Mobilization Of Endothelial Progenitor Cells Research Articles

Tibial transverse transport induces mobilization of endothelial progenitor cells to accelerate angiogenesis and ulcer wound healing through the VEGFA/CXCL12 pathway

BackgroundTibial transverse transport (TTT) can promote the healing of chronic foot ulcers, but the specific cellular and molecular mechanisms by which TTT promotes wound healing remain unclear. MethodsNew Zealand White rabbits were selected to induce foot ulcers by implanting a magnetic sheet for circulation compression. The treatment included unilateral TTT surgery and bilateral TTT surgery. Observation of tissue neovascularization structure by HE staining and CD31 immunofluorescence detection. Collagen fiber formation was detected through Masson staining. The mobilization of endothelial progenitor cell (EPCs) were analyzed by VEGFR2 immunofluorescence detection and flow cytometry detection of the number of VEGFR2/Tie-2-positive cells in peripheral blood. ELISA and qPCR assay were performed to detect VEGFA and CXCL12 levels. ResultsThe complete healing time of ulcer surfaces in sham, unilateral and bilateral TTT groups was about 22 days, 17 days and 13 days, respectively. TTT treatment significantly increased the deposition of granulation tissue and epithelialization of wounds. It also led to an increase in collagen fiber content and the level of the microvascular marker CD31. Furthermore, TTT treatment upregulated the levels of VEGFA and CXCL12 in peripheral blood and wound tissues, as well as increased the expression of VEGFR2 in wound tissues and the proportion of VEGFR2/Tie-2 in peripheral blood. Moreover, these effects of TTT treatment in the bilateral group was more significant than that in the unilateral group. ConclusionsTTT may facilitate wound fibroblasts to release VEGFA and CXCL12, causing EPC mobilization, thus promoting angiogenesis and ulcer wound healing.

The Role of Angiogenesis Mediators in the Mobilization of Early and Late Endothelial Progenitor Cells from the Bone Marrow in Coronary Heart Disease

Background. A severe form of coronary heart disease (CHD) is ischemic cardiomyopathy (ICMP), the pathogenesis of which has not been fully studied. Disturbances in the mobilization of endothelial progenitor cells (EPC) due to an imbalance of angiogenesis mediators may exacerbate ischemia in ICMP. The aim — to establish the peculiarities of changes in the balance of early and late EPС and subpopulations of VEGFR2+ cells in the blood and bone marrow in relation to the content of angiogenesis mediators and the number of desquamated endothelial cells (DEK) in the blood of patients with CHD, suffering and not suffering from ICMP. Methods. A single-stage, clinical, controlled (case-control) study was conducted from March 2019 to June 2022. 52 patients with CHD who had a history of myocardial infarction were examined: 30 people suffering from ICMP and 22 people not suffering from ICMP, as well as 15 healthy donors. The content of VEGFR2+, VEGFR2+CD34+CD14+ (early EPC), VEGFR2+CD34+CD14– (late EPC), VEGFR2+CD34–CD14+, VEGFR2+CD34–CD14– cells in patients with CHD in the blood (before surgery) and bone marrow (sampling was performed at the beginning of coronary bypass) and in healthy individuals in the blood, as well as (in both groups) the content of CD45–CD146+ DEC in the blood was determined by flow cytometry. The concentration of SDF-1, VEGF-A, MCP-1, GM-CSF, G-CSF in blood plasma was measured by multiplex immunofluorescence analysis. Results. The development of CHD without cardiomyopathy was accompanied by an increase in the content of VEGFR2+CD34+CD14+ and VEGFR2+ cells (0.74 [0.46; 1.23]% and 10.00 [8.20; 11.60]%, respectively, versus 0.19 [0.13; 0.32]%, p 0.001 and 5.40 [4.30; 6.50]%, p = 0.005) and concentrations of SDF-1, MCP-1, GM-CSF (respectively 60.00 [50.00; 81.00] pg/ml; 223.0 [180.0; 297.0] pg/ml; 2.10 [1.45; 3.40] pg/ml versus 30.00 [5.00; 45.00] pg/ml, p = 0.041; 175.1 [140.0; 204.0] pg/ml, p = 0.046; 0.96 [0.46; 1.41] pg/ml, p = 0.038) in the blood relative to the norm. No such changes were observed in patients with ICMP. Regardless of the presence of ICMP, the content of VEGFR2+CD34+CD14–, VEGFR2+CD34–CD14+, VEGFR2+CD34–CD14– cells, VEGF-A, G-CSF in the blood of patients with CHD varied within physiological values, and the number of DEC exceeded the norm (7.26 [5.43; 17.94]×105/l, p = 0.039). The number of VEGFR2+ cells and their immunophenotypes in the bone marrow of patients with ICMP did not differ from the parameters in patients with CHD without cardiomyopathy. Prolonged bleeding from the venopuncture area was registered in one CHD patient without cardiomyopathy. Conclusion. The development of ICMP is associated with the absence of a compensatory response to atherogenesis in the form of increased mobilization of early EPC from the bone marrow due to the absence of a reaction associated with hyperproduction of SDF-1, MCP-1, GM-CSF, which is characteristic of CHD without cardiomyopathy. The content of EPС, VEGFR2+CD34–CD14+ and VEGFR2+CD34–CD14– cells, VEGF-A and G-CSF in the blood in СHD corresponds to physiological values, regardless of the presence of ICMP. The generation of EPC in the bone marrow in ICMP is not impaired.

Intravenous iron administration in patients with heart failure alters endothelial homeostasis with early release of endothelial microvesicles and subsequent mobilization of endothelial progenitor cell

Abstract Background Intravenous iron supplementation is an established therapy for patients with heart failure (HF) with reduced ejection fraction (LV-EF<50%) and iron deficiency, resulting in reduced risk of HF hospitalization. Since iron may induce oxidative stress, inflammation and apoptosis in endothelial cells, concerns persist regarding potential adverse vascular effects of iron therapy. To evaluate endothelial health following ferric carboxymaltose (FCM) administration, we assessed the profile of circulating endothelial microvesicles (EMVs) and endothelial progenitor cells (EPCs) in a cohort of 23 HF patients using flow cytometry. Results Compared to healthy control subjects (HC; n=15), baseline levels of CD31+/CD41- EMVs were significantly higher and EMVs featured a more apoptotic phenotype in HF patients. Following administration of 1000mg FCM, EMV levels showed an early but transient increase (Fig. 1) and displayed an altered phenotype profile with dominant augmentation of EMVs expressing the inducible markers CD62E and CD54, indicating endothelial activation and injury. Levels of circulating vasoregenerative CD45lowCD34+KDR+ EPCs were lower in HF patients and FCM application resulted in an early decrease of EPCs followed by substantial mobilization into the circulation after one week (Fig. 2). Levels of EMVs and EPCs returned to baseline values within two and four weeks, respectively. Compared to HF patients with preserved renal function, the EMV/EPC ratio was higher in HF patients whereas EPC mobilization was diminished with additional chronic kidney disease, suggesting impaired vascular repair capacity. In vitro experiments with cultured endothelial cells revealed that FCM at therapeutic concentrations dose-dependently promotes endothelial apoptosis, increases expression of adhesion molecules and CXCL12, and triggers the generation of EMVs. Conclusion Intravenous iron supplementation with FCM in HF patients provokes a biphasic response with early release of CD62E+ and CD54+ enriched EMVs and subsequent mobilization of EPCs, suggesting temporary aggravation of endothelial dysfunction upon FCM supplementation and consecutive engagement of a vascular defense program.

Abstract 17537: Myocardial Dysfunction is Associated With Impaired Angiogenesis in Patients With Heart Failure With Preserved Ejection Fraction

Background: Recent evidence suggests that myocardial microvascular damage may represent a key parameter in the pathogenesis of heart failure with preserved ejection fraction (HFpEF). Aim: We sought to investigate a potential correlation between parameters of angiogenesis and myocardial dysfunction in HFpEF patients. Methods: We enrolled 30 consecutive HFpEF patients with NYHA class III, left ventricular ejection fraction (LVEF) >50%, E/e' >15, and NT-proBNP >300 pg/ml. In all patients endothelial progenitor cells (EPCs) were mobilized by granulocyte-colony stimulating factor (G-CSF; 10 mcg/kg, 5 days) and collected via apheresis. Before EPC mobilisation we performed echocardiography and measured plasma levels of biomarkers of angiogenesis. All patients underwent electroanatomical mapping for the measurement of myocardial viability; preserved viability was defined as mean unipolar voltage> 8.3 mV. Results: Myocardial viability was preserved in 11 patients (37%; Group A) and decreased in 19 patients (63%; Group B). The groups did not differ in age (63±10 years in Group A vs. 61±8 years in Group B, P=0.78), gender (male: 73% vs. 79%, P=0.70), serum creatinine (1.07±0.34 mg/dL vs. 1.04±0.40 mg/dL, P=0.43), or LVEF (60±7% vs. 57±4%, P=0.32). In Group B we found higher levels of NT-proBNP (2370±1020 pg/mL vs. 920±455 pg/mL in Group A, P=0.04) and E/e’ (23.2±3.1 vs. 17.4±1.8 pg/ in Group A, P=0.02). After G-CSF stimulation, we found significantly lower numbers of EPCs in Group B (53±42 x10 6 cells/L) than in Group A (102±52 x10 6 cells/L, P=0.001). Similarly, apheresis yielded lower numbers of EPCs in Group B (85±82 x10 6 cells vs. 200±93 x10 6 cells in Group A, P=0.003). When compared to Group A, patients in Group B displayed lower levels of pro-angiogenic biomarkers (agiopoietin-1: 7.4±2.8 ng/mL vs. 12.4±5.1 ng/mL, P=0.02; vascular endothelial growth factor: 27.5±20.1 pg/mL vs. 51.6±24.2 pg/mL, P=0.01), and higher levels of anti-angiogenic biomarkers (endostatin: 56.5±19.1 ng/mL vs. 33.2±14.3 ng/mL, P=0.01; thrombospondin-2: 16.4±4.3 ng/mL vs. 9.2±5.0 ng/mL, P=0.03). Conclusion: In patients with HFpEF, myocardial dysfunction appears to correlate with reduced mobilisation of endothelial progenitor cells and impaired angiogenesis.

The Effects of a Cardiac Rehabilitation Program on Endothelial Progenitor Cells and Inflammatory Profile in Patients with Chronic Heart Failure of Different Severity.

Endothelial dysfunction and inflammation are common pathophysiological characteristics of chronic heart failure (CHF). Endothelial progenitor cells (EPCs) are recognized as useful markers of vascular damage and endothelial repair. The aim of this study was to investigate the effects of a cardiac rehabilitation program on EPCs and inflammatory profile in CHF patients of different severity. Forty-four patients with stable CHF underwent a 36-session cardiac rehabilitation program. They were separated into two different subgroups each time, according to the median peak VO2, predicted peak VO2, VE/VCO2 slope, and ejection fraction. EPCs, C-reactive protein (CRP), interleukin 6 (IL-6), interleukin 10 (IL-10), and vascular endothelial growth factor (VEGF) were measured. Flow cytometry was used for the quantification of EPCs. Mobilization of EPCs increased and the inflammatory profile improved within each severity group (p < 0.05) after the cardiac rehabilitation program, but there were no statistically significant differences between groups (p > 0.05). A 36-session cardiac rehabilitation program has similar beneficial effects on the mobilization of EPCs and on the inflammatory profile in patients with CHF of different severity.

Granulocyte Colony-Stimulating Factor Improves Endothelial Progenitor Cell-Mediated Neovascularization in Mice with Chronic Kidney Disease.

Patients with chronic kidney disease (CKD) have a higher prevalence of peripheral arterial disease (PAD), and endothelial progenitor cells (EPCs) play a pivotal role. We examined the impact of granulocyte colony-stimulating factor (G-CSF) on EPC function in response to tissue ischemia. Eight-week-old male C57BL/6J male mice were divided into sham operation and subtotal nephrectomy (SNx) groups, received hindlimb ischemic operation after seven weeks, then randomly received G-CSF or PBS intervention for four weeks with weekly follow-ups. SNx mice had significantly reduced limb reperfusion, decreased plasma EPC mobilization, and impaired angiogenesis in ischemic hindlimbs compared to the control group. However, G-CSF increased IL-10 and reversed these adverse changes. Additionally, ischemia-associated protein expressions, including IL-10, phospho-STAT3, VEGF, and phospho-eNOS, were significantly downregulated in the ischemic hindlimbs of SNx mice versus control, but these trends were reversed by G-CSF. Furthermore, in cultured EPCs, G-CSF significantly attenuated the decrease in EPC function initiated by indoxyl sulfate through IL-10. Overall, we discovered that G-CSF can improve EPC angiogenic function through a hypoxia/IL-10 signaling cascade and impede neovascular growth in response to ischemia of SNx mice. Our results highlight G-CSF's potential to restore angiogenesis in CKD patients with PAD via EPC-based methods.

[Relationship between promoting effect of Zuogui Pills on angiogenesis of reproductive organs and mobilization factors GM-CSF, SDF-1, and their receptors of EPCs in early-aging rats].

This study aimed to investigate the relationship between the promoting effect of Zuogui Pills on ovarian and vaginal angiogenesis in early-aging rats and mobilization factors granulocyte-macrophage colony-stimulating factor(GM-CSF), stromal cell-derived factor-1(SDF-1), and their receptors of endothelial progenitor cells(EPCs) and explore the mechanism of Zuogui Pills in improving reproductive hypofunction in early-aging rats. Ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS) was used to analyze the chemical components of the extract of Zuogui Pills. Forty 14-month-old female early-aging rats with estrous cycle disorder were randomly divided into a blank group, a conjugated estrogen group(conjugated estrogen suspension, 65 μg·kg~(-1)), and low-(11 g·kg~(-1)) and high-dose(33 g·kg~(-1)) Zuogui Pills groups, with 10 rats in each group. In addition, 10 4-month-old female rats were assigned to the youth control group. The rats in the blank group and the youth control group were treated with 20 g·kg~(-1) distilled water by gavage, while those in the groups with drug intervention were treated with corresponding drugs by gavage, once a day for 15 days. Enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of SDF-1 and GM-CSF in the mobilization of EPCs in serum. Hematoxylin-eosin(HE) staining was used to observe the changes in the number of ovarian follicles at all levels and corpus luteum, the number of vaginal epithelial layers, the number of vaginal folds, and the blood vessels of ovarian and vaginal tissues in the groups with drug intervention. Western blot was used to detect the expression of ER, GM-CSFR, CXCR4, and CXCR7 proteins in ovarian and vaginal tissues. As revealed by the results, the blank group showed decreased number of corpus luteum, gro-wing follicles at all levels, and blood vessels(P&lt;0.05), decreased thickness of vaginal mucosa, the number of epithelial layers, the number of vaginal folds, and the number of vessels in the lamina propria(P&lt;0.05), reduced content of SDF-1 and GM-CSF in the peripheral blood(P&lt;0.05), and down-regulated levels of ER, CXCR4, CXCR7, and GM-CSFR proteins in ovarian and vaginal tissues(P&lt;0.05). The groups with drug intervention showed increased number of growing follicles at all levels, corpus luteum, and blood vessels(P&lt;0.05), decreased number of atresia follicles(P&lt;0.05), increased thickness of vaginal mucosa, the number of epithelial layers, the number of vaginal mucosal folds, and the number of blood vessels in the lamina propria(P&lt;0.05), increased content of SDF-1 and GM-CSF in the peripheral blood(P&lt;0.05), and up-regulated levels of ER, CXCR4, CXCR7, and GM-CSFR proteins in ovarian and vaginal tissues(P&lt;0.05). This experiment suggests that Zuogui Pills may promote ovarian and vaginal angiogenesis and improve the reproductive function of early-aging rats by up-regulating the levels of mobilization factors SDF-1, GM-CSF, and their receptors of EPCs.

Exploration of the influence of early rehabilitation training on circulating endothelial progenitor cell mobilization in patients with acute ischemic stroke and its related mechanism under a lightweight artificial intelligence algorithm.

This work aimed to explore the application of lightweight artificial intelligence algorithms in magnetic resonance imaging (MRI) image processing of patients with acute ischemic stroke (AIS) to clarify the effect and mechanism of early rehabilitation training on the mobilization of circulating endothelial progenitor cells (EPCs) in AIS. A total of 98 AIS patients undergoing MRI examination were selected as the research objects and were randomly divided into a rehabilitation group (early rehabilitation training, 50 cases) and a routine group (conventional treatment, 48 cases) by random number table method and lottery method. In this work, based on the convolutional neural network (CNN) algorithm, a low-rank decomposition algorithm was introduced to optimize it, and a lightweight MRI image computer intelligent segmentation model (LT-RCNN) was established. The LT-RCNN model was used in the MRI image processing of AIS patients, and the role of the model in AIS image segmentation and lesion localization was analyzed. Furthermore, flow cytometry was used to detect the number of peripheral circulating EPCs and CD34+KDR+ cells in the two groups of patients before and after treatment. The serum levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α), interleukin 10 (IL-10), and stromal cell-derived factor-1α (SDF-1α) content were detected by Enzyme-Linked Immunosorbent Assay (ELISA). In addition, the correlation between each factor and CD34+KDR+ was analyzed by Pearson linear correlation. The diffusion-weighted imaging (DWI) signal of MRI images of AIS patients under the LT-RCNN model was high. The location of the lesion could be accurately detected, and the contour of the lesion could be displayed and segmented, and the segmentation accuracy and sensitivity were significantly better than before optimization. The number of EPCs and CD34+KDR+ cells in the rehabilitation group was increased compared with the control group (p<0.01); the expression levels of VEGF, IL-10, and SDF-1α were higher than those of the control group (p<0.001), and TNF-α content was lower than the control group (p<0.001). The number of CD34+KDR+ cells was positively correlated with VEGF, IL-10, and TNF-α contents (p<0.01). The results showed that the computer-intelligent segmentation model LT-RCNN could accurately locate, and segment AIS lesions and the early rehabilitation training could change the expression level of inflammatory factors and further promote the mobilization of AIS circulation EPCs.

Very short-term tissue coverage of the CD34 antibody-covered sirolimus-eluting stent: an optical coherence tomography study.

It is well known that patients with acute myocardial infarction (AMI) have delayed vessel healing despite accelerated endothelial progenitor cells (EPC) mobilization. The COMBO stent is a unique biodegradable-polymer sirolimus-eluting stent with an anti-CD34 antibody coating which captures EPC and potentially promotes vessel healing. However, there are limited data about strut tissue coverage at the very short-term period after COMBO stent implantation. This was a prospective study to investigate strut tissue coverage within 1month after COMBO stent implantation using optical coherence tomography (OCT). Struts fully covered with tissue were defined as covered, and struts with distance from lumen surface longer than strut plus polymer thickness were defined as malapposed. Mean tissue thickness was measured only in apposed struts. A total of 8173 struts of 33 lesions in 32 patients were analyzed at an average of 19.8 ± 4.6days after COMBO stent implantation. In lesion-level analysis, the rate of covered struts was 89.6 ± 7.2%, the rate of malapposed struts was 0.9 ± 2.0% and mean tissue thickness was 46.8 ± 14.3µm. In comparison between AMI (n = 12) and non-AMI (n = 21) patients, there were no significant differences in the rate of covered struts (88.4 ± 8.4% vs. 90.2 ± 6.6%, p = 0.48) and mean tissue thickness (46.8 ± 13.7µm vs. 46.9 ± 15.0µm, p = 0.98). Multivariable analysis demonstrated that time from implantation to OCT imaging was significantly associated with mean tissue thickness. The COMBO stent had substantial tissue coverage at the very short-term period after implantation even in AMI patients, and follow-up time had an impact on vessel healing.

Intravenous iron supplementation in heart failure patients induces temporary endothelial dysfunction with release of endothelial microvesicles.

Intravenous iron supplementation is an established therapy for patients with heart failure (HF) and concomitant iron deficiency reducing the risk of HF hospitalization. However, concerns persist regarding potential adverse vascular effects, since iron may induce oxidative stress, inflammation, and apoptosis of endothelial cells. To assess endothelial health following ferric carboxymaltose (FCM) administration, we analyzed the profile of circulating endothelial microvesicles (EMVs) and endothelial progenitor cells (EPCs) in a cohort of 23 HF patients using flow cytometry. Compared to healthy subjects, baseline levels of CD31+/CD41- EMVs were higher and EMVs featured a more apoptotic phenotype in HF patients. Following FCM administration, EMV levels showed a rapid but transient increase and displayed an altered phenotype profile with dominant augmentation of EMVs expressing inducible markers CD62E and CD54, indicating endothelial inflammatory activation and injury. Levels of circulating vasoregenerative CD45lowCD34+KDR+ EPCs were lower in HF patients and FCM application resulted in an early decrease of EPCs followed by substantial mobilization into the circulation after one week. Levels of EMVs and EPCs returned to baseline values within two and four weeks, respectively. HF patients with additional chronic kidney disease showed an elevated EMV/EPC ratio and diminished EPC mobilization, suggesting impaired vascular repair capacity. Providing a mechanistic link, in vitro experiments with cultured endothelial cells revealed that FCM dose-dependently promotes endothelial apoptosis, increases expression of adhesion molecules and CXCL12, and triggers generation of EMVs. Intravenous iron supplementation with FCM in HF patients induces a biphasic response with initial increased release of CD62E+ and CD54+ enriched EMVs and subsequent mobilization of EPCs, indicating endothelial dysfunction upon FCM and suggesting consecutive engagement of a defense program aimed to reconstitute vascular health.

Genistein, a Soybean Isoflavone, Promotes Wound Healing by Enhancing Endothelial Progenitor Cell Mobilization in Rats with Hemorrhagic Shock.

Severe trauma and hemorrhaging are often accompanied by delayed cutaneous wound healing. Soybean isoflavone is a natural phytoestrogen that has attracted great attention due to its protective effects against various injuries. Endothelial progenitor cells (EPCs) are precursor cells with directional differentiation characteristics. This study is to determine whether genistein (GEN), an isoflavone in soybean products, benefits wound healing in hemorrhagic shock (HS) rats by promoting EPC homing and to investigate the underlying mechanisms. In this study, it isfound that GEN promotes skin wound healing in HS rats, which is due at least partly to the mobilization of endogenous EPCs to the injury site via angiotensin II (Ang-II), stromal cell-derived factor-1alpha (SDF-1α), and transforming growth factor beta(TGF-β) signaling.

Nitric oxide promotes cell-matrix adhesion of endothelial progenitor cells under hypoxia condition via ITGA5 CpG promoter demethylation

Hypoxia or low oxygen tension causes changes in the structure and functional phenotype of the endothelial progenitor cells (EPCs). EPCs are found to be involved in angiogenesis and vascular repair. However, EPC's role in cell-matrix adhesion under hypoxia conditions is not clearly established. Nitric oxide (NO) exerts a wide range of biological functions, especially in regulating the mobilization and vascular repair of EPCs. In contrast, the link between NO and its role in cell-matrix deadhesion under hypoxia is not studied yet. Here, we investigated the protective role of NO in hypoxia-induced cell-matrix deadhesion of EPCs through an epigenetic mechanism. The EPCs were exposed to 2% hypoxia in the presence or absence of 10 μM Spermine NONOate (NO donor). The result demonstrates that hypoxia exposure intensified mitochondrial oxidative damage and energy defects. Using miScript miRNA qPCR array-based screening, the study found miR-148 as a novel target of hypoxia-induced DNMT1 activation. Mechanistically, the study discovered that hypoxia suppressed miR-148 levels and stimulated EPCs cell-matrix deadhesion via increasing DNMT1 mediated Integrin alpha-5 (ITGA5) CpG promoter hypermethylation. Treatment with a mitochondria-targeted antioxidant, MitoTEMPO, or epigenetic DNMT inhibitor, 5′-azacitidine, or miR-148 overexpression in hypoxic EPCs culture, prevented the cell-matrix deadhesion compared to hypoxic EPCs. Further, treatment of spNO or transient expression of eNOS-GFP attenuated hypoxia-induced cell-matrix deadhesion via inhibition of ITGA5 CpG island promoter methylation. In conclusion, the study provides evidence that NO is essential for cell-matrix adhesion of EPCs by epigenetically mitigating ITGA5 CpG promoter hypermethylation under hypoxia conditions. This finding uncovers the previously undefined mechanism of NO-mediated diminution of hypoxia-induced cell-matrix deadhesion and dysfunction induced by low oxygen tension.

Endothelial progenitor cell mobilization based on exercise volume in patients with cardiovascular disease and healthy individuals: a systematic review and meta-analysis.

Endothelial progenitor cells (EPCs) play a vital role in protecting endothelial dysfunction and cardiovascular disease (CVD). Physical exercise stimulates the mobilization of EPCs, and along with vascular endothelial growth factor (VEGF), promotes EPC differentiation, and contributes to vasculogenesis. The present meta-analysis examines the exercise-induced EPC mobilization and has an impact on VEGF in patients with CVD and healthy individuals. Database research was conducted (PubMed, EMBASE, Cochrane Library of Controlled Trials) by using an appropriate algorithm to indicate the exercise-induced EPC mobilization studies. Eligibility criteria included EPC measurements following exercise in patients with CVD and healthy individuals. A continuous random effect model meta-analysis (PROSPERO-CRD42019128122) was used to calculate mean differences in EPCs (between baseline and post-exercise values or between an experimental and control group). A total of 1460 participants (36 studies) were identified. Data are presented as standard mean difference (Std.MD) and 95% confidence interval (95% CI). Aerobic training stimulates the mobilization of EPCs and increases VEGF in patients with CVD (EPCs: Std.MD: 1.23, 95% CI: 0.70-1.76; VEGF: Std.MD: 0.76, 95% CI:0.16-1.35) and healthy individuals (EPCs: Std.MD: 1.11, 95% CI:0.53-1.69; VEGF: Std.MD: 0.75, 95% CI: 0.01-1.48). Acute aerobic exercise (Std.MD: 1.40, 95% CI: 1.00-1.80) and resistance exercise (Std.MD: 0.46, 95%CI: 0.10-0.82) enhance EPC numbers in healthy individuals. Combined aerobic and resistance training increases EPC mobilization (Std.MD:1.84, 95% CI: 1.03-2.64) in patients with CVD. Adequate exercise volume (>60%VO2max >30 min; P = 0.00001) yields desirable results. Our meta-analysis supports the findings of the literature. Exercise volume is required to obtain clinically significant results. Continuous exercise training of high-to-moderate intensity with adequate duration as well as combined training with aerobic and resistance exercise stimulates EPC mobilization and increases VEGF in patients with CVD and healthy individuals.

GDF11 promotes wound healing in diabetic mice via stimulating HIF-1ɑ-VEGF/SDF-1ɑ-mediated endothelial progenitor cell mobilization and neovascularization.

Non-healing diabetic wounds (DW) are a serious clinical problem that remained poorly understood. We recently found that topical application of growth differentiation factor 11 (GDF11) accelerated skin wound healing in both Type 1 DM (T1DM) and genetically engineered Type 2 diabetic db/db (T2DM) mice. In the present study, we elucidated the cellular and molecular mechanisms underlying the action of GDF11 on healing of small skin wound. Single round-shape full-thickness wound of 5-mm diameter with muscle and bone exposed was made on mouse dorsum using a sterile punch biopsy 7 days following the onset of DM. Recombinant human GDF11 (rGDF11, 50 ng/mL, 10 μL) was topically applied onto the wound area twice a day until epidermal closure (maximum 14 days). Digital images of wound were obtained once a day from D0 to D14 post-wounding. We showed that topical application of GDF11 accelerated the healing of full-thickness skin wounds in both type 1 and type 2 diabetic mice, even after GDF8 (a muscle growth factor) had been silenced. At the cellular level, GDF11 significantly facilitated neovascularization to enhance regeneration of skin tissues by stimulating mobilization, migration and homing of endothelial progenitor cells (EPCs) to the wounded area. At the molecular level, GDF11 greatly increased HIF-1ɑ expression to enhance the activities of VEGF and SDF-1ɑ, thereby neovascularization. We found that endogenous GDF11 level was robustly decreased in skin tissue of diabetic wounds. The specific antibody against GDF11 or silence of GDF11 by siRNA in healthy mice mimicked the non-healing property of diabetic wound. Thus, we demonstrate that GDF11 promotes diabetic wound healing via stimulating endothelial progenitor cells mobilization and neovascularization mediated by HIF-1ɑ-VEGF/SDF-1ɑ pathway. Our results support the potential of GDF11 as a therapeutic agent for non-healing DW.

Impairment of muscular endothelial cell regeneration in dermatomyositis.

Inflammatory myopathies are heterogeneous in terms of etiology, (immuno)pathology, and clinical findings. Endothelial cell injury, as it occurs in DM, is a common feature of numerous inflammatory and non-inflammatory vascular diseases. Vascular regeneration is mediated by both local and blood-derived mechanisms, such as the mobilization and activation of so-called proangiogenic cells (PACs) or early endothelial progenitor cells (eEPCs). The current study aimed to evaluate parameters of eEPC integrity in dermatomyositis (DM), compared to necrotizing myopathy (NM) and to non-myopathic controls. Blood samples from DM and NM patients were compared to non-myositis controls and analyzed for the following parameters: circulating CD133+/VEGFR-2+ cells, number of colony-forming unit endothelial cells (CFU-ECs), concentrations of angiopoietin 1, vascular endothelial growth factor (VEGF), and CXCL-16. Muscle biopsies from DM and NM subjects underwent immunofluorescence analysis for CXCR6, nestin, and CD31 (PECAM-1). Finally, myotubes, derived from healthy donors, were stimulated with serum samples from DM and NM patients, subsequently followed by RT-PCR for the following candidates: IL-1β, IL-6, nestin, and CD31. Seventeen (17) DM patients, 7 NM patients, and 40 non-myositis controls were included. CD133+/VEGFR-2+ cells did not differ between the groups. Both DM and NM patients showed lower CFU-ECs than controls. In DM, intramuscular CD31 abundances were significantly reduced, which indicated vascular rarefaction. Muscular CXCR6 was elevated in both diseases. Circulating CXCL-16 was higher in DM and NM in contrast, compared to controls. Serum from patients with DM but not NM induced a profound upregulation of mRNS expression of CD31 and IL-6 in cultured myotubes. Our study demonstrates the loss of intramuscular microvessels in DM, accompanied by endothelial activation in DM and NM. Vascular regeneration was impaired in DM and NM. The findings suggest a role for inflammation-associated vascular damage in the pathogenesis of DM.

Hyperlipidemia attenuates the mobilization of endothelial progenitor cells induced by acute myocardial ischemia via VEGF/eNOS/NO/MMP-9 pathway.

This study aims to explore the role of hyperlipidemia in the mobilization of bone marrow (BM) endothelial progenitor cells (EPCs) induced by acute myocardial ischemia (AMI). To establish the hyperlipidemia complicated with AMI (HL-AMI) model, SD rats were intragastrically administered the high-fat emulsion for 4 weeks. Then their left anterior descending arteries were ligated. Rats in each group were randomly subdivided into seven subgroups. During 1st ~ 7th day following AMI modeling, rats in 1st ~ 7th subgroups were selected to be phlebotomized from their celiac artery after being anesthetized by pentobarbitone in turn. The quantity of circulating EPCs (CEPCs) was detected by flow cytometry, the expression of VEGF, eNOS, NO, MMP-9 in myocardial tissue was analyzed by western blot, and their plasma level was assayed by ELISA. Dynamic curves were plotted using these data. Within 7 days following AMI, compared with the AMI rats, in the HL-AMI rats, the myocardial infarct size, the plasma activity of CK, CK-MB, and the collagen deposition all remained at the higher levels; meanwhile, these rats showed more significant decreases in the count of CEPCs, the plasma level of VEGF etc., and their expression in myocardial tissue (P < 0.05 or P < 0.01). Our study showed that hyperlipidemia may attenuate the mobilization of BM EPCs induced by AMI via VEGF/eNOS/NO/MMP-9 signal pathway, which might partly account for hyperlipidemia hampering the repairs of AMI-induced cardiac injury.

Preoperative exercise induces endothelial progenitor cell mobilisation in patients undergoing major surgery – A prospective randomised controlled clinical proof-of-concept trial

IntroductionPrehabilitation is increasingly recognised as a therapeutic option to reduce postoperative complications. Investigating the beneficial effects of exercise on cellular mechanisms, we have previously shown that a single episode of exhaustive exercise effectively stimulates endothelial progenitor cells (a cell population associated with vascular maintenance, repair, angiogenesis, and neovascularization) in correlation with fewer postoperative complications, despite the ongoing debate about the appropriate cell surface marker profiles of these cells (common phenotypical definitions include CD45dim, CD133+, CD34+ and/or CD31+). In order to translate these findings into clinical application, a feasible prehabilitation programme achieving both functional and cellular benefits in a suitable timeframe to expedite surgery is necessary. ObjectiveThe objective of this study was to test the hypothesis that a four-week prehabilitation programme of vigorous-intensity interval exercise training is feasible, increases physical capacity (primary outcome) and the circulatory number of endothelial progenitor cells within peripheral blood. MethodsIn this unblinded, parallel-group, randomised controlled proof-of-concept clinical trial (German Clinical Trial Register number: DRKS00000527) conducted between 01st December 2014 and 30th November 2016, fifteen female adult patients scheduled for incontinence surgery with abdominal laparotomy at the University Hospital Cologne were allocated to either an exercise (n = 8, exclusion of 1 patient, analysed n = 7) or non-exercise group (n = 7, exclusion of 1 patient, analysed n = 6). The exercise group's intervention consisted of a vigorous-intensity interval training for four weeks preoperatively. Cardiopulmonary Exercise Testing accompanied by peripheral blood collection was performed before and after the (non-)training phase. Cellular investigations were conducted by flow cytometry and cluster-based analyses. ResultsVigorous-intensity interval training over four weeks was feasible in the exercise group (successful completion by 8 out of 8 patients without any harms), with significant improvements in patients' functional capacity (increased oxygen uptake at anaerobic threshold [intervention group mean + 1.71 ± 3.20 mL/min/kg vs. control group mean −1.83 ± 2.14 mL/min/kg; p = 0.042] and peak exercise [intervention group mean + 1.71 ± 1.60 mL/min/kg vs. control group mean −1.67 ± 1.37 mL/min/kg; p = 0.002]) and a significant increase in the circulatory number of endothelial progenitor cells (proportionate CD45dim/CD14dim/CD133+/CD309+/CD34+/CD31 + subpopulation within the circulating CD45-pool [p = 0.016]). ConclusionsWe introduce a novel prehabilitation concept that shows effective stimulation of an endothelial progenitor cell subpopulation within four weeks of preoperative exercise, serving as a clinical cell-mediated intervention with the aim to reduce surgical complications. FundingInstitutional funding. DFG (German Research Foundation, 491454339) support for the Article Processing Charge.

Melatonin Improves Ischemia-Induced Circulation Recovery Impairment in Mice with Streptozotocin-Induced Diabetes by Improving the Endothelial Progenitor Cells Functioning.

Patients with diabetes mellitus tend to develop ischemia-related complications and have compromised endothelial progenitor cell (EPC) function. Melatonin protects against ischemic injury, possibly via EPC modulation. We investigated whether melatonin pretreatment could restore EPC function impairment and improve circulation recovery in a diabetic critical limb ischemia mouse model. Under 25 mM high-glucose medium in vitro, EPC proliferation, nitric oxide production, tube formation, and endothelial nitric oxide synthase (eNOS) phosphorylation were significantly suppressed. Hyperglycemia promoted EPC senescence and apoptosis as well as increased reactive oxygen species (ROS) production. Melatonin treatment reversed the harmful effects of hyperglycemia on EPC through adenosine monophosphate–activated protein kinase-related mechanisms to increase eNOS phosphorylation and heme oxygenase-1 expression. In an in-vivo study, after a 4-week surgical induction of hindlimb ischemia, mice with streptozotocin (STZ)-induced diabetes showed significant reductions in new vessel formation, tissue reperfusion, and EPC mobilization in ischemic hindlimbs compared to non-diabetic mice. Mice with STZ-induced diabetes that received melatonin treatment (10 mg/kg/day, intraperitoneal) had significantly improved blood perfusion ratios of ischemic to non-ischemic limb, EPC mobilization, and densities of capillaries. In addition, a murine bone marrow transplantation model to support these findings demonstrated that melatonin stimulated bone marrow-originated EPCs to differentiate into vascular endothelial cells in femoral ligation-induced ischemic muscles. In summary, this study suggests that melatonin treatment augments EPC function along with neovascularization in response to ischemia in diabetic mice. We illustrated the protective effects of melatonin on EPC H2O2 production, senescence, and migration through melatonin receptors and modulating eNOS, AMPK, and HO-1 activities at the cellular level. Thus, melatonin might be used to treat the impairment of EPC mobilization and circulation recuperation in response to ischemic injury caused by chronic hyperglycemia. Additional studies are needed to elucidate the applicability of the results in humans.

The Inhibitory Effect of Regulatory T Cells on the Intimal Hyperplasia of Tissue-Engineered Blood Vessels in Diabetic Pigs.

Severe inflammatory response and functional impairment of endothelial progenitor cells (EPCs) often lead to the implantation failure of EPC-captured tissue-engineered blood vessels (TEBVs) in diabetes. Regulatory T cells (Treg cells) are the most important inhibitory immune cells, but their effects in angiogenesis remain undefined, and the differences in the microenvironment may be an important reason. Here, we constructed a TEBV coated with an anti-CD34 antibody-functionalized heparin-collagen multilayer (anti-CD34 antibody-modified TEBV) using layer-by-layer self-assembly. Then, TEBVs were implanted into diabetic pigs. All TEBVs remained unobstructed 60 days after implantation, although varying degrees of intimal hyperplasia were detectable. Severe intimal hyperplasia was observed in the control group and peripheral injection of Treg cells group. Intravenous injection of Treg cells significantly inhibited intimal hyperplasia, inflammation, and cell apoptosis. Moreover, intravenous injection increased the proportion of circulating EPCs, while peripheral injection did not have these effects and reduced microvessel density around the TEBV. Interestingly, many Nestin+ cells could be detected in TEBVs, most of which were fusiform, showing the characteristics of smooth-muscle cells. Treg cell intravenous transplantation markedly reduced the number of Nestin+ cells in the TEBV. In conclusion, Treg cells inhibited the intimal hyperplasia of TEBVs in diabetic pigs by promoting EPC mobilization, anti-inflammatory action, and cellular protection.

Exercise Training Effects on Circulating Endothelial and Progenitor Cells in Heart Failure

Heart failure (HF) is a major public health issue worldwide with increased prevalence and a high number of hospitalizations. Patients with chronic HF and either reduced ejection fraction (HFrEF) or mildly reduced ejection fraction (HFmrEF) present vascular endothelial dysfunction and significantly decreased circulating levels of endothelial progenitor cells (EPCs). EPCs are bone marrow-derived cells involved in endothelium regeneration, homeostasis, and neovascularization. One of the unsolved issues in the field of EPCs is the lack of an established method of identification. The most widely approved method is the use of monoclonal antibodies and fluorescence-activated cell sorting (FACS) analysis via flow cytometry. The most frequently used markers are CD34, VEGFR-2, CD45, CD31, CD144, and CD146. Exercise training has demonstrated beneficial effects on EPCs by increasing their number in peripheral circulation and improving their functional capacities in patients with HFrEF or HFmrEF. There are two potential mechanisms of EPCs mobilization: shear stress and the hypoxic/ischemic stimulus. The combination of both leads to the release of EPCs in circulation promoting their repairment properties on the vascular endothelium barrier. EPCs are important therapeutic targets and one of the most promising fields in heart failure and, therefore, individualized exercise training programs should be developed in rehabilitation centers.