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N-cadherin acts upstream of VE-cadherin in controlling vascular morphogenesis.

Luo Y, Radice GL - J. Cell Biol. (2005)

Bottom Line: Contrary to previous studies, we found that N-cadherin localizes to endothelial cell-cell junctions in addition to its well-known diffusive membrane expression.Loss of N-cadherin in endothelial cells results in embryonic lethality at mid-gestation due to severe vascular defects.Intriguingly, loss of N-cadherin caused a significant decrease in VE-cadherin and its cytoplasmic binding partner, p120ctn.

View Article: PubMed Central - PubMed

Affiliation: Center for Research on Reproduction and Women's Health, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.

ABSTRACT
Endothelial cells express two classic cadherins, VE-cadherin and N-cadherin. The importance of VE-cadherin in vascular development is well known; however, the function of N-cadherin in endothelial cells remains poorly understood. Contrary to previous studies, we found that N-cadherin localizes to endothelial cell-cell junctions in addition to its well-known diffusive membrane expression. To investigate the role of N-cadherin in vascular development, N-cadherin was specifically deleted from endothelial cells in mice. Loss of N-cadherin in endothelial cells results in embryonic lethality at mid-gestation due to severe vascular defects. Intriguingly, loss of N-cadherin caused a significant decrease in VE-cadherin and its cytoplasmic binding partner, p120ctn. The down-regulation of both VE-cadherin and p120ctn was confirmed in cultured endothelial cells using small interfering RNA to knockdown N-cadherin. We also show that N-cadherin is important for endothelial cell proliferation and motility. These findings provide a novel paradigm by which N-cadherin regulates angiogenesis, in part, by controlling VE-cadherin expression at the cell membrane.

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Endothelial cell behavior is regulated by N-cadherin. Quantification of BrdU incorporation and Ki-67 immunostaining in HUVEC after transfection with control (con), VE-cadherin (VE), or N-cadherin (N) siRNA (A). Quantification of EC migration using a transwell cell invasiveness assay after transfection with control, VE-cadherin, or N-cadherin siRNA (B). Western analysis of β1-integrin expression after transfection with control, VE-cadherin, or N-cadherin siRNA (C). Bar graphs (B and C) were normalized to control. White lines indicate that intervening lanes have been spliced out. Data represent the average for three independent knockdown experiments.
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fig5: Endothelial cell behavior is regulated by N-cadherin. Quantification of BrdU incorporation and Ki-67 immunostaining in HUVEC after transfection with control (con), VE-cadherin (VE), or N-cadherin (N) siRNA (A). Quantification of EC migration using a transwell cell invasiveness assay after transfection with control, VE-cadherin, or N-cadherin siRNA (B). Western analysis of β1-integrin expression after transfection with control, VE-cadherin, or N-cadherin siRNA (C). Bar graphs (B and C) were normalized to control. White lines indicate that intervening lanes have been spliced out. Data represent the average for three independent knockdown experiments.

Mentions: We observed fewer cell numbers 24 h after knockdown of N-cadherin compared with control, or VE-cadherin knockdown. No significant increase in apoptosis was observed after transfection of the N-cadherin siRNA (unpublished data). Therefore, we examined cellular proliferation in HUVEC cultures. We found that knockdown of N-cadherin caused a significant growth arrest by BrdU incorporation and Ki67 labeling (50% reduction in proliferation rate compared with control; Fig. 5 A). The growth inhibitory effect was attributed to loss of N-cadherin, rather than a decrease in VE-cadherin, because VE-cadherin knockdown alone had no effect on cellular proliferation. Hence, a decrease in EC proliferation may be responsible, at least in part, for the lack of vascular development in the N-cadherin CKO embryos.


N-cadherin acts upstream of VE-cadherin in controlling vascular morphogenesis.

Luo Y, Radice GL - J. Cell Biol. (2005)

Endothelial cell behavior is regulated by N-cadherin. Quantification of BrdU incorporation and Ki-67 immunostaining in HUVEC after transfection with control (con), VE-cadherin (VE), or N-cadherin (N) siRNA (A). Quantification of EC migration using a transwell cell invasiveness assay after transfection with control, VE-cadherin, or N-cadherin siRNA (B). Western analysis of β1-integrin expression after transfection with control, VE-cadherin, or N-cadherin siRNA (C). Bar graphs (B and C) were normalized to control. White lines indicate that intervening lanes have been spliced out. Data represent the average for three independent knockdown experiments.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2171890&req=5

fig5: Endothelial cell behavior is regulated by N-cadherin. Quantification of BrdU incorporation and Ki-67 immunostaining in HUVEC after transfection with control (con), VE-cadherin (VE), or N-cadherin (N) siRNA (A). Quantification of EC migration using a transwell cell invasiveness assay after transfection with control, VE-cadherin, or N-cadherin siRNA (B). Western analysis of β1-integrin expression after transfection with control, VE-cadherin, or N-cadherin siRNA (C). Bar graphs (B and C) were normalized to control. White lines indicate that intervening lanes have been spliced out. Data represent the average for three independent knockdown experiments.
Mentions: We observed fewer cell numbers 24 h after knockdown of N-cadherin compared with control, or VE-cadherin knockdown. No significant increase in apoptosis was observed after transfection of the N-cadherin siRNA (unpublished data). Therefore, we examined cellular proliferation in HUVEC cultures. We found that knockdown of N-cadherin caused a significant growth arrest by BrdU incorporation and Ki67 labeling (50% reduction in proliferation rate compared with control; Fig. 5 A). The growth inhibitory effect was attributed to loss of N-cadherin, rather than a decrease in VE-cadherin, because VE-cadherin knockdown alone had no effect on cellular proliferation. Hence, a decrease in EC proliferation may be responsible, at least in part, for the lack of vascular development in the N-cadherin CKO embryos.

Bottom Line: Contrary to previous studies, we found that N-cadherin localizes to endothelial cell-cell junctions in addition to its well-known diffusive membrane expression.Loss of N-cadherin in endothelial cells results in embryonic lethality at mid-gestation due to severe vascular defects.Intriguingly, loss of N-cadherin caused a significant decrease in VE-cadherin and its cytoplasmic binding partner, p120ctn.

View Article: PubMed Central - PubMed

Affiliation: Center for Research on Reproduction and Women's Health, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.

ABSTRACT
Endothelial cells express two classic cadherins, VE-cadherin and N-cadherin. The importance of VE-cadherin in vascular development is well known; however, the function of N-cadherin in endothelial cells remains poorly understood. Contrary to previous studies, we found that N-cadherin localizes to endothelial cell-cell junctions in addition to its well-known diffusive membrane expression. To investigate the role of N-cadherin in vascular development, N-cadherin was specifically deleted from endothelial cells in mice. Loss of N-cadherin in endothelial cells results in embryonic lethality at mid-gestation due to severe vascular defects. Intriguingly, loss of N-cadherin caused a significant decrease in VE-cadherin and its cytoplasmic binding partner, p120ctn. The down-regulation of both VE-cadherin and p120ctn was confirmed in cultured endothelial cells using small interfering RNA to knockdown N-cadherin. We also show that N-cadherin is important for endothelial cell proliferation and motility. These findings provide a novel paradigm by which N-cadherin regulates angiogenesis, in part, by controlling VE-cadherin expression at the cell membrane.

Show MeSH