This study aims to investigate the molecular mechanism of tanshinone Ⅱ_(A )(TaⅡ_A) combined with endothelial progenitor cells-derived exosomes(EPCs-exos) in protecting the aortic vascular endothelial cells(AVECs) from oxidative damage via the phosphatidylinositol 3 kinase(PI3K)/protein kinase B(Akt) pathway. The AVECs induced by 1-palmitoyl-2-(5'-oxovaleroyl)-sn-glycero-3-phosphocholine(POVPC) were randomly divided into model, TaⅡ_A, EPCs-exos, and TaⅡ_A+EPCs-exos groups, and the normal cells were taken as the control group. The cell counting kit-8(CCK-8) was used to examine the cell proliferation. The lactate dehydrogenase(LDH) cytotoxicity assay kit, Matrigel assay, DCFH-DA fluorescent probe, and laser confocal microscopy were employed to examine the LDH release, tube-forming ability, cellular reactive oxygen species(ROS) level, and endothelial cell skeleton morphology, respectively. The enzyme-linked immunosorbent assay was employed to measure the expression of interleukin(IL)-1β, IL-6, and tumor necrosis factor(TNF)-α. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to determine the mRNA and protein levels, respectively, of PI3K and Akt. Compared with the control group, the model group showed decreased cell proliferation and tube-forming ability, increased LDH release, elevated ROS level, obvious cytoskeletal disruption, increased expression of IL-1β, IL-6, and TNF-α, and down-regulated mRNA and protein levels of PI3K and Akt. Compared with the model group, TaⅡ_A or EPCs-exos alone increased the cell proliferation and tube-forming ability, reduced LDH release, lowered the ROS level, repaired the damaged skeleton, decreased the expression of IL-1β, IL-6, and TNF-α, and up-regulated the mRNA and protein levels of PI3K and Akt. TaⅡ_A+EPCs-exos outperformed TaⅡ_A or EPCs-exos alone in regulating the above indexes. The results demonstrated that TaⅡ_A and EPCs-exos exerted a protective effect on POVPC-induced AVECs by activating the PI3K/Akt pathway, and the combination of the two had stronger therapeutic effect.
Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Signal Transduction ; Reactive Oxygen Species/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Endothelium, Vascular ; Oxidative Stress ; Endothelial Progenitor Cells ; RNA, Messenger/metabolism* ; Abietanes

Altitude ; Diabetes Mellitus, Type 2 ; Endothelial Progenitor Cells ; Glycated Hemoglobin A ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism*

Endothelial progenitor cells (EPCs) play an important role in diabetic vascular complications. A large number of studies have revealed that some clinical antihyperglycemics can improve the complications of diabetes by regulating the function of EPCs. Metformin can improve EPCs function in diabetic patients by regulating oxidative stress level or downstream signaling pathway of adenosine monophosphate activated protein kinase; Pioglitazone can delay the aging of EPCs by regulating telomerase activity; acarbose, sitagliptin and insulin can promote the proliferation, migration and adhesion of EPCs. In addition to lowering blood glucose, the effects of antihyperglycemics on EPCs may also be one of the mechanisms to improve the complications of diabetes. This article reviews the research progress on the regulation of EPC proliferation and function by antihyperglycemics.
Cell Movement/drug effects* ; Cells, Cultured ; Endothelial Progenitor Cells/drug effects* ; Humans ; Hypoglycemic Agents/pharmacology* ; Signal Transduction/drug effects*

OBJECTIVE: To investigate the effects of combined infusion of mesenchymal stem cells (MSC) and endothelial progenitor cells (EPC) on lung injury after hematopoietic stem cell transplantation (HSCT). METHODS: The experiment was divided into normal control group, irradiation group, bone marrow cell transplantation group (BMT group), BMT+EPC group, BMT+MSC group and BMT+EPC+MSC group. The model of HSCT was established, on the 30th day after transplantation, the mice were sacrificed. Then lung tissue was taken for testing. The mRNA expression levels of VEGF, IL-18, IL-12b were detected by RT-PCR, and protein expression level of NLRP3 was detected by Western blot. The expression of MPO and CD146 was observed by immunohistochemistry assay. RESULTS: The expression level of VEGF gene in BMT+EPC+MSC group was significantly higher than that in other groups (P＜0.01). The expression level of IL-18 and IL-12b gene was the highest in BMT group and the lowest in BMT+EPC+MSC group, and the difference was statistically significant (P＜0.05). HSCT could increase the expression of NLRP3 protein, and the BMT+EPC+MSC could significantly reduce the level of NLRP3 protein in lung cells, tending to normal. Compared with normal tissues, the BMT+EPC+MSC could improve the lung tissue structure more effectively, the expression of MPO positive cells was lower, and the expression of VEGF positive cells was higher. CONCLUSIONS The combined infusion of MSC and EPC can promote capillary regeneration, alleviate inflammation and promote lung repair after HSCT, which is superior to single EPC or MSC infusion.
Animals ; Endothelial Progenitor Cells ; Hematopoietic Stem Cell Transplantation ; Lung Injury ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stem Cells ; Mice ; Mice, Inbred C57BL

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

Obesity, diabetes, and cardiovascular diseases are increasing rapidly worldwide and it is therefore important to know the effect of exercise and medications for diabetes and obesity on adult stem cells. Adult stem cells play a major role in remodeling and tissue regeneration. In this review we will focus mainly on two adult stem/progenitor cells such as endothelial progenitor cells and mesenchymal stromal cells in relation to aerobic exercise and diabetes medications, both of which can alter the course of regeneration and tissue remodelling. These two adult precursor and stem cells are easily obtained from peripheral blood or adipose tissue depots, as the case may be and are precursors to endothelium and mesenchymal tissue (fat, bone, muscle, and cartilage). They both are key players in maintenance of cardiovascular and metabolic homeostasis and can act also as useful biomarkers.
Adipose Tissue ; Adult Stem Cells ; Adult ; Biomarkers ; Cardiovascular Diseases ; Diabetes Mellitus, Type 2 ; Endothelial Progenitor Cells ; Endothelium ; Exercise ; Hematopoietic Stem Cells ; Homeostasis ; Humans ; Mesenchymal Stromal Cells ; Obesity ; Regeneration ; Stem Cells

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

BACKGROUND/AIMS: NADPH (nicotinamide adenine dinucleotide phosphate) oxidase (NOX)-mediated oxidative stress plays a key role in promotion of oxidative injury in the cardiovascular system. The aim of this study is to evaluate the status of NOX in endothelial progenitor cells (EPCs) of hyperlipidemic patients and to assess the correlation between NOX activity and the functions EPCs. METHODS: A total of 30 hyperlipidemic patients were enrolled for this study and 30 age-matched volunteers with normal level of plasma lipids served as controls. After the circulating EPCs were isolated, the EPC functions (migration, adhesion and tube formation) were evaluated and the status of NOX (expression and activity) was examined. RESULTS: Compared to the controls, hyperlipidemic patients showed an increase in plasma lipids and a reduction in EPC functions including the attenuated abilities in adhesion, migration and tube formation, concomitant with an increase in NOX expression (NOX2 and NOX4), NOX activity, and reactive oxygen species production. The data analysis showed negative correlations between NOX activity and EPC functions. CONCLUSIONS: There is a positive correlation between the NOX-mediated oxidative stress and the dysfunctions of circulating EPCs in hyperlipidemic patients, and suppression of NOX might offer a novel strategy to improve EPCs functions in hyperlipidemia.
Adenine ; Cardiovascular System ; Endothelial Progenitor Cells* ; Humans ; Hyperlipidemias ; NADP* ; NADPH Oxidase ; Oxidative Stress* ; Oxidoreductases ; Plasma ; Reactive Oxygen Species ; Statistics as Topic ; Volunteers

To investigate the effects of adenosine triphosphate (ATP) on expression of inflammatory factors induced by lipopolysaccharide (LPS) in endothelial progenitor cells (EPCs), and to elucidate the possible mechanisms.
 Methods: Mononuclear cells were isolated from human umbilical cord blood by density gradient centrifugation, RT-PCR was performed to detect the expression of inflammatory factors induced by LPS (1 mg/mL) in EPCs, the effect of low concentration (5 μmol/L) of ATP on expression of IL-1β, MCP-1 and ICAM-1, and the effect of different concentrations (5, 50 μmol/L) of ATP on the expression of Toll-like receptor (TLR) 4, myeloid differentiation primary response protein 88 (MyD88) and CD14. Western blot was performed to detect expression of TLR4 regulated proteins MyD88 and CD14 or to detect the low concentration (1, 5 μmol/L) of ATP on the expression of TLR4, MyD88 and CD14 and the NF-κB signaling pathway.
 Results: EPCs highly expressed TLR4, and its ligand LPS (1 mg/mL) significantly upregulated mRNA expression of IL-1β, MCP-1 and ICAM-1 and protein expression of MyD88 and CD14 in a time-dependent manner (P<0.01), accompanied by activation of ERK and NF-κB signal pathway. ATP at low concentration (5 μmol/L) significantly inhibited LPS-induced mRNA expression of IL-1β, MCP-1 and ICAM-1(P<0.05), downregulated the LPS-induced protein expression of TLR4, MyD88 and CD14 in EPCs (P<0.05), and suppressed LPS-induced activation of NF-κB signaling pathway (P<0.05).
 Conclusion: ATP at low concentration may suppress LPS-induced expression of inflammatory factors in EPCs through negative regulation of the TLR4 signaling pathway.
Adenosine Triphosphate ; pharmacology ; Endothelial Progenitor Cells ; drug effects ; Gene Expression Regulation ; drug effects ; Humans ; Leukocytes, Mononuclear ; cytology ; Lipopolysaccharide Receptors ; genetics ; Lipopolysaccharides ; pharmacology ; Myeloid Differentiation Factor 88 ; genetics ; NF-kappa B ; metabolism ; Signal Transduction ; drug effects ; Toll-Like Receptor 4 ; genetics

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