Extended Data Fig. 2: Cells dynamically align in the tension direction via an active actin-dependent process.
From: Interplay of actin nematodynamics and anisotropic tension controls endothelial mechanics
A Endothelium stained for phalloidin (i) and VE-cadherin (ii) at t = 24 h under 650 Pa, with the orientation of the actin stress fibers and junctions color coded. Nuclei are overlaid in white (ii). B Evolution of the probability distribution of the nuclei orientation (i) and the associated nematic order parameter Qn (ii) at 0 (yellow, n=8), 7 (orange, n=9), 24 (red, n=5) and 56 (purple, n=2) hours. The sign of Qn denotes the direction of the orientation and the absolute value its strength. Biii Qn as a function of the cell elongation order parameter Q, showing a linear empirical correlation, color coded for time (0h yellow, 7h orange, 24h red and 56h purple, same data as in Fig. 2div, Extended Data Fig. 2Bii). C Mean nucleus aspect ratio as a function of time. D Cytochalasin-treated monolayer stained for nuclei, VE-cadherin and phalloidin after 7h of pressure showing round cells, the presence of cell-cell junctions and the absence of actin fibers. Scale bar 50 μm. E Evolution of the probability distribution of the nuclei orientation before the pressure increase (ΔP ≃ 150Pa, yellow, n=8), and after 7h of high pressure for the control (ΔP≈650Pa, orange, n=7) and cytochalasin-treated (green, n=3) monolayers.
