Abstract
Cell adhesion is important to cell function. Focal adhesions (FAs) are large protein complexes organized at the basal surface of cells, which physically connect the extracellular matrix to the cytoskeleton and maintain the form of the cell. However, how the focal adhesion morphology change during cell adhesion to the extracellular matrix is still not clear yet. In this study, we used a MC3T3-E1 cell line as the test model. We plate the cells whose cycle had been synchronized by serum starvation on glass bottom dishes and cultured them for 10, 20, 30, 40, 50 min, and 1, 3, 6, 9, 12, 15, 18, 21, 24 h, then stained the F-actin, vinculin and nucleus and observed their change of morphology. We measured the cell area A_<cell>, number of FAs per cell N_<FA>, mean area of each FA A_<FA>, total area of FA per cell TA_<FA>. We grouped the FAs into three categories (small, middle, large) depending on their area and calculated their ratios to N_<FA>. The results revealed that A_<cell> increased generally, and these parameters about FA were simply changed until the cell area after cultured for about 1h. However they had different time course changes afterwards, especially around 3-12 h and 21-24 h after plating. These changes might indicate that dynamics of FAs is influenced by cell cycle.
