Fig. 5

Adhesion to exogenous FN/ECM-coated substrates prevents peripheral membrane detachment and retraction following serum-induced cell contractility. siCNS and siILK cells were grown for 24 h on uncoated (a and b), FN-coated (b) or Col-I-coated (b) plastic dishes. Cells were then starved for 24 h without serum before RhoA-mediated cell contractility was stimulated by adding serum (FBS, 10% final concentration) to the culture medium. a Time-lapse inverted contrast microscopy images of the siCNS and siILK cells on uncoated dishes taken at a time interval of 15 s showing cells immediately before (− 15 s) and after (90 s, 5 min, and 55 min) adding the serum to the starved cells. b Histograms of the percentage of cells (collapsed vs total cells) that show detachment and retraction of their peripheral plasma membrane before (serum: -) and 20 to 30 min after adding the serum (+). Assays on uncoated dishes were also performed with cells pretreated with 20 μM of the ROCK inhibitor Y-27632. Results are expressed as mean ± SEM. *** p < 0.001 in paired t-test on the average values (siCNS vs siILK; only the statistically significant difference is indicated; n ≥ 3, 363 ± 151 cells counted for every specific condition in each experiment). s: second; min: minute. Scale bar in (a): 20 μm