Figure 4.

TNF and growth factor secretion by mesenchymal stem cells in normoxic and hypoxic cultures. (A–C): TNFα secretion (A), VEGF secretion (B), and FGF2 secretion (C) in high- and low-density cultures. All data are normalized to cell number. Error bars represent SEM computed on three to five biologic replicates (distinct donors). Significant differences of relevant comparisons are indicated: ∗, ∗∗, ∗∗∗, ∗∗∗∗, p values of <.05, <.01, <.001, and <.0001, respectively. Abbreviations: FGF2, basic fibroblast growth factor; TNFα, tumor necrosis factor α; VEGF, vascular endothelial growth factor.