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Endothelial Snail Regulates Capillary Branching Morphogenesis via Vascular Endothelial Growth Factor Receptor 3 Expression.

Park JA, Kim DY, Kim YM, Lee IK, Kwon YG - PLoS Genet. (2015)

Bottom Line: Results from in vitro functional studies demonstrate that Snail expression colocalized with VEGFR3 and upregulated VEGFR3 mRNA by directly binding to the VEGFR3 promoter via cooperating with early growth response protein-1.Snail knockdown in postnatal mice attenuated the formation of the deep capillary plexus, not only by impairing vertical sprouting vessels but also by downregulating VEGFR3 expression.Collectively, these data suggest that the Snail-VEGFR3 axis controls capillary extension, especially in vessels expressing VEGFR2 at low levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea.

ABSTRACT
Vascular branching morphogenesis is activated and maintained by several signaling pathways. Among them, vascular endothelial growth factor receptor 2 (VEGFR2) signaling is largely presented in arteries, and VEGFR3 signaling is in veins and capillaries. Recent reports have documented that Snail, a well-known epithelial-to-mesenchymal transition protein, is expressed in endothelial cells, where it regulates sprouting angiogenesis and embryonic vascular development. Here, we identified Snail as a regulator of VEGFR3 expression during capillary branching morphogenesis. Snail was dramatically upregulated in sprouting vessels in the developing retinal vasculature, including the leading-edged vessels and vertical sprouting vessels for capillary extension toward the deep retina. Results from in vitro functional studies demonstrate that Snail expression colocalized with VEGFR3 and upregulated VEGFR3 mRNA by directly binding to the VEGFR3 promoter via cooperating with early growth response protein-1. Snail knockdown in postnatal mice attenuated the formation of the deep capillary plexus, not only by impairing vertical sprouting vessels but also by downregulating VEGFR3 expression. Collectively, these data suggest that the Snail-VEGFR3 axis controls capillary extension, especially in vessels expressing VEGFR2 at low levels.

No MeSH data available.


Related in: MedlinePlus

Vertically sprouting vessels have strong VEGFR3, but weak VEGFR2, expression in the developing retinal vasculature.(A) Cross-sectional confocal images showing the differential expression pattern of VEGFR2 and VEGFR3 in P11 mice. The immunoreactivity of VEGFR3 was strongly detected in the vertical vessels (IPL and INL; triangles) and deep plexus (OPL, triangles). In contrast, strong immunoreactivity of VEGFR2 was detected in the superficial plexus (GCL, arrows) and neurons (arrow heads). Nuclei were DAPI positive (blue). ONL, outer nuclear layer. Bar, 100 μm. (B and C) Confocal images of VEGFR3 staining in the superficial plexus at P8. Eyeballs from P8 mice were applied to whole flat-mount staining of iB4 and VEGFR3. The region in the box (B) is magnified in C (upper). The region of the vertical vessel was taken below the superficial plexus. (C, lower) The immunoreactivity of VEGFR3 was detected in sprouting vessels from the vein (arrows). Broken lines correspond to the position of vein that appeared in the superficial plexus. A, artery; V, vein. Nuclei were DAPI positive (blue). Bar, 100 μm.
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pgen.1005324.g005: Vertically sprouting vessels have strong VEGFR3, but weak VEGFR2, expression in the developing retinal vasculature.(A) Cross-sectional confocal images showing the differential expression pattern of VEGFR2 and VEGFR3 in P11 mice. The immunoreactivity of VEGFR3 was strongly detected in the vertical vessels (IPL and INL; triangles) and deep plexus (OPL, triangles). In contrast, strong immunoreactivity of VEGFR2 was detected in the superficial plexus (GCL, arrows) and neurons (arrow heads). Nuclei were DAPI positive (blue). ONL, outer nuclear layer. Bar, 100 μm. (B and C) Confocal images of VEGFR3 staining in the superficial plexus at P8. Eyeballs from P8 mice were applied to whole flat-mount staining of iB4 and VEGFR3. The region in the box (B) is magnified in C (upper). The region of the vertical vessel was taken below the superficial plexus. (C, lower) The immunoreactivity of VEGFR3 was detected in sprouting vessels from the vein (arrows). Broken lines correspond to the position of vein that appeared in the superficial plexus. A, artery; V, vein. Nuclei were DAPI positive (blue). Bar, 100 μm.

Mentions: At P11, the superficial plexus had been fully formed, and it vertically extended toward the deep retina. We determined that the immunoreactivity of VEGFR2 was strong in the GCL of retinas (Fig 5A, upper panel, arrows). In contrast, the immunoreactivity of VEGFR3 was weak in the same area (Fig 5A, middle, arrows). Interestingly, VEGFR3 was strongly detected in vertically invading capillaries toward the deep retina (Fig 5A, middle panel, triangles). Serial z-axis analysis showed that VEGFR3 was highly expressed in deep capillary vessels and migrating and sprouting ECs (S6 Fig). VEGFR2 was barely detected in the vertical vessels, but it appeared to be expressed in neuronal cells (Fig 5A, upper panel, triangles and arrow heads).


Endothelial Snail Regulates Capillary Branching Morphogenesis via Vascular Endothelial Growth Factor Receptor 3 Expression.

Park JA, Kim DY, Kim YM, Lee IK, Kwon YG - PLoS Genet. (2015)

Vertically sprouting vessels have strong VEGFR3, but weak VEGFR2, expression in the developing retinal vasculature.(A) Cross-sectional confocal images showing the differential expression pattern of VEGFR2 and VEGFR3 in P11 mice. The immunoreactivity of VEGFR3 was strongly detected in the vertical vessels (IPL and INL; triangles) and deep plexus (OPL, triangles). In contrast, strong immunoreactivity of VEGFR2 was detected in the superficial plexus (GCL, arrows) and neurons (arrow heads). Nuclei were DAPI positive (blue). ONL, outer nuclear layer. Bar, 100 μm. (B and C) Confocal images of VEGFR3 staining in the superficial plexus at P8. Eyeballs from P8 mice were applied to whole flat-mount staining of iB4 and VEGFR3. The region in the box (B) is magnified in C (upper). The region of the vertical vessel was taken below the superficial plexus. (C, lower) The immunoreactivity of VEGFR3 was detected in sprouting vessels from the vein (arrows). Broken lines correspond to the position of vein that appeared in the superficial plexus. A, artery; V, vein. Nuclei were DAPI positive (blue). Bar, 100 μm.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
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pgen.1005324.g005: Vertically sprouting vessels have strong VEGFR3, but weak VEGFR2, expression in the developing retinal vasculature.(A) Cross-sectional confocal images showing the differential expression pattern of VEGFR2 and VEGFR3 in P11 mice. The immunoreactivity of VEGFR3 was strongly detected in the vertical vessels (IPL and INL; triangles) and deep plexus (OPL, triangles). In contrast, strong immunoreactivity of VEGFR2 was detected in the superficial plexus (GCL, arrows) and neurons (arrow heads). Nuclei were DAPI positive (blue). ONL, outer nuclear layer. Bar, 100 μm. (B and C) Confocal images of VEGFR3 staining in the superficial plexus at P8. Eyeballs from P8 mice were applied to whole flat-mount staining of iB4 and VEGFR3. The region in the box (B) is magnified in C (upper). The region of the vertical vessel was taken below the superficial plexus. (C, lower) The immunoreactivity of VEGFR3 was detected in sprouting vessels from the vein (arrows). Broken lines correspond to the position of vein that appeared in the superficial plexus. A, artery; V, vein. Nuclei were DAPI positive (blue). Bar, 100 μm.
Mentions: At P11, the superficial plexus had been fully formed, and it vertically extended toward the deep retina. We determined that the immunoreactivity of VEGFR2 was strong in the GCL of retinas (Fig 5A, upper panel, arrows). In contrast, the immunoreactivity of VEGFR3 was weak in the same area (Fig 5A, middle, arrows). Interestingly, VEGFR3 was strongly detected in vertically invading capillaries toward the deep retina (Fig 5A, middle panel, triangles). Serial z-axis analysis showed that VEGFR3 was highly expressed in deep capillary vessels and migrating and sprouting ECs (S6 Fig). VEGFR2 was barely detected in the vertical vessels, but it appeared to be expressed in neuronal cells (Fig 5A, upper panel, triangles and arrow heads).

Bottom Line: Results from in vitro functional studies demonstrate that Snail expression colocalized with VEGFR3 and upregulated VEGFR3 mRNA by directly binding to the VEGFR3 promoter via cooperating with early growth response protein-1.Snail knockdown in postnatal mice attenuated the formation of the deep capillary plexus, not only by impairing vertical sprouting vessels but also by downregulating VEGFR3 expression.Collectively, these data suggest that the Snail-VEGFR3 axis controls capillary extension, especially in vessels expressing VEGFR2 at low levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea.

ABSTRACT
Vascular branching morphogenesis is activated and maintained by several signaling pathways. Among them, vascular endothelial growth factor receptor 2 (VEGFR2) signaling is largely presented in arteries, and VEGFR3 signaling is in veins and capillaries. Recent reports have documented that Snail, a well-known epithelial-to-mesenchymal transition protein, is expressed in endothelial cells, where it regulates sprouting angiogenesis and embryonic vascular development. Here, we identified Snail as a regulator of VEGFR3 expression during capillary branching morphogenesis. Snail was dramatically upregulated in sprouting vessels in the developing retinal vasculature, including the leading-edged vessels and vertical sprouting vessels for capillary extension toward the deep retina. Results from in vitro functional studies demonstrate that Snail expression colocalized with VEGFR3 and upregulated VEGFR3 mRNA by directly binding to the VEGFR3 promoter via cooperating with early growth response protein-1. Snail knockdown in postnatal mice attenuated the formation of the deep capillary plexus, not only by impairing vertical sprouting vessels but also by downregulating VEGFR3 expression. Collectively, these data suggest that the Snail-VEGFR3 axis controls capillary extension, especially in vessels expressing VEGFR2 at low levels.

No MeSH data available.


Related in: MedlinePlus