Fig. 1
A fast transient endocytic response to decrease in membrane tension. a Cartoon showing membrane remodeling responses after mechanical strain. Cells after the stretch and relax protocol form invaginations termed ‘reservoirs’6. These reservoirs are resorbed in a few minutes by an active process and requires ATP. b The illustration shows the longitudinal section of a vacuum-based equi-bi-axial stretching device. Cells plated on a PDMS sheet are stretched by the application of controlled vacuum below the circular PDMS sheet, which stretches it in a calibrated manner. Releasing the vacuum relaxes the strain on PDMS thus relaxing the cell. Cells plated on PDMS can be imaged in an upright or inverted microscope as required. c Fluid uptake (90 s) in CHO cells at steady state (steady state), immediately on relaxing the stretch (stretch–relax), or after a waiting time of 90 s on relaxing the stretch (stretch–relax–wait) (n = control (316), stretch–relax (257), stretch–relax–wait (277)). d Fluid uptake in CHO cells for 3 min in adhered cells (Spread), during de-adhering (Deadh), or immediately after cells are detached and in suspension (Suspension). Images and box plot show the extent of fluid-phase uptake under the indicated conditions (n = spread (196), deadh (241), suspension (274)). Box plot shows median, 25th and 75th percentile, and whiskers show the standard deviation. Individual data points are overlaid on box plot where each data point is the mean intensity per cell. The ‘n’ indicates total number of cells in each condition pooled from two different experiments with duplicates per experiment; *p < 0.001, ns not significant by Mann–Whitney U test. Scale bar, 10 µm
