Figure 6
From: Notch and VEGF pathways play distinct but complementary roles in tumor angiogenesis
Notch blockade disrupts pericyte interaction with endothelial cells. (A) Immunofluorescence for the mature pericyte marker αSMA (red). NGP-N1D pericytes are discontinuous and their morphology is altered (right top, white arrows), compared to controls (left top). NGP-LacZ + BV vasculature had continuous coverage of pericytes. Pericytes of NGP-N1D + BV tumors showed discontinuity and altered morphology (bottom right, arrows). RBCs autofluoresce green. Bar = 50 μm. (B) Quantification of αSMA showed significant increase in NGP-N1D tumors, with a decrease in NGP-LacZ + BV and NGP-N1D + BV. Error bars represent SD. **P < 0.01, ***P < 0.001. (C) Confocal analysis of immunostaining for PECAM-1 (red) and αSMA (green). NGP-LacZ control tumors demonstrated PECAM-1(+) cells surrounded by αSMA(+) pericytes (upper left, arrows), NGP-Notch1 decoy tumors had stretches of PECAM-1(+) cells without surrounding αSMA(+) pericytes (upper right, arrowheads). NGP-LacZ + BV tumors had PECAM-1(+) cells surrounded by thin layers of αSMA(+) pericytes (lower left, arrow), while NGP-N1D + BV tumors had PECAM-1(+) cells not surrounded by αSMA(+) pericytes (lower right, arrowhead). RBCs are pseudocolored grey.