CCN2 potentiates PDGF-B signaling.

<p>(A) rCCN2 induces PDGF-B expression in HUVEC cells. Right panel, representative Western blot. Left panel, Quantification of relative expression levels of PDGF-B in cells treated with or without rCCN2 from three separate experiments. *, p<0.02. (B) Adenovirally expressed CCN2 induces PDGF-B expression in HUVECs compared to transfection with an empty adenoviral control. The extent of PDGF-B induction correlated with levels of CCN2 expression. As reported previously, a higher molecular weight isoform of CCN2, presumably a result of post-translational modification <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030562#pone.0030562-Brigstock1" target="_blank">[1]</a>, is detected 4 and 8 hours post-infection. Relative level of PDGF-B expression was assessed using ImageJ software. The experiment was repeated three times, with similar results each time. The induction of PDGF-B in the presence of CCN2 was statistically significant for each time point; p<0.05. A representative Western blot is shown. (C) Effects of rPDGF-B, and/or pcDNA3-CCN2-HA expression on activation of PDGF pathways in MOVAS cells. PDGF-B stimulated activation of Stat3, ERK, and Akt, whereas CCN2-HA on its own had no effect. However, combined treatment with PDGF-B and CCN2-HA led to prolonged Akt activation (arrows). Relative levels of pAKT expression were assessed using ImageJ software. All experiments were performed in triplicate and repeated three times, with similar results each time. The increase in pAKT levels in the presence of CCN2 was statistically significant at each time point; p<0.05. A representative Western blot is shown.