Nox2 siRNA Transfection Down Regulates VEGF Induced-Angiogenesis on Endothelial Progenitor Cells Which Are Derived From HCB

Abstract Abstract 5188 Background: Reactive oxygen species (ROS) such as superoxide and H2O2 have roles signaling for molecules on angiogenesis. NADPH oxidase Nox2 (gp91phox) is a major source of ROS. Previous, we had found that Nox2-based NADPH oxidase (gp91phox)-induced ROS may play important roles on EPCs migration and proliferation by VEGF (Blood. 2009;114:Abstract 1445). In the present study, we studied the impact of down-regulation of Nox2 on intracellular ROS level, proliferation, transmigration, and in vitro tube formation of HCB derived EPCs via Nox2 siRNA transfection. Methods: Outgrowing endothelial progenitor cells were established from mononuclear cells of human cord blood (Yoo et al, Stem cells. 2003;21:228-235) using EGM-2 media in a fibronectin-coated dish. EPCs were transfected with HiPerFection transfection reagent plus Nox2 siRNA or non-targeting control siRNA and cultured for 5 hours. 100ng/ml of VEGF was added to the transfected cells and cultured for overnight. Expression of Nox2 and pERK in the Nox2 siRNA transfected EPCs were detected by western blot analysis. Intracellular ROS level was analyzed by staining with 2, 7-dichlrodihydro-fluorescein-diacetate (H2DCF-DA) and flow cytometry. Transmigration against VEGF was performed using transwell system (Costar) and in vitro tube formation was assayed using In vitro angiogenesis kit (Chemicon). Results: Intracellular ROS level was increased during endothelial progenitor cell culture which were derived from HCB by VEGF treatment. Proliferation, in vitro tube formation matrigel assay and migration assay on endothelial progenitor cells using VEGF were decreased with Nox2 siRNA transfection when compared with that of control group. In western blot data, Nox2-based NADPH oxidase (gp91phox) was increased by VEGF and decreased by Nox2 siRNA transfection. VEGF induced pERK expression was also decreased by Nox2 siRNA transfection as well. Conclusions: Based on our studies, Nox2-based NADPH oxidase (gp91phox)-induced ROS may have important roles on proliferation in HCB induced EPCs by VEGF stimulation. Furthermore, Nox2 siRNA transfection into HCB derived EPC down-regulated intracellular ROS production and pERK expression. Our data may be useful finding the new therapeutic targets for ischemic heart and ischemic limb diseases by manipulating the level of intracellular ROS via Nox2. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Reactive Oxygen Species Might Have Important Roles On Angiogenesis of Endothelial Progenitor Cells Derived From HCB(Human Cord Blood) Which Are Stimulated by VEGF.

Blood ◽

10.1182/blood.v114.22.1445.1445 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1445-1445

Author(s):

Eun-Sun Yoo ◽

Yeung-Chul Mun ◽

Kyoung-Eun Lee ◽

Eunmi Nam ◽

Jee-Young Ahn ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Nadph Oxidase ◽

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Reactive Oxygen ◽

Tube Formation ◽

Control Group ◽

Oxygen Species ◽

Endothelial Progenitor

Abstract Abstract 1445 Poster Board I-468 Purpose VEGF is a key angiogenic growth factor stimulating proliferation, migration, and tube formation on endothelial cells (ECs), that works through the VEGF receptor type 2 (VEGR2, KDR/Flk1). Reactive oxygen species (ROS) such as superoxide and H2O2 have roles signaling for molecules on angiogenesis. In present study, the aim is to investigate the roles of reactive oxygen species on neovascularization in endothelial progenitor cells. Methods Mononuclear cells isolated from UCB were cultured using EGM-2 medium with VEGF, IGF-1 and FGF or basal medium in presence or absence of VEGF for 7 days. Outgrowing endothelail progenitor cells (Yoo et al, STEM CELLS 21:228-235, 2003) at first week of culture were analyzed ROS production by dichlorofluorescein (DCF) fluorescence by use of 2,7-dichlorodihydro-fluoresceine-diacetate (H2DCF-DA). In order to determine that ROS production might involve in EPC proliferation and migration, we had analyzed the impact of N-acetyl-L-cysteine (NAC), broad spectrum ROS scavenger, and NAD(P)H oxidase inhibitor, diphenylene iodonium (DPI) using the proliferation, in vitro tube formation matrigel assay, migration assay with SDF-1/VEGF. We also analyzed the expression of NOX2-based NADPH oxidase (gp91phox) and activation of ERK2 and Akt (Thr308 and Ser473) using VEGF with or without DPI. Results Intracellular ROS level were increased during endothelial progenitor cell culture and were higher in UCB compared to that of BM and increased by VEGF treatment. Proliferation, in vitro tube formation matrigel assay and migration assay on endothelial progenitor cells using SDF-1/VEGF were decreased with additions of ROS scavenger DPI when compared with that of control group. In western blot data, NOX2-based NADPH oxidase(gp91phox) was increased by VEGF and decreased by addition of DPI. VEGF induced pERK2 expression was also decreased by DPI and that finding was correlated on down-regulation of endothelial cell proliferation by DPI. Activation of Ser473 Akt was found in control group and decreased by VEGF and rebounded by VEGF and DPI. But Thr308 Akt was not activated in our experiments. Conclusions These results suggested that NOX2-based NADPH oxidase(gp91phox)-induced ROS might play important roles on EPCs migration and proliferation by VEGF. Namely, manipulating the level of ROS biochemically may alter the pathogenesis in cardiovascular and in ischemic limb diseases. In results, these data may be useful to develop new therapeutic strategies. Disclosures No relevant conflicts of interest to declare.

Download Full-text

Dynamic compression promotes proliferation and neovascular networks of endothelial progenitor cells in demineralized bone matrix scaffold seed

Journal of Applied Physiology ◽

10.1152/japplphysiol.00378.2011 ◽

2012 ◽

Vol 113 (4) ◽

pp. 619-626 ◽

Cited By ~ 9

Author(s):

Zhan Kong ◽

Jianjun Li ◽

Qun Zhao ◽

Zhendong Zhou ◽

Xiangnan Yuan ◽

...

Keyword(s):

Fracture Healing ◽

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Demineralized Bone Matrix ◽

Dynamic Compression ◽

Bone Matrix ◽

Tube Formation ◽

Endothelial Progenitor ◽

Demineralized Bone

Neovascularization is required for bone formation and successful fracture healing. In the process of neovascularization, endothelial progenitor cells (EPCs) play an important role and finish vascular repair through reendothelialization to promote successful fracture healing. In this study, we found that dynamic compression can promote the proliferation and capillary-like tube formation of EPCs in the demineralized bone matrix (DBM) scaffold seed. EPCs isolated from the bone marrow of rats have been cultured in DBM scaffolds before dynamic compression and then seeded in the DBM scaffolds under dynamic conditions. The cells/scaffold constructs were subjected to cyclic compression with 5% strain and at 1 Hz for 4 h/day for 7 consecutive days. By using MTT and real-time PCR, we found that dynamic compression can significantly induce the proliferation of EPCs in three-dimensional culture with an even distribution of cells onto DBM scaffolds. Both in vitro and in vivo, the tube formation assays in the scaffolds showed that the loaded EPCs formed significant tube-like structures. These findings suggest that dynamic compression promoted the vasculogenic activities of EPCs seeded in the scaffolds, which would benefit large bone defect tissue engineering.

Download Full-text

Abstract 1743: Stem/Progenitor Markers Sca-1 versus C-kit and CD31 Determine Angiogenic Potential of Mouse Bone Marrow-derived Endothelial Progenitor Cells

Circulation ◽

10.1161/circ.118.suppl_18.s_381 ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Toshikazu D Tanaka ◽

Masaaki Ii ◽

Haruki Sekiguchi ◽

Kentaro Jujo ◽

Sol Misener ◽

...

Keyword(s):

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Mononuclear Cells ◽

Tube Formation ◽

Mouse Bone Marrow ◽

Endothelial Progenitor ◽

Angiogenic Potential ◽

Ischemic Tissue

Background: Endothelial progenitor cells (EPCs) have been shown to have angiogenic potential contributing to neovascularization. However, the definition of EPC, including surface marker expression of EPCs promoting vasculo-/angiogenesis in ischemic tissue, remains uncertain. We hypothesized that stem/progenitor (c-kit vs. sca-1) and endothelial cell (EC) markers (CD31) may identify cells with enhanced EPC potential. Methods and Results: Mononuclear cells (MNCs) were isolated from mouse bones, and Lin+ cells were depleted by magnetic cell sorting. Lin- cells were further sorted with the following markers (% of total MNCs) by FACS: c-kit+ (1.87%), sca-1+ (0.6%), c-kit+ /CD31+ (1.1%) and sca-1+ /CD31+ (0.28%). Non-sorted MNCs were used as a control. To examine EC phenotype in culture, cells were labeled with DiI and co-cultured with mature ECs (human microvascular endothelial cells: HMVECs). The percent incorporation of DiI labeled cells into HMVEC tube structures 12 hours after co-culture and BS1-lectin positivity/acLDL uptake were: sca-1+ /CD31+ cells (87 ± 2%) > c-kit+ /CD31+ (79 ± 8%) > sca-1+ (62 ± 8%) > c-kit+ (59 ± 5%) > MNC (50 ± 3% ) . Next, we examined homing capacity of these cells to ischemic myocardium using a mouse myocardial infarction (MI) model. DiI-labeled cells (5x10 4 , IV) were injected to splenectomized mice 3 days after MI, and the hearts were excised 24 hours after the cell injection for histological analysis. Interestingly, the number of recruited/retained DiI-labeled-cells in the MI hearts exactly replicated the findings of the in vitro tube formation assay (cells/HPF): sca-1+ /CD31+ (108 ± 26) > c-kit+ /CD31+ (77 ± 16) > sca-1+ (71 ± 14) > c-kit+ (67 ± 1) > MNCs (48 ± 6) , suggesting that sca-1+ /CD31+ cells might have great functional activities as endothelial precursors. Conclusions: Both stem/progenitor marker Sca-1 and EC marker CD31 expressing EPCs exhibited high potential angiogenic capacity with EC phenotypic features compared with c-kit expressing cells. Our data suggest that Sca-1+ /CD31+ cells may represent EPC-rich cell population, and Sca-1/CD31 could be useful markers to enrich for cells with EPC potential. Ongoing studies will determine the in vivo characteristics of these cells for ischemic tissue repair.

Download Full-text

miRNA-130 Promotes Migration and Angiogenesis of Endothelial Progenitor Cells Through PI3K/AKT/mTOR Pathways

Journal of Biomaterials and Tissue Engineering ◽

10.1166/jbt.2022.2658 ◽

2022 ◽

Vol 12 (1) ◽

pp. 206-214

Author(s):

Ru-Sheng Liu ◽

Bin Li ◽

Wen-Dong Li ◽

Xiao-Long Du ◽

Xiao-Qiang Li

Keyword(s):

Progenitor Cells ◽

Signaling Pathway ◽

Endothelial Progenitor Cells ◽

Tube Formation ◽

Mtor Signaling ◽

Mtor Signaling Pathway ◽

Endothelial Progenitor ◽

Vein Thrombosis ◽

Deep Vein

<sec> <title>Aim:</title> In this study, we aimed to investigate the effects and mechanisms of miRNA-130a in human endothelial progenitor cells (EPCs) involved in Deep vein thrombosis (DVT). </sec> <sec> <title>Methods:</title> EPCs were isolated and identified by cell morphology and surface marker detection. The effect of miR-130a on the migration, invasion and angiogenesis of EPCs in vitro were also detected. In addition, whether miR-130a is involved in the MMP-1 expression and Akt/PI3K/mTOR signaling pathway was also demonstrated. </sec> <sec> <title>Results:</title> Results suggested that miRNA-130a promotes migration, invasion, and tube formation of EPCs by positively regulating the expression of MMP-1 through Akt/PI3K/mTOR signaling pathway. </sec> <sec> <title>Conclusion:</title> Thus, as a potential therapeutic target, miRNA-130a may play an important role in the treatment of DVT. </sec>

Download Full-text

Shear Stress Triggers Angiogenesis of Late Endothelial Progenitor Cells via the PTEN/Akt/GTPCH/BH4 Pathway

Stem Cells International ◽

10.1155/2020/5939530 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13

Author(s):

Shao-Hong Wu ◽

Feng Zhang ◽

Shun Yao ◽

Lu Tang ◽

Hai-Tao Zeng ◽

...

Keyword(s):

Shear Stress ◽

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Limb Ischemia ◽

Tube Formation ◽

Laminar Shear Stress ◽

Endothelial Progenitor ◽

Tensin Homolog

Background. Shear stress is an effective modulator of endothelial progenitor cells (EPCs) and has been suggested to play an important role in angiogenesis. The phosphatase and tensin homolog (PTEN)/Akt and guanosine triphosphate cyclohydrolase (GTPCH)/tetrahydrobiopterin (BH4) pathways regulate the function of early EPCs. However, the role of these pathways in the shear stress-induced angiogenesis of late EPCs remains poorly understood. Therefore, we aim to investigate whether shear stress could upregulate the angiogenesis capacity of late EPCs and to further explore the possible underlying mechanisms. Methods. Late EPCs were subjected to laminar shear stress (LSS), and their in vitro migration, proliferation, and tube formation capacity were determined. In addition, the in vivo angiogenesis capacity was explored, along with the expression of molecules involved in the PTEN/Akt and GTPCH/BH4 pathways. Results. LSS elevated the in vitro activities of late EPCs, which were accompanied by downregulated PTEN expression, accelerated Akt phosphorylation, and GTPCH/BH4 pathway activation (all P<0.05). Following Akt inhibition, LSS-induced upregulated GTPCH expression, BH4, and NO level of EPCs were suppressed. LSS significantly improved the migration, proliferation, and tube formation ability (15 dyn/cm2 LSS vs. stationary: 72.2±5.5 vs. 47.3±7.3, 0.517±0.05 vs. 0.367±0.038, and 1.664±0.315 vs. 1±0, respectively; all P<0.05) along with the in vivo angiogenesis capacity of late EPCs, contributing to the recovery of limb ischemia. These effects were also blocked by Akt inhibition or GTPCH knockdown (P<0.05, respectively). Conclusions. This study provides the first evidence that shear stress triggers angiogenesis in late EPCs via the PTEN/Akt/GTPCH/BH4 pathway, providing a potential nonpharmacologic therapeutic strategy for promoting angiogenesis in ischemia-related diseases.

Download Full-text

Activation of plasminogen into plasmin at the surface of endothelial microparticles: a mechanism that modulates angiogenic properties of endothelial progenitor cells in vitro

Blood ◽

10.1182/blood-2007-02-069997 ◽

2007 ◽

Vol 110 (7) ◽

pp. 2432-2439 ◽

Cited By ~ 115

Author(s):

Romaric Lacroix ◽

Florence Sabatier ◽

Agnès Mialhe ◽

Agnès Basire ◽

Ralph Pannell ◽

...

Keyword(s):

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Biological Activities ◽

Caproic Acid ◽

Tube Formation ◽

Endothelial Progenitor ◽

Endothelial Microparticles ◽

Type Plasminogen Activator ◽

Factor Α

The regulation of plasmin generation on cell surfaces is of critical importance in the control of vascular homeostasis. Cell-derived microparticles participate in the dissemination of biological activities. However, their capacity to promote plasmin generation has not been documented. In this study, we show that endothelial microparticles (EMPs) from tumor necrosis factor α (TNFα)–stimulated endothelial cells served as a surface for the generation of plasmin. The generation of plasmin involved expression of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) at the surface of EMPs and was further increased by their ability to bind exogenous uPA on uPAR. Plasminogen was activated at the surface of EMPs in a dose-dependent, saturable, and specific manner as indicated by the inhibition of plasmin formation by ϵ-amino-caproic acid (ϵ-ACA) and carboxypeptidase B. EMP-induced plasmin generation affects tube formation mediated by endothelial progenitor cells. However, low amounts of EMPs increased tube formation, whereas higher concentrations inhibited it. Prevention of these effects by inhibitors of either uPA or plasmin underscore the key role of EMP-induced plasmin generation. In conclusion, we demonstrated that EMPs act as vectors supporting efficient plasmin generation and dissemination, a new pathway in the regulation of endothelial proteolytic activities with potential involvement in inflammation, angiogenesis, and atherosclerosis.

Download Full-text

MicroRNA-126 Priming Enhances Functions of Endothelial Progenitor Cells under Physiological and Hypoxic Conditions and Their Therapeutic Efficacy in Cerebral Ischemic Damage

Stem Cells International ◽

10.1155/2018/2912347 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 7

Author(s):

Qunwen Pan ◽

Jieyi Zheng ◽

Donghui Du ◽

Xiaorong Liao ◽

Chunlian Ma ◽

...

Keyword(s):

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Infarct Volume ◽

Tube Formation ◽

No Production ◽

Endothelial Progenitor ◽

Beneficial Effects ◽

Hypoxic Conditions

Endothelial progenitor cells (EPCs) have shown the potential for treating ischemic stroke (IS), while microRNA-126 (miR-126) is reported to have beneficial effects on endothelial function and angiogenesis. In this study, we investigated the effects of miR-126 overexpression on EPCs and explore the efficacy of miR-126-primed EPCs (EPCmiR-126) in treating IS. The effects of miR-126 overexpression on EPC proliferation, migratory, tube formation capacity, reactive oxygen species (ROS) production, and nitric oxide (NO) generation were determined. In in vivo study, the effects of EPCmiR-126 on the cerebral blood flow (CBF), neurological deficit score (NDS), infarct volume, cerebral microvascular density (cMVD), and angiogenesis were determined. Moreover, the levels of circulating EPCs (cEPCs) and their contained miR-126 were measured. We found (1) miR-126 overexpression promoted the proliferation, migration, and tube formation abilities of EPCs; decreased ROS; and increased NO production of EPCs via activation of PI3K/Akt/eNOS pathway; (2) EPCmiR-126 was more effective than EPCs in attenuating infarct volume and NDS and enhancing cMVD, CBF, and angiogenesis; and (3) infusion of EPCmiR-126 increased the number and the level of miR-126 in cEPCs. Our data indicate that miR-126 overexpression enhanced the function of EPCs in vitro and in vivo.

Download Full-text

Erythropoietin regulates endothelial progenitor cells

Blood ◽

10.1182/blood-2003-04-1284 ◽

2004 ◽

Vol 103 (3) ◽

pp. 921-926 ◽

Cited By ~ 366

Author(s):

Ferdinand H. Bahlmann ◽

Kirsten de Groot ◽

Jens-Michael Spandau ◽

Aimee L. Landry ◽

Barbara Hertel ◽

...

Keyword(s):

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Peripheral Blood ◽

Healthy Subjects ◽

Tube Formation ◽

Dependent Manner ◽

Endothelial Progenitor ◽

Vitro Assay ◽

Dose Dependent

AbstractCirculating bone marrow–derived endothelial progenitor cells (EPCs) promote vascular reparative processes and neoangiogenesis, and their number in peripheral blood correlates with endothelial function and cardiovascular risk. We tested the hypothesis that the cytokine erythropoietin (EPO) stimulates EPCs in humans. We studied 11 patients with renal anemia and 4 healthy subjects who received standard doses of recombinant human EPO (rhEPO). Treatment with rhEPO caused a significant mobilization of CD34+/CD45+ circulating progenitor cells in peripheral blood (measured by flow cytometry), and increased the number of functionally active EPCs (measured by in vitro assay) in patients (week 2, 312% ± 31%; week 8, 308% ± 40%; both P < .01 versus baseline) as well as in healthy subjects (week 8, 194% ± 15%; P < .05 versus baseline). The effect on EPCs was already observed with an rhEPO dose of about 30 IU/kg per week. Administration of rhEPO increased the number of functionally active EPCs by differentiation in vitro in a dose-dependent manner, assessed in cell culture and by tube formation assay. Furthermore, rhEPO activates the Akt protein kinase pathway in EPCs. Erythropoietin increases the number of functionally active EPCs in humans. Administration of rhEPO or EPO analogs may open new therapeutic strategies in regenerative cardiovascular medicine.

Download Full-text

Abstract P375: Gender-based Cardio-protective Functional Dimorphism Of Bone Marrow Endothelial Progenitor Cells And Their Exosomes: Estrogen-independent Epigenetic Mechanisms

Circulation Research ◽

10.1161/res.129.suppl_1.p375 ◽

2021 ◽

Vol 129 (Suppl_1) ◽

Author(s):

Charan T Gurrala ◽

Venkata Garikipati ◽

Zhongjian Cheng ◽

Vandana Mallaredy ◽

Maria Cimini ◽

...

Keyword(s):

Bone Marrow ◽

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Capillary Density ◽

Tube Formation ◽

Ischemic Myocardium ◽

Epigenetic Mechanism ◽

Epigenetic Mechanisms ◽

Endothelial Progenitor

Introduction: Estrogen or estrogen receptor-dependent mechanisms in enhancing the cardioprotective efficacy of bone marrow endothelial progenitor cells (BM-EPC) is well-established in preclinical studies. However, the efficacy of estrogen does not reflect in the data from randomized cardiovascular clinical trials, suggesting an estrogen-independent role of female BM-EPC in eliciting enhanced cardiac protection compared to males. Hypothesis: Epigenetic mechanisms may contribute to the sex-specific dimorphism of Sca-1 + /CD31 + BM-EPC in regulating cell-homing, pro-angiogenic and anti-inflammatory functions in the ischemic myocardium leading to enhanced reparative function of female progenitor cells. Methods & Results: Transplantation of GFP-BM-mononuclear cells from male and female GFP transgenic mice into the BM of lethally irradiated recipient male C57BL/6 mice resulted in the enhanced mobilization of female Sca-1 + CD31 + /GFP + BM-EPC into circulation post-MI. A higher number of female BM-EPC homed to the ischemic myocardium and significantly improved LV functions and capillary density post-MI compared to male BM-EPC. Female BM-EPC showed increased expression of bFGF, VEGFR2, SDF-1α, and IL-10 genes, thereby efficiently promoted endothelial tube formation in vitro compared to male BM-EPC. Transplantation of female BM-EPC and their exosomes into post-MI male mice improved LV cardiac function, reduced scar size, and improved capillary density compared to male BM-EPC and exosomes. Male BM-EPC showed an increased expression of G9a/Ehmt2, an H3K9me3 methyltransferase, and Dnmt3a DNA methyltransferase compared to female BM-EPC. In contrast, Kdm6b/JMJD3, H3K27me3 demethylase was highly expressed in female BM-EPC compared to males. Treatment of BM-EPC of both sexes with 17-β-estradiol did not alter the expression of Kdm6b/JMJD3. Male BM-EPC highly expressed repressive gene marks, H3K9me3, and H3K27me3 compared to females. Compared to the male, BM-EPC from female and ovariectomized (OXV) female mice showed equally high expression of angiogenic genes ANGPT-1, MDK, PLAU, Tie-2, and VEGFR2 and lower levels of inflammatory cytokines, TNFα, IFNγ, IL-1β, and CCL3. Conditioned medium from female and OVX BM-EPC equally promoted enhanced migration and tube formation of HUVEC in vitro, compared to male BM-EPC. Conclusions: An estrogen-independent epigenetic mechanism likely governs the enhanced cardiac reparative properties of female BM-EPC.

Download Full-text

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

Clinical & Investigative Medicine ◽

10.25011/cim.v30i4.2877 ◽

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.

Download Full-text