Figure 4.

Exploring the influence of SCs on the formation of vascular networks with HMEVCs. (A) Illustration of the experiment where HMVECs were seeded in either normal or SC-conditioned medium, onto Matrigel-coated wells at 75 × 10³ cells/cm², and the resulting network was evaluated after 48 h. Illustration made with biorender (https://biorender.com/). (B) Bright-field micrographs taken 48 h after cell seeding showing the differences in tube formation between normal (left) and SC-conditioned medium (right). Purple traces were drawn on top of the tubes for better visualization. The scale bar represents 2 mm. (C) Quantification of vessel length (left), vessel density (middle), and branching density (right) of HMEVC tubes cultured in normal (black bars) or SC-conditioned (gray bars) medium. The bars represent the mean ± SD from two independent experiments and three replicates per condition. The whole well was imaged to determine the measured parameters. Statistics were performed using an unpaired t-test, where **p < 0.01 and *p < 0.05. (D) Micrographs of 10 DIV cultures of HMEVCs in SC-conditioned medium (top) or HMVECs plus SCs in normal medium (bottom) show vessel formation (CD31, red). SC-conditioned medium was not sufficient to promote vessel formation in 3D cultures, and the presence of SCs was required for vessel formation and maintenance. Scale bars represent 500 μm.