Discovery Of Endothelial Progenitor Cells Research Articles

The Role of Endothelial Progenitor Cells in Atherosclerosis and Impact of Anti-Lipemic Treatments on Endothelial Repair.

Cardiovascular complications are associated with advanced atherosclerosis. Although atherosclerosis is still regarded as an incurable disease, at least in its more advanced stages, the discovery of endothelial progenitor cells (EPCs), with their ability to replace old and injured cells and differentiate into healthy and functional mature endothelial cells, has shifted our view of atherosclerosis as an incurable disease, and merged traditional theories of atherosclerosis pathogenesis with evolving concepts of vascular biology. EPC alterations are involved in the pathogenesis of vascular abnormalities in atherosclerosis, but many questions remain unanswered. Many currently available drugs that impact cardiovascular morbidity and mortality have shown a positive effect on EPC biology. This review examines the role of endothelial progenitor cells in atherosclerosis development, and the impact standard antilipemic drugs, including statins, fibrates, and ezetimibe, as well as more novel treatments such as proprotein convertase subtilisin/kexin type 9 (PCSK9) modulating agents and angiopoietin-like proteins (Angtpl3) inhibitors have on EPC biology.

Therapeutic Potential of Endothelial Progenitor Cells in Pulmonary Diseases.

Compromised alveolar development and pulmonary vascular remodeling are hallmarks of pediatric lung diseases such as bronchopulmonary dysplasia (BPD) and alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV). Although advances in surfactant therapy, corticosteroids, and antiinflammatory drugs have improved clinical management of preterm infants, those who suffer with severe vascular complications still lack viable treatment options. Paucity of the alveolar capillary network in ACDMPV causes respiratory distress and leads to mortality in a vast majority of infants with ACDMPV. The discovery of endothelial progenitor cells (EPCs) in 1997 brought forth the paradigm of postnatal vasculogenesis and hope for promoting vascularization in fragile patient populations, such as those with BPD and ACDMPV. The identification of diverse EPC populations, both hematopoietic and nonhematopoietic in origin, provided a need to identify progenitor cell-selective markers that are linked to progenitor properties needed to develop cell-based therapies. Focusing on the future potential of EPCs for regenerative medicine, this review will discuss various aspects of EPC biology, beginning with the identification of hematopoietic, nonhematopoietic, and tissue-resident EPC populations. We will review knowledge related to cell surface markers, signature gene expression, and key transcriptional regulators and will explore the translational potential of EPCs for cell-based therapy for BPD and ACDMPV. The ability to produce pulmonary EPCs from patient-derived induced pluripotent stem cells invitro holds promise for restoring vascular growth and function in the lungs of patients with pediatric pulmonary disorders.

Evaluation the effect of testosterone on the number of endothelial progenitor cells and amount of SDF-1α, PDGF, bFGF, and NO.

Background:Recent therapeutic advances in cardiovascular disease, thanks to the discovery of endothelial progenitor cells (EPCs). Stromal cell-derived factor-1α (SDF-1α), platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), and nitric oxide (NO) play a role in migration, homing, and differentiation of EPCs into mature endothelial cells. The incidence of cardiovascular disease is higher in men than in women. This fact suggests the influence of sex hormones on incidence of cardiovascular disease.Methods:Twenty-four female wistar rats weighing 160–180 g were randomly divided into four groups (N = 6): 1. sham-treated by sesame oil, 2. ovariectomized (OVX)-treated by sesame oil, 3. OVX-treated by 10 μg/kg/day testosterone, and 4. OVX-treated by 100 μg/kg/day testosterone. After 21 days, the animals were euthanized and blood samples were saved for determination of EPC count and serum levels of SDF-1α, PDGF, bFGF, and NO production.Results:High-dose testosterone induced significant increase in EPC count in OVX rats (P < 0.05). Also 100 μg/kg/day testosterone increased serum level of SDF-1α more than OVX-treated by 10 μg/kg/day testosterone (P < 0.05). But 10 μg/kg/day testosterone increased significantly the serum level of PDGF >100 μg/kg/day testosterone-treated group (P < 0.05). The serum level of bFGF in sham-treated by sesame oil was equal with its concentration in OVX-treated by 100 μg/kg/day testosterone. And the serum concentration of NO production in testosterone-treated groups were significantly less than other groups (P < 0.05).Conclusions:This study suggests that testosterone might be effective on cardiovascular disease in females by increasing EPC count through SDF-1α and PDGF mechanisms which are some of the vascular healing factors.

Recent Advances in Endothelial Progenitor Cells Toward Their Use in Clinical Translation.

Since the discovery of Endothelial Progenitor Cells (EPC) by Asahara and colleagues in 1997, an increasing number of preclinical studies have shown that EPC based therapy is feasible, safe, and efficacious in multiple disease states. Subsequently, this has led to several, mainly early phase, clinical trials demonstrating the feasibility and safety profile of EPC therapy, with the suggestion of efficacy in several conditions including ischemic heart disease, pulmonary arterial hypertension and decompensated liver cirrhosis. Despite the use of the common term “EPC,” the characteristics, manufacturing methods and subset of the cell type used in these studies often vary significantly, rendering clinical translation challenging. It has recently been acknowledged that the true EPC is the endothelial colony forming cells (ECFC). The objective of this review was to summarize and critically appraise the registered and published clinical studies using the term “EPC,” which encompasses a heterogeneous cell population, as a therapeutic agent. Furthermore, the preclinical data using ECFC from the PubMed and Web of Science databases were searched and analyzed. We noted that despite the promising effect of ECFC on vascular regeneration, no clinical study has stemmed from these preclinical studies. We showed that there is a lack of information registered on www.clinicaltrials.gov for EPC clinical trials, specifically on cell culture methods. We also highlighted the importance of a detailed definition of the cell type used in EPC clinical trials to facilitate comparisons between trials and better understanding of the potential clinical benefit of EPC based therapy. We concluded our review by discussing the potential and limitations of EPC based therapy in clinical settings.

Endothelial Progenitor Cells as Mediators of the Crosstalk between Vascular Repair and Immunity: Lessons from Systemic Autoimmune Diseases.

From the discovery of Endothelial Progenitor Cells (EPC), these bone marrowderived precursors have been placed as crucial mediators of the endothelial repair. Accordingly, altered levels and function of EPC have been found in different scenarios of CV risk. Despite the fact that EPC exhibit important characteristics which support a link of this cell subset with a number of inflammatory and immune networks, little is known on the actual mediators involved and the clinical relevance of these features. Systemic diseases are generally hallmarked by a vascular repair failure and increased cardiovascular disease occurrence, EPC impairment having a pivotal role. Because of their immunemediated etiology, this group of conditions represents an invaluable scenario to unravel the connections between immune dysregulation and EPC dysfunction. In the present review, we summarize the current knowledge regarding the cutting-edge area of the modulation of EPC levels and function by inflammatory cytokines in systemic diseases. We also address the possibility of the available immunomodulatory drugs to counteract this situation. Finally, due to the emerging role of the vitamin D as a common mediator in the immune system and the cardiovascular axis, we cover the topic of the role of vitamin D as a potential player in the inflammatory-mediated EPC dysfunction in systemic diseases.

Insights into Endothelial Progenitor Cells: Origin, Classification, Potentials, and Prospects.

With the discovery of endothelial progenitor cells (EPCs) in the late 1990s, a paradigm shift in the concept of neoangiogenesis occurred. The identification of circulating EPCs in peripheral blood marked the beginning of a new era with enormous potential in the rapidly transforming regenerative field. Overwhelmed with the revelation, researchers across the globe focused on isolating, defining, and interpreting the role of EPCs in various physiological and pathological conditions. Consequently, controversies emerged regarding the isolation techniques and classification of EPCs. Nevertheless, the potential of using EPCs in tissue engineering as an angiogenic source has been extensively explored. Concomitantly, the impact of EPCs on various diseases, such as diabetes, cancer, and cardiovascular diseases, has been studied. Within the limitations of the current knowledge, this review attempts to delineate the concept of EPCs in a sequential manner from the speculative history to a definitive presence (origin, sources of EPCs, isolation, and identification) and significance of these EPCs. Additionally, this review is aimed at serving as a guide for investigators, identifying potential research gaps, and summarizing our current and future prospects regarding EPCs.

Células progenitoras endoteliales en el embarazo normal y la preeclampsia

El embarazo es un reto para el sistema cardiovascular materno, necesitando de adaptación sistémica y marcados cambios locales en el útero. La adaptación cardiovascular materna al embarazo involucra una respuesta fisiológica compleja a la presencia de un feto en crecimiento, incluyendo alteraciones de las células endoteliales vasculares que contribuyen a la marcada disminución de la resistencia vascular sistémica. El descubrimiento de las células progenitoras endoteliales ha generado un considerable interés en el campo de la biología vascular. Estas células pueden ser movilizadas hacia la circulación por factores de crecimiento y pueden apoyar la salud del endotelio vascular por varios mecanismos. Estas células se originan de una población de células mononucleares circulantes y tienen la capacidad de formar nuevos vasos y contribuyen a la reparación vascular. Patologías del embarazo, como la preeclampsia, incrementan el riesgo de complicaciones y están asociadas con disfunción endotelial.

Endothelial progenitor cells and hypertension: current concepts and future implications.

The discovery of endothelial progenitor cells (EPCs), a group of cells that play important roles in angiogenesis and the maintenance of vascular endothelial integrity, has led to considerable improvements in our understanding of the circulatory system and the regulatory mechanisms of vascular homoeostasis. Despite lingering disputes over where EPCs actually originate and how they facilitate angiogenesis, extensive research in the past decade has brought about significant advancements in this field of research, establishing EPCs as an essential element in the pathogenesis of various diseases. EPC and hypertensive disorders, especially essential hypertension (EH, also known as primary hypertension), represent one of the most appealing branches in this area of research. Chronic hypertension remains a major threat to public health, and the exact pathologic mechanisms of EH have never been fully elucidated. Is there a relationship between EPC and hypertension? If so, what is the nature of such relationship-is it mediated by blood pressure alterations, or other factors that lie in between? How can our current knowledge about EPCs be utilized to advance the prevention and clinical management of hypertension? In this review, we set out to answer these questions by summarizing the current concepts about EPC pathophysiology in the context of hypertension, while attempting to point out directions for future research on this subject.

Tumor Necrosis Factor α Regulates Endothelial Progenitor Cell Migration via CADM1 and NF-kB.

Shortly after the discovery of endothelial progenitor cells (EPCs) in 1997, many clinical trials were conducted using EPCs as a cellular based therapy with the goal of restoring damaged organ function by inducing growth of new blood vessels (angiogenesis). Results were disappointing, largely because the cellular and molecular mechanisms of EPC-induced angiogenesis were not clearly understood. Following injection, EPCs must migrate to the target tissue and engraft prior to induction of angiogenesis. In this study EPC migration was investigated in response to tumor necrosis factor α (TNFα), a pro-inflammatory cytokine, to test the hypothesis that organ damage observed in ischemic diseases induces an inflammatory signal that is important for EPC homing. In this study, EPC migration and incorporation were modeled in vitro using a coculture assay where TNFα treated EPCs were tracked while migrating toward vessel-like structures. It was found that TNFα treatment of EPCs increased migration and incorporation into vessel-like structures. Using a combination of genomic and proteomic approaches, NF-kB mediated upregulation of CADM1 was identified as a mechanism of TNFα induced migration. Inhibition of NF-kB or CADM1 significantly decreased migration of EPCs in vitro suggesting a role for TNFα signaling in EPC homing during tissue repair. Stem Cells 2016;34:1922-1933.

Diabetes, Endothelial Dysfunction, and Vascular Repair: What Should a Diabetologist Keep His Eye on?

Cardiovascular complications are the most common complications of diabetes mellitus. A prominent attribute of diabetic cardiovascular complications is accelerated atherosclerosis, considered as a still incurable disease, at least at more advanced stages. The discovery of endothelial progenitor cells (EPCs), able to replace old and injured mature endothelial cells and capable of differentiating into healthy and functional endothelial cells, has offered the prospect of merging the traditional theories on the pathogenesis of atherosclerosis with evolving concepts of vascular biology. The literature supports the notion that EPC alterations are involved in the pathogenesis of vascular diseases in diabetics, but at present many questions remain unanswered. In this review the aspects linking endothelial progenitor cells to the altered vascular biology in diabetes mellitus are discussed.

Advance in prevention and treatment of ischemia cardio-cerebrovascular disease through increased therapeutic angiogenesis induced by traditional Chinese medicine

Remaining organic and functional damage of ischemia cardio-cerebrovascular disease is always a main trouble puzzling the clinicians. After the discovery of endothelial progenitor cells (EPCs), researchers realize that postnatal angiogenesis is an important biological process, which play a key role to repair the ischemia tissue and improve the function. So a new concept which names therapeutic angiogenesis supply a new treament way for the ischemia cardio-cerebrovascular disease. Traditional Chinese medicine (TCM) has accumulated rich experience on treating the ischemia disease, studies found that many Chinese medicine prescriptions and effective ingredients can increase the therapeutic angiogenesis, howerer the mechanisms were not the same, they mainly manifest in regular the secretion of angiogenic factors, increase the proliferation and differentiation etc. In this paper, we review recent studies, summary the Chinese medicine prescriptions and effective ingredients which can increase the therapeutic angiogenesis, and analyze the differernt pathway. We view to provide reference for the later researchers.

Role of formyl peptide receptor 2 in homing of endothelial progenitor cells and therapeutic angiogenesis.

Endothelial progenitor cells (EPCs) hold a great promise as a therapeutic mediator in treatment of ischemic disease conditions. The discovery of EPCs in adult blood has been a cause of significant enthusiasm in the field of endothelial cell research and numerous clinical trials have been expedited. After more than a decade of research in basic science and clinical applications, limitations and new strategies of EPC therapeutics have emerged. With various phenotypes, vague definitions, and uncertain distinction from hematopoietic cells, understanding EPC biology remains challenging. However, EPCs, still hold great hope for treatment of critical ischemic injury as low concern regarding safety can accelerate the clinical applications from basic findings. This review provides an introduction to EPC as cellular therapeutics, which highlights a recent finding that EPC homing was promoted through FPR2 signaling.

The acute exposure effects of inhaled nickel nanoparticles on murine endothelial progenitor cells

Introduction: The discovery of endothelial progenitor cells (EPCs) may help to explain observed cardiovascular effects associated with inhaled nickel nanoparticle exposures, such as increases in vascular inflammation, generation of reactive oxygen species, altered vasomotor tone and potentiated atherosclerosis in murine species.Methods: Following an acute whole body inhalation exposure to 500 µg/m3 of nickel nanoparticles for 5 h, bone marrow EPCs from C57BL/6 mice were isolated. EPCs were harvested for their RNA or used in a variety of assays including chemotaxis, tube formation and proliferation. Gene expression was assessed for important receptors involved in EPC mobilization and homing using RT-PCR methods. EPCs, circulating endothelial progenitor cells (CEPCs), circulating endothelial cells (CECs) and endothelial microparticles (EMPs) were quantified on a BD FACSCalibur to examine endothelial damage and repair associated with the exposure.Results and conclusions: Acute exposure to inhaled nickel nanoparticles significantly increased both bone marrow EPCs as well as their levels in circulation (CEPCs). CECs were significantly elevated indicating that endothelial damage occurred due to the exposure. There was no significant difference in EMPs between the two groups. Tube formation and chemotaxis, but not proliferation, of bone marrow EPCs was impaired in the nickel nanoparticle exposed group. These results coincided with a decrease in the mRNA of receptors involved in EPC mobilization and homing. These data provide new insight into how an acute nickel nanoparticle exposure to half of the current Occupational Safety & Health Administration (OSHA) permissible exposure limit may adversely affect EPCs and exacerbate cardiovascular disease states.

Cellular strategies to promote vascularisation in tissue engineering applications

Vascularisation is considered to be one of the greatest challenges in tissue engineering. Different strategies exist but cell-based approaches have emerged as a promising therapy to achieve successful vascularisation. The use of endothelial cells to engineer vascularised tissues has been extensively investigated. This field of research has evolved with the discovery of endothelial progenitor cells, a subpopulation with a high regenerative potential. However, the survival of endothelial cell populations alone seems to be impaired. To overcome this problem, co-culture systems, involving supporting cells, like mural cells, fibroblasts, or more tissue-specific cells have been developed. Endothelial cells benefit from the extracellular matrix components and growth factors produced by the supporting cells, which results in neovessel stabilisation and maturation. The use of endothelial progenitor cells in co-culture systems appears to be a promising strategy to promote vascularisation in approaches of increasing complexity. Herein, the authors provide an overview of the cellular strategies that can be used for increasing vascularisation in tissue engineering and regeneration.

Endothelial Progenitor Cells in Cardiovascular Disease and Chronic Inflammation: from Biomarker to Therapeutic Agent

The discovery of endothelial progenitor cells in the 1990s challenged the paradigm of angiogenesis by showing that cells derived from hematopoietic stem cells are capable of forming new blood vessels even in the absence of a pre-existing vessel network, a process termed vasculogenesis. Since then, the majority of studies in the field have found a strong association between circulating endothelial progenitor cells and cardiovascular risk. Several studies have also reported that inflammation influences the mobilization and differentiation of endothelial progenitor cells. In this review, we discuss the emerging role of endothelial progenitor cells as biomarkers of cardiovascular disease as well as the interplay between inflammation and endothelial progenitor cell biology. We will also review the challenges in the field of endothelial progenitor cell-based therapy.

The ontogeny of endothelial progenitor cells through flow cytometry

Since the discovery of endothelial progenitor cells (EPCs), there have been conflicting reports as to the precise phenotypic identity, and thus an accurate description of the function of these cells in disease pathology is lacking. This review will detail the protocols that have been published within 2010 to help decipher the true identity of the various cells that have been reported as EPCs in numerous clinical trials. Throughout 2010, three protocols have been published alleging to identify EPCs, yet only one provides a true nonhematopoietic origin for a cell that is classified as an EPC. In addition to the protocols published to try to establish a consensus definition, 10 studies involving EPCs across disease pathologies were published with various degrees of correlation to disease phenotype and cellular level. A true phenotypic definition of a circulating EPC capable of becoming an endothelial colony forming cell with proliferative potential has been given. It is now time the EPC field drops this ambiguous term (i.e. EPCs), as many studies purporting to measure EPCs are in fact still quantifying cells of a hematopoietic origin. It is necessary for cross study comparisons that a uniform phenotypic definition be adhered to when using the term EPC.

Endothelial progenitor cells as a new marker of endothelial function with respect to risk of cardiovascular disorders

The discovery of endothelial progenitor cells (EPC), over a decade ago, has refuted the previous belief that vasculogenesis only occurs during embryogenesis. The results of several studies revealed altered number and impaired function of EPC in hyperlipidemia, hypertension, diabetes, obesity as well as in rheumatoid arthritis. The population of developmental age is characterized by higher counts of EPC compared to adults. However, among young patients with chronic disorders that affect the vascular system, the number of EPC decreases. The reduced circulating concentration of EPC has become a surrogate marker of endothelial function and has been implicated in the pathogenesis of many vascular diseases. This article aims to review the biology and pathophysiology of EPC in the conditions of cardiovascular risk factors. The potential possibilities of increasing EPC number and function as well as the use of EPC in the treatment of vascular pathology will also be discussed.

Rosiglitazone Attenuates Endothelial Progenitor Cell Apoptosis Induced by TNF-α via ERK/MAPK and NF-κB Signal Pathways

The discovery of endothelial progenitor cells (EPCs) provides us with a novel treatment strategy for complications requiring therapeutic revascularization and vascular repair. However, the feasibility of this strategy may be limited due to reduced number and impaired function of EPCs under stimulation of TNF-α. The present study was designed to investigate the effect of rosiglitazone on EPC apoptosis induced by TNF-α and the molecular mechanisms involved. Rosiglitazone attenuated apoptosis of TNF-α-stimulated EPCs in a dose-dependent manner. Rosiglitazone decreased caspase-3 activity and cleavages of caspase-3, caspase-7, and parp. Rosiglitazone also moderated the dissipation of mitochondrial membrane potential caused by TNF-α treatment and reduced the expression of bax and the release of cytochrome c. Furthermore, rosiglitazone inhibited phosphorylations of ERK/MAPK and NF-κB signal molecules. Both ERK and NF-κB inhibitors decreased TNF-α-induced apoptosis of EPCs, as well as the expression of cleaved caspase-3 and parp. These results suggest that rosiglitazone may mediate the inhibitory effect on EPCs apoptosis under TNF-α stimulation through suppression of ERK/MAPK and NF-κB signal pathways.

Endothelial Progenitor Cells: Hope Beyond Controversy

The capacity to induce new blood vessel formation or to repair damaged vessels is an attractive idea that has, for a long time, captured the attention and imagination of researchers. Beside the identification of the pro-angiogenic growth factors and their counterpart inhibitors, the discovery of endothelial progenitor cells (EPC) in adults and their putative vascular-promoting and/or vascular-healing properties, has generated some of the biggest fascination and debate in the broad field of vascular biology. The simple concept of a population of undifferentiated cells being able to generate new endothelial cells and the corresponding blood vessels in adults is both intriguing and, as seen in the last 10 years, controversial. Academic rivalry or pure scientific dispute has accompanied the research on EPC for some time. The major issues put forward by opposing groups of scientists regarding the identity and the role of EPCs as well as the optimal isolation and detection techniques are discussed in this review. The clinical relevance of EPCs and their potential applications in cancer treatments are also highlighted.

Cell-based methods for ex vivo evaluation of human endothelial biology

The endothelium plays a central role in cardiovascular regulation. Endothelial cells produce a variety of vasculoregulatory and vasculotropic molecules that act locally or at distant sites. Alteration of the vascular endothelium is a primary event in the pathogenesis of vascular diseases, such as atherosclerosis, as well as systemic and pulmonary hypertension. For these reasons, the study of human endothelium has become central in cardiovascular research. Unfortunately, technologies handling endothelial cells in vitro are often criticized due to the uncertain transferability of results to intact organs and, importantly, to humans. Although methods to assess endothelial function non-invasively have been available for decades, cell-based approaches for the direct ex vivo evaluation of endothelial cell biology in humans have been devised only recently. The discovery of endothelial progenitor cells opened the way for studies on vascular regeneration, while it has been recognized that mature circulating endothelial cells mainly represent a consequence of the ongoing vascular damage. Coupled with a minimally invasive way to obtain fresh human endothelial cells through an endovascular biopsy, these new methods provide a novel outlook on human endothelial cells as close as possible to their natural environment. In this review, we will summarize the current knowledge and the methodological perspective of these cell-based methods.