Key Event Title
Key Event Component
Key Event Overview
AOPs Including This Key Event
Level of Biological Organization
How This Key Event Works
(From: Knudsen TB, Kleinstreuer NC. Disruption of embryonic vascular development in predictive toxicology. Birth Defects Res C Embryo Today. 2011 Dec;93(4):312-23. doi: 10.1002/bdrc.20223. Review. PubMed PMID: 22271680.)
"VEGF-A release from hypoxic cells is the most common angiogenic switch, specifying a pioneering sprouting behavior of EC ‘‘tip-cells.’’ Activation of a G-protein signaling cascade (e.g., RhoA, Rac1, Cdc42) in tip-cells triggers filopodial extensions that probe the surrounding environment and direct cell migration along the VEGF-A gradient. The exploratory behavior and minimal proliferation of a pioneering tip-cell is similar to axonal growth cones, sensing and responding to guidance cues in the local microenvironment."
How It Is Measured or Detected
Methods that have been previously reviewed and approved by a recognized authority should be included in the Overview section above. All other methods, including those well established in the published literature, should be described here. Consider the following criteria when describing each method: 1. Is the assay fit for purpose? 2. Is the assay directly or indirectly (i.e. a surrogate) related to a key event relevant to the final adverse effect in question? 3. Is the assay repeatable? 4. Is the assay reproducible?
Evidence Supporting Taxonomic Applicability
Knudsen TB, Kleinstreuer NC. Disruption of embryonic vascular development in predictive toxicology. Birth Defects Res C Embryo Today. 2011 Dec;93(4):312-23. doi: 10.1002/bdrc.20223. Review. PubMed PMID: 22271680.