Increases in the number of colonies of LECs by COMP-Ang-1. (A-B) Lower magnification photographs of ALY7-stained LEC colonies are shown. The number of colonies in cultures supplemented with COMP-Ang-1 (B) increased compared to controls (A). (C) Higher magnification photographs of ALY7-stained LEC colonies. Bar indicates 200 μm. (D) Quantitative analysis of ALY7-stained LEC colony formation. Columns represent the relative number of packed round colonies, which is expressed as a percentage against untreated cultures. LEC colonies in culture with COMP-Ang-1 were significantly increased in number compared to those cultured without COMP-Ang-1. The addition of soluble Tie2-Fc reduced the Ang-1-induced increase in the number of colonies to the basal value, whereas the inhibitory effect of VEGFR-3-Fc protein on the Ang-1-induced increase in the number of colonies was partial. The graphs represent the mean ± SEM (n = 6).