Search Results (148)

The aim of this study is to assess endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) at the time of type 1 diabetes (T1D) recognition concerning patients’ clinical state, remaining insulin secretion, and further partial remission (PR) occurrence. We recruited 45 children that were admitted to hospital due to newly diagnosed T1D (median age 10.8 yrs), and 20 healthy peers as a control group. EPC and CEC levels were measured at disease onset in PBMC isolated from whole peripheral blood with the use of flow cytometry. Clinical data regarding patients’ condition, C-peptide secretion, and further PR prevalence were analyzed. T1D-diagnosed patients presented higher EPC levels than the control group (p = 0.026), while no statistical differences in CEC levels and EPC/CEC ratio were observed. Considering only T1D patients, those with better clinical conditions presented lower EPCs (p = 0.021) and lower EPC/CEC ratios (p = 0.0002). Patients with C-peptide secretion within a normal range at disease onset presented lower EPC/CEC ratios (p = 0.027). Higher levels of EPCs were observed more frequently in patients with higher glucose, decreased fasting C-peptide, and lower stimulated C-peptide (all p < 0.05). The presence of DKA was related to higher EPC/CEC ratios (p = 0.034). Significantly higher levels of CECs were observed in patients who presented partial remission of the disease at 6 months after diagnosis (p = 0.03) only. In the study group, positive correlations of CECs with age, BMI at onset, and BMI in following years were observed. EPC/CEC ratios correlated positively with glucose levels at hospital admission and negatively with age, BMI, pH, and stimulated C-peptide level. We reveal a new potential for the application of EPCs and CECs as biomarkers, reflecting both endothelial injury and reconstruction processes in children with T1D. There is a need for further research in order to reduce cardiovascular risk in children with T1D. Full article

Endothelial progenitor cells (EPC) are considered to support neovascularization and endothelial repair by being incorporated into newly formed or injured vessels and by improving vascularization in a paracrine manner by secreting proangiogenic factors. Here, we studied the role of gap junctional communication between EPC and endothelial cells in long-term co-cultures in vitro. The cultivation of endothelial cells together with mouse embryonic EPC (E 7.5) induced the spontaneous formation of angiogenic networks after 3–6 days consisting of both cell types, but not in the respective monocultures, whereas their respective cultivation on a basement matrix induced the formation of tube-like structures, as expected. The angiogenic network formation could not be mimicked by the incubation of endothelial cells with supernatants of EPC only. We therefore hypothesized that direct interaction and cell-cell communication is required to induce the angiogenic network formation in co-cultures with endothelial cells. Expression analysis demonstrated expression of the gap junctional protein connexin 43 (Cx43) in EPC. Moreover, dye injection studies as well as FACS analysis identified gap junctional communication between endothelial cells and EPC. The inhibition of gap junctions by pharmacological blockers significantly reduced the angiogenic network formation, confirming that gap junctional communication between both cell types is required for this process. Full article

Non-traumatic intracerebral hemorrhage (ICH) is one of the most devastating and disabling forms of stroke; however, there are no effective pharmacological therapies available following the insult. Angiogenesis appears as a key step to overcoming the damage and promoting functional recovery. In this context, endothelial progenitor cells (EPCs) mobilization improves oxidative stress and promotes neovascularization, which has been linked to beneficial outcomes following both ischemic and hemorrhagic stroke. The TNF-like weak inducer of apoptosis (TWEAK), binding to its receptor Fn14, has been suggested as an inducer of EPCs differentiation, viability and migration to the injury site in a model of myocardial infarction. Here, we have performed a proof-of-concept preclinical study in a rat model of ICH where we report that a 50 μg/kg dose of rat recombinant TWEAK (rTWEAK) promotes blood progenitor cells mobilization, mainly EPCs. As soon as 72 h post-injury, brain neovascularization, and, importantly, long-term hematoma reduction and improved functional recovery is reported. In contrast, a higher dose of 150 μg/kg blocked those beneficial outcomes. Therefore, a low dose of rTWEAK treatment promotes neovascularization and reduces brain damage in a rat model of ICH. Further clinical studies will be needed to demonstrate if rTWEAK could represent a new strategy to promote recovery following ICH. Full article

Endothelial progenitor cells (EPCs) play a crucial role in vascular repair, and their depletion has been involved in coronary artery disease (CAD) severity. This study examines the relationship between circulating EPC levels and CAD complexity, as quantified by the Syntax Score I. A total of 85 patients undergoing coronary angiography were enrolled, with EPCs quantified using flow cytometry. EPC proportion showed a significant inverse relationship with CAD severity, measured by Syntax Score I. Additionally, we investigated EPC levels in patients presenting with acute coronary syndrome (ACS) and found that EPC depletion was more pronounced in this group compared to non-ACS patients (median EPC count: 0.35 vs. 0.61, p = 0.027). These findings suggest that lower EPC levels are indicative of more severe CAD and ACS, reinforcing their potential as biomarkers for cardiovascular risk stratification, monitoring disease advancement, and identifying patients at risk of adverse events. Full article

Diabetes wound healing presents several significant challenges, which can complicate recovery and lead to severe consequences. Polyethylene glycol loxenatide (PEG-loxe), a long-acting glucagon-like peptide-1 receptor agonist (GLP-1RA), shows cardiovascular benefits, yet its role in diabetic wound healing remains unclear. Diabetic mice received PEG-loxe (0.03 mg/kg/week, i.p.) for three months. Glucose metabolism was evaluated using the insulin tolerance test (ITT) and oral glucose tolerance test (OGTT). Wound closure rates and angiogenesis-related proteins were analyzed. Serum proteomics was performed using the Olink assay to evaluate systemic inflammation. In vitro, human endothelial progenitor cells (EPCs) were exposed to high glucose and palmitic acid, with or without PEG-loxe treatment. EPC tube formation and migratory capacity were evaluated using the tube formation assay and migration assay, respectively. Levels of nitric oxide (NO) and phosphorylated endothelial nitric oxide synthase (p-eNOS) were quantified. Mitochondrial reactive oxygen species (ROS) production and mitochondrial membrane potential were assessed using MitoSOX and JC-1 staining. Cellular respiratory function was analyzed via the Seahorse XF assay. Autophagy was evaluated by examining the expression of autophagy-related proteins and the colocalization of mitochondria with lysosomes. PEG-loxe improved glucose tolerance, accelerated wound closure, and upregulated the hypoxia-inducible factor-1α/vascular endothelial growth factor/stromal cell-derived factor-1 axis (HIF-1α/VEGF/SDF-1) in diabetic mice. Serum proteomics revealed reduced pro-inflammatory markers and elevated anti-inflammatory IL-5. In vitro, PEG-loxe restored EPC function by enhancing NO production, reducing mitochondrial ROS, improving cellular respiratory function, and restoring autophagic flux. These findings suggest that PEG-loxe offers therapeutic benefits for diabetic wound healing by downregulating systemic inflammation, enhancing angiogenesis, and improving mitochondrial quality control in EPCs, highlighting GLP-1RAs as potential therapies for diabetic vascular complications. Full article

Cryopreservation is a widely used method for the long-term preservation of reproductive or somatic cells. It is known that this storage method may negatively affect cell viability, proliferation, differentiation, etc. However, there is a lack of information about whether cryostorage can alter the content of intracellular minerals. Therefore, we focused this study on the analysis of the mineral composition of living cells before and after long-term cold storage. Briefly, three different primary cell lines were established from rabbits as follows: endothelial progenitor cells from peripheral blood (EPCs), endothelial progenitor cells from bone marrow (BEPCs), and mesenchymal stem cells from adipose tissue (AT-MSCs), which were cultured until passage 3 prior to cryopreservation in liquid nitrogen. Samples from freshly cultured and frozen–thawed cells were mineralized and analyzed using inductively coupled plasma-optical emission spectroscopy (ICP-OES) for the content of minerals (macro: Ca, Na, K, and Mg, and micro: Zn, Fe, Cu, Al, Co, Mn, Sr, and Ni). After cryopreservation, we found significantly decreased content of K in frozen–thawed EPCs (p < 0.01) and BEPCs (p < 0.0001) and Ca in AT-MSCs (p < 0.05), while Na was increased in frozen–thawed BEPCs (p < 0.05). Concentrations of Fe and Al were reduced significantly in frozen–thawed EPCs (both p < 0.0001) and AT-MSCs (p < 0.001 and p < 0.0001, respectively). On the contrary, Fe and Al were elevated in frozen–thawed BEPCs (p < 0.0001 and p < 0.01, respectively) together with Ni (p < 0.0001). In addition, decreased Zn (p < 0.05) was observed in cryopreserved AT-MSCs. In conclusion, the ICP-OES technique might be used to analyze the basic elemental composition of animal cells in fresh or frozen–thawed conditions. Nevertheless, additional studies are needed to reveal the possible impact of cryopreservation on cell fate by changing the content of intracellular minerals. Full article

Circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) are promising markers of vascular damage and endothelial regeneration potential. We focused on the detection of CECs and EPCs using flow cytometry with regard to analytical challenges and its suitability for routine testing. As part of a clinical validation, CECs and EPCs were measured in blood samples from 83 subjects with type 1 diabetes (T1DM), evaluating an adjuvant intervention with two different antidiabetic drugs, empagliflozin (N = 28) and semaglutide (N = 29). Both groups receiving adjuvant therapy were compared with the insulin-only group (N = 26) at two time points: before the start of therapy and after 12 weeks of adjuvant therapy. All three groups were comparable regarding demographic characteristics and concomitant risk factors. Absolute and relative endothelial cell count at baseline were low and comparable to those of healthy individuals. In the group receiving empagliflozin or semaglutide, a significant increase in EPC was observed after 12 weeks of treatment. We demonstrated that EPCs have the potential to serve as markers for monitoring the efficacy of adjuvant therapy in T1DM patients. However, before their implementation in clinical practice, the flow cytometry protocol for CEC and EPC identification and quantification must be standardized. Full article

Background: Choroidal involution is a common feature of age-related ischemic retinopathies such as age-related macular degeneration (AMD). It is now well recognized that endothelial progenitor cells (EPCs) are essential to endothelial repair processes and in maintaining vascular integrity. However, the contribution of EPCs and the role of senescence in age-related choroidal vascular degeneration remain to be investigated. In this study, we compared the senescent phenotype of EPCs in the choroid and performed whole-genome profiling of EPCs derived from young versus old rats. Methods and Results: We isolated and compared the retinas of young (6-weeks-old) and old (16–18-month-old) rats. The thickness of the choroid and outer nuclear layer (ONL), along with local quantification of CD34+ EPCs, was performed. Compared to young rats, older rats displayed a significant reduction in choroidal and ONL thickness associated with markedly fewer choroid-localized EPCs; this was attested by lower expression of several EPC markers (CXCR4, CD34, CD117, CD133, and KLF-2). Choroid and choroid-localized EPCs displayed abundant senescence as revealed by increased β-gal and P53 expression and decreased Lamin-B1 (immunostaining and RT-qPCR). Concordantly, choroidal cells and EPCs isolated from older rats were unable to form vascular networks ex vivo. To better understand the potential mechanisms associated with the dysfunctional EPCs linked to age-related choroidal involution, we performed whole-genome profiling (mRNA and miRNA) of EPCs derived from old and young rats using next-generation sequencing (NGS); 802 genes were significantly modulated in old vs. young EPCs, corresponding to ~2% of total genes expressed. Using a bioinformatic algorithm, the KEGG pathways suggested that these genes participate in the modulation of several key signaling processes including inflammation, G protein-coupled receptors, and hematopoietic cell lineages. Moreover, we identified 13 miRNAs involved in the regulation of immune system processes, cell cycle arrest and senescence, which are significantly modulated in EPCs from old rats compared to young ones. Conclusions: Our results suggest that age-related choroidal involution is associated with fewer EPCs, albeit displaying a senescence-like phenotype. One would be tempted to propose that biological modification of native EPCs (such as with senolytic agents) could potentially provide a new strategy to preserve the vascular integrity of the aged choroid, and evade progression to degenerative maculopathies. Full article

Multiple myeloma (MM) is a plasma cell malignancy that resides within the bone marrow microenvironment, relying heavily on interactions with its cellular components. Among these, endothelial cells (ECs) play a pivotal role in MM progression and the development of therapeutic resistance. In this study, we analyzed publicly available single-cell RNA sequencing data to identify unique pathway activations distinguishing ECs from MM patients and healthy donors. We developed a novel protocol to isolate and culture endothelial progenitor cells (EPCs) and ECs directly from MM patient bone marrow, demonstrating their ability to promote myeloma cell proliferation. Validation studies confirmed that these MM-derived ECs exhibit angiogenic potential as well as the expression of characteristic endothelial lineage markers. These findings underscore the critical role of bone marrow ECs in the MM tumor microenvironment and highlight potential new therapeutic targets to disrupt MM progression. Full article

A comprehensive understanding of the cardio-spleen-bone marrow immune cell axis is essential for elucidating the alterations occurring during the pathogenesis of diabetes mellitus (DM). This study investigates the dynamics of immune cell kinetics in DM after myocardial infarction (MI) over time. MI was induced in diabetic and healthy control groups using C57BL/N6 mice, with sacrifices occurring at days 1, 3, 7, and 28 post-MI to collect heart, peripheral blood (PB), spleen, and bone marrow (BM) samples. Cell suspensions from each organ were isolated and analyzed via flow cytometry. Additionally, the endothelial progenitor cell-colony-forming assay (EPC-CFA) was performed using mononuclear cells derived from BM, PB, and the spleen. The results indicated that, despite normal production in BM and the spleen, CD45+ cells were lower in the PB of DM mice at days 1 to 3. Further analysis revealed a reduction in total and pro-inflammatory neutrophils (N1s) in PB at days 1 to 3 and in the spleen at days 3 to 7 in DM mice, suggesting that DM-induced alterations in splenic neutrophils fail to meet the demand in PB and ischemic tissues. Infiltrating macrophages (total, M1, M2) were reduced at day 3 in the DM-ischemic heart, with total and M1 (days 1–3) and M2 (days 3–7) macrophages being significantly decreased in DM-PB compared to controls, indicating impaired macrophage recruitment and polarization in DM. Myeloid dendritic cells (mDCs) in the heart were higher from days 1 to 7, which corresponded with the enhanced recruitment of CD8+ cells from days 1 to 28 in the DM-infarcted myocardium. Total CD4+ cells decreased in DM-PB at days 1 to 3, suggesting a delayed adaptive immune response to MI. B cells were reduced in PB at days 1 to 3, in myocardium at day 3, and in the spleen at day 7, indicating compromised mobilization from BM. EPC-CFA results showed a marked decrease in definitive EPC colonies in the spleen and BM from days 1 to 28 in DM mice compared to controls in vitro, highlighting that DM severely impairs EPC colony-forming activity by limiting the differentiation of EPCs from primitive to definitive forms. Taking together, this study underscores significant disruptions in the cardio-spleen-bone marrow immune cell axis following MI in DM, revealing delayed innate and adaptive immune responses along with impaired EPC differentiation. Full article

Background/Objectives. A Mediterranean diet (MD) has been associated with neuroprotective effects. We aimed to assess the MD’s association with stroke prognosis and the potential mediators involved. Methods. Seventy patients with acute anterior circulation ischemic stroke were included. Dietary patterns were evaluated using the MEDAS scale, a food-frequency questionnaire, and a 24 h recall. Circulating biomarkers including insulin resistance (HOMA index), adipokines (resistin, adiponectin, leptin), choline pathway metabolites (TMAO, betaine, choline), and endothelial progenitor cells (EPCs) were measured. Early neurological improvement (ENI) at 24 h, final infarct volume, and functional outcome at 3 months were assessed. Results. Adherence to MD and olive oil consumption were associated with a lower prevalence of diabetes and atherothrombotic stroke, and with lower levels of fasting glycemia, hemoglobinA1C, insulin resistance, and TMAO levels. Monounsaturated fatty acids and oleic acid consumption correlated with lower resistin levels, while olive oil consumption was significantly associated with EPC mobilization. Multivariate analysis showed that higher MD adherence was independently associated with ENI and good functional prognosis at 3 months. EPC mobilization, lower HOMA levels, and lower resistin levels were associated with ENI, a smaller infarct volume, and good functional outcome. Conclusions. MD was associated with better prognosis after ischemic stroke, potentially mediated by lower insulin resistance, increased EPC mobilization, and lower resistin levels, among other factors. Full article

Adult stem cell therapy via intramyocardial injection of autologous CD34+ stem cells has been shown to improve exercise capacity and reduce angina frequency and mortality in patients with refractory angina (RA). However, the cost of such therapy is a limitation to its adoption in clinical practice. Our goal was to determine whether the less costly, less invasive, and widely accessible, FDA-approved alternative treatment for RA patients, known as enhanced external counterpulsation (EECP), mobilizes endogenous CD34+ stem cells and whether such mobilization is associated with the clinical benefits seen with intramyocardial injection. We monitored changes in circulating levels of CD34+/CD133+ and CD34+/KDR+ cells in RA patients undergoing EECP therapy and in a comparator cohort of RA patients undergoing an exercise regimen known as cardiac rehabilitation. Changes in exercise capacity in both cohorts were monitored by measuring treadmill times (TT), double product (DP) scores, and Canadian Cardiovascular Society (CCS) angina scores between pre- and post-treatment treadmill stress tests. Circulating levels of CD34+/CD133+ cells increased in patients undergoing EECP and were significant (β = −2.38, p = 0.012) predictors of improved exercise capacity in these patients. CD34+/CD133+ cells isolated from RA patients could differentiate into endothelial cells, and their numbers increased during EECP therapy. Our results support the hypothesis that mobilized CD34+/CD133+ cells repair vascular damage and increase collateral circulation in RA patients. They further support clinical interventions that can mobilize adult CD34+ stem cells as therapy for patients with RA and other vascular diseases. Full article

Congenital heart disease (CHD) can be complicated by pulmonary arterial hypertension (PAH). Cardiopulmonary bypass (CPB) for corrective surgery may cause endothelial dysfunction, involving endothelin-1 (ET-1), circulating endothelial cells (CECs), and endothelial progenitor cells (EPCs). These markers can gauge disease severity, but their levels in children’s peripheral blood still lack consensus for prognostic value. The aim of our study was to investigate changes in ET-1, cytokines, and the absolute numbers (Ɲ) of CECs and EPCs in children 24 h before and 48 h after CPB surgery to identify high-risk patients of complications. A cohort of 56 children was included: 41 cases with CHD-PAH (22 with high pulmonary flow and 19 with low pulmonary flow) and 15 control cases. We observed that Ɲ-CECs increased in both CHD groups and that Ɲ-EPCs decreased in the immediate post-surgical period, and there was a strong negative correlation between ET-1 and CEC before surgery, along with significant changes in ET-1, IL8, IL6, and CEC levels. Our findings support the understanding of endothelial cell precursors’ role in endogenous repair and contribute to knowledge about endothelial dysfunction in CHD. Full article

Endothelial progenitor cells (EPCs) are circulating cells of various origins that possess the capacity for renewing and regenerating the endothelial lining of blood vessels. During physical activity, in response to factors such as hypoxia, changes in osmotic pressure, and mechanical forces, endothelial cells undergo intense physiological stress that results in endothelial damage. Circulating EPCs participate in blood vessel repair and vascular healing mainly through paracrine signalling. Furthermore, physical activity may play an important role in mobilising this important cell population. In this narrative review, we summarise the current knowledge on the biology of EPCs, including their characteristics, assessment, and mobilisation in response to both chronic and acute physical activity in healthy individuals. Full article

Endothelial progenitor cells (EPCs) play a critical role in cardiovascular regeneration. Enhancement of their native properties would be highly beneficial to ensuring the proper functioning of the cardiovascular system. As androgens have a positive effect on the cardiovascular system, we hypothesized that dihydrotestosterone (DHT) could also influence EPC-mediated repair processes. To evaluate this hypothesis, we investigated the effects of DHT on cultured human EPCs’ proliferation, viability, morphology, migration, angiogenesis, gene and protein expression, and ability to integrate into cardiac tissue. The results showed that DHT at different concentrations had no cytotoxic effect on EPCs, significantly enhanced the cell proliferation and viability and induces fast, androgen-receptor-dependent formation of capillary-like structures. DHT treatment of EPCs regulated gene expression of androgen receptors and the genes and proteins involved in cell migration and angiogenesis. Importantly, DHT stimulation promoted EPC migration and the cells’ ability to adhere and integrate into murine cardiac slices, suggesting it has a role in promoting tissue regeneration. Mass spectrometry analysis further highlighted the impact of DHT on EPCs’ functioning. In conclusion, DHT increases the proliferation, migration, and androgen-receptor-dependent angiogenesis of EPCs; enhances the cells’ secretion of key factors involved in angiogenesis; and significantly potentiates cellular integration into heart tissue. The data offer support for potential therapeutic applications of DHT in cardiovascular regeneration and repair processes. Full article