A concept for the physiological stiffness of a living cell

多年前，为分子“细胞膜电位概念”奠定了基础，彻底改变了细胞研究，并导致了生物科学的巨大进步。与电细胞膜电位类似，细胞硬度是表征活细胞的另一个基本生理参数。至少有三层，即糖萼、质膜和膜下细胞骨架决定了细胞的硬度。我们假设，这三个层的单独实验检查可能会导致这个生理关键参数的一般定义，可能适用于任何活细胞。该提案的技术基础形成了一种混合仪器，将原子力显微镜与荧光显微镜相结合。作为生物模型，我们将使用最适合这种测量的活血管内皮细胞。它们有一个突出的糖萼，一个功能良好的质膜和一个动态活跃的膜下细胞骨架。计划使用各种实验方法逐层表征，所述实验方法的范围从选择性去除糖萼、特定膜蛋白的表达到改变膜下细胞层的粘度。该项目将为活细胞机械刚度的第一个生理概念铺平道路。

Setting the basis for a molecular “concept of the electrical cell membrane potential” many years ago revolutionized cell research and led to an enormous progress in biosciences. Similar as the electrical cell membrane potential, cell stiffness is another fundamental physiological parameter that characterizes a living cell. At least three layers, the glycocalyx, the plasma membrane and the submembranous cytoskeleton determine the cell stiffness. We assume that the separate experimental examination of these three layers could lead to a general definition of this physiological key parameter that may be applicable to any living cell. The technical basis of this proposal forms a hybrid instrument that unifies atomic force microscopy with fluorescence microscopy. As a biological model we will use living vascular endothelial cells that are most suitable for such measurements. They have a prominent glycocalyx, a functionally well characterized plasma membrane and a dynamically active submembraneous cytoskeleton. It is planned to characterize layer by layer using various experimental methods that range from the selective removal of the glycocalyx, the expression of specific membrane proteins to varying the viscosity of the submembraneous cell layer. The project should pave the way for a first physiological concept on mechanical stiffness of living cells.