Endocan: a novel biomarker associated with well-developed coronary collateral circulation in patients with stable angina and chronic total occlusion

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.

The association of catestatin and endocan with the effects of cardiac shock wave therapy: Biomarker sub-study of the randomized, sham procedure-controlled trial

Introduction

Cardiac shock-wave therapy (CSWT) is a non-invasive regenerative treatment method based on low-frequency ultrasound waves, which stimulate angiogenesis. Current data about the effects of revascularization procedures on angiogenesis biomarkers is limited. Recently, an association of catestatin and endocan with coronary collateral development was shown in several trials. In this study, we aimed to evaluate the impact of CSWT on the dynamics of catestatin and endocan levels and to assess their correlation with parameters of myocardial perfusion and function.

Methods

Prospective, randomized, triple-blind, sham procedure-controlled study enrolled 72 adult subjects who complied with defined inclusion criteria (NCT02339454). We measured biomarkers in 48 patients with stable angina (24 patients of CSWT group, 24 patients of sham-procedure group). Additionally, patients were divided into responders and non-responders according to improvement in myocardial perfusion and/or contractility assessed by myocardial scintigraphy and dobutamine echocardiography (30 and 13 patients, respectively). The blood samples were collected at baseline, after the last treatment procedure (9th treatment week) and at 6-month follow-up to evaluate biomarkers concentration and stored at -80° until analysis. Serum catestatin and endocan levels were determined by commercially available ELISA kits.

Results

Serum catestatin concentration significantly increased in all patients. While endocan levels significantly decreased in the responders sub-group. The increase in catestatin levels at 9th week and 6 months was positively associated with improvement in summed difference score (rho = 0.356, p = 0.028) and wall motion score, WMS (rho = 0.397, p = 0.009) at 6 months in the whole study population. Meanwhile, the decrease in endocan levels over 6 months was positively correlated with improvement in WMS at 3- and 6- months (r = 0.378, p = 0.015 and r = 0.311, p = 0.045, respectively). ROC analysis revealed that a change at 6 months in catestatin and endocan levels significantly predicted improvement in myocardial perfusion and contractile function with 68.9% sensitivity and 75.0% specificity (p = 0.039) and 51.7% sensitivity, and 91.7% specificity (p = 0.017), respectively. Baseline endocan concentration and its change at 6 months predicted response to CSWT with 68.8% sensitivity and 83.3% specificity (p = 0.039) and 81.3% sensitivity and 100% specificity (p < 0.0001), respectively.

Conclusion

This study demonstrates the association of increase in catestatin and decrease in endocan levels with the improvement of myocardial perfusion and contractile function. The potential predictive value of catestatin and endocan dynamics for the response to regenerative therapy is shown.

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.

Peripheral microvascular dysfunction is also present in patients with ischemia and no obstructive coronary artery disease (INOCA)

BACKGROUND

In patients with ischemia and no obstructive coronary artery disease (INOCA), coronary microvascular dysfunction is associated with higher rate of major adverse cardiovascular events.

OBJECTIVE

To demonstrate if microvascular dysfunction present in coronary microcirculation of patients with INOCA may be detected noninvasively in their peripheral circulation.

METHODS

25 patients with INOCA and 25 apparently healthy individuals (controls) were subjected to nailfold videocapillaroscopy (NVC) and venous occlusion plethysmography (VOP) to evaluate peripheral microvascular function and blood collection for biomarkers analysis, including soluble vascular cell adhesion molecule-1 (sVCAM-1), endothelin-1 (ET-1) and C-reactive protein (CRP).

RESULTS

Red blood cell velocity (RBCV) before and after ischemia (RBCVmax) were significantly lower in patients with INOCA (p = 0.0001). Time to reach maximal red blood cell velocity (TRBCVmax) was significantly longer in INOCA group (p = 0.0004). Concerning VOP, maximal blood flow (p = 0.004) and its relative increment were significantly lower in patients with INOCA (p = 0.0004). RBCVmax showed significant correlations with sVCAM-1 (r = -0.38, p <  0.05), ET-1 (r = -0.73, p <  0.05) and CRP (r = -0.33, p <  0.05). Relative increment of maximal post-ischemic blood flow was significantly correlated with sVCAM-1 (r = -0.42, p <  0.05) and ET-1 (r = -0.48, p <  0.05).

CONCLUSIONS

The impairment of microvascular function present in coronary microcirculation of patients with INOCA can be also detected in peripheral microcirculation.

The value of fragmented QRS in predicting the prognosis of chronic total occlusion patients with myocardial infarction history undergoing percutaneous coronary intervention: A 24-months follow-up study

BACKGROUND

Fragmented QRS (fQRS) is a marker of local myocardial scar. This study aimed to analyze the relationship between fQRS and coronary collateral circulation (CCC) and evaluate the predictive value of fQRS for long-term clinical outcomes among patients with chronic total occlusion (CTO) and prior myocardial infarction (MI) who underwent percutaneous coronary intervention (PCI).

METHODS

A total of 862 patients with a definite history of MI who had one CTO coronary artery and underwent PCI between 2013 and 2018 were continuously analyzed. Patients were divided into group A (no Q wave and fQRS, n = 206), group B (fQRS, n = 265), group C (Q wave, n = 391). All patients were followed up for 2 years.

RESULTS

The incidence rate of major adverse cardiovascular events (MACE) in group B was significantly lower than in group C (group B vs. C: 7.2% vs. 11.3%, P = 0.043). The percentage of good CCC was 94.2%, 88.3%, and 82.9% in group A, B, and C (p < .001), respectively. The improvement of cardiac function in group B and A were more significant than in group C. Multivariate Cox regression analysis showed fQRS was an independent protective factor of MACE after PCI within 2 years in CTO patients with prior MI (RR = 0.668, 95% CI [0.422-0.917], p = .001).

CONCLUSION

fQRS is an independent protective factor of prognosis in patients with prior MI and one CTO vessel who underwent PCI, presenting with a higher rate of good CCC, less occurrence of MACE, and better heart function than in Q wave patients.

Improving Collateral Circulation: A Potential Adjunctive Strategy to Prevent or Slow the Progression of Vascular Dementia

Vascular dementia (VaD), a cognitive disorder caused by cerebrovascular pathologies, is the most common cause of dementia in the elderly, being second only to Alzheimer's disease. Researches have shown that adequate cerebral blood flow (CBF) is the first condition for maintaining the structural integrity and normal function of the brain, and VaD is generally considered to be resulted from neuronal loss due to reduced CBF. Collateral circulation, a compensation mechanism for CBF, provides an alternative vascular pathway for blood to reach ischemic tissues, which has been confirmed to be associated with better clinical outcomes of ischemic diseases. At present, considerable effort has been devoted to enhancing the functional prognosis of acute ischemic stroke by improving collateral circulation. Since ischemic stroke is the primary contributor to VaD, it is necessary to explore whether improving collateral circulation is beneficial to prevent or slow the progression of VaD. This article reviews the compensatory characteristics of different levels of cerebral collateral circulation, addresses the relationship between collateral circulation and VaD, and highlights that improving collateral circulation may be a potential adjunctive strategy in preventing and slowing the progression of VaD.

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.

Prediction and identification of novel HLA-A*0201-restricted cytotoxic T lymphocyte epitopes from endocan

Background

Prediction and identification of cytotoxic T lymphocyte (CTL) epitopes from tumor associated antigens is a crucial step for the development of tumor immunotherapy strategy. Endocan has been identified as antigen overexpressed in various tumors.

Methods

In this experiment, we predicted and identified HLA-A2-restricted CTL epitopes from endocan by using the following procedures. Firstly, we predicted the epitopes from the amino acid sequence of endocan by computer-based methods; Secondly, we determined the affinity of the predicted peptide with HLA-A2.1 molecule by peptide-binding assay; Thirdly, we elicited the primary T cell response against the predicted peptides in vitro; Lastly, we tested the specific CTLs toward endocan and HLA-A2.1 positive target cells.

Results

These data demonstrated that peptides of endocan containing residues 4–12 and 9–17 could elicit specific CTLs producing interferon-γ and cytotoxicity.

Conclusions

Therefore, our findings suggested that the predicted peptides were novel HLA-A2.1-restricted CTL epitopes, and might provide promising target for tumor immunotherapy.

Kinetics of endocan in patients undergoing cardiac surgery with and without cardiopulmonary bypass

BACKGROUND

Endocan plays an important role in the processes of inflammation and infection. The use of cardiopulmonary bypass (CPB) during cardiac surgery can induce an inflammatory response. We aimed to describe the kinetics of endocan in patients undergoing cardiac surgery with and without the use of CPB.

METHODS

Single-centre, observational study with retrospective analysis of prospectively collected data, to compare the kinetics of endocan in patients undergoing isolated coronary artery bypass graft (CABG) surgery. Endocan was measured at induction of general anesthesia (baseline), and at 6, 24, 48 and 72 h after the end of surgery. Patients were classified into two groups, namely those undergoing CPB (CPB group) and those without CPB (off-pump group).

RESULTS

In total, 91 patients were included in this analysis: 61 patients in the CPB group and 30 in the off-pump group. There were no major significant differences between groups. Patients with CPB had a significantly higher level of endocan at 6 h (9.7 ± 6.7 ng/ml vs 6.9 ± 3.3 ng/ml, p = 0.03), but the difference was no longer statistically significant at subsequent timepoints. Endocan values were not significantly correlated with the duration of CPB (p = 0.53).

CONCLUSION

Endocan levels in patients undergoing isolated CABG surgery with CPB are significantly higher at 6 h than in patients with off-pump surgery, and peaks earlier in those with CPB (6 h) than in those undergoing off-pump surgery (24 h).