Muramatsu Hiroshi, Naka Masahiro, Ito Sae, Kawamura Maki
School of Bioscience and Biotechnology, Tokyo University of Technology, 1401-1 Katakura, Hachioji, Tokyo 192-0982, Japan.
Heliyon. 2023 Sep 11;9(9):e20047. doi: 10.1016/j.heliyon.2023.e20047. eCollection 2023 Sep.
The morphological response of HepG2 cells to mitomycin C was analyzed using a multichannel quartz crystal microbalance system equipped with a home-built movable microscope that enables the simultaneous acquisition of cell images and measurements of eight-channel quartz crystal microbalance. After 24 h of cell seeding, mitomycin C was injected into the culture medium. During the attachment process, the resonant frequency decreased, and the curves fitted well with the first-order lag response. Analysis of the response to mitomycin C revealed that the resonant frequency response curves varied with mitomycin C concentration. When the mitomycin C concentration was <10 μmol L, the delay time was observed before the increase in resonant frequency. When the mitomycin C concentration was extremely low, an additional decrease in resonant frequency was observed in the middle of the delay time that fitted well with the cumulative log-normal distribution curve. The resonant frequency response curves after the delay time fitted well with the cumulative log-normal distribution curves. The delay time and mean cumulative log-normal distribution time for the increase in resonant frequency correlated with the mitomycin C concentration; however, the mean time for the additional decrease in the resonant frequency did not show a statistically significant difference as a function of mitomycin C concentration. For mitomycin C concentrations of >20 μmol L, the response to the change in resonant frequency was rapid, and the response curves fitted well with the first-order lag response. The first-order lag response indicates that the response occurred simultaneously for all cells. The results showed that the time constant was independent of the tested mitomycin C concentration between 20 and 100 μmol L. These results suggested that different cell death processes occurred by mitomycin C. The findings of this study suggest that the system can be used to investigate cell death in adherent cells.
使用配备自制可移动显微镜的多通道石英晶体微天平系统分析HepG2细胞对丝裂霉素C的形态学反应，该系统能够同时采集细胞图像并测量八通道石英晶体微天平。细胞接种24小时后，将丝裂霉素C注入培养基中。在细胞附着过程中，共振频率降低，曲线与一阶滞后响应拟合良好。对丝裂霉素C反应的分析表明，共振频率响应曲线随丝裂霉素C浓度而变化。当丝裂霉素C浓度<10μmol/L时，在共振频率增加之前观察到延迟时间。当丝裂霉素C浓度极低时，在延迟时间中间观察到共振频率的额外降低，这与累积对数正态分布曲线拟合良好。延迟时间后的共振频率响应曲线与累积对数正态分布曲线拟合良好。共振频率增加的延迟时间和平均累积对数正态分布时间与丝裂霉素C浓度相关；然而，共振频率额外降低的平均时间作为丝裂霉素C浓度的函数未显示出统计学上的显著差异。对于丝裂霉素C浓度>20μmol/L，对共振频率变化的反应迅速，反应曲线与一阶滞后响应拟合良好。一阶滞后响应表明所有细胞同时发生反应。结果表明，时间常数在20至100μmol/L之间与测试的丝裂霉素C浓度无关。这些结果表明丝裂霉素C发生了不同的细胞死亡过程。本研究结果表明该系统可用于研究贴壁细胞的细胞死亡。
