In Vitro Characterization of Circulating Endothelial Progenitor Cells Isolated From Patients With Acute Coronary Syndrome

PLoS One. 2013;8(2):e56377. doi: 10.1371/journal.pone.0056377. Epub 2013 Feb 11.


Background: The current understanding of the functional characteristics of circulating endothelial progenitor cells (EPC) is limited, especially in patients affected by cardiovascular diseases. In this study, we have analyzed the in vitro clonogenic capacity of circulating EPC, also known as endothelial colony-forming cells (ECFC), in patients with acute coronary syndrome (ACS), in comparison to the colony forming unit-endothelial-like cells (CFU-EC) of hematopoietic/monocytic origin.

Methodology/principal findings: By culturing peripheral blood mononuclear cells (PBMC) of patients with ACS (n = 70), CFU-EC were frequently isolated (from 77% of ACS patients), while EPC/ECFC were obtained only in a small subset (13%) of PBMC samples, all harvested between 7-14 days after the acute cardiovascular event. Notably, ex-vivo generation of EPC/ECFC was correlated to a higher in vitro release of PDGF-AA by the corresponding ACS patient PBMC. By using specific endothelial culture media, EPC/ECFC displayed in vitro expansion capacity, allowing the phenotypic and functional characterization of the cells. Indeed, after expansion, EPC/ECFC exhibited a normal diploid chromosomal setting by FISH analysis and an immunophenotype characterized by: i) uniform positivity for the expression of CD105, CD31, CD146 and Factor VIII, i) variable expression of the CD34, CD106 and CD184 markers, and iii) negativity for CD45, CD90, CD117 and CD133. Of interest, in single-cell replanting assays EPC/ECFC exhibited clonogenic expansion capacity, forming secondary colonies characterized by variable proliferation capacities.

Conclusion/significance: Our data indicate that a careful characterization of true EPC is needed in order to design future studies in the clinical autologous setting of patients with ACS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AC133 Antigen
  • Acute Coronary Syndrome / blood*
  • Acute Coronary Syndrome / pathology
  • Aged
  • Antigens, CD / metabolism
  • Antigens, CD34 / metabolism
  • Cell Culture Techniques
  • Cell Separation
  • Cytokines / metabolism
  • Endothelial Cells / cytology*
  • Endothelial Cells / metabolism
  • Female
  • Glycoproteins / metabolism
  • Humans
  • Leukocytes, Mononuclear / cytology
  • Male
  • Peptides / metabolism
  • Phenotype
  • Stem Cells / cytology*
  • Vascular Endothelial Growth Factor Receptor-1 / metabolism


  • AC133 Antigen
  • Antigens, CD
  • Antigens, CD34
  • Cytokines
  • Glycoproteins
  • PROM1 protein, human
  • Peptides
  • Vascular Endothelial Growth Factor Receptor-1

Grant support

This work was supported by Regione Emilia Romagna- Programma di Ricerca Medicina Rigenerativa, Regione—Università 2007/2009. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.