Fig. 2
From: Dynamic fibroblast contractions attract remote macrophages in fibrillar collagen matrix
Macrophages (Mϕ) are attracted to myofibroblast (MF) on fibrillar collagen extracellular matrix (ECM). a Mϕ were co-cultured with MFs on top of fibrillar collagen ECM with surface marker beads and b recorded for 8 h at one frame per 5 min. Mϕ (green colored) and beads (red colored) were automatically tracked in phase-contrast videos. c Mϕ tracks (blue-attracted Mϕ, purple-responsive Mϕ, red-non-responsive Mϕ) were plotted with respect to the MF position (0,0). d Mϕ track lengths and velocity were compared with displacement of adjacent microbeads in box (25th to 75th percentiles) and whisker (minimum to maximum) plots with center lines showing medians (20 experiments with average 5 image fields, *p ≤ 0.05 and **p ≤ 0.01, Student’s t test). All Mϕ tracks were subsequently corrected for passive bead dragging. e Fluid flow was applied to eliminate possible chemotactic gradients and f Mϕ tracks were analyzed. g Total migration angle (θ) was defined as the angle between the line connecting the starting point of the Mϕ trajectory and the MF centroid and the line connecting the first and last point of the Mϕ trajectory. h Directedness (D) was defined by the quotient of Euclidian distance and track length. Pie charts summarize Mϕ migration behavior in i no flow conditions (145 Mϕ, 20 experiments) and j under flow (87 Mϕ, 12 experiments). k Local migration velocity (traveled distance dn between two image frames) and migration angle θn to the MF position were calculated for every frame pair. l Local velocities and m angle changes of attracted and responsive Mϕ were plotted over distance to the MF (93 Mϕ, 20 experiments). n Mϕ trajectories were analyzed without MFs present (random migration). o Local migration velocities and p angles of Mϕ migration with respect to the image center (origin) (82 Mϕ, 10 experiments). Shown are medians ± value ranges (*p ≤ 0.05 using analysis of variance (ANOVA) followed by post hoc Tukey’s multiple comparison test). Slope changes were considered significant at *p ≤ 0.05, using slope comparison test. q Average local migration velocities were compared between attracted and responsive Mϕ (n = 19), non-responsive Mϕ (n = 18), and Mϕ migrating randomly without MFs (n = 23). Shown are medians ± value ranges (*p ≤ 0.05 using ANOVA followed by post hoc Tukey’s multiple comparison test)
