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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

Gene expression during tubule formation. (A) VEGFR2, (B) VE-cadherin and (C) CD31 mean expression in assayed EPCs and ECs, relative to 60% confluent ECs (± SEM; n = 3). Dotted line indicates expression in 60% confluent EPCs. Significant differences between cell types indicated (*P < 0.05, **P < 0.01). CytB expression in (D) EPCs and (E) ECs, relative to 0 h. Columns with different letters are significantly different (P < 0.05).
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Figure 3: Gene expression during tubule formation. (A) VEGFR2, (B) VE-cadherin and (C) CD31 mean expression in assayed EPCs and ECs, relative to 60% confluent ECs (± SEM; n = 3). Dotted line indicates expression in 60% confluent EPCs. Significant differences between cell types indicated (*P < 0.05, **P < 0.01). CytB expression in (D) EPCs and (E) ECs, relative to 0 h. Columns with different letters are significantly different (P < 0.05).

Mentions: To determine whether tubule formation from EPCs and ECs was a function of endothelial-specific expression, we analyzed VEGFR2, VE-cadherin and CD31 expression. VEGFR2 expression increased in both cells from 0 h to 2 h, with a significantly greater level in EPCs at 0 h (P < 0.05) and 2 h (P < 0.01; Figure 3a) whilst maximal expression was observed at 2 h and 4 h for EPCs and ECs, respectively, followed by a progressive decrease. From 0 h to 6 h, ECs expressed significantly more VE-cadherin than EPCs and, following an initial decrease between 0 h and 2 h in EPCs, expression progressively increased up to 8 h (P < 0.05; Figure 3b). Expression in ECs reached its maximum by 4 h (P < 0.05) and then decreased from 4 h onwards whilst in EPCs this started at 8 h, there being no significant difference between EPCs and ECs from this point onwards. Expression of CD31 in EPCs increased from 0 h to 4 h (P < 0.05) followed by a reduction at 6 h (P < 0.05; Figure 3c). Conversely, CD31 expression in ECs decreased from 0 h to 4 h before increasing to its maximum at 6 h, whilst in EPCs maximal expression was observed at 8 h (P < 0.05). After 8 h, expression in both cell types decreased progressively.


Angiogenic potential of endothelial progenitor cells and embryonic stem cells.

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

Gene expression during tubule formation. (A) VEGFR2, (B) VE-cadherin and (C) CD31 mean expression in assayed EPCs and ECs, relative to 60% confluent ECs (± SEM; n = 3). Dotted line indicates expression in 60% confluent EPCs. Significant differences between cell types indicated (*P < 0.05, **P < 0.01). CytB expression in (D) EPCs and (E) ECs, relative to 0 h. Columns with different letters are significantly different (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Gene expression during tubule formation. (A) VEGFR2, (B) VE-cadherin and (C) CD31 mean expression in assayed EPCs and ECs, relative to 60% confluent ECs (± SEM; n = 3). Dotted line indicates expression in 60% confluent EPCs. Significant differences between cell types indicated (*P < 0.05, **P < 0.01). CytB expression in (D) EPCs and (E) ECs, relative to 0 h. Columns with different letters are significantly different (P < 0.05).
Mentions: To determine whether tubule formation from EPCs and ECs was a function of endothelial-specific expression, we analyzed VEGFR2, VE-cadherin and CD31 expression. VEGFR2 expression increased in both cells from 0 h to 2 h, with a significantly greater level in EPCs at 0 h (P < 0.05) and 2 h (P < 0.01; Figure 3a) whilst maximal expression was observed at 2 h and 4 h for EPCs and ECs, respectively, followed by a progressive decrease. From 0 h to 6 h, ECs expressed significantly more VE-cadherin than EPCs and, following an initial decrease between 0 h and 2 h in EPCs, expression progressively increased up to 8 h (P < 0.05; Figure 3b). Expression in ECs reached its maximum by 4 h (P < 0.05) and then decreased from 4 h onwards whilst in EPCs this started at 8 h, there being no significant difference between EPCs and ECs from this point onwards. Expression of CD31 in EPCs increased from 0 h to 4 h (P < 0.05) followed by a reduction at 6 h (P < 0.05; Figure 3c). Conversely, CD31 expression in ECs decreased from 0 h to 4 h before increasing to its maximum at 6 h, whilst in EPCs maximal expression was observed at 8 h (P < 0.05). After 8 h, expression in both cell types decreased progressively.

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