Limits...
A deficiency of uPAR alters endothelial angiogenic function and cell morphology.

Balsara RD, Merryman R, Virjee F, Northway C, Castellino FJ, Ploplis VA - (2011)

Bottom Line: This study focuses on the effect of uPAR deficiency (uPAR-/-) on angiogenic function and associated cytoskeletal organization.VEGF-enriched Matrigel implants from uPAR-/- mice demonstrated a lack of mature vessel formation compared to WT mice.Collectively, these results indicate that a uPAR deficiency leads to decreased angiogenic functions of endothelial cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: W, M, Keck Center for Transgene Research, University of Notre Dame, 230 Raclin-Carmichael Hall, Notre Dame, Indiana 46556, USA. vploplis@nd.edu.

ABSTRACT
The angiogenic potential of a cell requires dynamic reorganization of the cytoskeletal architecture that involves the interaction of urokinase-type plasminogen activator receptor (uPAR) with the extracellular matrix. This study focuses on the effect of uPAR deficiency (uPAR-/-) on angiogenic function and associated cytoskeletal organization. Utilizing murine endothelial cells, it was observed that adhesion, migration, proliferation, and capillary tube formation were altered in uPAR-/- cells compared to wild-type (WT) cells. On a vitronectin (Vn) matrix, uPAR-/- cells acquired a "fried egg" morphology characterized by circular actin organization and lack of lamellipodia formation. The up-regulation of β1 integrin, FAK(P-Tyr925), and paxillin (P-Tyr118), and decreased Rac1 activation, suggested increased focal adhesions, but delayed focal adhesion turnover in uPAR-/- cells. This accounted for the enhanced adhesion, but attenuated migration, on Vn. VEGF-enriched Matrigel implants from uPAR-/- mice demonstrated a lack of mature vessel formation compared to WT mice. Collectively, these results indicate that a uPAR deficiency leads to decreased angiogenic functions of endothelial cells.

No MeSH data available.


Related in: MedlinePlus

uPAR-/- ECs exhibited altered proliferation on Vn: (A) WT and uPAR-/- ECs were seeded on Vn-coated plates at a density of 1 × 105 cells/ml as described. Graph represents total cell counts measured at 24 and 48 hr (mean ± SEM) of three independent assays. At both time points proliferation of uPAR-/- ECs was significantly diminished compared to WT cells. p values between WT and uPAR-/- ECs at both time points were <0.05. (B) Proliferation of WT and uPAR-/- ECs is similar on collagen-coated plates at 24 and 48 hr.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3105951&req=5

Figure 3: uPAR-/- ECs exhibited altered proliferation on Vn: (A) WT and uPAR-/- ECs were seeded on Vn-coated plates at a density of 1 × 105 cells/ml as described. Graph represents total cell counts measured at 24 and 48 hr (mean ± SEM) of three independent assays. At both time points proliferation of uPAR-/- ECs was significantly diminished compared to WT cells. p values between WT and uPAR-/- ECs at both time points were <0.05. (B) Proliferation of WT and uPAR-/- ECs is similar on collagen-coated plates at 24 and 48 hr.

Mentions: The proliferative ability of uPAR-/- ECs plated on Vn (Figure 3A) was decreased compared to WT cells, but not when plated on collagen (Figure 3B) at 24 and 48 hr. On Vn-coated plates, WT cell counts increased by ~3-fold from its initial plating density of 1 × 105 cells at 24 hr compared to uPAR-/- ECs. At 48 hr the uPAR-/- cell counts have marginally increased compared to WT cells on Vn-coated plates. The slight decrease in WT cell counts at 48 hr when Vn is utilized as the matrix could be attributed to a functional plasminogen activation system. Since the proliferation is a long-term assay, it is possible that proteolysis of Vn could lead to cell detachment. Therefore, while adhesion of uPAR-/- cells on Vn and collagen was increased, the migratory and proliferative properties of the cells were only affected when the cells were plated on Vn, and not on collagen.


A deficiency of uPAR alters endothelial angiogenic function and cell morphology.

Balsara RD, Merryman R, Virjee F, Northway C, Castellino FJ, Ploplis VA - (2011)

uPAR-/- ECs exhibited altered proliferation on Vn: (A) WT and uPAR-/- ECs were seeded on Vn-coated plates at a density of 1 × 105 cells/ml as described. Graph represents total cell counts measured at 24 and 48 hr (mean ± SEM) of three independent assays. At both time points proliferation of uPAR-/- ECs was significantly diminished compared to WT cells. p values between WT and uPAR-/- ECs at both time points were <0.05. (B) Proliferation of WT and uPAR-/- ECs is similar on collagen-coated plates at 24 and 48 hr.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3105951&req=5

Figure 3: uPAR-/- ECs exhibited altered proliferation on Vn: (A) WT and uPAR-/- ECs were seeded on Vn-coated plates at a density of 1 × 105 cells/ml as described. Graph represents total cell counts measured at 24 and 48 hr (mean ± SEM) of three independent assays. At both time points proliferation of uPAR-/- ECs was significantly diminished compared to WT cells. p values between WT and uPAR-/- ECs at both time points were <0.05. (B) Proliferation of WT and uPAR-/- ECs is similar on collagen-coated plates at 24 and 48 hr.
Mentions: The proliferative ability of uPAR-/- ECs plated on Vn (Figure 3A) was decreased compared to WT cells, but not when plated on collagen (Figure 3B) at 24 and 48 hr. On Vn-coated plates, WT cell counts increased by ~3-fold from its initial plating density of 1 × 105 cells at 24 hr compared to uPAR-/- ECs. At 48 hr the uPAR-/- cell counts have marginally increased compared to WT cells on Vn-coated plates. The slight decrease in WT cell counts at 48 hr when Vn is utilized as the matrix could be attributed to a functional plasminogen activation system. Since the proliferation is a long-term assay, it is possible that proteolysis of Vn could lead to cell detachment. Therefore, while adhesion of uPAR-/- cells on Vn and collagen was increased, the migratory and proliferative properties of the cells were only affected when the cells were plated on Vn, and not on collagen.

Bottom Line: This study focuses on the effect of uPAR deficiency (uPAR-/-) on angiogenic function and associated cytoskeletal organization.VEGF-enriched Matrigel implants from uPAR-/- mice demonstrated a lack of mature vessel formation compared to WT mice.Collectively, these results indicate that a uPAR deficiency leads to decreased angiogenic functions of endothelial cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: W, M, Keck Center for Transgene Research, University of Notre Dame, 230 Raclin-Carmichael Hall, Notre Dame, Indiana 46556, USA. vploplis@nd.edu.

ABSTRACT
The angiogenic potential of a cell requires dynamic reorganization of the cytoskeletal architecture that involves the interaction of urokinase-type plasminogen activator receptor (uPAR) with the extracellular matrix. This study focuses on the effect of uPAR deficiency (uPAR-/-) on angiogenic function and associated cytoskeletal organization. Utilizing murine endothelial cells, it was observed that adhesion, migration, proliferation, and capillary tube formation were altered in uPAR-/- cells compared to wild-type (WT) cells. On a vitronectin (Vn) matrix, uPAR-/- cells acquired a "fried egg" morphology characterized by circular actin organization and lack of lamellipodia formation. The up-regulation of β1 integrin, FAK(P-Tyr925), and paxillin (P-Tyr118), and decreased Rac1 activation, suggested increased focal adhesions, but delayed focal adhesion turnover in uPAR-/- cells. This accounted for the enhanced adhesion, but attenuated migration, on Vn. VEGF-enriched Matrigel implants from uPAR-/- mice demonstrated a lack of mature vessel formation compared to WT mice. Collectively, these results indicate that a uPAR deficiency leads to decreased angiogenic functions of endothelial cells.

No MeSH data available.


Related in: MedlinePlus