Ed on the basis of their proliferation properties. Data are mean6SD derived from six independent experiments. doi:10.1371/journal.pone.0056377.gCD14 and CD45 resulted negative. In addition, FISH analysis, performed by using centromeric enumeration probes, allowed to demonstrate a normal diploid chromosomal pattern in the in vitro expanded EPC/ECFC (Figure 3C).Immuno-phenotype and subcloning potential of EPC/ ECFCAfter isolation from the ACS PBMC and ex-vivo expansion, primary EPC/ECFC 1655472 colonies were trypsinized and assessed for: i) their immuno-phenotype, by multi-colors flow cytometry (Figure 4) as well as for ii) clonogenic potential capacity, by single cells subculturing (Figure 5). As documented in Figure 4A, EPC/ECFC colonies were characterized by a variable expression of the CD34 antigen, ranging from 20-75 among the different cell samples. Moreover, a 4-colors flow cytometric analysis showed that viablecells from EPC/ECFC colonies were CD45 negative and by gating on cultured CD34+/CD45-/7-AAD- EPC/ECFC, the expression of CD105, CD31 and CD146 resulted uniformly positive (Figure 4B). On the other hand, EPC/ECFC were always negative for CD90, CD117 and CD133, while the expression of CD106 and CD184 was variable (data not shown). To evaluate the clonogenic potential of EPC/ECFC, a single cell plating (Figure 5A) was performed and the resulting clones were assigned to one of the established classes in agreement with the SIS3 site description of Barrandon Green [28]: i) large rapidly growing colonies were defined “holoclones”, ii) colonies characterized by limited growth were defined “paraclones”, iii) colonies showing intermediate features were defined “meroclones”. As result of these analyses, after sub-cloning we calculated a mean clonogenic output of 38.2618.5 clones/single primary EPC/Endothelial Progenitor Cells in ACS PatientsECFC seeded, with a prevalence of paraclones with respect to meraclones and holoclones (Figure 5B).DiscussionRevascularization of tissue following a cardiac infarct is one of the aims of conventional therapy and EPC have been widely studied as a potential MedChemExpress PS 1145 source of cell-based therapy for several cardiovascular disorders [29?4]. Although putative EPC have been commonly identified and enumerated by flow cytometry, even though without a standardized immunophenotyic approach, few studies have attempted to relate the in vitro isolation and expansion of PB-derived EPC to the immunophenotye of putative circulating EPC, and even less information is available about the clonogenic potential of the different endothelial subpopulations. To date, the potential use of EPC/ECFC for cell therapy purposes, especially in cardiovascular diseases, is unclear and many questions concerning the characteristics of these cells are still unresolved. Considering that it is universally accepted that the progenitor cells are defined by their clonogenic expansion capacity, we have undertook this study in order to better highlight EPC/ECFC immunophenotypic and clonogenic properties in patients affected by cardiovascular diseases, as a first essential step to explore the possibility to use these cells in a clinical autologous setting. Obviously, a suitable criterium to isolate and obtain EPC/ ECFC is needed and could enhance and address our knowledge for subsequent studies. In this respect, we were able to demonstrate for the first time that, after the initial peak of circulating EPC/ECFC described within the first 3 hours after inhospital.Ed on the basis of their proliferation properties. Data are mean6SD derived from six independent experiments. doi:10.1371/journal.pone.0056377.gCD14 and CD45 resulted negative. In addition, FISH analysis, performed by using centromeric enumeration probes, allowed to demonstrate a normal diploid chromosomal pattern in the in vitro expanded EPC/ECFC (Figure 3C).Immuno-phenotype and subcloning potential of EPC/ ECFCAfter isolation from the ACS PBMC and ex-vivo expansion, primary EPC/ECFC 1655472 colonies were trypsinized and assessed for: i) their immuno-phenotype, by multi-colors flow cytometry (Figure 4) as well as for ii) clonogenic potential capacity, by single cells subculturing (Figure 5). As documented in Figure 4A, EPC/ECFC colonies were characterized by a variable expression of the CD34 antigen, ranging from 20-75 among the different cell samples. Moreover, a 4-colors flow cytometric analysis showed that viablecells from EPC/ECFC colonies were CD45 negative and by gating on cultured CD34+/CD45-/7-AAD- EPC/ECFC, the expression of CD105, CD31 and CD146 resulted uniformly positive (Figure 4B). On the other hand, EPC/ECFC were always negative for CD90, CD117 and CD133, while the expression of CD106 and CD184 was variable (data not shown). To evaluate the clonogenic potential of EPC/ECFC, a single cell plating (Figure 5A) was performed and the resulting clones were assigned to one of the established classes in agreement with the description of Barrandon Green [28]: i) large rapidly growing colonies were defined “holoclones”, ii) colonies characterized by limited growth were defined “paraclones”, iii) colonies showing intermediate features were defined “meroclones”. As result of these analyses, after sub-cloning we calculated a mean clonogenic output of 38.2618.5 clones/single primary EPC/Endothelial Progenitor Cells in ACS PatientsECFC seeded, with a prevalence of paraclones with respect to meraclones and holoclones (Figure 5B).DiscussionRevascularization of tissue following a cardiac infarct is one of the aims of conventional therapy and EPC have been widely studied as a potential source of cell-based therapy for several cardiovascular disorders [29?4]. Although putative EPC have been commonly identified and enumerated by flow cytometry, even though without a standardized immunophenotyic approach, few studies have attempted to relate the in vitro isolation and expansion of PB-derived EPC to the immunophenotye of putative circulating EPC, and even less information is available about the clonogenic potential of the different endothelial subpopulations. To date, the potential use of EPC/ECFC for cell therapy purposes, especially in cardiovascular diseases, is unclear and many questions concerning the characteristics of these cells are still unresolved. Considering that it is universally accepted that the progenitor cells are defined by their clonogenic expansion capacity, we have undertook this study in order to better highlight EPC/ECFC immunophenotypic and clonogenic properties in patients affected by cardiovascular diseases, as a first essential step to explore the possibility to use these cells in a clinical autologous setting. Obviously, a suitable criterium to isolate and obtain EPC/ ECFC is needed and could enhance and address our knowledge for subsequent studies. In this respect, we were able to demonstrate for the first time that, after the initial peak of circulating EPC/ECFC described within the first 3 hours after inhospital.
