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Published on: June 30, 2023
Purinergic regulation of vascular endothelial growth factor signaling in angiogenesis
S M Rumjahn1, N Yokdang, K A Baldwin
1Department of Pharmacology, University of Nevada School of Medicine, Reno, NV 89557, USA.
Abstract:
P2Y purine nucleotide receptors (P2YRs) promote endothelial cell tubulogenesis through breast cancer cell-secreted nucleoside diphosphate kinase (NDPK). We tested the hypothesis that activated P2Y(1) receptors transactivate vascular endothelial growth factor receptor (VEGFR-2) in angiogenic signaling. P2Y(1)R stimulation (10 microM 2-methyl-thio-ATP (2MS-ATP)) of angiogenesis is suppressed by the VEGFR-2 tyrosine kinase inhibitor, SU1498 (1 microM). Phosphorylation of VEGFR-2 by 0.0262 or 2.62 nM VEGF was comparable with 0.01 or 10 microM 2MS-ATP stimulation of the P2Y(1)R. 2MS-ATP, and VEGF stimulation increased tyrosine phosphorylation at tyr1175. 2MS-ATP (0.1-10 microM) also stimulated EC tubulogenesis in a dose-dependent manner. The addition of sub-maximal VEGF (70 pM) in the presence of increasing concentrations of 2MS-ATP yielded additive effects at 2MS-ATP concentrations <3 microM, whereas producing saturated and less than additive effects at > or =3 microM. We propose that the VEGF receptor can be activated in the absence of VEGF, and that the P2YR-VEGFR2 interaction and resulting signal transduction is a critical determinant of vascular homoeostasis and tumour-mediated angiogenesis.
Insights
P2Y1 receptors activate vascular endothelial growth factor receptor-2 (VEGFR-2) to promote angiogenesis. This interaction is crucial for blood vessel formation in vascular homeostasis and tumor growth.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- P2Y purine nucleotide receptors (P2YRs) are involved in endothelial cell tubulogenesis.
- Breast cancer cells secrete nucleoside diphosphate kinase (NDPK), influencing angiogenesis.
- The role of P2Y1 receptors in transactivating VEGFR-2 in angiogenic signaling requires further investigation.
Purpose of the Study:
- To test the hypothesis that activated P2Y1 receptors transactivate VEGFR-2 in angiogenic signaling.
- To investigate the interaction between P2Y1R and VEGFR-2 in endothelial cell tubulogenesis.
- To elucidate the signaling pathway involving P2Y1R and VEGFR-2 in angiogenesis.
Main Methods:
- Stimulation of P2Y1R with 2-methyl-thio-ATP (2MS-ATP) and assessment of angiogenesis.
- Inhibition of VEGFR-2 tyrosine kinase activity using SU1498.
- Measurement of VEGFR-2 phosphorylation at tyr1175 following stimulation with 2MS-ATP and VEGF.
- Dose-dependent analysis of 2MS-ATP on endothelial cell (EC) tubulogenesis.
- Assessment of additive and saturated effects of combined 2MS-ATP and VEGF stimulation.
Main Results:
- P2Y1R stimulation of angiogenesis was suppressed by a VEGFR-2 inhibitor.
- VEGF and 2MS-ATP induced comparable phosphorylation of VEGFR-2 at tyr1175.
- 2MS-ATP dose-dependently stimulated EC tubulogenesis.
- Additive effects of 2MS-ATP and sub-maximal VEGF were observed at lower 2MS-ATP concentrations, with saturated and less than additive effects at higher concentrations.
Conclusions:
- VEGF receptor can be activated independently of VEGF.
- The P2Y1R-VEGFR2 interaction is critical for vascular homeostasis.
- This signaling pathway plays a key role in tumor-mediated angiogenesis.
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