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 HUVEC matrigel cord structure formation.EPC-CM incubation for 8 hours strikingly accelerated the formation of EC cord structures on growth factor reduced matrigel™ (B) as compared to control medium incubation (A). Antibody mediated PDGFRβ neutralization partially inhibited the EPC-CM accelerated cord structure formation (C). rhPDGF-BB conditioning of control medium in either 100 ng/ml (D) or 100 pg/ml (E) concentration did not have significant effect on promoting the formation of EC cord structures. The difference effect between groups was evidenced by both the number of spouts (F) and the total cord structure length (G). * and **, P<0.0001; # and ##, P<0.0001; ***, P<0.05.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2991332&req=5

pone-0014107-g002: Angiogenic potential of EPC-CM on HUVEC matrigel cord structure formation.EPC-CM incubation for 8 hours strikingly accelerated the formation of EC cord structures on growth factor reduced matrigel™ (B) as compared to control medium incubation (A). Antibody mediated PDGFRβ neutralization partially inhibited the EPC-CM accelerated cord structure formation (C). rhPDGF-BB conditioning of control medium in either 100 ng/ml (D) or 100 pg/ml (E) concentration did not have significant effect on promoting the formation of EC cord structures. The difference effect between groups was evidenced by both the number of spouts (F) and the total cord structure length (G). * and **, P<0.0001; # and ##, P<0.0001; ***, P<0.05.

Mentions: Consistently with the above findings, exposure of HUVEC to EPC-CM resulted in a significantly increased number and length of EC cord structures in growth factor reduced Matrigel™ as compared to control medium (56.63±3.56 vs. 12.88±2.36/HPF in sprout numbers, 5521±268.3 vs. 1636±1448.7 µm/HPF, P<0.0001). Again, blocking of PDGFRβ by AF385 caused partial inhibition of the EPC-CM effect (43.25±3.30/HPF in sprout numbers, 4338±170.2 µm/HPF; P<0.001 compared to EPC-CM group) whereas rhPDGF-BB supplementation of control medium did not increase the formation of endothelial cord structures in either the 100 pg/ml or the 100 ng/ml concentration (Figure 2).


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 HUVEC matrigel cord structure formation.EPC-CM incubation for 8 hours strikingly accelerated the formation of EC cord structures on growth factor reduced matrigel™ (B) as compared to control medium incubation (A). Antibody mediated PDGFRβ neutralization partially inhibited the EPC-CM accelerated cord structure formation (C). rhPDGF-BB conditioning of control medium in either 100 ng/ml (D) or 100 pg/ml (E) concentration did not have significant effect on promoting the formation of EC cord structures. The difference effect between groups was evidenced by both the number of spouts (F) and the total cord structure length (G). * and **, P<0.0001; # and ##, P<0.0001; ***, P<0.05.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0014107-g002: Angiogenic potential of EPC-CM on HUVEC matrigel cord structure formation.EPC-CM incubation for 8 hours strikingly accelerated the formation of EC cord structures on growth factor reduced matrigel™ (B) as compared to control medium incubation (A). Antibody mediated PDGFRβ neutralization partially inhibited the EPC-CM accelerated cord structure formation (C). rhPDGF-BB conditioning of control medium in either 100 ng/ml (D) or 100 pg/ml (E) concentration did not have significant effect on promoting the formation of EC cord structures. The difference effect between groups was evidenced by both the number of spouts (F) and the total cord structure length (G). * and **, P<0.0001; # and ##, P<0.0001; ***, P<0.05.
Mentions: Consistently with the above findings, exposure of HUVEC to EPC-CM resulted in a significantly increased number and length of EC cord structures in growth factor reduced Matrigel™ as compared to control medium (56.63±3.56 vs. 12.88±2.36/HPF in sprout numbers, 5521±268.3 vs. 1636±1448.7 µm/HPF, P<0.0001). Again, blocking of PDGFRβ by AF385 caused partial inhibition of the EPC-CM effect (43.25±3.30/HPF in sprout numbers, 4338±170.2 µm/HPF; P<0.001 compared to EPC-CM group) whereas rhPDGF-BB supplementation of control medium did not increase the formation of endothelial cord structures in either the 100 pg/ml or the 100 ng/ml concentration (Figure 2).

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