FIG. 2.

Coculture of MSCs in contact with ECs inhibits vascular network formation in vitro. (A) ECs cultured in contact with MSCs for 2 days were separated by MACs using negative selection of CD44-positive cells and then seeded into matrigel. (B) After 6 h of culture in matrigel, ECs cultured in contact with MSCs demonstrate a diminished ability to form vascular networks. The ratio of coculture in all of these experiments was 1:5 MSCs:ECs. Cartoon depicts the separation process with MSCs (green) and ECs (red) with subsequent seeding of the ECs into matrigel. (C) Coculture of MSCs and ECs without contact in transwells enhances vascular network formation. ECs cultured with MSCs in transwells (without contact) for 2 days were seeded into matrigel. After 6 h of culture in matrigel, ECs cultured in contact with MSCs demonstrate an enhanced ability to form vascular networks. The ratio of coculture in all of these experiments was 1:5 MSCs:ECs. (D) Quantitation of capillary branch length measured in 10 random-view fields for each condition. Data show ECs cultured with MSCs (ECs+MSCs) form significantly shorter branches (P<0.05+) in matrigel compared to ECs cultured alone, and ECs cultured with MSCs in transwells ECs+MSCs(TW) form longer branches (P<0.05*) compared to ECs alone. (E) Quantitation of capillary network branch points counted in 10 random-view fields for each condition. Data show that ECs cultured with MSCs (ECs+MSCs) form significantly fewer branch points (P<0.05+) in matrigel compared to ECs cultured alone, and ECs with MSCs in transwells ECs+MSCs(TW) demonstrate enhanced branch point formation (P<0.05*) compared to ECs alone. Tube length is designated as relative length in arbitrary units. Color images available online at www.liebertpub.com/scd