Human ProS inhibits the capacity of EC to form capillary-like networks in vitro. (A) The in vitro morphogenesis assay. ECs (105 cells/well) were cultured for 24 hours in EBM-2 medium containing 0.5% FCS in 24-well plates coated with Matrigel containing the indicated concentrations of human ProS, endostatin, or albumin. Cells were then fixed and the cell 3-dimensional organization was photographed using a MVX10 microscope. On the pictures, arrows indicate examples of tube formation, and each black scale represents 1 mm length. (B) The quantification of total tube length of capillary-like structures by automatic counting using the AngioQuant Version 1.33 software. Data from 4 independent experiments, each in duplicate, are expressed as percentages of control values form untreated cells ± SD. ***P < .001. *P < .05. ns indicates not significant.
