FIGURE 7:
Microvilli are required for shear-induced vacuole formation. (A) Representative scanning electron micrographs of the apical surfaces of cell monolayers cultured overnight, comparing densely plated Caco-2BBE, Caco-2 parental cells, and less densely (but confluently) plated Caco-2BBE cells. Representative DIC images of shear-induced vacuole formation overnight (B, E), comparing (B) Caco-2BBE (control) with Caco-2 parental and (E) dense (control) with less dense (confluent) plating. Vacuoles are marked in red. (C, F) Quantification of vacuole number as a time course of shear stress or static control, comparing conditions outlined in B and E. Statistical analysis was performed by two-way ANOVA. (D, G) Quantification of the number of dextran-positive vacuoles resulting from overnight shear induction or static control, comparing conditions outlined in B and E. Error bars represent SEM from n = 3 independent experiments. Data scales are normalized values derived from mean centering and variance scaling of each set of experiments. **P < 0.01, ***P < 0.001 by t test.