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Angiogenic potential of endothelial progenitor cells and embryonic stem cells.

Rae PC, Kelly RD, Egginton S, St John JC - (2011)

Bottom Line: We also described the production of highly angiogenic EPC-comparable cells from pluripotent embryonic stem cells (ESCs) by direct differentiation using EC-conditioned medium (ECCM).ECCM-treated ESC-derived progenitor cells exhibited angiogenic potential, demonstrated by in vitro tubule formation, and endothelial-specific gene expression equivalent to natural EPCs.We concluded the effect of EPCs is cumulative and beneficial, relying on upregulation of the angiogenic activity of transplanted cells combined with an increase in proliferative cell number to produce significant effects upon transplantation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, UK. justin.stjohn@monash.edu.

ABSTRACT

Background: Endothelial progenitor cells (EPCs) are implicated in a range of pathological conditions, suggesting a natural therapeutic role for EPCs in angiogenesis. However, current angiogenic therapies involving EPC transplantation are inefficient due to rejection of donor EPCs. One solution is to derive an expanded population of EPCs from stem cells in vitro, to be re-introduced as a therapeutic transplant. To demonstrate the therapeutic potential of EPCs we performed in vitro transplantation of EPCs into endothelial cell (EC) tubules using a gel-based tubule formation assay. We also described the production of highly angiogenic EPC-comparable cells from pluripotent embryonic stem cells (ESCs) by direct differentiation using EC-conditioned medium (ECCM).

Results: The effect on tubule complexity and longevity varied with transplantation quantity: significant effects were observed when tubules were transplanted with a quantity of EPCs equivalent to 50% of the number of ECs originally seeded on to the assay gel but not with 10% EPC transplantation. Gene expression of the endothelial markers VEGFR2, VE-cadherin and CD31, determined by qPCR, also changed dynamically during transplantation. ECCM-treated ESC-derived progenitor cells exhibited angiogenic potential, demonstrated by in vitro tubule formation, and endothelial-specific gene expression equivalent to natural EPCs.

Conclusions: We concluded the effect of EPCs is cumulative and beneficial, relying on upregulation of the angiogenic activity of transplanted cells combined with an increase in proliferative cell number to produce significant effects upon transplantation. Furthermore, EPCs derived from ESCs may be developed for use as a rapidly-expandable alternative for angiogenic transplantation therapy.

No MeSH data available.


Related in: MedlinePlus

Angiogenic potential of EPCs and ECs. Tubule formation of (A) EPCs and (B) ECs quantified by node counting. Presented as mean node number ± SEM (n = 3); *P < 0.05 vs. EPC nodes at same time-point. (C): Branch measurements, as mean length per mm2 ± SEM (n = 3); †P < 0.05, ††P < 0.01 vs. EPC branch length at same time-point.
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Figure 2: Angiogenic potential of EPCs and ECs. Tubule formation of (A) EPCs and (B) ECs quantified by node counting. Presented as mean node number ± SEM (n = 3); *P < 0.05 vs. EPC nodes at same time-point. (C): Branch measurements, as mean length per mm2 ± SEM (n = 3); †P < 0.05, ††P < 0.01 vs. EPC branch length at same time-point.

Mentions: To determine whether EPCs and ECs possessed angiogenic potential, and were thus able to form endothelial tubules, we cultured both cell types individually on ECMatrix gel for 14 h. Tubule formation was quantified by node counting and branch length measurement. The mean number of each node type at each time-point throughout the assay was similar for EPCs and ECs (P > 0.05; Figure 2a and 2b, respectively). A large number of N1 nodes was observed at 2 h, decreasing as the assay progressed, resulting in the formation of more N2 and N3 nodes and thus more complex structures. These were maximal at 4 h and 6 h, respectively for both cell lines. After 6 h, the number of N2 and N3 nodes decreased and they were last evident between 10 h and 12 h. Nevertheless, this gave rise to the formation of more complex structures, N4 nodes, which were first observed at 4 h for both EPCs and ECs and reached a maximum at 6 h and persisted until 8 h (ECs) and 10 h (EPCs) (P < 0.05). In turn, the most complex nodal formation (N5+) was first evident in EPC colonies between 6 to 8 h whilst ECs did not produce these structures. However, no tubule networks were observed after 12 h for either EPCs or ECs. The pattern of tubule formation indicated by branch length measurement was also similar for EPCs and ECs (Figure 2c). Mean length increased for both cell types from 0 to 6 h with maximal branch length being at 6 h, although mean length of EPC tubules at 6 h was significantly greater (P < 0.01). Nevertheless, mean branch length then decreased with significantly lower length being observed for ECs at 8 h (P < 0.05) when compared to EPCs. Thereafter, mean branch length continued to decrease for both cell types.


Angiogenic potential of endothelial progenitor cells and embryonic stem cells.

Rae PC, Kelly RD, Egginton S, St John JC - (2011)

Angiogenic potential of EPCs and ECs. Tubule formation of (A) EPCs and (B) ECs quantified by node counting. Presented as mean node number ± SEM (n = 3); *P < 0.05 vs. EPC nodes at same time-point. (C): Branch measurements, as mean length per mm2 ± SEM (n = 3); †P < 0.05, ††P < 0.01 vs. EPC branch length at same time-point.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108917&req=5

Figure 2: Angiogenic potential of EPCs and ECs. Tubule formation of (A) EPCs and (B) ECs quantified by node counting. Presented as mean node number ± SEM (n = 3); *P < 0.05 vs. EPC nodes at same time-point. (C): Branch measurements, as mean length per mm2 ± SEM (n = 3); †P < 0.05, ††P < 0.01 vs. EPC branch length at same time-point.
Mentions: To determine whether EPCs and ECs possessed angiogenic potential, and were thus able to form endothelial tubules, we cultured both cell types individually on ECMatrix gel for 14 h. Tubule formation was quantified by node counting and branch length measurement. The mean number of each node type at each time-point throughout the assay was similar for EPCs and ECs (P > 0.05; Figure 2a and 2b, respectively). A large number of N1 nodes was observed at 2 h, decreasing as the assay progressed, resulting in the formation of more N2 and N3 nodes and thus more complex structures. These were maximal at 4 h and 6 h, respectively for both cell lines. After 6 h, the number of N2 and N3 nodes decreased and they were last evident between 10 h and 12 h. Nevertheless, this gave rise to the formation of more complex structures, N4 nodes, which were first observed at 4 h for both EPCs and ECs and reached a maximum at 6 h and persisted until 8 h (ECs) and 10 h (EPCs) (P < 0.05). In turn, the most complex nodal formation (N5+) was first evident in EPC colonies between 6 to 8 h whilst ECs did not produce these structures. However, no tubule networks were observed after 12 h for either EPCs or ECs. The pattern of tubule formation indicated by branch length measurement was also similar for EPCs and ECs (Figure 2c). Mean length increased for both cell types from 0 to 6 h with maximal branch length being at 6 h, although mean length of EPC tubules at 6 h was significantly greater (P < 0.01). Nevertheless, mean branch length then decreased with significantly lower length being observed for ECs at 8 h (P < 0.05) when compared to EPCs. Thereafter, mean branch length continued to decrease for both cell types.

Bottom Line: We also described the production of highly angiogenic EPC-comparable cells from pluripotent embryonic stem cells (ESCs) by direct differentiation using EC-conditioned medium (ECCM).ECCM-treated ESC-derived progenitor cells exhibited angiogenic potential, demonstrated by in vitro tubule formation, and endothelial-specific gene expression equivalent to natural EPCs.We concluded the effect of EPCs is cumulative and beneficial, relying on upregulation of the angiogenic activity of transplanted cells combined with an increase in proliferative cell number to produce significant effects upon transplantation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, UK. justin.stjohn@monash.edu.

ABSTRACT

Background: Endothelial progenitor cells (EPCs) are implicated in a range of pathological conditions, suggesting a natural therapeutic role for EPCs in angiogenesis. However, current angiogenic therapies involving EPC transplantation are inefficient due to rejection of donor EPCs. One solution is to derive an expanded population of EPCs from stem cells in vitro, to be re-introduced as a therapeutic transplant. To demonstrate the therapeutic potential of EPCs we performed in vitro transplantation of EPCs into endothelial cell (EC) tubules using a gel-based tubule formation assay. We also described the production of highly angiogenic EPC-comparable cells from pluripotent embryonic stem cells (ESCs) by direct differentiation using EC-conditioned medium (ECCM).

Results: The effect on tubule complexity and longevity varied with transplantation quantity: significant effects were observed when tubules were transplanted with a quantity of EPCs equivalent to 50% of the number of ECs originally seeded on to the assay gel but not with 10% EPC transplantation. Gene expression of the endothelial markers VEGFR2, VE-cadherin and CD31, determined by qPCR, also changed dynamically during transplantation. ECCM-treated ESC-derived progenitor cells exhibited angiogenic potential, demonstrated by in vitro tubule formation, and endothelial-specific gene expression equivalent to natural EPCs.

Conclusions: We concluded the effect of EPCs is cumulative and beneficial, relying on upregulation of the angiogenic activity of transplanted cells combined with an increase in proliferative cell number to produce significant effects upon transplantation. Furthermore, EPCs derived from ESCs may be developed for use as a rapidly-expandable alternative for angiogenic transplantation therapy.

No MeSH data available.


Related in: MedlinePlus