Fig. 6.

Overexpression of p38 increases disassembly of VE-cadherin homodimers to form endothelial gaps. A: transfection efficiency of HUVECs with red fluorescent protein (RFP) or MAP kinase kinase (MKK) 6(glu)/RFP was assessed using Western blots probed for either anti-p38 or anti-phospho-p38. Western blots are representative of three separate experiments. B: HUVECs were transfected with constitutively active MKK6(glu) fused with RFP to label transfected cells. Endothelial gap formation was assessed 36–48 h posttransfection. P values are comparing each experimental condition with %gap of HUVECs alone and HUVECs + RFP (*P < 0.05). C: inhibiting p38 phosphorylation prevents the disassembly of VE-cadherin homodimers. HUVECs were treated with SB-220025 for 30 min before they were cocultured with A2058 melanoma cells for 45 min. Values are means ± SD. P values are comparing each experimental condition with %gap of HUVEC + A2058 cells (*P < 0.05).