IL-9 induces angiogenesis in mice and tube formation in HDMEC.

<p>(<b>A</b>) Representative photomicrographs of VEGF and CD31 staining of paraffin-embedded sections of skin from WT or K5.hTGF-β1 transgenic mice injected intradermally for 4 days with 500 ng of IL-9 or vehicle (PBS) (Scale bar 200 µm). (<b>B,C</b>) Semi-quantitative scoring of VEGF and CD31 positivity (n = 4 mice per group). (<b>D</b>) <i>In vitro</i> angiogenesis assay (tube formation) was performed with human dermal micro vascular endothelial cells (HDMEC) in the presence or absence of IL-9 (scale bars 100 µm). (<b>E</b>) Bifurcations were counted as a measure of blood vessel formation. Data are from one of two independent experiments (n = 5 random fields in each sample). Error bars represent SEM. *, p)0.05; ***, p)0.001. (unpaired t-test). Similar results were obtained in three independent experiments.