Endocan, a putative endothelial cell marker, is elevated in preeclampsia, decreased in acute pyelonephritis, and unchanged in other obstetrical syndromes

Acute pyelonephritis in pregnancy and plasma syndecan-1: evidence of glycocalyx involvement

BACKGROUND

Acute pyelonephritis, a risk factor for maternal sepsis, adult respiratory distress syndrome, and preterm labor, is a frequent cause of hospitalization. This condition is characterized by excessive intravascular inflammation and endothelial cell activation and dysfunction. Syndecan-1, a major component of the glycocalyx, is a gel-like layer that covers the luminal surface of healthy endothelial cells, preserving and mediating many endothelial functions. During pregnancy, there is an additional potential source of syndecan-1, the "syncytiotrophoblast glycocalyx," which lines the intervillous space. Insults that damage the glycocalyx lead to a shedding of syndecan-1 into the circulation. Hence, syndecan-1 has been proposed as a marker of endothelial injury in conditions such as sepsis, trauma, cardiovascular disease, and diabetes mellitus.

OBJECTIVE

The objective of this study was to determine whether the plasma syndecan-1 concentration changes in women with acute pyelonephritis in the presence or absence of bacteremia.

STUDY DESIGN

This cross-sectional study included three groups: (1) non-pregnant women (n = 25); (2) women with an uncomplicated pregnancy from whom samples were collected preterm (n = 61) or at term (n = 69); and (3) pregnant women diagnosed with acute pyelonephritis from whom samples were collected at the time of diagnosis during the second and third trimesters (n = 33). The diagnosis of acute pyelonephritis was based on clinical findings and a positive urine culture for bacteria. Blood culture results were available in 85% (28/33) of women with acute pyelonephritis. Plasma concentrations of syndecan-1 were determined by a validated immunoassay.

RESULTS

(1) Women with an uncomplicated pregnancy had a higher plasma concentration of syndecan-1 than non-pregnant women. The geometric mean (95% confidence interval [CI]) of syndecan-1 concentration was 51.0 (12.1-216.1) ng/mL in non-pregnant controls; 1280 (365-4487) ng/mL in normal preterm gestations; and 1786 (546-5834) ng/mL in normal term gestations (adjusted p < .005 for all three between group comparisons); (2) plasma syndecan-1 concentrations increased with gestational age among women with a normal pregnancy (p < .001, R2 = 0.27); (3) syndecan-1 multiple of the mean (MoM) values in pregnant patients with acute pyelonephritis were higher than those in normal pregnant women based on second- and third-trimester samples (p = .048, 1.26-fold change). The increase was driven primarily by cases with a positive blood culture (p = .009, 1.74-fold change); (4) when data from third-trimester samples were compared, overall differences in syndecan-1 MoM values between cases and controls were slightly larger (p = .03, 1.36- fold change), which were especially contributed to by cases with a positive blood culture (p = .023, fold change 1.79-fold change).

CONCLUSIONS

Plasma syndecan-1 concentration is higher in pregnant women and increases as a function of gestational age. Patients with acute pyelonephritis have a higher plasma concentration of syndecan-1, and this is particularly the case in the presence of bacteremia.

Relationship Between Serum Endocan Levels and Other Predictors of Endothelial Dysfunction in Obese Women

Endocan, or endothelial cell-specific molecule-1 (ESM-1), is a potential inflammatory marker implicated in endothelial dysfunction. The purpose of this study was to determine the correlation between serum endocan levels and the presence and severity of endothelial dysfunction, and the relationships with serum intracellular adhesion molecule-1 (ICAM-1), adiponectin (a marker of inflammation), high sensitivity C-reactive protein (hsCRP) levels, and carotid intima-media thickness (cIMT) in obese subjects. Serum endocan, ICAM-1, adiponectin, hsCRP levels, and cIMT were evaluated in 76 obese women (BMI > 30 kg/m2) and 53 controls (BMI < 25 kg/m2). ICAM-1 (P = .01), hs-CRP (p < 0.001), and cIMT (p < .001) were significantly higher, while adiponectin (P = .006) was significantly lower, in obese women compared with the controls. Serum endocan levels were similar between the obese (470.5 ± 171.3 pg/mL) and controls (471.9 ± 146.3 pg/mL) (P = .732). There was no correlation between serum endocan values and the endothelial dysfunction markers, hsCRP (r = -.021), ICAM-1 (r = -.054), adiponectin (r = .113), or cIMT (r = -.060) in obesity. Endocan is not a suitable marker of endothelial dysfunction in the context of obesity. More research is required to evaluate the role of endocan in the regulation of inflammatory processes in obesity.

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.

Plasma Endocan Levels in Early and Late-Onset Preeclampsia

Preeclampsia (PE) may represent an inflammatory process. Endocan (ESM-1) is a marker of endothelial inflammation. We compared plasma endocan levels between PE and control groups and between early and late-onset PE. Study design: Maternal plasma endocan levels were measured in 41 preeclampsia (PE) pregnancies - 25 early-onset (<34 weeks); 16 late-onset (≥34 weeks), and 37 non-complicated pregnancies (22 matched with early-onset PE, 15 with late onset). Results: There was no significant differences between plasma endocan levels of patients with PE and control group (468.8(IQR: 169.7)ng/L vs 462.4(IQR: 321.1)ng/L, p > 0.05), between early and late-onset PE (458.8(221.8)ng/L vs 469.8(122.6)ng/L, p > 0.05), between early-onset PE and corresponding control group (458.8(221.8)ng/L vs 506.2(1481.9)ng/L, p > 0.05), or late-onset PE and corresponding control group (469.8(122.6)ng/L vs 451.0(85.1)ng/L, p > 0.05). Conclusion: There was no significant difference between endocan levels of early or late-onset PE compared with their corresponding control groups, nor between early and late-onset preeclampsia groups.

Tumor necrosis factor alpha expression is increased in maternal microvascular endothelial cells in preeclampsia

Objective: The aim of this study was to explore the expression and effects of tumor necrosis factor alpha (TNFα) in maternal endothelial cells in preeclampsia (PE).Methods: Expression levels in primary microvascular endothelial cells (MVEC) isolated from patients with severe preeclampsia (PE) and normal pregnancies were determined by RT-qPCR with or without treatment of TNFα and inhibitors for downstream signaling.Results: PE MVEC exhibited increased basal TNFα expression. TNFα treatment increased TNFα, VCAM, and endocan expression in MVEC.Conclusion: TNFα expression is increased in PE MVEC and the treatment of these cells with exogenous TNFα modifies their gene expression.

Soluble syndecan-1 and glycosaminoglycans in preeclamptic and normotensive pregnancies

Preeclampsia, an important cause of maternal and fetal morbidity and mortality, is associated with increased sFLT1 levels and with structural and functional damage to the glycocalyx contributing to endothelial dysfunction. We investigated glycocalyx components in relation to preeclampsia in human samples. While soluble syndecan-1 and heparan sulphate were similar in plasma of preeclamptic and normotensive pregnant women, dermatan sulphate was increased and keratan sulphate decreased in preeclamptic women. Dermatan sulphate was correlated with soluble syndecan-1, and inversely correlated with blood pressure and activated partial thromboplastin time. To determine if syndecan-1 was a prerequisite for the sFlt1 induced increase in blood pressure in mice we studied the effect of sFlt1 on blood pressure and vascular contractile responses in syndecan-1 deficient and wild type male mice. The classical sFlt1 induced rise in blood pressure was absent in syndecan-1 deficient mice indicating that syndecan-1 is a prerequisite for sFlt1 induced increase in blood pressure central to preeclampsia. The results show that an interplay between syndecan-1 and dermatan sulphate contributes to sFlt1 induced blood pressure elevation in pre-eclampsia.

Maternal serum endothelial cell-specific molecule-1 level and its correlation with severity of early-onset preeclampsia

Preeclampsia (PE), the primary pathology of which is endothelial cell (EC) dysfunction, has long-lasting effects such as cardiovascular disease. Therefore, it was decided to investigate the maternal serum concentrations of EC-specific molecule-1 in patients with early-onset preeclampsia (E-PE). This study was conducted on 33 pregnant women with E-PE and 35 healthy pregnant women matched for gestational age. EC-specific molecule-1 level was measured using a commercially available enzyme-linked immunosorbent assay kit. The mean EC-specific molecule-1 concentrations were not significantly different between the groups (651.7 ± 632.2 pg/mL vs. 425.9 ± 263.0 pg/mL, p=.056). Among women with E-PE, the median EC-specific molecule-1 concentration did not differ significantly by disease severity (p=.115). EC-specific molecule-1 is not involved in the pathogenesis of E-PE. However, some studies in the literature report that EC-specific molecule-1 concentrations increased during the diagnosis of PE. Therefore, well-designed studies with a large sample are needed in cases of E-PE.Impact StatementWhat is already known on this subject? There is an increased risk of cardiovascular disease (CVD) in early-onset preeclampsia (E-PE) which is linked with endothelial dysfunction. Endothelial cell (EC)-specific molecule-1 stands out as an important marker in EC dysfunction related conditions such as preeclampsia.What the results of this study add? This study showed that EC-specific molecule-1 is not associated with the CVDs risk linked with endothelial dysfunction in E-PE. Additionally, there was also no significant relationship was detected between the severity of E-PE and EC-specific molecule-1 concentrations.What the implications are of these findings for clinical practice and/or further research? Endothelial cell-specific molecule-1 is not involved in the pathogenesis of E-PE. Moreover, advantageous and easy-to-measure markers are needed in larger sample studies to better understand the aetiology of E-PE.

Endothelial cell-specific-molecule-1 (endocan) levels in women with premature ovarian insufficiency: a prospective comparative study

There is an increased risk of cardiovascular disease in women with premature ovarian insufficiency (POI). A relationship between cardiovascular disease and endocan levels has been shown. Endocan is a marker that is prominent in many diseases caused by endothelial dysfunction and can be measured in the blood. POI is also associated with endothelial dysfunction. The causes of POI include chromosomal and genetic defects, autoimmune processes, chemotherapy, radiation, infections and surgery, but many are unidentified (idiopathic). This study aimed to evaluate serum endocan levels in women with idiopathic POI. The blood for analysis was obtained at the early follicular phase of the menstrual cycle and endocan levels were measured using a commercially available enzyme-linked immunosorbent assay kit. There were 38 patients with idiopathic POI in the study group and 39 healthy subjects in the control group. The median ages of the women were not significantly different between the groups 34 [7] years vs. 34 [7] years, respectively (p = .862). The median endocan level was not different in the POI and control group 769 [727] vs. 1077 [403] pg/mL, respectively (p = .603). Endocan is not associated with the cardiovascular diseases risk linked with endothelial dysfunction in idiopathic POI. Clinical trial number: NCT03932877 (Clinicaltrials.gov)IMPACT STATEMENTWhat is already known on this subject? There is an increased risk of cardiovascular disease in premature ovarian insufficiency (POI) due to the decreased level of oestrogen, which is linked with endothelial dysfunction.What do the results of this study add? This study showed that endocan is not associated with the cardiovascular disease risk linked with endothelial dysfunction in idiopathic POI.What are the implications of these findings for clinical practice and/or further research? A marker to be used to predict the risk of cardiovascular disease in patients with POI could facilitate in improving the quality of life of these patients. Moreover, advantageous and easy-to-measure markers are needed in larger sample studies to better understand the cardiovascular diseases risk in POI.

Endocan: A novel biomarker for risk stratification, prognosis and therapeutic monitoring in human cardiovascular and renal diseases

The vascular endothelium is localized at the interface between the blood and surrounding tissues, playing a pivotal role in the maintenance of tissue-fluid homeostasis and in the regulation of host defense, inflammation, vascular tone and remodeling, angiogenesis and haemostasis. The dysfunctional endothelium was shown to be implicated in the pathophysiology of several endothelial-dependent disorders, such as arterial hypertension, coronary artery disease, heart failure and chronic kidney disease, in which it is an early predictor of cardiovascular events. Endocan is a soluble dermatan sulphate proteoglycan mainly secreted by the activated endothelium. It is upregulated by several proinflammatory cytokines and proangiogenic factors and may itself contribute to the inflammatory status. In addition of being a surrogate marker of inflammation and endothelial dysfunction, it seems to be involved in the regulation of several proliferative and neovascularization processes. Therefore, its utility as a biomarker in a wide spectrum of diseases has been increasingly explored. Here, we review the current evidence concerning the role of endocan in several human cardiovascular and renal diseases, where it seems to be a promising biomarker for risk stratification, prognosis and therapeutic monitoring.

Can Endothelial Glycocalyx Be a Major Morphological Substrate in Pre-Eclampsia?

Today pre-eclampsia (PE) is considered as a disease of various theories; still all of them agree that endothelial dysfunction is the leading pathogenic factor. Endothelial dysfunction is a sequence of permanent immune activation, resulting in the change of both the phenotype and the functions of an endothelial cell and of the extracellular layer associated with the cell membrane—endothelial glycocalyx (eGC). Numerous studies demonstrate that eGC mediates and regulates the key functions of endothelial cells including regulation of vascular tone and thromboresistance; and these functions are disrupted during PE. Taking into account that eGC and its components undergo alterations under pathological conditions leading to endothelial activation, it is supposed that eGC plays a certain role in pathogenesis of PE. Envisaging the eGC damage as a key factor of PE, might be a new approach to prevention, treatment, and rehabilitation of patients with PE. This approach could include the development of drugs protecting eGC and promoting regeneration of this structure. Since the issue of PE is far from being solved, any effort in this direction might be valuable.

Maternal plasma endocan levels in intrauterine growth restriction

Objectives: Intrauterine growth restriction (IUGR) is diagnosed when the estimated fetal weight remains below the 10th percentile of gestational age based on pathological restriction of growth and/or accompanying Doppler abnormalities. Endothelial dysfunction is a common pathogenetic pathway underlying IUGR etiology. Endocan (ESM-1) is a novel marker of endothelial dysfunction and inflammation found in the maternal circulation. This study was designed to compare plasma endocan levels between pregnancies complicated with IUGR and a control group.Study design: Forty-four pregnancies complicated with IUGR and 47 healthy pregnancies were included. Maternal plasma endocan levels were detected by ELISA. Parametric data was studied by Student's t-test. Mann-Whitney U-test was used in analyzing non-parametric data. Categorical variables underwent chi-square test. ROC analysis was performed to define the cutoff value of endocan in detecting IUGR. Spearman correlation test was performed.Results: Maternal plasma endocan level varied significantly between IUGR and healthy pregnancies and was 1.8 fold higher in the IUGR group (793.0 (IQR:544.4-1896.0) ng/L vs. 441.8 (IQR: 408.3-512.4) ng/L, p < .001). There was a weak negative correlation between endocan level and 5th and 10th minute APGAR Scores (r =  -0.256; p = .015 and r =  -0.215; p = .042, respectively), a weak positive correlation with umbilical artery pulsatility index, and a moderate negative correlation with cerebroplacental ratio (r  =  0.394; p < .001 and r =  -0.459; p < .001, respectively).Conclusions: There was a significant difference between endocan levels of IUGR and healthy pregnancies. Further studies might be designed to investigate the performance of endocan in predicting neonatal outcomes for pregnancies complicated with IUGR.

Amniotic fluid concentrations of soluble endoglin and endothelial cell-specific molecule-1 in pregnancies complicated with neural tube defects

Objective To determine the concentrations of soluble endoglin (sCD105) and endothelial cell-specific molecule-1 (ESM-1) in the amniotic fluid (AF) of pregnant women, and to investigate the relationship between these concentrations and neural tube defects (NTDs). Methods AF concentrations of sCD105 and ESM-1 were measured in the study group, which included 60 pregnant women complicated with NTDs, and 64 pregnant women with unaffected healthy fetuses (control group). The AF concentrations of sCD105 and ESM-1 in both groups were measured using enzyme-linked immunosorbent assay and compared. Results There were no significant differences in terms of the mean AF concentrations of sCD105 and ESM-1 between the groups (P=0.141, P=0.084, respectively). There was a significant difference between the AF sCD105 concentrations in those with gestational age <24 weeks (n=101) and ≥24 weeks (n=23) (X̅<24=76.35±126.62 vs. X≥24=39.87±58.32, P=0.041). AF ESM-1 concentrations were found to be statistically significant in the gestational age <22 weeks (n=90) and ≥22 weeks (n=34) groups (X̅<22=135.91±19.26 vs. X̅≥22=148.56±46.85, P=0.035). A positive and low-level relation at a statistically significant level was determined between the gestational age and AF ESM-1 concentration in the study group (r=0.257; P=0.048). Conclusion AF concentrations of sCD105 and ESM-1 were not associated with the development of NTDs. Unlike studies that reported that ESM-1 concentrations decreased in maternal plasma with increased gestational age, we determined an increase that was proportionate to gestational age in AF.

Circulating endocan and preeclampsia: a meta-analysis

Background: Endocan, a novel protein involved in inflammation and endothelial dysfunction, has been suggested to be related to preeclampsia, although the results of previous studies were not consistent. The aim of the study was to evaluate the potential difference of circulating endocan in women with preeclampsia and those with normal pregnancy.

Methods: Matched case–control studies evaluating the difference of circulating endocan between women with preeclampsia and those with normal pregnancy were identified via systematic search of PubMed and Embase databases. A random-effect model or a fixed-effect model was used to pool the results according to the heterogeneity. Subgroup analysis was performed to evaluate whether the timing of preeclampsia onset affected the outcome.

Results: Overall, eight matched case–control studies, including 451 women with preeclampsia and 442 women with normal pregnancy were included. Significant heterogeneity was detected among the included studies (P for Cochrane’s Q test = 0.006, I² = 65%). Meta-analysis with a random-effect model showed that women with preeclampsia had significantly higher circulating level of endocan compared with women with normal pregnancy (standardized mean difference = 0.37, 95% confidence interval: 0.13–0.62, P = 0.003). Subsequent subgroup analyses showed that the difference of circulating endocan between women with early onset preeclampsia and those with normal pregnancy was not statistically different from that between women with late-onset preeclampsia and those with normal pregnancy (P for subgroup difference = 0.81).

Conclusions: Women with preeclampsia have higher circulating endocan than those with normal pregnancy.

The utility of maternal serum endocan level to predict preterm delivery within seven days in patients with threatened preterm labor

OBJECTIVE

The aim of the current study was to determine serum endocan levels in patients with threatened preterm labor and to assign whether endocan levels in patients with true preterm labor who give birth within 7 days differ from those of false preterm labor and uncomplicated pregnancy.

MATERIALS AND METHODS

This cross-sectional study was conducted on 58 patients diagnosed with threatened preterm labor and 31 healthy pregnant women matched for gestational age. Patients with threatened preterm labor were divided into two groups; preterm delivery (28) and term delivery (30) groups. Maternal serum endocan levels were measured with the use of an enzyme-linked immunosorbent assay kit.

RESULTS

The median serum endocan level (pg/mL) in patients with threatened preterm labor was significantly higher than that of women with uncomplicated pregnancies (725, IQR 619-823 versus 310, IQR 218-423; p < .001 Figure 1). Subgroup analysis performed among threatened preterm labor group revealed that median serum endocan level (pg/mL) in preterm delivery group was higher compared with the other two groups (preterm 823, IQR 718-905 versus term 637, IQR 590-729 p < .001 and preterm 823, IQR 718-905 versus control 310, IQR 218-423 p < .001). The threshold value of maternal serum endocan level for predicting delivery within 7 days after admission was calculated 655 pg/mL, (the area under curve was 0.934, 95% CI 0.88-0.98, p < .001) with 85.7% sensitivity and 78.7% specificity. The mean cervical length measurement was significantly higher in the control group (p < .001); there was no significant difference in cervical length between the term and preterm delivery groups. Maternal characteristics including age, BMI, gravidity, gestational age at blood sampling, CRP and Hb levels were not significantly different between groups (p > .05).

CONCLUSIONS

The maternal serum endocan level may be a useful marker to define high risk group for preterm delivery in patients with threatened preterm labor and similar cervical length measures.

Maternal serum endocan concentrations are elevated in patients with preterm premature rupture of membranes

Objectives To evaluate the maternal serum endocan levels in pregnant women complicated by preterm premature rupture of membranes (PPROM) and to compare the results with healthy pregnancies. Methods This cohort study included 31 pregnant women with PPROM and 34 gestational age-matched healthy subjects in the third trimester of pregnancy. The blood for analysis was obtained on the day of diagnosis and serum endocan levels were measured using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. The pregnant women were observed until the delivery and perinatal data were noted. Results No significant differences regarding maternal age, body mass index, gravidity, parity and gestational age at sampling were observed (P > 0.05). Mean serum endocan level was significantly higher in the PPROM group than in healthy controls (1490 ± 632 pg/mL vs. 972 ± 586 pg/mL, respectively; P: 0.001). Serum endocan concentration was positively correlated with C-reactive protein (CRP) (r = 0.754, P < 0.001) and white blood cells count (WBC) (r = 0.712, P:0.001). The receiver operating characteristic (ROC) curve analysis showed that endocan with a cut-off point of 1198 ng/dL indicated women with PPROM with sensitivity of 64.5% and specificity of 35.1% (area under curve 0.731, confidence interval 0.61-0.85). Conclusion Serum endocan level was significantly elevated in the PPROM patients than in healthy controls. The endocan level may be a useful indicator of endothelial dysfunction/inflammation in PPROM cases.

Endocan Is an Independent Predictor of Heart Failure-Related Mortality and Hospitalizations in Patients with Chronic Stable Heart Failure

Background

Heart failure (HF) is characterized by unfavorable prognosis. Disease trajectory of HF, however, may vary, and risk assessment of patients remains elusive. In our study, we sought to determine the prognostic impact of endocan—a novel biomarker of endothelial dysfunction and low-grade inflammation—in patients with heart failure.

Methods

In outpatients with chronic HF, baseline values of endocan were determined and clinical follow-up for a minimum of 18 months obtained. A multivariate Cox proportional hazard model was built for HF-related death or hospitalization requiring inotropic support.

Results

A total of 120 patients (mean age 71 years, 64% male, mean LVEF 36%) were included. During a mean follow-up of 656 ± 109 days, 50 patients (41.6%) experienced an event. On Cox multivariate analysis, endocan values emerged as an independent predictor of HF prognosis (HR, 1.471 CI 95% 1.183-1.829, p = 0.001, for each 1 ng/mL increase) even after adjustment for age, gender, HF etiology, LVEF, NYHA class, NT-proBNP, and exercise tolerance.

Conclusions

Endocan is an independent predictor of HF-related events in chronic HF individuals and represents a promising tool for risk assessment of HF patients.

Endocan expression in placenta of women with hypertension

AIM

The aim of our study was to determine the endocan-1 expression in placenta of hypertensive women, and its association with maternal and fetal outcomes.

METHODS

This was a cross-sectional study consisted of 21 pregnant women with hypertension and 23 without hypertension. The gestational age ranged from 28 to 39 weeks (hypertensive) and 32 to 40 weeks (normotensive). The paraffin embedded formalin fixed placenta tissue blocks were retrieved from the pathology archives. Endocan immunohistochemistry was performed on tissue sections of full thickness and maternal surface of the placenta. The endocan expression was determined in fetal endothelial cells, maternal endothelial cells, cytotrophoblasts, syncytiotrophoblasts and decidual cells. The differences in endocan expression in placenta between hypertensive and normotensive subjects were evaluated by Pearson chi-square test and t-test were used in the statistical analysis.

RESULTS

The endocan expression was significantly higher in fetal endothelial cells (P < 0.001), maternal endothelial cells (P = 0.003) and decidual cells (P < 0.001) in the placenta of women with hypertension. When comparing positive and negative endocan expression in maternal outcomes, endocan was associated with the development of pre-eclampsia (P = 0.03). Also, a positive endocan expression was associated with low birthweight (P = 0.001) and prematurity (P = 0.005) in the fetal outcomes.

CONCLUSION

This study showed endocan is highly expressed in fetal endothelial cells, maternal endothelial cells and decidual cells in placenta of hypertensive women. In addition, its expression was associated with poorer maternal and fetal outcomes. These findings suggest endocan may play an important role in the progression of hypertension in pregnancy.

Serum endocan concentration and its correlation with severity of hypertensive disorders in pregnancy

Introduction: Endocan plays a role in the development of vascular tissue in health and disease and is an indicator of endothelial cells activation and angiogenesis.Objective: The aim of this study was to investigate the relationship between endocan serum levels and various types of hypertensive disorders in pregnant women.Patients and methods: We created three study groups (preeclampsia [n = 60], chronic hypertension [n = 39], gestational hypertension [n = 58]) and the control group consisting of 59 healthy pregnant women. The endocan serum concentration was assessed using commercially available ELISA kit.Results: There were no statistically significant differences in endocan serum levels (pg/mL) in each study group compared to controls. The multiple regression did not reveal significant differences between endocan levels in each study group after adjustment for prepregnancy BMI. We did not find any significant correlations between the endocan serum level and patients' age, gestational age (GA) at sample collection, prepregnancy BMI, systolic blood pressure, diastolic blood pressure, and 24-hour urinary protein excretion in each analyzed group. Moreover, in the preeclamptic participants, we did not observe a significant relationship between the endocan concentration and the features indicating the severity of the disease other than elevated blood pressure. There were no differences in endocan serum level in preeclampsia subgroups: early-onset versus late-onset and mild versus severe preeclampsia.Conclusions: Endocan is not involved in the pathogenesis of hypertensive disorders in pregnant women and could not be regarded as a marker of endothelial dysfunction in these cases.

Molecular determinants of microvascular dysfunction in hypertensive pregnancy and preeclampsia

Preeclampsia is a pregnancy-related disorder characterized by hypertension and often fetal intrauterine growth restriction, but the underlying mechanisms are unclear. Defective placentation and apoptosis of invasive cytotrophoblasts cause inadequate remodeling of spiral arteries, placental ischemia, and reduced uterine perfusion pressure (RUPP). RUPP causes imbalance between the anti-angiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the pro-angiogenic vascular endothelial growth factor and placental growth factor, and stimulates the release of proinflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors target the vascular endothelium, smooth muscle and various components of the extracellular matrix. Generalized endotheliosis in systemic, renal, cerebral, and hepatic vessels causes decreases in endothelium-derived vasodilators such as nitric oxide, prostacyclin and hyperpolarization factor, and increases in vasoconstrictors such as endothelin-1 and thromboxane A2. Enhanced mechanisms of vascular smooth muscle contraction, such as intracellular Ca2+ , protein kinase C, and Rho-kinase cause further increases in vasoconstriction. Changes in matrix metalloproteinases and extracellular matrix cause inadequate vascular remodeling and increased arterial stiffening, leading to further increases in vascular resistance and hypertension. Therapeutic options are currently limited, but understanding the molecular determinants of microvascular dysfunction could help in the design of new approaches for the prediction and management of preeclampsia.

Maternal Serum Endocan Concentration in Pregnancies Complicated by Intrauterine Growth Restriction

OBJECTIVES

Endocan plays a role in the development of vascular tissue in health and disease and is an indicator of endothelial cells activation and angiogenesis. Therefore, this study aimed to investigate the relationship between maternal endocan serum level and intrauterine growth restriction (IUGR) as well as ultrasound Doppler flow measurements indicating placental insufficiency.

METHODS

This study included a group of women with IUGR (n = 37) and a group of healthy pregnant women (controls, n = 37). The endocan serum concentrations were assessed using commercially available enzyme-linked immunosorbent assay kit. Every woman underwent an ultrasound examination with Doppler flow measurements of the uterine arteries, umbilical vessels, and fetal middle cerebral artery. We used the cerebroplacental ratio (CPR) to determine placental insufficiency.

RESULTS

We found significant differences in median (interquartile) endocan serum level (pg/mL) between study and control groups (464 [374-532] vs 339 [189-496], respectively; P < .001). The endocan serum level correlated neither with umbilical cord blood gases nor with Apgar score. Ultrasound Doppler findings revealed significant differences in middle cerebral artery pulsatility index (PI), umbilical artery PI, CPR, as well as mean uterine arteries PI between IUGR group and controls. In the study group, we found significant correlations between the serum endocan and CPR ( R = 0.56, P < .001) as well as between serum endocan and mean uterine arteries PI ( R = 0.46, P = .006).

CONCLUSION

Endocan is likely involved in the pathogenesis of IUGR in pregnant women and possibly is a useful marker of endothelial dysfunction in these cases.

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

Metformin, the aspirin of the 21st century: its role in gestational diabetes mellitus, prevention of preeclampsia and cancer, and the promotion of longevity

Metformin is everywhere. Originally introduced in clinical practice as an antidiabetic agent, its role as a therapeutic agent is expanding to include treatment of prediabetes mellitus, gestational diabetes mellitus, and polycystic ovarian disease; more recently, experimental studies and observations in randomized clinical trials suggest that metformin could have a place in the treatment or prevention of preeclampsia. This article provides a brief overview of the history of metformin in the treatment of diabetes mellitus and reviews the results of metaanalyses of metformin in gestational diabetes mellitus as well as the treatment of obese, non-diabetic, pregnant women to prevent macrosomia. We highlight the results of a randomized clinical trial in which metformin administration in early pregnancy did not reduce the frequency of large-for-gestational-age infants (the primary endpoint) but did decrease the frequency of preeclampsia (a secondary endpoint). The mechanisms by which metformin may prevent preeclampsia include a reduction in the production of antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 and soluble endoglin) and the improvement of endothelial dysfunction, probably through an effect on the mitochondria. Another potential mechanism whereby metformin may play a role in the prevention of preeclampsia is its ability to modify cellular homeostasis and energy disposition, mediated by rapamycin, a mechanistic target. Metformin has a molecular weight of 129 Daltons and therefore readily crosses the placenta. There is considerable evidence to suggest that this agent is safe during pregnancy. New literature on the role of metformin as a chemotherapeutic adjuvant in the prevention of cancer and in prolonging life and protecting against aging is reviewed briefly. Herein, we discuss the mechanisms of action and potential benefits of metformin.

Matrix Metalloproteinases in Normal Pregnancy and Preeclampsia

Normal pregnancy is associated with marked hemodynamic and uterine changes that allow adequate uteroplacental blood flow and uterine expansion for the growing fetus. These pregnancy-associated changes involve significant uteroplacental and vascular remodeling. Matrix metalloproteinases (MMPs) are important regulators of vascular and uterine remodeling. Increases in MMP-2 and MMP-9 have been implicated in vasodilation, placentation, and uterine expansion during normal pregnancy. The increases in MMPs could be induced by the increased production of estrogen and progesterone during pregnancy. MMP expression/activity may be altered during complications of pregnancy. Decreased vascular MMP-2 and MMP-9 may lead to decreased vasodilation, increased vasoconstriction, hypertensive pregnancy, and preeclampsia. Abnormal expression of uteroplacental integrins, cytokines, and MMPs may lead to decreased maternal tolerance, apoptosis of invasive trophoblast cells, inadequate remodeling of spiral arteries, and reduced uterine perfusion pressure (RUPP). RUPP may cause imbalance between the antiangiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the proangiogenic vascular endothelial growth factor and placental growth factor, or stimulate the release of inflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors could target MMPs in the extracellular matrix as well as endothelial and vascular smooth muscle cells, causing generalized vascular dysfunction, increased vasoconstriction and hypertension in pregnancy. MMP activity can also be altered by endogenous tissue inhibitors of metalloproteinases (TIMPs) and changes in the MMP/TIMP ratio. In addition to their vascular effects, decreases in expression/activity of MMP-2 and MMP-9 in the uterus could impede uterine growth and expansion and lead to premature labor. Understanding the role of MMPs in uteroplacental and vascular remodeling and function could help design new approaches for prediction and management of preeclampsia and premature labor.

Mechanisms of Endothelial Dysfunction in Hypertensive Pregnancy and Preeclampsia

Preeclampsia is a pregnancy-related disorder characterized by hypertension and could lead to maternal and fetal morbidity and mortality. Although the causative factors and pathophysiological mechanisms are unclear, endothelial dysfunction is a major hallmark of preeclampsia. Clinical tests and experimental research have suggested that generalized endotheliosis in the systemic, renal, cerebral, and hepatic circulation could decrease endothelium-derived vasodilators such as nitric oxide, prostacyclin, and hyperpolarization factor and increase vasoconstrictors such as endothelin-1 and thromboxane A2, leading to increased vasoconstriction, hypertension, and other manifestation of preeclampsia. In search for the upstream mechanisms that could cause endothelial dysfunction, certain genetic, demographic, and environmental risk factors have been suggested to cause abnormal expression of uteroplacental integrins, cytokines, and matrix metalloproteinases, leading to decreased maternal tolerance, apoptosis of invasive trophoblast cells, inadequate spiral arteries remodeling, reduced uterine perfusion pressure (RUPP), and placental ischemia/hypoxia. RUPP may cause imbalance between the antiangiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the proangiogenic factors vascular endothelial growth factor and placental growth factor, or stimulate the release of other circulating bioactive factors such as inflammatory cytokines, hypoxia-inducible factor-1, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors could then target endothelial cells and cause generalized endothelial dysfunction. Therapeutic options are currently limited, but understanding the factors involved in endothelial dysfunction could help design new approaches for prediction and management of preeclampsia.

Endocan of the maternal placenta tissue is increased in pre-eclampsia

PURPOSE

Pre-eclampsia (PE) is associated with intravascular inflammation and endothelial dysfunction. Interestingly, endocan plays a predominant role in the vascular inflammation and is considered as a biomarker of endothelial dysfunction. The aim of this study was to explore whether the endocan levels in serum and placenta were different between pregnant women with PE and the normal pregnancies.

METHODS

Total 22 patients, including 10 normal pregnant women and 12 patients with PE, were included in this study. Immunohistochemistry was used to evaluate the location of endocan. Then, the mRNA and protein levels of endocan in placenta were detected using qRT-PCR and western blotting. Serum endocan concentration was measured by ELISA.

RESULTS

Endocan protein was present in the human placenta, and the mRNA and protein levels of placenta tissues were elevated (P < 0.05) in the normal pregnancy with third trimester than those with first trimester. Furthermore, the expression of endocan mRNA and protein were increased in the placenta tissues of PE compared with in the normal pregnancy (P < 0.05); however, the endocan concentration of maternal serum did not have significant differences.

CONCLUSION

Endocan may play a role in the progression of pregnancy and has a potential to be a new marker for the detective of PE.

Serum levels of endocan correlate with the presence and severity of pre-eclampsia

BACKGROUND

Endocan, a cysteine-rich dermatan sulfate proteoglycan expressed by endothelial cells, is seemed to be a new biomarker for endothelial dysfunction. Pre-eclampsia (PE) is characterized by the new onset of hypertension, proteinuria after 20 weeks of gestation, placental vascular remodeling, systemic vascular inflammation and endothelial dysfunction. The aim of this study was to investigate the relationship of PE and its severity with serum endocan levels.

METHODS

A cross-sectional study was performed. Serum was collected from women with PE and normotensive controls. Serum endocan and tumor necrosis factor alpha (TNF-α) concentrations were measured by a specific enzyme linked immunosorbent assay.

RESULTS

Patients with PE had significantly higher median (interquartile range) endocan and mean TNF-α concentrations than controls [20.04 (12.26) ng/mL vs 15.55 (6.19) ng/mL, p < 0.001 for endocan; 26.49 ± 12.14 pg/mL vs 14.62 ± 5.61 pg/mL, p < 0.001 for TNF-α; respectively]. Serum endocan concentrations were positively correlated with systolic blood pressure (r = 0.618, p < 0.001), diastolic blood pressure (r = 0.608, p < 0.001), the amount of 24-h proteinuria (r = 0.786, p < 0.001) and TNF-α (r = 0.474, p < 0.001) in women with PE. In subgroup analysis, patients with severe PE had significantly higher endocan concentrations than those with mild PE. Receiver operating characteristic analysis of endocan was used to identify the patients with PE and also discriminating between mild and severe PE.

CONCLUSION

Serum endocan concentrations were significantly elevated in women with PE versus normotensive controls, and concentrations seem to be associated with the severity of the disease.

Pulsatility index in combination with biomarkers or mean arterial pressure for the prediction of pre-eclampsia: Systematic literature review and meta-analysis

INTRODUCTION

Our objective was to perform a meta-analysis examining the sensitivity of pulsatility index (PI) and various biomarkers and PI and mean arterial pressure (MAP) for the prediction of pre-eclampsia.

MATERIAL AND METHODS

PubMed, CENTRAL, and Embase databases were searched from inception until 8 May 2014 using combinations of the search terms: pre-eclampsia, ultrasonography, pregnancy, biomarker, mean arterial pressure, placental protein 13, pregnancy-associated plasma protein-A, placental growth factor, activin A, inhibin A, pulsatility index. The pooled sensitivity of PI + biomarkers and PI + MAP were calculated, and reported with corresponding 95% confidence intervals (CIs).

RESULTS

Fifteen studies were included in the meta-analysis. The pooled sensitivity of all biomarkers for the prediction of pre-eclampsia was 0.669 (95% CI 0.610-0.723), for the prediction of early-onset pre-eclampsia was 0.830 (95% CI 0.794-0.861), and for the prediction of late-onset pre-eclampsia was 0.564 (95% CI 0.499-0.627). Similarly, the predictive ability of PI + MAP for early-onset pre-eclampsia was good (sensitivity 0.894), while that for late-onset was poor (sensitivity 0.570).

CONCLUSION

The combination of PI and different biomarkers or MAP exhibits a good predictive ability for early-onset pre-eclampsia, and poor predictive ability for late-onset pre-eclampsia.