Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824, United States.
Exp Cell Res. 2012 Mar 10;318(5):521-6. doi: 10.1016/j.yexcr.2011.12.003. Epub 2011 Dec 29.
Cell signaling often causes changes in cellular mechanical properties. Knowledge of such changes can ultimately lead to insight into the complex network of cell signaling. In the current study, we employed a combination of atomic force microscopy (AFM) and quartz crystal microbalance with dissipation monitoring (QCM-D) to characterize the mechanical behavior of A431 cells in response to epidermal growth factor receptor (EGFR) signaling. From AFM, which probes the upper portion of an individual cell in a monolayer of cells, we observed increases in energy dissipation, Young's modulus, and hysteresivity. Increases in hysteresivity imply a shift toward a more fluid-like mechanical ordering state in the bodies of the cells. From QCM-D, which probes the basal area of the monolayer of cells collectively, we observed decreases in energy dissipation factor. This result suggests a shift toward a more solid-like state in the basal areas of the cells. The comparative analysis of these results indicates a regionally specific mechanical behavior of the cell in response to EGFR signaling and suggests a correlation between the time-dependent mechanical responses and the dynamic process of EGFR signaling. This study also demonstrates that a combination of AFM and QCM-D is able to provide a more complete and refined mechanical profile of the cells during cell signaling.
细胞信号通常会引起细胞力学性质的变化。对这些变化的了解最终可以深入了解细胞信号的复杂网络。在本研究中，我们采用原子力显微镜（AFM）和石英晶体微天平耗散监测（QCM-D）相结合的方法，研究表皮生长因子受体（EGFR）信号对 A431 细胞力学行为的影响。从 AFM 可以探测到单层细胞中单个细胞的上部，我们观察到能量耗散、杨氏模量和滞后性的增加。滞后性的增加意味着细胞体的力学有序状态向更类似于流体的状态转变。从 QCM-D 可以探测到单层细胞的基底区域，我们观察到能量耗散因子的降低。这一结果表明细胞基底区域向更类似于固体的状态转变。对这些结果的比较分析表明，细胞对 EGFR 信号的反应具有区域性特异性的力学行为，并提示了力学响应的时变与 EGFR 信号动态过程之间的相关性。本研究还表明，AFM 和 QCM-D 的结合能够在细胞信号过程中提供更完整和精细的细胞力学谱。
