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

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.

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

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2009.17 ◽

2009 ◽

Vol 29 (5) ◽

pp. 933-943 ◽

Cited By ~ 48

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.

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

Blood ◽

10.1182/blood.v112.11.5404.5404 ◽

2008 ◽

Vol 112 (11) ◽

pp. 5404-5404

Author(s):

Eun-Sun Yoo ◽

Jee-Young Ahn ◽

KiHwan Kwon ◽

Soo-Ah Oh ◽

Moon-Young Choi ◽

...

Keyword(s):

Cord Blood ◽

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Adhesion Molecule ◽

Mononuclear Cells ◽

Marker Genes ◽

Endothelial Progenitor ◽

Angiogenic Potential ◽

Cell Based Therapy

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

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Nrf2 deficiency diminishes angiogenic potential of endothelial progenitor cells in vitro but improves neovascularization under ischemic conditions in vivo

Vascular Pharmacology ◽

10.1016/j.vph.2011.08.033 ◽

2012 ◽

Vol 56 (5-6) ◽

pp. 317

Author(s):

Urszula Florczyk ◽

Agnieszka Jazwa ◽

Monika Maleszewska ◽

Szymon Czauderna ◽

Anna Grochot-Przeczek ◽

...

Keyword(s):

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Endothelial Progenitor ◽

Angiogenic Potential

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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.

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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.

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Effects of adipose-derived stromal cells and endothelial progenitor cells on adipose transplant survival and angiogenesis

PLoS ONE ◽

10.1371/journal.pone.0261498 ◽

2022 ◽

Vol 17 (1) ◽

pp. e0261498

Author(s):

Fengshan Gan ◽

Liu Liu ◽

Qingzhu Zhou ◽

Wenli Huang ◽

Xinwei Huang ◽

...

Keyword(s):

Adipose Tissue ◽

Blood Vessels ◽

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Tube Formation ◽

Migration And Invasion ◽

Endothelial Progenitor ◽

Angiogenic Potential ◽

Adipose Derived Stromal Cells

Background A paracrine mechanism is thought to mediate the proangiogenic capacity of adipose-derived stromal/stem cells (ASCs). However, the precise mechanism by which ASCs promote the formation of blood vessels by endothelial progenitor cells (EPCs) is unclear. Methods The EPCs-ASCs cocultures prepared in different ratios were subjected to tube formations assay to verify whether ASCs could directly participate in the tube genesis. The supernatant from cultured ASCs was used to stimulate EPCs to evaluate the effects on the angiogenic property of EPCs, as well as capacity for migration and invasion. A coculture model with transwell chamber were used to explore the regulation of angiogenesis markers expression in EPCs by ASCs. We then mixed ASCs with EPCs and transplanted them with adipose tissue into nude mice to evaluate the effects on angiogenesis in adipose tissue grafts. Results In the EPCs-ASCs cocultures, the tube formation was significantly decreased as the relative abundance of ASCs increased, while the ASCs was found to migrate and integrated into the agglomerates formed by EPCs. The supernatant from ASCs cultures promoted the migration and invasion of EPCs and the ability to form capillary-like structures. The expression of multiple angiogenesis markers in EPCs were significantly increased when cocultured with ASCs. In vivo, ASCs combined with EPC promoted vascularization in the fat transplant. Immunofluorescence straining of Edu and CD31 indicated that the Edu labeled EPC did not directly participate in the vascularization inside the fat tissue. Conclusions ADSC can participate in the tube formation of EPC although it cannot form canonical capillary structures. Meanwhile, Soluble factors secreted by ASCs promotes the angiogenic potential of EPCs. ASCs paracrine signaling appears to promote angiogenesis by increasing the migration and invasion of EPCs and simultaneously upregulating the expression of angiogenesis markers in EPCs. The results of in vivo experiments showed that ASCs combined with EPCs significantly promote the formation of blood vessels in the fat implant. Remarkably, EPCs may promote angiogenesis by paracrine regulation of endogenous endothelial cells (ECs) rather than direct participation in the formation of blood vessels.

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

Circulation ◽

10.1161/circ.118.suppl_18.s_509-a ◽

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.

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

Blood ◽

10.1182/blood.v110.11.1535.1535 ◽

2007 ◽

Vol 110 (11) ◽

pp. 1535-1535 ◽

Cited By ~ 1

Author(s):

Elisa Bonetti ◽

Vittorio Rosti ◽

Laura Villani ◽

Rita Campanelli ◽

Gaetano Bergamaschi ◽

...

Keyword(s):

Endothelial Cells ◽

Progenitor Cells ◽

Endothelial Progenitor Cells ◽

Healthy Subjects ◽

Mononuclear Cells ◽

Median Frequency ◽

Endothelial Progenitor ◽

Circulating Endothelial Progenitor Cells ◽

Mutational Status

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

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

Blood ◽

10.1182/blood.v116.21.5188.5188 ◽

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.

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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.

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