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Mervin C Yoder - One of the best experts on this subject based on the ideXlab platform.
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endothelial Colony Forming Cell function is reduced during hiv infection
The Journal of Infectious Diseases, 2019Co-Authors: Samir K Gupta, Laura S Haneline, Ziyue Liu, Emily Sims, Matthew J Repass, Mervin C YoderAbstract:BACKGROUND Human immunodeficiency virus (HIV) may be related to cardiovascular disease through monocyte activation-associated endothelial dysfunction. METHODS Blood samples from 15 HIV-negative participants (the uninfected group), 8 HIV-positive participants who were not receiving antiretroviral therapy (ART) (the infected, untreated group), and 15 HIV-positive participants who were receiving ART (the infected, treated group) underwent flow cytometry of endothelial Colony-Forming Cells (ECFCs) and monocyte proportions. IncuCyte live Cell imaging of 8 capillary proliferative capacity parameters were obtained from cord blood ECFCs treated with participant plasma. RESULTS The ECFC percentage determined by flow cytometry was not different between the study groups; however, values of the majority of capillary proliferative capacity parameters (ie, Cell area, network length, network branch points, number of networks, and average tube width uniformity) were significantly lower in infected, untreated participants as compared to values for uninfected participants or infected, treated participants (P < .00625 for all comparisons). CD14+CD16+ intermediate monocytes and soluble CD163 were significantly and negatively correlated with several plasma-treated, cord blood ECFC proliferative capacity parameters in the combined HIV-positive groups but not in the uninfected group. CONCLUSIONS Cord blood ECFC proliferative capacity was significantly impaired by plasma from infected, untreated patients, compared with plasma from uninfected participants and from infected, treated participants. Several ECFC functional parameters were adversely associated with monocyte activation in the HIV-positive groups, thereby suggesting a mechanism by which HIV-related inflammation may impair vascular reparative potential and consequently increase the risk of cardiovascular disease during HIV infection.
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Mycophenolic acid induces senescence of vascular precursor Cells
2018Co-Authors: Stefan P. Tarnawsky, Laura S Haneline, Chris W. Shelley, Kimihiko Banno, Yang Lin, Chang-hyun Gil, Emily K. Blue, Kathleen M. O’neil, Mervin C YoderAbstract:ObjectiveEndothelial dysfunction is central to the pathogenesis of many rheumatic diseases, typified by vascular inflammation and damage. Immunosuppressive drugs induce disease remission and lead to improved patient survival. However, there remains a higher incidence of cardiovascular disease in these patients even after adequate disease control. The purpose of this study was to determine the effect of mycophenolic acid (MPA), a commonly used immunosuppressive drug in rheumatology, on blood vessel or circulating endothelial Colony Forming Cell number and function.MethodsWe tested whether mycophenolic acid exerts an inhibitory effect on proliferation, clonogenic potential and vasculogenic function of endothelial Colony Forming Cell. We also studied potential mechanisms involved in the observed effects.ResultsTreatment with MPA decreased endothelial Colony Forming Cell proliferation, clonogenic potential and vasculogenic function in a dose-dependent fashion. MPA increased senescence-associated β-galactosidase expression, p21 gene expression and p53 phosphorylation, indicative of activation of Cellular senescence. Exogenous guanosine supplementation rescued diminished endothelial Colony Forming Cell proliferation and indices of senescence, consistent with the known mechanism of action of MPA.ConclusionOur findings show that clinically relevant doses of MPA have potent anti-angiogenic and pro-senescent effects on vascular precursor Cells in vitro, thus indicating that treatment with MPA can potentially affect vascular repair and regeneration. This warrants further studies in vivo to determine how MPA therapy contributes to vascular dysfunction and increased cardiovascular disease seen in patients with inflammatory rheumatic disease.
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angiopoietin like protein 2 regulates endothelial Colony Forming Cell vasculogenesis
PMC, 2014Co-Authors: Matthew R Richardson, Paul J Critser, Emilie P Robbins, Sasidhar Vemula, Catherine F Whittington, Sherry L Voytikharbin, Mervin C YoderAbstract:Angiopoietin-like 2 (ANGPTL2) has been reported to induce sprouting angiogenesis; however, its role in vasculogenesis, the de novo lumenization of endothelial Cells (EC), remains unexplored. We sought to investigate the potential role of ANGPTL2 in regulating human cord blood derived endothelial Colony Forming Cell (ECFC) vasculogenesis through siRNA mediated inhibition of ANGPTL2 gene expression. We found that ECFCs in which ANGPTL2 was diminished displayed a threefold decrease in in vitro lumenal area whereas addition of exogenous ANGPTL2 protein domains to ECFCs lead to increased lumen formation within a 3 dimensional (3D) collagen assay of vasculogenesis. ECFC migration was attenuated by 36 % via ANGPTL2 knockdown (KD) although proliferation and apoptosis were not affected. We subsequently found that c-Jun NH2-terminal kinase (JNK), but not ERK1/2, phosphorylation was decreased upon ANGPTL2 KD, and expression of membrane type 1 matrix metalloproteinase (MT1-MMP), known to be regulated by JNK and a critical regulator of EC migration and 3D lumen formation, was decreased in lumenized structures in vitro derived from ANGPTL2 silenced ECFCs. Treatment of ECFCs in 3D collagen matrices with either a JNK inhibitor or exogenous rhTIMP-3 (an inhibitor of MT1-MMP activity) resulted in a similar phenotype of decreased vascular lumen formation as observed with ANGPTL2 KD, whereas stimulation of JNK activity increased vasculogenesis. Based on gene silencing, pharmacologic, Cellular, and biochemical approaches, we conclude that ANGPTL2 positively regulates ECFC vascular lumen formation likely through its effects on migration and in part by activating JNK and increasing MT1-MMP expression.
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a hierarchy of endothelial Colony Forming Cell activity displayed by bovine corneal endothelial Cells
Investigative Ophthalmology & Visual Science, 2010Co-Authors: Lan Huang, David A. Ingram, Matthew Harkenrider, Meredith A Thompson, Pingyu Zeng, Hiromi Tanaka, David Gilley, Joseph A Bonanno, Mervin C YoderAbstract:Corneal endothelium is formed by migration and proliferation of neural crest–derived precursor Cells in the posterior aspect of the cornea where the endothelial Cells play a barrier–bump function to maintain corneal clarity. Corneal endothelial Cells (CECs) fail to proliferate in vivo in response to injury, disease, or aging and are arrested in the G1 phase of the Cell cycle.1 However, CECs possess replicative potential that can be revealed on in vitro endothelial Cell (EC) culture and/or application of a stress such as mechanical wounding or ethylene diamine tetraacetic acid (EDTA) treatment to disrupt Cell–Cell interactions within the endothelial monolayer on the ex vivo cultured cornea.2 With the use of in vitro culture approaches, recent studies have demonstrated that the proliferation of CECs varies with the age of the donor (Cells derived from younger donors divide more than those from older donors) and varies from the central (low proliferative potential) to the peripheral (high proliferative potential) cornea.2,3 These obvious differences in the temporal and spatial distribution of proliferative potential within the mammalian cornea raise an interesting question of whether all corneal endothelial Cells possess the same inherent replicative capacity or whether this property is heterogeneously distributed within Cell subsets. Vascular ECs form a monolayer that lines the interior surface of blood vessels and provides important barrier and anticoagulant properties. Vascular ECs are derived from mesodermal precursor Cells and play important roles in maintaining tissue-specific vascular homeostasis throughout human development and aging. We have discovered novel methods of examining clonal proliferative behavior of circulating and vascular ECs and have identified a hierarchy of endothelial Colony–Forming Cell (ECFC) activity, ranging from high proliferative potential ECFCs (HPP-ECFCs) to nondividing mature ECs.4,5 Human circulating ECFCs display phenotypical and functional properties that are also present in ECs derived from human blood vessels.5 Differences in the distribution of ECFCs within the microvasculature and macrovasculature ECs have been identified in some organs,6 and there are reported differences in the clonal proliferative properties of ECFCs isolated from umbilical cord blood and adult peripheral blood.4,7 Nonetheless, circulating and resident ECFCs form human blood vessels de novo when subcutaneously implanted into immunodeficient mice, and these vessels participate in carrying blood as a part of the host murine systemic circulation.7–9 Therefore, these studies suggest that ECFCs represent stem/progenitor Cells for the endothelial lineage, at least in the systemic circulation. CECs differ from vascular ECs with respect to developmental origin, anatomic localization, and physical function.1,10,11 Whereas systemic vascular endothelium slowly proliferates throughout life,12–14 CECs fail to proliferate in situ and merely expand in size to accommodate areas of CEC loss due to injury or senescence.1 This feature is well recognized in the corneas of elderly subjects in whom the CEC density may be significantly lower than that in the newborn infant cornea. Although many papers have been published over the past 30 years to explain some of the Cellular and molecular mechanisms that regulate proliferative potential in CECs,15 to our knowledge, no one has used clonal analytical techniques to examine individual CEC behavior. In this report, we examined the clonal proliferative properties of the CECs compared with the behavior displayed by ECs derived from several systemic vessels (known to possess clonal proliferative properties). We report that bovine (B)CECs display a complete hierarchy of ECFC behavior that is similar to the distribution of ECFC activity present in ECs isolated from bovine aorta, coronary artery, and pulmonary artery. HPP-ECFCs in corneal endothelium can be replated into at least secondary colonies and retain high levels of telomerase activity similar to HPP-ECFCs derived from resident endothelium in blood vessels. These novel data provide new insights into the complexity of the regulation of CEC proliferative potential, suggesting that in the adult bovine cornea, a subset of CECs with robust proliferative potential resides among numerous other CECs with limited proliferative potential.
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collagen matrix physical properties modulate endothelial Colony Forming Cell derived vessels in vivo
Microvascular Research, 2010Co-Authors: Paul J Critser, Sherry L Voytikharbin, Seth Kreger, Mervin C YoderAbstract:Developing tissue engineering approaches to generate functional vascular networks is important for improving treatments of peripheral and cardiovascular disease. Endothelial Colony Forming Cells (ECFCs) are an endothelial progenitor Cell (EPC) population defined by high proliferative potential and an ability to vascularize collagen-based matrices in vivo. Little is known regarding how physical properties of the local Cell microenvironment guide vessel formation following EPC transplantation. In vitro evidence suggests that collagen matrix stiffness may modulate EPC vessel formation. The present study determined the ability of 3D collagen matrix physical properties, varied by changing collagen concentration, to influence ECFC vasculogenesis in vivo. Human umbilical cord blood ECFCs were cultured within matrices for 18 h in vitro and then fixed for in vitro analysis or implanted subcutaneously into the flank of immunodeficient mice for 14 days. We report that increasing collagen concentration significantly decreased ECFC derived vessels per area (density), but significantly increased vessel sizes (total cross sectional area). These results demonstrate that the physical properties of collagen matrices influence ECFC vasculogenesis in vivo and that by modulating these properties, one can guide vascularization.
David M Smadja - One of the best experts on this subject based on the ideXlab platform.
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treprostinil indirectly regulates endothelial Colony Forming Cell angiogenic properties by increasing vegf a produced by mesenchymal stem Cells
European Respiratory Journal, 2015Co-Authors: David M Smadja, Lan Huang, Marilyne Levy, Elisa Rossi, D Israelbiet, Pascale Gaussem, Joyce BischoffAbstract:Background: Pulmonary vasodilators have markedly improved the outcome of patients with pulmonary hypertension (PH). Endothelial dysfunction is a key feature of PH, and we previously reported that treprostinil therapy increases number and proliferative potential of endothelial Colony Forming Cells (ECFC) isolated from PH patients. Aims: objectives were to determine how treprostinil contributes to the proangiogenic functions of ECFC. Methods: We examined effect of treprostinil on ECFC in terms of Colony numbers, proliferative and clonogenic properties in vitro, as well as in vivo vasculogenic properties. Results: Surprisingly, treprostinil inhibited viability of cultured ECFC but did not modify their clonogenic properties nor their endothelial differentiation potential from cord blood stem Cells. Treprostinil treatment significantly increased the vessel-Forming ability of ECFC combined with mesenchymal stem Cells (MSC) in Matrigel implanted in nude mice. In vitro, ECFC proliferation was stimulated by conditioned media from treprostinil-pretreated MSC, and this effect was inhibited either by VEGF-A blocking antibodies or siRNA VEGF-A in MSC. Silencing VEGF-A gene in MSC also blocked the pro-angiogenic effect of treprostinil in vivo. clinical relevance of these data was confirmed by the high level of VEGF-A detected in plasma from pediatric PH patients treated with treprostinil. Conclusion: In conclusion, increased VEGF-A produced by MSC can account for the increased vessel formation observed during treprostinil treatment. Moreover, our results suggest that VEGF-A level in patients could be a surrogate biomarker of treprostinil efficacy.
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treprostinil indirectly regulates endothelial Colony Forming Cell angiogenic properties by increasing vegf a produced by mesenchymal stem Cells
Thrombosis and Haemostasis, 2015Co-Authors: David M Smadja, Lan Huang, Marilyne Levy, Elisa Rossi, D Israelbiet, Pascale Gaussem, Adeline Blandinieres, Joyce BischoffAbstract:Pulmonary vasodilators and prostacyclin therapy in particular, have markedly improved the outcome of patients with pulmonary hypertension (PH). Endothelial dysfunction is a key feature of PH, and we previously reported that treprostinil therapy increases number and proliferative potential of endothelial Colony Forming Cells (ECFC) isolated from PH patients’ blood. In the present study, the objective was to determine how treprostinil contributes to the proangiogenic functions of ECFC. We examined the effect of treprostinil on ECFC obtained from cord blood in terms of Colony numbers, proliferative and clonogenic properties in vitro, as well as in vivo vasculogenic properties. Surprisingly, treprostinil inhibited viability of cultured ECFC but did not modify their clonogenic properties or the endothelial differentiation potential from cord blood stem Cells. Treprostinil treatment significantly increased the vessel-Forming ability of ECFC combined with mesenchymal stem Cells (MSC) in Matrigel implanted in nude mice. In vitro, ECFC proliferation was stimulated by conditioned media from treprostinil-pretreated MSC, and this effect was inhibited either by the use of VEGF-A blocking antibodies or siRNA VEGF-A in MSC. Silencing VEGF-A gene in MSC also blocked the pro-angiogenic effect of treprostinil in vivo. In conclusion, increased VEGF-A produced by MSC can account for the increased vessel formation observed during treprostinil treatment. The clinical relevance of these data was confirmed by the high level of VEGF-A detected in plasma from patients with paediatric PH who had been treated with treprostinil. Moreover, our results suggest that VEGF-A level in patients could be a surrogate biomarker of treprostinil efficacy.
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0304 treprostinil indirectly regulates endothelial Colony Forming Cell angiogenic properties by increasing vegf a produced by mesenchymal stem Cells
Archives of Cardiovascular Diseases Supplements, 2015Co-Authors: David M Smadja, Lan Huang, Marilyne Levy, Elisa Rossi, D Israelbiet, Pascale Gaussem, Joyce BischoffAbstract:Prostacyclin therapy has markedly improved the outcome of patients with pulmonary hypertension (PH). Endothelial dysfunction is a key feature of PH, so the aim of our study was to determine how treprostinil contributes to the angiogenic functions of endothelial progenitors (ECFC). Treprostinil did not modify clonogenic properties nor endothelial differentiation potential from cord blood stem Cells. Treprostinil treatment significantly increased the vessel-Forming ability of ECFC combined with mesenchymal stem Cells (MSC) in Matrigel implanted in nude mice. Silencing or blocking VEGF-A in MSC blocked the pro-angiogenic effect of treprostinil in vitro and in vivo. Clinical relevance was confirmed by the high level of VEGF-A detected in plasma from patients with pediatric pulmonary hypertension who had been treated with treprostinil. Our results suggest that VEGF-A level in patients could be a surrogate biomarker of treprostinil efficacy
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thrombospondin 1 is a plasmatic marker of peripheral arterial disease that modulates endothelial progenitor Cell angiogenic properties
Arteriosclerosis Thrombosis and Vascular Biology, 2011Co-Authors: David M Smadja, Clement Daudigier, Ivan Bieche, Solene Evrard, Laetitia Mauge, Julianavieira Dias, Julien Labreuche, Ingrid Laurendeau, Berengere Marsac, Blandine DizierAbstract:Objective— We examined whether plasma levels of angiogenic factors are altered in plasma of patients with peripheral arterial disease (PAD) and whether these factors affect endothelial progenitor Cell–induced angiogenesis. Methods and Results— Plasma was collected from 184 patients with PAD and 330 age-matched healthy controls. Vascular endothelial growth factor and placental growth factor concentrations did not differ between the groups, whereas we found a linear correlation between PAD disease and thrombospondin (TSP)-1 plasma level. TSP-1 was expressed in newly formed vessels in PAD patients having received local injections of bone marrow mononuclear Cells. To analyze the functional role of TSP-1 during neoangiogenesis, we used a Matrigel-plug assay and showed that vascularization of implanted Matrigel-plugs was increased in TSP-1 −/− mice. Moreover, injections of TSP-1 in C57Bl6/J mice after hindlimb ischemia induced a significant decrease of blood flow recovery. To investigate the effects of TSP-1 on human endothelial Colony-Forming Cell (ECFC) angiogenic potential, recombinant human TSP-1 and a small interfering RNA were used. In vitro, TSP-1 N-terminal part significantly enhanced ECFC adhesion, whereas recombinant human TSP-1 had a negative effect on ECFC angiogenic potential. This effect, mediated by CD47 binding, modulated stromal Cell–derived factor 1/CXC chemokine receptor 4 pathway. Conclusion— TSP-1 is a potential biomarker of PAD and ECFC-induced angiogenesis, suggesting that TSP-1 modulation might improve local tissue ischemia in this setting. (Clinical trial registration: NCT00377897.)
Hassan Azari - One of the best experts on this subject based on the ideXlab platform.
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depletion of neural stem Cells from the subventricular zone of adult mouse brain using cytosine b arabinofuranoside
Brain and behavior, 2015Co-Authors: Amir Ghanbari, Sharareh Sharififar, Mohammad Ghasem Golmohammadi, Tahereh Esmaeilpour, Soghra Bahmanpour, Hassan AzariAbstract:Neural stem Cells (NSCs) reside along the ventricular axis of the mammalian brain. They divide infrequently to maintain themselves and the down-stream progenitors. Due to the quiescent property of NSCs, attempts to deplete these Cells using antimitotic agents such as cytosine b-Aarabinofuranoside (Ara-C) have not been successful. We hypothesized that implementing infusion gaps in Ara-C kill paradigms would recruit the quiescent NSCs and subsequently eliminate them from their niches in the subventricular zone (SVZ).We infused the right lateral ventricle of adult mice brain with 2% Ara-C using four different paradigms--1: one week; 2: two weeks; 3, 4: two weeks with an infusion gap of 6 and 12 h on day 7. Neurosphere assay (NSA), neural Colony-Forming Cell assay (N-CFCA) and immunofluorescent staining were used to assess depletion of NSCs from the SVZ.Neurosphere formation dramatically decreased in all paradigms immediately after Ara-C infusion. Reduction in neurosphere formation was more pronounced in the 3rd and 4th paradigms. Interestingly 1 week after Ara-C infusion, neurosphere formation recovered toward control values implying the presence of NSCs in the harvested SVZ tissue. Unexpectedly, N-CFCA in the 3rd paradigm, as one of the most effective paradigms, did not result in formation of NSC-derived colonies (colonies >2 mm) even from SVZs harvested 1 week after completion of Ara-C infusion. However, formation of big colonies with serial passaging capability, again confirmed the presence of NSCs.Overall, these data suggest Ara-C kill paradigms with infusion gaps deplete NSCs in the SVZ more efficiently but the niches would repopulate even after the most vigorous kill paradigm used in this study.
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purification of immature neuronal Cells from neural stem Cell progeny
PLOS ONE, 2011Co-Authors: Loic P. Deleyrolle, Hassan Azari, Mohammad Ghasem Golmohammadi, Geoffrey W Osborne, Takahiro Yasuda, Maryam Rahman, Ebrahim EsfandiariAbstract:Large-scale proliferation and multi-lineage differentiation capabilities make neural stem Cells (NSCs) a promising renewable source of Cells for therapeutic applications. However, the practical application for neuronal Cell replacement is limited by heterogeneity of NSC progeny, relatively low yield of neurons, predominance of astrocytes, poor survival of donor Cells following transplantation and the potential for uncontrolled proliferation of precursor Cells. To address these impediments, we have developed a method for the generation of highly enriched immature neurons from murine NSC progeny. Adaptation of the standard differentiation procedure in concert with flow cytometry selection, using scattered light and positive fluorescent light selection based on Cell surface antibody binding, provided a near pure (97%) immature neuron population. Using the purified neurons, we screened a panel of growth factors and found that bone morphogenetic protein-4 (BMP-4) demonstrated a strong survival effect on the Cells in vitro, and enhanced their functional maturity. This effect was maintained following transplantation into the adult mouse striatum where we observed a 2-fold increase in the survival of the implanted Cells and a 3-fold increase in NeuN expression. Additionally, based on the neural-Colony Forming Cell assay (N-CFCA), we noted a 64 fold reduction of the bona fide NSC frequency in neuronal Cell population and that implanted donor Cells showed no signs of excessive or uncontrolled proliferation. The ability to provide defined neural Cell populations from renewable sources such as NSC may find application for Cell replacement therapies in the central nervous system.
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neural Colony Forming Cell assay an assay to discriminate bona fide neural stem Cells from neural progenitor Cells
Journal of Visualized Experiments, 2011Co-Authors: Hassan Azari, Sharon A. Louis, Sharareh Sharififar, Vinata Vedammai, Brent A ReynoldsAbstract:The neurosphere assay (NSA) is one of the most frequently used methods to isolate, expand and also calculate the frequency of neural stem Cells (NSCs). Furthermore, this serum-free culture system has also been employed to expand stem Cells and determine their frequency from a variety of tumors and normal tissues. It has been shown recently that a one-to-one relationship does not exist between neurosphere formation and NSCs. This suggests that the NSA as currently applied, overestimates the frequency of NSCs in a mixed population of neural precursor Cells isolated from both the embryonic and adult mammalian brain. This video practically demonstrates a novel collagen based semi- solid assay, the neural-Colony Forming Cell assay (N-CFCA), which has the ability to discriminate stem from progenitor Cells based on their long-term proliferative potential, and thus provides a method to enumerate NSC frequency. In the N-CFCA, colonies ≥2 mm in diameter are derived from Cells that meet all the functional criteria of a NSC, while colonies < 2mm are derived from progenitors. The N-CFCA procedure can be used for Cells prepared from different sources including primary and cultured adult or embryonic mouse CNS Cells. Here we use Cells prepared from passage one neurospheres generated from embryonic day 14 mice brain to perform N-CFCA. The cultures are replenished with proliferation medium every seven days for three weeks to allow the plated Cells to exhibit their full proliferative potential and then the frequency of neural progenitor and bona fide neural stem Cells is calculated respectively by counting the number of colonies that are < 2mm and the ones that are ≥2mm in reference to the number of Cells that were initially plated.
Joyce Bischoff - One of the best experts on this subject based on the ideXlab platform.
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treprostinil indirectly regulates endothelial Colony Forming Cell angiogenic properties by increasing vegf a produced by mesenchymal stem Cells
European Respiratory Journal, 2015Co-Authors: David M Smadja, Lan Huang, Marilyne Levy, Elisa Rossi, D Israelbiet, Pascale Gaussem, Joyce BischoffAbstract:Background: Pulmonary vasodilators have markedly improved the outcome of patients with pulmonary hypertension (PH). Endothelial dysfunction is a key feature of PH, and we previously reported that treprostinil therapy increases number and proliferative potential of endothelial Colony Forming Cells (ECFC) isolated from PH patients. Aims: objectives were to determine how treprostinil contributes to the proangiogenic functions of ECFC. Methods: We examined effect of treprostinil on ECFC in terms of Colony numbers, proliferative and clonogenic properties in vitro, as well as in vivo vasculogenic properties. Results: Surprisingly, treprostinil inhibited viability of cultured ECFC but did not modify their clonogenic properties nor their endothelial differentiation potential from cord blood stem Cells. Treprostinil treatment significantly increased the vessel-Forming ability of ECFC combined with mesenchymal stem Cells (MSC) in Matrigel implanted in nude mice. In vitro, ECFC proliferation was stimulated by conditioned media from treprostinil-pretreated MSC, and this effect was inhibited either by VEGF-A blocking antibodies or siRNA VEGF-A in MSC. Silencing VEGF-A gene in MSC also blocked the pro-angiogenic effect of treprostinil in vivo. clinical relevance of these data was confirmed by the high level of VEGF-A detected in plasma from pediatric PH patients treated with treprostinil. Conclusion: In conclusion, increased VEGF-A produced by MSC can account for the increased vessel formation observed during treprostinil treatment. Moreover, our results suggest that VEGF-A level in patients could be a surrogate biomarker of treprostinil efficacy.
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treprostinil indirectly regulates endothelial Colony Forming Cell angiogenic properties by increasing vegf a produced by mesenchymal stem Cells
Thrombosis and Haemostasis, 2015Co-Authors: David M Smadja, Lan Huang, Marilyne Levy, Elisa Rossi, D Israelbiet, Pascale Gaussem, Adeline Blandinieres, Joyce BischoffAbstract:Pulmonary vasodilators and prostacyclin therapy in particular, have markedly improved the outcome of patients with pulmonary hypertension (PH). Endothelial dysfunction is a key feature of PH, and we previously reported that treprostinil therapy increases number and proliferative potential of endothelial Colony Forming Cells (ECFC) isolated from PH patients’ blood. In the present study, the objective was to determine how treprostinil contributes to the proangiogenic functions of ECFC. We examined the effect of treprostinil on ECFC obtained from cord blood in terms of Colony numbers, proliferative and clonogenic properties in vitro, as well as in vivo vasculogenic properties. Surprisingly, treprostinil inhibited viability of cultured ECFC but did not modify their clonogenic properties or the endothelial differentiation potential from cord blood stem Cells. Treprostinil treatment significantly increased the vessel-Forming ability of ECFC combined with mesenchymal stem Cells (MSC) in Matrigel implanted in nude mice. In vitro, ECFC proliferation was stimulated by conditioned media from treprostinil-pretreated MSC, and this effect was inhibited either by the use of VEGF-A blocking antibodies or siRNA VEGF-A in MSC. Silencing VEGF-A gene in MSC also blocked the pro-angiogenic effect of treprostinil in vivo. In conclusion, increased VEGF-A produced by MSC can account for the increased vessel formation observed during treprostinil treatment. The clinical relevance of these data was confirmed by the high level of VEGF-A detected in plasma from patients with paediatric PH who had been treated with treprostinil. Moreover, our results suggest that VEGF-A level in patients could be a surrogate biomarker of treprostinil efficacy.
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0304 treprostinil indirectly regulates endothelial Colony Forming Cell angiogenic properties by increasing vegf a produced by mesenchymal stem Cells
Archives of Cardiovascular Diseases Supplements, 2015Co-Authors: David M Smadja, Lan Huang, Marilyne Levy, Elisa Rossi, D Israelbiet, Pascale Gaussem, Joyce BischoffAbstract:Prostacyclin therapy has markedly improved the outcome of patients with pulmonary hypertension (PH). Endothelial dysfunction is a key feature of PH, so the aim of our study was to determine how treprostinil contributes to the angiogenic functions of endothelial progenitors (ECFC). Treprostinil did not modify clonogenic properties nor endothelial differentiation potential from cord blood stem Cells. Treprostinil treatment significantly increased the vessel-Forming ability of ECFC combined with mesenchymal stem Cells (MSC) in Matrigel implanted in nude mice. Silencing or blocking VEGF-A in MSC blocked the pro-angiogenic effect of treprostinil in vitro and in vivo. Clinical relevance was confirmed by the high level of VEGF-A detected in plasma from patients with pediatric pulmonary hypertension who had been treated with treprostinil. Our results suggest that VEGF-A level in patients could be a surrogate biomarker of treprostinil efficacy
Kevin D Burns - One of the best experts on this subject based on the ideXlab platform.
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Receptor-Ligand Interaction Mediates Targeting of Endothelial Colony Forming Cell-derived Exosomes to the Kidney after Ischemic Injury
Scientific Reports, 2018Co-Authors: J L Viñas, Matthew Spence, William Knoll, Dylan Burger, Joseph Zimpelmann, David S. Allan, Alex Gutsol, Kevin D BurnsAbstract:Endothelial Colony Forming Cell (ECFC)-derived exosomes protect mice against ischemic kidney injury, via transfer of microRNA-(miR)-486-5p. Mechanisms mediating exosome recruitment to tissues are unclear. We hypothesized that ECFC exosomes target ischemic kidneys, involving interaction between exosomal CXC chemokine receptor type 4 (CXCR4) and stromal Cell-derived factor (SDF)-1α. Ischemia-reperfusion was induced in mice by bilateral renal vascular clamp, with intravenous infusion of exosomes at reperfusion. Optical imaging determined exosome biodistribution, and miR-486-5p was measured by real-time PCR. Human umbilical vein endothelial Cells (HUVECs) were cultured to study the CXCR4/SDF-1α interaction. Targeting of administered exosomes to ischemic kidneys was detected 30 min and 4 hrs after reperfusion. Exosomes increased miR-486-5p levels only in kidneys, within proximal tubules, glomeruli, and endothelial Cells. Uptake of fluorescently-labeled exosomes into HUVECs, and exosomal transfer of miR-486-5p were enhanced by hypoxia, effects blocked by neutralizing antibody to SDF-1α or by the CXCR4 inhibitor plerixafor. Infusion of ECFC exosomes prevented ischemic kidney injury in vivo , an effect that was not observed when exosomes were pre-incubated with plerixafor. These data indicate that ECFC exosomes selectively target the kidneys after ischemic injury, with rapid Cellular transfer of miR486-5p. Targeting of exosomes may involve interaction of CXCR4 with endothelial Cell SDF-1α.
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transfer of microrna 486 5p from human endothelial Colony Forming Cell derived exosomes reduces ischemic kidney injury
Kidney International, 2016Co-Authors: J L Viñas, William Knoll, Dylan Burger, Joseph Zimpelmann, David S. Allan, Alex Gutsol, Randa Haneef, Pearl A Campbell, Anthony Carter, Kevin D BurnsAbstract:Administration of human cord blood endothelial Colony-Forming Cells (ECFCs) or their exosomes protects mice against kidney ischemia/reperfusion injury. Here we studied the microRNA (miRNA) content of ECFC exosomes and the role of miRNA transfer in kidney and endothelial Cell protection. ECFC exosomes were enriched in miR-486-5p, which targets the phosphatase and tensin homolog (PTEN) and the Akt pathway. In cultured endothelial Cells exposed to hypoxia, incubation with ECFC exosomes increased miR-486-5p, decreased PTEN, and stimulated Akt phosphorylation. Exposure of hypoxic endothelial Cells to conditioned medium from ECFCs pretreated with anti–miR-486-5p blocked increases in miR-486-5p and phosphorylated Akt, restored expression of PTEN, and enhanced apoptosis. Coculture of endothelial Cells with ECFCs enhanced endothelial miR-486-5p levels. Targeting of PTEN by miR-486-5p was observed in endothelial Cells, and PTEN knockdown blocked apoptosis. In mice with ischemic kidney injury, infusion of ECFC exosomes induced potent functional and histologic protection, associated with increased kidney miR-486-5p levels, decreased PTEN, and activation of Akt. Infusion of exosomes from ECFCs transfected with anti–miR-486-5p had no protective effect. Thus, delivery of ECFC exosomes reduces ischemic kidney injury via transfer of miR-486-5p targeting PTEN. Exosomes enriched in miR-486-5p could represent a therapeutic tool in acute kidney injury.