sVE-cadherin and sCD146 serum levels in patients with multiple myeloma

Endothelial barrier dysfunction in systemic inflammation is mediated by soluble VE-cadherin interfering VE-PTP signaling

Breakdown of endothelial barrier integrity determines organ dysfunction and outcome of patients with sepsis. Increased levels of soluble vascular endothelial (VE)-cadherin fragments (sVE-cadherin) have previously been linked with inflammation-induced loss of endothelial barrier function. We provide evidence for a causative role of sVE-cadherin to induce loss of endothelial barrier function. In patients with sepsis, sVE-cadherin levels were associated with organ dysfunction and the need for volume resuscitation. Similarly, LPS-induced systemic inflammation in rats with microvascular dysfunction was paralleled by augmented sVE-cadherin levels. Newly generated recombinant human sVE-cadherin (extracellular domains EC1-5) induced loss of endothelial barrier function in both human microvascular endothelial cells in vitro and in rat mesenteric microvessels in vivo and reduced microcirculatory flow. sVE-cadherinEC1-5 disturbed VE-cadherin-mediated adhesion and perturbed VE-protein tyrosine phosphatase (VE-PTP)/VE-cadherin interaction resulting in RhoGEF1-mediated RhoA activation. VE-PTP inhibitor AKB9778 and Rho-kinase inhibitor Y27632 blunted all sVE-cadherinEC1-5-induced effects, which uncovers a pathophysiological role of sVE-cadherin via dysbalanced VE-PTP/RhoA signaling.

How Does Endothelial Permeability Affect the Development of Juvenile Idiopathic Arthritis? Vascular Endothelial Cadherin as a Promising New Tool Helpful in the Diagnostic Process

Introduction

Vascular endothelial cadherin (VE-cadherin) is a calcium-dependent protein essential for stabilization of the adherens junctions of the endothelial cells. Through vasculogenic mimicry, VE-cadherin may influence angiogenesis in synovial fibroblast-like cells. The soluble extracellular domain of VE-cadherin may be considered an indicator of endothelial dysfunction. Its potential as a diagnostic biomarker in rheumatic diseases, including juvenile idiopathic arthritis (JIA), needs to be investigated.

Materials and Methods

The study group included 80 patients diagnosed with JIA. In 53 individuals, blood samples were obtained twice with an average interval of 102.4 ± 4.6 days. Results from the study group were compared to 29 age- and sex-matched healthy children.

Results

Serum levels of VE-cadherin were significantly higher in JIA patients than in healthy controls. In such comparison, VE-cadherin had 87.5% sensitivity and 69.0% specificity for the cutoff level 4.36 ng/ml (Youden index 0.56, area under the curve 0.724). VE-cadherin concentrations negatively correlated with the disease activity score. However, such finding may be a false result because of the downregulation of VE-cadherin induced by glucocorticosteroids.

Conclusions

VE-cadherin may become a promising diagnostic biomarker of early stages of JIA. Its predictive significance may be decreased by utilization of glucocorticosteroids. A multicentre study including patients with other arthritides is recommended for further evaluation of this protein.

Soluble vascular endothelial-cadherin in CSF after subarachnoid hemorrhage

OBJECTIVE

To determine if CSF and plasma levels of soluble vascular endothelial (sVE)-cadherin are associated with functional outcome after subarachnoid hemorrhage (SAH) and to investigate sVE-cadherin effects on microglia.

METHODS

Serial CSF and plasma were collected from prospectively enrolled patients with nontraumatic SAH from a ruptured aneurysm in the anterior circulation and who required an external ventricular drain for clinical indications. Patients with normal-pressure hydrocephalus without SAH served as controls. For prospective assessment of long-term outcomes at 3 and 6 months after SAH, modified Rankin Scale scores (mRS) were obtained and dichotomized into good (mRS ≤ 2) vs poor (mRS > 2) outcome groups. For SAH severity, Hunt and Hess grade was assessed. Association of CSF sVE-cadherin levels with long-term outcomes, HH grade, and CSF tumor necrosis factor (TNF)-α levels were evaluated. sVE-cadherin effects on microglia were also studied.

RESULTS

sVE-cadherin levels in CSF, but not in plasma, were higher in patients with SAH and were associated with higher clinical severity and higher CSF TNF-α levels. Patients with SAH with higher CSF sVE-cadherin levels over time were more likely to develop worse functional outcome at 3 months after SAH. Incubation of cultured microglia with sVE-cadherin resulted in increased inducible nitric oxide synthase, interleukin-1β, reactive oxygen species, cell soma size, and metabolic activity, consistent with microglia activation. Microinjection of sVE-cadherin fragments into mouse brain results in an increased number of microglia surrounding the injection site, compared to injection of denatured vascular endothelial-cadherin fragments.

CONCLUSIONS

These results support the existence of a novel pathway by which sVE-cadherin, released from injured endothelium after SAH, can shift microglia into a more proinflammatory phenotype and contribute to neuroinflammation and poor outcome in SAH.

Soluble Vascular Endothelial Cadherin as a New Biomarker of Irradiation in Highly Irradiated Baboons with Bone Marrow Protection

Vascular endothelial cadherin is the main component of adherens junctions enabling cohesion of the endothelial monolayer in vessels. The extracellular part of vascular endothelial cadherin (VE-cadherin) can be cleaved, releasing soluble fragments in blood (sVE-cadherin). In some diseases with endothelial dysfunction, a correlation between increased blood sVE-cadherin levels and disease state has been proposed. Irradiation is known to induce endothelial damage, but new serum biomarkers are needed to evaluate endothelial damage after irradiation. Here, the authors investigated whether sVE-cadherin may be an interesting biomarker of irradiation in highly irradiated baboons with bone marrow protection. sVE-cadherin was detected in the plasma of young as well as old baboons. Plasma sVE-cadherin levels significantly decrease a few days after irradiation but recover in the late time after irradiation. Kinetic analysis of plasma sVE-cadherin levels suggests a correlation with white blood cell counts in both the acute phase of irradiation and during hematopoietic recovery, suggesting that plasma sVE-cadherin levels may be partly linked to the disappearance and recovery of white blood cells. Interestingly, after hematopoietic recovery was completed, sVE-cadherin levels were found to exceed control values, suggesting that plasma sVE-cadherin may represent a new biomarker of endothelial damage or neovascularization in the late time after irradiation.

Soluble vascular endothelial-cadherin and auto-antibodies to human vascular endothelial-cadherin in human diseases: Two new biomarkers of endothelial dysfunction

Vascular endothelial-cadherin is the most important transmembrane component of endothelial adherens junctions, exclusively expressed by endothelial cells in all types of vessels. Targeting either the extracellular domain or the cytoplasmic tail deleteriously affects the junctional strength and leads to vascular permeability. Recently, cytokine-induced phosphorylation of the vascular endothelial-cadherin cytoplasmic domain was reported to trigger cleavage of its extracellular domain, producing the soluble form of the protein – soluble vascular endothelial-cadherin. Hence, the presence of soluble vascular endothelial-cadherin or auto-antibodies to human vascular endothelial-cadherin in human serum could signalize the presence of vascular abnormalities. This systematic review covers many human studies reporting increased levels of soluble vascular endothelial-cadherin, as well as auto-antibodies to human vascular endothelial-cadherin, which could be promising biomarkers of endothelial dysfunction in a large panel of diseases.

Soluble vascular endothelial-cadherin levels in patients with sepsis treated with direct hemoperfusion with a polymyxin B-immobilized fiber column

Capillary permeability is a tightly regulated feature of microcirculation in all organ beds; however, in sepsis this feature is fundamentally altered. Several molecules are investigated as associated factors with capillary permeability and vascular endothelial (VE)-cadherin internalization by vascular endothelial growth factor (VEGF)-induced signaling through VEGF receptors leads to increased vascular endothelial cell detachment and trans-endothelial permeability. We investigated serum soluble VE-cadherin levels in septic patients. An enzyme-linked immunoassay was used to measure serum soluble VE-cadherin levels in 47 septic patients treated by direct hemoperfusion with a polymyxin B-immobilized fiber column (DHP-PMX). The serum soluble VE-cadherin level of septic patients before PMX-DHP was 3424.1 ± 2033.0 ng/mL, which was significantly lower than that of the controls (5862.0 ± 1521.2 ng/mL; P < 0.0001). The time course of serum soluble VE-cadherin levels remained unchanged during PMX-DHP therapy. There was no significant difference in serum soluble VE-cadherin levels before PMX-DHP therapy between survivors and non-survivors, and there was no significant difference in those levels between the groups at any time after the initiation of PMX-DHP therapy. There was no correlation between soluble VE-cadherin levels and clinical data, except white blood cell count (r = -0.277, P = 0.0009). There was no correlation between soluble VE-cadherin levels and the levels of angiopoietin 1 and 2. In summary, the relationship between VE-cadherin and capillary permeability in sepsis could not be demonstrated. Soluble VE-cadherins are not reflected in the balance between intercellular junction plasticity and integrity, but VE-cadherin stabilization by its phosphorylation or internalization may be associated with capillary permeability.

High-mobility group box-1 and endothelial cell angiogenic markers in the vitreous from patients with proliferative diabetic retinopathy

The aim of this study was to measure the levels of high-mobility group box-1 (HMGB1) in the vitreous fluid from patients with proliferative diabetic retinopathy (PDR) and to correlate its levels with clinical disease activity and the levels of vascular endothelial growth factor (VEGF), the angiogenic cytokine granulocyte-colony-stimulating factor (G-CSF), the endothelial cell angiogenic markers soluble vascular endothelial-cadherin (sVE-cadherin), and soluble endoglin (sEng). Vitreous samples from 36 PDR and 21 nondiabetic patients were studied by enzyme-linked immunosorbent assay. HMGB1, VEGF, sVE-cadherin, and sEng levels were significantly higher in PDR patients than in nondiabetics (P = 0.008; <0.001; <0.001; 0.003, resp.). G-CSF was detected in only 3 PDR samples. In the whole study group, there was significant positive correlation between the levels of HMGB1, and sVE-cadherin (r = 0.378, P = 0.007). In PDR patients, there was significant negative correlation between the levels of sVE-cadherin and sEng (r = −0.517, P = 0.0005). Exploratory regression analysis identified significant associations between active PDR and high levels of VEGF (odds ratio = 76.4; 95% confidence interval = 6.32–923) and high levels of sEng (odds ratio = 6.01; 95% confidence interval = 1.25–29.0). Our findings suggest that HMGB1, VEGF, sVE-cadherin and sEng regulate the angiogenesis in PDR.

A targeted glycoproteomic approach identifies cadherin-5 as a novel biomarker of metastatic breast cancer

Aberrant glycosylation has long been recognised as a hallmark of cancer, and is increasingly being exploited in biomarker discovery studies. Helix pomatia agglutinin (HPA) is known to bind aberrant glycans associated with metastatic breast cancer, and was used here to isolate glycoproteins from pooled breast cancer serum samples of (i) patients with recurrent breast cancer and (ii) patients with no sign of recurrence 5years after diagnosis of their primary tumour. Pregnancy zone protein, the polymeric immunoglobulin receptor and cadherin-5 emerged as potential markers of metastasis following proteomic identification of HPA binding glycoproteins. ELISAs were developed to verify these findings, and to assess protein glycosylation, in individual patient sera. The cadherin-5 ELISA discriminated serum samples of patients with recurrent breast cancer from those with no sign of recurrence, and analysis of cadherin-5 glycosylation by HPA also showed a significant difference between the two sample groups. The targeted glycoproteomic and validatory approach developed here has shown that when taking into account both the protein levels and HPA binding, serum cadherin-5 discriminated patients with recurrent breast cancer from those with no sign of recurrence with 90% specificity.

Constitutive expression of IL-12R beta 2 on human multiple myeloma cells delineates a novel therapeutic target

The interleukin-12 (IL-12) receptor (R) B2 gene acts as tumor suppressor in human acute and chronic B-cell leukemias/lymphomas and IL-12rb2-deficient mice develop spontaneously localized plasmacytomas. With this background, we investigated the role of IL-12R beta 2 in multiple myeloma (MM) pathogenesis. Here we show the following: (1) IL-12R beta 2 was expressed in primary MM cells but down-regulated compared with normal polyclonal plasmablastic cells and plasma cells (PCs). IL-6 dampened IL-12R beta 2 expression on polyclonal plasmablastic cells and MM cells. (2) IL-12 reduced the proangiogenic activity of primary MM cells in vitro and decreased significantly (P = .001) the tumorigenicity of the NCI-H929 cell line in SCID/NOD mice by inhibiting cell proliferation and angiogenesis. The latter phenomenon was found to depend on abolished expression of a wide panel of proangiogenic genes and up-regulated expression of the antiangiogenic genes IFN-gamma, IFN-alpha, platelet factor-4, and TIMP-2. Inhibition of the angiogenic potential of primary MM cells was related to down-regulated expression of the proangiogenic genes CCL11, vascular endothelial-cadherin, CD13, and AKT and to up-regulation of an IFN-gamma-related antiangiogenic pathway. Thus, IL-12R beta 2 directly restrains MM cell growth, and targeting of IL-12 to tumor cells holds promise as new therapeutic strategy.