Schumacher Kristopher R, Popel Aleksander S, Anvari Bahman, Brownell William E, Spector Alexander A
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Oct;80(4 Pt 1):041905. doi: 10.1103/PhysRevE.80.041905. Epub 2009 Oct 6.
Tethers are thin membrane tubes that can be formed when relatively small and localized forces are applied to cellular membranes and lipid bilayers. Tether pulling experiments have been used to better understand the fine membrane properties. These include the interaction between the plasma membrane and the underlying cytoskeleton, which is an important factor affecting membrane mechanics. We use a computational method aimed at the interpretation and design of tether pulling experiments in cells with a strong membrane-cytoskeleton attachment. In our model, we take into account the detailed information in the topology of bonds connecting the plasma membrane and the cytoskeleton. We compute the force-dependent piecewise membrane deflection and bending as well as modes of stored energy in three major regions of the system: body of the tether, membrane-cytoskeleton attachment zone, and the transition zone between the two. We apply our method to three cells: cochlear outer hair cells (OHCs), human embryonic kidney (HEK) cells, and Chinese hamster ovary (CHO) cells. OHCs have a special system of pillars connecting the membrane and the cytoskeleton, and HEK and CHO cells have the membrane-cytoskeleton adhesion arrangement via bonds (e.g., PIP2), which is common to many other cells. We also present a validation of our model by using experimental data on CHO and HEK cells. The proposed method can be an effective tool in the analyses of experiments to probe the properties of cellular membranes.
系链是一种薄的膜管，当相对较小的局部力作用于细胞膜和脂质双层时就会形成。系链拉伸实验已被用于更好地理解精细的膜特性。这些特性包括质膜与下层细胞骨架之间的相互作用，这是影响膜力学的一个重要因素。我们使用一种计算方法，旨在解释和设计在具有强膜 - 细胞骨架附着的细胞中的系链拉伸实验。在我们的模型中，我们考虑了连接质膜和细胞骨架的键的拓扑结构中的详细信息。我们计算了系统三个主要区域中力依赖的分段膜偏转和弯曲以及储能模式：系链主体区域、膜 - 细胞骨架附着区域以及两者之间的过渡区域。我们将我们的方法应用于三种细胞：耳蜗外毛细胞（OHCs）、人胚肾（HEK）细胞和中国仓鼠卵巢（CHO）细胞。OHCs 具有连接膜和细胞骨架的特殊柱状系统，而 HEK 和 CHO 细胞通过键（例如磷脂酰肌醇 - 4,5 - 二磷酸，PIP2）具有膜 - 细胞骨架粘附排列，这在许多其他细胞中很常见。我们还通过使用 CHO 和 HEK 细胞的实验数据对我们的模型进行了验证。所提出的方法可以成为分析探测细胞膜特性实验的有效工具。
