Wang Xianmeng, Li Na, Zhang Zhengyao, Qin Kairong, Zhang Hangyu, Shao Shuai, Liu Bo
School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China.
Liaoning Key Laboratory of Integrated Circuit and Biomedical Electronic System, Dalian University of Technology, Dalian 116024, China.
Biology (Basel). 2023 Jun 20;12(6):889. doi: 10.3390/biology12060889.
The extracellular stress signal transmits along the cell membrane-cytoskeleton-focal adhesions (FAs) complex, regulating the cell function through membrane tension. However, the mechanism of the complex regulating membrane tension is still unclear. This study designed polydimethylsiloxane stamps with specific shapes to change the actin filaments' arrangement and FAs' distribution artificially in live cells, visualized the membrane tension in real time, and introduced the concept of information entropy to describe the order degree of the actin filaments and plasma membrane tension. The results showed that the actin filaments' arrangement and FAs' distribution in the patterned cells were changed significantly. The hypertonic solution resulted in the plasma membrane tension of the pattern cell changing more evenly and slowly in the zone rich in cytoskeletal filaments than in the zone lacking filaments. In addition, the membrane tension changed less in the adhesive area than in the non-adhesive area when destroying the cytoskeletal microfilaments. This suggested that patterned cells accumulated more actin filaments in the zone where FAs were difficult to generate to maintain the stability of the overall membrane tension. The actin filaments act as shock absorbers to cushion the alternation in membrane tension without changing the final value of membrane tension.
细胞外应激信号沿着细胞膜-细胞骨架-黏着斑（FAs）复合体进行传递，通过膜张力调节细胞功能。然而，该复合体调节膜张力的机制仍不清楚。本研究设计了具有特定形状的聚二甲基硅氧烷压模，以在活细胞中人为改变肌动蛋白丝的排列和FAs的分布，实时可视化膜张力，并引入信息熵的概念来描述肌动蛋白丝的有序程度和质膜张力。结果表明，图案化细胞中肌动蛋白丝的排列和FAs的分布发生了显著变化。高渗溶液导致图案化细胞的质膜张力在富含细胞骨架丝的区域比在缺乏丝的区域变化更均匀、更缓慢。此外，破坏细胞骨架微丝时，黏附区域的膜张力变化比非黏附区域小。这表明图案化细胞在难以产生FAs的区域积累了更多的肌动蛋白丝，以维持整体膜张力的稳定性。肌动蛋白丝起到减震器的作用，在不改变膜张力最终值的情况下缓冲膜张力的变化。
