Quantification of 3D ECM remodeling

Quantification of ECM remodeling was performed as described previously (Kraning-Rush et al., 2011). Briefly, collagen gels were fixed 24 h after treatment, and single cells were imaged by confocal reflectance microscopy. The collagen intensity was then analyzed with a custom ImageJ macro (available upon request) along the path of a 100 µm line centered on the cell centroid. The resulting line signal was integrated around the entire cell in 2° increments and the edge of the cell was used to define the origin and obtain the collagen intensity profile. The resulting intensity profiles were fitted with an exponential decay model to extract the characteristic compaction length as described previously (Kraning-Rush et al., 2011).