Limits...
Endothelial progenitor cells induce a phenotype shift in differentiated endothelial cells towards PDGF/PDGFRβ axis-mediated angiogenesis.

Wyler von Ballmoos M, Yang Z, Völzmann J, Baumgartner I, Kalka C, Di Santo S - PLoS ONE (2010)

Bottom Line: Conditioned medium from human EPC (EPC-CM) cultured in hypoxic conditions contained substantially higher levels of PDGF-BB as compared to normoxic conditions (P<0.01).All the pro-angiogenic effects of EPC-CM on HUVEC could be partially inhibited by inactivation of PDGFRβ (P<0.01).This finding may be utilized to enhance EPC-based therapy of ischemic tissue in future.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiac Surgery, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts, USA.

ABSTRACT

Background: Endothelial Progenitor Cells (EPC) support neovascularization and regeneration of injured endothelium both by providing a proliferative cell pool capable of differentiation into mature vascular endothelial cells and by secretion of angiogenic growth factors.

Objective: The aim of this study was to investigate the role of PDGF-BB and PDGFRβ in EPC-mediated angiogenesis of differentiated endothelial cells.

Methods and results: Conditioned medium from human EPC (EPC-CM) cultured in hypoxic conditions contained substantially higher levels of PDGF-BB as compared to normoxic conditions (P<0.01). EPC-CM increased proliferation (1.39-fold; P<0.001) and migration (2.13-fold; P<0.001) of isolated human umbilical vein endothelial cells (HUVEC), as well as sprouting of vascular structures from ex vivo cultured aortic rings (2.78-fold increase; P = 0.01). The capacity of EPC-CM to modulate the PDGFRβ expression in HUVEC was assessed by western blot and RT-PCR. All the pro-angiogenic effects of EPC-CM on HUVEC could be partially inhibited by inactivation of PDGFRβ (P<0.01). EPC-CM triggered a distinct up-regulation of PDGFRβ (2.5±0.5; P<0.05) and its phosphorylation (3.6±0.6; P<0.05) in HUVEC. This was not observed after exposure of HUVEC to recombinant human PDGF-BB alone.

Conclusion: These data indicate that EPC-CM sensitize endothelial cells and induce a pro-angiogenic phenotype including the up-regulation of PDGFRβ, thereby turning the PDGF/PDGFRβ signaling-axis into a critical element of EPC-induced endothelial angiogenesis. This finding may be utilized to enhance EPC-based therapy of ischemic tissue in future.

Show MeSH

Related in: MedlinePlus

Angiogenic potential of EPC-CM on ex vivo aortic ring assays.Incubation with EPC-CM (B) enhanced the formation of vascular outgrowth from 1 mm rat aortic ring embedded in growth factor reduced-Matrigel™ compared to control medium incubation (A). This enhanced EC cord structure outgrowth could be blocked by the addition of 1 µg/ml PDGFRβ antibody into EPC-CM (C). A similar vascular sprouting extent could only be observed by stimulation aortic ring with 100 ng/ml rhPDGF-BB (1000-times concentrated than the content in EPC-CM) (D), but not with the concentration at 100 pg/ml (E). The extents of vascular outgrowth were quantitatively analyzed and presented by the length of the sprouts (D). *, #, P<0.001.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2991332&req=5

pone-0014107-g003: Angiogenic potential of EPC-CM on ex vivo aortic ring assays.Incubation with EPC-CM (B) enhanced the formation of vascular outgrowth from 1 mm rat aortic ring embedded in growth factor reduced-Matrigel™ compared to control medium incubation (A). This enhanced EC cord structure outgrowth could be blocked by the addition of 1 µg/ml PDGFRβ antibody into EPC-CM (C). A similar vascular sprouting extent could only be observed by stimulation aortic ring with 100 ng/ml rhPDGF-BB (1000-times concentrated than the content in EPC-CM) (D), but not with the concentration at 100 pg/ml (E). The extents of vascular outgrowth were quantitatively analyzed and presented by the length of the sprouts (D). *, #, P<0.001.

Mentions: Furthermore, in the aortic ring assay, extensive sprouting occurred when the aortic rings were cultured in EPC-CM (145.93±7.69 vs. 52.48±9.76 µm in control, P<0.001; Figure 3B) and this sprouting was lowered in the presence of the PDGFRβ neutralizing antibody AF385 (59.78±7.99 µm, Figure 3C). A high-dose supplementation of control medium with rhPDGF-BB (100 ng/ml) showed results comparable to EPC-CM in this assay (133.95±11.66 µm, P<0.001; Figure 3D-E).


Endothelial progenitor cells induce a phenotype shift in differentiated endothelial cells towards PDGF/PDGFRβ axis-mediated angiogenesis.

Wyler von Ballmoos M, Yang Z, Völzmann J, Baumgartner I, Kalka C, Di Santo S - PLoS ONE (2010)

Angiogenic potential of EPC-CM on ex vivo aortic ring assays.Incubation with EPC-CM (B) enhanced the formation of vascular outgrowth from 1 mm rat aortic ring embedded in growth factor reduced-Matrigel™ compared to control medium incubation (A). This enhanced EC cord structure outgrowth could be blocked by the addition of 1 µg/ml PDGFRβ antibody into EPC-CM (C). A similar vascular sprouting extent could only be observed by stimulation aortic ring with 100 ng/ml rhPDGF-BB (1000-times concentrated than the content in EPC-CM) (D), but not with the concentration at 100 pg/ml (E). The extents of vascular outgrowth were quantitatively analyzed and presented by the length of the sprouts (D). *, #, P<0.001.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2991332&req=5

pone-0014107-g003: Angiogenic potential of EPC-CM on ex vivo aortic ring assays.Incubation with EPC-CM (B) enhanced the formation of vascular outgrowth from 1 mm rat aortic ring embedded in growth factor reduced-Matrigel™ compared to control medium incubation (A). This enhanced EC cord structure outgrowth could be blocked by the addition of 1 µg/ml PDGFRβ antibody into EPC-CM (C). A similar vascular sprouting extent could only be observed by stimulation aortic ring with 100 ng/ml rhPDGF-BB (1000-times concentrated than the content in EPC-CM) (D), but not with the concentration at 100 pg/ml (E). The extents of vascular outgrowth were quantitatively analyzed and presented by the length of the sprouts (D). *, #, P<0.001.
Mentions: Furthermore, in the aortic ring assay, extensive sprouting occurred when the aortic rings were cultured in EPC-CM (145.93±7.69 vs. 52.48±9.76 µm in control, P<0.001; Figure 3B) and this sprouting was lowered in the presence of the PDGFRβ neutralizing antibody AF385 (59.78±7.99 µm, Figure 3C). A high-dose supplementation of control medium with rhPDGF-BB (100 ng/ml) showed results comparable to EPC-CM in this assay (133.95±11.66 µm, P<0.001; Figure 3D-E).

Bottom Line: Conditioned medium from human EPC (EPC-CM) cultured in hypoxic conditions contained substantially higher levels of PDGF-BB as compared to normoxic conditions (P<0.01).All the pro-angiogenic effects of EPC-CM on HUVEC could be partially inhibited by inactivation of PDGFRβ (P<0.01).This finding may be utilized to enhance EPC-based therapy of ischemic tissue in future.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiac Surgery, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts, USA.

ABSTRACT

Background: Endothelial Progenitor Cells (EPC) support neovascularization and regeneration of injured endothelium both by providing a proliferative cell pool capable of differentiation into mature vascular endothelial cells and by secretion of angiogenic growth factors.

Objective: The aim of this study was to investigate the role of PDGF-BB and PDGFRβ in EPC-mediated angiogenesis of differentiated endothelial cells.

Methods and results: Conditioned medium from human EPC (EPC-CM) cultured in hypoxic conditions contained substantially higher levels of PDGF-BB as compared to normoxic conditions (P<0.01). EPC-CM increased proliferation (1.39-fold; P<0.001) and migration (2.13-fold; P<0.001) of isolated human umbilical vein endothelial cells (HUVEC), as well as sprouting of vascular structures from ex vivo cultured aortic rings (2.78-fold increase; P = 0.01). The capacity of EPC-CM to modulate the PDGFRβ expression in HUVEC was assessed by western blot and RT-PCR. All the pro-angiogenic effects of EPC-CM on HUVEC could be partially inhibited by inactivation of PDGFRβ (P<0.01). EPC-CM triggered a distinct up-regulation of PDGFRβ (2.5±0.5; P<0.05) and its phosphorylation (3.6±0.6; P<0.05) in HUVEC. This was not observed after exposure of HUVEC to recombinant human PDGF-BB alone.

Conclusion: These data indicate that EPC-CM sensitize endothelial cells and induce a pro-angiogenic phenotype including the up-regulation of PDGFRβ, thereby turning the PDGF/PDGFRβ signaling-axis into a critical element of EPC-induced endothelial angiogenesis. This finding may be utilized to enhance EPC-based therapy of ischemic tissue in future.

Show MeSH
Related in: MedlinePlus