Development and characterization of accurate angiogenesis models, in vitro, is paramount to further advancing our understanding of angiogenesis regulation. In Single-Cell Receptor Quantification of an In Vitro Coculture Angiogenesis Model Reveals VEGFR, NRP1, Tie2, and PDGFR Regulation and Endothelial Heterogeneity, published in the Special Issue Systems Biomedicine of Processes, Drs Chen and Imoukhuede quantify six angiogenic receptors in co-cultures containing human umbilical vein endothelial cells and human dermal fibroblasts. Key findings include,
Within 24 h coculturing, we observed ~2700 VEGFR1 per cell on HDFs, which do not natively express VEGFR when cultured alone. In line with the proangiogenic role of VEGFR2, we observed 20–140% increase in plasma membrane VEGFR2 concentrations (4000–8100 receptors per cell) on cocultured HUVECs as tubules develop when compared to monocultures. We observed a ~50% increase in Tie2 concentration on HUVECs during late-stage tube formation, which aligns with the theory that Ang–Tie2 signaling mediates quiescence of blood vessels. We showed steady increase of PDGFRs on HDFs; in particular, PDGFRβs were found on HUVECs during the first 6 h of coculturing (1900–2900 PDGFRβs per cell). These quantitative findings showcased for the first time how EC-stromal contact affects plasma membrane receptor concentrations when compared to EC monocultures.