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

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.

scholarly journals Role of β2-integrins for homing and neovascularization capacity of endothelial progenitor cells

2004 ◽  
Vol 201 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Emmanouil Chavakis ◽  
Alexandra Aicher ◽  
Christopher Heeschen ◽  
Ken-ichiro Sasaki ◽  
Ralf Kaiser ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Ex Vivo ◽  
Limb Ischemia ◽  
Endothelial Progenitor ◽  
Cell Monolayers ◽  
Β2 Integrins

The mechanisms of homing of endothelial progenitor cells (EPCs) to sites of ischemia are unclear. Here, we demonstrate that ex vivo–expanded EPCs as well as murine hematopoietic Sca-1+/Lin− progenitor cells express β2-integrins, which mediate the adhesion of EPCs to endothelial cell monolayers and their chemokine-induced transendothelial migration in vitro. In a murine model of hind limb ischemia, Sca-1+/Lin− hematopoietic progenitor cells from β2-integrin–deficient mice are less capable of homing to sites of ischemia and of improving neovascularization. Preactivation of the β2-integrins expressed on EPCs by activating antibodies augments the EPC-induced neovascularization in vivo. These results provide evidence for a novel function of β2-integrins in postnatal vasculogenesis.

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

Circulation ◽  
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.

Importance of β2AR elevation for re-endothelialization capacity mediated by late endothelial progenitor cells in hypertensive patients

2020 ◽  
Author(s):  
Qingsong Hu ◽  
Yiqun Guo ◽  
Tao Zhang ◽  
Jianyi Feng ◽  
Jinlong Wang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
P38 Mapk ◽  
Caspase 3 ◽  
Pharmacological Intervention ◽  
Endothelial Progenitor ◽  
Hypertensive Patients

Dysfunction of late endothelial progenitor cells (EPCs) has been suggested to be associated with hypertension. β2 adrenergic receptor (β2AR) is a novel and key target for EPCs homing. Here, we proposed that attenuated β2AR signaling contributes to EPCs dysfunction, whereas enhanced β2AR signaling restores EPCs' functions in hypertension. EPCs derived from hypertensive patients exhibited reduced cell number, impaired in vitro migratory and adhesion abilities, and impaired re-endothelialization after transplantation in nude mice with carotid artery injury. β2AR expression of EPCs from hypertensive patients was markedly downregulated, whereas the phosphorylation of the p38 mitogen-activated protein kinase (p38-MAPK) was elevated. The cleaved caspase-3 levels were elevated in EPCs. The overexpression of β2AR in EPCs from hypertensive patients inhibited p38-MAPK signaling while enhanced in vitro EPC proliferation, migration and adhesion, and in vivo re-endothelialization. The β2AR-mediated effects were attenuated by treating the EPCs with a neutralizing monoclonal antibody against β2AR, which could be partially antagonized by the p38-MAPK inhibitor SB203580. Moreover, shear stress stimulation, a classic non-pharmacological intervention, increased the phosphorylation levels of β2AR and enhanced the in vitro and in vivo functions of EPCs from hypertensive patients. Collectively, the current investigation demonstrated that impaired β2AR/p38MAPK/caspase-3 signaling at least partially reduced the re-endothelialization capacity of EPCs from hypertensive patients. Restoration of β2AR expression and shear stress treatment could improve their endothelial repair capacity by regulating the p38MAPK/caspase-3 signaling pathway. The clinical significance of β2AR in endothelium repair still requires further investigation.

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

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
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.

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.

β2AR-dependent signaling contributes to in-vivo reendothelialization capacity of endothelial progenitor cells by shear stress

2020 ◽  
Vol 38 (1) ◽  
pp. 82-94 ◽  
Author(s):  
Qingsong Hu ◽  
Tao Zhang ◽  
Yan Li ◽  
Jianyi Feng ◽  
Ruqiong Nie ◽  
...  
Keyword(s):  
Shear Stress ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Endothelial Progenitor

Shear stress regulates inflammatory and thrombogenic gene transcripts in cultured human endothelial progenitor cells

2010 ◽  
Vol 104 (09) ◽  
pp. 582-591 ◽  
Author(s):  
Trine Lund ◽  
Stig Hermansen ◽  
Thomas Andreasen ◽  
Jan Olsen ◽  
Bjarne Østerud ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Mrna Expression ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Mrna Levels ◽  
Endothelial Progenitor ◽  
Gene Transcripts ◽  
Nos Inhibitor

SummaryShear stress has an established effect on mature endothelial cells, but less is known about how shear stress regulates endothelial progenitor cells (EPCs). In vitro expanded EPCs isolated from adult human blood represent a novel tool in regenerative vessel therapy. However, in vitro culturing may generate cells with unfavourable properties. The aim of the present study was therefore to assess whether shear stress may influence the inflammatory and thrombotic phenotype of in vitro expanded EPCs. In late outgrowth EPCs, 6 hours of shear stress (6.0 dynes/ cm2) significantly reduced the mRNA levels of IL-8, COX2, and tissue factor (TF) compared to static controls. This was associated with a reduced TF activity. In contrast, mRNA expression of NOS3 was significantly increased following 6 and 24 hours of shear stress. In accordance with this, NOS3 protein expression was increased following 24 hours of shear stress. Overall stimulation with the proinflammatory mediator, TNFα, for the final 2 hours increased the mRNA expression of IL-6, IL-8, MCP-1, ICAM1, and TF. However exposure to 6 hours of shear stress significantly suppressed the inductory potential of TNFα to increase the mRNA levels of IL-6, IL-8, COX2, and TF. Additionally, TNFα increased TF activity approximately 10 times, an effect that was also significantly reduced by exposure to 6 and 24 hours of shear stress. The effect of shear on the gene levels of TF and NOS3 were not blocked by the NOS inhibitor L-NAME. These observations suggest that EPCs are capable of functionally responding to shear stress.

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

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 5188-5188
Author(s):  
Eun-Sun Yoo ◽  
Yeung-Chul Mun ◽  
Eun Mi Nam ◽  
Kyoung Eun Lee ◽  
Jung Won Huh ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Western Blot ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Tube Formation ◽  
Sirna Transfection ◽  
Endothelial Progenitor ◽  
Intracellular Ros ◽  
Perk Expression

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.

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

2012 ◽  
Vol 113 (4) ◽  
pp. 619-626 ◽  
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.

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