Morphological changes of ECs during angiogenesis in vitro.

Native (a, b, c), control (d, e, f) and knockdown cells (g, h, i) of HD1 are presented at day 5 (a, d, g), 25 (b, e, h) and 50 (c, f, i)., followed by native (j, k, l), control (m, n, o) and knockdown cells (p, q, r) of HD2 at day 5 (j, m, p), 25 (k, n, q), and 50 (l, o, r). In the upper left corner of sh and SCR micrographs, GFP control is shown. In all groups, cells were polygonal and elongated shaped at day 5, representing stage 1–2 (a, d, g, j, m, p). At day 25, native and control cells of both batches displayed networking structures of stage 4–5 (b, e, k, n), followed by three-dimensional organisation of stage 6 (c, f, l, o). In contrast, knockdown cells remain in stage 3, showing linear side-by-side arrangements as the furthest stage of differentiation (h, i, q, r). Scale bars = 100 μm.