于基于纯化肌动蛋白流变学测量的预期。核纤层蛋白解决方案。这些发现并不排除有重要贡献。层粘连蛋白对皮质细胞骨架的机械性能，但表明有影响。皮质中的核纤层蛋白不影响此处使用的探针的长度尺度。这些发现似乎排除了任何重要的贡献。然而，核纤层蛋白对细胞质的大部分机械特性有影响。虽然。核纤层蛋白存在于细胞质中，它可能是无活性的，与其他交联剂相比，其机械效应可能很小，或者基质的机械性能可能由细胞骨架预应力的压倒性作用主导。
Here we report the rheological properties of cultured hsFLNa (filamin-A)-expressing ( FIL+) and hsFLNa-deficient ( FIL-) melanoma cells. Using magnetic twisting cytometry over a wide range of probing frequencies, and targeting either cortical or deeper cytoskeletal structures, we found that differences in stiffness of FIL+ versus FIL- cells were remarkably small. When probed through deep cytoskeletal structures, FIL+ cells were, at most, 30% stiffer than FIL- cells, whereas when probed through more peripheral cytoskeletal structures FIL- cells were not different except at very high frequencies. The loss tangent, expressed as an effective cytoskeletal temperature, was systematically greater in FIL- than FIL+ cells, but these differences were small and showed that the FIL+ cells were only slightly closer to a solidlike state. To quantify cytoskeletal remodeling, we measured spontaneous motions of beads bound to cortical cytoskeletal structures and found no difference in FIL+ versus FIL- cells. Although mechanical differences between FIL+ and FIL- cells were evident both in cortical and deeper structures, these differences were far smaller than expected based on measurements of the rheology of purified actin. lamin solutions. These findings do not rule out an important contribution of. lamin to the mechanical properties of the cortical cytoskeleton, but suggest that effects of. lamin in the cortex are not exerted on the length scale of the probe used here. These findings would appear to rule out any important contribution of. lamin to the bulk mechanical properties of the cytoplasm, however. Although. lamin is present in the cytoplasm, it may be inactive, its mechanical effects may be small compared with other crosslinkers, or mechanical properties of the matrix may be dominated by an overriding role of cytoskeletal prestress.