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Neuropilin-1 functions as a VEGFR2 co-receptor to guide developmental angiogenesis independent of ligand binding.

Gelfand MV, Hagan N, Tata A, Oh WJ, Lacoste B, Kang KT, Kopycinska J, Bischoff J, Wang JH, Gu C - Elife (2014)

Bottom Line: In this study, we generated a mouse line harboring a point mutation in the endogenous Nrp1 locus that selectively abolishes VEGF-NRP1 binding (Nrp1(VEGF-)).Moreover, we found that Nrp1-deficient vessels have reduced VEGFR2 surface expression in vivo demonstrating that NRP1 regulates its co-receptor, VEGFR2.Given the resources invested in NRP1-targeted anti-angiogenesis therapies, our results will be integral for developing strategies to re-build vasculature in disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology, Harvard Medical School, Boston, United States.

ABSTRACT
During development, tissue repair, and tumor growth, most blood vessel networks are generated through angiogenesis. Vascular endothelial growth factor (VEGF) is a key regulator of this process and currently both VEGF and its receptors, VEGFR1, VEGFR2, and Neuropilin1 (NRP1), are targeted in therapeutic strategies for vascular disease and cancer. NRP1 is essential for vascular morphogenesis, but how NRP1 functions to guide vascular development has not been completely elucidated. In this study, we generated a mouse line harboring a point mutation in the endogenous Nrp1 locus that selectively abolishes VEGF-NRP1 binding (Nrp1(VEGF-)). Nrp1(VEGF-) mutants survive to adulthood with normal vasculature revealing that NRP1 functions independent of VEGF-NRP1 binding during developmental angiogenesis. Moreover, we found that Nrp1-deficient vessels have reduced VEGFR2 surface expression in vivo demonstrating that NRP1 regulates its co-receptor, VEGFR2. Given the resources invested in NRP1-targeted anti-angiogenesis therapies, our results will be integral for developing strategies to re-build vasculature in disease.

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The Nrp1VEGF− mutants have delayed blood flow recovery following femoral artery ligation.(A) Laser doppler imaging demonstrates severe hindlimb ischemia directly after femoral artery ligation in both control and Nrp1VEGF− animals (arrows). Five days after surgery, blood flow recovery in the injured hindlimb was significantly greater in control vs Nrp1VEGF− animals (arrowheads). (B) Quantification of blood flow recovery following femoral artery ligation, n = 7.DOI:http://dx.doi.org/10.7554/eLife.03720.016
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fig6s1: The Nrp1VEGF− mutants have delayed blood flow recovery following femoral artery ligation.(A) Laser doppler imaging demonstrates severe hindlimb ischemia directly after femoral artery ligation in both control and Nrp1VEGF− animals (arrows). Five days after surgery, blood flow recovery in the injured hindlimb was significantly greater in control vs Nrp1VEGF− animals (arrowheads). (B) Quantification of blood flow recovery following femoral artery ligation, n = 7.DOI:http://dx.doi.org/10.7554/eLife.03720.016

Mentions: In addition, Nrp1VEGF− animals were also assessed for injury-induced arteriogenesis following femoral artery ligation. In this assay, the femoral artery was surgically severed in both Nrp1VEGF− and control mice, and blood flow recovery was monitored via deep penetrating laser Doppler imaging. Femoral artery ligation produced a comparable level of hindlimb ischemia in the Nrp1VEGF− mutants and controls (Figure 6—figure supplement 1). However, the Nrp1VEGF− mutants exhibited a significant delay in hindlimb re-perfusion. Building upon these results, future work will utilize the Nrp1VEGF− knock-in line to determine if VEGF-NRP1 signaling functions in pathological or physiological angiogenesis in the adult.


Neuropilin-1 functions as a VEGFR2 co-receptor to guide developmental angiogenesis independent of ligand binding.

Gelfand MV, Hagan N, Tata A, Oh WJ, Lacoste B, Kang KT, Kopycinska J, Bischoff J, Wang JH, Gu C - Elife (2014)

The Nrp1VEGF− mutants have delayed blood flow recovery following femoral artery ligation.(A) Laser doppler imaging demonstrates severe hindlimb ischemia directly after femoral artery ligation in both control and Nrp1VEGF− animals (arrows). Five days after surgery, blood flow recovery in the injured hindlimb was significantly greater in control vs Nrp1VEGF− animals (arrowheads). (B) Quantification of blood flow recovery following femoral artery ligation, n = 7.DOI:http://dx.doi.org/10.7554/eLife.03720.016
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4197402&req=5

fig6s1: The Nrp1VEGF− mutants have delayed blood flow recovery following femoral artery ligation.(A) Laser doppler imaging demonstrates severe hindlimb ischemia directly after femoral artery ligation in both control and Nrp1VEGF− animals (arrows). Five days after surgery, blood flow recovery in the injured hindlimb was significantly greater in control vs Nrp1VEGF− animals (arrowheads). (B) Quantification of blood flow recovery following femoral artery ligation, n = 7.DOI:http://dx.doi.org/10.7554/eLife.03720.016
Mentions: In addition, Nrp1VEGF− animals were also assessed for injury-induced arteriogenesis following femoral artery ligation. In this assay, the femoral artery was surgically severed in both Nrp1VEGF− and control mice, and blood flow recovery was monitored via deep penetrating laser Doppler imaging. Femoral artery ligation produced a comparable level of hindlimb ischemia in the Nrp1VEGF− mutants and controls (Figure 6—figure supplement 1). However, the Nrp1VEGF− mutants exhibited a significant delay in hindlimb re-perfusion. Building upon these results, future work will utilize the Nrp1VEGF− knock-in line to determine if VEGF-NRP1 signaling functions in pathological or physiological angiogenesis in the adult.

Bottom Line: In this study, we generated a mouse line harboring a point mutation in the endogenous Nrp1 locus that selectively abolishes VEGF-NRP1 binding (Nrp1(VEGF-)).Moreover, we found that Nrp1-deficient vessels have reduced VEGFR2 surface expression in vivo demonstrating that NRP1 regulates its co-receptor, VEGFR2.Given the resources invested in NRP1-targeted anti-angiogenesis therapies, our results will be integral for developing strategies to re-build vasculature in disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology, Harvard Medical School, Boston, United States.

ABSTRACT
During development, tissue repair, and tumor growth, most blood vessel networks are generated through angiogenesis. Vascular endothelial growth factor (VEGF) is a key regulator of this process and currently both VEGF and its receptors, VEGFR1, VEGFR2, and Neuropilin1 (NRP1), are targeted in therapeutic strategies for vascular disease and cancer. NRP1 is essential for vascular morphogenesis, but how NRP1 functions to guide vascular development has not been completely elucidated. In this study, we generated a mouse line harboring a point mutation in the endogenous Nrp1 locus that selectively abolishes VEGF-NRP1 binding (Nrp1(VEGF-)). Nrp1(VEGF-) mutants survive to adulthood with normal vasculature revealing that NRP1 functions independent of VEGF-NRP1 binding during developmental angiogenesis. Moreover, we found that Nrp1-deficient vessels have reduced VEGFR2 surface expression in vivo demonstrating that NRP1 regulates its co-receptor, VEGFR2. Given the resources invested in NRP1-targeted anti-angiogenesis therapies, our results will be integral for developing strategies to re-build vasculature in disease.

Show MeSH
Related in: MedlinePlus