Increased soluble platelet/endothelial cell adhesion molecule-1 in the early stages of acute coronary syndromes

Investigation of cardiovascular risk parameters in adolescents with metabolic syndrome

BACKGROUND

Metabolic syndrome leading to type 2 diabetes mellitus and cardiovascular diseases is a chronic multifactorial syndrome, associated with low-grade inflammation status. In our study, we aimed at assessing the serum levels of follistatin (FST), pregnancy-associated plasma protein-A (PAPP-A), and platelet/endothelial cell adhesion molecule-1 (PECAM-1) in adolescent patients with metabolic syndrome.

METHODS

This study was performed in 43 (19 males, 24 females) metabolic syndrome adolescents and 37 lean controls matched for age and sex. The serum levels of FST, PECAM-1, and PAPP-A were measured by using ELISA method.

RESULTS

Serum FST and PAPP-A levels in metabolic syndrome were significantly higher than those of controls (p < 0.005 and p < 0.05). However, there was no difference in serum PECAM-1 levels between metabolic syndrome and control groups (p = 0.927). There was a significant positive correlation between serum FST and triglyceride (r = 0.252; p < 0.05), and PAPP-A and weight, (r = 0.252; p < 0.05) in metabolic syndrome groups. Follistatin was determined statistically significant in both univariate (p = 0,008) and multivariate (p = 0,011) logistic regression analysis.

CONCLUSIONS

Our findings indicated a significant relationship between FST and PAPP-A levels and metabolic syndrome. These findings offer the possibility of using these markers in diagnosis of metabolic syndrome in adolescents as the prevention of the future complications.

Ustekinumab reduces serum protein levels associated with cardiovascular risk in psoriasis vulgaris

Psoriasis increases the risk of cardiovascular disease (CVD). Biomarkers for cardiovascular (CV) risk stratification in psoriasis are lacking, and the effects of psoriasis biologics on CV risk reduction remain unclear. The goal of this study was to identify biomarkers of CV risk in psoriasis blood that are reduced by ustekinumab. We quantified 276 inflammatory and CV-related serum proteins with Olink's multiplex assay in 10 psoriasis patients (vs. 18 healthy controls) and after 12 weeks of ustekinumab treatment. For each protein down-regulated after treatment, the literature was reviewed for studies assessing the protein's association with CVD. Data were collected from each study to calculate CV risk thresholds for each protein, which were compared with protein levels in psoriasis patients before and after treatment. Our results showed that 43 out of 276 proteins were down-regulated after treatment, 25 of which were initially up-regulated at baseline (vs. controls, all p-values ≤0.1). 8 down-regulated proteins were initially elevated above thresholds associated with enhanced CV risk in the literature (myeloperoxidase, C-X-C motif chemokine 10, E-selectin, interleukin-6, cystatin B, von Willebrand factor, tumor necrosis factor receptor 1 and N-terminal prohormone brain natriuretic peptide). Treatment lowered these proteins to below their risk thresholds, except for IL-6, which was lowered but remained at its risk threshold despite successful psoriasis skin treatment. In summary, 12 weeks of ustekinumab treatment reduced serum proteins present at levels associated with CV risk in psoriasis patients. Further studies can evaluate these proteins as potential ustekinumab-modulated biomarkers of CV risk in psoriasis and the impact of ustekinumab on CV risk reduction.

Updates on Laboratory Evaluation of Feline Cardiac Diseases

Laboratory tests can be altered in cardiovascular diseases and the investigation of specific tests or biomarkers may provide additional information about myocardial damage. Traditional laboratory tests, such as cell blood count, serum biochemistry, and coagulation, can be useful in investigating patients, but are not specific. However, markers like Troponin and Natriuretic Peptides may possibly furnish further data on myocardium damage and can be used in both studying and monitoring cats with cardiac disease. Moreover, the evaluation of the thyroid profile is very important as hyperthyroid cats concomitant cardiovascular diseases are very common and they can also be a direct consequence of endocrinopathy. The purpose of this manuscript is to provide the widest possible overview of what is present in the literature about the feline clinical pathology of heart diseases through a rational division of the main alterations of traditional tests and biomarkers.

Advances in Cardiovascular Biomarker Discovery

Cardiovascular diseases are the leading causes of mortality worldwide. Among them, hypertension and its pathological complications pose a major risk for the development of other cardiovascular diseases, including heart failure and stroke. Identifying novel and early stage biomarkers of hypertension and other cardiovascular diseases is of paramount importance in predicting and preventing the major morbidity and mortality associated with these diseases. Biomarkers of such diseases or predisposition to their development are identified by changes in a specific indicator’s expression between healthy individuals and patients. These include changes in protein and microRNA (miRNA) levels. Protein profiling using mass spectrometry and miRNA screening utilizing microarray and sequencing have facilitated the discovery of proteins and miRNA as biomarker candidates. In this review, we summarized some of the different, promising early stage protein and miRNA biomarker candidates as well as the currently used biomarkers for hypertension and other cardiovascular diseases. Although a number of promising markers have been identified, it is unlikely that a single biomarker will unambiguously aid in the classification of these diseases. A multi-marker panel-strategy appears useful and promising for classifying and refining risk stratification among patients with cardiovascular disease.

Circulating Biomarkers of Cell Adhesion Predict Clinical Outcome in Patients with Chronic Heart Failure

Cardiovascular inflammation and vascular endothelial dysfunction are involved in chronic heart failure (CHF), and cellular adhesion molecules are considered to play a key role in these mechanisms. We evaluated temporal patterns of 12 blood biomarkers of cell adhesion in patients with CHF. In 263 ambulant patients, serial, tri-monthly blood samples were collected during a median follow-up of 2.2 (1.4–2.5) years. The primary endpoint (PE) was a composite of cardiovascular mortality, HF hospitalization, heart transplantation and implantation of a left ventricular assist device and was reached in 70 patients. We selected the baseline blood samples in all patients, the two samples closest to a PE, or, for event-free patients, the last sample available. In these 567 samples, associations between biomarkers and PE were investigated by joint modelling. The median age was 68 (59–76) years, with 72% men and 74% New York Heart Association class I–II. Repeatedly measured levels of Complement component C1q receptor (C1qR), Cadherin 5 (CDH5), Chitinase-3-like protein 1 (CHI3L1), Ephrin type-B receptor 4 (EPHB4), Intercellular adhesion molecule-2 (ICAM-2) and Junctional adhesion molecule A (JAM-A) were independently associated with the PE. Their rates of change also predicted clinical outcome. Level of CHI3L1 was numerically the strongest predictor with a hazard ratio (HR) (95% confidence interval) of 2.27 (1.66–3.16) per SD difference in level, followed by JAM-A (2.10, 1.42–3.23) and C1qR (1.90, 1.36–2.72), adjusted for clinical characteristics. In conclusion, temporal patterns of C1qR, CDH5, CHI3L1, EPHB4, ICAM2 and JAM-A are strongly and independently associated with clinical outcome in CHF patients.

Inflammatory Biomarkers and Atherosclerosis

Atherosclerosis has been regarded as a form of chronic vascular inflammation. Numerous biomarkers associated with inflammation have been identified as novel targets to monitor atherosclerosis and cardiovascular risk. C-reactive protein (CRP) is one of the most actively studied and established inflammatory biomarkers for cardiovascular events. However, CRP response is triggered by many disorders unrelated to cardiovascular disease, which interferes with the clinical application. This review describes established and traditional inflammatory biomarkers including CRP as well as novel inflammatory biomarkers reflective of local atherosclerotic inflammation. In addition, we focus on the potential usefulness of inflammatory biomarkers in developing anti-atherosclerotic therapeutic approaches.

Platelet activation in cats with hypertrophic cardiomyopathy

BACKGROUND

Cats with hypertrophic cardiomyopathy (HCM) are at risk for development of systemic thromboembolic disease. However, the relationship between platelet activation state and cardiovascular parameters associated with HCM is not well described.

OBJECTIVES

To characterize platelet activation by flow cytometric evaluation of platelet P-selectin and semiquantitative Western blot analysis of soluble platelet-endothelial cell adhesion molecule-1 (sPECAM-1).

ANIMALS

Eight normal healthy cats (controls) owned by staff and students of the School of Veterinary Medicine and 36 cats from the UC Davis Feline HCM Research Laboratory were studied.

METHODS

Platelet-rich plasma (PRP) was used for all flow cytometry studies. Platelet surface CD41 and P-selectin expression were evaluated before and after ADP stimulation. sPECAM-1 expression was evaluated by Western blot analysis of platelet-poor plasma that had been stabilized with aprotinin. Standard echocardiographic studies were performed.

RESULTS

Resting platelets from cats with severe HCM had increased P-selectin expression compared to controls, and expressed higher surface density of P-selectin reflected by their increased mean fluorescence intensities (MFI). Stimulation with ADP also resulted in significantly increased P-selectin MFI of platelets from cats with severe HCM. Increased P-selectin expression and MFI correlated with the presence of a heart murmur and end-systolic cavity obliteration (ESCO). sPECAM-1 expression from cats with moderate and severe HCM was significantly increased above those of control cats.

CONCLUSIONS AND CLINICAL IMPORTANCE

P-selectin and sPECAM expression may be useful biomarkers indicating increased platelet activation in cats with HCM.

Platelet receptors

Well-understood functions for "traditional" platelet receptors are described, but "newer" receptors are equally discussed. Receptors are described biochemically (structure, ligand(s), protein partners, and function) and whenever possible, their clinical importance (mutations, polymorphisms, syndrome) are highlighted.

Leucine125Valine (Leu125Val) Gene Polymorphism of Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1) and Myocardial Infarction in Indian Population

Platelet-endothelial cell adhesion molecule-1 (PECAM-1) has role in atherosclerotic plaque development as well as in thrombosis leading to myocardial infarction (MI). Present study was aimed to analyse the association of PECAM-1 Leu125Val gene polymorphism with MI in Indian population. Subjects included healthy individuals as control (N = 116) and MI patients (N = 100) divided into two groups; MI patients at presentation of the acute event (MI-Group-1, N = 46) and patients with recent event of MI stabilized with treatment 4.5 days from their symptoms (MI-Group-2, N = 54). The difference in the distribution of Leu125Val genotype frequencies of controls and patients did not reach statistical significance. However Leu allele frequency (0.57) was more associated with MI patients as compared to control (0.504). sPECAM-1 levels were significantly elevated in patients at acute event of MI (MI-Group-1) by 44.1% (P = 0.009) as compared to controls and by 95.2% (P = 0.001) as compared to stabilized MI patients (MI-Group-2).

Platelet reactivity and the identification of acute coronary syndromes in the emergency department

Risk stratifying patients with potential acute coronary syndromes (ACS) in the Emergency Department is an imprecise and resource-consuming process. ACS cannot be ruled in or out efficiently in a majority of patients after initial history, physical exam, and ECG are analyzed. This has led to a reliance on cardiac markers of myocardial necrosis as a key means of making the diagnosis. Commonly used markers, CK-MB and troponin-I, have the drawback of delayed sensitivity. This has led to an ongoing search for one or more marker(s) that would be more sensitive in early ACS. With the central role that platelets play in the pathophysiology of coronary thrombosis, measures of platelet function represent one potential area where an early ACS marker might be identified. This review will focus on selected tests/markers of platelet function that have shown some promise with respect to the risk stratification of patients with potential ACS.

Elevation of matrix metalloproteinases and interleukin-6 in the culprit coronary artery of myocardial infarction

BACKGROUND

Interleukin-6 (IL-6) and metalloproteinases (MMPs) are involved in the instability of vulnerable plaque associated with the induction of acute myocardial infarction (AMI). We examined the regional changes of cytokines, MMPs and adhesion molecules in patients with AMI to elucidate how these factors are involved in the onset of AMI.

MATERIALS AND METHODS

One hundred and twenty-two patients with AMI were included. Blood was aspirated from the culprit coronary artery with a thrombectomy catheter, and was also sampled from peripheral veins during the coronary intervention. Control samples were obtained from the peripheral blood of age-matched patients.

RESULTS

The serum levels of IL-6 (P < 0.05), tumour necrosis factor-alpha (P < 0.005), MMP-1 (P < 0.001), MMP-13 (P < 0.001), soluble intercellular adhesion molecule-1 (P < 0.005), and soluble vascular cellular adhesion molecule-1 (P < 0.05) in peripheral blood were significantly higher in the AMI group than in the controls. Aspirated serum contained significantly higher levels of IL-6 (P < 0.001), MMP-1 (P < 0.001), and MMP-13 (P < 0.05) compared to the peripheral blood of AMI. Serum IL-6 levels were significantly higher in the aspirated than in the peripheral blood in the patients hospitalized within 6 h and 6-12 h, but were similar in the aspirated and peripheral blood of the patients hospitalized 12-24 h after the onset of AMI. There were no differences between the aspirated serum and peripheral blood in the levels of interleukin-1beta and MMP-2.

CONCLUSIONS

The levels of MMP-1, MMP-13 and IL-6 were higher in the culprit coronary artery than in the peripheral blood. These factors appear to be involved in the early stage of AMI.

The effect of sulphonylureas on the microvascular and macrovascular complications of diabetes

INTRODUCTION

Type 2 diabetes mellitus is a chronic progressive disease that is characterised by hyperglycaemia and is associated with an increased risk of the development of microvascular complications, such as retinopathy, nephropathy and neuropathy, and cardiovascular disease. With the introduction of newer oral hypoglycaemic agents, there is a need to re-evaluate critically the effectiveness and safety of the older agents, including sulphonylureas, to assess their place in the modern management of type 2 diabetes.

BACKGROUND

Though no clear benefit of sulphonylureas has been shown with respect to large vessel disease, long term studies have, however, shown benefits in patients with microvascular complications. Studies such as the University Group Diabetes Project raised concerns about the safety profile of sulphonylureas, but large prospective studies such as the UK Prospective Diabetes Study have helped to assuage such concerns to a large degree. Their utility in the peri-infarct period continues to be debatable because of the potential effect on cardiac pre-conditioning.

CONCLUSION

Though sulphonylureas continue to be a mainstay of treatment in type 2 diabetes, future clinical trials addressing clinically relevant outcomes are indicated with the newer generation of sulphonylureas that are more beta cell-specific to address the concerns raised about sulphonylureas and cardiac myocytes.

Change in platelet endothelial cell adhesion molecule-1 immunoreactivity in the dentate gyrus in gerbils fed a folate-deficient diet

Folate deficiency increases stroke risk. We examined whether folate deficiency affects platelet endothelial cell adhesion molecule-1 (PECAM-1), which is an immunoglobulin-associated cell adhesion molecule and mediates the final common pathway of neutrophil transendothelial migration, in blood vessels in the gerbil dentate gyrus after transient forebrain ischemia. Gerbils were exposed to a folic acid-deficient diet (FAD) for 3 months and then subjected to common carotid artery occlusion for 5 min. In the control diet (CD)- and FAD-treated sham-operated groups, weak PECAM-1 immunoreactivity was detected in the blood vessels located in the dentate gyrus. PECAM-1 immunoreactivity in both groups was increased by 4 days after ischemic insult. PECAM-1 immunoreactivity in the FAD-treated group was twice as high that in the CD-treated-sham-operated group 4 days after ischemic insult. Western blot analyses showed that the change patterns in PECAM-1 protein levels in the dentate gyrus in both groups after ischemic insult were similar to changes in PECAM-1 immunohistochemistry in the ischemic dentate gyrus. Our results suggest that folate deficiency enhances PECAM-1 in the dentate gyrus induced by transient ischemia.

Short-term sPECAM-Fc treatment ameliorates EAE while chronic use hastens onset of symptoms

The homophilic cell adhesion molecule PECAM-1 is a major participant in the migration of leukocytes across endothelium. We examined the ability of a chimeric soluble PECAM-1 fused to human IgG-Fc to impair leukocyte entry through the blood-brain barrier and reduce CNS autoimmunity. sPECAM-Fc impaired migration of lymphocytes across brain endothelial monolayers and diminished the severity of EAE, an experimental model of MS, when administered at the onset of symptoms. However, in mice transgenic for sPECAM-Fc, the chronically elevated levels of sPECAM-Fc hastened onset of EAE disease without significantly changing clinical score severity. Our data suggest that short-term treatment of diseases like MS with sPECAM-Fc has therapeutic potential.

Direct Effect of F12511, A Systemic Inhibitor of Acyl-CoA Cholesterol Acyltransferase on Bovine Aortic Endothelial Cells

F12511(S)-2',3',5'-trimethyl-4'-hydroxy-alpha-dodecylthio-alpha-phenylacetanilide (F12511) is a new Acyl-CoA cholesterol acyltransferase (ACAT) inhibitor that not only reduces the plasma cholesterol levels but also has anti-atherosclerotic actions in animals models. The study's aim was to analyze if F12511 may directly modify the ability of tumor necrosis factor--alpha (TNF-alpha)-incubated bovine aortic endothelial cells (BAEC) to express endothelial nitric oxide synthase (eNOS) protein and inflammatory-related proteins such as platelet endothelial cell adhesion molecule (PECAM) and CD40 ligand (CD40L). The addition of increasing concentrations of F12511 (10 to 10 mol/L) failed to modify the level of eNOS protein expressed in control BAEC. TNF-alpha (10 ng/mL) reduced the expression of eNOS protein. In TNF-alpha--incubated BAEC, F12511 protected eNOS expression in a concentration-dependent manner. TNF-alpha stimulated the expression of both CD40L and PECAM in cultured BAEC. F12511 (10 mol/L) failed to modify the expression of CD40L and PECAM in control and TNF-alpha-incubated BAEC. Reverse transcriptase polymerase chain reaction showed a marked expression of the ACAT-2 isoform and absent of expression of the ACAT-1 isoform in BAEC. The presence of ACAT-2 isoform in BAEC was further confirmed by Western blot. F12511 failed to modify the expression of the proinflammatory associated proteins PECAM and CD40L in the endothelium but protected eNOS expression in the endothelial cells exposed to inflammatory conditions.

Reduction of soluble P-selectin by statins is inversely correlated with the progression of coronary artery disease

BACKGROUND

Cell adhesion molecules (CAM) play an important role in the pathogenesis of atherosclerosis by mediating the binding of leukocytes to the endothelium. Soluble CAM isoforms are known to be elevated in the sera of patients suffering from coronary artery disease (CAD).

METHODS

We measured the concentrations of soluble intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, P-selectin, platelet endothelial cell adhesion molecule-1, and highly sensitive C-reactive protein (hs-CRP) in the blood of 47 CAD patients before and 6 months after starting statin therapy and in 16 untreated CAD patients. The progression of CAD was monitored by calculating the coronary calcium score using electron beam computed tomography.

RESULTS

Soluble P-selectin (92+/-11 ng/ml vs. 59 +/- 4 ng/ml, p < 0.0001) and hs-CRP (0.92 +/- 0.14 mg/dl vs. 0.42 +/- 0.11 mg/dl, p < 0.001) decreased significantly in the statin-treated group compared to baseline levels. None of the other proteins studied showed significant changes. In contrast to hs-CRP, the reduction of soluble P-selectin concentrations correlated directly with the lowering of total cholesterol (r(2) = 0.236, p < 0.005) and inversely with the progression of CAD (r(2) = 0.393, p < 0.0001).

CONCLUSIONS

Our results suggest P-selectin as an additional marker for the beneficial action of statins in patients with CAD.

Ischemia-induced changes of platelet endothelial cell adhesion molecule-1 in the hippocampal CA1 region in gerbils

We observed chronological changes of platelet endothelial cell adhesion molecule-1 (PECAM-1), final mediator of neutrophil transendothelial migration, immunoreactivity, and protein level in the gerbil hippocampus proper after 5 min of transient ischemia. One day after ischemic insult, PECAM-1 immunoreactivity and protein level increased slightly in the hippocampus proper. Thereafter, PECAM-1 immunoreactivity and protein level increased significantly in the hippocampus proper by 4 days after ischemic insult. Especially, PECAM-1 in the hippocampal CA1 region was higher than that in the CA2/3 region. Five days after ischemic insult, PECAM-1 immunoreactivity decreased compared to the 4 days post-ischemic group. However, the RNA levels of PECAM-1 in the hippocampus proper were significantly decreased in the 4 days post-ischemic groups compared to that in the sham-operated group. This result suggests that the increase of PECAM-1 and decrease of PECAM-1 RNA in the CA1 region 4 days after ischemia may be associated with transmigration of neurotrophil.

Cleavage of platelet endothelial cell adhesion molecule-1 (PECAM-1) in platelets exposed to high shear stress

Platelet endothelial cell adhesion molecule-1 (PECAM-1, CD31) is a 130 kDa transmembrane glycoprotein that belongs to the immunoglobulin superfamily and is expressed on the surface of endothelial cells, platelets, and other blood cells. Although the importance of this adhesion molecule in various cell-cell interactions is established, its functional role in platelets remains to be elucidated. In this study, we examined whether PECAM-1 underwent changes in platelets exposed to high shear stress. Platelet PECAM-1 was cleaved under high shear stress and was released into the extracellular fluid as a fragment with an approximate molecular weight of 118 kDa. The cleavage was inhibited by an anti-VWF MoAb, but not by recombinant VWF A1 domains. These findings suggest that the GPIb-VWF interaction is involved in PECAM-1 cleavage under high shear stress, and that the cleavage is independent of GPIb clustering by VWF multimers. Furthermore, EGTA or calpeptin inhibited PECAM-1 cleavage. This finding provides evidence for the involvement of calpain in PECAM-1 cleavage. Flow-cytometric analysis revealed that PECAM-1 expression on the platelet surface was decreased under high shear stress. This reduction occurred exclusively in a specific population of platelets, which corresponded to platelet-derived microparticles (PMP). In conclusion, PECAM-1 cleavage under high shear stress is closely related to the activation of calpain and the process of PMP formation mediated by the GPIb-VWF interaction.