Figure 1:

A) Endothelial cell Tie2 signaling during quiescence. Tie2 receptors cluster together and engage tetramers of Angpt-1 which results in activation of the receptor in a trans configuration. Furthermore, Tie1 binding further potentiates Tie2 activation. Downstream activation of Tie2 results in increased barrier function. B) Endothelial cell Tie2 signaling during inflammation. Tie2 receptor binds Angpt-2 dimers resulting in dephosphorylation and FOXO1 migration to the nucleus resulting in translation of inflammatory mediations and additional Angpt-2.