SDF-1 activity on microvascular endothelial cells: consequences on angiogenesis in in vitro and in vivo models

The chemokine stromal cell-derived factor-1 (SDF-1) has been shown to be involved in cell migration. As the receptor CXCR-4 is expressed on endothelial cells and upregulated by angiogenic factors, we were prompted to study the effect of SDF-1 on angiogenesis in endothelial cells from microvasculature. This study demonstrates that SDF-1 induces an angiogenic effect in vitro, primarily in a tridimensional fibrin gel. The increase in capillary tube formation was evident after a 10-day incubation with SDF-1. This was associated with a mild increase in VEGF production by microvascular endothelial cells (ELISA and rt-PCR) and a potent chemotactic effect. SDF-1 also induced an in vivo angiogenic activity as shown in the model of the rabbit corneal pocket. However, the angiogenesis was located in an area rich in inflammatory cells. The results of our study suggest that these data underline the potential role of SDF-1 in angiogenesis as the microvascular endothelial cells were greatly involved in this process.