Figure 1.

Loss of Cx37 reduces angiogenesis in subcutaneous matrigel plugs. (A,B) Representative pictures of matrigel plugs without and with VEGF (A) or FGF2 (B), one week after s.c. injection in WT and Cx37−/− mice. In the absence of vascular growth factors, the plugs retained their original whitish color, due to the absence of vascularization. In the presence of the growth factors, the plugs implanted in WT mice acquired a red-brown color, reflecting their neovascularization, as also judged by a sizable hemoglobin content. Both the color change and the hemoglobin content of the plugs were significantly lower in the plugs implanted in Cx37−/− mice. Data are means + SEM. n = 13 WT and 9 Cx37−/− mice. ** p < 0.01, *** p < 0.001 versus WT mice (Student’s t-test). (C) Matrigel plugs containing VEGF were supplemented with either the ^37,43Gap27 peptide or its scrambled version, before implantation in WT mice. The peptide targeting Cx37 markedly reduced the color change and the hemoglobin content of the plugs, which retained the whitish appearance of the controls devoid of VEGF, and which was similar to that observed in Cx37−/− mice. In contrast, plugs loaded with VEGF and the scrambled peptide became red-stained and featured a large increase in hemoglobin content, as observed in WT mice. Data are mean + SEM. n = 5–6 mice per group. * p < 0.05 versus scramble (one-way ANOVA followed by Tukey’s post-test).