Figure 4

Schematic of the FACS analysis Two color FACS analysis of the levels of: apoptosis, measured by the TUNEL assay (using fluorescein-dUTP) – FL1; α-SMA – FL2, using a Phycoerythrin-conjugated secondary antibody. Quadrants are defined by background fluorescence of fluorescein and phycoerythrin. Lower Left (LL) quadrant – α-SMA-negative, non-differentiated, non-apoptotic ("Naïve") fibroblasts; Upper Left (UL) quadrant – non-apoptotic cells with higher α-SMA content – non-apoptotic myofibroblasts); Upper Right (UR) quadrant – apoptotic myofibroblasts; Lower Right (LR) quadrant – apoptotic fibroblasts who have either lost the myofibroblast phenotype or have not developed it at all. Apoptotic fibroblasts eventually detach from the plate. Question marks point to putative transitions.