Interleukin 27 is increased in carotid atherosclerosis and promotes NLRP3 inflammasome activation.

AIM: Interleukin-27 (IL-27) is involved in different inflammatory diseases; however, its role in atherosclerosis is unclear. In this study we investigated the expression of IL-27 and its receptor in patients with carotid atherosclerosis and if IL-27 could modulate the inflammatory effects of the NLRP3 inflammasome in vitro. METHODS: Plasma IL-27 was measured by enzyme immunoassay in patients with carotid stenosis (n = 140) and in healthy controls (n = 19). Expression of IL-27 and IL-27R was analyzed by quantitative PCR and immunohistochemistry in plaques from patients and in non-atherosclerotic vessels. THP-1 monocytes, primary monocytes and peripheral blood mononuclear cells (PBMCs) were used to study effects of IL-27 in vitro. RESULTS: Our main findings were: (i) Plasma levels of IL-27 were significantly elevated in patients with carotid atherosclerotic disease compared to healthy controls. (ii) Gene expression of IL-27 and IL-27R was significantly elevated in plaques compared to control vessels, and co-localized to macrophages. (iii) In vitro, IL-27 increased NLRP3 inflammasome activation in monocytes with enhanced release of IL-1 ß. CONCLUSIONS: We demonstrate increased levels of IL-27 and IL-27R in patients with carotid atherosclerosis. Our in vitro findings suggest an inflammatory role for IL-27, which can possibly be linked to atherosclerotic disease development.

Wnt5a is associated with right ventricular dysfunction and adverse outcome in dilated cardiomyopathy.

The Wingless (Wnt) pathway has been implicated in the pathogenesis of dilated cardiomyopathy (DCM). To explore the role of Wnt modulators Wnt5a and sFRP3 in DCM patients we analyzed the expression of Wnt5a and sFRP3 in plasma and myocardium of DCM patients and evaluated their effects on NFAT luciferase activity in neonatal mouse cardiomyocytes. Elevated circulating Wnt5a (n = 102) was associated with increased pulmonary artery pressures, decreased right ventricular function and adverse outcome, with a stronger association in more severely affected patients. A higher Wnt5a/sFRP3 ratio (n = 25) was found in the right ventricle vs. the left ventricle and was correlated with NFAT activation as well as pulmonary artery pressures. Wnt5a induced NFAT activation and sFRP3 release in cardiomyocytes in vitro, while sFRP3 antagonized Wnt5a. Wnt5a is associated with right ventricular dysfunction and adverse outcome in DCM patients and may promote the progression of DCM through NFAT signaling.

Wnt5a is elevated in heart failure and affects cardiac fibroblast function.

Wnt signaling is dysregulated in heart failure (HF) and may promote cardiac hypertrophy, fibrosis, and inflammation. Blocking the Wnt ligand Wnt5a prevents HF in animal models. However, the role of Wnt5a in human HF and its functions in cardiac cells remain unclear. Here, we investigated Wnt5a regulation in HF patients and its effects on primary mouse and human cardiac fibroblasts. Serum Wnt5a was elevated in HF patients and associated with hemodynamic, neurohormonal, and clinical measures of disease severity. In failing human hearts, Wnt5a protein correlated with interleukin (IL)-6 and tissue inhibitor of metalloproteinase (TIMP)-1. Wnt5a messenger RNA (mRNA) levels were markedly upregulated in failing myocardium and both mRNA and protein levels declined following left ventricular assist device therapy. In primary mouse and human cardiac fibroblasts, recombinant Wnt5a dose-dependently upregulated mRNA and protein release of IL-6 and TIMP-1. Wnt5a did not affect ß-catenin levels, but activated extracellular signal-regulated kinase 1/2 (ERK1/2) signaling. Importantly, inhibition of ERK1/2 activation attenuated Wnt5a-induced release of IL-6 and TIMP-1. In conclusion, our results show that Wnt5a is elevated in the serum and myocardium of HF patients and is associated with measures of progressive HF. Wnt5a induces IL-6 and TIMP-1 in cardiac fibroblasts, which might promote myocardial inflammation and fibrosis, and thereby contribute to HF progression. KEY MESSAGES: • Wnt5a is elevated in serum and myocardium of HF patients and is associated with measures of progressive HF. • In cardiac fibroblasts, Wnt5a upregulates interleukin (IL)-6 and tissue inhibitor of metalloproteinase (TIMP)-1 through the ERK pathway. • Wnt5a-mediated effects might promote myocardial inflammation and fibrosis, and thereby contribute to HF progression.

Inflammatory cytokines as biomarkers in heart failure.

Inflammation has been implicated in the pathogenesis of heart failure (HF). In addition to their direct involvement as mediators in the pathogenesis of HF, inflammatory cytokines and related mediators could also be suitable markers for risk stratification and prognostication in HF patients. Many reports have suggested that inflammatory cytokines may predict adverse outcome in these patients. However, most studies have been limited in sample size and lacking full adjustment with the most recent and strongest biochemical predictor such as NT-proBNP and high sensitivity troponins. Furthermore, a number of pre-analytical and analytical aspects of cytokine measurements may limit their use as biomarkers. This review focuses on technical, informative and practical considerations concerning the clinical use of inflammatory cytokines as prognostic biomarkers in HF. We focus on the predictive value of tumor necrosis factor (TNF) α, the TNF family receptors sTNFR1 and osteoprotegerin, interleukin (IL)-6 and its receptor gp130, the chemokines MCP-1, IL-8, CXCL16 and CCL21 and the pentraxin PTX-3 in larger prospective fully adjusted studies. No single inflammatory cytokine provides sufficient discrimination to justify the transition to everyday clinical use as a prognosticator in HF. However, while subjecting potential new HF markers to rigorous comparisons with "gold-standard" markers, such as NT-proBNP, using receiver operating characteristics (ROCs) and HF risk models, makes sense from a clinical standpoint, it may pose a threat to a broadening of mechanistic insight if the new markers are dismissed solely on account of lower statistical power.

The homeostatic chemokine CCL21 predicts mortality in aortic stenosis patients and modulates left ventricular remodeling.

BACKGROUND: CCL21 acting through CCR7, is termed a homeostatic chemokine. Based on its role in concerting immunological responses and its proposed involvement in tissue remodeling, we hypothesized that this chemokine could play a role in myocardial remodeling during left ventricular (LV) pressure overload. METHODS AND RESULTS: Our main findings were: (i) Serum levels of CCL21 were markedly raised in patients with symptomatic aortic stenosis (AS, n = 136) as compared with healthy controls (n = 20). (ii) A CCL21 level in the highest tertile was independently associated with all-cause mortality in these patients. (iii) Immunostaining suggested the presence of CCR7 on macrophages, endothelial cells and fibroblasts within calcified human aortic valves. (iv). Mice exposed to LV pressure overload showed enhanced myocardial expression of CCL21 and CCR7 mRNA, and increased CCL21 protein levels. (v) CCR7-/- mice subjected to three weeks of LV pressure overload had similar heart weights compared to wild type mice, but increased LV dilatation and reduced wall thickness. CONCLUSIONS: Our studies, combining experiments in clinical and experimental LV pressure overload, suggest that CCL21/CCR7 interactions might be involved in the response to pressure overload secondary to AS.

The effect of rosuvastatin on inflammation, matrix turnover and left ventricular remodeling in dilated cardiomyopathy: a randomized, controlled trial.

BACKGROUND: Dilated cardiomyopathy is characterized by left ventricular dilatation and dysfunction. Inflammation and adverse remodeling of the extracellular matrix may be involved in the pathogenesis. Statins reduce levels of low density lipoprotein cholesterol, but may also attenuate inflammation and affect matrix remodeling. We hypothesized that treatment with rosuvastatin would reduce or even reverse left ventricular remodeling in dilated cardiomyopathy. MATERIALS AND METHODS: In this multicenter, randomized, double blind, placebo-controlled study, 71 patients were randomized to 10 mg of rosuvastatin or matching placebo. Physical examination, blood sampling, echocardiography and cardiac magnetic resonance imaging were performed at baseline and at six months' follow-up. The pre-specified primary end point was the change in left ventricular ejection fraction from baseline to six months. RESULTS: Over all, left ventricular ejection fraction improved 5 percentage points over the duration of the study, but there was no difference in the change in left ventricular ejection fraction between patients allocated to rosuvastatin and those allocated to placebo. Whereas serum low density lipoprotein cholesterol concentration fell significantly in the treatment arm, rosuvastatin did not affect plasma or serum levels of a wide range of inflammatory variables, including C-reactive protein. The effect on markers of extracellular matrix remodeling was modest. CONCLUSION: Treatment with rosuvastatin does not improve left ventricular ejection fraction in patients with dilated cardiomyopathy. TRIAL REGISTRATION: ClinicalTrials.gov NCT00505154.

Inflammatory cytokines in chronic heart failure: interleukin-8 is associated with adverse outcome. Results from CORONA.

AIM: We investigated the ability of prototypical inflammatory cytokines to predict clinical outcomes in a large population of patients with chronic systolic heart failure (HF). METHODS AND RESULTS: Serum levels of tumour necrosis factor-α (TNF-α), soluble TNF receptors type I and II (sTNF-RI and sTNF-RII), and the chemokines monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) were analysed in 1464 patients with chronic ischaemic systolic HF in the CORONA study, aged ≥ 60 years, in NYHA class II-IV, and related to the primary endpoint (n = 320), as well as any coronary event (n = 255), all-cause mortality (n = 329), cardiovascular (CV) mortality (n = 268), and the composite endpoint hospitalization from worsening heart failure (WHF) or CV mortality (n = 547). TNF-α, sTNF-RI, sTNF-RII, and IL-8, but not MCP-1, were independent predictors of all endpoints except the coronary endpoint in multivariable models including conventional clinical variables. After further adjustment for estimated glomerular filtration rate, the ApoB/ApoA-1 ratio, NT-proBNP, and high-sensitivity C-reactive protein, only IL-8 remained a significant predictor of all endpoints (except the coronary endpoint), while sTNF- RI remained independently associated with CV mortality. Adding IL-8 to the full model led to a significant improvement in net reclassification for all-cause mortality and CV hospitalization, but only a borderline significant improvement for the primary endpoint, CV mortality, and the composite endpoint WHF hospitalization or CV mortality. CONCLUSION: Our study supports a relationship between IL-8 and outcomes in patients with chronic HF. However, the clinical usefulness of IL-8 as a biomarker in an unselected HF population is at present unclear.

Prognostic effect of high-sensitive troponin T assessment in elderly patients with chronic heart failure: results from the CORONA trial.

BACKGROUND: The incremental prognostic value of high-sensitive troponin T (hs-cTnT) in heart failure (HF) beyond that of high-sensitivity C-reactive protein and amino-terminal probrain natriuretic peptide is debated. We examined the prognostic value of hs-cTnT in a subgroup of patients from the Controlled Rosuvastatin Multinational Trial in HF (CORONA) study. METHODS AND RESULTS: Hs-cTnT as a risk factor for the primary end point (cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke; n=356), as well as all-cause mortality (n=366), cardiovascular mortality (n=299), and the composite of cardiovascular mortality and hospitalization from worsening of HF (n=465), was investigated in 1245 patients (≥60 years; New York Heart Association [NYHA] class II-IV, ischemic systolic HF) randomly assigned to 10 mg rosuvastatin or placebo. In multivariable analyses, adjusting for left ventricular ejection fraction, NYHA class, age, body mass index, diabetes mellitus, sex, intermittent claudication, heart rate, estimated glomerular filtration rate, apolipoprotein B/apolipoprotein A-1 ratio, amino-terminal probrain natriuretic peptide, high-sensitivity C-reactive protein, and hs-cTnT (both dichotomized according to the 99th percentile and as a continuous variable) was associated with all end points (primary end point: hazard ratio, 1.87 and 1.51, respectively, per SD change; P<0.001; all other end points: hazard ratio, 1.39-1.70). However, improved discrimination as assessed by C-statistics was only seen for the primary end point and all-cause mortality. CONCLUSIONS: Elevated hs-cTnT levels provide strong and independent prognostic information in older patients with chronic ischemic HF. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00206310.

Increased systemic and local interleukin 9 levels in patients with carotid and coronary atherosclerosis.

OBJECTIVE: Atherosclerosis is a chronic inflammatory disorder that involves a range of inflammatory mediators. Although interleukin (IL)-9 has been related to inflammation, there are at present no data on its role in atherosclerosis. Here we have examined IL-9 and IL-9 receptor (IL-9R) systemically and locally in patients with coronary and carotid atherosclerosis. METHODS: Plasma IL-9 was quantified by enzyme immunoassay and multiplex technology. IL-9 and IL-9R mRNA were quantified by real-time RT-PCR, and their localization within the lesion was assessed by immunohistochemistry. RESULTS: THE MAIN FINDINGS WERE: (i) Patients with carotid atherosclerosis had significantly raised IL-9 plasma levels compared with healthy controls (n = 28), with no differences between asymptomatic (n = 56) and symptomatic (n = 88) patients. (ii) On admission, patients with acute ST-elevation myocardial infarction (STEMI) (n = 42) had markedly raised IL-9 plasma levels which gradually declined during the first week post-MI. (iii) T cells and monocytes from patients with unstable angina (n = 17) had increased mRNA levels of IL-9 as compared with controls (n = 11). (iv) Carotid plaques (n = 68) showed increased mRNA levels of IL-9 and IL-9R compared to non-atherosclerotic vessels (n = 10). Co-localization to T cells (IL-9 and IL-9R) and macrophages (IL-9) were shown by immunohistochemistry. (v) IL-9 increased IL-17 release in peripheral blood mononuclear cells from patients with unstable angina (n = 5) and healthy controls (n = 5) with a particularly enhancing effect in cells from the patient group. CONCLUSION: Our findings show increased IL-9 levels in different atherosclerotic disorders both systemically and within the lesion, suggesting a role for the IL-9/IL-9R axis in the atherosclerotic process, potentially involving IL-17 mediated mechanisms. However, the functional consequences of these findings should be further investigated.

The NLRP3 inflammasome is up-regulated in cardiac fibroblasts and mediates myocardial ischaemia-reperfusion injury.

AIMS: Nucleotide-binding oligomerization domain-Like Receptor with a Pyrin domain 3 (NLRP3) is considered necessary for initiating a profound sterile inflammatory response. NLRP3 forms multi-protein complexes with Apoptosis-associated Speck-like protein containing a Caspase recruitment domain (ASC) and Caspase-1, which activate pro-interleukin-1ß (IL-1ß) and pro-IL-18. The role of NLRP3 in cardiac cells is not known. Thus, we investigated the expression and function of NLRP3 during myocardial ischaemia. METHODS AND RESULTS: Myocardial infarction (MI) was induced in adult C57BL/6 mice and Wistar rats by ligation of the coronary artery. A marked increase in NLRP3, IL-1ß, and IL-18 mRNA expression was found in the left ventricle after MI, primarily located to myocardial fibroblasts. In vitro studies in cells from adult mice showed that myocardial fibroblasts released IL-1ß and IL-18 when primed with lipopolysaccharide and subsequently exposed to the danger signal adenosine triphosphate, a molecule released after tissue damage during MI. When hearts were isolated from NLRP3-deficient mice, perfused and subjected to global ischaemia and reperfusion, a marked improvement of cardiac function and reduction of hypoxic damage was found compared with wild-type hearts. This was not observed in ASC-deficient hearts, potentially reflecting a protective role of other ASC-dependent inflammasomes or inflammasome-independent effects of NLRP3. CONCLUSION: This study shows that the NLRP3 inflammasome is up-regulated in myocardial fibroblasts post-MI, and may be a significant contributor to infarct size development during ischaemia-reperfusion.

Association of ficolin-3 with severity and outcome of chronic heart failure.

BACKGROUND: Inflammatory mechanisms involving complement activation has been shown to take part in the pathophysiology of congestive heart failure, but the initiating mechanisms are unknown. We hypothesized that the main initiator molecules of the lectin complement pathway mannose-binding lectin (MBL), ficolin-2 and ficolin-3 were related to disease severity and outcome in chronic heart failure. METHODS AND RESULTS: MBL, ficolin-2 and ficolin-3 plasma concentrations were determined in two consecutive cohorts comprising 190 patients from Hungary and 183 patients from Norway as well as controls. Disease severity and clinical parameters were determined at baseline, and all-cause mortality was registered after 5-years follow-up. In univariate analysis a low level of ficolin-3, but not that of MBL or ficolin-2, was significantly associated with advanced heart failure (New York Heart Association Class IV, p<0.001 for both cohorts) and showed inverse correlation with B- type natriuretic peptide (BNP) levels (r = -0.609, p<0.001 and r = -0.467, p<0.001, respectively). In multivariable Cox regression analysis, adjusted for age, gender and BNP, decreased plasma ficolin-3 was a significant predictor of mortality (HR 1.368, 95% CI 1.052-6.210; and HR 1.426, 95% CI 1.013-2.008, respectively). Low ficolin-3 levels were associated with increased complement activation product C3a and correspondingly decreased concentrations of complement factor C3. CONCLUSIONS: This study provides evidence for an association of low ficolin-3 levels with advanced heart failure. Concordant results from two cohorts show that low levels of ficolin-3 are associated with advanced heart failure and outcome. The decrease of ficolin-3 was associated with increased complement activation.

Lumican is increased in experimental and clinical heart failure, and its production by cardiac fibroblasts is induced by mechanical and proinflammatory stimuli.

During progression to heart failure (HF), myocardial extracellular matrix (ECM) alterations and tissue inflammation are central. Lumican is an ECM-localized proteoglycan associated with inflammatory conditions and known to bind collagens. We hypothesized that lumican plays a role in the dynamic alterations in cardiac ECM during development of HF. Thus, we examined left ventricular cardiac lumican in a mouse model of pressure overload and in HF patients, and investigated expression, regulation and effects of increased lumican in cardiac fibroblasts. After 4 weeks of aortic banding, mice were divided into groups of hypertrophy (AB) and HF (ABHF) based on lung weight and left atrial diameter. Sham-operated mice were used as controls. Accordingly, cardiac lumican mRNA and protein levels were increased in mice with ABHF. Similarly, cardiac biopsies from patients with end-stage HF revealed increased lumican mRNA and protein levels compared with control hearts. In vitro, mechanical stretch and the proinflammatory cytokine interleukin-1ß increased lumican mRNA as well as secreted lumican protein from cardiac fibroblasts. Stimulation with recombinant glycosylated lumican increased collagen type I alpha 2, lysyl oxidase and transforming growth factor-ß1 mRNA, which was attenuated by costimulation with an inhibitor of the proinflammatory transcription factor NFκB. Furthermore, lumican increased the levels of the dimeric form of collagen type I, decreased the activity of the collagen-degrading enzyme matrix metalloproteinase-9 and increased the phosphorylation of fibrosis-inducing SMAD3. In conclusion, cardiac lumican is increased in experimental and clinical HF. Inflammation and mechanical stimuli induce lumican production by cardiac fibroblasts and increased lumican altered molecules important for cardiac remodeling and fibrosis in cardiac fibroblasts, indicating a role in HF development.

Innate immune signaling induces expression and shedding of the heparan sulfate proteoglycan syndecan-4 in cardiac fibroblasts and myocytes, affecting inflammation in the pressure-overloaded heart.

Sustained pressure overload induces heart failure, the main cause of mortality in the Western world. Increased understanding of the underlying molecular mechanisms is essential to improve heart failure treatment. Despite important functions in other tissues, cardiac proteoglycans have received little attention. Syndecan-4, a transmembrane heparan sulfate proteoglycan, is essential for pathological remodeling, and we here investigated its expression and shedding during heart failure. Pressure overload induced by aortic banding for 24 h and 1 week in mice increased syndecan-4 mRNA, which correlated with mRNA of inflammatory cytokines. In cardiac myocytes and fibroblasts, tumor necrosis factor-α, interleukin-1ß and lipopolysaccharide through the toll-like receptor-4, induced syndecan-4 mRNA. Bioinformatical and mutational analyses in HEK293 cells identified a functional site for the proinflammatory nuclear factor-κB transcription factor in the syndecan-4 promoter, and nuclear factor-κB regulated syndecan-4 mRNA in cardiac cells. Interestingly, tumor necrosis factor-α, interleukin-1ß and lipopolysaccharide induced nuclear factor-κB-dependent shedding of the syndecan-4 ectodomain from cardiac cells. Overexpression of syndecan-4 with mutated enzyme-interacting domains suggested enzyme-dependent heparan sulfate chains to regulate shedding. In cardiac fibroblasts, lipopolysaccharide reduced focal adhesion assembly, shown by immunohistochemistry, suggesting that inflammation-induced shedding affects function. After aortic banding, a time-dependent cardiac recruitment of T lymphocytes was observed by measuring CD3, CD4 and CD8 mRNA, which was reduced in syndecan-4 knockout hearts. Finally, syndecan-4 mRNA and shedding were upregulated in failing human hearts. Conclusively, our data suggest that syndecan-4 plays an important role in the immune response of the heart to increased pressure, influencing cardiac remodeling and failure progression.

Disturbed carnitine regulation in chronic heart failure--increased plasma levels of palmitoyl-carnitine are associated with poor prognosis.

BACKGROUND/OBJECTIVES: Heart failure is characterized by disturbed energy metabolism and impaired mitochondrial function. L-carnitine plays a critical role in fatty acid transport into the mitochondria and may thus influence inflammation and myocardial function. The aim of this study was to investigate carnitine metabolism in relation to progression of heart failure (HF). METHODS AND RESULTS: We examined plasma levels of free L-carnitine as well as several of its precursors and derivates in HF patients (n=183) and matched healthy controls (n=111) as well as their relationship with cardiac dysfunction as assessed by echocardiographic measurements, inflammation (CRP) and neurohormonal activation (NT-proBNP) in addition to the prognostic value of carnitine derivates in relation to mortality in these patients. High levels of the carnitine derivates acetyl-carnitine and in particular palmitoyl-carnitine were associated with the degree of HF as evaluated by clinical (NYHA functional class) and neurohormonal assessments. Moreover, plasma levels of palmitoyl-carnitine were associated with serious adverse events (i.e., all-cause mortality and heart transplantation) during follow-up, independently of more established risk markers such as CRP and NT-proBNP, when analyzed by cox-regression and continous net reclassification improvement, but not c-statistics. CONCLUSIONS: Our findings support a role for disturbed carnitine metabolism in the pathogenesis of HF, and suggest that some of its derivates could give prognostic information in these patients.

Intravenous immunoglobulin does not reduce left ventricular remodeling in patients with myocardial dysfunction during hospitalization after acute myocardial infarction.

BACKGROUND: Left ventricular (LV) remodeling takes place after acute myocardial infarction (MI), potentially leading to overt heart failure (HF). Enhanced inflammation may contribute to LV remodeling. Our hypothesis was that the immunomodulating effects of intravenous immunoglobulin (IVIg) would be beneficial in patients with impaired myocardial function after MI by reducing myocardial remodeling and improving myocardial function. METHODS: Sixty-two patients with acute MI treated by percutaneous coronary intervention, with depressed LV ejection fraction (LVEF) were randomized in a double-blinded fashion to IVIg as induction therapy and thereafter as monthly infusions or placebo for 26 weeks. The primary end point was changes in LVEF from baseline to 6 months as assessed by MRI. RESULTS: Our main findings were: (i) LVEF increased significantly from 38 ± 10 (mean ± SD) to 45 ± 13% after IVIg and from 42 ± 9 to 49 ± 12% after placebo with no difference between the groups. (ii) The scar area decreased significantly by 3% and 5% in the IVIg and placebo group, respectively, with no difference between the groups. (iii) During the induction therapy (baseline to day 5), IVIg induced both inflammatory (e.g., increase in tumor necrosis factor α and monocyte chemoattractant protein-1) and anti-inflammatory (e.g., increase in interleukin-10 and decrease in leukocyte counts) variables, but during maintenance therapy there were no differences in changes of inflammatory mediators between IVIg and placebo. CONCLUSIONS: IVIg therapy after ST elevation MI managed by primary PCI does not affect LV remodeling or function. This illustrates the challenges of therapeutic intervention directed against the cytokine network, to prevent post-MI remodeling.