Potential role of activated platelets in homing of human endothelial progenitor cells to subendothelial matrix

2006 ◽  
Vol 96 (10) ◽  
pp. 498-504 ◽  
Author(s):  
Eli Lev ◽  
Zeev Estrov ◽  
Khatira Aboulfatova ◽  
David Harris ◽  
Juan Granada ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Vascular Injury ◽  
Tissue Injury ◽  
Platelet Rich Plasma ◽  
Flow Conditions ◽  
Endothelial Progenitor ◽  
Activated Platelets ◽  
Static Conditions

SummaryEndothelial progenitor cells (EPCs) mobilize from the bone marrow in response to tissue injury and participate in vascular repair. However, there is limited data about the homing mechanisms of EPCs to vascular injury sites. Recently animal experiments indicated that platelets playa role in recruitment of EPCs to injury sites. However, data on the possible interaction between platelets and EPCs within the human system are limited. We, therefore, examined in-vitro human platelet-EPC interaction under static and flow conditions. Human EPCs were isolated from donated buffy coats by magnetic microbeads and flow cytometry cell sorting using CD133 and VEGFR-2, respectively, as markers. Platelets were tested in the form of washed platelets, platelet rich plasma or whole blood. EPCs formed heterotypic aggregates with resting platelets under static conditions, an interaction that was greatly enhanced when platelets were activated by collagen, ADP or thrombin-activation peptide. The platelet-EPC interaction was inhibited by antibodies to P-selectin or P-selectin glycoprotein ligand-1 (PSGL-1), but not by antibodies to glycoproteins Ib-IX-V or IIb/IIIa. When perfused over activated platelets under shear stress of 2.5 dyn/cm2, EPCs tethered to platelayers and either adhered immediately or rolled a short distance before adhering. In addition, platelets promoted the colonization of adherent EPCs in culture conditions. Consistent with recent animal studies, these findings demonstrate that human EPCs interact in vitro with activated platelets under static and flow conditions, mediated through P-selectin–PSGL-1 interaction. This interaction may be a central mechanism for homing of EPCs to vascular injury sites.

Role of Platelets in Homing of Endothelial Progenitor Cells to the Site of Vascular Injury.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3681-3681
Author(s):  
Eli I. Lev ◽  
Zeev Estrov ◽  
Khatira Aboulfatova ◽  
David Harris ◽  
Juan F. Granada ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Vascular Injury ◽  
Bone Marrow Cells ◽  
Tissue Injury ◽  
Platelet Rich Plasma ◽  
Flow Conditions ◽  
Endothelial Progenitor ◽  
Activated Platelets

Abstract Endothelial Progenitor Cells (EPCs) are undifferentiated bone marrow cells that are rapidly mobilized upon vascular or tissue injury. The circulating EPCs home to and differentiate at the site of vessel injury to enhance repair of damaged endothelium. Much has been learnt of how EPCs adhere to and transmigrate on endothelial cells during angiogenesis, but little is know about how EPCs home to the site where endothelial cells are denuded and subendothelium is exposed following vascular injury. We hypothesized that platelets mediate EPC homing because they are the first cells that tether and adhere to subendothelium exposed by vascular injury. To test this hypothesis, we examined the platelet-EPC interaction under static and flow conditions. Human EPCs were purified from buffy coats by cell sorting using CD133 and VEGFR-2 as the cell markers. The EPCs were then incubated with washed platelets that were either at resting state or activated by 5 mg/ml of collagen. EPC-platelet interaction was measured in the form of heterotypic aggregation between two types of cells by flow cytometry (dual labeled with FITC-CD42a and PE-CD133). We found the EPCs attached to resting platelets, however, the percentage of platelets binding to EPCs significantly increased when platelets were activated by collagen (1.02% vs. 2.76%, p < 0.05). EPC-platelet aggregation was similarly detected in whole blood and platelet-rich plasma. When perfused over a monolayer of activated platelets under a shear stress of 2.5 dyn/cm2, the CD133 positive EPCs tethered to the platelet monolayer. The tethered EPCs either firmly adhered immediately or rolled a short distance before becoming adherent. This EPC-platelet interaction was calcium-dependent and inhibited by up to 60±11.5% by a polyclonal P-selectin antibody. In comparison, the monoclonal GP Iba antibody AK2, which blocks GP Ib-VWF interaction, had no effect. These results demonstrate for the first time a significant interaction between EPCs and activated platelets both at static and flow conditions. Our findings suggest that platelets may function as carrier cells that direct EPCs to the site of vascular injury. In addition to homing, platelets, which release several growth factors known to affect EPCs, may provide a supporting matrix on which adherent EPCs proliferate and differentiate.

scholarly journals ID: 1016 Production of endothelial progenitor cells from skin fibroblasts by direct reprogramming for clinical usages

2017 ◽  
Vol 4 (S) ◽  
pp. 91
Author(s):  
Phuc Van Pham ◽  
Ngoc Bich Vu ◽  
Thuy Thi-Thanh Dao ◽  
Ha Thi-Ngan Le ◽  
Lan Thi Phi ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Platelet Rich Plasma ◽  
Autologous Transplantation ◽  
Direct Conversion ◽  
Dermal Fibroblasts ◽  
Skin Fibroblasts ◽  
Direct Reprogramming ◽  
Endothelial Progenitor

Endothelial progenitor cells (EPCs) play an important role in angiogenesis. However, they exist in limited numbers in the human body. This study was aimed to produce EPCs, for autologous transplantation, using direct reprogramming of skin fibroblasts under GMP-compliant conditions. Fibroblasts were collected and cultured from the skin in DMEM/F12 medium supplemented with 5% activated platelet-rich plasma and 1% antibiotic-antimycotic solution. They were then transfected with mRNA ETV2 and incubated in culture medium under hypoxia (5% oxygen) for 14 d. Phenotype analysis of transfected cells confirmed that single-factor ETV2 transfection successfully reprogrammed dermal fibroblasts into functional EPCs. Our results showed that ETV2 mRNA combined with hypoxia can give rise to functional EPCs. The cells exhibited functional phenotypes similar to endothelial cells derived from umbilical cord vein; they expressed CD31 and VEGFR2, and formed capillary-like structures in vitro. Moreover, these EPCs could significantly improve hindlimb ischemia in mouse models. Although the direct conversion efficacy was low (3.12 ± 0.98%), altogether our study demonstrates that functional EPCs can be produced from fibroblasts and can be used in clinical applications.

Gene transfer of endothelial NO-synthase restores migratory capacity of endothelial progenitor cells from patients with coronary artery diseases

2007 ◽  
Vol 30 (4) ◽  
pp. 96
Author(s):  
Michael R. Ward ◽  
Qiuwang Zhang ◽  
Duncan J. Stewart ◽  
Michael J.B. Kutryk
Keyword(s):  
Risk Factors ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Fold Increase ◽  
No Synthase ◽  
Endothelial Progenitor ◽  
Migratory Capacity ◽  
Acute Mi ◽  
Cad Risk

Autologous endothelial progenitor cells (EPCs) have been used extensively in the development of cell-based therapy for acute MI. However, EPCs isolated from patients with CAD and/or CAD risk factors have reduced regenerative activity compared to cells from healthy subjects. As in endothelial cells, endothelial NO synthase (eNOS) expression and subsequent NO production are believed to be critical determinants of EPC function. Recently, the ability of EPCs to migrate in vitro in response to chemotactic stimuli has been shown to predict their regenerative capacity in clinical studies. Therefore, we hypothesized that the regenerative function of EPCs from patients with or at high risk for CAD will be enhanced by overexpression of eNOS, as assessed by migratory capacity. Methods: EPCs were isolated from the blood of human subjects with CAD risk factors (>15% Framingham risk score; FRS) (± CAD) by Ficoll gradient separation and differential culture. Following 3 days in culture, cells were transduced using lentivirus vectors containing either eNOS or GFP (sham) at an MOI of 3. The cells were cultured for an additional 5 days before being used in functional assays. Cell migration and chemotaxis in response to VEGF (50 ng/mL) and SDF-1 (100 ng/mL) were assessed using a modified Boyden Chamber assay. Results: Transduction at an MOI of 3 led to a ~90-100-fold increase in eNOS mRNA expression and a 5-6 fold increase in eNOS protein expression, as assessed by qRT-PCR and Western Blotting. Moreover, there was a significant improvement in the migration of EPCs following eNOS transduction compared to sham-transduced EPCs in response to both VEGF (44.3 ± 8.4 vs. 31.1 ± 4.6 cells/high power field; n=10, p < 0.05) and SDF-1 (51.9 ± 11.1 vs. 34.5 ± 3.3 cells/HPF; n=10, p < 0.05). Conclusions: These data show that the reduced migration capacity of EPCs isolated from patients with CAD and/or CAD risk factors can be significantly improved through eNOS overexpression in these cells. Thus, eNOS transduction of autologous EPCs may enhance their ability to restore myocardial perfusion and function following acute MI. We intend to further explore the regenerative potential of eNOS-transduced EPCs using various in vitro and in vivo models.

scholarly journals Effective Actions of Ion Release from Mesoporous Bioactive Glass and Macrophage Mediators on the Differentiation of Osteoprogenitor and Endothelial Progenitor Cells

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1152
Author(s):  
Alberto Polo-Montalvo ◽  
Laura Casarrubios ◽  
María Concepción Serrano ◽  
Adrián Sanvicente ◽  
María José Feito ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Mesoporous Structure ◽  
Ion Release ◽  
Endothelial Progenitor ◽  
Matrix Mineralization ◽  
Intracellular Content

Due to their specific mesoporous structure and large surface area, mesoporous bioactive glasses (MBGs) possess both drug-delivery ability and effective ionic release to promote bone regeneration by stimulating osteogenesis and angiogenesis. Macrophages secrete mediators that can affect both processes, depending on their phenotype. In this work, the action of ion release from MBG-75S, with a molar composition of 75SiO2-20CaO-5P2O5, on osteogenesis and angiogenesis and the modulatory role of macrophages have been assessed in vitro with MC3T3-E1 pre-osteoblasts and endothelial progenitor cells (EPCs) in monoculture and in coculture with RAW 264.7 macrophages. Ca2+, phosphorous, and silicon ions released from MBG-75S were measured in the culture medium during both differentiation processes. Alkaline phosphatase activity and matrix mineralization were quantified as the key markers of osteogenic differentiation in MC3T3-E1 cells. The expression of CD31, CD34, VEGFR2, eNOS, and vWF was evaluated to characterize the EPC differentiation into mature endothelial cells. Other cellular parameters analyzed included the cell size and complexity, intracellular calcium, and intracellular content of the reactive oxygen species. The results obtained indicate that the ions released by MBG-75S promote osteogenesis and angiogenesis in vitro, evidencing a macrophage inhibitory role in these processes and demonstrating the high potential of MBG-75S for the preparation of implants for bone regeneration.

scholarly journals Interleukin-1β Augments Angiogenic Responses of Murine Endothelial Progenitor Cells in Vitro

2009 ◽  
Vol 29 (5) ◽  
pp. 933-943 ◽  
Author(s):  
Anna Rosell ◽  
Ken Arai ◽  
Josephine Lok ◽  
Tongrong He ◽  
Shuzhen Guo ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Mononuclear Cells ◽  
Therapeutic Angiogenesis ◽  
Interleukin 1Β ◽  
Endothelial Progenitor ◽  
Angiogenic Potential ◽  
Diphenyl Tetrazolium Bromide ◽  
In Vitro Angiogenesis

Endothelial progenitor cells (EPCs) may provide novel opportunities for therapeutic angiogenesis after ischemic diseases. However, it is unclear how the angiogenic potential of EPCs might be affected by an inflammatory environment. We examine how the potent cytokine interleukin-1β (IL-1β) affects angiovasculogenic responses in EPCs in culture. Mononuclear cells isolated from mouse spleen were plated on fibronectin-coated wells and grown in EGM-2 MV media. Endothelial progenitor cells were phenotyped using multiple markers (UEA-Lectin, ac-LDL, CD133, CD34, vWillebrand Factor, Flk-1) and to identify the IL-1 Receptor-I. We quantified cell and colony counts and performed MTT (3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide) and Matrigel assays, in vitro, under control and IL-1β (10 ng/mL) conditions. Endothelial progenitor cells exposed to IL-1β increased in the number of cells and colonies compared with untreated cells, without any effect on cell metabolic integrity. Furthermore, IL-1β treatment augmented EPC angiogenic function, significantly increasing the number of vessel-like structures in the Matrigel assay. An early phosphorylation of ERK1/2 occurred after IL-1β stimulation, and this pathway was inhibited if IL-1 Receptor-I was blocked. Our results suggest that IL-1β is a potent stimulator of in vitro angiogenesis through ERK signaling in mouse EPCs. Further studies are warranted to assess how interactions between proinflammatory environments and EPC responses may be leveraged to enhance therapeutic angiogenesis.

Abstract 3955: Chemokines Fused to a Fractalkine Backbone and a GPI-Anchor Attract Embryonic Endothelial Progenitor Cells to the Site of Ischemia

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Chiraz El-Aouni ◽  
Franziska Globisch ◽  
Achim Pfosser ◽  
Georg Stachel ◽  
Rabea Hinkel ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Adhesion Molecule ◽  
Capillary Density ◽  
Gpi Anchor ◽  
Endothelial Progenitor ◽  
Collateral Growth ◽  
Artificial Adhesion

Recruitment of endothelial progenitor cells to the sites of ischemia is a prerequisite for efficient therapeutic neovascularization via vasculogenesis. Chemokines play a major role in the homing of EPCs at the ischemic vasculature, a mechanism fading in chronic ischemia. To overcome this limitation, we constructed an artificial adhesion molecule consisting of a GPI-anchor, a fractalkine-backbone and an SDF-1 head (SDF-1-fra-GPI), which was applied for enhanced recruitment of embryonic EPCs (eEPCs: CXCR4++, Tie2++, Thrombomodulin++, CD34-, MHCI-, vWF inducible, eNOS inducible) in vitro and in vivo . Methods: In a flow chamber adhesion assay, Control plasmids (pcDNA or GPI-SDF-1 cDNA) were compared to the SDF-1-fra-GPI construct for eEPC recruitment 24h after liposomal transfection of rat endothelial cells. In vivo, in rabbits (n=5 per group) at day 7 (d7) after femoral artery excision, 1 mg of the SDF-1-fra-GPI or eGFP cDNA was transfected into the ischemic limb. At d9, ischemic hindlimbs were retroinfused with 5x10 6 eEPCs. Angiography was performed for collateral quantification and frame count score at d9 and d37 (% of d9), capillary density was assessed via PECAM-1-staining (capillaries/muscle fiber = c/mf). Results: In vitro, eEPC adhesion (16±12 cells/field) was increased to a higher extent by SDF-1-fra-GPI (79±13) than SDF1-GPI (54±8) or control vector (37±8). In vivo , eEPC adhesion in the ischemic hindlimb after SDF-1-fra-GPI transfection compared to mock transfection (30±3 vs. 9±1 cells/field). Whereas capillary density was unaffected (1.66±0.30 SDF-1-Fra-GPI vs. 1.56±0.29 eEPCs), collateral growth (152±10% SDF-1-fra-GPI vs. 124±13%) as well as perfusion score (198±17% SDF-1-fra-GPI vs.160±6% eEPCs) further increased after SDF-1-fra-GPI transfection (controls: 1.24±0.12 c/mf, collaterals 105±8%, perfusion score 112±11%). We conclude that recruitment of EPCs expressing CXCR4 (the SDF-1 receptor) may benefit from pre-treatment of the recipient vasculature with SDF-1-Fra-GPI, an artificial adhesion molecule. This approach might be valuable for enhancing EPC recruitment in the scenario of therapeutic neovascular-ization of chronic ischemic syndromes.

Sign in / Sign up

Export Citation Format

Share Document