The therapeutic effects of endothelial progenitor cells (EPCs) on ischemic stroke have been extensively studied in recent years. However, the differences in early EPCs and endothelial outgrowth cells (EOCs) are still unclear. Clarifications of their respective properties and specific functioning characteristics contribute to better applications of EPCs in ischemic diseases. In this review, we discuss cellular origin, isolation, culture, surface markers of early EPCs and EOCs and relevant applications in neurological diseases. We conclude that EOCs possess all haracteristics of true endothelial progenitors and have potent advantages in EPC-based therapies for ischemic diseases. A number of preclinical and clinical applications of EPCs in neurological diseases are under study. More studies are needed to determine the specific characteristics of EPCs and the relevant mechanisms of EPCs for neurological diseases.
Classification* ; Endothelial Progenitor Cells ; Stroke ; Therapeutic Uses

JAK2V617F is a novel oncogene involved in myeloproliferative neoplasms (MPN) and closely related to its vascular complications. Recent researches found the vascular endothelial injury in patients with MPN. It is increasingly being recognized that endothelial cells and endothelial progenitor cells (EPC) play an important role in MPN. Here, the pathogenesis of the EPC JAK2V617F mutation and peripheral blood EPC counts in patients with MPN or with vascular complications are reviewed.
Endothelial Cells ; Endothelial Progenitor Cells ; Humans ; Janus Kinase 2 ; Mutation ; Myeloproliferative Disorders

OBJECTIVETo investigate the expression patterns of CD133+ endothelial progenitor cell (EPC) on Wister rats during experimental tooth movement.

METHODS40 Wistar rats' teeth movement models were established and divided into experiment group and control group. After loading 1, 3, 5, 7, 14 days killed them respectively. The histological sections were stained with hematoxylin-eosin and rabbit anti-rat CD133 polyclonal antibody to express CD133 immunoreactivity.

RESULTSExpression of CD133 in the new vessels did not appear in control group. In the early experiment, the expression of CD133 was discovered in the new vascular endothelial cells of periodontium in experiment group. Expression of CD133 got the maximum after loading 1 day in experiment group, then decreased gradually, but it was not significantly higher than control group (P > 0.05).

CONCLUSIONCD133+ EPC participated vascularized reaction in periodontal tissue of rat during the experimental tooth movement, direct participation was few and indirect effects possibly existed.

Animals ; Endothelial Cells ; Endothelial Progenitor Cells ; Periodontal Ligament ; Rats ; Rats, Wistar ; Tooth Movement Techniques

Tumor undergo uncontrolled, excessive proliferation leads to hypoxic microenvironment. To fulfill their demand for nutrient, and oxygen, tumor angiogenesis is required. Endothelial progenitor cells (EPCs) have been known to the main source of angiogenesis because of their potential to differentiation into endothelial cells. Therefore, understanding the mechanism of EPC-mediated angiogenesis in hypoxia is critical for development of cancer therapy. Recently, mitochondrial dynamics has emerged as a critical mechanism for cellular function and differentiation under hypoxic conditions. However, the role of mitochondrial dynamics in hypoxia-induced angiogenesis remains to be elucidated. In this study, we demonstrated that hypoxia-induced mitochondrial fission accelerates EPCs bioactivities. We first investigated the effect of hypoxia on EPC-mediated angiogenesis. Cell migration, invasion, and tube formation was significantly increased under hypoxic conditions; expression of EPC surface markers was unchanged. And mitochondrial fission was induced by hypoxia time-dependent manner. We found that hypoxia-induced mitochondrial fission was triggered by dynamin-related protein Drp1, specifically, phosphorylated DRP1 at Ser637, a suppression marker for mitochondrial fission, was impaired in hypoxia time-dependent manner. To confirm the role of DRP1 in EPC-mediated angiogenesis, we analyzed cell bioactivities using Mdivi-1, a selective DRP1 inhibitor, and DRP1 siRNA. DRP1 silencing or Mdivi-1 treatment dramatically reduced cell migration, invasion, and tube formation in EPCs, but the expression of EPC surface markers was unchanged. In conclusion, we uncovered a novel role of mitochondrial fission in hypoxia-induced angiogenesis. Therefore, we suggest that specific modulation of DRP1-mediated mitochondrial dynamics may be a potential therapeutic strategy in EPC-mediated tumor angiogenesis.
Anoxia ; Cell Movement ; Endothelial Cells ; Endothelial Progenitor Cells* ; Mitochondrial Dynamics* ; Oxygen ; RNA, Small Interfering

OBJECTIVE: To investigate the effects of endothelial progenitor cells (EPCs) under shear stress on the biological function such as proliferation, adhesion, migration, apoptosis and expression of α-smooth muscle actin (α-SMA), collagen-I and collagen-Ⅲ of hepatic stellate cells (HSCs). METHODS: HSCs and EPCs were inoculated into the upper and lower layers of the co-culture chamber respectively and co-incubated for 24 hours. Then, 12 dyne/cm shear stress was applied to EPCs cells for another 24 hours. After that, proliferation, adhesion, migration and apoptosis of HSCs were detected by cell counting kit-8 (CCK-8) kit, cell adherent assay, Boyden cell migration assay and flow cytometry respectively. Fluorescence quantitative PCR and Western blot were used to detect the mRNA and protein expression of alpha -SMA, collagen I and collagen-Ⅲ in HSCs. RESULTS: Under shear stress, EPCs ecological niche could obviously inhibit the proliferation, adhesion and migration of HSCs, promote the apoptosis of HSCs, and down-regulate the mRNA and protein expression of collagen-I, collagen-Ⅲ in HSC cells. CONCLUSIONS Under shear stress, EPCs ecological niche could inhibit the fibrosis development of HSCs to a certain extent.
Actins ; Apoptosis ; Cell Proliferation ; Cells, Cultured ; Collagen Type I ; Endothelial Progenitor Cells ; Hepatic Stellate Cells

OBJECTIVE: To establish a novel method to isolate endothelial progenitor cells（EPC） from cryopreserved umbilical cord blood (cryoUCB), to investigate the biological characteristics of EPC and to improve the rate of EPC obtained from cryoUCB. METHODS: Twelve cryoUCB samples during 2000 to 2001 years were collected from allogeneic cord blood bank, cryoUCB was thawed rapidly in a water bath at 37 ℃, total nucleated cells (TNCs) were washed by phosphate-buffered saline (PBS). TNCs were seeded onto fibronectin-coated dishes to isolate EPC. Flow cytometry and immunofluorescence were used to identify EPC. The function of EPC was identified in vitro, such as the incorporation of Dil-Ac-LDL and FITC-UEA-I, the formation of capillary-like structure in matrigel, and the release of VEGF by ELISA. RESULTS: One to five cluster of cobble stone-like cells appeared at 2-3 weeks after seeding. Flow cytometric analysis showed that positive rates of CD31, CD34, CD144, and VEGFR (CD309) were（92.91±5.20）%, （30.0±23.27）%, （88.55±3.83）% and （67.21±12.12）% in passage 1 to passage 3 of EPC. EPC could uptake Dil-Ac-LDL and FITC-UEA-I, form capillary-like network on Matriget and release VEGF. CONCLUSION EPC had been successfully isolated from cryopreserved umbilical cord blood by this method with high stability and reproducibility. EPC can be obtained in 85% frozen umbilical cord blood. This method may lay a foundation to supply abundant EPC for clinical application.
Cell Differentiation ; Cells, Cultured ; Endothelial Progenitor Cells ; Fetal Blood ; Reproducibility of Results ; Stem Cells

OBJECTIVETo investigate the optimal dosage and timing for 5-bromodeoxyuridine (BrdU) labeling of endothelial progenitor cells (EPCs) from rat circulating blood.

METHODSThe animal model for rat tooth movement was established. EPCs were obtained by density gradient centrifugation. The expressions of specific antigens on cell surface were analysed by immunocytochemistry and fluorescenceochemistry. EPCs were incubated with BrdU at different concentrations (5, 10, 15 micromol/L) for different incubating time (12, 24, 48, 72, 96 h) to identify the optimal BrdU concentration and incubating time for cell labeling. Immunohistochemistry was performed to calculate the labeling index (LI).

RESULTSThe culture cell positively expressed CD34, CD133 and could be shown to endocytose DiI-ac-LDL, FITC-UEA-1. Incubation of the EPCs with BrdU at 10 micromol/L and for an optimal length of 72 h appeared to achieve the highest LI (66.8+/-2.9)%, which was significantly higher than group of 5 micromol/L (P<0.05), while there was no significant difference between the group of 15 micromol/L and 10 micromol/L (P>0.05).

CONCLUSIONEPCs can be isolated from tooth movement rat circulating blood and cultured. Incubation of the EPCs with BrdU at 10 micromol/L and for an optimal length of 72 h appeared to achieve the optimal LI. This provides a foundation for us to investigate the mechanism of chemiotaxis and differentiation for EPCs.

Animals ; Bromodeoxyuridine ; Cell Culture Techniques ; Cell Differentiation ; Cells, Cultured ; Endothelial Cells ; Endothelial Progenitor Cells ; Rats ; Stem Cells ; Tooth Movement Techniques

Store-operated calcium entry (SOCE), a major mode of extracellular calcium entry, plays roles in a variety of cell activities. Accumulating evidence indicates that the intracellular calcium ion concentration and calcium signaling are critical for the responses induced by oxidative stress. The present study was designed to investigate the potential effect of SOCE inhibition on H₂O₂-induced apoptosis in endothelial progenitor cells (EPCs), which are the predominant cells involved in endothelial repair. The results showed that H₂O₂-induced EPC apoptosis was reversed by SOCE inhibition induced either using the SOCE antagonist ML-9 or via silencing of stromal interaction molecule 1 (STIM1), a component of SOCE. Furthermore, SOCE inhibition repressed the increases in intracellular reactive oxygen species (ROS) levels and endoplasmic reticulum (ER) stress and ameliorated the mitochondrial dysfunction caused by H₂O₂. Our findings provide evidence that SOCE inhibition exerts a protective effect on EPCs in response to oxidative stress induced by H₂O₂ and may serve as a potential therapeutic strategy against vascular endothelial injury.
Apoptosis* ; Calcium Signaling ; Calcium* ; Endoplasmic Reticulum ; Endothelial Progenitor Cells* ; Oxidative Stress ; Reactive Oxygen Species

Endothelial dysfunction in atherosclerosis is associated with increasing oxidative stress that could be reversed by antioxidant. Therefore epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC) and catechin (C) of tea flavonoids were investigated for their roles in regenerating endothelial cell. Peripheral blood mononuclear cells (PB-MNCs) were isolated, plated and cultured in medium with/without treatment of EGCG, ECG, EGC and C. Results showed that among all EGCG, ECG, EGC and C concentrations tested, 12.5 µmol/L was not cytotoxic for peripheral blood-derived endothelial progenitor cells (PB-EPCs). Treatment of EGCG, ECG, EGC or C increased the percentages of CD34, CD133, VEGFR-2 expressions and suppressed hydrogen peroxide-induced percentages of reactive oxygen species (ROS) level in PB-EPCs. Taken together, our current results showed that EGCG, ECG, EGC or C of tea flavonoids could induce differentiation of PB-MNCs into PB-EPCs as well as protect PB-EPCs from oxidative damage by suppresing the intracellular ROS levels.
Apoptosis ; Atherosclerosis ; Catechin ; Electrocardiography ; Endothelial Cells ; Endothelial Progenitor Cells* ; Flavonoids* ; Hydrogen ; Oxidative Stress ; Reactive Oxygen Species* ; Tea* ; Vascular Endothelial Growth Factor Receptor-2

Dysfunction or loss of blood vessel causes several ischemic diseases. Although endothelial progenitor cells (EPCs) are a promising source for cell-based therapy, ischemia-induced pathophysiological condition limits the recovery rate by causing drastic cell death. To overcome this issue, we attempted to develop a cell-targeted peptide delivery and priming system to enhance EPCbased neovascularization using an engineered M13 bacteriophage harboring nanofibrous tubes displaying ∼ 2700 multiple functional motifs. The M13 nanofiber was modified by displaying RGD, which is an integrin-docking peptide, on the minor coat protein, and bymutilayering SDKPmotifs,which are the key active sites for thymosin b4, on themajor coat protein. The engineered M13 nanofiber dramatically enhanced ischemic neovascularization by activating intracellular and extracellular processes such as proliferation, migration, and tube formation in the EPCs. Furthermore, transplantation of the primed EPCs with the M13 nanofiber harboring RGD and SDKP facilitated functional recovery and neovascularization in a murine hindlimb ischemia model. Overall, this study demonstrates the effectiveness of theM13 nanofiber-based novel peptide deliveryandprimingstrategy inpromotingEPC bioactivity and neovessel regeneration. To our knowledge, this is first report onM13 nanofibers harboring dual functional motifs, the use of which might be a novel strategy for stem and progenitor cell therapy against cardiovascular ischemic diseases.
Animals ; Bacteriophages ; Blood Vessels ; Catalytic Domain ; Cell Death ; Endothelial Progenitor Cells* ; Hindlimb ; Ischemia ; Nanofibers* ; Regeneration ; Stem Cells ; Thymosin