Figure 4

Proliferation of exogenous cell types treated with embryoid body conditioned medium. (A) Conditioned medium at day 6 (CM 6) and at day 12 (CM 12) increased fibroblast proliferation compared with unconditioned medium (uCM). CM at day 9 (CM 9) elicited less mitogenic response compared with CM 6 and CM 12. (B) Early time points of embryoid body (EB)-CM did not significantly induce endothelial cell proliferation compared with uCM, whereas CM 12 exhibited significantly greater proliferative response than all other EB-CMs and uCM. Results indicate the mean ± standard error (n = 6). Top row: phase images, scale bar = 50 μm. Bottom row: fluorescent images, blue = Hoechst stain, green = 5-bromo-2′-deoxyuridine (BrdU)-positive cells, scale bar = 50 μm. Dashed line, % BrdU-positive cells stimulated by the respective cell type’s growth media. Analysis of variance: *P < 0.05 compared with uCM; #P < 0.05 compared with growth media; †P < 0.05 compared with CM 6 and CM 12; ‡P < 0.05 compared with CM 6 and CM 9. HUVEC, human umbilical vein endothelial cell.