Circulating endothelial cells, circulating endothelial progenitor cells, and von Willebrand factor in pregnancies complicated by hypertensive disorders

Dynamics of Endothelial Cell Diversity and Plasticity in Health and Disease

Endothelial cells (ECs) are vital structural units of the cardiovascular system possessing two principal distinctive properties: heterogeneity and plasticity. Endothelial heterogeneity is defined by differences in tissue-specific endothelial phenotypes and their high predisposition to modification along the length of the vascular bed. This aspect of heterogeneity is closely associated with plasticity, the ability of ECs to adapt to environmental cues through the mobilization of genetic, molecular, and structural alterations. The specific endothelial cytoarchitectonics facilitate a quick structural cell reorganization and, furthermore, easy adaptation to the extrinsic and intrinsic environmental stimuli, known as the epigenetic landscape. ECs, as universally distributed and ubiquitous cells of the human body, play a role that extends far beyond their structural function in the cardiovascular system. They play a crucial role in terms of barrier function, cell-to-cell communication, and a myriad of physiological and pathologic processes. These include development, ontogenesis, disease initiation, and progression, as well as growth, regeneration, and repair. Despite substantial progress in the understanding of endothelial cell biology, the role of ECs in healthy conditions and pathologies remains a fascinating area of exploration. This review aims to summarize knowledge and concepts in endothelial biology. It focuses on the development and functional characteristics of endothelial cells in health and pathological conditions, with a particular emphasis on endothelial phenotypic and functional heterogeneity.

Decreased toll-like receptor 4 and CD11b/CD18 expression on peripheral monocytes of hypertensive patients correlates with a lesser extent of endothelial damage: a preliminary study

BACKGROUND

Low-grade chronic inflammation is recognized to contribute to the physiopathology of arterial hypertension. Therefore, this study aimed to assess the pro-inflammatory phenotype of peripheral monocytes of hypertensive patients by analyzing Toll-like receptor 4 (TLR4) and CD11b/CD18 surface expression. In the second part, the influence of phenotypic alterations of monocytes on the endothelial status reflected by circulating endothelial cells (CECs) was evaluated.

PATIENTS

The study included 60 patients with arterial hypertension, who were divided into two subgroups based on the disease severity according to the applicable criteria. The mild hypertension and resistant hypertension groups included 30 patients each. The control group consisted of 33 normotensive volunteers matched for age and sex.

RESULTS

Both in the entire group of patients and individual subgroups, reduced surface expression of TLR4 and CD11b/CD18 was found compared to normotensive volunteers. A reduced percentage of monocytes with the CD14 + TLR4 + immunophenotype was correlated with a lower MFI level of CD18 and CD11b in the entire group of patients and after division only in the mild hypertension group. Reduced surface expression of TLR4 in hypertensive patients correlated with a lower number of CECs. This relationship was not observed in the resistant hypertension group; instead, an independent effect of reduced CD11b/CD18 expression on the reduction of CEC number was demonstrated.

CONCLUSION

Our preliminary study showed for the first time that hypertension of varying severity is accompanied by phenotypic changes in monocytes, manifested by reduced surface expression of both TLR4 and CD11b/CD18. These phenotypic changes were associated with a reduced degree of endothelial injury. Our study opens a new, unexplored area of research on the protective features of peripheral monocytes in hypertension.

Pathophysiology of Pre-Eclampsia-Two Theories of the Development of the Disease

Pre-eclampsia (PE) continues to be a leading cause of maternal and fetal mortality and morbidity. While substantial progress has been made in understanding the pathomechanisms of PE, the pathophysiology of the disease is still not fully understood. While the "two-stage model" of the development of PE is the most widely accepted theory, stating that the placenta is the main source of the disease, there are some other pathophysiological models of PE. Among these other theories, the one considering heart dysfunction as serving as the primary cause of PE seems to be gaining increasing prominence. In this review, we aim to elucidate these two divergent concepts concerning the development of PE. Despite some differences in their proposed pathomechanisms, both theories share vital pathophysiological elements in common. A central and critical component in both models is impaired placental perfusion, which appears to be a crucial phenomenon in PE. A comprehensive understanding of the different pathomechanisms involved in PE may be helpful in clinical practice, prompting a more individual approach to care of patients with PE.

Restenosis after Coronary Stent Implantation: Cellular Mechanisms and Potential of Endothelial Progenitor Cells (A Short Guide for the Interventional Cardiologist)

Coronary stents are among the most common therapies worldwide. Despite significant improvements in the biocompatibility of these devices throughout the last decades, they are prone, in as many as 10–20% of cases, to short- or long-term failure. In-stent restenosis is a multifactorial process with a complex and incompletely understood pathophysiology in which inflammatory reactions are of central importance. This review provides a short overview for the clinician on the cellular types responsible for restenosis with a focus on the role of endothelial progenitor cells. The mechanisms of restenosis are described, along with the cell-based attempts made to prevent it. While the focus of this review is principally clinical, experimental evidence provides some insight into the potential implications for prevention and therapy of coronary stent restenosis.

Venous thrombosis risk factors in pregnant women

Venous thromboembolism (VTE) is the third most common cause of death on Earth after myocardial infarctions and strokes, according to the World Health Organization (WHO). Pregnancy is a unique condition of woman, when enormous changes occur in functioning of the most important systems of homeostasis in a relatively short time. These are physiological hypercoagulation, slowing of blood flow, increase in circulating blood volume, etc. However, while being physiological, these changes increase the risks of venous thromboembolism by almost 6 times. In some cases, there appears an imbalance or dissociation between the functioning of natural antithrombotic systems and the activation of coagulation as a consequence of genetically or acquired determined causes (genetic thrombophilia, antiphospholipid syndrome, comorbidities, obstetric complications and other exogenous and endogenous factors). Accordingly, identification of risk factors, their systematization, and determination of VTE risks in pregnancy and puerperium is one of the most important tasks of clinical medicine. Various recommendations have appeared for practitioners during the last 10-15 years on the basis of the risk factors analysis in order to prevent VTE in pregnant women more effectively. Nevertheless, none of these recommendations can yet take into account all risk factors, although convenient scoring systems have emerged for risk assessment and clear recommendations on anti-thrombotic prophylaxis regimens in risk groups in recent years. This article will review historical understanding of thrombosis in pregnant women, progress in understanding VTE risk factors in pregnant women, and available reserves in identifying new risk factors during pregnancy and puerperium in order to stratify risks more efficiently.

Endothelial Dysfunction in Pregnancy Complications

The endothelium, which constitutes the inner layer of blood vessels and lymphatic structures, plays an important role in various physiological functions. Alterations in structure, integrity and function of the endothelial layer during pregnancy have been associated with numerous gestational complications, including clinically significant disorders, such as preeclampsia, fetal growth restriction, and diabetes. While numerous experimental studies have focused on establishing the role of endothelial dysfunction in pathophysiology of these gestational complications, their mechanisms remain unknown. Numerous biomarkers of endothelial dysfunction have been proposed, together with the mechanisms by which they relate to individual gestational complications. However, more studies are required to determine clinically relevant markers specific to a gestational complication of interest, as currently most of them present a significant overlap. Although the independent diagnostic value of such markers remains to be insufficient for implementation in standard clinical practice at the moment, inclusion of certain markers in predictive multifactorial models can improve their prognostic value. The future of the research in this field lies in the fine tuning of the clinical markers to be used, as well as identifying possible therapeutic techniques to prevent or reverse endothelial damage.

Long noncoding RNA p21 enhances autophagy to alleviate endothelial progenitor cells damage and promote endothelial repair in hypertension through SESN2/AMPK/TSC2 pathway

Vascular damage of hypertension has been the focus of hypertension treatment, and endothelial progenitor cells (EPCs) play an important role in the repair of vascular endothelial damage. Functional damage and decreased number of EPCs are observed in the peripheral circulation of hypertensive patients, but its mechanism is not yet elucidated. Here, we show that the number of EPCs in hypertensive patients is significantly lower than that of normal population, and the cell function decreases with a higher proportion of EPCs at later stages. A decrease in autophagy is responsible for the senescence and damage of EPCs induced by AngII. Moreover, lncRNA-p21 plays a critical regulator role in EPCs' senescence and dysfunction. Furthermore, lncRNA-p21 activates SESN2/AMPK/TSC2 pathway by promoting the transcriptional activity of p53 and enhances autophagy to protect against AngII-induced EPC damage. The data provide evidence that a reversal of decreased autophagy serves as the protective mechanism of EPC injury in hypertensive patients, and lncRNA-p21 is a new therapeutic target for vascular endothelial repair in hypertension.

Serum levels of soluble FMS-like tyrosine kinase 1 and endothelial glycocalyx components in early- and late-onset preeclampsia

INTRODUCTION

The most popular model of preeclampsia (PE) is a two-stage one in which the first stage involves a decreased perfusion of the placenta and the second stage is characterized by maternal endothelial injury and dysfunction. This model seems to be more appropriate for early-onset PE, than for the late-onset disease, as in the case of the latter the event of reduced placental perfusion seems is less obvious.The aim of the study was to assess the possible correlations between the serum levels of soluble FMS-like tyrosine kinase 1 (sFlt-1) and the components of endothelial glycocalyx (EG), namely syndecan -1 (SDC-1) and hyaluronan (HA), as the markers of endothelial damage, in patients with early- and late-onset PE.

MATERIALS AND METHODS

The study was conducted among 60 women in their late second and third trimester of the singleton pregnancy, including 20 patients with early-onset PE, 20 with late-onset PE, and 20 women with normal pregnancy, who served as the control group. All patients were hospitalized between 2015 and 2018 at the Division of Reproduction of Poznan University of Medical Sciences. The women in the control group were matched by gestational age with the patients in the study groups.

RESULTS

The median serum level of sFlt-1 was the highest in the patients with early-onset PE (3.53 (2.73-4.5) pg/ml) but it was not statistically different from the level in the patients with late-onset PE (3.14 (2.2-3.4) pg/ml). The mean serum level of SDC-1 also did not differ significantly between the two groups of patients with PE (6.17 ± 2.2 ng/ml in early-onset PE; 6.42 ± 2.2 ng/ml in late-onset PE). Both values of SDC-1 were significantly lower than that in the healthy pregnant women (11 ± 2.62 ng/ml, p < .001). The median concentrations of HA did not differ between patients with early- (236.6 (101.1-351.9) ng/ml) and late-onset PE (234.7 (46.8-324.2) ng/ml). However, the levels in these study groups were significantly higher than in the control group (113.9 (30.9-379.8) ng/ml, p < .001). There was no significant correlation found between the serum concentrations of sFlt-1 and both HA and SDC-1; however, such trend was noticed between the serum concentrations of sFlt-1 and HA in patients with early-onset PE, but not in those with the late-onset disease.

CONCLUSIONS

Evaluation of serum concentrations of HA in patients with PE was found to be more useful in the assessment of endothelial injury, compared to the assessment of SDC-1.The degree of EG damage was comparable in patients with early- and late-onset PE. The pathomechanism of the damage seems to be more sFlt-1 dependent in patients withearly- onset PE than in the case of late-onset disease. The two-stage model of PE is more appropriate for early - onset PE, whereas the pathophysiology of the late-onset disease is rather more complex and heterogenous.

The Role of HIV Infection in the Pathophysiology of Gestational Diabetes Mellitus and Hypertensive Disorders of Pregnancy

Purpose of the Review: The main objective of this study is to investigate mechanisms associated with gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) in HIV infected pregnant women by looking how placental hormones such as (progesterone and prolactin) and basic haemostatic parameters are regulated in HIV infected pregnancies.

Recent Findings: HIV/AIDS are a major global obstetric health burden that lead to increased rate of morbidity and mortality. HIV/AIDS has been associated with the pathophysiology of GDM and HDP. Increased risk of GDM due to highly active antiretroviral therapy (HAART) usage has been reported in HIV infected pregnancies, which causes insulin resistance in both pregnant and non-pregnant individuals. HAART is a medication used for lowering maternal antepartum viral load and pre-exposure and post-exposure prophylaxis of the infant. In pregnant women, HAART induces diabetogenic effect by causing dysregulation of placental hormones such as (progesterone and prolactin) and predispose HIV infected women to GDM. In addition to HIV/AIDS and GDM, Studies have indicated that HIV infection causes haemostatic abnormalities such as hematological disorder, deregulated haematopoiesis process and the coagulation process which results in HDP.

Summary: This study will help on improving therapeutic management and understanding of the pathophysiology of GDM and HDP in the absence as well as in the presence of HIV infection by reviewing studies reporting on these mechanism.

VWCE Functions as a Tumor Suppressor in Breast Cancer Cells

Breast cancer remains a leading cause of cancer-related death, for which the majority of deaths result from metastases. Von Willebrand factor C and EGF domain (VWCE) is a member of the Von Willebrand factor (VWF) gene family; however, its function, regulatory mechanism, and clinical value in breast cancer remain unclear. In the present study, we sought to elucidate the role of VWCE in breast cancer metastasis. We examined the expression of VWCE in breast cancer tissues and normal control tissues of 50 breast cancer patients. We found that VWCE expression was downregulated in breast cancer cells and tissues compared to normal breast epithelial cells or the adjacent normal tissues. To explore the role of VWCE in human breast cancer development, we introduced a VWCE-overexpressing or control lentiviral vector into the breast cancer MDA-MB-453 and MDA-MB-231 lines in vitro. The overexpression of VWCE inhibited the proliferation, migration, invasion, and chemoresistance of the breast cancer cell lines. More importantly, the forced expression of VWCE suppressed tumor formation and metastasis in nude mice. iTRAQ-based quantitative proteomic analysis revealed that VWCE overexpression induced a 10-fold decrease in the level of WD-repeat domain 1 (WDR1) protein expression. Rescue experiments further verified that WDR1 was a downstream molecule of VWCE, and WDR1 overexpression reversed the above effects of VWCE overexpression on tumor growth. Therefore, VWCE may represent a novel tumor suppressor, for which its deregulation promotes breast cancer progression via the upregulation of WDR1.

Venous thrombosis risk factors in pregnant women

OBJECTIVES

Assess all risk factors of venous thromboembolism (VTE) in pregnancy and puerperium.

METHODS

Different guidelines for VTE prevention have been analyzed.

RESULTS

Various recommendations have appeared for practitioners during the last 10-15 years on the basis of the risk factors analysis in order to prevent VTE in pregnant women more effectively. Nevertheless, none of these recommendations can yet take into account all risk factors, although convenient scoring systems have emerged for risk assessment and clear recommendations on anti-thrombotic prophylaxis regimens in risk groups in recent years.

CONCLUSIONS

VTE is the third most common cause of death on Earth after myocardial infarctions and strokes, according to the World Health Organization. Pregnancy is a unique condition of woman, when enormous changes occur in functioning of the most important systems of homeostasis in a relatively short time. These are physiological hypercoagulation, slowing of blood flow, increase in circulating blood volume, etc. However, while being physiological, these changes increase the risks of venous thromboembolism by almost six times. In some cases, there appears an imbalance or dissociation between the functioning of natural antithrombotic systems and the activation of coagulation as a consequence of genetically or acquired determined causes (genetic thrombophilia, antiphospholipid syndrome, comorbidities, obstetric complications and other exogenous and endogenous factors). Accordingly, identification of risk factors, their systematization, and determination of VTE risks in pregnancy and puerperium is one of the most important tasks of clinical medicine. This article will review historical understanding of thrombosis in pregnant women, progress in understanding VTE risk factors in pregnant women, and available reserves in identifying new risk factors during pregnancy and puerperium in order to stratify risks more efficiently.

Endothelial progenitor cells as the target for cardiovascular disease prediction, personalized prevention, and treatments: progressing beyond the state-of-the-art

Stimulated by the leading mortalities of cardiovascular diseases (CVDs), various types of cardiovascular biomaterials have been widely investigated in the past few decades. Although great therapeutic effects can be achieved by bare metal stents (BMS) and drug-eluting stents (DES) within months or years, the long-term complications such as late thrombosis and restenosis have limited their further applications. It is well accepted that rapid endothelialization is a promising approach to eliminate these complications. Convincing evidence has shown that endothelial progenitor cells (EPCs) could be mobilized into the damaged vascular sites systemically and achieve endothelial repair in situ, which significantly contributes to the re-endothelialization process. Therefore, how to effectively capture EPCs via specific molecules immobilized on biomaterials is an important point to achieve rapid endothelialization. Further, in the context of predictive, preventive, personalized medicine (PPPM), the abnormal number alteration of EPCs in circulating blood and certain inflammation responses can also serve as important indicators for predicting and preventing early cardiovascular disease. In this contribution, we mainly focused on the following sections: the definition and classification of EPCs, the mechanisms of EPCs in treating CVDs, the potential diagnostic role of EPCs in predicting CVDs, as well as the main strategies for cardiovascular biomaterials to capture EPCs.

Vitamin D Sufficiency Has a Limited Effect on Placental Structure and Pathology: Placental Phenotypes in the VDAART Trial

Vitamin D insufficiency during pregnancy is widespread. The effects of active vitamin D on the human placenta in vivo are unknown. We test the hypotheses that 25(OH)D sufficiency (arbitrarily defined as 25(OH)D ≥32 ng/mL) modulates placental structure and function in vivo in a population of women whose offspring are at risk for childhood asthma, and that placental pathology is more common in offspring that evolve asthma at age 3. Pregnant volunteers in the St. Louis, MO, cohort of the Vitamin D Antenatal Asthma Reduction Trial (VDAART, NIH grant #HL091528) participated in a nested case-control study and consented for the study of placentas after delivery. Maternal concentrations of 25(OH)D were measured at trial entry and in the third trimester. The histopathology of the placentas from women with sufficient 25(OH)D, versus insufficient, showed no clinically significant differences, but morphometry revealed villi of women with sufficient third-trimester 25(OH)D had a higher villous surface density. Notably, analyses of transcripts, extracted from formalin-fixed paraffin-embedded specimens, revealed higher expression of INTS9, vWF, MACC1, and ARMS2, and diminished expression of the CNTN5 genes in the insufficient group. A larger proportion of placentas showed chronic chorioamnionitis in offspring with versus without asthma at age 3. These findings suggest that maternal 25(OH)D insufficiency has a limited effect on human placental villous histopathology and morphometry, but attenuates a small number of placental gene expression profiles in this selected population. The association of placental chronic chorioamnionitis and offspring asthma is worthy of further study.

Proteasome Levels and Activity in Pregnancies Complicated by Severe Preeclampsia and Hemolysis, Elevated Liver Enzymes, and Thrombocytopenia (HELLP) Syndrome

Excessive accumulation of misfolded proteins was recently demonstrated in preeclampsia. We examined levels and activity of circulatory proteasome and immunoproteasome (inflammatory subtype) in preeclampsia and hemolysis, elevated liver enzymes, and thrombocytopenia (HELLP) syndrome. We analyzed samples from women with hypertensive pregnancy disorders (n=115), including preeclampsia with severe features (sPE) and HELLP syndrome, and normotensive controls (n=45). Plasma proteasome and immunoproteasome immunoreactivity were determined by quantifying the α-subunit of the 20S core and β5i (proteasome subunit beta 8 [PSMB8]), respectively. Plasma proteasome activity was analyzed with fluorogenic substrates. MG132, lactacystin, and ONX0914 were used to inhibit the circulating proteasome and immunoproteasome, respectively. Plasma cytokine profiles were evaluated by multiplex immunoassay. Placental expression of β5 (constitutive proteasome) and β5i (immunoproteasome) was interrogated by immunohistochemistry. Women with sPE had increased plasma 20S levels ( P<0.001) and elevated lytic activities (chymotrypsin-like 7-fold, caspase-like 4.2-fold, trypsin-like 2.2-fold; P <0.001 for all) compared with pregnant controls. Women with features of HELLP displayed the highest plasma proteasome levels and activity, which correlated with decreased IFN-γ (interferon-γ), and increased IL (interleukin)-8 and IL-10. In sPE and HELLP, chymotrypsin-like activity was suppressed by proteasome inhibitors including ONX0914. Compared with gestational age-matched controls, sPE placentas harbored increased β5 and β5i immunostaining in trophoblasts. β5i signal was elevated in HELLP with predominant staining in villous core, extravillous trophoblasts in placental islands, and extracellular vesicles in intervillous spaces. Pregnancy represents a state of increased proteostatic stress. sPE and HELLP were characterized by significant upregulation in circulating levels and lytic activity of the proteasome that was partially explained by placental immunoproteasome upregulation.

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

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

The Potential Role of Circulating Endothelial Cells and Endothelial Progenitor Cells in the Prediction of Left Ventricular Hypertrophy in Hypertensive Patients

Background

The main aim of present study is to evaluate the potential role of circulating endothelial cells (CECs) and endothelial progenitor cells (CEPCs) – representing specific markers of endothelial damage, in the prediction of left ventricular hypertrophy (LVH) in hypertensive patients categorized into two groups; mild (MH) and resistant hypertension (RH).

Materials and Methods

Thirty patients with MH and 28 subjects with RH were involved in the study. In both groups, patients were divided into an LVH and non-LVH group. The control group included 33 age and sex-matched normotensive volunteers. Physical examination, laboratory tests and echocardiography were conducted.

Results

In both the MH and RH group, patients with as well as without LVH demonstrated a higher number of CECs and a lower ratio of CEPCs/CECs as compared to the healthy control. Multiple linear regression analysis showed a positive association of CEPCs with left ventricular mass (LVM) and left ventricular mass index (LVMI), independently of other confounders.

Conclusion

Our results suggest that endothelial injury observed as an elevated CECs number and its impaired regeneration, reflected by a lowered CEPCs/CECs ratio, precede LVH occurrence and may play a significant role in LVH development regardless of the clinical severity of hypertension. Moreover, independent correlation of CEPCs with echocardiographic (ECG) incidences of LVH suggests their potential use as a screening biomarker to stratify the risk of LVH development.

CD-34+ and VE-cadherin+ endothelial progenitor cells in preeclampsia and normotensive pregnancies

OBJECTIVE

The objective of our study was to determine levels of endothelial progenitor cells (EPCs) in preeclampsia and normotensive pregnant women.

STUDY DESIGN

Prospective cohort study of women with preeclampsia and normotensive pregnancies. EPCs were estimated by flow cytometry. Multiple linear regression was used to assess the association of EPCs with preeclampsia adjusting for maternal age, body mass index (BMI), gestation and ethnicity.

MAIN OUTCOME MEASURE

Levels of EPCs in preeclampsia and normotensive pregnancies, with CD-34 and vascular endothelial (VE)-cadherin as markers of EPCs. VE-cadherin is an endothelial cell adhesion molecule used to delineate endothelial lineage of EPCs.

RESULTS

There were thirty women in the preeclampsia group and thirty-three in the normotensive group. The two groups were similar except for the BMI and blood pressures, which were higher in preeclampsia. On multiple linear regression, EPCs numbers were significantly higher by 29 (95% confidence interval 11.7-46.6, p = 0.001) in preeclampsia compared to the normotensive group. There was significant positive correlation between EPCs and systolic blood pressure in preeclampsia (Spearman correlation coefficient 0.39, p = 0.03).

CONCLUSION

Although widely used in cardiovascular disease other than preeclampsia, this is the first study using VE-cadherin as a marker of endothelial lineage to define EPCs in preeclampsia. Our results suggest the higher number of EPCs in preeclampsia may be a response of the bone marrow to endothelial injury.

Von Willebrand factor contribution to pathophysiology outside of von Willebrand disease

VWF is a procoagulant protein that plays a central role in the initiation of platelets aggregate formation and thrombosis. While von Willebrand disease has long been known to result from qualitative and quantitative deficiencies of VWF, it is recently that contribution of elevated levels of VWF to various pathological conditions including thrombosis, inflammation, angiogenesis, and cancer metastasis has been appreciated. Here, we discuss contribution of elevated levels of VWF to various thrombotic and nonthrombotic pathological conditions.