ABSTRACT
Title
Characterization of in vitro endothelial progenitor cell differenziation: role of mature endothelium and pharmacologically active microcarriers
Authors
C. Musilli
Doctorate School in Pharmacology and Toxicology
Laboratory of Cardiovascular Pharmacology, Department of Preclinical and Clinical Pharmacology - University of Florence, Italy.
Doctorate School in Pharmacology and Toxicology
Laboratory of Cardiovascular Pharmacology, Department of Preclinical and Clinical Pharmacology - University of Florence, Italy.
Abstract
Circulating endothelial progenitor cells (EPCs) have a key role in endothelium maintenance, since are implicated in both re-endothelialization and neovascularization, thus improving the function of ischemic organs, possibly by both induction or modulation of vasculogenesis and angiogenesis (1,2).However, the relationship between human EPCs and mature endothelial cells remain unclear. In this study the interactions between Human Coronary Artery Endothelial Cells (HCAECs) and Peripheral Blood Mononuclear Cells (PBMCs) during their early differentiation towards an EPC phenotype were investigated.A co-culture model, in which the two cell types share the same culture medium in the absence of any exogenous angiogenic stimulus, was used.A 3-day co-culture period with mature endothelial cells increased the expression of VEGF-R2, VE-cadherin, αvβ3- and α 5-integrin in PBMCs, assessed by cytofluorimetric analysis. The acquisition of an EPC phenotype in response to the co-culture was further confirmed by double staining of PBMCs for UEA-1 binding and acLDL uptake.These findings strongly suggest that mature endothelium may support the differentiation of PBMCs into EPC. ECP differentiation and viability was then studied by using pharmacologically active microparticles (PAM) as cell carriers. PAMs are microparticles polymers (poly D,L lactic coglicolic acid) biodegradable andbiocompatible coated with fibronectin and poly-D-lysine sequences(3). Firstly, adhesion experiments to PAM were performed. Data showed that EPCs were able to adhere to PAM within few hours and this adhesion was increased if PAM were further coated with fibronectin. Moreover, the adhesion to PAM was also correlated to the EPC phenotype. Pharmacologically active PAM, which release VEGF-A, increased the ability of EPC to adhere to them and strongly supported endothelial-like phenotype of cells.
References :
1. Asahara T et al., 1999; Circ Res 85: 221-228.
2. Kalka C. et al., 2000; Proc Natl Acad Sci USA 97: 3422-3427.
3.Tatard et al. 2005; Biomaterials 26(17):3727-37.
References :
1. Asahara T et al., 1999; Circ Res 85: 221-228.
2. Kalka C. et al., 2000; Proc Natl Acad Sci USA 97: 3422-3427.
3.Tatard et al. 2005; Biomaterials 26(17):3727-37.