Fig. 5
Apical surface effective viscosity is elevated in ZO-1/ZO-2 dKD polarized epithelium and additional actomyosin perturbations significantly modify its behavior. a ZO-1/ZO-2 dKD in MDCK II Tet-off cells significantly increases the epithelial effective viscosity. Number of measurements pooled for 2–3 independent experiments for each condition, n = 28, 25, 26, and 23 for control, ZO-1/ZO-2 dKD, ZO1R(U), and ZO1R(I), respectively. b Epithelial effective viscosity of MDCK II control untreated polarized monolayers, and treated either with 100 µM blebbistatin, 30 µM Y-27632, 2 µM ML-7, or 30 µM Y-27632 + 2 µM ML-7. c Epithelial effective viscosity of MDCK II ZO-1/ZO-2 dKD untreated polarized monolayers, or treated either with 100 µM blebbistatin, 30 µM Y-27632, 2 µM ML-7, or 30 µM Y-27632 + 2 µM ML-7. Inhibition of myosin II ATPase activity, ROCK signaling, and MLCK activity significantly reduces the epithelial effective viscosity. Combine inhibition of ROCK signaling and MLCK activity further reduces the epithelial viscosity. Confluent monolayers of MDCK II controls and ZO-1/ZO-2 dKD cells were treated with the pharmacological drugs for 15 to 20 h. Number of measurements pooled for 2–3 independent experiments for each condition, n = 28, 27, 24, 30, and 29 for control, 100 µM blebbistatin, 30 µM Y-27632, 2 µM ML-7, and 30 µM Y-27632 + 2 µM ML-7, respectively, and n = 25, 15, 20, 28, and 28 for ZO-1/ZO-2 dKD, 100 µM blebbistatin, 30 µM Y-27632, 2 µM ML-7, and 30 µM Y-27632 + 2 µM ML-7, respectively. All data are represented as mean ± s.d.; * indicates significant difference in comparison with control P < 0.05 (unpaired two-tailed Student’s t-test with Welch’s correction)
