FIG. 4.

(A–F) Micrographs from time-lapse photography (every 15 min for 1.5 h) showing behavior of labeled WJ-MSC over HUVEC monolayers. Cell 1 can be seen displaying blebbing behavior (A, B) followed by rounding (after 30 min; C), and flattening (D–F). Cell 2 can be seen blebbing (A, B), crawling (C), rounding (D), and flattening (E, F). (G–L) Micrographs from a second time-lapse movie (every 15 min for 1.5 h). Cell 3 can be seen demonstrating pseudopodia and crawling movement over HUVEC monolayer (G–I), rounding (J, K) before becoming spindle shaped (L). From (A–C) micrographs were focused on WJ-MSC, whereas micrographs from (D–L) were focused on HUVEC. WJ-MSC have not crossed the HUVEC monolayer in these micrographs of early events. Secreted PKH26-labeled exosome (yellow arrow) can be seen in (J), (K), and (L). Bar=6 μm. Color images available online at www.liebertpub.com/scd