Hypoxia changes cell spreading and migration.

<p>(A) Spreading of L929 cells in normoxia and hypoxia. L929 cells were incubated under normoxic (20% O₂) or hypoxic conditions (1% O₂), trypsinized and replated for 20 min. Cells were fixed, stained with phalloidin-FITC and divided into three categories (a: round, barely spread; b: in the course of spreading; c: well spread). The percentage of cells in each category was determined. Note that L929 fibroblasts spread faster under hypoxic conditions. (B) Scratch wound healing assays under normoxic and hypoxic conditions. The cell monolayer was scratched with a sterile pipette tip. Images were taken 6, 12, 30 hrs after wounding and the cell-free area was determined. Note that L929 fibroblasts in hypoxia migrate slower into the scratch. (C) Single cell migration of L929 fibroblasts. After 24 hrs of normoxic and hypoxic incubation bright field images of the cells were taken over a period of 360 min. Images were superimposed and the path of the cells was reconstructed by monitoring the cells at each timepoint (going from black to brown). Note that single cell migration is slower under hypoxic conditions. Numbers within the bars indicate the number of cells analysed. * <i>p</i><0.05, ** <i>p</i><0.01, *** <i>p</i><0.001. Bars represent mean values±SEM.