Endocan: a novel circulating proteoglycan

A low testosterone level impairs erectile function by increasing endocan expression in rat penile corpus cavernosum

BACKGROUND

The mechanism by which a state of low testosterone leads to erectile dysfunction (ED) has not been determined. Endocan is a novel marker of endothelial function. However, whether endocan is involved in the regulation of erectile function under low testosterone levels remains unclear.

AIM

In this study we sought to determine whether a low-testosterone state inhibits erectile function by regulating endocan expression in the endothelial cells of the rat penile corpus cavernosum.

METHODS

Thirty-six male Sprague-Dawley rats aged 8 weeks were randomly assigned to 6 groups (n = 6 per group) as follows: (1) control, (2) castration, (3) castration + testosterone treatment (treated with 3 mg/kg testosterone propionate per 2 days), (4) control + transfection (4 weeks after castration, injected with lentiviral vector (1 × 108 transduction units/mL, 10 μL), (5) castration + transfection, or (6) castration + empty transfection. One week after the injection, we measured the maximal intracavernous pressure/mean arterial pressure (ICPmax/MAP), serum testosterone and nitric oxide (NO) levels, and the expression of endocan, phospho-endothelial NO synthase (p-eNOS), eNOS, phospho-protein kinase B (p-AKT), and AKT in the rat penile corpus cavernosum.

OUTCOMES

Under a low-androgen state, the expression of endocan in the rat penile corpus cavernosum was significantly increased, which inhibited the AKT/eNOS/NO signaling pathway and resulted in ED.

RESULTS

In the castration group, the expression of endocan in the rat penile corpus cavernosum was significantly higher than that in the control group (P < .05). Additionally, the levels of p-AKT/AKT, p-eNOS/eNOS, and NO in the rat penile corpus cavernosum and ICPmax/MAP were significantly lower in the castration group than in the control group (P < .05). In the castration + transfection group compared with the castration group there was a significant decrease in the expression of endocan (P < .05) and an increase in the ratios of p-AKT/AKT, p-eNOS/eNOS, and ICPmax/MAP (P < .05) in the rat penile corpus cavernosum.

CLINICAL IMPLICATIONS

Downregulating the expression of endocan in the penile corpus cavernosum may be a feasible approach for treating ED caused by hypoandrogenism.

STRENGTHS AND LIMITATIONS

The results of this study indicte that endocan may affect NO levels and erectile function through multiple signaling pathways, but further experiments are needed to clarify the relationship between endocan and androgens.

CONCLUSION

A low-testosterone state inhibits the AKT/eNOS/NO signaling pathway by increasing the expression of endocan in the rat penile corpus cavernosum and impairing erectile function in rats. Decreasing the expression of endocan in the penile corpus cavernosum can improve erectile function in rats with low testosterone levels.

Relationship between angiogenesis biomarker endocan and apolipoproteins in patients with acute myocardial infarction

Aim: In the current study, serum levels of endocan in patients attended with ST-elevation myocardial infarction, as well as the possible correlation with apolipoprotein-A1 (APO-A1) and APO-B were investigated. Materials & methods: In 80 men, endocan, cTnI, APO-A1, and APO-B levels were measured. Finally, the correlation of endocan with APO-A1, APO-B, and APO-B/ APO-A1 ratio was assessed. Results: Significant changes in APO-A1, APO-B, endocan levels, and APO-B/APO-A1 ratio were found in acute myocardial infarction cases compared with the control arm (p < 0.05). In addition, our finding showed a significant correlation between APO-B and endocan levels, but not APO-A. Conclusion: High endocan level is an independent indicator of endothelial dysfunction and ischemic cardiovascular conditions, which could be related to APO-B.

Endocan: A biomarker for endothelial dysfunction and inflammation, linking maternal obesity and pediatric obesity in a cohort of preterm neonates

OBJECTIVES

Numerous animal and epidemiologic studies have demonstrated a positive association between maternal obesity in pregnancy and obesity in offspring. The biologic mechanisms of this association remain under investigation. One proposed mechanism includes fetoplacental endothelial dysfunction secondary to inflammation. Endocan is a relatively new biomarker for endothelial dysfunction and inflammation. Our objectives were to examine (1) the association between maternal obesity and neonatal serum endocan at birth, and (2) the association between neonatal serum endocan at birth and pediatric obesity at 24-36 months of age.

STUDY DESIGN

This was a secondary analysis of a prospective cohort of neonates born < 33 weeks gestation. Serum endocan was collected within 48 hours of birth. Serum endocan levels were compared in neonates born to obese mothers vs. those born to non-obese mothers. BMI data were retrospectively collected from cohort neonates between 24 and 36 months of age.

RESULTS

The analysis included 120 mother/neonate dyads. Neonates born to obese mothers had higher median serum endocan at birth compared to neonates born to non-obese mothers (299 ng/L [205-586] vs. 251 ng/L [164-339], p = 0.045). In a linear regression modeled on neonatal serum endocan level, maternal obesity had a statistically significant positive association (p = 0.021). Higher mean serum endocan level at birth was associated with pediatric obesity between 24 and 36 months (obese vs. non-obese offspring; 574 ng/L (222) vs. 321 ng/L (166), p = 0.005).

CONCLUSIONS

In our cohort of preterm neonates, elevated serum endocan at birth was associated with both maternal obesity and downstream pediatric obesity. More research is needed to understand intergenerational transmission of obesity. A large focus has been on epigenetic modification. Endothelial dysfunction and inflammation may play important roles in these pathways. Effective biomarkers, including endocan, may also serve as intermediate outcomes in future pregnancy research.

Effect of nano-curcumin supplementation on angina status, and traditional and novel cardiovascular risk factors in overweight or obese patients with coronary slow flow phenomenon: a randomized double-blind placebo-controlled clinical trial

BACKGROUND

Cardiovascular events and poor quality of life are frequently observed in patients with coronary slow flow phenomenon (CSFP). This trial evaluated the effect of nano-curcumin supplement containing curcuminoids, as multifunctional nutraceuticals, on angina status, and some traditional and novel cardiovascular risk factors in overweight or obese patients with CSFP.

METHODS

In this double-blind, randomized, placebo-controlled clinical trial, 42 overweight or obese patients with CSFP received either 80 mg/day of nano-curcumin or placebo for 12 weeks. Seattle angina questionnaire (SAQ) as a clinical measure of angina status, circulating endocan, adropin, homocysteine, lipid profile, and the novel scores of visceral adiposity index (VAI) and waist-triglyceride index (WTI) were assessed before and after the intervention. The independent samples t-test, Mann-Whitney test, analysis of covariance, Chi-square, and Fisher's exact tests were used where appropriate.

RESULTS

All domains of SAQ including physical limitation, angina stability, angina frequency-severity, treatment satisfaction, and disease perception and quality of life improved significantly in the nano-curcumin compared with the placebo group. No significant changes were observed in serum endocan, adropin, and homocysteine following the intervention. Triglycerides, triglyceride/high-density lipoprotein cholesterol ratio, WTI and VAI values improved significantly only within the nano-curcumin group.

CONCLUSIONS

Supplementation with 80 mg/day nano-curcumin (containing curcuminoids) for 12 weeks significantly improved clinically important disease-specific aspects of health in patients with CSFP. Some traditional and novel cardiovascular risk factors improved significantly only compared with the baseline values, which need further investigation.

TRIAL REGISTRATION

This study was approved by the Ethics Committee of Tehran University of Medical Sciences (IR.TUMS.VCR.REC.1398.794). The study protocol was registered at Iranian Registry of Clinical Trials by IRCT20131125015536N8 registration ID at 19.06.2019.

Roles of endothelial cell specific molecule‑1 in tumor angiogenesis (Review)

Angiogenesis plays a crucial role in tumor growth and metastasis, and is heavily influenced by the tumor microenvironment (TME). Endothelial cell dysfunction is a key factor in tumor angiogenesis and is characterized by the aberrant expression of pro-angiogenic factors. Endothelial cell specific molecule-1 (ESM1), also known as endocan, is a marker of endothelial cell dysfunction. Although ESM1 is primarily expressed in normal endothelial cells, dysregulated ESM1 expression has been observed in human tumors and animal tumor models, and implicated in tumor growth, metastasis and angiogenesis. The precise role of ESM1 in tumor angiogenesis and its potential regulatory mechanisms are not yet conclusively defined. However, the aim of the present review was to explore the involvement of ESM1 in the process of tumor angiogenesis in the TME and the characteristics of neovascularization. In addition, the present review discusses the interaction between ESM1 and angiogenic factors, as well as the mechanisms through which ESM1 contributes to tumor angiogenesis. Furthermore, the reciprocal regulation between ESM1 and the TME is explored. Finally, the potential of targeting ESM1 as a therapeutic strategy for tumor angiogenesis is presented.

Systematic Review of Endocan as a Potential Biomarker of COVID-19

Since the start of the coronavirus disease 2019 (COVID-19) pandemic, several biomarkers have been proposed to assess the diagnosis and prognosis of this disease. The present systematic review evaluated endocan (a marker of endothelial cell damage) as a potential diagnostic and prognostic biomarker for COVID-19. PubMed, Scopus, Web of Science, and Embase were searched for studies comparing circulating endocan levels between COVID-19 cases and controls, and/or different severities/complications of COVID-19. Eight studies (686 individuals) were included, from which four reported significantly higher levels of endocan in COVID-19 cases compared with healthy controls. More severe disease was also associated with higher endocan levels in some of the studies. Studies reported higher endocan levels in patients who died from COVID-19, were admitted to an intensive care unit, and had COVID-19-related complications. Endocan also acted as a diagnostic and prognostic biomarker with different cut-offs. In conclusion, endocan could be a novel diagnostic and prognostic biomarker for COVID-19. Further studies with larger sample sizes are warranted to evaluate this role of endocan.

Expression of endocan and vascular endothelial growth factor and their correlation with histopathological prognostic parameters in pheochromocytoma

OBJECTIVE

Endocan and vascular endothelial growth factor (VEGF) are markers expressed in various cancer types that are highly vascular, and they have prognostic significance for these cancers. In this study, we aimed to show the expression of endocan and VEGF in pheochromocytoma tumor tissues and to evaluate their correlations with histopathological parameters.

MATERIAL AND METHODS

Thirty-eight patients who had been operated for pheochromocytoma were included in the study. As the control group, 28 subjects whose specimens contained normal adrenal medulla tissue were included. The formalin-fixed paraffin-embedded specimens of pheochromocytoma patients were evaluated for Pheochromocytoma of the Adrenal gland Scaled Score (PASS). Sections were then stained for immunohistochemical analysis. The degree of endocan and VEGF positivity was determined by the proportion of stained cells on a negative to strong scale.

RESULTS

Endocan (p < 0.001) and VEGF (p = 0.004) expressions were found to be significantly higher in the pheochromocytoma group than in the control group. In the pheochromocytoma group, total PASS score (r = 0.714; p < 0.001) and most of the PASS score components were positively correlated with the level of endocan expression. Median Ki-67 index (p = 0.010), total PASS score (p < 0.001), tumor cell spindling (p = 0.048), and nuclear pleomorphism (p = 0.030) were higher in pheochromocytoma with VEGF expression than in those without.

CONCLUSION

If our findings are supported by studies with a larger sample size, we think that endocan has the potential to be used both as a tumor marker and in predicting malignancy potential in patients with pheochromocytoma, and that the detection of VEGF expression in these tumors is also associated with an increase in malignancy potential.

The Evaluation of Serum Endocan, Interleukin-6, and CRP Levels Following Sleeve Gastrectomy

Background

The excessive accumulation of fat tissue in obesity is the source of chronic low-level inflammation and causes future dysmetabolic and cardiovascular disorders. Removal of this excessive fat tissue with the aid of bariatric surgery (BS) techniques, such as sleeve gastrectomy, may reverse adverse inflammatory outcomes. The aim of this study is to investigate the impact of sleeve gastrectomy on inflammatory markers, specifically endocan, IL-6, and CRP, in individuals with obesity.

Methods

Thirty-two patients with class 3 obesity and class 2 obesity + comorbidities were enrolled in the study. Clinical characteristics including age, comorbidity, body mass index (BMI), waist, and hip circumferences of the participants were noted before and 3 months after sleeve gastrectomy. Blood samples were collected during those periods to assess biochemical features such as serum endocan, interleukin-6 (IL-6), C-reactive peptide, fasting insulin, glycosylated hemoglobin A1c levels, and lipid panel. A statistical package program was used for the analysis of those parameters, and p<0.05 was accepted as significant at a 95.0% confidence interval.

Results

BMI reduced from 43.55±6.78 to 36.16±6.14 kg/m2 within 3 months following BS (p<0.001). Preoperative serum endocan, IL-6, and CRP levels were correlated with BMI, and in line with BMI reduction, their serum levels decreased after BS (p<0.05). HOMA-IR also reduced after BS, and both in the pre and post-BS periods correlated with BMI, IL-6, endocan, and CRP levels (p<0.05). The mean total body weight loss was 20.4% within 3 months post-BS.

Conclusion

BS techniques are effective in weight loss and reversing the inflammatory processes caused by obesity. Serum endocan, IL-6, and CRP levels are promising markers for describing obesity-related inflammation and objectively checking the alleviation of inflammation following BS.

Endocan as a marker of endothelial dysfunction in hypertension: a systematic review and meta-analysis

Hypertension is one of the foremost risk factors for cardiovascular disease and a significant cause of death worldwide. Importantly, endothelial dysfunction (ED) is one of the primary manifestations that may precede the development of hypertension. Endocan is a novel endothelial dysfunction and inflammation biomarker secreted from endothelial cells. Whether endocan may serve as a biomarker of hypertension is currently debated. This systematic review and meta-analysis aimed at linking endocan to ED in hypertensive patients. International databases, including PubMed, Scopus, Embase, and Web of Science, were systematically searched for studies investigating Endocan serum or plasma levels in hypertensive patients and healthy controls. Random effect meta-analysis was performed to calculate the standardized mean difference (SMD) and 95% confidence interval (CI). A total of 20 studies assessing the association between endocan levels and hypertension were included in which 3130 individuals with a mean age of 50.48 ± 8.45 years were assessed. Hypertensive patients presented with higher circulating endocan levels (SMD 0.91, 95% CI 0.44-1.38, p-value < 0.01) compared with healthy controls. Interestingly, our data demonstrated that removing three studies assessing endocan levels in hypertensive patients with different comorbidities or special populations resulted in the same statistically higher endocan levels (SMD 1.16, 95% CI 0.66-1.65, p-value < 0.01). Overall, this systematic review and meta-analysis indicated that in hypertensive patients circulating endocan levels are significantly elevated. Thus, suggesting endocan as an easy-to-use biomarker to detect ED in hypertension. Despite this, more research is warranted to address this potential ability specifically.

Early Diagnostic Markers of Late-Onset Neonatal Sepsis

OBJECTIVE

Early diagnosis of nosocomial infections in newborns is a great challenge, because in the initial phase of systemic infection, clinical symptoms are often non-specific, and routinely used hematological markers are not sufficiently informative. The aim of this study was to determine the potential of early inflammatory markers to diagnose late-onset neonatal sepsis-procalcitonin (PCT), interleukin 6 (IL-6), interleukin 8 (IL-8) and endocan (ESM-1).

MATERIAL AND METHODS

A prospective clinical-epidemiological study was conducted in a third-level NICU in Pleven, Bulgaria. Patients with suspected late-onset sepsis and healthy controls were tested. A sandwich ELISA method was used to measure the serum concentrations of biomarkers.

RESULTS

Sixty newborns were included, of which 35% symptomatic and infected, 33.3% symptomatic but uninfected and 31.7% asymptomatic controls. The mean values of PCT, IL-6, I/T index and PLT differ significantly in the three groups. For ESM-1, IL-8 and CRP, the difference was statistically insignificant. The best sensitivity (78%) and negative predictive value (84%) was found for IL-6. The combinations of PCT + IL-6 and PCT + IL-6+ I/T+ PLT showed very good diagnostic potential.

CONCLUSION

The introduction into the routine practice of indicators such as PCT and IL-6 may provide an opportunity to promptly optimize the diagnostic and therapeutic approach to LOS.

Endocan: A novel biomarker of endothelial dysfunction in depression?

Endocan is a proteoglycan secreted from endothelium upon endothelial damage. Since depression is associated with higher inflammation and oxidative stress to the vascular endothelium, endothelial dysfunction is prevalent and it is one of the responsible mechanisms for increased cardiovascular morbidity and mortality in depressive disorders. This study aimed to investigate endocan levels in patients with depression (either bipolar or unipolar) and healthy controls to evaluate the projected endothelial injury. We included nonsmoker patients without comorbid inflammatory conditions: 31 with Bipolar Disorder Depression (BDD), 30 with Major Depressive Disorder (MDD) and 25 healthy controls (HC). The severity of depression was assessed with the Hamilton Depression Rating Scale (HDRS). Ultimately, serum endocan levels were significantly higher in patients with BDD than in patients with MDD (p < .000) and HCs (p < .000). Also, patients with MDD had significantly higher endocan levels than HCs (p < .000). The AUC value for the endocan to differentiate patients with depression from controls was 0.990 (95% CI: 0.971-1.000; p < .001) with sensitivity and specificity of 98.4 and 100%, respectively, and an optimal cut-off value of 316.92 ng/L. Serum endocan levels showed a mild positive correlation with HDRS scores (r = 0.372, p = .039) in the BDD group but not in the MDD group (r = -0.242, p = .20). Patients with BDD had higher endocan levels than MDD; this finding, while preliminary, could be an implication of higher endothelial dysfunction in BDD.

Is maternal serum endocan level a novel marker in gestational diabetes mellitus?

AIM

To determine whether there was a significant difference between serum endocan levels of pregnant women with and without gestational diabetes mellitus (GDM).

METHODS

A total of 90 pregnant women, 45 with gestational diabetes and 45 healthy pregnant women, between 24 and 28 gestational weeks, were included in this prospective case-control study. The pregnant women were screened for gestational diabetes using a two-step protocol. Serum endocan levels were measured using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. A p-value of <0.05 was considered statistically significant.

RESULTS

Serum endocan level was significantly higher in the GDM group than in healthy controls (168.46 ± 160.6 vs. 105.66 ± 26.52 pg/mL, respectively; p < 0.001). Serum endocan concentrations were positively correlated with the results of 50 g oral glucose challenge test (GCT) (p < 0.001). Receiver operating characteristic curve analysis showed that endocan with a cut-off point of 133.9 ng/dL indicated women with GDM with a sensitivity of 55.6% and specificity of 88.9% (area under the curve [AUC]: 0.737, 95% CI: 0.634-0.824). The overall differential performance of endocan according to the GDM groups was determined as 73.7% (p < 0.001). Maternal serum endocan level was positively correlated with fasting glucose, postprandial glucose, and glycated hemoglobin (HbA1c) (p < 0.001).

CONCLUSIONS

Elevated endocan levels in gestational diabetes were correlated with fasting glucose, postprandial glucose, HbA1c, and oral glucose tolerance test (OGTT) results. Despite the low sensitivity of 55.6% and the high specificity of 88.9%, we found a high differential performance rate indicating that serum endocan levels were important for the pathophysiology of GDM and should be investigated for the possibility of being a novel marker in larger populations.

High circulating endocan in chronic kidney disease? A systematic review and meta-analysis

BACKGROUND

Chronic kidney disease (CKD) is one of the leading causes of morbidity and mortality worldwide. Endothelial dysfunction has been suggested to be involved in the pathophysiology of CKD. Endocan, as an endothelial factor, has been shown to increase in several diseases. The current systematic review and meta-analysis was performed with the aim of determining the association between endocan levels and CKD.

METHODS

Four international databases, including PubMed, Embase, Scopus, and Web of Science were searched for relevant studies. Afterward, screening and extraction of data were performed. We conducted a random-effect meta-analysis to calculate the standardized mean difference (SMD) and 95% confidence interval (CI) to compare circulating endocan levels between patients with CKD (including patients undergoing hemodialysis) and healthy controls. Subgroup analysis based on the specimen in which endocan was measured (serum or plasma) was also performed.

RESULTS

After screening by title/abstract and full-text review by the authors, 20 studies were included. Meta-analysis revealed that serum endocan is higher in CKD patients compared to healthy controls (SMD 1.34, 95% CI 0.20 to 2.48, p-value<0.01). This higher endocan level was also observed in the subgroup of studies that measured plasma endocan while this was not the case for the subgroup of studies assessing serum endocan. Meta-analysis was also performed for comparison of CKD patients without other comorbidities and healthy controls, which resulted in the same conclusion of higher endocan levels in patients with CKD (SMD 0.74, 95% CI 0.52 to 0.95, p-value<0.01). Moreover, endocan was associated with cardiovascular diseases in CKD.

CONCLUSION

Our study demonstrated that endocan is significantly increased in patients with CKD. This can have clinical implications as well as highlight the need for future research investigating the diagnostic and prognostic role of endocan in CKD.

Serum endocan levels in children with rheumatic aortic insufficiency: can it differentiate bicuspid aortic valve disease from rheumatic heart disease?

AIM

In this study, it was aimed to examine the serum endocan levels in patients with rheumatic aortic regurgitation and to investigate whether it has a value in differentiating it from aortic regurgitation due to bicuspid aortic valve.

METHODS

Blood samples were collected from patients with rheumatic aortic regurgitation (Group 1), incidentally diagnosed patients with borderline or definite rheumatic aortic regurgitation (Group 2), children with bicuspid aortic valve accompanied by aortic regurgitation (Group 3) and healthy children (Group 4) of similar age.

RESULTS

There were 12 children in Group 1, 13 in Group 2, 25 in Group 3, and 25 in Group 4. Groups were similar in terms of age (p = 0.291). There was no statistically significant difference between median serum endocan levels of Group 1 and Group 2 (p = 0.624), and Group 3 and Group 4 (p = 0.443). Despite that, the median serum endocan levels of Group 1 and Group 2 were significantly higher than that of both Group 3 and Group 4 (p = 0.000 for all).

CONCLUSIONS

Our results indicate that serum endocan level can be used to differentiate rheumatic aortic regurgitation from non-rheumatic aortic regurgitation. It is thought that the prognostic role of this marker should be confirmed in long-term, prospective studies with larger samples.

Melatonin blunted the angiogenic activity in 3D colon cancer tumoroids by the reduction of endocan

BACKGROUND

Complexity and heterogeneity of the tumor niche are closely associated with the failure of therapeutic protocols. Unfortunately, most data have been obtained from conventional 2D culture systems which are not completely comparable to in vivo microenvironments. Reconstructed 3D cultures composed of multiple cells are valid cell-based tumor models to recapitulate in vivo-like interaction between the cancer cells and stromal cells and the oncostatic properties of therapeutics. Here, we aimed to assess the tumoricidal properties of melatonin on close-to-real colon cancer tumoroids in in vitro conditions.

METHODS

Using the hanging drop method, colon cancer tumoroids composed of three cell lines, including adenocarcinoma HT-29 cells, fibroblasts (HFFF2), and endothelial cells (HUVECs) at a ratio of 2: 1: 1, respectively were developed using 2.5% methylcellulose. Tumoroids were exposed to different concentrations of melatonin, from 0.005 to 0.8 mM and 4 to 10 mM, for 48 h. The survival rate was measured by MTT and LDH leakage assays. Protein levels of endocan and VEGF were assessed using western blotting. Using histological examination (H & E) staining, the integrity of cells within the tumoroid parenchyma was monitored.

RESULTS

Despite the reduction of viability rate in lower doses, the structure of tumoroids remained unchanged. In contrast, treatment of tumoroids with higher doses of melatonin, 4 and 10 mM, led to disaggregation of cells and reduction of tumoroid diameter compared to the non-treated control tumoroids (p < 0.05). By increasing melatonin concentration from 4 to 10 mM, the number of necrotic cells increased. Data showed the significant suppression of endocan in melatonin-treated tumoroids related to the non-treated controls (p < 0.05). According to our data, melatonin in higher doses did not alter protein levels of VEGF (p > 0.05).

CONCLUSIONS

Melatonin can exert its tumoricidal properties on colon cancer tumoroids via the reduction of tumor cell viability and inhibition of the specific pro-angiogenesis factor.

Investigation of Serum Endocan Levels and Age in Critical Inflammatory Conditions

Aging negatively affects the endothelium. Endocan (ESM-1), an endothelium-derived soluble proteoglycan, participates in fundamental biological processes of endothelial cells. We aimed to examine the role of endothelial dysfunction and age in poor outcomes in critical illness. ESM-1 levels were measured in the sera of mechanically ventilated critically ill patients, including COVID-19, non-septic, and septic patients. The 3 patient cohorts were divided based on age (≥65 and <65). Critically ill COVID-19 patients had statistically higher ESM-1 levels compared to critically ill septic and non-septic patients. Only in critically ill septic patients were ESM-1 levels higher in older compared to younger patients. Finally, the age-subgrouped patients were further subdivided based on intensive care unit (ICU) outcome. ESM-1 levels were similar in COVID-19 survivors and non-survivors, irrespective of age. Interestingly, only for the younger critically ill septic patients, non-survivors had higher ESM-1 levels compared to survivors. In the non-septic survivors and non-survivors, ESM-1 levels remained unaltered in the younger patients and tended to be higher in the elderly. Even though endocan has been recognized as an important prognostic biomarker in critically ill patients with sepsis, in our patient cohort, increased age, as well as the extent of endothelial dysfunction, seemed to affect its prognostic ability.

Elevated Circulating Endocan Levels Are Associated with Increased Levels of Endothelial and Inflammation Factors in Postprandial Lipemia

BACKGROUND

Postprandial lipemia (PPL) causes endothelial dysfunction by causing endothelial damage to lipoproteins that remain rich in triglycerides. Endocan is a proteoglycan with increased tissue expression, endothelial activation, and neovascularization. The aim of the study was to examine circulating endocan levels in PPL subjects by considering the degree of PPL response according to a high-fat test meal. The other aim was to determine the association between endocan levels and endothelial and inflammatory factors.

METHOD

Fifty-four hyperlipidemic subjects and 28 normolipidemic subjects consumed the high-fat meal. Endocan, sICAM-1, sVCAM-1, and VEGFA as endothelial factors and IL-6 and LFA-1α as inflammatory factors were evaluated.

RESULTS

Fasting serum endocan, VEGFA, sICAM-1, sVCAM-1 IL-6, and LFA-1α levels were increased in the PPL group compared to the control group. The PPL group was divided into tertiles based on mean AUC levels. Endocan levels in tertile 3 were at the highest and were increased significantly compared to tertiles 1 and 2. AUC and endocan levels were positively correlated with other endothelial and inflammation factors. ROC analysis showed endocan levels to be one of the highest values.

CONCLUSIONS

Circulating endocan is seen at significantly higher levels and independently associated with endothelial and inflammatory factors in postprandial lipemia and dyslipidemia.

Systemic Cytokines in Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a vasoproliferative vitreoretinal disorder, is the leading cause of childhood blindness worldwide. Although angiogenic pathways have been the main focus, cytokine-mediated inflammation is also involved in ROP etiology. Herein, we illustrate the characteristics and actions of all cytokines involved in ROP pathogenesis. The two-phase (vaso-obliteration followed by vasoproliferation) theory outlines the evaluation of cytokines in a time-dependent manner. Levels of cytokines may even differ between the blood and the vitreous. Data from animal models of oxygen-induced retinopathy are also valuable. Although conventional cryotherapy and laser photocoagulation are well established and anti-vascular endothelial growth factor agents are available, less destructive novel therapeutics that can precisely target the signaling pathways are required. Linking the cytokines involved in ROP to other maternal and neonatal diseases and conditions provides insights into the management of ROP. Suppressing disordered retinal angiogenesis via the modulation of hypoxia-inducible factor, supplementation of insulin-like growth factor (IGF)-1/IGF-binding protein 3 complex, erythropoietin, and its derivatives, polyunsaturated fatty acids, and inhibition of secretogranin III have attracted the attention of researchers. Recently, gut microbiota modulation, non-coding RNAs, and gene therapies have shown promise in regulating ROP. These emerging therapeutics can be used to treat preterm infants with ROP.

Evaluation of arterial stiffness and serum endocan levels in patients with primary aldosteronism with new-onset hypertension and long-term hypertension

PURPOSE

There is growing evidence that prolonged exposure to high serum aldosterone concentrations results in target organ damage to the heart, kidney, and arterial wall, and that primary aldosteronism (PA) is associated with increased cardiovascular risk. In this study, we aimed to evaluate cardiovascular disease (CVD) risk indicators such as arterial stiffness [with pulse wave velocity (PWV) measurement] in PA patients and endocan levels, which is a biomarker of endothelial dysfunction.

METHODS

28 patients with PA were included in our study. As the control group, 14 patients with essential hypertension (EHT) and 28 normotensive healthy volunteers were included. Height, weight, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), serum fasting glucose, insulin, hemoglobin A1c (HbA1c), C-reactive protein (CRP), lipids and endocan levels of all subjects in the PA, EHT and control groups were measured. PWV measurements were performed to assess arterial stiffness.

RESULTS

In the PA group, PWV levels were similar to the EHT group, and endocan levels were lower than the EHT group. In the PA group, PWV levels were higher than the control group, and endocan levels were lower than the control group. When we compared the PA group with new-onset HT with the PA group with long-term HT, PWV levels were higher in the PA group with long-term HT. When we compared the long-term HT group with the EHT group, PWV levels were higher in the long-term HT PA group and endocan levels were higher in the EHT group. When we compared the PA group with long-term HT with the control group, PWV levels were higher in the PA group with long-term HT, and endocan levels were similar in both groups.

CONCLUSIONS

In our study, it was determined that arterial stiffness increased in PA cases with long-term HT compared to PA cases with new-onset HT, EHT cases and normotensive healthy cases. We found that endocan levels in PA patients were also lower than both EHT patients and healthy controls.

Fibroblast growth factor-2 bound to specific dermal fibroblast-derived extracellular vesicles is protected from degradation

Fibroblast growth factor-2 (FGF2) has multiple roles in cutaneous wound healing but its natural low stability prevents the development of its use in skin repair therapies. Here we show that FGF2 binds the outer surface of dermal fibroblast (DF)-derived extracellular vesicles (EVs) and this association protects FGF2 from fast degradation. EVs isolated from DF cultured in the presence of FGF2 harbor FGF2 on their surface and FGF2 can bind purified EVs in absence of cells. Remarkably, FGF2 binding to EVs is restricted to a specific subpopulation of EVs, which do not express CD63 and CD81 markers. Treatment of DF with FGF2-EVs activated ERK and STAT signaling pathways and increased cell proliferation and migration. Local injection of FGF2-EVs improved wound healing in mice. We further demonstrated that binding to EVs protects FGF2 from both thermal and proteolytic degradation, thus maintaining FGF2 function. This suggests that EVs protect soluble factors from degradation and increase their stability and half-life. These results reveal a novel aspect of EV function and suggest EVs as a potential tool for delivering FGF2 in skin healing therapies.

Therapeutic Effects of Boric Acid in a Septic Arthritis Model Induced by Escherichia coli in Rats

The study aimed to evaluate the therapeutic effect of boric acid (BA) in experimentally induced septic arthritis. A total of 30 rats, 6 rats in each group (5 groups), were used in the study. No treatment was applied to the rats in the control group. Only BA was administered intraperitoneally (IP) to the rats in the bor group. Escherichia coli was administered at a single dose of 25 μL, 1 × 10¹⁰ cfu/rat from the right foot pad of the rats, via intra-articular route, to the mice in the arthritis, arthritis-bor, and arthritis-antb groups. Then, BA at a dose of 50 mg/kg and cefazolin at a dose of 25 mg/kg were administered to the rats in the arthritis-bor and arthritis-antb groups, respectively, for 7 days via the IP route. At the end of the study, all animals were euthanized following the ethical rules. Blood and tissue samples were taken from the rats for biochemical and histopathological analyses. The levels of GSH, MDA, Endoglin, Endocan, and TNF-β markers were measured in the blood samples taken. A significant decrease was observed in MDA and Endoglin levels in the boric acid-administered group compared with the arthritis group, while a significant increase was observed at the GSH level. Histopathologically, it was determined that the reactive surrounding tissue response in the bor group was significantly reduced. As a result, a significant decrease in inflammation was found biochemically and histopathologically in the groups treated with BA.

Increasing circulating ESM-1 and adhesion molecules are associated with earlystage atherosclerosis in OSA patients:A cross-sectional study

BACKGROUND

There are increasing evidences for a direct relationship between the vascular system and obstructive sleep apnea (OSA). The aim of this study was to investigate the relationship between circulating endothelial cell specific molecule-1 (ESM-1), adhesion molecules and subclinical atherosclerosis in patients with OSA.

METHODS

This was a cross-sectional study in which 161 patients with OSA and 56 controls were recruited. Demographic data, biochemical and polysomnography parameters were collected. We used a powerful high-throughput Multiplex Immunobead Assay technique to simultaneously test plasm levels of ESM-1, P-selectin, E-selectin, L-selectin, inter-cellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1). Carotid intima-media thickness (CIMT) were measured as parameters of vascular endothelial dysfunction and early atherosclerosis.

RESULTS

Increasing circulating levels of ESM-1, P-selectin, E-selectin, L-selectin, ICAM-1 and VCAM-1 were found increased in patients with OSA (all P &lt; 0.001). Furthermore, OSA patients exhibited increased CIMT than controls (P &lt; 0.05). Multivariate linear analysis indicated that elevated ESM-1, P-Selectin, E-selectin, and L-selectin levels were associated with AHI (all P &lt; 0.05). Moreover, multivariate analysis showed that increasing ESM-1, VCAM-1, P-Selectin, and L-selectin were significantly associated with thick CIMT in OSA patients (all P &lt; 0.05).

CONCLUSIONS

Increased circulating ESM-1 and adhesion molecules associated with thick CIMT in OSA, which is a marker of subclinical atherosclerosis. Strict attention to monitor circulating ESM-1 and adhesion molecules is necessary for early detection of subclinical atherosclerosis in OSA patients.

Contemporary Biomarkers in Pulmonary Embolism Diagnosis: Moving beyond D-Dimers

Pulmonary embolism (PE) is a rather common cardiovascular disorder constituting one of the major manifestations of venous thromboembolism (VTE). It is associated with high mortality and substantial recurrence rates, and its diagnosis may be challenging, especially in patients with respiratory comorbidities. Therefore, providing a prompt and accurate diagnosis for PE through developing highly sensitive and specific diagnostic algorithms would be of paramount importance. There is sound evidence supporting the use of biomarkers to enhance the diagnosis and predict the recurrence risk in patients with PE. Therefore, several novel biomarkers, such as factor VIII, Ischemia Modified Albumin, and fibrinogen, as well as several MicroRNAs and microparticles, have been investigated for the diagnosis of this clinical entity. The present review targets to comprehensively present the literature regarding the novel diagnostic biomarkers for PE, as well as to discuss the evidence for their use in daily routine.

Plasma Endocan as a Biomarker of Thrombotic Events in COVID-19 Patients

(1) Background: Endocan is a marker of endothelial dysfunction that may be associated with thrombotic events. The aim of the study was to investigate the performance of endocan as a marker of thrombotic events in COVID-19 patients. (2) Methods: We measured endocan in plasma from 79 documented COVID-19 patients classified according to disease severity (from mild to critical). Thrombotic events were recorded. (3) Results: Endocan concentrations at admission were significantly increased according to COVID-19 severity. Levels of endocan were significantly increased in patients experiencing thrombotic events in comparison with those without (16.2 (5.5−26.7) vs. 1.81 (0.71−10.5) ng/mL, p < 0.001). However, endocan concentrations were not different between pulmonary embolism and other thrombotic events. The Receiver Operating Characteristic (ROC) analysis for the identification of thrombotic events showed an area under the ROC curve (AUC) of 0.776 with an optimal threshold at 2.83 ng/mL (93.8% sensitivity and 54.7% specificity). When combining an endocan measurement with D-dimers, the AUC increased to 0.853. When considering both biomarkers, the Kaplan−Meier survival curves showed that the combination of endocan and D-dimers better discriminated patients with thrombotic events than those without. The combination of D-dimers and endocan was independently associated with thrombotic events. (4) Conclusions: Endocan might be a useful and informative biomarker to better identify thrombotic events in COVID-19 patients.

Serum Endocan Levels and Subclinical Atherosclerosis in Behçet's Syndrome

Background and Aim

Behçet disease (BD) is a rare chronic relapsing-remitting inflammatory systemic vasculitis. BD patients were reported to have marked acceleration of subclinical atherosclerosis (SCA). Endocan is a soluble proteoglycan mainly secreted by the activated endothelium. The present study aimed to assess the relation between serum endocan levels and SCA in BD patients.

Subjects and Methods

The study included 40 adult BD patients in addition to twenty age- and sex-matched healthy controls. BD was diagnosed according to International Study Group criteria. Upon recruitment, all participants were subjected to careful history taking and thorough clinical examination. BD activity was assessed using Behçet Syndrome Activity Score. Measurement of serum endocan was performed using quantitative double-antibody sandwich ELISA kit. CIMT measurement was done using B-mode ultrasound.

Results

Comparison between patients and controls regarding serum endocan levels revealed significantly higher endocan levels in BD patients [median (IQR): 155.0 (69.3–610.0) versus 73.8 (51.9–94.6)]. Using ultrasound assessment, SCA was found in 14 BD patients (35.0%). Comparison between patients with SCA and patients without regarding the clinical and laboratory data revealed that the former group had significantly higher CRP [median (IQR): 36.5 (26.8–43.5) versus 21.0 (11.8–26.8) mg/dL, p < 0.001] and endocan [median (IQR): 622.0 (107.4–974.8) versus 104.5 (64.0–342.0) mg/dL, p = 0.004] levels. Logistic regression analysis recognized endocan [OR (95% CI): 1.0 (1.0–1.012), p0.035] levels as significant predictor of SCA in multivariate analysis.

Conclusion

The present study identified the clinical value of serum endocan levels as a possible early marker of vascular involvement in BD patients.

P2Y2R-Mediated PAK1 Activation Is Involved in ESM-1 Overexpression in RT-R-MDA-MB-231 through FoxO1 Regulation

ESM-1, overexpressed in several cancer types, is a potential cancer diagnostic and prognostic indicator. In our previous study, we determined that RT-R-TNBC cells were more aggressive than TNBC cells, and this difference was associated with ESM-1 overexpression. However, the mechanism explaining upregulated ESM-1 expression in RT-R-TNBC cells compared to TNBC cells was unclear. Therefore, we aimed to identify the mechanism by which ESM-1 is overexpressed in RT-R-MDA-MB-231 cells. RT-R-MDA-MB-231 cells were treated with various ESM-1 transcription factor inhibitors, and only the FoxO1 inhibitor downregulated ESM-1 expression. FoxO1 nuclear localization was modulated by JNK and p38 MAPKs, which were differentially regulated by PKC, PDK1 and PAK1. PAK1 profoundly modulated JNK and p38 MAPKs, whereas PKC and PDK1 affected only p38 MAPK. P2Y2R activated by ATP, which is highly released from RT-R-BC cells, was involved in PAK1 activation, subsequent JNK and p38 MAPK activation, FoxO1 induction, and ESM-1 expression in RT-R-MDA-MB-231 cells. These findings suggest for the first time that ESM-1 was overexpressed in RT-R-MDA-MB-231 cells and regulated through the P2Y2R-PAK1-FoxO1 signaling pathway.

Prognostic and Diagnostic Value of Endocan in Kidney Diseases

Endocan, previously called endothelial cell-specific molecule-1, is a soluble proteoglycan that is predominantly expressed in vascular endothelial cells of the lungs and kidneys. It is upregulated by proinflammatory cytokines and plays a critical role in inflammatory, proliferative, and neovascularization processes. The utility of endocan as a biomarker in a wide spectrum of diseases is being increasingly acknowledged. In this review, we summarize the current evidence concerning the role of endocan in kidney diseases, with emphasis on its prognostic and diagnostic value. It seems that the determination of plasma endocan levels may provide useful prognostic information in many types of renal failure such as chronic kidney disease, IgA nephropathy, and diabetic nephropathy. Endocan could additionally improve the early diagnostic evaluation of acute kidney disease, chronic renal allograft injury, and acute rejection after kidney transplantation, thus contributing to endothelial cell injury monitoring in a timely manner.

Assessment of serum endocan levels in patients with beta-thalassemia minor

OBJECTIVE

Beta-thalassemia minor is a blood disease caused by a hereditary decrease in beta-globin synthesis, frequently leading to hypochromic microcytic anemia. Formerly called endothelial cell-specific molecule 1, endocan is a proteoglycan released by vascular endothelial cells in many organs. Our aim was to investigate the relationship between the beta-thalassemia minor patients and the healthy control group in terms of serum endocan level.

METHODS

The study was performed in a total of 80 subjects. They were divided into two groups, the beta-thalassemia minor group (n=40) and the healthy control group (n=40). Serum endocan levels, age, sex, body mass index value, and tobacco use data of these groups were compared.

RESULTS

No statistically significant difference was detected between the two groups in terms of age, sex, and body mass index values (p>0.05). Endocan levels were measured to be 206.85±88.1 pg/mL in the beta-thalassemia minor group and 236.1±162.8 pg/mL in the control group with no significant difference between the groups in terms of serum endocan levels (p>0.05).

CONCLUSIONS

In our study, there was no change in endocan level in beta-thalassemia minor. This might be because serum endocan levels are affected by multi-factorial reasons. Serum endocan levels may be altered secondarily to decreased beta-globin chain, increased sympathetic activity due to anemia, or platelet dysfunction induced by oxidative stress in beta-thalassemia minor. Further multicenter studies involving more patients are necessary to demonstrate this.

Changes in endocan and dermatan sulfate are associated with biomechanical properties of abdominal aortic wall during aneurysm expansion and rupture

BACKGROUND AND AIMS

The study aimed to assess the potential of proteoglycans (PG) and collagens as serological biomarkers in the abdominal aortic aneurysm (AAA). Furthermore, we investigated the underlying mechano-biological interactions and signaling pathways.

METHODS

Tissue and serum samples from patients with ruptured AAA (rAAA, n=29), elective AAA (eAAA, n=78), and healthy individuals (n=8) were evaluated by histology, immunohistochemistry and Enzyme-linked Immunosorbent Assay (ELISA), mechanical properties were assessed by tensile tests. Regulatory pathways were determined by membrane-based sandwich immunoassay.

RESULTS

In AAA samples, collagen type I and III (Col1, Col3), chondroitin sulfate (CS), and dermatan sulfate (DS) were significantly increased compared to controls (3.0-, 3.2-, 1.3-, and 53-fold; p<0.01). Col1 and endocan were also elevated in the serum of AAA patients (3.6- and 6.0-fold; p<0.01), while DS was significantly decreased (2.5-fold; p<0.01). Histological scoring showed increased total PGs and focal accumulation in rAAA compared to eAAA. Tissue β-stiffness was higher in rAAA compared to eAAA (2.0-fold, p=0.02). Serum Col1 correlated with maximum tensile force and failure tension (r=0.448 and 0.333; p<0.01 and =0.02), tissue endocan correlated with α-stiffness (r=0.340; p<0.01). Signaling pathways in AAA were associated with ECM synthesis and VSMC proliferation. In particular, Src family kinases, PDGF- and EGF-related proteins seem to be involved.

CONCLUSIONS

Our findings reveal a structural association between collagen and PGs and their response to changes in mechanical loads in AAA. Particularly Col1 and endocan reflect the mechano-biological conditions of the aortic wall also in the patient's serum and might serve for AAA risk stratification.

Diagnostic work up: Laboratory and biomarkers

This chapter will focus on the diagnostic work around sexual dysfunction in Parkinson's disease, especially laboratory tests and biomarkers. A number of methods to analyze if sexual dysfunction is caused by neural pathology, vascular dysfunction or other mechanisms are now available. Other methods can be used to differentiate between psychogenic/functional reasons behind sexual dysfunction and organic ones. The role of biomarkers for diagnosis, but also for understanding the reason behind and for counteracting sexual dysfunction is becoming more evident. There is also a rich and increasing number of scales and other instruments available for detecting and quantifying sexual hypo- and hyperactivity. When investigating the reason behind sexual dysfunction in patients with Parkinson's disease comorbidities should also be considered. Finally, early and pronounced sexual dysfunction might in some cases be an indication that differential diagnosis, like Multisystem Atrophy, should be thought about. All these aspects of the diagnostic procedures around sexual dysfunction in Parkinson's disease will be covered in this chapter.

Proteoglycan Endocan: A multifaceted therapeutic target in Cancer

Endocan is known to be a circulating dermatan sulfate proteoglycan that regulates endothelial cell function. Dysregulation of endocan expression is observed not only in the tumor vasculature but also in cancer cells. Accumulating evidence has revealed that disordered endocan facilitates cancer progression via enhancing cancer cell proliferation, cell mobility, and cancer stemness properties. Recently, various interacting proteins and diverse subcellular localizations of endocan were identified in cancer cells. Herein, we summarize the application of endocan in cancer diagnoses and prognoses using serum and tumor specimens. We further discuss that the aberrant molecular characteristics of endocan may be due to the mislocalization of endocan in cancer cells. Defining the specific cellular roles of endocan will provide a promising diagnostic factor and therapeutic target for cancer patients.

The combination of soluble tumor necrosis factor receptor type 1 and fibroblast growth factor 21 exhibits better prediction of renal outcomes in patients with type 2 diabetes mellitus

PURPOSE

Numerous biomarkers of diabetic kidney disease (DKD) are associated with renal prognosis but head-to-head comparisons are lacking. This study aimed to examine the association of soluble tumor necrosis factor receptor type 1 (sTNFR1), fibroblast growth factor 21 (FGF-21), endocan, N-terminal pro-brain natriuretic peptide (NT-pro-BNP), and renal outcomes of patients with or without clinical signs of DKD.

METHODS

A total of 312 patients were enrolled in a prospective observational study that excluded individuals with estimated glomerular filtration rates (eGFR) < 30 mL/min/1.73 m². Composite renal outcomes included either a > 30% decline in eGFR and worsening albuminuria or both from consecutive tests of blood/urine during a 3.5-year follow-up period.

RESULTS

Higher sTNFR1 and FGF-21, rather than endocan and NT-pro-BNP, levels were associated with renal outcomes but the significance was lost after adjusting for confounders. However, sTNFR1 levels ≥ 9.79 pg/dL or FGF-21 levels ≥ 1.40 pg/dL were associated with renal outcomes after adjusting for the confounders (hazard ration [HR] 2.76, 95% confidence interval [CI] 1.36-5.60, p = 0.005 for sTNFR1 level; HR 1.95, 95% CI 1.03-3.69, p = 0.03 for FGF-21 level). The combination of both levels exhibited even better association with renal outcomes than did either one alone (adjusted HR 4.45, 95% CI 1.86-10.65, p = 0.001). The results were consistent among patients with preserved renal function and normoalbuminuria.

CONCLUSION

Both sTNFR1 and FGF-21 levels were associated with renal outcomes of in patients with type 2 diabetes, and the combination of the abovementioned markers exhibits better predictability.

Arterial stiffness, carotid intima-media thickness, endocan and A disintegrin-like and metalloprotease with thrombospondin type I motif 9 levels and their relationship with disease activity in acromegaly patients with and without cardiovascular risk factors

OBJECTIVE

Cardiovascular complications such as cardiomyopathy and endothelial dysfunction, which are frequently seen in patients with acromegaly, are among the most important causes of morbidity and mortality. In this study, we aimed to investigate arterial stiffness, carotid intima-media thickness, endocan and A disintegrin-like and metalloprotease with thrombospondin type I motif 9 (ADAMTS9) levels and their relationship with disease activity in acromegaly patients with and without cardiovascular risk factors.

DESIGN

A total of 60 patients with acromegaly, 25 with active disease, 26 with well-controlled disease, and 9 newly diagnosed, and 60 age-, sex- and body mass index (BMI)-matched healthy control subjects were enrolled in this study. All subjects' height, weight, BMI, systolic blood pressure (SBP), distolic blood pressure (DBP), fasting plasma glucose (FPG), insulin, hemoglobin A1c (HbA1c), C-reactive protein (CRP), lipid, endocan, ADAMTS9, pulse wave velocity (PWV) and carotid intima-media thickness (CIMT) measurements were performed.

RESULTS

SBP, DBP, FPG, HbA1c and PWV levels of the acromegaly group were higher than the control group. In acromegaly patients with cardiovascular disease (CVD) risk factors, PWV was higher than the control group, and in acromegaly patients without CVD risk factor, PWV was similar to the control group. In the correlation analysis, a positive correlation was found between PWV and age, BMI, SBP, DBP, FPG and HbA1c levels in the acromegaly group.

CONCLUSIONS

In our study, we found that arterial stiffness increased in acromegaly patients with CVD risk factors, and that increased arterial stiffness was associated with hemodynamic (SBP, DBP) and metabolic (BMI, FPG, HBA1C) parameters.

Inherited Proteoglycan Biosynthesis Defects-Current Laboratory Tools and Bikunin as a Promising Blood Biomarker

Proteoglycans consist of proteins linked to sulfated glycosaminoglycan chains. They constitute a family of macromolecules mainly involved in the architecture of organs and tissues as major components of extracellular matrices. Some proteoglycans also act as signaling molecules involved in inflammatory response as well as cell proliferation, adhesion, and differentiation. Inborn errors of proteoglycan metabolism are a group of orphan diseases with severe and irreversible skeletal abnormalities associated with multiorgan impairments. Identifying the gene variants that cause these pathologies proves to be difficult because of unspecific clinical symptoms, hardly accessible functional laboratory tests, and a lack of convenient blood biomarkers. In this review, we summarize the molecular pathways of proteoglycan biosynthesis, the associated inherited syndromes, and the related biochemical screening techniques, and we focus especially on a circulating proteoglycan called bikunin and on its potential as a new biomarker of these diseases.

Inhalation of particulate matter containing free radicals leads to decreased vascular responsiveness associated with an altered pulmonary function

Airborne particulate matter (PM) is associated with an increased risk for cardiovascular diseases. Although the goal of thermal remediation is to eliminate organic wastes through combustion, when incomplete combustion occurs, organics chemisorb to transition metals to generate PM-containing environmentally persistent free radicals (EPFRs). Similar EPFR species have been detected in PM found in diesel and gasoline exhaust, woodsmoke, and urban air. Prior in vivo studies demonstrated that EPFRs reduce cardiac function secondary to elevations in pulmonary arterial pressures. In vitro studies showed that EPFRs increase ROS and cytokines in pulmonary epithelial cells. We thus hypothesized that EPFR inhalation would promote lung inflammation and oxidative stress, leading to systemic inflammation, vascular endothelial injury, and a decline in vascular function. Mice were exposed to EPFRs for either 4 h or for 4 h/day for 10 days and lung and vascular function were assessed. After a 4-h exposure, plasma nitric oxide (NO) was reduced while endothelin-1 (ET-1) was increased, however lung function was not altered. After 10 day, plasma NO and ET-1 levels were again altered and lung tidal volume was reduced. These time course studies suggested the vasculature may be an early target of injury. To test this hypothesis, an intermediate time point of 3 days was selected. Though the mice exhibited no marked inflammation in either the lung or the blood, we did note significantly reduced endothelial function concurrent with a reduction in lung tidal volume and an elevation in annexin V protein levels in the lung. Although vascular dysfunction was not dependent upon inflammation, it may be associated with an injury at the air-blood interface. Gene expression analysis suggested roles for oxidative stress and aryl hydrocarbon receptor (Ahr) signaling. Studies probing the relationship between pulmonary oxidative stress and AhR signaling at the air-blood interface with vascular dysfunction seem warranted.NEW & NOTEWORTHY Particulate matter (PM) resulting from the combustion of organic matter is known to contribute to cardiopulmonary disease. Despite hypotheses that cardiovascular dysfunction occurring after PM exposures is secondary to lung or systemic inflammation, these studies investigating exposures to PM-containing environmentally persistent free radicals (EPFRs) demonstrate that cardiovascular dysfunction precedes pulmonary inflammation. The cardiopulmonary health consequences of EPFRs have yet to be thoroughly evaluated, especially in healthy, adult mice. Our data suggest the vasculature as a direct target of PM exposure, and our studies aimed to elucidate the mechanisms contributing to EPFR-induced vascular dysfunction.

Autoimmune Rheumatic Diseases and Vascular Function: The Concept of Autoimmune Atherosclerosis

Autoimmune rheumatic diseases (AIRDs) with unknown etiology are increasing in incidence and prevalence. Up to 5% of the population is affected. AIRDs include rheumatoid arthritis, system lupus erythematosus, systemic sclerosis, and Sjögren's syndrome. In patients with autoimmune diseases, the immune system attacks structures of its own body, leading to widespread tissue and organ damage, which, in turn, is associated with increased morbidity and mortality. One third of the mortality associated with autoimmune diseases is due to cardiovascular diseases. Atherosclerosis is considered the main underlying cause of cardiovascular diseases. Currently, because of finding macrophages and lymphocytes at the atheroma, atherosclerosis is considered a chronic immune-inflammatory disease. In active inflammation, the liberation of inflammatory mediators such as tumor necrotic factor alpha (TNFa), interleukine-6 (IL-6), IL-1 and other factors like T and B cells, play a major role in the atheroma formation. In addition, antioxidized, low-density lipoprotein (LDL) antibodies, antinuclear antibodies (ANA), and rheumatoid factor (RF) are higher in the atherosclerotic patients. Traditional risk factors like gender, age, hypercholesterolemia, smoking, diabetes mellitus, and hypertension, however, do not alone explain the risk of atherosclerosis present in autoimmune diseases. This review examines the role of chronic inflammation in the etiology-and progression-of atherosclerosis in autoimmune rheumatic diseases. In addition, discussed here in detail are the possible effects of autoimmune rheumatic diseases that can affect vascular function. We present here the current findings from studies that assessed vascular function changes using state-of-the-art techniques and innovative endothelial function biomarkers.

The Role and Validity of Diagnostic Biomarkers in Late-Onset Neonatal Sepsis

Sepsis remains a leading cause of mortality in the neonatal population, and currently, there is still no consensus on an accurate biomarker that can aid prompt diagnosis. This review focuses on studies investigating biomarkers for late-onset neonatal sepsis specifically. We discuss the current evidence for traditionally used biomarkers and present recent developments on more novel markers.  Suitable articles were selected from PubMed, Embase, Medline, Cochrane Handbook of Systematic Reviews, and ScienceDirect. Inclusion criteria were studies published from 2010 to 2020. Exclusion criteria were animal model-based studies. Keywords in search strategy were late-onset neonatal sepsis + biomarkers + diagnosis.  Evidence is growing increasingly weak for commonly studied biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT). Levels of markers such as Serum Amyloid A and Neutrophil CD64 increase more rapidly post-onset of infection compared to CRP. Moreover, this review found that the more novel biomarkers discussed such as presepsin and endocan may show superior and more promising potential as diagnostic markers. However, larger studies over multicenters are deemed essential to ascertain the ideal biomarker.

Neural Tissue Homeostasis and Repair Is Regulated via CS and DS Proteoglycan Motifs

Chondroitin sulfate (CS) is the most abundant and widely distributed glycosaminoglycan (GAG) in the human body. As a component of proteoglycans (PGs) it has numerous roles in matrix stabilization and cellular regulation. This chapter highlights the roles of CS and CS-PGs in the central and peripheral nervous systems (CNS/PNS). CS has specific cell regulatory roles that control tissue function and homeostasis. The CNS/PNS contains a diverse range of CS-PGs which direct the development of embryonic neural axonal networks, and the responses of neural cell populations in mature tissues to traumatic injury. Following brain trauma and spinal cord injury, a stabilizing CS-PG-rich scar tissue is laid down at the defect site to protect neural tissues, which are amongst the softest tissues of the human body. Unfortunately, the CS concentrated in gliotic scars also inhibits neural outgrowth and functional recovery. CS has well known inhibitory properties over neural behavior, and animal models of CNS/PNS injury have demonstrated that selective degradation of CS using chondroitinase improves neuronal functional recovery. CS-PGs are present diffusely in the CNS but also form denser regions of extracellular matrix termed perineuronal nets which surround neurons. Hyaluronan is immobilized in hyalectan CS-PG aggregates in these perineural structures, which provide neural protection, synapse, and neural plasticity, and have roles in memory and cognitive learning. Despite the generally inhibitory cues delivered by CS-A and CS-C, some CS-PGs containing highly charged CS disaccharides (CS-D, CS-E) or dermatan sulfate (DS) disaccharides that promote neural outgrowth and functional recovery. CS/DS thus has varied cell regulatory properties and structural ECM supportive roles in the CNS/PNS depending on the glycoform present and its location in tissue niches and specific cellular contexts. Studies on the fruit fly, Drosophila melanogaster and the nematode Caenorhabditis elegans have provided insightful information on neural interconnectivity and the role of the ECM and its PGs in neural development and in tissue morphogenesis in a whole organism environment.

The circulatory small non-coding RNA landscape in community-acquired pneumonia on intensive care unit admission

Community‐acquired pneumonia (CAP) is a major cause of sepsis. Despite several clinical trials targeting components of the inflammatory response, no specific treatment other than antimicrobial therapy has been approved. This argued for a deeper understanding of sepsis immunopathology, in particular factors that can modulate the host response. Small non‐coding RNA, for example, micro (mi)RNA, have been established as important modifiers of cellular phenotypes. Notably, miRNAs are not exclusive to the intracellular milieu but have also been detected extracellular in the circulation with functional consequences. Here, we sought to determine shifts in circulatory small RNA levels of critically ill patients with CAP‐associated sepsis and to determine the influence of clinical severity and causal pathogens on small RNA levels. Blood plasma was collected from 13 critically ill patients with sepsis caused by CAP on intensive care unit admission and from 5 non‐infectious control participants. Plasma small RNA‐sequencing identified significantly altered levels of primarily mature miRNAs in CAP relative to controls. Pathways analysis of high or low abundance miRNA identified various over‐represented cellular biological pathways. Analysis of small RNA levels against common clinical severity and inflammatory parameters indices showed direct and indirect correlations. Additionally, variance of plasma small RNA levels in CAP patients may be explained, at least in part, by differences in causal pathogens. Small nuclear RNA levels were specifically altered in CAP due to Influenza infection in contrast to Streptococcus pneumoniae infection. Pathway analysis of plasma miRNA signatures unique to Influenza or Streptococcus pneumoniae infections showed enrichment for specific proteoglycan, cell cycle, and immunometabolic pathways.

Targeting Endothelial Cell-Specific Molecule 1 Protein in Cancer: A Promising Therapeutic Approach

Despite the dramatic advances in cancer research in the past few years, effective therapeutic strategies are urgently needed. Endothelial cell-specific molecule 1 (ESM-1), a soluble dermatan sulfate proteoglycan, also known as endocan, serves as a diagnostic and prognostic indicator due to its aberrant expression under pathological conditions, including cancer, sepsis, kidney diseases, and cardiovascular disease. Significantly, ESM-1 can promote cancer progression and metastasis through the regulation of tumor cell proliferation, migration, invasion, and drug resistant. In addition, ESM-1 is involved in the tumor microenvironment, containing inflammation, angiogenesis, and lymph angiogenesis. This article reviews the molecular and biological characteristics of ESM-1 in cancer, the underlying mechanisms, the currently clinical and pre-clinical applications, and potential therapeutic strategies. Herein, we propose that ESM-1 is a new therapeutic target for cancer therapy.

The significance of endocan immunohistochemical expression in chronic plaque psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory skin disease with immune-mediated mechanism. Endocan is a soluble dermatan sulfate proteoglycan expressed by endothelium of blood vessels.

AIMS

The present study aims to evaluate immunohistochemical localization of endocan in psoriatic skin in comparison with normal skin and to correlate its expression with the clinical and pathological data of psoriasis.

PATIENTS/METHODS

Skin biopsies from 36 psoriatic patients and 40 normal subjects were taken and processed for immunohistochemical staining of endocan.

RESULTS

Endocan was expressed in 63.9% and in 36.1% of epidermal keratinocytes and dermal endothelial and inflammatory cells of psoriatic skin, respectively, compared with its expression in 30% of epidermis of normal skin. Diffuse epidermal expression of endocan was in favor of cases with more angiogenesis and its intense expression was in favor of marked acanthosis and with cases affecting trunk as main presentation. Positive dermal endocan expression was significantly associated with marked parakeratosis and with more angiogenesis.

CONCLUSION

Endocan is over-expressed in psoriatic skin from epidermal keratinocytes and dermal endothelial and inflammatory cells. Endocan enhances angiogenesis and proliferation of psoriatic skin contributing to pathogenic mechanisms of psoriasis.

Analysis of Inflammatory Mediator Profiles in Sepsis Patients Reveals That Extracellular Histones Are Strongly Elevated in Nonsurvivors

The timely recognition of sepsis and the prediction of its clinical course are challenging due to the complex molecular mechanisms leading to organ failure and to the heterogeneity of sepsis patients. Treatment strategies relying on a “one-fits-all” approach have failed to reduce mortality, suggesting that therapeutic targets differ between patient subgroups and highlighting the need for accurate analysis of the molecular cascades to assess the highly variable host response. Here, we characterized a panel of 44 inflammatory mediators, including cytokines, chemokines, damage-associated molecular patterns, and coagulation-related factors, as well as markers of endothelial activation in 30 patients suffering from renal failure in the course of sepsis. All patients received continuous veno-venous hemodialysis with either high cut-off filters or with standard filters, and mediators were quantified for all patients at the initiation of dialysis and after 24 h and 48 h. Mediator concentrations in individual patients ranged widely, demonstrating the heterogeneity of sepsis patients. None of the mediators correlated with SAPS III or TISS scores. The overall in-hospital mortality of the study population was 56.7% (57.1% vs. 56.3% for high cut-off vs. standard filter). The two filter groups differed regarding most of the mediator levels at baseline, prohibiting conclusions regarding the effect of standard filters versus high cut-off filters on mediator depletion. The elevation and correlation of damage-associated molecular patterns and markers of endothelial activation gave evidence of severe tissue damage. In particular, extracellular histones were strongly increased and were almost 30-fold higher in nonsurvivors as compared to survivors, indicating their diagnostic and prognostic potential.

Direct interaction of β-catenin with nuclear ESM1 supports stemness of metastatic prostate cancer

Wnt/β-catenin signaling is frequently activated in advanced prostate cancer and contributes to therapy resistance and metastasis. However, activating mutations in the Wnt/β-catenin pathway are not common in prostate cancer, suggesting alternative regulations may exist. Here, we report that the expression of endothelial cell-specific molecule 1 (ESM1), a secretory proteoglycan, is positively associated with prostate cancer stemness and progression by promoting Wnt/β-catenin signaling. Elevated ESM1 expression correlates with poor overall survival and metastasis. Accumulation of nuclear ESM1, instead of cytosolic or secretory ESM1, supports prostate cancer stemness by interacting with the ARM domain of β-catenin to stabilize β-catenin-TCF4 complex and facilitate the transactivation of Wnt/β-catenin signaling targets. Accordingly, activated β-catenin in turn mediates the nuclear entry of ESM1. Our results establish the significance of mislocalized ESM1 in driving metastasis in prostate cancer by coordinating the Wnt/β-catenin pathway, with implications for its potential use as a diagnostic or prognostic biomarker and as a candidate therapeutic target in prostate cancer.

The relationship of the serum endocan level with the CHA2DS2-VASc score in patients with paroxysmal atrial fibrillation

Background

In this study considering the relationship between serum endocan and CHA₂DS₂-VASc score, we assumed that endocan level could be a new biomarker for stroke risk in patients with paroxysmal atrial fibrillation (PAF). It was examined that endocan could be an alternative to determine the risk of stroke and anticoagulation strategy in patients with PAF. The CHA₂DS₂-VASc scores were calculated for 192 patients with PAF, and their serum endocan levels were measured. The patients were divided into two groups as those with low to moderate (0-1) and those with high (≥ 2) CHA₂DS₂-VASc scores, and the endocan levels were compared between these two groups.

Results

The serum endocan level was significantly higher in the high CHA₂DS₂-VASc score group (p < 0.001). In the multivariate logistic regression analysis, endocan, C-reactive protein, and low-density lipoprotein were found to be independent determinants of the CHA₂DS₂-VASc score. The predictive value of endocan was analyzed using the ROC curve analysis, which revealed that endocan predicted a high stroke risk (CHA₂DS₂-VASc ≥ 2) at 82.5% sensitivity and 71.2% specificity at the cutoff value of 1.342.

Conclusion

This study indicates that endocan is significantly associated with CHA₂DS₂-VASc score. We demonstrated that endocan could be a new biomarker for the prediction of a high stroke risk among patients diagnosed with PAF.

Plasma Endocan as a Predictor of Cardiovascular Event in Patients with End-Stage Renal Disease on Hemodialysis

Endocan, a potential biomarker of endothelial dysfunction, is associated with increased cardiovascular risk. We investigated the utility of plasma endocan for predicting cardiovascular risk in end-stage renal disease (ESRD) patients undergoing hemodialysis. Of the 452 patients in the K-cohort, 354 with available plasma endocan levels were enrolled. The correlation between plasma endocan levels and the clinical characteristics of a study population were analyzed. We divided patients into two groups, according to plasma endocan levels, and investigated the predictive value of endocan for the occurrence of cardiovascular events. In a multiple linear regression analysis, plasma endocan levels were positively correlated with previous cardiovascular events and negatively correlated with body mass index, albumin, and triglyceride. Patients with higher plasma endocan levels experienced more frequent cardiovascular events than those with lower plasma endocan levels (12.9% in the lower group vs. 22.7% in the higher group, p = 0.016). Cox proportional hazard models showed that higher plasma endocan levels were an independent predictor of cardiovascular events in ESRD patients on hemodialysis ((hazard ration) HR 1.949, 95% (confidence interval) CI 1.144–3.319, p = 0.014). Our results suggest that plasma endocan level might be a useful biomarker for predicting cardiovascular events in ESRD patients on hemodialysis.

Endocan as a potential biomarker of disease severity and exacerbations in COPD

INTRODUCTION

Endocan is a proteoglycan that is regarded as a novel marker of endothelial dysfunction. Endothelial dysfunction in pulmonary vascular bed is known to play an important role for the pathogenesis of COPD.

OBJECTIVE

This study aimed to determine serum endocan levels in patients with stable COPD and acute exacerbation of COPD (AECOPD) and to test the relationship between serum endocan levels and exacerbations.

METHODS

This study enrolled a total of 55 COPD patients, 24 of which had AECOPD and 31 had stable COPD. All patients' basic demographic and clinical data were recorded and blood samples were collected.

RESULTS

Serum endocan levels were significantly higher in the AECOPD group compared to the stable COPD and control groups (for both p < 0.001) and stable COPD group had higher levels than the control group (p < 0.005). Additionally, serum endocan levels were negatively correlated with FVC, FEV1, partial oxygen pressure and oxygen saturation (r = -0.30, p = 0.03; r = -0.34, p = 0.01; r = -0.34, p = 0.01 and r = -0.36, p = 0.007 respectively), and positively correlated with disease duration and systolic pulmonary artery pressure (r = 0.47, p < 0.001; r = 0.31, p = 0.02 respectively). A cut-off value of 434.29 pg/ml for endocan predicted exacerbation with a sensitivity of 79% and a specificity of 84% (AUC: 0.778, 95% Cl 0.648-0.909; p < 0.001). Logistic regression analysis revealed that increased endocan levels was independent predictor of COPD exacerbation (OR = 9.32, 95%CI, 1.64-52.95; p = 0.01).

CONCLUSION

Endocan may be a novel biomarker for detection of endothelial dysfunction and prediction of exacerbations in patients with COPD.

Systemic Endothelial Activation Is Associated With Early Acute Respiratory Distress Syndrome in Children With Extrapulmonary Sepsis

OBJECTIVES

Systemic endothelial activation may contribute to sepsis-associated organ injury, including acute respiratory distress syndrome. We hypothesized that children with extrapulmonary sepsis with versus without acute respiratory distress syndrome would have plasma biomarkers indicative of increased endothelial activation and that persistent biomarker changes would be associated with poor outcome.

DESIGN

Observational cohort.

SETTING

Academic PICU.

PATIENTS

Patients less than 18 years old with sepsis from extrapulmonary infection with (n = 46) or without (n = 54) acute respiratory distress syndrome and noninfected controls (n = 19).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Endothelial (angiopoietin-1, angiopoietin-2, tyrosine kinase with immunoglobulin-like loop epidermal growth factor homology domain 2, vascular endothelial growth factor, soluble fms-like tyrosine kinase, von Willebrand factor, E-selectin, intercellular adhesion molecule, vascular cell adhesion molecule, thrombomodulin) and inflammatory biomarkers (C-reactive protein, interleukin-6, and interleukin-8) were measured from peripheral plasma collected within 3 days (time 1) of sepsis recognition and at 3-6 days (time 2) and 7-14 days (time 3). Time 1 biomarkers and longitudinal measurements were compared for sepsis patients with versus without acute respiratory distress syndrome and in relation to complicated course, defined as greater than or equal to two organ dysfunctions at day 7 or death by day 28. Angiopoietin-2, angiopoietin-2/angiopoietin-1 ratio, tyrosine kinase with immunoglobulin-like loop epidermal growth factor homology domain 2, vascular endothelial growth factor, von Willebrand factor, E-selectin, intercellular adhesion molecule, vascular cell adhesion molecule, thrombomodulin, endocan, C-reactive protein, interleukin-6, and interleukin-8 were different between sepsis and noninfected control patients at time 1. Among patients with sepsis, those with acute respiratory distress syndrome had higher angiopoietin-2/angiopoietin-1 ratio, vascular endothelial growth factor, vascular cell adhesion molecule, thrombomodulin, endocan, interleukin-6, and interleukin-8 than those without acute respiratory distress syndrome (all p < 0.003). Angiopoietin-2 and angiopoietin-2/angiopoietin-1 ratio remained higher in sepsis with versus without acute respiratory distress syndrome after multivariable analyses. Time 1 measures of angiopoietin-2, angiopoietin-2/-1 ratio, von Willebrand factor, and endocan were indicative of complicated course in all sepsis patients (all area under the receiver operating curve ≥ 0.80). In sepsis without acute respiratory distress syndrome, soluble fms-like tyrosine kinase decreased more quickly and von Willebrand factor and thrombomodulin decreased more slowly in those with complicated course.

CONCLUSIONS

Children with extrapulmonary sepsis with acute respiratory distress syndrome had plasma biomarkers indicative of greater systemic endothelial activation than those without acute respiratory distress syndrome. Several endothelial biomarkers measured near sepsis recognition were associated with complicated course, whereas longitudinal biomarker changes yielded prognostic information only in those without sepsis-associated acute respiratory distress syndrome.

Endothelial dysfunction in neuroprogressive disorders-causes and suggested treatments

BACKGROUND

Potential routes whereby systemic inflammation, oxidative stress and mitochondrial dysfunction may drive the development of endothelial dysfunction and atherosclerosis, even in an environment of low cholesterol, are examined.

MAIN TEXT

Key molecular players involved in the regulation of endothelial cell function are described, including PECAM-1, VE-cadherin, VEGFRs, SFK, Rho GEF TRIO, RAC-1, ITAM, SHP-2, MAPK/ERK, STAT-3, NF-κB, PI3K/AKT, eNOS, nitric oxide, miRNAs, KLF-4 and KLF-2. The key roles of platelet activation, xanthene oxidase and myeloperoxidase in the genesis of endothelial cell dysfunction and activation are detailed. The following roles of circulating reactive oxygen species (ROS), reactive nitrogen species and pro-inflammatory cytokines in the development of endothelial cell dysfunction are then described: paracrine signalling by circulating hydrogen peroxide, inhibition of eNOS and increased levels of mitochondrial ROS, including compromised mitochondrial dynamics, loss of calcium ion homeostasis and inactivation of SIRT-1-mediated signalling pathways. Next, loss of cellular redox homeostasis is considered, including further aspects of the roles of hydrogen peroxide signalling, the pathological consequences of elevated NF-κB, compromised S-nitrosylation and the development of hypernitrosylation and increased transcription of atherogenic miRNAs. These molecular aspects are then applied to neuroprogressive disorders by considering the following potential generators of endothelial dysfunction and activation in major depressive disorder, bipolar disorder and schizophrenia: NF-κB; platelet activation; atherogenic miRs; myeloperoxidase; xanthene oxidase and uric acid; and inflammation, oxidative stress, nitrosative stress and mitochondrial dysfunction.

CONCLUSIONS

Finally, on the basis of the above molecular mechanisms, details are given of potential treatment options for mitigating endothelial cell dysfunction and activation in neuroprogressive disorders.