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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

Proposed model of capillary branching morphogenesis in postnatal mice.(A) Outline of Snail stabilization by ECM-mediated signaling. Snail is rapidly degraded by the GSK3β-dependent proteosomal system. On exposure of ECs to ECM, they activate Akt, which can suppress GSK3β-dependent system by phosphorylating GSK3β (pGSK3β). This process stabilizes Snail by releasing it from GSK3β system. Thereby, the formation of Snail-Egr-1 complex promotes VEGFR3 expression by binding to the VEGFR3 promoter region to facilitate EC morphogenesis, such as EC sprouting, extension, and branching. pSnail, phosphorylated Snail by GSK3β; pAkt, Akt phosphorylation; E, Egr-1; EC, endothelial cell. (B) Capillary branching morphogenesis is controlled by Snail. In P7–P8 mice, venous ECs in the superficial plexus start to extend capillary branching toward the deep retina in response to tissue needs. The sprouting ECs at the border between the GCL and IPL are exposed to ECM, which subsequently contributes to Snail induction and stabilization, followed by enhanced VEGFR3 expression. Snail/VEGFR3-expressing ECs vertically migrate toward deep retina. At P9–P11 mice, vertically migrating ECs reach in the boundary of INL and turn sideways to form the deep capillary plexus in the OPL region. Snail knockdown attenuates the initiation of EC sprouting, which subsequently impairs the formation of the deep capillary plexus.
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pgen.1005324.g008: Proposed model of capillary branching morphogenesis in postnatal mice.(A) Outline of Snail stabilization by ECM-mediated signaling. Snail is rapidly degraded by the GSK3β-dependent proteosomal system. On exposure of ECs to ECM, they activate Akt, which can suppress GSK3β-dependent system by phosphorylating GSK3β (pGSK3β). This process stabilizes Snail by releasing it from GSK3β system. Thereby, the formation of Snail-Egr-1 complex promotes VEGFR3 expression by binding to the VEGFR3 promoter region to facilitate EC morphogenesis, such as EC sprouting, extension, and branching. pSnail, phosphorylated Snail by GSK3β; pAkt, Akt phosphorylation; E, Egr-1; EC, endothelial cell. (B) Capillary branching morphogenesis is controlled by Snail. In P7–P8 mice, venous ECs in the superficial plexus start to extend capillary branching toward the deep retina in response to tissue needs. The sprouting ECs at the border between the GCL and IPL are exposed to ECM, which subsequently contributes to Snail induction and stabilization, followed by enhanced VEGFR3 expression. Snail/VEGFR3-expressing ECs vertically migrate toward deep retina. At P9–P11 mice, vertically migrating ECs reach in the boundary of INL and turn sideways to form the deep capillary plexus in the OPL region. Snail knockdown attenuates the initiation of EC sprouting, which subsequently impairs the formation of the deep capillary plexus.

Mentions: Findings from this study show that (a) Snail was induced in angiogenically activated ECs in the postnatal retinal vasculature via ECM signaling; (b) the Snail-Egr-1 complex upregulated VEGFR3 mRNA; and (c) Snail knockdown attenuated the formation of the deep vascular plexus by impairing vertical sprouting and affecting VEGFR3 expression. Collectively, the data demonstrate that a Snail-VEGFR3 axis contributed to the extension of capillary vessels and venous vessels (Fig 8).


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)

Proposed model of capillary branching morphogenesis in postnatal mice.(A) Outline of Snail stabilization by ECM-mediated signaling. Snail is rapidly degraded by the GSK3β-dependent proteosomal system. On exposure of ECs to ECM, they activate Akt, which can suppress GSK3β-dependent system by phosphorylating GSK3β (pGSK3β). This process stabilizes Snail by releasing it from GSK3β system. Thereby, the formation of Snail-Egr-1 complex promotes VEGFR3 expression by binding to the VEGFR3 promoter region to facilitate EC morphogenesis, such as EC sprouting, extension, and branching. pSnail, phosphorylated Snail by GSK3β; pAkt, Akt phosphorylation; E, Egr-1; EC, endothelial cell. (B) Capillary branching morphogenesis is controlled by Snail. In P7–P8 mice, venous ECs in the superficial plexus start to extend capillary branching toward the deep retina in response to tissue needs. The sprouting ECs at the border between the GCL and IPL are exposed to ECM, which subsequently contributes to Snail induction and stabilization, followed by enhanced VEGFR3 expression. Snail/VEGFR3-expressing ECs vertically migrate toward deep retina. At P9–P11 mice, vertically migrating ECs reach in the boundary of INL and turn sideways to form the deep capillary plexus in the OPL region. Snail knockdown attenuates the initiation of EC sprouting, which subsequently impairs the formation of the deep capillary plexus.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493050&req=5

pgen.1005324.g008: Proposed model of capillary branching morphogenesis in postnatal mice.(A) Outline of Snail stabilization by ECM-mediated signaling. Snail is rapidly degraded by the GSK3β-dependent proteosomal system. On exposure of ECs to ECM, they activate Akt, which can suppress GSK3β-dependent system by phosphorylating GSK3β (pGSK3β). This process stabilizes Snail by releasing it from GSK3β system. Thereby, the formation of Snail-Egr-1 complex promotes VEGFR3 expression by binding to the VEGFR3 promoter region to facilitate EC morphogenesis, such as EC sprouting, extension, and branching. pSnail, phosphorylated Snail by GSK3β; pAkt, Akt phosphorylation; E, Egr-1; EC, endothelial cell. (B) Capillary branching morphogenesis is controlled by Snail. In P7–P8 mice, venous ECs in the superficial plexus start to extend capillary branching toward the deep retina in response to tissue needs. The sprouting ECs at the border between the GCL and IPL are exposed to ECM, which subsequently contributes to Snail induction and stabilization, followed by enhanced VEGFR3 expression. Snail/VEGFR3-expressing ECs vertically migrate toward deep retina. At P9–P11 mice, vertically migrating ECs reach in the boundary of INL and turn sideways to form the deep capillary plexus in the OPL region. Snail knockdown attenuates the initiation of EC sprouting, which subsequently impairs the formation of the deep capillary plexus.
Mentions: Findings from this study show that (a) Snail was induced in angiogenically activated ECs in the postnatal retinal vasculature via ECM signaling; (b) the Snail-Egr-1 complex upregulated VEGFR3 mRNA; and (c) Snail knockdown attenuated the formation of the deep vascular plexus by impairing vertical sprouting and affecting VEGFR3 expression. Collectively, the data demonstrate that a Snail-VEGFR3 axis contributed to the extension of capillary vessels and venous vessels (Fig 8).

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