Dorette Raaz

Patients with acute coronary syndromes express enhanced CD40 ligand/CD154 on platelets

OBJECTIVE To investigate whether CD40L/CD154 on platelets and soluble CD40L/CD154 may play a role in the inflammatory process of acute coronary syndromes. DESIGN AND SETTING Observational study in a university hospital. PATIENTS 15 patients with acute myocardial infarction, 25 patients with unstable angina, 15 patients with stable angina, and 12 controls. MAIN OUTCOME MEASURES CD40L/CD154 on platelets, P-selectin/CD62P on platelets, soluble CD40L/CD154 serum concentrations. RESULTS Mean (SD) CD40L/CD154 expression on platelets was 6.2 (2.8) MFI (mean fluorescence intensity) in the infarct group, 11 (3.3) MFI in the unstable angina group (p < 0.001 v infarction), 3.6 (0.9) MFI in the stable angina group (p < 0.01 vinfarction; p < 0.001 v unstable angina), and 3.2 (1.0) MFI in the controls (p < 0.01v infarction; p < 0.001v unstable angina; NSv stable angina). Soluble CD40L/CD154 concentration was 5.2 (1.1) ng/ml in the infarct group, 4.2 (0.7) ng/ml in the unstable angina group (p < 0.001v infarction), 2.9 (1.0) ng/ml in stable angina group (p < 0.001 v infarction and unstable angina), and 3.0 (0.5) ng/ml in the controls (p < 0.001v infarction and unstable angina; NSv stable angina). At a six months follow up, there was lower expression of CD40L/CD154 on platelets in patients with unstable angina (12.3 (3.6) v 3.8 (1.2) MFI, p < 0.0001) and acute myocardial infarction (6.2 (2.8)v 3.5 (0.8) MFI, p < 0.01) compared with their admission values six months earlier. Patients with unstable angina who needed redo coronary angioplasty (PTCA) or who had recurrence of angina were characterised by increased CD40L/CD154 expression on platelets compared with the remainder of the study group (recurrence of angina: 12.7 (3.2) v 9.7 (1.6) MFI, p < 0.05; re-do PTCA: 14.3 (4.2) v10.3 (2.1) MFI, p < 0.05). CONCLUSIONS Both CD40L/CD154 on platelets and soluble CD40L/CD154 are raised in patients with unstable angina and myocardial infarction. These findings suggest that CD40–CD40L/CD154 interactions may play a pathogenic role in triggering and propagation of acute coronary syndromes.

Enhanced levels of platelet P-selectin and circulating cytokines in young patients with mild arterial hypertension.

Background Emerging evidence links inflammation to atherosclerosis (AS). Although some studies have addressed the role of inflammation in patients with arterial hypertension (AH), its overall contribution in AH is far from being understood. Therefore, the present pilot study was designed to examine the role of platelet P-selectin and various inflammatory mediators in young patients with moderate AH without signs of target organ damage. Methods and results Fifteen patients with mild AH [33.8 ± 7.3 years, mean arterial pressure (MAP) 106.6 ± 10.4 mmHg] and 15 healthy normotensive controls (31.7 ± 10.6 years) were examined. Platelet P-selectin was analysed by flow cytometry. Plasma levels of monocyte-chemoattractant-protein-1 (MCP-1), high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, tumour necrosis factor α (TNFα), and IL-10 levels were measured by enzyme immunoassay (EIA). Patients with mild AH showed significantly enhanced expression of platelet P-selectin [17.2 ± 5.4 versus 10.6 ± 4.2 mean fluorescence intensity (MFI), P < 0.001]. P-selectin expression positively correlated with MAP (r = 0.43, P < 0.05). Furthermore, patients with mild AH had significantly enhanced plasma levels of hsCRP (2.7 ± 3.8 versus 0.6 ± 0.9 mg/l, P < 0.01), IL-6 (1.4 ± 0.7 versus 0.6 ± 0.3 pg/ml, P < 0.001), TNFα (2.8 ± 0.7 versus 2.4 ± 0.4 pg/ml, P < 0.05), and MCP-1 (291.3 ± 100.7 versus 214.3 ± 8.3 pg/ml, P < 0.05). IL-6 levels positively correlated with hsCRP levels (r = 0.47, P < 0.05) and mean arterial pressure (MAP) (r = 0.44, P < 0.05). Conclusions This pilot study demonstrates that in an early stage of AH, inflammatory pathways are already activated. Besides pro-inflammatory cytokines, platelets seem to play a significant role in mediating inflammation in AH, which could lead to target organ injury. Further investigations have to clarify the role of early anti-inflammatory therapy, in patients with mild to moderate AH, in alleviating hypertensive target organ damage.

Enhanced levels of CD154 (CD40 ligand) on platelets in patients with chronic heart failure

Inflammation plays a significant contributory role in the pathogenesis of chronic heart failure (CHF). Previous data have shown enhanced plasma levels of proinflammatory cytokines, i.e. TNF‐α and IL‐6, as well as a persistent immune activation in patients with CHF. Furthermore, the immune modulator CD154 has been receiving increased attention, since it plays a key role in the pathophysiology of multicellular vascular events such as thrombosis, inflammation and atherosclerosis. Since CD154 intitiates and maintains the release of proinflammatory cytokines from endothelial cells, its potential role for the development and progression of CHF is of interest.

Delay of neutrophil apoptosis in acute coronary syndromes

Apoptosis of polymorphonuclear neutrophils (PMN) is currently discussed as a key event in the control of inflammation. This study determined PMN apoptosis and its underlying mechanisms in controls (C), patients with stable (SAP) or unstable angina (UAP), and with acute myocardial infarction (AMI). Blood was drawn from 15 subjects of each C, SAP, UAP, and AMI. Apoptosis was measured by flow cytometry in isolated PMN (propidium iodide staining) and PMN from whole blood (CD16, FcγRIII). Serum cytokines were determined by enzyme‐linked immunosorbent assay. Apoptosis of isolated PMN was delayed significantly in acute coronary syndromes (ACS) as compared with SAP or C (C, 51.2±12.6%; SAP, 44.9±13.6%; UAP, 28.4±10.1%; AMI, 20.3±8.5%; AMI or UAP vs. SAP or C, P<0.001). These results were confirmed by measurement of PMN apoptosis in cultured whole blood from patients and controls. Moreover, serum of patients with ACS markedly reduced apoptosis of PMN from healthy donors. Analysis of patients’ sera revealed significantly elevated concentrations of tumor necrosis factor α, interferon‐γ (IFN‐γ), granulocyte macrophage‐colony stimulating factor (GM‐CSF), and interleukin (IL)‐1β in ACS (vs. C and SAP). IFN‐γ, GM‐CSF, and IL‐1β significantly delayed PMN apoptosis in vitro. Furthermore, coincubation of PMN with adenosine 5′‐diphosphate‐activated platelets significantly inhibited PMN apoptosis as compared with coculture with unstimulated platelets. This study demonstrates a pronounced delay of PMN apoptosis in UAP and AMI, which may result from increased serum levels of IFN‐γ, GM‐CSF, and IL‐1β and from enhanced platelet activation. Therapeutical modulation of these determinants of PMN lifespan may provide a new concept for the control of inflammation in ACS.

Interleukin-10 improves left ventricular function in rats with heart failure subsequent to myocardial infarction.

Evidence has shown that pro‐inflammatory cytokines, especially TNF‐α, are involved in the inflammatory response in the remodelling process after myocardial infarction (MI). Although IL‐10, an anti‐inflammatory cytokine, has been shown to antagonize some of the deleterious effects of TNF‐α, little is known about its role in post‐MI left ventricular (LV) dysfunction. The aim of the present study was to investigate whether a therapy with rhIL‐10 could be beneficial in an animal model of post‐MI heart failure (HF).

Shear stress preconditioning modulates endothelial susceptibility to circulating TNF-α and monocytic cell recruitment in a simplified model of arterial bifurcations

OBJECTIVE Atherosclerotic plaque formation results from a combination of local shear stress patterns and inflammatory processes. This study investigated the endothelial response to shear stress in combination with the inflammatory cytokine TNF-alpha in a simplified model of arterial bifurcation. METHODS Human umbilical vein endothelial cells (ECs) were exposed to laminar or non-uniform shear stress in bifurcating flow-through slides, followed by stimulation with TNF-alpha. To study cell adhesion, ECs were perfused with medium containing THP-1 monocytic cells. Endothelial protein expression was determined by immunofluorescence. RESULTS Adhesion of monocytic cells to unstimulated ECs was nearly undetectable under laminar shear stress and was slightly increased under non-uniform shear stress. Exposure of ECs to non-uniform shear stress in combination with TNF-alpha induced a 12-fold increase in monocytic cell recruitment and a significant induction of endothelial E-selectin and VCAM-1 expression. Both these effects were prevented in ECs exposed to laminar shear stress. The significant differences in TNF-alpha-induced monocytic cell recruitment and adhesion molecule expression between laminar and non-uniform shear stress regions were abolished in the absence of shear stress preconditioning. Simvastatin (1 micromol/L) suppressed the non-uniform shear stress- and TNF-alpha-induced increase in monocytic cell adhesion by about 30% via inhibition of VCAM-1 expression. Resveratrol, the active component of red wine, inhibited the expression of both VCAM-1 and E-selectin, and reduced monocytic cell recruitment by 50% at 20 micromol/L. CONCLUSIONS Non-uniform shear stress induces endothelial susceptibility to circulating TNF-alpha and adhesion of monocytic cells. Interference with this process may inhibit inflammatory response in atherosclerosis-prone regions.

Atorvastatin enhances interleukin-10 levels and improves cardiac function in rats after acute myocardial infarction.

LV (left ventricular) remodelling is the basic mechanism of HF (heart failure) following MI (myocardial infarction). Although there is evidence that pro-inflammatory cytokines [including TNF-alpha (tumour necrosis factor-alpha) and IL-6 (interleukin-6)] are involved in the remodelling process, only little is known about the role of anti-inflammatory cytokines, such as IL-10. As accumulating evidence has revealed that statins possess anti-inflammatory properties, the aim of the present study was to elucidate the effect of atorvastatin on the modulation of the anti-inflammatory cytokine IL-10 and its effect on LV function in rats with HF subsequent to MI. Rats with MI, induced by permanent LAD (left anterior descending) branch coronary artery ligation, were treated for 4 weeks with atorvastatin (10 mg x kg(-1) of body weight x day(-1) via oral gavage) starting on the first day after induction of MI. Cardiac function was assessed by echocardiography and cardiac catheterization 4 weeks after MI induction. Membrane-bound and soluble fractions of TNF-alpha, IL-6 and IL-10 protein, the TNF-alpha/IL-10 ratio, serum levels of MCP-1 (monocyte chemoattractant protein-1) as well as myocardial macrophage infiltration were analysed. Treatment with atorvastatin significantly improved post-MI LV function (fractional shortening, +120%; dP/dt(max), +147%; and LV end-diastolic pressure, -27%). Furthermore atorvastatin treatment markedly decreased the levels of TNF-alpha, IL-6 and MCP-1, reduced myocardial infiltration of macrophages and significantly increased myocardial and serum levels of the anti-inflammatory cytokine IL-10. Thus the balance between pro-inflammatory and anti-inflammatory cytokines was shifted in the anti-inflammatory direction, as shown by a significantly decreased TNF-alpha/IL-10 ratio. Atorvastatin ameliorated early LV remodelling and improved LV function in rats with HF subsequent to MI. Our study suggests that the modulation of the balance between pro- and anti-inflammatory cytokines towards the anti-inflammatory cytokine IL-10 is one salutary mechanism underlying how atorvastatin influences post-MI remodelling and thus improves LV function.

Anti-Inflammatory Effects of Danshen on Human Vascular Endothelial Cells in Culture

Inflammation plays a crucial role in the pathophysiology of atherosclerosis. Besides cytokines, chemokines and cell adhesion molecules, CD40 and P-selectin play important roles as key regulators of the inflammatory process in atherosclerosis. Danshen (DS) is commonly used in traditional Chinese medicine for therapy of cardiovascular diseases such as coronary artery disease. The aim of the present study was to evaluate the protective effects of DS with respect to possible anti-inflammatory effects. Human umbilical vein endothelial cells as well as platelets were incubated with an extract of DS or one of its major ingredients salvianolic acid B (Sal B), tanshinone IIA (Tansh) and protocatechuic acid (Protoc) under tumor necrosis factor (TNF)-α or ADP stimulation. Expression of CD40 and cellular adhesion molecules (VCAM-1/ICAM-1) were assessed via flow cytometry. Levels of interleukin (IL)-6, IL-8, monocyte-chemoattractant-protein (MCP)-1 as well as soluble VCAM1 and ICAM-1 in the supernatants were examined via luminex based analysis. Treatment with DS attenuated TNF-α induced expression of CD40. Furthermore, the expression of VCAM-1 and ICAM-1 as well as the release of soluble VCAM-1 and ICAM-1 were downregulated. In the cell supernatants we also observed a significant reduction of IL-6, IL8 and MCP-1. DS and its major ingredients, Sal B and Protoc, significantly inhibited TNF-induced expression and release of adhesion molecules, cytokines and chemokines as well as ADP-induced expression of platelet P-selectin. Because of the key roles of inflammatory mediators in the etiology of atherosclerosis, this work provides useful insight in understanding the pharmacological efficacy of Chinese herbal medicine.

Elevated VEGF‐plasma levels in young patients with mild essential hypertension

Background  Growing evidence shows that inflammation plays a pivotal role in the pathophysiology of essential hypertension (EH). Vascular endothelial cell growth factor (VEGF) is currently discussed as a possible mediator of inflammation. To investigate the hypothesis that VEGF plays a role as an inflammatory mediator in EH we performed the present pilot study of young patients in a very early stage of EH.

CD40/CD154 system and pro-inflammatory cytokines in young healthy male smokers without additional risk factors for atherosclerosis.

Abstract.Objective and design:Atherosclerosis, as an inflammatory disease, is characterized by pathologically altered levels of cytokines. We investigated whether smoking affects the CD40/CD154 system and pro-inflammatory cytokines in young males without other risk factors for atherosclerosis.Subjects:Young male smokers (n=13) and 14 non-smoking controls were investigated.Methods:The differences in CD40/CD154 system and serum cytokines between the groups were measured using flow cytometry and ELISA.Results:In smokers, there was a strong trend (P<0.06) for increased CD40 expression on platelets as compared with non-smokers. However, there were no significant differences in CD40 expression on monocytes or in CD154 expression on platelets and T-cells between smokers and non-smokers. There was a strong trend for increased platelet-monocyte aggregates in smokers (P<0.06). Also, smokers had slightly but not significantly elevated hsCRP and IL-6 levels, and slightly decreased TNF-α and MCP-1. Interestingly, IL-18, a cytokine which has the ability to promote both Th1 and Th2 responses, was significantly decreased in smokers group (P=0.03 vs controls).Conclusions:In young healthy males, smoking is not associated with dramatic changes in CD40/CD154 system. However, cigarette smoke alters the secreted cytokine profile, leading to significant decrease in systemic IL-18 levels.