Circulating Endothelial Progenitor Cells Research Articles

Mobilization of endothelial progenitor cells after implantation of CD34 antibody-covered sirolimus-eluting COMBO® stent: assessment with EPC colony-forming assay.

The COMBO® stent is a unique stent on which the CD34 antibody is mounted to capture CD34 + endothelial progenitor cells (EPCs) and from which sirolimus is eluted to suppress neointimal hyperplasia. The COMBO® stent aims to induce early re-endothelialization and vascular healing and to prevent restenosis. In the clinical setting, however, the effects of the COMBO® stent have not been validated in terms of EPC biology. In this study, we assessed the kinetics of circulating EPCs, not only quantitatively by flow cytometric analysis but also qualitatively by an EPC colony-forming assay, in 25 patients undergoing COMBO® stent implantation. Among all patients, flow cytometric analysis indicated that the number of circulating CD34 + /KDR + EPCs did not change after COMBO® stent implantation compared with baseline (before stent implantation). The EPC colony-forming assay demonstrated that the number of small-type EPC colonies increased on day 2 (3 [2, 9] to 6 [4, 9]/dish, P = 0.026) and that of large-type EPC colonies more prominently increased on day 2 (1 [0, 4] to 5 [1, 10]/dish, P < 0.001) and day 7 (to 2 [1, 7], P = 0.006) after COMBO® stent implantation. Based on the results of optical coherence tomography at 3months after stent implantation, the patients were divided into two groups: well (uncovered strut ratio < 10%, n = 14) and poor (uncovered strut ratio ≥ 10%, n = 10) stent coverage. Compared with baseline values, the number of large-type EPC colonies increased on day 2 (2.9 ± 0.8 to 7.3 ± 2.0, P = 0.026) and tended to increase on day 7 (6.8 ± 2.0/dish, P = 0.062) after COMBO® stent implantation in the well coverage group, while it did not change in the poor coverage group. Thus, the COMBO® stent might induce mature EPCs in the circulation, which might be associated with subsequent healing processes in vessel sites with stent-induced injury.

Human Cord Blood Endothelial Progenitor Cells and Pregnancy Complications (Preeclampsia, Gestational Diabetes Mellitus, and Fetal Growth Restriction).

Hemangioblasts give rise to endothelial progenitor cells (EPCs), which also express the cell surface markers CD133 and c-kit. They may differentiate into the outgrowth endothelial cells (OECs) that control neovascularization in the developing embryo. According to numerous studies, reduced levels of EPCs in circulation have been linked to human cardiovascular disorders. Furthermore, preeclampsia and senescence have been linked to levels of EPCs produced from cord blood. Uncertainties surround how preeclampsia affects the way EPCs function. It is reasonable to speculate that preeclampsia may have an impact on the function of fetal EPCs during the in utero period; however, the present literature suggests that maternal vasculopathies, including preeclampsia, damage fetal circulation. Additionally, the differentiation potential and general activity of EPCs may serve as an indicator of the health of the fetal vascular system as they promote neovascularization and repair during pregnancy. Thus, the purpose of this review is to compare-through the assessment of their quantity, differentiation potency, angiogenic activity, and senescence-the angiogenic function of fetal EPCs obtained from cord blood for normal and pregnancy problems (preeclampsia, gestational diabetes mellitus, and fetal growth restriction). This will shed light on the relationship between the angiogenic function of fetal EPCs and pregnancy complications, which could have an effect on the management of long-term health issues like metabolic and cardiovascular disorders in offspring with abnormal vasculature development.

PD-L1-positive circulating endothelial progenitor cells associated with immune response to PD-1 blockade in patients with head and neck squamous cell carcinoma.

A number of the inhibitors against programmed death protein 1 (PD-1) have been approved to treat recurrent or metastatic squamous cell carcinoma of head and neck (HNSCC). The interaction between PD-1 and its ligand (PD-L1) serves as an immune checkpoint that governs cytotoxic immune effectors against tumors. Numerous clinical trials of PD-1/PD-L1 inhibitors have so far been discordant about having sufficient PD-L1 expression in the tumor as a prerequisite for a successful anti-PD-1 treatment. On the other hand, vascular endothelial cells modulate immune activities through PD-L1 expression, and thus it is possible that the expressions of circulating endothelial cells (CECs) and circulating endothelial progenitor cells (CPCs) could affect antitumor immunity as well as neoangiogenesis. Here we investigated the potential involvement of PD-L1+ CECs and PD-L1+ CPCs in PD-1 blockade treatments for HNSCC patients. We measured CD8+ T cells, CECs, and CPCs in the peripheral blood of the HNSCC patients treated by anti-PD-1 therapies. We found that their PD-L1+ CPC expression before anti-PD1 therapies was strongly correlated with treatment responses and overall survival. Moreover, if the first infusion of PD-1 inhibitors reduced ≥ 50% PD-L1+ CPCs, a significantly better outcome could be predicted. In these patients as well as in an animal model of oral cancer, Pd-l1+ CPC expression was associated with limited CD8+ T-cell infiltration into the tumors, and anti-PD-1 treatments also targeted Pd-l1+ CPCs and increased CD8+ T-cell infiltration. Our results highlight PD-L1+ CPC as a potential regulator in the anti-PD-1 treatments for HNSCC.

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.

Circulating progenitor cells and outcomes in patients with coronary artery disease

BackgroundLow quantities of circulating progenitor cells (CPCs), specifically CD34+ populations, reflect impairment of intrinsic regenerative capacity. This study investigates the relationship between subsets of CPCs and adverse outcomes. Methods1366 individuals undergoing angiography for evaluation of coronary artery disease (CAD) were enrolled into the Emory Cardiovascular Biobank. Flow cytometry identified CPCs as CD45med blood mononuclear cells expressing the CD34 epitope, with further enumeration of hematopoietic CPCs as CD133+/CXCR4+ cells and endothelial CPCs as vascular endothelial growth factor receptor-2 (VEGFR2+) cells. Adjusted Cox or Fine and Gray's sub-distribution hazard regression models analyzed the relationship between CPCs and 1) all-cause death and 2) a composite of cardiovascular death and non-fatal myocardial infarction (MI). ResultsOver a median 3.1-year follow-up period (IQR 1.3–4.9), there were 221 (16.6%) all-cause deaths and 172 (12.9%) cardiovascular deaths/MIs. Hematopoietic CPCs were highly correlated, and the CD34+/CXCR4+ subset was the best independent predictor. Lower counts (≤median) of CD34+/CXCR4+ and CD34+/VEGFR2+ cells independently predicted all-cause mortality (HR 1.46 [95% CI 1.06–2.01], p = 0.02 and 1.59 [95% CI 1.15–2.18], p = 0.004) and cardiovascular death/MI (HR 1.50 [95% CI 1.04–2.17], p = 0.03 and 1.47 [95% CI 1.01–2.03], p = 0.04). A combination of low CD34+/CXCR4+ and CD34+/VEGFR2+ CPCs predicted all-cause death (HR 2.1, 95% CI 1.4–3.0; p = 0.0002) and cardiovascular death/MI (HR 2.0, 95% CI 1.3–3.2; p = 0.002) compared to those with both lineages above the cut-offs. ConclusionsLower levels of hematopoietic and endothelial CPCs indicate diminished endogenous regenerative capacity and independently correlate with greater mortality and cardiovascular risk in patients with CAD.

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.

A Meta-Analysis of the Effects of Aerobic Exercise on the Basal Level of Endothelial Progenitor Cells in Middle-Aged and Older Adults.

Circulatory endothelial progenitor cells (EPCs) play an important role in repairing damaged vascular endothelium and preventing cardiovascular diseases. The decrease in level of circulating EPCs in middle-aged and older adults can lead to an increase in cardiovascular events. Researchers have carried out several studies on the effects of aerobic exercise on circulating EPCs in middle-aged and older adults, but the results vary from one study to another. The aim of this study therefore is to systematically evaluate the effect of aerobic exercise on the basal level of circulating EPCs in middle-aged and older adults by meta-analysis. Randomized controlled trial studies on the effects of aerobic exercise on EPCs were searched for from CNKI, PubMed, EBSCO, Cochrane Library, Web of Science, and Embase databases. The literature was screened according to inclusion and exclusion criteria, research data were extracted, and the literature quality was evaluated by Cochrane scale. Software Review Manager (version 5.3) and Stata (version 15.0) were used for data analysis. A total of nine articles were included in this analysis, including 165 participants (40 healthy adults and 125 patients) who received exercise interventions and 162 participants (40 healthy adults and 122 patients) who served as the control, with an age range from 58 to 70years. The meta-analysis found that long-term (≥12weeks) aerobic exercise could improve the level of EPCs in the peripheral circulation (standardized mean differences [SMD] = 0.53, 95% confidence interval [0.30, 0.76], p < .01). The subgroup analysis found that aerobic exercise improved EPCs in healthy people better than in people with cardiovascular disease and that the intervention time needs to be over 12weeks to have a significant impact. In conclusion, the authors suggest that middle-aged and older adults can improve their EPCs quantity by engaging in moderate-intensity aerobic exercise four to five times per week for no less than 12weeks to reduce the risk of cardiovascular disease.

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.

Gualou-Xiebai-Banxia decoction protects against type II diabetes with acute myocardial ischemia by attenuating oxidative stress and apoptosis via PI3K/Akt/eNOS signaling.

Gualou-Xiebai-Banxia decoction has a long history of medical use for treating cardiovascular diseases in China. In this study, we investigated the protective effect and underlying mechanisms GXB in type II diabetes with acute myocardial ischemia (T2DM-AMI) rats. We hypothesized that GXB may display its protective effect on T2DM-AMI by reducing endothelial progenitor cells (EPCs) apoptosisviaactivating PI3K (phosphatidyl inositol 3-kinase)/Akt (serine/threonine protein kinase B)/eNOS (endothelial nitric oxide synthase) signaling. Rats were challenged with a high-fat diet and intraperitoneal injection of streptozotocin to induce a model of type II diabetes mellitus (T2DM) and coronary ligation to induce acute myocardial infarction (AMI). Changes in metabolites were assessed via enzyme-linked immunoassay and biochemical examination. The number and apoptosis rate of EPCs in peripheral blood were detected by flow cytometry. Target mRNAs and proteins in EPCs were analyzed by RT-PCR and Western blot analysis. The results demonstrated that GXB treatment decreased T2DM-AMI-associated changes in plasma fasting blood glucose, muscular enzymes, and blood lipids, and reduced oxidative stress. Furthermore, EPC apoptosis was increased in T2DM-AMI rats and was associated with decreased mRNA and protein levels of PI3K, Akt, and eNOS compared to the controls. Conversely, T2DM-AMI rats treated with GXB exhibited more circulating EPCs and downregulated levels of cell apoptosis, combined with increased mRNA and protein levels of PI3K, Akt, and eNOS compared to those of untreated T2DM-AMI rats. Our study showed that GXB treatment mitigated EPC apoptosis and promoted PI3K/Akt/eNOS signaling in T2DM-AMI rats.

A microfluidic robot for rare cell sorting based on machine vision identification and multi-step sorting strategy

The identification, sorting and analysis of rare target single cells in human blood has always been a clinically meaningful medical challenge. Here, we developed a microfluidic robot platform for sorting specific rare cells from complex clinical blood samples based on machine vision-based image identification, liquid handling robot and droplet-based microfluidic techniques. The robot integrated a cell capture and droplet generation module, a laser-induced fluorescence imaging module, a target cell identification and data analysis module, and a system control module, which could automatically achieve the scanning imaging of cell array, cell identification, capturing, and droplet generation of rare target cells from blood samples containing large numbers of normal cells. Based on the robot platform, a novel “gold panning” multi-step sorting strategy was proposed to achieve the sorting of rare target cells in large-scale cell samples with high operation efficiency and high sorting purity (>90%). The robot platform and the multi-step sorting strategy were applied in the sorting of circulating endothelial progenitor cells (CEPCs) in human blood to demonstrate their feasibility and application potential in the sorting and analysis of rare specific cells. Approximately 1,000 CEPCs were automatically identified from 3,000,000 blood cells at a scanning speed of ca. 4,000 cells/s, and 20 25-nL droplets containing single CEPCs were generated.

Candesartan treatment enhances liposome penetration and anti-tumor effect via depletion of tumor stroma and normalization of tumor vessel.

The poor penetration of nanoparticles in solid tumors has been a critical factor limiting the clinical benefits of nanomedicine. Therefore, we depleted the dense extracellular matrix (ECM) and normalized tumor vessels to enhance drug delivery and therapeutic efficacy. We used candesartan as an angiotensin system inhibitor, which reduced ECM content and facilitated "vascular normalization" by targeting the angiotensin-signaling axis, resulting in improved anti-cancer therapeutic effects. We also combined candesartan with PEGylated liposome-encapsulated zoledronic acid (ZOL) (PEG-ZOL-LPs) to assess how this affected anti-tumor therapy. Our findings indicated that the migration of 4T1 mouse breast cancer cells was inhibited by candesartan. Moreover, the ECM depletion (including collagen I and hyaluronan) by candesartan was achieved through the downregulation of TGF-β1 in vitro, consistent with in vivo results. Furthermore, treatment groups that received candesartan also had significantly decreased tumor vessel permeability and proportions of circulating endothelial progenitor cells (CEPCs) in the serum, which resulted in normalization of tumor vasculature and improved delivery of PEG-ZOL-LPs. Finally, the positive effect candesartan in terms of tumor growth was found not to have an impact of the efficacy of the PEG-ZOL-LPs treatment. This unexpected lack of effect of candesartan on the performance of PEG-ZOL-LPs would be due to dynamics of the effect of both treatments. It might be possible that a different protocol of administration could lead to a synergistic effect. Graphical abstract The schematic illustration showed that candesartan favored depletion of tumor stroma and tumor vascular normalization to improve the anti-cancer efficacy of PEG-ZOL-LPs.

Metoprolol rescues endothelial progenitor cell dysfunction in diabetes.

Added risk portended by diabetes in addition to hypertension has been related to an amplification of endothelial dysfunction. β-blockers are widely used for cardiovascular diseases and improve the endothelial function compared with a placebo. However, the effect of β-blockers on the endothelial progenitor cells (EPCs) function in diabetes is still unknown. Five β-blockers (metoprolol, atenolol, propranolol, bisoprolol, and nebivolol) were tested in EPC functional screening. Metoprolol improved EPC function significantly among the five β-blockers and was chosen for the in vivo tests in STZ induced diabetic mice. Reactive hyperemia peripheral arterial tonometry (RH-PAT) measurements were performed using the Endo-PAT2000 device in diabetic patients. Metoprolol, but not other β-blockers, improved EPC function in both tube formation and migration assay. EPC function was significantly decreased in diabetic mice, and metoprolol treatment restored damaged EPC migration capabilities and circulation EPC number. Metoprolol treatment promoted wound healing and stimulated angiogenesis in diabetic mice. Furthermore, metoprolol significantly enhanced eNOS phosphorylation and decreased O2− levels in EPCs of diabetic mice. In clinical trials, the RH-PAT index was significantly higher in metoprolol-treated versus bisoprolol-treated diabetics. Metoprolol could accelerate wound healing in diabetic mice and improve endothelial function in diabetic subjects, which may be mediated in part by improving impaired EPC function.

Indoxyl sulfate impairs valsartan-induced neovascularization

Studies revealed that the use of renin-angiotensin-aldosterone system antagonism is not associated with a statistically significant reduction in the risk of cardiovascular events in patients with chronic kidney disease (CKD) compared with that in the general population. We tested the hypothesis that indoxyl sulfate (IS) can interfere with the protective effect of valsartan-mediated on endothelial function in vitro and neovascularization in mice underwent subtotal nephrectomy. In human aortic endothelial cells, we first demonstrated that IS impaired the valsartan-mediated phosphorylation of eNOSThr495, nitric oxide production and tube formation via NADPH oxidase (NOX) and protein kinase C (PKC) phosphorylation, but this effect was suppressed by cotreatment with apocynin and calphostin C. In vivo, IS attenuated valsartan-induced angiogenesis in Matrigel plugs in mice. Moreover, in subtotal nephrectomy mice who underwent hindlimb ischemic surgery, valsartan significantly increased the mobilization of endothelial progenitor cells in circulation as well as the reperfusion of blood flow and density of CD31+ capillaries in ischemic limbs. However, IS attenuated the protective effect of valsartan-induced neovascularization and increased the expression of p-PKCαSer657 and p-eNOSThr497 in ischemic limbs. Cotreatment of apocynin and calphostin C reversed the IS impaired-neovascularization and decreased the expression of p-PKCαSer657 and p-eNOSThr497 in ischemic limbs. Our study suggests that the NOX/PKC/eNOS signaling pathway plays a pivotal role in the IS-mediated inhibition of valsartan-conferred beneficial effects on endothelial function in vitro and neovascularization in subtotal nephrectomy mice. We proposed a novel causative role for IS in cardiovascular complications in CKD patients.

Natural Killer Cells Contribute to Pathogenesis of Severe Alcoholic Hepatitis by Inducing Lysis of Endothelial Progenitor Cells.

Endothelial progenitor cells (EPCs) help in neovascularization and endothelial repair during injury. Patients with cirrhosis show increased number and function of EPCs in circulation. Since natural killer (NK) cells regulate EPCs, we investigated the relationship between the 2 in alcoholic cirrhosis (AC, n=50) and severe alcoholic hepatitis (SAH, n=18) patients and compared with nonalcoholic cirrhosis (n=15) and healthy controls (HC, n=30). Levels of systemic inflammatory cytokines were measured, and coculture assays were performed between EPCs and NK cells in contact-dependent and contact-independent manner. NK cell-mediated killing of EPCs was evaluated, and expression of receptors including fractalkine (FKN) on EPCs and its cognate receptor CX3CR1 on NK cells was studied by RT-PCR assays. Patients with SAH had higher regulated on activation, normal T cell expressed and secreted (RANTES) (p=0.01), vascular endothelial growth factor (VEGF) (p=0.04), IL-1β (p=0.04), and IL-6 (p=0.00) growth factors and proinflammatory cytokines as compared to AC and HC. Distinct populations of CD31+ CD34+ EPCs with low and high expression of CD45 were significantly lower in SAH than HC (CD45low , p=0.03; CD45hi , p=0.04) and AC (CD45low , p=0.05; CD45hi , p=0.02). SAH patients, however, showed increased functional capacity of EPCs including colony formation and LDL uptake. NK cells were reduced in SAH compared with AC (p=0.002), however with higher granzyme ability (p<0.001 and p=0.04, respectively). In SAH, EPC-NK cell interaction assays showed that NK cells lysed the EPCs in both contact-dependent and contact-independent assays. Expression of interaction receptor CX3CR1 was significantly higher on NK cells (p=0.0005), while its cognate receptor, FKN, was increased on EPCs in SAH patients as compared to HC (p=0.0055). We conclude that in SAH, NK cells induce killing of EPCs via CX3CR1/FKN axis that may be one of the key events contributing to disease severity and proinflammatory responses in SAH.

Combination of metronomic administration and target delivery strategies to improve the anti-angiogenic and anti-tumor effects of triptolide.

The metronomic administration of a low-dose cytotoxic agent with no prolonged drug-free breaks is an anti-angiogenic cancer treatment method. The use of nano-formulations in this manner enhances anti-tumor efficacy and reduces toxicity by inhibiting angiogenic activity, reduces adverse effects, and changes the biodistribution of TP in the body, steering TP away from potentially endangering healthy tissues. The present study uses liposomes and Asn-Gly-Arg (NGR) peptide conjugated aminopeptidase N(APN)-targeted liposomes for triptolide (TP), as a model for the investigation of targeted metronomic administration and subsequent effects on the toxicity profile and efficacy of the chemotherapeutic agent. Metronomic NGR-PEG-TP-LPs have been found to have enhanced anti-tumor activity, a phenomenon that is attributed to an increase in angiogenic inhibition properties. In vitro experiments demonstrate that the viability, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) are obviously suppressed in comparison with that of other treatment groups. In vivo experiments also demonstrate that the anti-tumor efficacy of targeted metronomic administration is superior to that of liposome-administered treatments given at maximum tolerated dose (MTD) schemes, as is evidenced by markedly decreased tumor volume, vessel density, and the volume of circulating endothelial progenitor cells (CEPCs) in serum. Moreover, we observed that the metronomic administration of NGR-PEG-TP-LPs could elevate thrombospondin-1 (TSP-1) expression in tumors, a finding that is consistent with the promotion of TSP-1 secretion specifically from HUVECs. Additionally, metronomic NGR-PEG-TP-LPs have minimal drug-associated toxicity (weight loss, hepatotoxicity and nephrotoxicity in mice). Our research demonstrates the significance of targeted metronomic administration using liposomes for anti-angiogenic cancer therapy.

Association between Advanced Glycation End Products, Soluble RAGE Receptor, and Endothelium Dysfunction, Evaluated by Circulating Endothelial Cells and Endothelial Progenitor Cells in Patients with Mild and Resistant Hypertension.

The aim of the present study was to evaluate advanced glycation end products (AGEs) and soluble form of receptor RAGE (sRAGE) concentrations as well as the AGEs/sRAGE ratio in mild (MH) and resistant (RH) hypertensive patients in comparison with normotensive individuals. We also evaluated the association between AGEs, sRAGE as well as AGEs/sRAGE ratio and circulating endothelial cells (CECs) and circulating endothelial progenitor cells (CEPCs). The MH group consisted of 30 patients, whereas 30 patients were classified for the RH group. The control group (C) included 25 normotensive volunteers. AGEs and sRAGE were measured using enzyme-linked-immunosorbent assay (ELISA). The multicolor flow cytometry was used for analysis of CECs and CEPCs. Significantly higher levels of AGEs in RH cohort were observed as compared to C cohort. Furthermore, significantly lower sRAGE levels as well as a higher AGEs/sRAGE ratio were observed between MH and RH cohorts. Significant correlations were found in the MH cohort for sRAGE and CECs, and CEPCs. The elevation of AGEs levels suggests that oxidative modification of proteins occurs in hypertension pathogenesis. The decrease in sRAGE levels and elevation of the AGEs/sRAGE ratio in MH and RH groups may suggest that hypertensive patients are less protected against the side effects of AGEs as a consequence of an insufficient competitive role of sRAGE against the AGEs-RAGE axis. Finally, it may be concluded that the level of AGEs may be an independent predictor of the condition and function of the endothelium. Furthermore, sRAGE may be classified as a potential biomarker of inflammation and endothelium dysfunction.

Endothelial Activation Markers as Disease Activity and Damage Measures in Juvenile Dermatomyositis.

Circulating endothelial cells (CEC), von Willebrand factor (vWF) antigen, P-selectin, and thrombomodulin are released from damaged endothelium, while decreases in circulating endothelial progenitor cells (CEPC) have been associated with poor vascular outcomes. We examined these markers in the peripheral blood of patients with juvenile dermatomyositis (JDM) and their correlations with disease assessments. Peripheral blood endothelial cells and biomarkers were assessed in 20 patients with JDM and matched healthy controls. CEC and CEPC were measured by flow cytometry, while vWF antigen and activity, factor VIII, P-selectin, and thrombomodulin were measured in plate-based assays. Disease activity and damage, nailfold capillary density, and brachial artery flow dilation were assessed. Serum cytokines/chemokines were measured by Luminex. CEC, vWF antigen, factor VIII, and thrombomodulin, but not vWF activity, CEPC, or P-selectin, were elevated in the peripheral blood of patients with JDM. CEC correlated with pulmonary activity (rs = 0.56). The vWF antigen correlated with Patient's/Parent's Global, cutaneous, and extramuscular activity (rs = 0.47-0.54). CEPC negatively correlated with muscle activity and physical function (rs = -0.52 to -0.53). CEPC correlated inversely with endocrine damage. The vWF antigen and activity correlated with interleukin 10 and interferon-gamma inducible protein-10 (rs = 0.64-0.82). Markers of endothelial injury are increased in patients with JDM and correlate with extramuscular activity. CEPC correlate inversely with muscle activity, suggesting a functional disturbance in repair mechanisms.

Pentoxifylline ameliorates chronic stress/high-fat diet-induced vascular wall disease: the role of circulating endothelial progenitor cells.

Depression and cardiovascular disease (CVD) are two faces of one coin. A pro-inflammatory state was previously suggested in the pathology of both diseases. We investigated the effect of chronic administration (2weeks) of imipramine (20mg/kg/day) and pentoxifylline (50mg/kg/day) on behavioral, aortic histological abnormalities, and level of circulating endothelial progenitor cells (CEPCs) in peripheral blood of male Wistar rats exposed to chronic mild stress (CMS) and high-fat diet. Exposure to CMS and high-fat diet induced a depressive-like behavior alongside aortic immunohistochemical changes associated with an increase in aortic TNF-α level. Markers of CEPCs, VEGFR-2 and CD133, were significantly disturbed in aortic sections, as compared to control animals and those exposed to CMS while fed high-fat diet, although flowcytometric analysis did not show any significant changes in the level of CEPCs in peripheral blood. Chronic pentoxifylline treatment was more effective in ameliorating the histological changes and endothelial damage compared to imipramine. Pro-inflammatory cytokines-induced disturbances in CEPCs could constitute a plausible link between depression and atherosclerotic cardiovascular disease. Current antidepressants reduce symptoms of depression without tackling the underlying link between it and cardiovascular disease. Targeting pro-inflammatory cytokines might open a new therapeutic approach to alleviate depression and reduce the risk of mortality from cardiovascular disease.

Systemic microcirculation dysfunction after low thoracic spinal cord injury in mice

BackgroundSpinal cord injury (SCI) disturbs the autonomic nervous system and induces dysfunction or failure of multiple organs. The systemic microcirculation disturbance that contributes to the complications associated with SCI remains to be clarified. MethodsWe used male mice (29–32 g) and modified weight-drop injury at T10 to evaluate the systemic microcirculation dysfunction during the first 2 weeks after SCI. We determined permeability and microvascular blood flow in several organs and evaluated their vasomotor function. We also measured circulating endothelial cells (CECs), circulating endothelial progenitor cells (CEPCs), circulating pericyte progenitor cells (CPPCs), and serum proinflammatory cytokines. ResultsThe endothelial permeability of almost all organs increased after SCI. Microvascular blood flow decreased in the bladder and kidney and increased in the spleen and was accompanied by endothelial vasomotor dysfunction. SCI also induced an increase in CECs, CEPCs, and CPPCs in peripheral blood. Finally, we confirmed changes in a systemic cytokine profile (interleukin [IL]-3, IL-6, IL-10, IL-13, granulocyte colony-stimulating factor, and regulated on activation normal T cell expressed and secreted) after SCI. ConclusionsThese data indicate that a systemic microcirculation disturbance occurs after SCI. This information may play a key role in the development of effective therapeutic strategies for SCI.

Velvet Antler Mobilizes Endothelial Progenitor Cells to Promote Angiogenesis and Repair Vascular Endothelial Injury in Rats Following Myocardial Infarction.

Objective: This investigation examined the effect of velvet antler (VA) on endothelial progenitor cells (EPCs) and the associated effects to promote angiogenesis and repair vascular endothelial injury in rats with myocardial infarction (MI).Methods: VA was analyzed by liquid chromatography-mass spectrometry. Male Sprague Dawley rats were randomly divided into four groups: sham, MI, VA, and VA + DAPT (gamma-secretase inhibitor IX, a specific blocker of the Notch signaling pathway) group. The rats underwent ligation of the left anterior descending coronary artery for the establishment of MI. Sham-operated rats were used as controls. Blood was taken from the orbital plexus on the first and third days after the operation, and all rats were euthanized on the 7th day after surgery. The blood samples were used to detect the contents of circulating endothelial progenitor cells (CEPCs) and vascular endothelial growth factor (VEGF). Echocardiography was used to test the cardiac function. Cardiac tissue was used for immunohistochemistry and electron microscope, and the marginal zone of the MI tissue was used for western blot and reverse transcription-quantitative polymerase chain reaction.Results: The number of basically qualitative metabolites is 445. Among them, there are 74 substances with relative content greater than 0.05%. VA increased the concentration of CEPCs and VEGF in serum, CD133 content and microvessel density (MVD), and protected the morphology of microvascular endothelial cells in the marginal area of MI at 7 days post-MI surgery. CEPCs and MVD in the VA +DAPT group were lower than those of VA group. VA increased the protein expressions of Jagged-1, Notch1, NICD and HES1, and the mRNA expressions of Hes1 and Hey2, while some of the effects could be suppressed by DAPT.Conclusion: These results suggest that VA promotes the mobilization of EPCs to promote angiogenesis and repair vascular endothelial cell damage in post-MI rats, and these effects may be due to activation of the Notch signal pathway.