P3475Dabigatran inhibits the activation of endothelial progenitor cells induced by thrombin

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Papadaki ◽  
S Sidiropoulou ◽  
I Moschonas ◽  
A Tselepis
Keyword(s):  
Endothelial Cells ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Adhesion Molecule ◽  
Mononuclear Cells ◽  
Umbilical Vein ◽  
Cell Types ◽  
The European Union ◽  
Membrane Expression ◽  
Endothelial Progenitor

Abstract Introduction Thrombin is a coagulation serine protease, which also activates various cell types, including endothelial cells. Late-outgrowth endothelial cells (OECs) are a type of endothelial progenitor cells that contribute to endothelial regeneration and angiogenesis. Dabigatran is a direct oral anticoagulant that inhibits thrombin's action and is widely used in everyday clinical practice. Purpose We investigated the effect of dabigatran on thrombin-induced activation of OECs, using the membrane expression of adhesion molecule ICAM-1 as activation marker. Control experiments were conducted in mature human umbilical vein endothelial cells (HUVECs). Methods CD34+ cells were isolated from cord blood mononuclear cells, using human CD34 Microbead Kit and appropriately cultured for OEC formation. HUVECs were purchased from Lonza. Confluent OECs and HUVECs were incubated with 10 or 20 μM dabigatran for 10 min, before activation with 8 U/mL thrombin, for 24 h. The effect of dabigatran on ICAM-1 expression (anti-CD54-PE) was evaluated in both cell types as % gated CD31+/CD54+ cells, using flow cytometry. Results Thrombin induced ICAM-1 membrane expression by 33±15% on OECs and by 123±22% on HUVECs, compared with respective untreated cells (p<0.05 for both comparisons, from 6 different experiments). Dabigatran at 10 μM significantly inhibited ICAM-1 expression by 36±7% on OECs and 57±8% on HUVECs, as well as at 20 μM by 51±8% on OECs and 79±7% on HUVECs (p<0.05 for all comparisons, from 4 different experiments). Conclusions We show for the first time that dabigatran at concentrations relevant to those existing in vivo after oral administration, inhibits the thrombin-induced membrane expression of the adhesion molecule ICAM-1 on OECs, a phenomenon that is also observed on mature endothelial cells. The significance of this effect regarding the pathophysiological role of OECs and mature endothelial cells at the clinical level remains to be established. Acknowledgement/Funding Operational Program “Human Resources Development, Education and Lifelong Learning”. Co-financed by the European Union and Greek national funds

Presence of endothelial progenitor cells, distinct from mature endothelial cells, within human CD146+ blood cells

2005 ◽  
Vol 94 (12) ◽  
pp. 1270-1279 ◽  
Author(s):  
Bruno Delorme ◽  
Agnès Basire ◽  
Carla Gentile ◽  
Florence Sabatier ◽  
Frédéric Monsonis ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Network Formation ◽  
Mononuclear Cells ◽  
Circulating Endothelial Cells ◽  
Endothelial Progenitor ◽  
Color Flow ◽  
Immunodeficient Mice ◽  
Circulating Cells

SummaryCD146 is an adhesion molecule present on endothelial cells throughout the vascular tree. CD146 is also expressed by circulating endothelial cells (CECs) widely considered to be mature endothelial cells detached from injured vessels. The discovery of circulating endothelial progenitor cells (EPCs) originating from bone marrow prompted us to investigate whether CD146 circulating cells could also contains EPCs. We tested this hypothesis using an approach combining elimination of CECs by an adhesion step, followed by immunomagnetic sorting of remaining CD146+ cells from the non adherent fraction of cord blood mononuclear cells. When cultured under endothelial-promoting conditions, these cells differentiated as late outgrowth endothelial colonies: they grew as a cobblestone monolayer, were uniformly positive for endothelial markers and did not express leukocyte antigens. They highly proliferated and were expanded in long-term culture without alterations of their phenotypic and functional properties (DiI-ac-LDL uptake, wound repair, capillary-like network formation, and TNFα response). Moreover, these cells colonized a Matrigel plug in immunodeficient mice (NOD/SCID). Finally, using 4-color flow cytometry analysis of purified CD34+ cells, we clearly discriminated, CD146+ EPCs (CD146+ CD34+ CD45+ CD133+ or CD117+), and CD146+ CECs (CD146+ CD34+, CD45− CD133− or CD117−), both in cord and adult peripheral blood. The relative proportions of the two CD146+ subsets varied in patients with myocardial infarction as compared to healthy subjects. Our study establishes that, beside CECs, CD146+ circulating cells contain a subpopulation of EPCs with potential use in proangiogenic therapy. In addition, the dual measurement of CD146+ CECs and CD146+ EPCs offers a promising tool for monitoring vascular injury/regeneration processes in clinical situations.

Circulating Endothelial Progenitor Cells Are Increased in Patients with Myelofibrosis and Do Not Harbor V617F JAK-2 or W515L MPL Mutations

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1535-1535 ◽  
Author(s):  
Elisa Bonetti ◽  
Vittorio Rosti ◽  
Laura Villani ◽  
Rita Campanelli ◽  
Gaetano Bergamaschi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Healthy Subjects ◽  
Mononuclear Cells ◽  
Median Frequency ◽  
Endothelial Progenitor ◽  
Circulating Endothelial Progenitor Cells ◽  
Mutational Status

Abstract Bone marrow and spleen neoangiogenesis is a relevant feature of patients with myelofibrosis (MF). We have previously reported that patients with MF have an increased percentage of circulating endothelial progenitor cells (EPC) assessed as CD34+CD133+VEGFR2+ cells compared with patients with other Ph-negative myeloproliferative disorders (polycythemia vera, PV, and essential thrombocytemia, ET) and healthy subjects. However, neither the functional activity of these putative EPC nor their belonging to the malignant clone have been yet fully characterized. In order to address these issues we have grown in vitro EPC-derived colonies from the peripheral blood (PB) of 36 patients with MF, 9 patients with PV or ET and 10 healthy subjects. Seventeen MF patients harbored a V617F JAK-2 mutation (8 heterozygous and 9 homozygous) whereas 2 patients showed a W515L MPL mutation (both heterozygous). Eight out of 9 PV/ET patients had a V617F JAK-2 mutation (5 heterozygous and 3 homozygous). Mononuclear cells were cultured in collagen coated 6 well plates in the presence of EBM-2MV medium according to Ingram et al (Blood104:2752; 2004). The endothelial origin of the colonies was ascertained by assessment of the expression of CD105, CD146, CD144, CD31, vWf, VEGFR-2, CD14 and CD45 antigens. V617F JAK-2 and W515L MPL mutations were assessed by PCR, followed by enzymatic digestion, of endothelial cells after tripsinization of the EPC-derived colonies. The median frequency (number of colonies per 107 mononuclear cells plated) of EPC-derived colonies was statistically higher in MF patients (0.25, range 0–8.1) compared to healthy subjects (0.05, 0–0.3; P=0.037), but not different form that of PV/ET patients (0, 0–4.4; P=NS). Immunophenotyping confirmed that the cells expressed the endothelial antigens CD105, CD146, CD144, CD31, vWf, and VEGFR-2 but not the hematopoietic specific antigens CD45 and CD14. The capacity of colony-derived endothelial cells of MF patients to form capillary-like structures in the Matrigel assay was not different from that of healthy subjects. No correlation was found between the number of colonies and the mutational status of either JAK-2 or MPL. In 11 MF patients harboring either a JAK-2 (n=9) or a MPL (n=2) mutation, colony growth was observed and PCR was performed on EPC-derived colonies. In 0/9 and 0/2 cases neither JAK-2 nor MPL mutations were found, respectively. In addition, no V617F JAK-2 mutation was found in the EPC-derived colonies of 8 PV/ET patients who carried the mutation in their granulocytes. Taken together, our data show that patients with MF have an increased frequency of EPC in their PB compared to healthy subjects and that these mobilized EPC are not clonally-related to the JAK-2 or MPL mutated clone. Whether or not circulating EPC derive from an earlier progenitor cell compared to the one in which the JAK-2/MPL mutations arise remains to be determined.

Characterization of Angiogenic Potential of Late Endothelial Progenitor Cells on Human Cord Blood and Bone Marrow

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5404-5404
Author(s):  
Eun-Sun Yoo ◽  
Jee-Young Ahn ◽  
KiHwan Kwon ◽  
Soo-Ah Oh ◽  
Moon-Young Choi ◽  
...  
Keyword(s):  
Cord Blood ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Adhesion Molecule ◽  
Mononuclear Cells ◽  
Marker Genes ◽  
Endothelial Progenitor ◽  
Angiogenic Potential ◽  
Cell Based Therapy

Abstract Background: The identification of circulating endothelial progenitor cells (EPCs) has revolutionized approaches to cell-based therapy for injured and ischemic tissues. Recently, we have demonstrated that there are 2 distinct types of EPCs from UCB having different biologic properties for angiogenic capabilities in vitro and in vivo. In present study, the aim is to directly compare umbilical cord blood (UCB)- and BM-derived late EPC surface phenotypes and in vitro functional capacity. Methods: Mononuclear cells from UCB and BM cultured using EGM-2 medium with VEGF, IGF-1 and FGF for 21 days. Late outgrowing endothelail cells(late OECs) which were in peak growth at third weeks of culture were analyzed for expression of various surface markers by flow cytometry/RT-PCR/IF, tube formation in Matrigel plates, proliferation assay, endothelial colony assay and the role of SDF-1/VEGF on migration. Results: The adherent cells after culture of 7 days exhibited a fibroblast like shape in BM and a cobblestone shaped cells in UCB. Although two sources of OECs were comparable in expression of endothelial and various adhesion molecule markers, BM-derived OECs contained higher proportion of cells expressing smooth muscle cell markers(SMMHC), several adhesion molecule(CD49d, CD62L and VCAM-1), whereas the expression of CXCR-4, PECAM-1 and CD62E and expression of mRNA on endothelial marker genes were higher in UCB-derived OECs. UCB-OECS stained positive for uptake of acetylated low-density lipoprotein and had more migratory ability in the presence of SDF-1 and VEGF compared with BM-OECs. Both sources OECs effectively formed capillary tubes in Matrigel plates. Conclusion: We directly compared OECs derived from UCB and BM and two source of OECs differ in aspect of several adhesion molecule and angiogenic potential in vitro. These difference of UCB render it potentially advantageous for human therapeutic OECs applications for potential applications for a “cell therapy” in the situations on vascular injuries when compared with patients-derived BM.

Vessel wall–derived endothelial cells rapidly proliferate because they contain a complete hierarchy of endothelial progenitor cells

Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2783-2786 ◽  
Author(s):  
David A. Ingram ◽  
Laura E. Mead ◽  
Daniel B. Moore ◽  
Wayne Woodard ◽  
Amy Fenoglio ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cord Blood ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Ex Vivo ◽  
Umbilical Vein ◽  
Proliferative Potential ◽  
Endothelial Progenitor ◽  
Vessel Walls

AbstractEndothelial progenitor cells (EPCs) can be isolated from adult peripheral and umbilical cord blood and expanded exponentially ex vivo. In contrast, human umbilical vein endothelial cells (HUVECs) or human aortic endothelial cells (HAECs) derived from vessel walls are widely considered to be differentiated, mature endothelial cells (ECs). However, similar to adult- and cord blood–derived EPCs, HUVECs and HAECs derived from vessel walls can be passaged for at least 40 population doublings in vitro. Based on this paradox, we tested whether EPCs reside in HUVECs or HAECs utilizing a novel single cell deposition assay that discriminates EPCs based on their proliferative and clonogenic potential. We demonstrate that a complete hierarchy of EPCs can be identified in HUVECs and HAECs derived from vessel walls and discriminated by their clonogenic and proliferative potential. This study provides evidence that a diversity of EPCs exists in human vessels and provides a conceptual framework for determining both the origin and function of EPCs in maintaining vessel integrity.

Comparative Analysis of Methods for Assessment of Circulating Endothelial Progenitor Cells Indicated Heterogeneity of Subpopulations at Various Stages of Differentiation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4134-4134
Author(s):  
Varda R. Deutsch ◽  
Haim Shmilovich ◽  
Anastasia Abashidze ◽  
Hylton Miller ◽  
Gad Keren ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Comparative Analysis ◽  
Blood Vessels ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Mononuclear Cells ◽  
Therapeutic Potential ◽  
Proliferative Capacity ◽  
Endothelial Progenitor ◽  
Humoral Factors

Abstract The cells of the vasculature are derived from pluripotent stem cells, known as hemangioblasts, which also give rise to blood. Angiogenesis, the formation of new blood vessels is considered to result from the proliferation and migration of mature endothelial cells from existing blood vessels or from the recently described, but not yet well characterized endothelial progenitor cells (EPCs). The number and properties of EPC in disease states is of considerable interest due to the promising therapeutic potential of these cells. EPCs have been shown to be mobilized from the bone marrow and contribute to angiogenesis following vascular injury, organ ischaemia and tumor progression. However, mechanisms that drive the EPC response to injury remain elusive and the lack of definitions of EPC subpopulations and the many methods used by different groups to identify these cells make correlation of results difficult. To begin to understand the potential of these cells, we performed a comparative analysis of several methods used for circulating EPC assessment in 40 healthy individuals (mean age of 33±9 years) and correlated them with humoral factors known to influence their numbers. Peripheral blood mononuclear cells were obtained and evaluated by flow cytometeric analysis with antibodies to CD34, CD45, CD133 and KDR, and the remaining cells grown under endothelial cell conditions for assessment of colony forming unit (CFU) numbers and adhesive properties. Levels of circulating vascular endothelial growth factor (VEGF), erythropoietin and C-reactive protein were determined and correlated with each of the EPC markers. CFU numbers did not correlate with the number of CD34/KDR (VEGFR2) or CD34/CD133/KDR positive cells and negatively correlated with CD34/CD133 (which includes hematopoietic progenitors). CD34/KDR number correlated with CD34/CD133/KDR but not with CD34/CD133. Only the VEGFR2 positive cells populations (CD34/KDR and CD34/CD133/KDR) correlated with VEGF serum levels. The number of EPC adhering to fibronectin and endothelial-cells correlated with CFU numbers but not with EPC membrane markers. Our results indicate for the first time that EPC, like hematopoietic precursors may be a heterogeneous cell population comprised of progenitors at various stages of differentiation, having varied proliferative capacity. This could explain the lack of correlation in results obtained using different methods for quantitatively assessing the numbers of circulating EPC. These data also suggest that co-expression of CD34, CD133and KDR-VEGFR2 is appropriate for defining a population of circulating EPC whereas CFU are more likely to reflect the proliferative capacity of the progenitors.

In vivo vasculogenic potential of human blood-derived endothelial progenitor cells

Blood ◽  
2007 ◽  
Vol 109 (11) ◽  
pp. 4761-4768 ◽  
Author(s):  
Juan M. Melero-Martin ◽  
Zia A. Khan ◽  
Arnaud Picard ◽  
Xiao Wu ◽  
Sailaja Paruchuri ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Umbilical Vein ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Vascular Networks ◽  
Endothelial Progenitor ◽  
Immunodeficient Mice

Abstract Vascularization of tissues is a major challenge of tissue engineering (TE). We hypothesize that blood-derived endothelial progenitor cells (EPCs) have the required proliferative and vasculogenic activity to create vascular networks in vivo. To test this, EPCs isolated from human umbilical cord blood or from adult peripheral blood, and human saphenous vein smooth muscle cells (HSVSMCs) as a source of perivascular cells, were combined in Matrigel and implanted subcutaneously into immunodeficient mice. Evaluation of implants at one week revealed an extensive network of human-specific lumenal structures containing erythrocytes, indicating formation of functional anastomoses with the host vasculature. Quantitative analyses showed the microvessel density was significantly superior to that generated by human dermal microvascular endothelial cells (HDMECs) but similar to that generated by human umbilical vein endothelial cells (HUVECs). We also found that as EPCs were expanded in culture, their morphology, growth kinetics, and proliferative responses toward angiogenic factors progressively resembled those of HDMECs, indicating a process of in vitro maturation. This maturation correlated with a decrease in the degree of vascularization in vivo, which could be compensated for by increasing the number of EPCs seeded into the implants. Our findings strongly support the use of human EPCs to form vascular networks in engineered organs and tissues.

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