[PDF][PDF] G13 controls angiogenesis through regulation of VEGFR-2 expression

KK Sivaraj, M Takefuji, I Schmidt, RH Adams… - Developmental cell, 2013 - cell.com
KK Sivaraj, M Takefuji, I Schmidt, RH Adams, S Offermanns, N Wettschureck
Developmental cell, 2013cell.com
At sites of angiogenesis, the expression of the key angiogenesis regulator vascular
endothelial growth factor (VEGF) and its main receptor, VEGF receptor 2 (VEGFR-2), are
strongly upregulated. Whereas the processes controlling VEGF expression are well
described, the mechanisms underlying VEGFR-2 upregulation have remained unclear. We
found that endothelial VEGFR-2 expression is strongly reduced in the absence of the G
protein G 13, resulting in an impaired responsiveness to VEGF-A, a phenotype that can be …
Summary
At sites of angiogenesis, the expression of the key angiogenesis regulator vascular endothelial growth factor (VEGF) and its main receptor, VEGF receptor 2 (VEGFR-2), are strongly upregulated. Whereas the processes controlling VEGF expression are well described, the mechanisms underlying VEGFR-2 upregulation have remained unclear. We found that endothelial VEGFR-2 expression is strongly reduced in the absence of the G protein G13, resulting in an impaired responsiveness to VEGF-A, a phenotype that can be rescued by normalization of VEGFR-2 levels. G13-mediated VEGFR-2 expression involved activation of the small GTPase RhoA and transcription factor NF-κB, the latter acting via a specific binding site at position −84 of the VEGFR-2 promoter. Mice with endothelial cell-specific loss of G13 showed reduced VEGFR-2 expression at sites of angiogenesis and attenuated VEGF effects, resulting in impaired retinal angiogenesis and tumor vascularization. Taken together, we identified G-protein-mediated signaling via G13 as a critical regulator of VEGFR-2 expression during angiogenesis.
cell.com