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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

An uPAR deficiency alters cell adhesion to Vn and collagen: (A) uPAR deficiency promotes EC adhesion to Vn as observed by enhanced adhesion of uPAR-/- ECs compared to WT cells. WT and uPAR-/- cells on BSA serve as a control for this assay. (B) Enhanced adhesion of uPAR-/- ECs on collagen at 4 hr. (C) Adhesion of uPAR-/- ECs is similar to WT cells when plated on fibronectin. BSA served as a negative control matrix. The cell counts represent the mean ± SEM of three independent assays each performed in triplicate (40× field). Significance levels (*) indicates p value of < 0.05 between WT and uPAR-/- ECs.
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Figure 1: An uPAR deficiency alters cell adhesion to Vn and collagen: (A) uPAR deficiency promotes EC adhesion to Vn as observed by enhanced adhesion of uPAR-/- ECs compared to WT cells. WT and uPAR-/- cells on BSA serve as a control for this assay. (B) Enhanced adhesion of uPAR-/- ECs on collagen at 4 hr. (C) Adhesion of uPAR-/- ECs is similar to WT cells when plated on fibronectin. BSA served as a negative control matrix. The cell counts represent the mean ± SEM of three independent assays each performed in triplicate (40× field). Significance levels (*) indicates p value of < 0.05 between WT and uPAR-/- ECs.

Mentions: The ability of ECs to adhere to the ECM and reorganize their cell morphology is a critical step in angiogenesis [26]. uPAR has been implicated in pathological angiogenesis [9] and, due to the ability of the receptor to functionally interact with ECM [27], integrins [28,29], and G-protein-coupled receptors [30], uPAR can facilitate different angiogenic events. WT and uPAR-/- ECs were utilized to study the processes associated with angiogenesis, i.e., adhesion, migration, and proliferation. It was observed that uPAR-/- ECs adhered more strongly on Vn and collagen compared to WT cells (Figure 1A,B). uPAR-/- ECs displayed markedly increased adhesion on Vn, which peaked at 4 hr, but was statistically significant even after 24 hr (Figure 1A). However, adhesion of uPAR-/- ECs to fibronectin was unaffected (Figure 1C).


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

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

An uPAR deficiency alters cell adhesion to Vn and collagen: (A) uPAR deficiency promotes EC adhesion to Vn as observed by enhanced adhesion of uPAR-/- ECs compared to WT cells. WT and uPAR-/- cells on BSA serve as a control for this assay. (B) Enhanced adhesion of uPAR-/- ECs on collagen at 4 hr. (C) Adhesion of uPAR-/- ECs is similar to WT cells when plated on fibronectin. BSA served as a negative control matrix. The cell counts represent the mean ± SEM of three independent assays each performed in triplicate (40× field). Significance levels (*) indicates p value of < 0.05 between WT and uPAR-/- ECs.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: An uPAR deficiency alters cell adhesion to Vn and collagen: (A) uPAR deficiency promotes EC adhesion to Vn as observed by enhanced adhesion of uPAR-/- ECs compared to WT cells. WT and uPAR-/- cells on BSA serve as a control for this assay. (B) Enhanced adhesion of uPAR-/- ECs on collagen at 4 hr. (C) Adhesion of uPAR-/- ECs is similar to WT cells when plated on fibronectin. BSA served as a negative control matrix. The cell counts represent the mean ± SEM of three independent assays each performed in triplicate (40× field). Significance levels (*) indicates p value of < 0.05 between WT and uPAR-/- ECs.
Mentions: The ability of ECs to adhere to the ECM and reorganize their cell morphology is a critical step in angiogenesis [26]. uPAR has been implicated in pathological angiogenesis [9] and, due to the ability of the receptor to functionally interact with ECM [27], integrins [28,29], and G-protein-coupled receptors [30], uPAR can facilitate different angiogenic events. WT and uPAR-/- ECs were utilized to study the processes associated with angiogenesis, i.e., adhesion, migration, and proliferation. It was observed that uPAR-/- ECs adhered more strongly on Vn and collagen compared to WT cells (Figure 1A,B). uPAR-/- ECs displayed markedly increased adhesion on Vn, which peaked at 4 hr, but was statistically significant even after 24 hr (Figure 1A). However, adhesion of uPAR-/- ECs to fibronectin was unaffected (Figure 1C).

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