Department of Functional Molecular Biology, Graduate School of Medicine, Yamaguchi University, Yamaguchi, 753-8512, Japan.
Sci Rep. 2017 Oct 11;7(1):12970. doi: 10.1038/s41598-017-13438-5.
The role of cell membrane dynamics in cell migration is unclear. To examine whether total cell surface area changes are required for cell migration, Dictyostelium cells were flattened by agar-overlay. Scanning electron microscopy demonstrated that flattened migrating cells have no membrane reservoirs such as projections and membrane folds. Similarly, optical sectioning fluorescence microscopy showed that the cell surface area does not change during migration. Interestingly, staining of the cell membrane with a fluorescent lipid analogue demonstrated that the turnover rate of cell membrane is closely related to the cell migration velocity. Next, to clarify the mechanism of cell membrane circulation, local photobleaching was separately performed on the dorsal and ventral cell membranes of rapidly moving cells. The bleached zones on both sides moved rearward relative to the cell. Thus, the cell membrane moves in a fountain-like fashion, accompanied by a high membrane turnover rate and actively contributing to cell migration.
细胞膜动力学在细胞迁移中的作用尚不清楚。为了研究细胞迁移是否需要改变细胞膜总面积，我们通过琼脂覆盖将变形虫细胞压平。扫描电子显微镜显示，压平的迁移细胞没有膜储备库，如突起和膜褶皱。同样，光学切片荧光显微镜显示，细胞膜面积在迁移过程中不会发生变化。有趣的是，用荧光脂质类似物对细胞膜进行染色表明，细胞膜的周转率与细胞迁移速度密切相关。接下来，为了阐明细胞膜循环的机制，我们分别对快速移动细胞的背侧和腹侧细胞膜进行局部光漂白。两侧的漂白区域相对于细胞向后移动。因此，细胞膜以喷泉状的方式移动，伴随着高的膜周转率，并积极促进细胞迁移。
