Characterization of Endothelial Progenitor Cell: Past, Present, and Future

Endoscopic nasal delivery of engineered endothelial progenitor cell-derived exosomes improves angiogenesis and neurological deficits in rats with intracerebral hemorrhage

Intracerebral hemorrhage (ICH) remains a life-threatening condition due to its high mortality and limited treatment options. This study explores a novel therapeutic strategy using engineered exosomes derived from endothelial progenitor cells (EPC-EXOs) to improve ICH outcomes. EPC-EXOs were modified with a CD47-enriched red blood cell membrane via co-extrusion to enhance their anti-phagocytic properties, thereby reducing degradation by activated microglia after ICH. A minimally invasive endoscopic-guided delivery system was developed to facilitate the targeted intranasal administration of these engineered EPC-EXOs (m-Oe-EXOs), allowing direct entry into brain tissue. We confirmed m-Oe-EXOs' high retention and effective distribution in the brain. Functional analysis demonstrated that EPC-EXOs significantly promoted the proliferation, migration, and angiogenesis of brain microvascular endothelial cells (BMECs), with proteomic analysis identifying HSP90 as a key protein activating the Akt pathway in BMECs. In vivo, m-Oe-EXOs demonstrated therapeutic efficacy by improving blood-brain barrier integrity, reducing hematoma volume, and enhancing neurological recovery in ICH rats. Collectively, our findings highlight the potential of minimally invasive, endoscopic-guided delivery of m-Oe-EXOs as an innovative approach for ICH treatment, providing new insights into targeted, exosomes-based regenerative therapies.

Physically engineered extracellular vesicles targeted delivering miR-21-5p to promote renoprotection after renal ischemia-reperfusion injury

Acute kidney injury (AKI) resulting from ischemia-reperfusion injury (IRI) is a common challenge in various clinical practices, yet effective therapies remain elusive. Endothelial injury plays a crucial role in the pathogenesis of renal IRI. Endothelial progenitor cells (EPCs) derived extracellular vesicles (EVs) hold promise as cell-free therapies for treating renal IRI; however, their efficacy is limited by low delivery efficiency. In this study, we developed neutrophils (NEs) membrane-modified EVs (N-EVs) by exploiting the natural properties of NEs to target damaged endothelium. N-EVs inherited the characteristic membrane proteins of NEs along with the biological functions of EPCs-EVs. Results from in vitro and in vivo experiments demonstrated that N-EVs significantly enhanced the targeting efficiency of EVs towards IRI kidneys via P-selectin glycoprotein ligand-1 (PSGL-1). Moreover, N-EVs effectively promoted the proliferation, migration, and tube-formation abilities of injured endothelial cells (ECs) and contributed to overall renal function improvement in IRI kidneys through targeted delivery of miR-21-5p. Additionally, N-EVs could restore damaged endothelial integrity, reduce cytokine release, and inhibit leukocyte infiltration, hence alleviating renal inflammation. In conclusion, our accessible engineering approach represents a promising strategy for treating renal IRI. Furthermore, this membrane hybrid modification can be tailored and optimized for broader applications in treating other diseases.

Pathogenic Mechanisms of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)-Associated Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third leading cause of cancer deaths worldwide. The etiology of HCC has now dramatically changed from viral hepatitis to metabolic dysfunction-associated steatotic liver disease (MASLD). The main pathogenesis of MASLD-related HCC is the hepatic lipid accumulation of hepatocytes, which causes chronic inflammation and the subsequent progression of hepatic fibrosis. Chronic hepatic inflammation generates oxidative stress and DNA damage in hepatocytes, which contribute to genomic instability, resulting in the development of HCC. Several metabolic and molecular pathways are also linked to chronic inflammation and HCC in MASLD. In particular, the MAPK and PI3K-Akt-mTOR pathways are upregulated in MASLD, promoting the survival and proliferation of HCC cells. In addition, MASLD has been reported to enhance the development of HCC in patients with chronic viral hepatitis infection. Although there is no approved medication for MASLD besides resmetirom in the USA, there are some preventive strategies for the onset and progression of HCC. Sodium-glucose cotransporter-2 (SGLT2) inhibitor, a class of medications, has been reported to exert anti-tumor effects on HCC by regulating metabolic reprogramming. Moreover, CD34-positive cell transplantation improves hepatic fibrosis by promoting intrahepatic angiogenesis and supplying various growth factors. Furthermore, exercise improves MASLD through an increase in energy consumption as well as changes in chemokines and myokines. In this review, we summarize the recent progress made in the pathogenic mechanisms of MASLD-associated HCC. Furthermore, we introduced new therapeutic strategies for preventing the development of HCC based on the pathogenesis of MASLD.

Unleashing the potential of extracellular vesicles for ulcerative colitis and Crohn's disease therapy

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Recent advances in surface functionalization of cardiovascular stents

Cardiovascular diseases (CVD) are the leading global threat to human health. The clinical application of vascular stents improved the survival rates and quality of life for patients with cardiovascular diseases. However, despite the benefits stents bring to patients, there are still notable complications such as thrombosis and in-stent restenosis (ISR). Surface modification techniques represent an effective strategy to enhance the clinical efficacy of vascular stents and reduce complications. This paper reviews the development strategies of vascular stents based on surface functional coating technologies aimed at addressing the limitations in clinical application, including the inhibition of intimal hyperplasia, promotion of re-endothelialization. These strategies have improved endothelial repair and inhibited vascular remodeling, thereby promoting vascular healing post-stent implantation. However, the pathological microenvironment of target vessels and the lipid plaques are key pathological factors in the development of atherosclerosis (AS) and impaired vascular repair after percutaneous coronary intervention (PCI). Therefore, restoring normal physiological environment and removing the plaques are also treatment focuses after PCI for promoting vascular repair. Unfortunately, research in this area is limited. This paper reviews the advancements in vascular stents based on surface engineering technologies over the past decade, providing guidance for the development of stents.

Stem Cell-Based Therapies via Different Administration Route for Stroke: A Meta-analysis of Comparative Studies

Stroke, a neurological condition from compromised cerebral blood perfusion, remains a major global cause of mortality and disability. Conventional therapies like tissue plasminogen activator are limited by narrow therapeutic windows and potential adverse effects, highlighting the urgency for novel treatments. Stem cell-based therapies, with their neuroprotective and regenerative properties, present a promising yet highly diverse alternative. By conducting literature search and data extraction from the PubMed, Embase, and Cochrane databases, this meta-analysis assessed the clinical efficacy and safety of stem cell-based therapies administered via intravenous (IV) and non-IV routes in 17 studies with stroke patients. Primary outcomes included the National Institute of Health Stroke Scale (NIHSS), Barthel Index (BI), and modified Rankin Scale (mRS), while secondary outcomes included mortality and adverse events. Results demonstrated significant improvements in NIHSS, BI, and mRS scores, particularly in non-IV groups within 6- and 12-month follow-ups, suggesting delayed but enhanced therapeutic efficacy. Mortality was reduced in both IV and non-IV groups, indicating treatment safety. Adverse events, categorized into neurological and systemic complications, showed no significant differences between intervention and control groups, further emphasizing the safety of stem cell therapies. Non-IV routes showed more long-term benefits, potentially due to enhanced cell delivery and integration. These findings demonstrate the potential of stem cell therapies to improve functional recovery and survival in stroke patients, regardless of administration route. However, the delayed response underscores the need for extended follow-up in clinical applications. Further research is required to standardize treatment protocols, optimize cell types and doses, and address patient-specific factors to integrate stem cell therapies into routine clinical practice.

Stem cells and bio scaffolds for the treatment of cardiovascular diseases: new insights

Mortality and morbidity from cardiovascular diseases are common worldwide. In order to improve survival and quality of life for this patient population, extensive efforts are being made to establish effective therapeutic modalities. New treatment options are needed, it seems. In addition to treating cardiovascular diseases, cell therapy is one of the most promising medical platforms. One of the most effective therapeutic approaches in this area is stem cell therapy. In stem cell biology, multipotent stem cells and pluripotent stem cells are divided into two types. There is evidence that stem cell therapy could be used as a therapeutic approach for cardiovascular diseases based on multiple lines of evidence. The effectiveness of stem cell therapies in humans has been studied in several clinical trials. In spite of the challenges associated with stem cell therapy, it appears that resolving them may lead to stem cells being used in cardiovascular disease patients. This may be an effective therapeutic approach. By mounting these stem cells on biological scaffolds, their effect can be enhanced.

Cardioimmunology in Health and Diseases: Impairment of the Cardio-Spleno-Bone Marrow Axis Following Myocardial Infarction in Diabetes Mellitus

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.

Expression of Myeloperoxidase in Patient-Derived Endothelial Colony-Forming Cells-Associations with Coronary Artery Disease and Mitochondrial Function

BACKGROUND AND AIMS

Myeloperoxidase (MPO) plays a critical role in the innate immune response and has been suggested to be a surrogate marker of oxidative stress and inflammation, with elevated levels implicated in cardiovascular diseases, such as atherosclerosis and heart failure, as well as in conditions like rheumatoid arthritis and cancer. While MPO is well-known in leukocytes, its expression and function in human endothelial cells remain unclear. This study investigates MPO expression in patient-derived endothelial colony-forming cells (ECFCs) and its potential association with CAD and mitochondrial function.

METHODS

ECFCs were cultured from the peripheral blood of 93 BioHEART-CT patients. MPO expression and associated functions were examined using qRT-PCR, immunochemistry, flow cytometry, and MPO activity assays. CAD presence was defined using CT coronary angiography (CACS > 0).

RESULTS

We report MPO presence in patient-derived ECFCs for the first time. MPO protein expression occurred in 70.7% of samples (n = 41) which had nuclear co-localisation, an atypical observation given its conventional localisation in the granules of neutrophils and monocytes. This suggests potential alternative roles for MPO in nuclear processes. MPO mRNA expression was detected in 66.23% of samples (n = 77). CAD patients had a lower proportion of MPO-positive ECFCs compared to non-CAD controls (57.45% vs. 80%, p = 0.04), a difference that persisted in the statin-naïve sub-cohort (53.85% vs. 84.62%, p = 0.02). Non-CAD patients with MPO expression showed upregulated mitochondrial-antioxidant genes (AIFM2, TXNRD1, CAT, PRDX3, PRDX6). In contrast, CAD patients with MPO gene expression had heightened mROS production and mitochondrial mass and decreased mitochondrial function compared to that of CAD patients without MPO gene expression.

CONCLUSIONS

MPO is present in the nucleus of ECFCs. In non-CAD ECFCs, MPO expression is linked to upregulated mitochondrial-antioxidant genes, whereas in CAD ECFCs, it is associated with greater mitochondrial dysfunction.

The vascular phenotype of BPD: new basic science insights-new precision medicine approaches

Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth. Up to 1/3 of children with BPD develop pulmonary hypertension (PH). PH increases mortality, the risk of adverse neurodevelopmental outcome and lacks effective treatment. Current vasodilator therapies address symptoms, but not the underlying arrested vascular development. Recent insights into placental biology and novel technological advances enabling the study of normal and impaired lung development at the single cell level support the concept of a vascular phenotype of BPD. Dysregulation of growth factor pathways results in depletion and dysfunction of putative distal pulmonary endothelial progenitor cells including Cap1, Cap2, and endothelial colony-forming cells (ECFCs), a subset of vascular progenitor cells with self-renewal and de novo angiogenic capacity. Preclinical data demonstrate effectiveness of ECFCs and ECFC-derived particles including extracellular vesicles (EVs) in promoting lung vascular growth and reversing PH, but the mechanism is unknown. The lack of engraftment suggests a paracrine mode of action mediated by EVs that contain miRNA. Aberrant miRNA signaling contributes to arrested pulmonary vascular development, hence using EV- and miRNA-based therapies is a promising strategy to prevent the development of BPD-PH. More needs to be learned about disrupted pathways, timing of intervention, and mode of delivery. IMPACT: Single-cell RNA sequencing studies provide new in-depth view of developmental endothelial depletion underlying BPD-PH. Aberrant miRNA expression is a major cause of arrested pulmonary development. EV- and miRNA-based therapies are very promising therapeutic strategies to improve prognosis in BPD-PH.

Transdermal Nicotine Patch Increases the Number and Function of Endothelial Progenitor Cells in Young Healthy Nonsmokers without Adverse Hemodynamic Effects

Transdermal nicotine patches (TNPs), administering nicotine into the bloodstream through skin, have been widely used as nicotine replacement therapy, and exposure to nicotine can be detected by measurement of plasma cotinine concentration. In animal studies, nicotine treatment could increase the number of endothelial progenitor cells (EPCs), but the effect of TNPs on circulating EPCs and their activity in humans remained unclear. This study aimed to explore the influence of TNPs on circulating EPCs with surface markers of CD34, CD133, and/or KDR, and colony-forming function plus migration activity of early EPCs derived from cultured peripheral blood mononuclear cells before and after TNP treatments in young healthy nonsmokers. In parallel, pulse wave analysis (PWA) was applied to evaluate the vascular effect of TNP treatments. Twenty-one participants (25.8 ± 3.6 years old, 10 males) used TNP (nicotine: 4.2 mg/day) for 7 consecutive days. During the treatment, the CD34+ EPCs progressively increased in number. In addition, the number of EPCs positive for CD34/KDR, CD133, and CD34/CD133 were also increased on day 7 of the treatment. Furthermore, the early EPC colony-forming function and migration activity were increased with the plasma cotinine level positively correlating with change in colony-forming unit number. PWA analyses on day 7, compared with pretreatment, did not show significant change except diastolic pressure time index, which was prolonged and implied potential vascular benefit. In conclusion, 7-day TNP treatments could be a practical strategy to enhance angiogenesis of circulating EPCs to alleviate tissue ischemia without any hemodynamic concern.

Endothelial Progenitor Cells: A Review of Molecular Mechanisms in the Pathogenesis and Endovascular Treatment of Intracranial Aneurysms

This comprehensive review explores the multifaceted role of endothelial progenitor cells (EPCs) in vascular diseases, focusing on their involvement in the pathogenesis and their contributions to enhancing the efficacy of endovascular treatments for intracranial aneurysms (IAs). Initially discovered as CD34+ bone marrow-derived cells implicated in angiogenesis, EPCs have been linked to vascular repair, vasculogenesis, and angiogenic microenvironments. The origin and differentiation of EPCs have been subject to debate, challenging the conventional notion of bone marrow origin. Quantification methods, including CD34+ , CD133+ , and various assays, reveal the influence of factors, like age, gender, and comorbidities on EPC levels. Cellular mechanisms highlight the interplay between bone marrow and angiogenic microenvironments, involving growth factors, matrix metalloproteinases, and signaling pathways, such as phosphatidylinositol-3-kinase (PI3K) and mitogen-activated protein kinase (MAPK). In the context of the pathogenesis of IAs, EPCs play a role in maintaining vascular integrity by replacing injured and dysfunctional endothelial cells. Recent research has also suggested the therapeutic potential of EPCs after coil embolization and flow diversion, and this has led the development of device surface modifications aimed to enhance endothelialization. The comprehensive insights underscore the importance of further research on EPCs as both therapeutic targets and biomarkers in IAs.

HOXD9 regulated mitophagy to promote endothelial progenitor cells angiogenesis and deep vein thrombosis recanalization and resolution

BACKGROUND

Deep vein thrombosis (DVT) is a common vascular surgical disease caused by the coagulation of blood in the deep veins, and predominantly occur in the lower limbs. Endothelial progenitor cells (EPCs) are multi-functional stem cells, which are precursors of vascular endothelial cells. EPCs have gradually evolved into a promising treatment strategy for promoting deep vein thrombus dissolution and recanalization through the stimulation of various physical and chemical factors.

METHODS

In this study, we utilized a mouse DVT model and performed several experiments including qRT-PCR, Western blot, tube formation, wound healing, Transwell assay, immunofluorescence, flow cytometry analysis, and immunoprecipitation to investigate the role of HOXD9 in the function of EPCs cells. The therapeutic effect of EPCs overexpressing HOXD9 on the DVT model and its mechanism were also explored.

RESULTS

Overexpression of HOXD9 significantly enhanced the angiogenesis and migration abilities of EPCs, while inhibiting cell apoptosis. Additionally, results indicated that HOXD9 specifically targeted the HRD1 promoter region and regulated the downstream PINK1-mediated mitophagy. Interestingly, intravenous injection of EPCs overexpressing HOXD9 into mice promoted thrombus dissolution and recanalization, significantly decreasing venous thrombosis.

CONCLUSIONS

The findings of this study reveal that HOXD9 plays a pivotal role in stimulating vascular formation in endothelial progenitor cells, indicating its potential as a therapeutic target for DVT management.

Endothelial progenitor cell-derived extracellular vesicles: the world of potential prospects for the treatment of cardiovascular diseases

Cardiovascular diseases (CVDs) have emerged as a predominant threat to human health, surpassing the incidence and mortality rates of neoplastic diseases. Extracellular vesicles (EVs) serve as vital mediators in intercellular communication and material exchange. Endothelial progenitor cells (EPCs), recognized as precursors of vascular endothelial cells (ECs), have garnered considerable attention in recent years due to the potential therapeutic value of their derived extracellular vesicles (EPC-EVs) in the context of CVDs. This comprehensive review systematically explores the origins, characteristics, and functions of EPCs, alongside the classification, properties, biogenesis, and extraction techniques of EVs, with particular emphasis on their protective roles in CVDs. Additionally, we delve into the essential bioactive components of EPC-EVs, including microRNAs, long non-coding RNAs, and proteins, analyzing their beneficial effects in promoting angiogenesis, anti-inflammatory and anti-oxidant activities, anti-fibrosis, anti-apoptosis, and myocardial regeneration. Furthermore, this review comprehensively investigates the therapeutic potential of EPC-EVs across various CVDs, encompassing acute myocardial infarction, myocardial ischemia-reperfusion injury, atherosclerosis, non-ischemic cardiomyopathies, and diabetic cardiovascular disease. Lastly, we summarize the potential challenges associated with the clinical application of EPC-EVs and outline future directions, aiming to offer a valuable resource for both theoretical insights and practical applications of EPC-EVs in managing CVDs.

Responses of Endothelial Progenitor Cells to Chronic and Acute Physical Activity in Healthy Individuals

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.

Recent trends in bone tissue engineering: a review of materials, methods, and structures

Bone tissue engineering (BTE) provides the treatment possibility for segmental long bone defects that are currently an orthopedic dilemma. This review explains different strategies, from biological, material, and preparation points of view, such as using different stem cells, ceramics, and metals, and their corresponding properties for BTE applications. In addition, factors such as porosity, surface chemistry, hydrophilicity and degradation behavior that affect scaffold success are introduced. Besides, the most widely used production methods that result in porous materials are discussed. Gene delivery and secretome-based therapies are also introduced as a new generation of therapies. This review outlines the positive results and important limitations remaining in the clinical application of novel BTE materials and methods for segmental defects.

Emerging Strategies in Mesenchymal Stem Cell-Based Cardiovascular Therapeutics

Cardiovascular diseases continue to challenge global health, demanding innovative therapeutic solutions. This review delves into the transformative role of mesenchymal stem cells (MSCs) in advancing cardiovascular therapeutics. Beginning with a historical perspective, we trace the development of stem cell research related to cardiovascular diseases, highlighting foundational therapeutic approaches and the evolution of cell-based treatments. Recognizing the inherent challenges of MSC-based cardiovascular therapeutics, which range from understanding the pro-reparative activity of MSCs to tailoring patient-specific treatments, we emphasize the need to refine the pro-regenerative capacity of these cells. Crucially, our focus then shifts to the strategies of the fourth generation of cell-based therapies: leveraging the secretomic prowess of MSCs, particularly the role of extracellular vesicles; integrating biocompatible scaffolds and artificial sheets to amplify MSCs' potential; adopting three-dimensional ex vivo propagation tailored to specific tissue niches; harnessing the promise of genetic modifications for targeted tissue repair; and institutionalizing good manufacturing practice protocols to ensure therapeutic safety and efficacy. We conclude with reflections on these advancements, envisaging a future landscape redefined by MSCs in cardiovascular regeneration. This review offers both a consolidation of our current understanding and a view toward imminent therapeutic horizons.

Biomaterials-Based Strategies to Enhance Angiogenesis in Diabetic Wound Healing

Amidst the present healthcare issues, diabetes is unique as an emerging class of affliction with chronicity in a majority of the population. To check and control its effects, there have been huge turnover and constant development of management strategies, and though a bigger part of the health care area is involved in achieving its control and the related issues such as the effect of diabetes on wound healing and care and many of the works have reached certain successful outcomes, still there is a huge lack in managing it, with maximum effect yet to be attained. Studying pathophysiology and involvement of various treatment options, such as tissue engineering, application of hydrogels, drug delivery methods, and enhancing angiogenesis, are at constantly developing stages either direct or indirect. In this review, we have gathered a wide field of information and different new therapeutic methods and targets for the scientific community, paving the way toward more settled ideas and research advances to cure diabetic wounds and manage their outcomes.

Endothelial progenitor cells in pregnancy-related diseases

Placental neovascularization plays a crucial role in fetomaternal circulation throughout pregnancy and is dysregulated in several pregnancy-related diseases, including preeclampsia, gestational diabetes mellitus, and fetal growth restriction. Endothelial progenitor cells (EPCs) are a heterogeneous population of cells that differentiate into mature endothelial cells, which influence vascular homeostasis, neovascularization, and endothelial repair. Since their discovery in 1997 by Asahara et al., the role of EPCs in vascular biology has garnered a lot of interest. However, although pregnancy-related conditions are associated with changes in the number and function of EPCs, the reported findings are conflicting. This review discusses the discovery, isolation, and classification of EPCs and highlights discrepancies between current studies. Overviews of how various diseases affect the numbers and functions of EPCs, the role of EPCs as biomarkers of pregnancy disorders, and the potential therapeutic applications involving EPCs are also provided.

The Impact of Modern Anti-Diabetic Treatment on Endothelial Progenitor Cells

Diabetes is one of the leading chronic diseases globally with a significant impact on mortality. This condition is associated with chronic microvascular and macrovascular complications caused by vascular damage. Recently, endothelial progenitor cells (EPCs) raised interest due to their regenerative properties. EPCs are mononuclear cells that are derived from different tissues. Circulating EPCs contribute to regenerating the vessel's intima and restoring vascular function. The ability of EPCs to repair vascular damage depends on their number and functionality. Diabetic patients have a decreased circulating EPC count and impaired EPC function. This may at least partially explain the increased risk of diabetic complications, including the increased cardiovascular risk in these patients. Recent studies have confirmed that many currently available drugs with proven cardiovascular benefits have beneficial effects on EPC count and function. Among these drugs are also medications used to treat different types of diabetes. This manuscript aims to critically review currently available evidence about the ways anti-diabetic treatment affects EPC biology and to provide a broader context considering cardiovascular complications. The therapies that will be discussed include lifestyle adjustments, metformin, sulphonylureas, gut glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase 4 inhibitors, glucagon-like peptide 1 receptor analogs, sodium-glucose transporter 2 inhibitors, and insulin.

Endothelial progenitor cells as biomarkers of diabetes-related cardiovascular complications

Diabetes mellitus (DM) constitutes a chronic metabolic disease characterized by elevated levels of blood glucose which can also lead to the so-called diabetic vascular complications (DVCs), responsible for most of the morbidity, hospitalizations and death registered in these patients. Currently, different approaches to prevent or reduce DM and its DVCs have focused on reducing blood sugar levels, cholesterol management or even changes in lifestyle habits. However, even the strictest glycaemic control strategies are not always sufficient to prevent the development of DVCs, which reflects the need to identify reliable biomarkers capable of predicting further vascular complications in diabetic patients. Endothelial progenitor cells (EPCs), widely known for their potential applications in cell therapy due to their regenerative properties, may be used as differential markers in DVCs, considering that the number and functionality of these cells are affected under the pathological environments related to DM. Besides, drugs commonly used with DM patients may influence the level or behaviour of EPCs as a pleiotropic effect that could finally be decisive in the prognosis of the disease. In the current review, we have analysed the relationship between diabetes and DVCs, focusing on the potential use of EPCs as biomarkers of diabetes progression towards the development of major vascular complications. Moreover, the effects of different drugs on the number and function of EPCs have been also addressed.

Impaired Angiogenic Function of Fetal Endothelial Progenitor Cells via PCDH10 in Gestational Diabetes Mellitus

Maternal hyperglycemia, induced by gestational diabetes mellitus (GDM), has detrimental effects on fetal vascular development, ultimately increasing the risk of cardiovascular diseases in offspring. The potential underlying mechanisms through which these complications occur are due to functional impairment and epigenetic changes in fetal endothelial progenitor cells (EPCs), which remain less defined. We confirm that intrauterine hyperglycemia leads to the impaired angiogenic function of fetal EPCs, as observed through functional assays of outgrowth endothelial cells (OECs) derived from fetal EPCs of GDM pregnancies (GDM-EPCs). Notably, PCDH10 expression is increased in OECs derived from GDM-EPCs, which is associated with the inhibition of angiogenic function in fetal EPCs. Additionally, increased PCDH10 expression is correlated with the hypomethylation of the PCDH10 promoter. Our findings demonstrate that in utero exposure to GDM can induce angiogenic dysfunction in fetal EPCs through altered gene expression and epigenetic changes, consequently increasing the susceptibility to cardiovascular diseases in the offspring of GDM mothers.

Results of an international survey about methods used to isolate human endothelial colony-forming cells: guidance from the SSC on Vascular Biology of the ISTH

BACKGROUND

Assessment of endothelial colony-forming cell (ECFC) number and vasculogenic properties is crucial for exploring vascular diseases and regeneration strategies. A previous survey of the Scientific and Standardization Committee on Vascular Biology of the International Society on Thrombosis and Haemostasis clarified key methodological points but highlighted a lack of standardization associated with ECFC culture.

OBJECTIVES

The aim of this study was to provide expert consensus guidance on ECFC isolation and culture.

METHODS

We surveyed 21 experts from 10 different countries using a questionnaire proposed during the 2019 International Society on Thrombosis and Haemostasis Congress in Melbourne (Australia) to attain a consensus on ECFC isolation and culture.

RESULTS

We report here the consolidated results of the questionnaire. There was agreement on several general statements, mainly the technical aspects of ECFC isolation and cell culture. In contrast, on the points concerning the definition of a colony of ECFCs, the quantification of ECFCs, and the estimation of their age (in days or number of passages), the expert opinions were widely dispersed.

CONCLUSION

Our survey clearly indicates an unmet need for rigorous standardization, multicenter comparison of results, and validation of ECFC isolation and culture procedures for clinical laboratory practice and robustness of results. To this end, we propose a standardized protocol for the isolation and expansion of ECFCs from umbilical cord and adult peripheral blood.

Combination human umbilical cord perivascular and endothelial colony forming cell therapy for ischemic cardiac injury

Cell-based therapeutics are promising interventions to repair ischemic cardiac tissue. However, no single cell type has yet been found to be both specialized and versatile enough to heal the heart. The synergistic effects of two regenerative cell types including endothelial colony forming cells (ECFC) and first-trimester human umbilical cord perivascular cells (FTM HUCPVC) with endothelial cell and pericyte properties respectively, on angiogenic and regenerative properties were tested in a rat model of myocardial infarction (MI), in vitro tube formation and Matrigel plug assay. The combination of FTM HUCPVCs and ECFCs synergistically reduced fibrosis and cardiomyocyte apoptosis, while promoting favorable cardiac remodeling and contractility. These effects were in part mediated by ANGPT2, PDGF-β, and VEGF-C. PDGF-β signaling-dependent synergistic effects on angiogenesis were also observed in vitro and in vivo. FTM HUCPVCs and ECFCs represent a cell combination therapy for promoting and sustaining vascularization following ischemic cardiac injury.

StemRegenin-1 Attenuates Endothelial Progenitor Cell Senescence by Regulating the AhR Pathway-Mediated CYP1A1 and ROS Generation

Endothelial progenitor cell (EPC)-based stem cell therapy is a promising therapeutic strategy for vascular diseases. However, continuous in vitro expansion for clinical studies induces the loss of EPC functionality due to aging. In this study, we investigated the effects of StemRegenin-1 (SR-1), an antagonist of aryl hydrocarbon receptor (AhR), on replicative senescence in EPCs. We found that SR-1 maintained the expression of EPC surface markers, including stem cell markers, such as CD34, c-Kit, and CXCR4. Moreover, SR-1 long-term-treated EPCs preserved their characteristics. Subsequently, we demonstrated that SR-1 showed that aging phenotypes were reduced through senescence-associated phenotypes, such as β-galactosidase activity, SMP30, p21, p53, and senescence-associated secretory phenotype (SASP). SR-1 treatment also increased the proliferation, migration, and tube-forming capacity of senescent EPCs. SR-1 inhibited the AhR-mediated cytochrome P450 (CYP)1A1 expression, reactive-oxygen species (ROS) production, and DNA damage under oxidative stress conditions in EPCs. Furthermore, as a result of CYP1A1-induced ROS inhibition, it was found that accumulated intracellular ROS were decreased in senescent EPCs. Finally, an in vivo Matrigel plug assay demonstrated drastically enhanced blood vessel formation via SR-1-treated EPCs. In summary, our results suggest that SR-1 contributes to the protection of EPCs against cellular senescence.

Therapeutic application of regeneration-associated cells: a novel source of regenerative medicine

Chronic diseases with comorbidities or associated risk factors may impair the function of regenerative cells and the regenerative microenvironment. Following this consideration, the vasculogenic conditioning culture (VCC) method was developed to boost the regenerative microenvironment to achieve regeneration-associated cells (RACs), which contain vasculogenic endothelial progenitor cells (EPCs) and anti-inflammatory/anti-immunity cells. Preclinical and clinical studies demonstrate that RAC transplantation is a safe and convenient cell population for promoting ischemic tissue recovery based on its strong vasculogenicity and functionality. The outputs of the scientific reports reviewed in the present study shed light on the fact that RAC transplantation is efficient in curing various diseases. Here, we compactly highlight the universal features of RACs and the latest progress in their translation toward clinics.

Immunomagnetic Delivery of Adipose-Derived Endothelial Progenitor Cells for the Repair of Renal Ischemia-Reperfusion Injury in a Rat Model

Renal ischemia-reperfusion injury (IRI) is a significant cause of acute kidney injury (AKI) and usually brings severe public health consequences. Adipose-derived endothelial progenitor cell (AdEPCs) transplantation is beneficial for AKI but suffers from low delivery efficiency. This study was conducted to explore the protective effects of magnetically delivered AdEPCs on the repair of renal IRI. Two types of magnetic delivery methods, namely the endocytosis magnetization (EM) method and the immunomagnetic (IM) method were fabricated using PEG@Fe₃O₄ and CD133@Fe₃O₄, and their cytotoxicities in AdEPCs were assessed. In the renal IRI rat model, magnetic AdEPCs were injected via the tail vein and a magnet was placed beside the injured kidney for magnetic guidance. The distribution of transplanted AdEPCs, renal function, and tubular damage were evaluated. Our results suggested that CD133@Fe₃O₄ had the minimum negative effects on the proliferation, apoptosis, angiogenesis, and migration of AdEPCs compared with PEG@Fe₃O₄. Renal magnetic guidance could significantly enhance the transplantation efficiency and the therapeutic outcomes of AdEPCs-PEG@Fe₃O₄ and AdEPCs-CD133@Fe₃O₄ in the injured kidneys. However, under renal magnetic guidance, AdEPCs-CD133@Fe₃O₄ had stronger therapeutic effects than PEG@Fe₃O₄ after renal IRI. The immunomagnetic delivery of AdEPCs with CD133@Fe₃O₄ could be a promising therapeutic strategy for renal IRI.

CD34 positive cells as endothelial progenitor cells in biology and medicine

CD34 is a cell surface antigen expressed in numerous stem/progenitor cells including hematopoietic stem cells (HSCs) and endothelial progenitor cells (EPCs), which are known to be rich sources of EPCs. Therefore, regenerative therapy using CD34⁺ cells has attracted interest for application in patients with various vascular, ischemic, and inflammatory diseases. CD34⁺ cells have recently been reported to improve therapeutic angiogenesis in a variety of diseases. Mechanistically, CD34⁺ cells are involved in both direct incorporation into the expanding vasculature and paracrine activity through angiogenesis, anti-inflammatory, immunomodulatory, and anti-apoptosis/fibrosis roles, which support the developing microvasculature. Preclinical, pilot, and clinical trials have well documented a track record of safety, practicality, and validity of CD34⁺ cell therapy in various diseases. However, the clinical application of CD34⁺ cell therapy has triggered scientific debates and controversies in last decade. This review covers all preexisting scientific literature and prepares an overview of the comprehensive biology of CD34⁺ cells as well as the preclinical/clinical details of CD34⁺ cell therapy for regenerative medicine.

Exosomal circ-1199 derived from EPCs exposed to oscillating shear stress acts as a sponge of let-7g-5p to promote endothelial-mesenchymal transition of EPCs by increasing HMGA2 expression

AIMS

Our previous study showed that oscillatory shear stress (OSS) induces endothelial progenitor cells (EPCs) to undergo endothelial to mesenchymal transition (EndoMT), which may contribute to the onset and progression of atherosclerosis (AS). However, the underlying mechanisms have not been elucidated. A recent study showed that exosomes (Exos) released from EPCs played a key role in various cardiovascular diseases. The purpose of this study was to identify the role and mechanism of Exos released by EPCs exposed to OSS in EPC EndoMT.

MAIN METHODS

EPCs derived from the human umbilical cord blood were cultured and characterized. The Flexcell flow STR-4000 parallel plate flow chamber system was employed to apply OSS (±3.5 dyne/cm², 1 Hz) to EPCs for 12 h. Then, Exos were extracted from the cellular supernatant (Static-Exos) or perfusate (OSS-Exos) by exoEasy Maxi Kit. Afterward, cellular intervention, angiogenesis assays, high-throughput sequencing and online database predictions were used to identify the role and mechanism of OSS-Exos in EPC EndoMT.

KEY FINDINGS

OSS-Exos inhibited angiogenesis, promoted the proliferation of EPCs both in vivo and in vitro, and induced EPC EndoMT. In addition, the expression of circ-1199 in OSS-Exos was higher than that in Static-Exos. Moreover, circ-1199 induced EPC EndoMT. The dual-luciferase reporter gene assay showed that let-7g-5p was the direct target of circ-1199. Furthermore, OSS-Exos upregulated the expression of circ-1199 and then downregulated let-7g-5p, upregulating HMGA2, which activated p-Smad3/Smad3 and Snail.

SIGNIFICANCE

OSS-Exos played an important role in the EndoMT of EPCs, which was mediated by the circ-1199/let-7g-5p/HMGA2 signaling pathway. These studies would have a high probability of revealing the mechanism of EPC EndoMT.

Microarray meta-analysis reveals IL6 and p38β/MAPK11 as potential targets of hsa-miR-124 in endothelial progenitor cells: Implications for stent re-endothelization in diabetic patients

Circulating endothelial progenitor cells (EPCs) play an important role in the repair processes of damaged vessels, favoring re-endothelization of stented vessels to minimize restenosis. EPCs number and function is diminished in patients with type 2 diabetes, a known risk factor for restenosis. Considering the impact of EPCs in vascular injury repair, we conducted a meta-analysis of microarray to assess the transcriptomic profile and determine target genes during the differentiation process of EPCs into mature ECs. Five microarray datasets, including 13 EPC and 12 EC samples were analyzed, using the online tool ExpressAnalyst. Differentially expressed genes (DEGs) analysis was done by Limma method, with an | log2FC| > 1 and FDR < 0.05. Combined p-value by Fisher exact method was computed for the intersection of datasets. There were 3,267 DEGs, 1,539 up-regulated and 1,728 down-regulated in EPCs, with 407 common DEGs in at least four datasets. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed enrichment for terms related to “AGE-RAGE signaling pathway in diabetic complications.” Intersection of common DEGs, KEGG pathways genes and genes in protein-protein interaction network (PPI) identified four key genes, two up-regulated (IL1B and STAT5A) and two down-regulated (IL6 and MAPK11). MicroRNA enrichment analysis of common DEGs depicted five hub microRNA targeting 175 DEGs, including STAT5A, IL6 and MAPK11, with hsa-miR-124 as common regulator. This group of genes and microRNAs could serve as biomarkers of EPCs differentiation during coronary stenting as well as potential therapeutic targets to improve stent re-endothelization, especially in diabetic patients.