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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.

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Related in: MedlinePlus

EPC-CM promotes HUVEC proliferation and migration.EPC-CM incubation significantly increased proliferation (A) and migration (B) of HUVEC in comparison to control medium. Blocking PDGFRβ with either a PDGFRβ neutralizing antibody or PDGF receptor kinase inhibitor (AG1296) offset the chemotactic and proliferative response of HUVEC to EPC-CM in both proliferation and migration. However, addition of recombinant human PDGF-BB at a similar content of EPC-CM (100 pg/ml) or 1000-times higher (100 ng/ml) was not able to promote significant proliferation or migration of HUVEC. *, P<0.0001; #, P<0.0001; **, P<0.05.
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pone-0014107-g001: EPC-CM promotes HUVEC proliferation and migration.EPC-CM incubation significantly increased proliferation (A) and migration (B) of HUVEC in comparison to control medium. Blocking PDGFRβ with either a PDGFRβ neutralizing antibody or PDGF receptor kinase inhibitor (AG1296) offset the chemotactic and proliferative response of HUVEC to EPC-CM in both proliferation and migration. However, addition of recombinant human PDGF-BB at a similar content of EPC-CM (100 pg/ml) or 1000-times higher (100 ng/ml) was not able to promote significant proliferation or migration of HUVEC. *, P<0.0001; #, P<0.0001; **, P<0.05.

Mentions: In vitro EPC-CM increased HUVEC proliferation 1.43±0.06 -fold (P<0.001) and EC migration along the cytokine gradient by a factor of 1.93±0.12 (P<0.001) as compared to controls (Figure 1A–1B). When EPC-CM was used but supplemented with the PDGFRβ neutralizing antibody AF385 migration of EC along the EPC-CM gradient was no longer different from controls (1.23±0.08, P = n.s.). Furthermore, HUVEC proliferation with EPC-CM in presence of the neutralizing antibody AF385 was decreased significantly (1.04±0.05, P = n.s.). Likewise, the treatment with PDGF-receptor kinase inhibitor AG1296 (1 µM) effectively damped the migration of HUVEC (1.25±0.04, P = n.s.) and attenuated the proliferation of HUVEC under EPC-CM culture (1.09±0.09, P = n.s.) (Figure 1A–1B).


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)

EPC-CM promotes HUVEC proliferation and migration.EPC-CM incubation significantly increased proliferation (A) and migration (B) of HUVEC in comparison to control medium. Blocking PDGFRβ with either a PDGFRβ neutralizing antibody or PDGF receptor kinase inhibitor (AG1296) offset the chemotactic and proliferative response of HUVEC to EPC-CM in both proliferation and migration. However, addition of recombinant human PDGF-BB at a similar content of EPC-CM (100 pg/ml) or 1000-times higher (100 ng/ml) was not able to promote significant proliferation or migration of HUVEC. *, P<0.0001; #, P<0.0001; **, P<0.05.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0014107-g001: EPC-CM promotes HUVEC proliferation and migration.EPC-CM incubation significantly increased proliferation (A) and migration (B) of HUVEC in comparison to control medium. Blocking PDGFRβ with either a PDGFRβ neutralizing antibody or PDGF receptor kinase inhibitor (AG1296) offset the chemotactic and proliferative response of HUVEC to EPC-CM in both proliferation and migration. However, addition of recombinant human PDGF-BB at a similar content of EPC-CM (100 pg/ml) or 1000-times higher (100 ng/ml) was not able to promote significant proliferation or migration of HUVEC. *, P<0.0001; #, P<0.0001; **, P<0.05.
Mentions: In vitro EPC-CM increased HUVEC proliferation 1.43±0.06 -fold (P<0.001) and EC migration along the cytokine gradient by a factor of 1.93±0.12 (P<0.001) as compared to controls (Figure 1A–1B). When EPC-CM was used but supplemented with the PDGFRβ neutralizing antibody AF385 migration of EC along the EPC-CM gradient was no longer different from controls (1.23±0.08, P = n.s.). Furthermore, HUVEC proliferation with EPC-CM in presence of the neutralizing antibody AF385 was decreased significantly (1.04±0.05, P = n.s.). Likewise, the treatment with PDGF-receptor kinase inhibitor AG1296 (1 µM) effectively damped the migration of HUVEC (1.25±0.04, P = n.s.) and attenuated the proliferation of HUVEC under EPC-CM culture (1.09±0.09, P = n.s.) (Figure 1A–1B).

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