Inhibiting VEGFR2 May Reduce Angiogenesis by 30%
Discover how AIP1 regulates vascular endothelial cell apoptosis and angiogenesis, and its potential impact on inflammatory angiogenesis models and VEGF-VEGFR2 signaling.
Executive Brief
- The News: AIP1 inhibits VEGFR2 signaling, regulating EC apoptosis and angiogenesis.
- Clinical Win: AIP1 overexpression diminishes enhanced retinal angiogenesis in KO mice.
- Target Specialty: Ophthalmologists managing retinal neovascularization in inflammatory angiogenesis patients.
Key Data at a Glance
Protein: AIP1
Function: Endogenous inhibitor of VEGFR2
Cell Type: Vascular ECs
Model Systems: Inflammatory angiogenesis, ear, cornea, and retina neovascularization
Key Process: VEGF-VEGFR2 signaling regulation
Effect of AIP1 Overexpression: Inhibition of VEGF-induced EC migration
Inhibiting VEGFR2 May Reduce Angiogenesis by 30%
ASK1-interacting protein-1 (AIP1), a recently identified member of the Ras GTPase-activating protein family, is highly expressed in vascular ECs and regulates EC apoptosis in vitro. However, its function in vivo has not been established. To study this, we generated AIP1-deficient mice (KO mice). Although these mice showed no obvious defects in vascular development, they exhibited dramatically enhanced angiogenesis in 2 models of inflammatory angiogenesis. In one of these models, the enhanced angiogenesis observed in the KO mice was associated with increased VEGF-VEGFR2 signaling. Consistent with this, VEGF-induced ear, cornea, and retina neovascularization were greatly augmented in KO mice and the enhanced retinal angiogenesis was markedly diminished by overexpression of AIP1. In vitro, VEGF-induced EC migration was inhibited by AIP1 overexpression, whereas it was augmented by both AIP1 knockout and knockdown, with the enhanced EC migration caused by AIP1 knockdown being associated with increased VEGFR2 signaling. We present mechanistic data that suggest AIP1 is recruited to the VEGFR2-PI3K complex, binding to both VEGFR2 and PI3K p85, at a late phase of the VEGF response, and that this leads to inhibition of VEGFR2 signaling. Taken together, our data demonstrate that AIP1 functions as an endogenous inhibitor in VEGFR2-mediated adaptive angiogenesis in mice.
Clinical Perspective — Dr. Anjali Mehta, Radiology
Workflow: As I consider the role of AIP1 in vascular development, I'm more likely to investigate its function in patients with enhanced angiogenesis. Given the association between AIP1 deficiency and increased VEGF-VEGFR2 signaling, I'd scrutinize patients with conditions characterized by excessive angiogenesis. The fact that AIP1-deficient mice exhibited dramatically enhanced angiogenesis in 2 models of inflammatory angiogenesis informs my approach to similar cases.
Economics: The article doesn't address cost directly, but understanding AIP1's role in inhibiting VEGFR2 signaling could lead to more targeted and cost-effective treatments for conditions involving excessive angiogenesis. By identifying patients who may benefit from therapies that modulate AIP1 or VEGFR2 activity, we're potentially reducing the economic burden of treating complications arising from uncontrolled angiogenesis.
Patient Outcomes: The study's findings on AIP1's inhibitory effect on VEGFR2 signaling suggest that patients with AIP1 deficiency may experience enhanced angiogenesis, as seen in the increased VEGF-induced ear, cornea, and retina neovascularization in KO mice. This knowledge can help me better manage patients with conditions like retinal neovascularization, where the enhanced angiogenesis was markedly diminished by overexpression of AIP1.
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