ObjectiveTo explore optimal conditions of isolation, culture and labeled with superparamagnetic iron oxide (SPIO) in vitro of rat bone marrow endothelial progenitor cells, and lay the foundations for the further EPCs tracer study in vivo. MethodsThe EPCs derived from rat bone marrow were isolated and cultured by using density gradient centrifugation, which were labeled with different concentrations SPIO, Prussian blue staining was used to detect the cells labeling rate, MTT assay was used to detect the cells proliferation activity, and Trypan blue staining was used to detect the cells vitality. ResultsEPCs gradually growed in monolayer arrangement about 7 d after cultured. When the concentration of SPIO was 50μg/mL, the highest labeling rate of Prussian blue staining was 90%, the growth state of labeled EPCs were good, and could normal adherent growth and passage. At this time, the cell viability and proliferation activity were the highest through trypan blue staining and MTT assay. ConclusionsEPCs can be labeled with SPIO easily and efficiently when the concentration was 50μg/mL?without interference on the viability and proliferation activity, which lay the foundations for the further EPCs tracer study in vivo.
ObjectiveTo compare the biological features of early and late endothelial progenitor cells (EPCs) by isolating and culturing early and late EPCs from the human peripheral blood so as to find some unique properties of EPCs and to propose a suitable strategy for EPCs identification. MethodsMononuclear cells were isolated from the human peripheral blood using density gradient centrifugation. Then, the cells were inoculated in human fibronectin-coated culture flasks and cultured in endothelial cell basal medium 2. After 4-7 days and 2-3 weeks culture, early and late EPCs were obtained respectively. The morphology, proliferation potential, surface markers, cytokine secretion, angiogenic ability, and nitric oxide (NO) release were compared between 2 types of EPCs. Meanwhile, the human aortic endothelial cells (HAECs) were used as positive control. ResultsThe morphology of early and late EPCs was different:early EPCs formed a cell cluster with a spindle shape after 4-7 days of culture, and late EPCs showed a cobblestone appearance. Late EPCs were characterized by high proliferation potential and were able to form capillary tubes on Matrigel, but early EPCs did not have this feature. Both types EPCs could ingest acetylated low density lipoprotein and combine with ulex europaeus Ⅰ. Flow cytometry analysis showed that early EPCs did not express CD34 and CD133, but expressed the CD14 and CD45 of the hematopoietic stem cell markers;however, late EPCs expressed CD31 and CD34 of the endothelial cell markers, but did not express CD14, CD45, and CD133. By RT-PCR analysis, the expressions of vascular endothelial growth receptor 2 and vascular endothelial cadherin in early EPCs were significantly lower than those in the late EPCs and HAECs (P<0.05), but no significant difference was found in the expression of von Willebrand factor and endothelial nitric oxide synthase (eNOS) between 2 type EPCs (P>0.05). The concentrations of vascular endothelial growth factor, granulocyte colony-stimulating factor, and interleukin 8 were significantly higher in the supernatant of early EPCs than late EPCs (P<0.05). Western blot assay indicated eNOS expressed in both types EPCs, while the expression of eNOS in late EPCs was significantly higher than early EPCs at 5 weeks (P<0.05). Both cell types could produce similar amount of NO (P>0.05). ConclusionThe expression of eNOS and the production of NO could be used as common biological features to identify EPCs, and the strategy of a combination of multiple methods for EPCs identification is more feasible.
Objective To observe the effects of Galectin-3 on proliferation of vascular endothelial cells derived from peripheral blood endothelial progenitor cells. Methods The cultured peripheral blood endothelial progenitor cells in vitro were isolated and purified from human peripheral blood, and the cells were differentiated into vascular endothelial cells. Then the cells were cultivated with the galectin-3 of different concentrations, and to observe the proliferation of endothelial cells derived from peripheral blood endothelial progenitor cells. Results The abilities of proliferation of endothelial cells derived from peripheral blood endothelial progenitor cells of 0.1, 1.0, 2.5, 5.0, and 10.0 μg/ml groups were higher than that of 0 μg/ml group, there were not statistic significance of the differences between the 0.1，1.0, 2.5, and 0 μg/ml groups （P＞0.05）. But the abilities of proliferation of 5.0 and 10.0 μg/ml groups were obviously higher than that of 0, 0.1, 1.0, and 2.5 μg/ml groups （P＜0.05）, and the abilities of proliferation of 10.0 μg/ml group was also higher than that of 5.0 μg/ml group （P＜0.05）. Conclusion Galectin-3 can promote the proliferation of endothelial cells derived from peripheral blood endothelial progenitor cell.
Immobilization of CD34 antibody on ferroferric oxide magnetic nanoparticles was achieved by the traditional carboxyl-amine conjugation reaction. Fourier transform infrared spectroscopy (FT-IR), nanoparticle size analysis (dynamic light scattering and transmission electron microscope), and other testing methods were used to detect the surface modified magnetic nanoparticles. The endothelial progenitor cells (EPCs) were cultured with the surface modified magnetic nanoparticles to evaluate cell compatibility and the combination effect of nanoparticles on EPCs in a short period of time. Directional guide of the surface modified magnetic nanoparticles to EPCs was evaluated under applied magnetic field and simulated dynamic flow condition. The results showed that the magnetic nanoparticles were successfully modified with CD34 antibody, which had good cell compatibility within a certain range of the nanoparticle concentrations. The surface modified nanoparticles can combine with EPCs effectively in a short time, and those nanoparticles combined EPCs can be directional guided under the magnetic field in the dynamic flow environment.
Objective To evaluate effect of hypoxia condition (1% or 5% oxygen concentration) on proliferation, adhesion, migration, or viability ability of bone morrow-derived endothelial progenitor cells (EPCs). Methods The bone marrow mononuclear cells of SD rat were acquired with density gradient centrifugation method. They were cultured, induced, and differentiated to the EPCs. Then they were cultured respectively in three different oxygen concentrations (1%, 5%, or 21%). On the 3rd day and the 7th day, the effects of the different oxygen concentrations (1%, 5%, or 21%) on the EPCs’ neovascularization characteristics (including proliferation, adhesion, migration, and viability abilities) were evaluated. Results Whether cultured for the 3rd day or 7th day, the proliferation, adhesion, migration, and viability abilities of the cultured cells in the 1% and 5% oxygen concentrations were significantly better than those of the cultured cells in the 21% oxygen concentration (all P<0.05). Except for the proliferation ability of the cultured cells in the 5% oxygen concentration was significantly better than that of the cultured cells in the 1% oxygen concentration (P<0.05) on the 3rd day, and the adhesion ability on the 3rd day and the proliferation ability on the 7th day had no significantly differences, the other abilities (adhesion, migration, and viability abilities) of the cultured cells in the 1% oxygen concentration were significantly better than those of the cultured cells in the 5% oxygen concentration (allP<0.05). Conclusion Different oxygen concentration has an effect on proliferation, adhesion, migration, or viability ability of bone morrow-derived EPCs, appropriate hypoxia condition (1% or 5% oxygen concentration ) can enhance these abilities.
ObjectiveTo review the current progresses in purification strategies, biological characters, and functions of endothelial progenitor cells (EPCs) derived extracellular vesicles (EVs) (EPC-EVs). MethodsRecent relevant publications on the EPC-EVs were extensively reviewed, analyzed, and summarized. ResultsEPC-EVs are usually isolated by differential centrifugation and exhibit a homogenous pattern of spheroid particles with a diameter ranging from 60 to 160 nm under transmission electron microscopy. EPC-EVs are positive for cell-surface markers of EPCs (CD31, CD34, and CD133), and negative for markers of platelets (P-selectin and CD42b) and monocytes (CD14). Recent studies have shown the effectiveness of EPC-EVs in ischemic injuries, anti-Thy1 glomerulonephritis, and cardiomyocyte hypertrophy, and also shown their predictive role in cardio-cerebral-vascular diseases. ConclusionAn alluring prospect exists on the EPC-EVs-related research. Further studies are required to decipher the composition of EPC-EVs and their precise role in pathophysiological processes, and to investigate the molecular mechanisms for their targeting and function.
Objective To examine the effect of endothelial progenitor cell (EPC) on lung ischemia-reperfusion injury (LIRI). Methods Twenty-four recipients were randomized into 3 groups including a sham group, a LIRI group, and an EPC group. Rats in the sham group only received anesthesia. Rats in the LIRI and EPC groups received left lung transplantation and received saline or EPC immediately after reperfusion. The partial pressure of oxygen to fraction of inspiratory oxygen (PaO2/FiO2) ratio, wet-to-dry weight ratio and protein levels in the transplanted lung and inflammation-related factors levels in serum were examined. Histological change of transplanted lung were analyzed. The nuclear factor (NF)-κB in the transplanted lung was detected. Results Compared with the LIRI group, the PaO2/FiO2 ratio dramaticly increased, and the wet-to-dry weight ratio and protein level significantly decreased by EPC after reperfusion. The lung histological injury was attenuated by EPC. The pro-inflammatory factors in serum were down-regulated, whereas IL-10 was up-regulated in the EPC group. The expression of NF-κB was decreased by EPC. Conclusion EPC ameliorated LIRI after lung transplantation. The protection of EPC partly associated with anti-inflammation.
Objective To observe the adhesion and prol iferation of late endothel ial progenitor cells (EPCs) planted on nanoporous PLLA scaffold in vitro and to provide a new approach that optimizes tissue engineered material. Methods Male and female New Zealand rabbits (weight 2.5-3.0 kg) were used. Isolated late EPCs from rabbit peri pheral blood were cultured. Electrostatic spinning technique was adopted to prepare misal igned nanofibers, al igned nanofibers and super-al igned nanofibers, and low temperature plasma technique was appl ied to prepare misal igned membrane, al igned membrane and super-al igned membrane. After being divided into group A (cells only), B (misal igned membrane), C (normal membrane), D (al igned membrane) and E (super-al igned membrane), the primary late EPCs (1 × 105/mL) werecultured on scaffolds and MTT method was used to detect cell prol iferation abil ity at 3, 5, 7, 9, 11, 13, 15 and 17 days afterculture. After being divided into group A (misal igned membrane), B (normal membrane), C (al igned membrane) and D (superal igned membrane), precipitation method was appl ied to detect cell adhesion rate at 4, 12 and 24 hours after compound culture, and the morphologic changes of cells were observed at 4, 24 and 72 hours after compound culture. Results Fiber diameters in nanofibrous PLLA scaffolds were 300-400 nm, with a porosity rate of above 90%. At 3, 5, 7, 9, 11, 13, 15 and 17 days after culture, A value of each group was increased with time and the cells in each group grew well, showing there was no significant difference between group A and group B at each time point (P gt; 0.05 ); during the period of 7-15 days after culture, the difference between groups C, D and E and groups A and B was significant (P lt; 0.05). At 4 hours after compound culture, the adhesion rate of group A was superior to that of groups B, C and D (P lt; 0.05); at 12 and 24 hours after compound culture, the adhesion rate of groups B, C and D was remarkably higher than that of group A (P lt; 0.05); significant difference was noted in each group between the time point of 4 hours and the time point of 12 and 24 hours after compound culture (P lt; 0.05), but no significant difference between 12 hours and 24 hours was detected (P gt; 0.05). Morphology observation demonstrated that cells grew well on the scaffolds, the cells in groups A and B grew sporadically and disorderly, while the cells in groups C and D attached and al igned along fiber and prol iferated, with an excretion of ECM. Group D was better at maintaining cell morphology. Conclusion Al igned and superal igned nanofibers of PLLA scaffold can promote the adhesion and prol iferation of seed cells on the scaffold and maintain good cell morphology, which is an appropriate candidate scaffold material for blood vessel tissue engineering. Late EPCs is an ideal cell source for blood vessel tissue engineering.
ObjectiveTo review the research progress of the co-culture system for constructing vascularized tissue engineered bone. MethodsThe recent literature concerning the co-culture system for constructing vascularized tissue engineered bone was reviewed, including the selection of osteogenic and endothelial lineages, the design and surface modification of scaffolds, the models and dimensions of the co-culture system, the mechanism, the culture conditions, and their application progress. ResultsThe construction of vascularized tissue engineered bone is the prerequisite for their survival and further clinical application in vivo. Mesenchymal stem cells (owning the excellent osteogenic potential) and endothelial progenitor cells (capable of directional differentiation into endothelial cell) are considered as attractive cell types for the co-culture system to construct vascularized tissue engineered bone. The culture conditions need to be further optimized. Furthermore, how to achieve the clinical goals of minimal invasion and autologous transplantation also need to be further studied. ConclusionThe strategy of the co-culture system for constructing vascularized tissue engineered bone would have a very broad prospects for clinical application in future.
目的：观测外周造血干/祖细胞采集术对造血干/祖细胞采集的临床效果。方法：对14例患者及11例健康捐献者进行外周造血干/祖细胞采集术52例次，观测采集前后外周血WBC、RBC、Hb、Hct、Plt，采集后CD34+细胞、CFU-GM量，以及不良反应。结果：经过1～3次采集，采集量达到造血干/祖细胞移植所需量，不良反应轻微。结论：外周血干/祖细胞采集具有处理量大,副作用小,安全高效等优点。