CD34+ enriched cell products intended for autologous transendocardial CD34+ cell transplantation release significant amounts of angiopoietin-1

Abstract Objectives Cell-based therapy has emerged as a promising strategy for the treatment of patients with heart failure. Increasing evidence supports the hypothesis that paracrine mechanisms mediated by soluble factors released by the cells play a predominate role in reparative processes. The aim of our study was to analyze which cytokines are released by CD34 + enriched cell products intended for autologous transendocardial CD34 + cell transplantation in patients with cardiomyopathy. Material and methods The peripheral blood CD34 + cells from 12 patients were mobilized with granulocyte colony-stimulating factor, collected via apheresis and enriched by immunoselection. Results In CD34 + enriched cell population, hematopoietic, but not mesenchymal or endothelial, progenitors were detected. Except for angiopoietin-1, other measured cytokines (FGF1, FGF2, VEGF, PDGF, IL-6, HGH, SDF-1α/CXCL12, NRG1) were not released by CD34 + cells. The average concentration of angiopoietin-1 released by 5 × 10 6 CD34 + cells grown in neutral DMEM medium was 213.6 ± 130.0 pg/mL (range: 74–448 pg/mL). Angiopoietin-1 secretion correlated well with CD34 + cell's capacity for generating colonies derived from hematopoietic progenitors (Pearson's correlation = 0.964; P Conclusion Our study presents angiopoietin-1 as an interesting candidate and suggests future studies to explore how its release by CD34 + cells might impact the success of autologous CD34 + cell transplantation.