Exercício Físico Melhora as Funções das Células Progenitoras Endoteliais em Pacientes com Síndrome Metabólica / Exercise Training Improves Functions of Endothelial Progenitor Cells in Patients with Metabolic Syndrome

Resumo Fundamento As células progenitoras endoteliais (CPEs) desempenham um papel importante na manutenção da função endotelial. A síndrome metabólica (SM) está associada à disfunção das CPEs. Embora o exercício físico tenha um impacto benéfico na atividade das CPEs, seu mecanismo ainda não está completamente esclarecido. Objetivo O objetivo deste estudo é investigar os efeitos do exercício físico nas funções das CPEs e os mecanismos subjacentes em pacientes com SM. Métodos Os voluntários com SM foram divididos em grupo exercício (n=15) e grupo controle (n=15). Antes e após 8 semanas de treinamento físico, as CPEs foram isoladas do sangue periférico. Foram feitos o ensaio de unidades formadoras de colônias (UFC), o ensaio de formação de tubos, a expressão proteica do óxido nítrico sintase endotelial (eNOS), da fosfatidilinositol-3-quinase (PI3-K) e da proteína quinase B (AKT). Considerou-se um valor de probabilidade <0,05 para indicar significância estatística. Resultados Após 8 semanas, o número de UFCs aumentou significativamente no grupo exercício em comparação com o grupo controle (p<0,05). Além disso, observamos uma diminuição significativa do modelo de avaliação da homeostase da resistência à insulina (HOMA-IR), endotelina-1, proteína C reativa de alta sensibilidade e dos níveis de homocisteína no grupo exercício. A intervenção com exercícios também pode aumentar a capacidade de formação de tubos de CPEs e aumentar o nível de fosforilação de eNOS, PI3-K e AKT. Conclusão O exercício físico aprimorou as funções das CPEs. O mecanismo pode estar relacionado ao exercício, ativando a via PI3-K/AKT/eNOS.

Abstract Background Endothelial progenitor cells (EPCs) play an important role in maintaining endothelial function. Metabolic syndrome (MetS) is associated with EPC dysfunction. Although physical exercise has a beneficial impact on EPC activity, its mechanism is not completely clear yet. Objective The purpose of this study is to investigate the effects of physical exercise on the functions of EPCs and the underlying mechanisms in patients with MetS. Methods Volunteers with MetS were divided into exercise group (n=15) and control group (n=15). Before and after 8 weeks exercise training, EPCs were isolated from peripheral blood. Colony forming unit (CFU) assay, tube-formation assay, the protein expression of endothelial nitric oxide synthase (eNOS), phosphatidylinositol-3-kinase (PI3-K) and protein kinase B (AKT) were determined. A probability value <0.05 was considered to indicate statistical significance. Results After 8 weeks, the number of CFUs was significantly increased in the exercise group compared to the control group (p<0.05). In addition, we observed a significant decrease of homeostasis model assessment for insulin resistance (HOMA-IR), endothelin-1, high-sensitive C-reactive protein, and homocysteine levels in the exercise group. Exercise intervention could also enhance tube-formation capacity of EPCs and increase phosphorylation level of eNOS, PI3-K and AKT. Conclusion Physical exercise enhanced the functions of EPCs. The mechanism may be related to exercise, activating the PI3-K/AKT/eNOS pathway.

Endothelial progenitor cells in the peripheral blood of patients with moyamoya disease labeled with superparamagnetic iron oxide in vitro for MRI detection

Moyamoya disease (MMD) is currently thought to involve endothelial progenitor cells (EPCs). We investigated whether superparamagnetic iron oxide (SPIO) can be used to label EPCs. Mononuclear cells from 10 moyamoya disease patients were isolated, and cluster of differentiation 133 (CD133) positive cells sorted by magnetic-activated cell sorting were cultured in vitro. The positive rates of CD133, vascular endothelial growth factor receptor (VEGFR)-2, and cluster of differentiation 34 (CD34) were detected by flow cytometry. The cells were co-cultured with fluorescence labeled Dil-acetylated-low-density lipoprotein (Dil-ac-LDL) and Ulex europaeus agglutinin-1 (UEA-1) to observe the endocytosis of Dil-ac-LDL and binding to UEA-1. Prussian blue staining and transmission electron microscopy were used to observe the endocytosis of different SPIO concentrations in EPCs, and CCK-8 was used to detect proliferation of cells transfected with different concentrations of SPIO. T2 weighted imaging (T2WI) signals from magnetic resonance imaging after SPIO endocytosis were compared. Positive rates of CD133, VEGFR-2, and CD34 on sorted mononuclear cells were 68.2±3.8, 57.5±4.2, and 36.8±6.5%, respectively. The double-positive expression rate of CD34 and VEGFR-2 was 19.6±4.7%, and 83.1±10.4% of cells, which showed the uptake of Dil-ac-LDL and binding with UEA-1. The labeling efficiencies of SPIO at concentrations of 25 and 50 μg/mL were higher than for 12.5 μg/mL. The proliferation of cells was not influenced by SPIO concentrations of 12.5 and 25 μg/mL. After labeling, the T2WI of EPCs was reduced. The concentration of 25 μg/mL SPIO had high labeling efficiency detected by magnetic resonance imaging (MRI) without decreased EPCs viability.

Effects of antihyperglycemics on endothelial progenitor cells / 浙江大学学报·医学版

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.

Effects of Combined Infusion of Mesenchymal Stem Cells and Endothelial Progenitor Cells on Lung Injury after Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

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.

High levels of endothelial progenitor cells and circulating endothelial cells in patients with Behçet's disease and their relationship to disease activity

Abstract: Background: Behçet's disease is a multisystemic vasculitis, associated with vascular endothelial dysfunction. Currently, the prognosis is unpredictable, because there is still no valid laboratory marker indicating the disease activity in Behçet's disease. Endothelial progenitor cells and circulating endothelial cells are newly introduced hematological markers which are presumed to take part in the pathogenesis of vasculitis. Objectives: To evaluate the levels of endothelial progenitor cells and subtypes and circulating endothelial cells in patients with Behçet's disease and to describe their relationship with the disease activity. Methods: A total of 45 patients with Behçet's disease and 28 healthy controls were included in the study. Endothelial progenitor cells (CD34+CD133+KDR+ as early endothelial progenitor cells and CD34+KDR+ as late endothelial progenitor cells), and circulating endothelial cells (CD34+CD133+) were measured by flow cytometry. Results: The mean plasma level of endothelial progenitor cells and circulating endothelial cells, vascular endothelial growth factor, matrix metalloproteinase-9, C-reactive protein, and erythrocyte sedimentation rate were significantly higher in patients with Behçet's disease. All of these parameters except circulating endothelial cells were also found to be higher in patients with active disease than in patients with inactive disease. Early endothelial progenitor cells showed significant correlations with C-reactive protein and circulating endothelial cells. Study Limitations: The cross-sectional nature of the study and patient characteristics such as being under treatment, which can affect endothelial progenitor cells numbers. Conclusion: The increase in endothelial progenitor cells may play an essential role in the repair of endothelial injury in Behçet's disease, especially in the active period of the disease. Thus, endothelial progenitor cells can indicate the disease activity. In addition, endothelial progenitor cells and circulating endothelial cells can be used as endothelial repair and injury markers for Behçet's disease, respectively.

Poly(trimethylene carbonate-co-L-lactide) electrospun scaffolds for use as vascular grafts

Currently, there is great clinical need for suitable synthetic grafts that can be used in vascular diseases. Synthetic grafts have been successfully used in medium and large arteries, however, their use in small diameter vessels is limited and presents a high failure rate. In this context, the aim of this study was to develop tissue engineering scaffolds, using poly(trimethylene carbonate-co-L-lactide) (PTMCLLA), for application as small diameter vascular grafts. For this, copolymers with varying trimethylene carbonate/lactide ratios - 20/80, 30/70, and 40/60 - were submitted to electrospinning and the resulting scaffolds were evaluated in terms of their physicochemical and biological properties. The scaffolds produced with PTMCLLA 20/80, 30/70, and 40/60 showed smooth fibers with an average diameter of 771±273, 606±242, and 697±232 nm, respectively. When the degradation ratio was evaluated, the three scaffold groups had a similar molecular weight (Mw) on the final day of analysis. PTMCLLA 30/70 and 40/60 scaffolds exhibited greater flexibility than the PTMCLLA 20/80. However, the PTMCLLA 40/60 scaffolds showed a large wrinkling and their biological properties were not evaluated. The PTMCLLA 30/70 scaffolds supported the adhesion and growth of mesenchymal stem cells (MSCs), endothelial progenitor cells, and smooth muscle cells (SMCs). In addition, they provided a spreading of MSCs and SMCs. Given the results, the electrospun scaffolds produced with PTMCLLA 30/70 copolymer can be considered promising candidates for future applications in vascular tissue engineering.

Changes in corneal endothelial cells following MSICS versus conventional ecce in a tertiary eye Hospital in north western Nigeria

Background: This study was undertaken to compare the effect of two surgical techniques of cataract extraction on corneal endothelial cell density in eyes of Nigerian adults with uncomplicated age-related cataract with the view to improving surgical visual function and quality of life. Materials and Methods: It was a prospective randomized non blinded hospital based interventional study. Two hundred and seventy-seven (277) eyes of 269 eligible patients with cataract were randomized to either manual small incision cataract surgery (MSICS) or conventional extracapsular cataract extraction (ECCE). The endothelial cell density (ECD), Coefficient of variation (CV), and Hexagonality (%) were measured pre-operatively, at one, four and twelve weeks post-operatively with a non-contact specular microscope (CSO SP 02). Statistical analysis ­ Data obtained were entered into microsoft Excel and analyzed using SPSS version 16 software.Result: Of the 277 eyes studied, 263 (94.9%) were analysed. The mean age of patients for MSICS and ECCE was 64.03 (SD + 11.2, range 40 ­ 95 years) and 62.69 (SD +10.48, range 42 ­ 94 years) respectively. The Male to female ratio was 1.9:1, in the two study groups. Pre-operatively, corneal parameters (mean ECD,CV and hexagonal cells) were similar between the two surgery groups. Postoperatively cataract surgery induced a mean endothelial cell density loss of 5.31% at one week, 7.28% at 4 weeks and 7.06% at 12 weeks in the study population. There was no statistically significant difference in the mean endothelial cell density loss between MSICS and ECCE groups. Conclusion: Both MSICS and ECCE induced fairly equal moderate and reversible degree of endothelial cell density loss in adults with uncomplicated age related cataract

Isolation, Culture and Biological Characteristics of Endothelial Progenitor Cells from Cryopreserved Umbilical Cord Blood / 中国实验血液学杂志

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.

Adult Stem Cells: Beyond Regenerative Tool, More as a Bio-Marker in Obesity and Diabetes

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.

Effects of ATP on expression of inflammatory factors in endothelial progenitor cells induced by LPS and the mechanisms / 中南大学学报(医学版)

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.

Effects of endothelial progenitor cells on proliferation and biological function of hepatic stellate cells under shear stress / 中国应用生理学杂志

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.

Hypoxia-dependent mitochondrial fission regulates endothelial progenitor cell migration, invasion, and tube formation

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.

Correlation between NADPH oxidase-mediated oxidative stress and dysfunction of endothelial progenitor cell in hyperlipidemic patients

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.

Immunohistomorphology of pancreatic islet microvasculature and the immunophenotypic analysis of CEPC in adult diabetic rats / Inmunohistomorfología de microvasculatura de islotes pancreatic y el análisis inmunofenotípico de CEPC en ratas diabéticas adultas

SUMMARY: Hyperglycaemia is one of the main causes for the endothelial cell (EC) damage in diabetic patients. Even though circulating endothelial progenitor cells (CEPC) could be used as a prognosis for microvascular complications, there is very little information on the islet microvasculature. We analysed by immunohistochemistry and by flow cytometric immunophenotyping, the expression of CD34 on EC and the expressions of CD31, CD34, CD45 and CD133 on CEPC in Streptozotocin (STZ)-induced diabetic rats. Peripheral blood and tissue specimens were obtained from rats of different treatment regimens: STZ treatment, control saline (NS) and sodium citrate (CB) treatments. Blood cells were exposed to flow cytometric immunophenotyping for CD133, CD31, CD34, CD45 and CD133. While tissues from the pancreas, liver and kidney were routinely processed and stained immunohistochemically for CD34. There was a tendency of an increased in CD45-/CD133+/CD31+/CD34+ cells (0.04 ± 0.11 %) in diabetic rats compared to the controls (CB: 0.03 ± 0.04 %; Saline: 0.01 ± 0.03 %). But there was no significant statistical difference between them. The expression pattern of CD34 on the EC in the organs' vascular beds including arterioles, venules, capillaries and sinusoids was extremely heterogeneous across and within treatment regimens. The ECs in the sinusoids of the liver presented similar CD34 expression patterns across different treatment regimens, while the expression of CD34 on the ECs of sinusoidal capillaries in the pancreas vary with the treatment regimen. We conclude that the degree of endothelial cell damage is not uniform across organs' vascular beds in the rat, contrary to mice and humans. Furthermore, the sinusoids in the pancreas and the kidney may have the same degree of endothelial damage when exposed to the same deleterious causes.

RESUMEN: La hiperglucemia es una de las principales causas del daño de las células endoteliales (EC) en pacientes diabéticos. A pesar de que las células progenitoras endoteliales circulantes (CEPC) podrían utilizarse como pronóstico de las complicaciones microvasculares, hay muy poca información sobre la microvasculatura de los islotes. Se analizaron por inmunohistoquímica y por inmunofenotipificación citométrica de flujo, la expresión de CD34 en EC y las expresiones de CD31, CD34, CD45 y CD133 en CEPC en ratas diabéticas inducidas por estreptozotocina (STZ). Se obtuvieron muestras de sangre y tejidos periféricos a partir de ratas de diferentes regímenes de tratamiento: tratamiento con STZ, solución salina control (NS) y citrato de sodio (CB). Las células sanguíneas fueron expuestas a inmunofenotipado por citometría de flujo para CD133, CD31, CD34, CD45 y CD133. Mientras que los tejidos del páncreas, el hígado y el riñón fueron rutinariamente procesados y teñidos inmunohistoquímicamente para CD34. Se observó una tendencia a un aumento en las células CD45- / CD133 + / CD31 + / CD34 + (0,04 ± 0,11 %) en ratas diabéticas en comparación con los controles (CB: 0,03 ± 0,04 %; Salino: 0,01 ± 0,03 %). Pero no hubo diferencias estadísticamente significativas entre ellos. El patrón de expresión de CD34 en la EC en los lechos vasculares de los órganos incluyendo arteriolas, vénulas, capilares y sinusoides fue extremadamente heterogéneo a través de y dentro de los regímenes de tratamiento. Las EC en los sinusoides del hígado presentaron patrones de expresión de CD34 similares a través de diferentes regímenes de tratamiento, mientras que la expresión de CD34 en las CE de capilares sinusoidales en el páncreas varía con el régimen de tratamiento. Concluimos que el grado de daño de las células endoteliales no es uniforme en los lechos vasculares de los órganos en la rata, en comparación de los ratones y los seres humanos. Además, los sinusoides en el páncreas y el riñón pueden tener el mismo grado de daño endotelial cuando se exponen a las mismas causas deletéreas.

Effects of Chronic Exercise on Endothelial Progenitor Cells and Microparticles in Professional Runners / Efeitos de Exercício Crônico Sobre Células Progenitoras Endoteliais e Micropartículas em Corredores Profissionais

Abstract Background: The effects of chronic exposure to exercise training on vascular biomarkers have been poorly explored. Objective: Our study aimed to compare the amounts of endothelial progenitor cells (EPCs), and endothelial (EMP) and platelet (PMP) microparticles between professional runners and healthy controls. Methods: Twenty-five half-marathon runners and 24 age- and gender-matched healthy controls were included in the study. EPCs (CD34+/KDR+, CD133+/KDR+, and CD34+/CD133+), EMP (CD51+) and PMP (CD42+/CD31+) were quantified by flow-cytometry. All blood samples were obtained after 12 h of fasting and the athletes were encouraged to perform their routine exercises on the day before. Results: As compared with controls, the CD34+/KDR+ EPCs (p=0.038) and CD133+/KDR+ EPCs (p=0.018) were increased, whereas CD34+/CD133+ EPCs were not different (p=0.51) in athletes. In addition, there was no difference in MPs levels between the groups. Conclusion: Chronic exposure to exercise in professional runners was associated with higher percentage of EPCs. Taking into account the similar number of MPs in athletes and controls, the study suggests a favorable effect of exercise on these vascular biomarkers.

Resumo Fundamento: Os efeitos da exposição crônica ao exercício sobre biomarcadores vasculares foram pouco estudados. Objetivo: Nosso estudo teve como objetivo comparar as quantidades de células progenitoras endoteliais (CPEs), e de micropartículas endoteliais (MPEs) e plequetárias (MPPs) de corredores profissionais com controles sadios. Métodos: Vinte e cinco corredores de meia maratona e 24 controles pareados quanto à idade e ao sexo foram incluídos no estudo. CPEs (CD34+/KDR+, CD133+/KDR+ e CD34+/CD133+), MPE (CD51+) e MPPs (CD42+/CD31+) foram quantificadas por citometria de fluxo. Todas as amostras de sangue foram obtidas após 12 horas de jejum, e os atletas foram incentivados a realizar seus exercícios de rotina no dia anterior à coleta. Resultados: Em comparação aos controles, CPEs CD34+/KDR+ (p=0,038) e CD133+/KDR+ (p=0,018) estavam aumentados, e CPEs CD34+/CD133+ não foram diferentes (p=0,51) nos atletas. As concentrações de MP não diferiram entre os grupos. Conclusão: A exposição crônica ao exercício em corredores profissionais associou-se a uma maior porcentagem de CPEs. Considerando o número similar de MPs entre atletas e controles, o estudo sugere um efeito favorável do exercício sobre esses biomarcadores vasculares.

Endothelial Progenitor Cells Correlated with Oxidative Stress after Mild Traumatic Brain Injury

PURPOSE: Endothelial progenitor cells (EPCs) play a key role in tissue repair and regeneration. Previous studies have shown that infusion of human umbilical cord blood-derived endothelial colony-forming cells improves outcomes in mice subjected to experimental traumatic brain injury (TBI). However, the efficiency of cell transplantation is not satisfactory. Oxidative stress plays a significant role in the survival of transplanted cells following ischemic reperfusion injury. This observational clinical study investigated the correlation between the number of circulating EPCs and plasma levels of superoxide dismutase (SOD) and malonyldialdehyde (MDA). MATERIALS AND METHODS: Peripheral blood samples were collected from 20 patients with mild TBI at day-1, day-2, day-3, day-4, and day-7 post TBI. The number of circulating EPCs and the plasma levels of SOD and MDA were measured. RESULTS: The average of circulating EPCs in TBI patients decreased initially, but increased thereafter, compared with healthy controls. Plasma levels of SOD in TBI patients were significantly lower than those in healthy controls at day-4 post-TBI. MDA levels showed no difference between the two groups. Furthermore, when assessed on day-7 post-TBI, the circulating EPC number were correlated with the plasma levels of SOD and MDA. CONCLUSION: These results suggest that the number of circulating EPCs is weakly to moderately correlated with plasma levels of SOD and MDA at day-7 post-TBI, which may offer a novel antioxidant strategy for EPCs transplantation after TBI.

Engineered M13 Nanofiber Accelerates Ischemic Neovascularization by Enhancing Endothelial Progenitor Cells

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.

Endothelial Progenitor Cells' Classification and Application in Neurological Diseases

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.

Surface Coating of Polytetrafluoroethylene with Extracellular Matrix and Anti-CD34 Antibodies Facilitates Endothelialization and Inhibits Platelet Adhesion Under Sheer Stress

Expanded polytetrafluoroethylene (ePTFE) polymers do not support endothelialization because of nonconductive characteristics towards cellular attachment. Inner surface modification of the grafts can improve endothelialization and increase the long-term patency rate of the ePTFE vascular grafts. Here we reported a method of inner-surface modification of ePTFE vascular graft with extracellular matrix (ECM) and CD34 monoclonal antibodies (CD34 mAb) to stimulate the adhesion and proliferation of circulating endothelial progenitor cells on ePTFE graft to enhance graft endothelialization. The inner surface of ECM-coated ePTFE grafts were linked with CD34 mAb in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) solution and the physicochemical properties, surface morphology, biocompatibility, and hemocompatibility of the grafts were studied. The hydrophilicity of CD34 mAb-coated graft inner surface was significantly improved. Fourier transform infrared spectroscopy analysis confirmed ECM and CD34 mAb cross-linking in the ePTFE vascular grafts with our method. Scanning electron microscopy analysis showed protein layer covering uniformly on the inner surface of the modified grafts. The cell-counting kit-8 (CCK-8) assay confirmed that the modified graft has no obvious cytotoxicity. The modified graft showed a low hemolytic rate (0.9%) in the direct contact hemolysis test, suggesting the modification improved hemocompatibility of biopolymers. The modification also decreased adhesion of platelets, while significantly increased the adhesion of endothelial cells on the grafts. We conclude that our method enables ePTFE polymers modification with ECM and CD34 mAb, facilitates endothelialization, and inhibits platelet adhesion on the grafts, thus may increase the long-term patency rate of the prosthetic bypass grafts.