Peripheral Blood-derived Endothelial Progenitor Cells Research Articles

A combined cell and growth factor delivery for the repair of a critical size tibia defect using biodegradable hydrogel implants.

The ability to repair critical‐sized long‐bone injuries using growth factor and cell delivery was investigated using hydrogel biomaterials. Physiological doses of the recombinant human bone morphogenic protein‐2 (rhBMP2) were delivered in a sustained manner from a biodegradable hydrogel containing peripheral human blood‐derived endothelial progenitor cells (hEPCs). The biodegradable implants made from polyethylene glycol (PEG) and denatured fibrinogen (PEG‐fibrinogen, PF) were loaded with 7.7 μg/ml of rhBMP2 and 2.5 × 106 cells/ml hEPCs. The safety and efficacy of the implant were tested in a rodent model of a critical‐size long‐bone defect. The hydrogel implants were formed ex‐situ and placed into defects in the tibia of athymic nude rats and analyzed for bone repair after 13 weeks following surgery. The hydrogels containing a combination of 7.7 μg/ml of rhBMP2 and 2.5 × 106 cells/ml hEPCs were compared to control hydrogels containing 7.7 μg/ml of rhBMP2 only, 2.5 × 106 cells/ml hEPCs only, or bare hydrogels. Assessments of bone repair include histological analysis, bone formation at the site of implantation using quantitative microCT, and assessment of implant degradation. New bone formation was detected in all treated animals, with the highest amounts found in the treatments that included animals that combined the PF implant with rhBMP2. Moreover, statistically significant increases in the tissue mineral density (TMD), trabecular number and trabecular thickness were observed in defects treated with rhBMP2 compared to non‐rhBMP2 defects. New bone formation was significantly higher in the hEPC‐treated defects compared to bare hydrogel defects, but there were no significant differences in new bone formation, trabecular number, trabecular thickness or TMD at 13 weeks when comparing the rhBMP2 + hEPCs‐treated defects to rhBMP2‐treated defects. The study concludes that the bone regeneration using hydrogel implants containing hEPCs are overshadowed by enhanced osteogenesis associated with sustained delivery of rhBMP2.

Comparative Preliminary Analysis of Umbilical Cord Blood-, Healthy Adult Peripheral Blood- and Myocardial Infarct Peripheral Blood-Derived Endothelial Progenitor Cells

BACKGROUND: Cardiovascular disease is a leading cause of death globally with the 287,000 deaths per years, characterized by declining of heart function caused by the reduction of heart capacity and lead to heart failure. Cell therapy using endothelial progenitor cells (EPCs) has a big potential for cardiovascular regeneration. EPCs are cells that have ability to differentiate into endothelial cells that can be mobilized and integrated into the defected blood vessel by angiogenesis.
 AIM: We aimed to seek the superior EPCs derived from MNCs for functional improvement of advanced heart failure patient by cell therapy using EPCs.
 MATERIALS AND METHODS: We did preliminary analysis to compare umbilical cord blood (UCB), healthy adult peripheral blood (PB)-, and myocardial infarct PB-derived EPCs characteristic and surface phenotypes. Different sources of each EPCs mononuclear cells were characterized by the expression of endothelial (cluster of differentiation [CD] 31, acethylated low-density lipoprotein, and von Willebrand) and hematopoietic stem cell (CD45, CD34, and CD133) surface markers with flow cytometry.
 RESULTS: In this study, EPCs and the conditioned medium (CM) have been produced and characterized in laboratory scale by comparing several sources of EPCs for instance UCB, PB from healthy people, and patients with myocardial infarction. We have shown that EPC characterizations from each group were not significantly different, but vascular endothelial growth factor and hepatocyte growth factor in UBC-derived CM-EPCs were higher than in PB.
 CONCLUSION: In conclusion, the UBC-derived EPCs might have a better potential for cardiovascular regeneration.

Conditioned media from endothelial progenitor cells cultured in simulated microgravity promote angiogenesis and bone fracture healing

BackgroundParacrine signaling from endothelial progenitor cells (EPCs) is beneficial for angiogenesis and thus promotes tissue regeneration. Microgravity (MG) environment is found to facilitate the functional potentials of various stem or progenitor cells. The present study aimed to elucidate the effects of MG on pro-angiogenic properties and fracture repair capacities of conditioned media (CM) from EPCs.MethodsHuman peripheral blood-derived EPCs were cultured under MG or normal gravity (NG) followed by analysis for angiogenic gene expression. Furthermore, the serum-free CM under MG (MG-CM) or NG (NG-CM) were collected, and their pro-angiogenic properties were examined in human umbilical vein endothelial cells (HUVECs). In order to investigate the effects of MG-CM on fracture healing, they were injected into the fracture gaps of rat models, and radiography, histology, and mechanical test were performed to evaluate neovascularization and fracture healing outcomes.ResultsMG upregulated the expression of hypoxia-induced factor-1α (HIF-1α) and endothelial nitric oxide synthase (eNOS) and promoted NO release. Comparing to NG-CM, MG-CM significantly facilitated the proliferation, migration, and angiogenesis of HUVECs through NO-induced activation of FAK/Erk1/2-MAPK signaling pathway. In addition, MG-CM were verified to improve angiogenic activities in fracture area in a rat tibial fracture model, accelerate fracture healing, and well restore the biomechanical properties of fracture bone superior to NG-CM.ConclusionThese findings provided insight into the use of MG bioreactor to enhance the angiogenic properties of EPCs’ paracrine signals via HIF-1α/eNOS/NO axis, and the administration of MG-CM favored bone fracture repair.Graphical abstract

Identification of Potential Hub Genes and Signal Pathways Promoting the Distinct Biological Features of Cord Blood-Derived Endothelial Progenitor Cells Via Bioinformatics.

Background: Numerous studies, ranging from the alleviation of tissue ischemia to the assessment of cancer prognosis, have demonstrated the fundamental biological differences between human umbilical cord blood-derived endothelial progenitor cells (CB-EPCs) and adult peripheral blood-derived endothelial progenitor cells (PB-EPCs). However, the underlying molecular mechanisms that produce these differences are not clear.The purpose of this study was to identify potential hub genes, key protein interactive networks, and correlated signal pathways unique to CB-EPC biology via bioinformatic methods. Materials and Methods: We selected the microarray dataset GSE39763 and identified the differentially expressed genes (DEGs) using the "limma" package in the RStudio software. These DEGs were annotated by gene ontology enrichment analyses and signal pathway analyses. A protein-protein interaction (PPI) analysis was then performed to construct PPI networks and identify a hub protein module. We further validated candidate DEGs from the selected module in the gene expression profiling interactive analysis (GEPIA) database because the DEGs were enriched in cancer pathways. Results: Setting an adjusted p-value <0.01 and |Log2 fold change (FC)| ≥ 2 as cutoff criteria, a total of 346 DEGs, including 314 upregulated genes and 32 downregulated genes in CB-EPCs, were identified. Expression of the genes encoding the AT-Hook Containing Transcription Factor 1 (AHCTF1), the Cancer Susceptibility Candidate 5 (CASC5), the Centromere Protein C (CENPC), the Centromere Protein E (CENPE), the Centromere Protein F (CENPF), the NUF2 Component of NDC80 Kinetochore Complex (NUF2), the RAN-Binding Protein 2 (RANBP2), the Shugoshin-like 2 (SGOL2), the Structural Maintenance of Chromosomes 3 (SMC3), and the Spindle Apparatus Coiled-Coil Protein 1 (SPDL1) proteins were specifically associated with CB-EPCs. Except for CENPC, the other nine genes' expression are all associated with a poorer overall survival rate in cancers. The expression levels of the CENPF and NUF2 genes in tumor patients were significantly higher than those in the controls. Conclusion: The CB-EPCs express genes with greater potential for proliferation and increased migration compared to PB-EPCs; in this regard they are similar to cancer cells.

MicroRNA-646 inhibits angiogenesis of endothelial progenitor cells in pre-eclamptic pregnancy by targeting the VEGF-A/HIF-1α axis.

Pre-eclampsia is a complication that occurs during pregnancy, the pathological feature of which is a change in vascular endothelial homeostasis. microRNA (miR)-646 is an anti-angiogenic miRNA that has been indicated to exhibit potential anti-angiogenic effects in endothelial cells cultured in vitro and in ischemia-induced angiogenesis. However, whether miR-646 has therapeutic potential in placental angiogenesis in pre-eclampsia remains to be determined. In the current study, human peripheral blood-derived endothelial progenitor cells (EPCs) were isolated to study the coordination between miR-646, vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor (HIF)-1α expression in preeclampsia EPCs. EPCs were isolated from human peripheral blood to demonstrate a potential interaction between miR-646 and targets (VEGF-A) in vitro. The number of EPCs and the expression of miR-646 in patients with preeclampsia was detected, and the effects of miR-646 on EPC function and preeclampsia angiogenesis was assessed. Clinical specimens demonstrated that miR-646 expression was enhanced in pregnancy with preeclampsia. The results indicated that miR-646 suppressed EPCs multiplication, differentiation and migration. miR-646 was observed to exert an anti-angiogenic function by suppressing the expression of angiogenic cytokines VEGF-A and HIF-1α. Additionally, luciferase results displayed that miR-646 downregulated VEGF-A expression by directly binding to a specific sequence in its 3'-untranslated region. The results of the current study demonstrated that the miR-646/VEGF-A/HIF-1α axis is significant for angiogenic properties of EPCs in vitro and in vivo placental vasculogenesis. The results of the present study provide a new insight into microRNA regulation of vessel homeostasis and angiogenesis, and a basis for alternative treatments for patients with pre-eclampsia.

Oxygen Tension-Controlled Matrices with Osteogenic and Vasculogenic Cells for Vascularized Bone Regeneration In Vivo.

Despite recent progress, segmental bone defect repair is still a significant challenge in orthopedic surgery. While bone tissue engineering approaches using biodegradable matrices along with bone/blood vessel forming cells offered improved possibilities, current regenerative strategies lack the ability to achieve vascularized bone regeneration in critical-sized/segmental bone defects. In this study, we introduced and evaluated a two-pronged approach for vascularized bone regeneration in vivo. The goal was to demonstrate vascularized bone formation using oxygen tension-controlled (OTC) matrices seeded with bone and blood vessel forming cells. OTC matrices were coimplanted with rabbit mesenchymal stem cells (MSCs) and peripheral blood-derived endothelial progenitor cells (PB-EPCs) to demonstrate the osteogenic and vasculogenic differentiation of these cells, postseeding on a matrix, especially deep inside the matrix pore structure. Matrices coimplanted with varied rabbit MSC and PB-EPC ratios (1:4, 1:1, and 4:1) were assessed in a nude mouse subcutaneous implantation model to determine a coimplantation ratio with superior osteogenic as well as vasculogenic properties. The implants were analyzed, at week 8, for endothelial (CD31 and Von Willebrand factor [vWF]) and osteogenic marker (RunX2 and Col I) staining qualitatively and collagen deposition and number of vessel formation quantitatively. Results from these experiments established MSC-to-PB-EPC ratio 1:1 as the best coimplantation ratio. OTC matrix with 1:1 coimplantation ratio was assessed for segmental bone defect repair in a rabbit critical-sized bone defect model. The group under investigation was OTC matrix, and the matrix was seeded with MSCs, EPCs, or MSCs:EPCs in a 1:1 ratio. Explants at week 12 were evaluated for bone defect repair via micro-CT and histology. Results from rabbit in vivo experiments show enhanced mineralization and vascularization for the 1:1 coimplantation group. Overall, the study establishes a two-pronged approach involving OTC matrix and effective progenitors for large-area and vascularized bone regeneration.

Establishment of an Early Vascular Network Promotes the Formation of Ectopic Bone.

Vascularization is crucial for the induction of bone formation. In this study, we investigated the application of two subtypes of peripheral blood-derived endothelial progenitor cells (EPCs) to stimulate vessel formation in ectopic bone constructs. Early and late outgrowth EPCs (E-EPC and L-EPC, respectively) were characterized for their ability to form network structures in vitro and perfused vessels subcutaneously in mice. Only L-EPCs showed the formation of fully connected networks on Matrigel two-dimensional (2D) angiogenesis assays. The presence of multipotent stromal cells (MSCs) inhibited network formation in 2D assays, but stimulated network formation in three-dimensional plugs. In vivo studies revealed that at 2 weeks, the highest incidence of formed perfused vessels was reached by implanted E-EPC/MSC constructs and this could be attributed to the presence of E-EPCs. L-EPCs displayed a significantly lower frequency of blood vessel formation than E-EPCs and this was accompanied by a lowering of total luminal area densities. Nevertheless, combined E-EPC/L-EPC application somewhat increased the percentage incidence of perfused vessels. After 6 weeks, differences in vascularization were still obvious as all three EPC-based constructs contained higher numbers of perfused vessels than constructs containing MSCs alone. Bone was formed in all constructs at an incidence that coincided with high density of perfused vessels after 2 weeks. Altogether, our findings suggest the differential establishment of vascular networks by E-EPCs and L-EPCs and suggest the importance of early vasculogenesis in ectopic bone formation.

Tea Flavonoids Induced Differentiation of Peripheral Blood-derived Mononuclear Cells into Peripheral Blood-derived Endothelial Progenitor Cells and Suppressed Intracellular Reactive Oxygen Species Level of Peripheral Blood-derived Endothelial Progenitor Cells

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.

The co-culture of peripheral blood-derived endothelial progenitor cells and mesenchymal stem cells on three-dimensional porous strontium-doped calcium polyphosphate scaffold for construction of vascularized engineering bone

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Endothelial progenitor cells derived from the peripheral blood of halfpipe- snowboarding athletes display specific functional properties.

In this study, we compared the functional properties of endothelial progenitor cells (EPCs) derived from halfpipe-snowboarding athletes who train under hyperoxic conditions with those derived from normal subjects who lived under normoxic conditions. Peripheral blood-derived EPCs were isolated from both halfpipe-snowboarding athletes and normal humans. Cellular growth dynamics, lipoprotein transport, and gene expression of cultured EPCs were compared between the two groups of cells. Results indicate that cytoactivity of EPCs from athletes was higher than that of EPCs from control subjects. This study suggests that function of EPCs from snowboarding athletes may be better than that of EPCs from normal humans, which demonstrates the benefits of training under hyperoxic conditions.

Intra-carotid arterial administration of autologous peripheral blood-derived endothelial progenitor cells improves acute ischemic stroke neurological outcomes in rats

ObjectiveWe tested the hypothesis that transfusion of autologous peripheral blood-derived endothelial progenitor cells (PBDEPC) via the internal carotid artery could reduce brain-infarct zone (BIZ) and neurological deficit in rats following acute ischemic stroke (IS) induced by 50-min left middle cerebral artery occlusion. DesignAdult male Sprague–Dawley rats (n=60) were equally divided into group 1 [sham control (SC)], group 2 [SC-PBDEPC (5.7×106/kg)], group 3 (IS), group 4 [IS-low-dose PBDEPC (1.7×106/kg)], group 5 [IS-high-dose PBDEPC (5.7×106/kg)]. Groups 2 to 5 received G-CSF (35μg/kg subcutaneously) for 4days before drawing blood for PBDEPC culture. Measurements and main resultsBy day 90, BIZ determined by histopathology (area) and brain MRI (volume) were highest in group 3, lowest in groups 1 and 2, higher in group 4 than in group 5 (all p<0.0001), and not significantly different between groups 1 and 2. Sensorimotor functional results exhibited an opposite pattern of BIZ among groups 3 to 5 (p<0.005). Angiogenesis biomarkers (SDF-1α, CXCR4, VEGF, angiopoietin-1) significantly increased progressively from groups 1 and 2 to group 5 (all p<0.0001). Oxidative-stress (NOX-1, NOX-2, oxidized protein), apoptotic (cleaved caspase 3 and PARP, mitochondrial Bax), inflammatory (MMP-9, TNF-α, AQP-4, GFAP, iNOS), and brain-damaged (cytosolic cytochrome-C) biomarkers showed an identical pattern, whereas anti-inflammatory (Bcl-2), mitochondrial preservation (mitochondrial cytochrome-C, PGC-1α), and endothelial function (CD31+, vWF+, eNOS) biomarkers, and vessel density showed an opposite pattern of BIZ among these five groups (all p<0.001). ConclusionHigher-dose was superior to lower-dose EPC treatment for reducing BIZ and improving neurological functional outcome.

Isolation and characterization of peripheral blood-derived endothelial progenitor cells from broiler chickens

Peripheral blood-derived endothelial progenitor cells (EPCs) have been extensively studied in mammals but the isolation and characterization of EPCs in avian species have not been reported. In this study, chicken peripheral blood mononuclear cells (PBMNCs) were cultured under conditions favoring endothelial-specific differentiation for 2 weeks. One heterogeneous cell population dominated by spindle-shaped cells (early EPCs) and one homogeneous cell population exhibiting cobblestone-like morphology (endothelial outgrowth cells, EOCs) appeared sequentially.Quantitative polymerase chain reaction (PCR) showed the expression of several progenitor and endothelial cell markers such as CD133, VEGFR-2 and CD31 in both cell populations. However, CD34, another progenitor marker, was undetectable in either freshly isolated PBMNCs or cultured cells. The endothelial phenotype of the EOCs was further identified by acetylated low-density lipoprotein/lectin double staining, and in vitro tube formation. Collectively, these data demonstrate that chicken EPCs can be isolated and cultured from PBMNCs and suggest that EPCs obtained from peripheral blood may originate mainly from the CD34− subpopulation.

Proliferation of Peripheral Blood-derived Endothelial Progenitor Cells from Stable Angina Subjects

BACKGROUND: A population of circulating Endothelial Progenitor Cells (EPCs) has been reported to play important role in maintaining endothelial function and integrity. Since EPCs culture is crucial and an optimized medium is currently available. Therefore we conducted a study to investigate whether stable angina subjects peripheral blood-derived EPCs could be cultured in this medium. Here, we performed study to detect EPCs characteristics and extracellular signalregulated kinase (Erk)1/2 Mitogen-Activated Protein Kinase (MAPK) pathway as possible underlying pathway for EPCs proliferation.METHODS: Peripheral blood EPCs from 8 stable angina subjects were cultured in an optimized medium with/without addition of supplement for 1 or 3 days. Then, the membrane of cultured EPCs were detected with immunofluorescence method for CD34, Vascular Endothelial Growth Factor Receptor 2 (VEGFR-2) and CD133. Colony forming unit (CFU) enumeration was performed. XTT Cell proliferation assay was performed to assess EPCs growth after 1 and 3-days culture. The western blot analysis was performed to detect possible activation of Erk1/2 MAPK.RESULTS: Number of EPCs and CFU cultured for 3 days were significantly higher than the ones cultured for 1 day (p=0.012). EPCs membrane markers from stable angina subjects were detected as well as CFUs were formed. There were significant increase of EPCs number, CFUs number and phosphorylated-Erk2 amount when the groups with and without supplement were compared (p&lt;0.05). Meanwhile U0126, a MAPK Erk1/2 (MEK1/2) inhibitor, significantly inhibited the supplement-induced EPCs number, CFUs number and phosphorylated-Erk2 amount (p&lt;0.05).CONCLUSION: Our results showed that ERK2 MAPK signaling pathway might play an important role in supplement-induced peripheral blood EPCs proliferation in subjects with stable angina.KEYWORDS: endothelial progenitor cell, EPC, p42, Erk2, proliferation

Mesenchymal Stem Cells and Endothelial Progenitor Cells Stimulate Bone Regeneration and Mineral Density

Alveolar bone deficiency is a major clinical problem in maxillofacial reconstructive surgery. The available surgical techniques to enhance extracortical bone augmentation are generally unpredictable and not satisfying. The aim of the present study is to quantify extracortical bone augmentation and tissue mineral density (TMD) after cotransplantation of peripheral blood-derived endothelial progenitor cells (EPCs) and bone marrow-derived mesenchymal stem cells (MSCs) by microcomputed tomography (micro-CT). Bone regeneration was tested in the guided bone regeneration rat calvaria model. Gold domes filled with beta tricalcium phosphate (β-TCP; control [CNT]) or β-TCP mixed with 5 × 10(5) rat EPCs and 5 × 10(5) rat osteogenic transformed MSCs (EPC/otMSCs) were fixed to the exposed calvaria. Rats were sacrificed after 3 months. Bone volume fraction (BV/TV) and TMD were analyzed using micro-CT. In the middle of the dome, a cylindrical region of interest was defined (it represents the area in which implants are placed) and subdivided into bottom, middle, and top to analyze the effect of the distance from the calvaria on bone formation. In the whole cylinder, BV/TV and TMD were higher in the EPC/otMSC group compared with CNT (BV/TV: 22.9% ± 4.4% versus 29.1 ± 2.2%, P = 0.02; TMD: 937.79 ± 18.68 versus 960.78 ± 5.8 mgHA/ccm, P = 0.03; CNT versus EPC/otMSC, respectively). In each of the three subregions, BV/TV was higher in the EPC/otMSC group compared with CNT (top: 20.25% ± 2.4% versus 23.74% ± 1.5%, P = 0.007; middle: 23.2% ± 4.8% versus 28% ± 2.2%, P = 0.05; bottom: 25.3% ± 7.6% versus 35.7% ± 4.9%, P = 0.02; CNT versus EPC/otMSC, respectively). Three-dimensional quantification by micro-CT demonstrated that cotransplantation of EPC/otMSCs significantly improved bone formation and mineral density.

γ-Irradiated cord blood MNCs: Different paracrine effects on mature and progenitor endothelial cells

Cell-based therapies have been employed to promote neovascularization mainly through the release of paracrine factors inhibiting apoptosis and supporting migration and proliferation of resident differentiated cells. We tested in vitro pro-angiogenic effects of apoptotic cord blood-derived mononuclear cells (CB-MNCs) and their conditioned medium (CM) on mature endothelial cells (HUVECs) and peripheral blood-derived endothelial progenitor cells (ECFCs).CB-MNCs were γ-irradiated to induce apoptosis and cultured for 72h to obtain the release of CM. MNCs viability, evaluated by flow cytometry, decreased progressively after γ-irradiation reaching 41% at 72h. γ-Irradiated MNCs (γMNCs) released increasing amounts of EGF, PDGF-AB and VEGF in their CM over time, as assessed by ELISA. γ-MNCs and their CM enhanced capillary-like network formation (in a dose-dependent and time-persistent manner), proliferation and migration of HUVECs in vitro, while they primed capillary-like network formation (dose-independent and not time-persistent) and induced migration but did not support proliferation of ECFCs.Our data support the hypothesis of paracrine mechanism as prevalent in regenerative medicine and demonstrate the efficacy of MNCs secretome in inducing neovascularization. To our knowledge, this is the first paper highlighting differential pro-angiogenic effects of CM on mature and progenitor endothelial cells, adding a tile in the understanding of mechanisms involved in neovascularization.

Peripheral Blood-Derived Endothelial Progenitor Cells Enhance Vertical Bone Formation

This study presents a novel cell-based approach for extra-cortical bone regeneration. To enhance vertical bone formation by combining guided bone regeneration and transplantation of peripheral blood-derived endothelial progenitor cells (EPCs) in a rat calvaria model. EPCs were isolated from peripheral blood of inbred rats. Gold domes (7 mm radius, 5 mm height) were filled with β-tricalcium phosphate (βTCP) mixed with 5 × 10(5) EPC. Domes filled with βTCP served as control (CNT). Rats were sacrificed after 3 months. Vertical bone augmentation was analyzed using histology, histomorphometry, and microcomputed tomography (μCT). In all rats, hard tissue filled the space under the dome. Histomorphometric analysis revealed that EPC transplantations doubled vertical bone height (EPC 4.04 ± 0.22 mm vs CNT 2.29 ± 0.22 mm, p ≤ .001). EPC also caused ∼50% increase in bone area fraction (EPC 47.3 ± 3.1% vs CNT 31.1 ± 2.7%, p ≤ .003). μCT results also showed that bone volume fraction (BV/TV) was higher in EPC group (p = .0169). In both groups, BV/TV declined from the bottom to the top of the samples. No differences in tissue mineral density were found between EPC and CNT groups. EPC transplantation significantly improved bone formation especially in the areas that are remote from the original bone.

Application of peripheral-blood-derived endothelial progenitor cell for treating ischemia-reperfusion injury and infarction: a preclinical study in rat models

BackgroundOur aim was to explore the therapeutic effects of peripheral blood-derived endothelial progenitor cells (PB-EPC) in cardiac ischemia-reperfusion infarction models in rats and in in vitro culture systems.MethodsRat models of ischemia reperfusion and myocardial infarction were developed using male, Sprague–Dawley rats. Cardiomyocyte and endothelial cell cultures were also established. Therapeutic effects of PB-EPCs were examined in vivo and in vitro in both models. Rats underwent either cardiac ischemia-reperfusion (n = 40) or infarction (n = 56) surgeries and were transplanted with genetically modified EPCs. Treatment efficacy in the ischemia-reperfusion group was measured by infarct size, myocardial contraction velocity, and myeloperoxidase activity after transplantation. Cardiomyocyte survival and endothelial cell apoptosis were investigated in vitro. Vascular growth-associated protein expression and cardiac function were evaluated in the myocardial infarction group by western blot and echocardiography, respectively.ResultsInfarct size and myeloperoxidase activity were significantly decreased in the ischemia-reperfusion group, whereas myocardial contractility was significantly increased in the EPC and Tβ4 groups compared with that in the control group. In contrast, no differences were found between EPC + shRNA Tβ4 and control groups. Rates of cardiomyocyte survival and endothelial cell apoptosis were significantly higher and lower, respectively, in the EPC and Tβ4 groups than in the control group, whereas no differences were found between the EPC + shRNA Tβ4 and control group. Four weeks after myocardial infarction, cardiac function was significantly better in the EPC group than in the control group. Expressions of PDGF, VEGF, and Flk-1 were significantly higher in EPC group than in control group.ConclusionsStudy findings suggest that PB-EPCs are able to protect cardiomyocytes from ischemia-reperfusion or infarction-induced damage via a Tβ4-mediated mechanism. EPCs may also provide protection through increased expression of proteins involved in mediating vascular growth. Autologous peripheral-blood-derived EPCs are readily available for efficient therapeutic use without the concerns of graft rejection.

Glucose-induced increase in circulating progenitor cells is blunted in polycystic amenorrhoeic subjects

Glucose-induced kinetics of bone marrow-derived stem cells in healthy females is presently unknown. The objectives of this study were to determine whether circulating levels of CD133(+), CD34(+) and CD133(+)CD34(+) cells increase in response to glucose load in healthy females and whether the kinetics is altered in amenorrhoeic women. The other objective of the work was to compare the endothelial differentiation potential of peripheral blood-derived endothelial progenitor cells (EPCs) from healthy versus amenorrhoeic women. In this case-control study, 44 amenorrhoeic subjects and 36 age-matched females with no menstrual disturbance were recruited at Apollo Hospitals, a Tertiary health care center in Chennai, India. Circulating bone marrow-derived stem cells were measured by two color direct flow cytometry. Cultured progenitor cells were characterized at Day 7 and 14 for expression of endothelial markers and production of nitric oxide (NO) via immunofluoroscence. The amenorrhoeic subjects were insulin resistant with homeostatic model of assessment of insulin resistance values of 3.33 ± 0.3 versus 1.75 ± 0.148 observed for controls (P< 0.0001). Among the amenorrhoeic subjects, 38 subjects had polycystic ovaries with no signs of hyperandrogenism. Fasting levels of CD133(+), CD34(+) and CD133(+)CD34(+) cells were reduced in amenorrhoeic subjects (P< 0.001). There was a 1.5 to 2-fold increase in the circulating levels of these cells in response to 75 g oral glucose challenge at 1 and 2 h post-load conditions in controls, which was significantly blunted for CD133(+) (P< 0.001) and CD133(+)CD34(+) (P< 0.001) cells in amenorrhoeic subjects. A positive correlation was observed between estrogen and fasting CD133(+) (r= 0.205, P= 0.070), CD34(+) (r= 0.249, P= 0.027) and CD133(+)CD34(+) (r= 0.217, P= 0.055) cell counts. Additionally, fasting counts for CD34(+) and CD133(+)CD34(+) cells positively correlated with FSH and inversely correlated with LH and C-peptide in the polycystic group. Cultured cells from polycystic subjects exhibited reduced adherence to fibronectin and expressed lower levels of endothelial nitric-oxide synthase and NO. Oral glucose-induced increase in circulating numbers of CD133(+) and CD133(+)CD34(+) cells and endothelial differentiation potential of peripheral blood-derived EPCs is attenuated in insulin resistant amenorrhoeic subjects.

CD16 antigen is a positive marker of peripheral blood-derived early endothelial progenitor cells

CD16 antigen is a positive marker of peripheral blood-derived early endothelial progenitor cells

In vivo implantation of a functional tissue engineered stentless pulmonary valve using bone-marrow-derived mesenchymal stem cells and circulating endothelial progenitor cells

Purpose: We investigated the functional potential of poly-4-hydroxybutyrate (P4HB) scaffolds by determining the most suitable thickness and ratio of co-cultured progenitor cells for construction of pulmonary leaflets and annular sewing ring in tissue engineered (TE) stentless PV. Methods: Melt-blown fibronectin (FN)-coated P4HB scaffolds of varying thickness were seeded with different percentages of characterized ovine bone marrow-derived mesenchymal stem cells (MSC) and peripheral blood-derived endothelial progenitor cells (EPC) for 21 days in a laminar flow system. Results: HE α-SMA+ cells were found both on the surface and in the interstitium evidenced by IHC. Immunoblotting revealed increased expression of α-SMA+. Hence, autologous TE stentless PV using 220µM for PV leaflet covered with 100µM for annular sewing ring was successfully placed in PV position. The neo-tissue integrity allowed secure anastomosis with adequate tensile strength. Echocardiography demonstrated normal biventricular function, and adequate leaflet coaptation with trivial central regurgitation. Conclusion: This demonstrates the successful creation of an anatomically functional, autologous TE stentless PV using sequentially seeded progenitor cell sources. This suggest the importance of scaffold thickness and ratio of seeded cells in the suturability of TE stentless PV.