Serum syndecan-4 is a novel biomarker for patients with chronic heart failure

Novel cardiac extracellular matrix biomarkers in STEMI: Associations with ischemic injury and long-term mortality

BACKGROUND

We aimed to determine whether serum levels of proteins related to changes in cardiac extracellular matrix (ECM) were associated with ischemic injury assessed by cardiac magnetic resonance (CMR) and mortality in patients with ST-elevation myocardial infarction (STEMI).

METHODS

The concentrations of six ECM-related proteins (periostin, osteopontin, syndecan-1, syndecan-4, bone morphogenetic protein 7, and growth differentiation factor (GDF)-15) were measured in serum samples from patients on Day 1 and Month 4 after STEMI (n = 239). Ischemic injury was assessed by myocardial salvage index, microvascular obstruction, infarct size, and left ventricular function measured by CMR conducted during the initial admission (median 2 days after admission) and after 4 months. All-cause mortality was recorded after a median follow-up time of 70 months.

RESULTS

Levels of periostin increased from Day 1 to Month 4 after hospitalization, while the levels of GDF-15, osteopontin, syndecan-1, and syndecan-4 declined. At both time points, high levels of syndecan-1 were associated with microvascular obstruction, large infarct size, and reduced left ventricular ejection fraction, whereas high levels of syndecan-4 at Month 4 were associated with a higher myocardial salvage index and less dilatation of the left ventricle. Higher mortality rates were associated with periostin levels at both time points, low syndecan-4 levels at Month 4, or high GDF-15 levels at Month 4.

CONCLUSIONS

In patients with STEMI, we found an association between serum levels of ECM biomarkers and ischemic injury and mortality. The results provide new insight into the role ECM components play in ischemic injury following STEMI and suggests a potential for these biomarkers in prognostication after STEMI.

Inflammation and Syndecan-4 Shedding from Cardiac Cells in Ischemic and Non-Ischemic Heart Disease

Circulating biomarkers reflecting cardiac inflammation are needed to improve the diagnostics and guide the treatment of heart failure patients. The cardiac production and shedding of the transmembrane proteoglycan syndecan-4 is upregulated by innate immunity signaling pathways. Here, we investigated the potential of syndecan-4 as a blood biomarker of cardiac inflammation. Serum syndecan-4 was measured in patients with (i) non-ischemic, non-valvular dilated cardiomyopathy (DCM), with (n = 71) or without (n = 318) chronic inflammation; (ii) acute myocarditis (n = 15), acute pericarditis (n = 3) or acute perimyocarditis (23) and (iii) acute myocardial infarction (MI) at day 0, 3 and 30 (n = 119). Syndecan-4 was investigated in cultured cardiac myocytes and fibroblasts (n = 6–12) treated with the pro-inflammatory cytokines interleukin (IL)-1β and its inhibitor IL-1 receptor antagonist (IL-1Ra), or tumor necrosis factor (TNF)α and its specific inhibitor infliximab, an antibody used in treatment of autoimmune diseases. The levels of serum syndecan-4 were comparable in all subgroups of patients with chronic or acute cardiomyopathy, independent of inflammation. Post-MI, syndecan-4 levels were increased at day 3 and 30 vs. day 0. IL-1Ra attenuated IL-1β-induced syndecan-4 production and shedding in vitro, while infliximab had no effect. In conclusion, syndecan-4 shedding from cardiac myocytes and fibroblasts was attenuated by immunomodulatory therapy. Although its circulating levels were increased post-MI, syndecan-4 did not reflect cardiac inflammatory status in patients with heart disease.

Cardiomyocyte-specific overexpression of syndecan-4 in mice results in activation of calcineurin-NFAT signalling and exacerbated cardiac hypertrophy

BACKGROUND

Cardiomyocyte hypertrophy is a hallmark of cardiac dysfunction in patients with aortic stenosis (AS), and can be triggered by left ventricular (LV) pressure overload in mice by aortic banding (AB). Syndecan-4 is a transmembrane heparan sulphate proteoglycan which is found increased in the myocardium of AS patients and AB mice. The role of syndecan-4 in cardiomyocyte hypertrophy is not well understood.

PURPOSE OF THE STUDY

We developed mice with cardiomyocyte-specific overexpression of syndecan-4 (Sdc4-Tg) and subjected these to AB to examine the role of syndecan-4 in hypertrophy and activation of the pro-hypertrophic calcineurin-NFAT signalling pathway.

METHODS AND RESULTS

Sdc4-Tg mice showed exacerbated cardiac remodelling upon AB compared to wild type (WT). At 2-6 weeks post-AB, Sdc4-Tg and WT mice showed similar hypertrophic growth, while at 20 weeks post-AB, exacerbated hypertrophy and dysfunction were evident in Sdc4-Tg mice. After cross-breeding of Sdc4-Tg mice with NFAT-luciferase reporter mice, we found increased NFAT activation in Sdc4-Tg hearts after AB. Immunoprecipitation showed that calcineurin bound to syndecan-4 in Sdc4-Tg hearts. Isolated cardiomyocytes from Sdc4-Tg mice showed alterations in Ca2+ fluxes, suggesting that syndecan-4 regulated Ca2+ levels, and thereby, activating the syndecan-4-calcineurin complex resulting in NFAT activation and hypertrophic growth. Similarly, primary cardiomyocyte cultures from neonatal rats showed increased calcineurin-NFAT-dependent hypertrophic growth upon viral Sdc4 overexpression.

CONCLUSION

Our study of mice with cardiomyocyte-specific overexpression of Sdc4 have revealed that syndecan-4 is important for activation of the Ca2+-dependent calcineurin-NFAT signalling pathway, hypertrophic remodelling and dysfunction in cardiomyocytes in response to pressure overload.

Serum syndecan-4 correlates with blood pressure and cardiovascular parameters but not proinflammatory markers in healthy older women

Aging is accompanied by a low-grade proinflammatory status that plays a role in age-related vascular alterations. Syndecan-4 (SDC4) is a key component of the endothelial glycocalyx, and its extracellular domain can be shed by matrix metalloproteinase-9 (MMP-9). In vitro studies demonstrated that MMP-9-mediated shedding of SDC4 is induced by tumor necrosis factor-α (TNF- α) in human endothelial cells. However, the relationship between circulating shed SDC4, systemic inflammation, and age-related vascular alterations remains unknown. Here, we used linear regression models to examine the associations of serum SDC4 levels with cardiovascular hemodynamic phenotypes, serum MMP-9, and serum TNF-α and inteleukin-6 in healthy older women (n = 74). Serum SDC4 was not associated with proinflammatory cytokines or arterial elasticity. Nevertheless, we found significant correlations of SDC4 with MMP-9, heart rate, left ventricular ejection time, systemic vascular resistance, and blood pressure. Our preliminary evidence suggests that systemic inflammation might not induce SDC4 shedding in healthy aging.

The role of the glypican and syndecan families of heparan sulfate proteoglycans in cardiovascular function and disease

Heparan sulfate proteoglycans (HSPGs) are proteoglycans formed by a core protein to which one or multiple heparan sulfate chains are covalently bound. They are ubiquitously expressed in cellular surfaces and can be found in the extracellular matrix and secretory vesicles. The cellular effects of HSPGs comprehend multiple functionalities that include 1) the interaction with other membrane surface proteins to act as a substrate for cellular migration, 2) acting as a binding site for circulating molecules, 3) to have a receptor role for proteases, 4) to act as a coreceptor that can provide finetuning of growth factor receptor activity threshold, and 5) to activate intracellular signaling pathways (Sarrazin S, Lamanna WC, Esko JD. Cold Spring Harb Perspect Biol 3: a004952, 2011). Among the different families of HSPGs, the syndecan and glypican families of HSPGs have gained increased attention in relation to their effects on cardiovascular cells and potential role in disease progression. In this review, we will summarize the effects of syndecan and glypican homologs on the different cardiovascular cell types and discuss their contribution to common processes found in cardiovascular diseases (inflammation, hypertrophy, and vascular remodeling) as well as their potential role in the development and progression of specific diseases including hypertension, heart failure, and atherosclerosis.

Biomarkers of Myocardial Injury and Remodeling in Heart Failure

With its complicated pathophysiology, high incidence and prevalence, heart failure remains a major public concern. In hopes of improving diagnosis, treatment and prognosis, the utility of many different biomarkers is researched vigorously around the world. In this review, biomarkers of myocardial remodeling and fibrosis (galectin-3, soluble isoform of suppression of tumorigenicity 2, matrix metalloproteinases, osteopontin, interleukin-6, syndecan-4, myostatin, procollagen type I C-terminal propeptide, procollagen type III N-terminal propeptide, vascular endothelial growth factor, nitric oxidase synthetase and asymmetric dimethylarginine), myocyte injury (heart-type fatty acid-binding protein, glutathione S-transferase P1 and heat shock protein 60), as well as iron metabolism (ferritin, transferrin saturation, soluble transferrin receptor and hepcidin), are considered in terms of possible clinical applicability and significance. Our short review consists of a summary of the aforementioned cardiovascular biomarkers' clinical relevance and perspectives.

Shexiang Tongxin Dropping Pill Protects Against Chronic Heart Failure in Mice via Inhibiting the ERK/MAPK and TGF-β Signaling Pathways

Background: Chronic heart failure (CHF) is a major public health problem with high mortality and morbidity worldwide. Shexiang Tongxin Dropping Pill (STDP) is a widely used traditional Chinese medicine preparation for coronary heart disease and growing evidence proves that STDP exerts beneficial effects on CHF in the clinic. However, the molecular mechanism of the therapeutic effects of STDP on CHF remains largely unknown.

Objective: This study aimed to elucidate the mechanism of action of STDP against CHF by integrating network pharmacology analysis and whole-transcriptome sequencing.

Methods: First, the mouse model of CHF was established by the transverse aortic constriction (TAC) surgery, and the efficacy of STDP against CHF was evaluated by assessing the alterations in cardiac function, myocardial fibrosis, and cardiomyocyte hypertrophy with echocardiography, Masson’s trichrome staining, and wheat germ agglutinin staining. Next, a CHF disease network was constructed by integrating cardiovascular disease-related genes and the transcriptome sequencing data, which was used to explore the underlying mechanism of action of STDP. Then, the key targets involved in the effects of STDP on CHF were determined by network analysis algorithms, and pathway enrichment analysis was performed to these key genes. Finally, important targets in critical pathway were verified in vivo.

Results: STDP administration obviously improved cardiac function, relieved cardiomyocyte hypertrophy, and ameliorated myocardial fibrosis in CHF mice. Moreover, STDP significantly reversed the imbalanced genes that belong to the disease network of CHF in mice with TAC, and the number of genes with the reverse effect was 395. Pathway analysis of the crucial genes with recovery efficiency revealed that pathways related to fibrosis and energy metabolism were highly enriched, while TGF-β pathway and ERK/MAPK pathway were predicted to be significantly affected. Consistently, validation experiments confirmed that inhibiting ERK/MAPK and TGF-β signaling pathways via reduction of the phosphorylation level of Smad3 and ERK1/2 is the important mechanism of STDP against CHF.

Conclusion: Our data demonstrated that STDP can recover the imbalanced CHF network disturbed by the modeling of TAC through the multi-target and multi-pathway manner in mice, and the mechanisms are mainly related to inhibition of ERK/MAPK and TGF-β signaling pathways.

[Change of serum levels of pentraxin-3 and syndecan-4 in children with chronic heart failure]

OBJECTIVE

To study the change and significance of serum pentraxin-3 (PTX-3) and syndecan-4 in children with chronic heart failure (CHF).

METHODS

A total of 40 children with CHF who were admitted to the Department of Pediatrics of the First Affiliated Hospital of Zhengzhou University were enrolled as the heart failure group, and 30 children who underwent physical examination in the outpatient service during the same period of time were enrolled as the control group. The serum levels of PTX-3, syndecan-4, and N-terminal pro-brain natriuretic peptide (NT-proBNP) were compared between the two groups.

RESULTS

The children with CHF had significant reductions in the serum levels of PTX-3, syndecan-4, and NT-proBNP after treatment. The levels of these markers in children with CHF were significantly higher than the control group before and after treatment (P < 0.05). The CHF children with grade II/III/IV cardiac function had significantly higher serum levels of PTX-3 and syndecan-4 than the control group (P < 0.05). The levels of PTX-3 and syndecan-4 were related to the severity of cardiac function. Compared with the grade II cardiac function group, the grade IV cardiac function group had significant increases in the serum levels of PTX-3 and syndecan-4 (P < 0.05). The serum level of PTX-3 was positively correlated with that of syndecan-4 in children with CHF (r_s=0.999, P < 0.05); the serum level of PTX-3 was positively correlated with NT-proBNP, left ventricular mass index (LVMI), and cardiac function grade (r_s=0.726, 0.736, and 0.934 respectively, P < 0.05) and was negatively correlated with left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) (r_s=-0.852 and -0.767 respectively, P < 0.05); the serum level of syndecan-4 was positively correlated with NT-proBNP, LVMI, and cardiac function grade (r_s=0.733, 0.743, and 0.934 respectively, P < 0.05) and was negatively correlated with LVEF and LVFS (r_s=-0.856 and -0.771 respectively, P < 0.05).

CONCLUSIONS

Serum PTX-3 and syndecan-4 may be involved in the development and progression of ventricular remodeling in children with CHF and may be used as markers for the diagnosis, cardiac function grading, and treatment outcome evaluation of children with heart failure.

Syndecan-4 as a Marker of Endothelial Dysfunction in Patients with Resistant Hypertension

(1) Background: Arterial hypertension (HTN) is one of the most relevant cardiovascular risk factors. Nowadays multiple pharmaceutical treatment options exist with novel interventional methods (e.g., baroreflex activation therapy (BAT)) as a last resort to treat patients with resistant HTN. Although pathophysiology behind resistant HTN is still not fully understood. There is evidence that selected biomarkers may be involved in the pathophysiology of HTN. (2) Methods: We investigated serum SDC4-levels in patients suffering from resistant HTN before and 6 months after BAT implantation. We collected 19 blood samples from patients with resistant HTN and blood pressure above target and measured serum SDC4-levels. (3) Results: Our results showed high serum SDC4-levels in patients with resistant HTN as compared to a healthy population. Patients with both, resistant HTN and diabetes mellitus type II, demonstrated higher serum SDC4-levels. β-blockers had lowering effects on serum SDC4-levels, whereas calcium channel blockers were associated with higher levels of serum SDC4. BAT implantation did not lead to a significant difference in serum SDC4-levels after 6 months of therapy. (4) Conclusion: Based on our results we propose SDC4 is elevated in patients suffering from resistant HTN. Thus, SDC4 might be a potential marker for endothelial dysfunction in patients with resistant hypertension.

Serum Matrix Metalloproteinases and Left Atrial Remodeling-The Hoorn Study

Extracellular matrix protein turnover may play an important role in left atrial (LA) remodelling. The aim is to investigate the associations between matrix metalloproteinase (MMPs), tissue inhibitor of metalloproteinase (TIMP-1) and LA volume index (LAVI) and if these associations are independent of TIMP-1 levels. Participants from The Hoorn Study, a population-based cohort study (n = 674), underwent echocardiography. Serum MMPs (i.e., MMP-1, MMP-2, MMP-3, MMP-9, and MMP-10) and TIMP-1 levels were measured with ELISA. Multiple linear regression analyses were used. MMP-1 levels were not associated with LAVI. Higher MMP-2 levels were associated with larger LAVI (regression coefficient per SD increase in MMP (95% CI); 0.03 (0.01; 0.05). Higher MMP-3 and MMP-9 levels were associated with smaller LAVI; −0.04 (−0.07; −0.01) and −0.04 (−0.06; −0.02) respectively. Only in women were higher MMP-10 levels associated with larger LAVI; 0.04 (0.00; 0.07, p-interaction 0.04). Additionally, only in women were higher TIMP-1 levels associated with smaller LAVI; −0.05 (−0.09; −0.01, p-interaction 0.03). The associations between MMPs and LAVI were independent of TIMP-1 levels. In conclusion, serum MMPs are associated with LAVI, independent of CVD risk factors and TIMP-1 levels. In addition, these associations differ according to sex and within MMP subgroups. This shows that the role of MMPs in LA remodelling is complex.

Syndecan-4 Protects the Heart From the Profibrotic Effects of Thrombin-Cleaved Osteopontin

Background Pressure overload of the heart occurs in patients with hypertension or valvular stenosis and induces cardiac fibrosis because of excessive production of extracellular matrix by activated cardiac fibroblasts. This initially provides essential mechanical support to the heart, but eventually compromises function. Osteopontin is associated with fibrosis; however, the underlying signaling mechanisms are not well understood. Herein, we examine the effect of thrombin-cleaved osteopontin on fibrosis in the heart and explore the role of syndecan-4 in regulating cleavage of osteopontin. Methods and Results Osteopontin was upregulated and cleaved by thrombin in the pressure-overloaded heart of mice subjected to aortic banding. Cleaved osteopontin was higher in plasma from patients with aortic stenosis receiving crystalloid compared with blood cardioplegia, likely because of less heparin-induced inhibition of thrombin. Cleaved osteopontin and the specific osteopontin peptide sequence RGDSLAYGLR that is exposed after thrombin cleavage both induced collagen production in cardiac fibroblasts. Like osteopontin, the heparan sulfate proteoglycan syndecan-4 was upregulated after aortic banding. Consistent with a heparan sulfate binding domain in the osteopontin cleavage site, syndecan-4 was found to bind to osteopontin in left ventricles and cardiac fibroblasts and protected osteopontin from cleavage by thrombin. Shedding of the extracellular part of syndecan-4 was more prominent at later remodeling phases, at which time levels of cleaved osteopontin were increased. Conclusions Thrombin-cleaved osteopontin induces collagen production by cardiac fibroblasts. Syndecan-4 protects osteopontin from cleavage by thrombin, but this protection is lost when syndecan-4 is shed in later phases of remodeling, contributing to progression of cardiac fibrosis.

Role of matrix metalloproteinases and histone deacetylase in oxidative stress-induced degradation of the endothelial glycocalyx

The glycocalyx is crucial for normal endothelial function. It also tethers extracellular superoxide dismutase (SOD3), which protects the endothelium against oxidative damage. Proteolytic enzymes [matrix metalloproteinases (MMPs)] are capable of disrupting endothelial cell surface proteins, such as syndecans, resulting in derangements of the endothelial glycocalyx. We sought to test the role of MMPs in oxidative stress-mediated disruption of the endothelial glycocalyx and examine the effect of pharmacological inhibition of MMPs on mitigating this detrimental effect. We also examined the role of histone deacetylase (HDAC) in the oxidative stress-mediated MMP induction and glycocalyx remodeling. Oxidative stress was experimentally induced in human adipose microvascular endothelial cells using H₂O₂ and buthionine sulfoximine in the presence and absence of potent MMP and HDAC inhibitors. H₂O₂ and buthionine sulfoximine resulted in a notable loss of the endothelial glycocalyx; they also increased the expression and proteolytic activity of MMP-2 and MMP-9 and subsequently increased the shedding of syndecan-1 and SOD3 from the endothelial cell surface. MMP upregulation was accompanied by a decline in mRNA and protein levels of their inhibitors, tissue inhibitors of metalloproteinase (TIMPs; TIMP-1 and TIMP-3). Furthermore, oxidative stress induced HDAC activity. Inhibition of MMPs and HDAC reversed syndecan-1 and SOD3 shedding and maintained endothelial glycocalyx integrity. HDAC inhibition increased TIMP expression and reduced MMP expression and activity in endothelial cells. Our findings shed light on MMPs and HDAC as therapeutically targetable mechanisms in oxidative stress-induced glycocalyx remodeling. NEW & NOTEWORTHY Oxidative stress, a hallmark of many diseases, damages the endothelial glycocalyx, resulting in vascular dysfunction. Studying the mechanistic link between oxidative stress and endothelial glycocalyx derangements might help discover new therapeutic targets to preserve vascular function. In this study, we investigated the involvement of matrix metalloproteinases and histone deacetylase in oxidative stress-induced endothelial glycocalyx degradation.

Assessment of syndecan-4 expression in the hearts of Trypanosoma cruzi-infected mice and human subjects with chronic Chagas disease cardiomyopathy

Background

Chronic Chagas cardiomyopathy (CCC) is characterized by the presence of a multifocal inflammatory response and myocardial damage, leading to fibrosis, arrhythmias and ventricular dysfunction. The expression of syndecan-4, a transmembrane proteoglycan, was previously found to be increased in the hearts of mice chronically infected with Trypanosoma cruzi. The possible involvement of syndecan-4 in the disease pathogenesis, however, remains unknown. Here we evaluated the pattern of expression of syndecan-4 in the heart tissue of T. cruzi infected mice and subjects with Chagas cardiomyopathy, correlating with the degree of inflammation and fibrosis.

Methods

The expression of syndecan-4 was evaluated by immunofluorescence and RT-qPCR in the hearts of C57Bl/6 mice at different time points after infection with the Colombian strain of T. cruzi. Immunostainings for syndecan-4 were performed in heart samples obtained from CCC patients and other etiologies of heart failure. The number of infiltrating inflammatory cells and area of fibrosis were also evaluated and quantified.

Results

In the experimental model, the number of infiltrating inflammatory cells and fibrosis area in the hearts progressively increased after the acute phase of infection, while syndecan-4 expression remained elevated in similar levels in both the acute and chronic phases. Confocal microscopy analysis demonstrated the localization of syndecan-4 expression in blood vessels, co-localized with α-SMA, a marker for vascular smooth muscle cells (VSMCs). Confocal microscopy analysis of human hearts samples showed a similar pattern of syndecan-4 expression in blood vessels. No correlation between syndecan-4 expression and inflammation or fibrosis was found in the hearts from subjects with CCC. We also compared the expression of syndecan-4 evaluated in subjects with CCC, idiopathic dilated cardiomyopathy and ischemic cardiomyopathy. No differences in the number of syndecan-4 positive vessels/mm2 were found comparing the three groups (P = 0.466), whereas CCC patients presented a higher number of infiltrating inflammatory cells, compared to the other etiologies of heart failure. Additionally, no correlation between syndecan-4 and fibrosis or numbers of inflammatory cells was found.

Conclusions

Syndecan-4 is expressed in the heart during the acute and chronic phases of Chagas disease, in association with VSMCs, independently of the degree of myocardial fibrosis or the number of infiltrating inflammatory cells.

Systems Genetics Approach to Biomarker Discovery: GPNMB and Heart Failure in Mice and Humans

We describe a simple bioinformatics method for biomarker discovery that is based on the analysis of global transcript levels in a population of inbred mouse strains showing variation for disease-related traits. This method has advantages such as controlled environment and accessibility to heart and plasma tissue in the preclinical selection stage. We illustrate the approach by identifying candidate heart failure (HF) biomarkers by overlaying mouse transcriptome and clinical traits from 91 Hybrid Mouse Diversity Panel (HMDP) inbred strains and human HF transcriptome from the Myocardial Applied Genomics Network (MAGNet) consortium. We found that some of the top differentially expressed genes correlated with known human HF biomarkers, such as galectin-3 and tissue inhibitor of metalloproteinase 1. Using ELISA assays, we investigated one novel candidate, Glycoprotein NMB, in a mouse model of chronic β-adrenergic stimulation by isoproterenol (ISO) induced HF. We observed significantly lower GPNMB plasma levels in the ISO model compared to the control group (p-value = 0.007). In addition, we assessed GPNMB plasma levels among 389 HF cases and controls from the METabolic Syndrome In Men (METSIM) study. Lower levels of GPNMB were also observed in patients with HF from the METSIM study compared to non-HF controls (p-value < 0.0001). In summary, we have identified several candidate biomarkers for HF using the cardiac transcriptome data in a population of mice that may be directly relevant and applicable to human populations.

Soluble syndecans: biomarkers for diseases and therapeutic options

Syndecans are important mediators of signalling by transmitting external stimuli into the cells. This role in signal transduction has been attributed mainly to the membrane-bound syndecans. In the last years, however, the soluble ectodomain of syndecans generated by shedding has come into the focus of research as this process has been show to modulate the syndecan-dependent signalling pathways, as well as other pathways. This review summarizes the current knowledge about the induction of syndecan shedding and the different pathways modulated by shed syndecan proteins. This review summarizes the known and putative sheddases for each syndecan and describes the exemplary conditions of sheddase activity for some syndecans. This review summarizes the proposed use of shed syndecans as biomarkers for various diseases, as the shedding process of syndecans depends crucially on tissue- and disease-specific activation of the sheddases. Furthermore, the potential use of soluble syndecans as a therapeutic option is discussed, on the basis of the current literature. LINKED ARTICLES: This article is part of a themed section on Translating the Matrix. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.1/issuetoc.

Lack of association between serum syndecan-4, myocardial fibrosis and ventricular dysfunction in subjects with chronic Chagas disease

BACKGROUND

Syndecan-4 is a transmembrane glycoprotein associated with inflammation and fibrosis. Increased syndecan-4 levels were previously detected after acute myocardial infarction and in subjects with heart failure. However, the levels of syndecan-4 in subjects with Chagas disease have not so far been investigated. The aim of this study was to investigate the potential role of serum sydencan-4 as a novel biomarker for myocardial fibrosis and cardiac dysfunction in subjects with Chagas disease.

METHODS

This study comprised subjects with Chagas disease (n = 56), being 14 (25%) with the indeterminate form, 16 (29%) with the cardiac form without ventricular dysfunction, and 26 (46%) with the cardiac form with ventricular dysfunction.

RESULTS

Syndecan-4 serum concentrations did not correlate with presence or absence of myocardial fibrosis (P = 0.386) nor disease severity in subjects with Chagas disease (P = 0.918). Additionally, no correlation was found either between the degree of myocardial fibrosis and serum syndecan-4 [r = 0.08; P = 0.567] or between left ventricular ejection fraction and syndecan-4 [r = 0.02; P = 0.864]. In contrast, NT-proBNP levels correlated with ejection fraction and myocardial fibrosis.

CONCLUSIONS

Our results demonstrate the lack of correlations between serum syndecan-4, myocardial fibrosis and cardiac dysfunction in subjects with Chagas disease. Further studies are required to show if syndecan-4 concentrations can be marker for prognosis assessment or disease progression.

Syndecan-4 Is an Independent Predictor of All-Cause as Well as Cardiovascular Mortality in Hemodialysis Patients

Background

Left ventricular hypertrophy is associated withincreased mortality in hemodialysis (HD) patients.Syndecan-4 plays a role in many processes that are involved in the heart fibrosis and hypertrophy.We designed this study to prospectively determine whether syndecan-4 was predictive of mortality in a group of HD patients.

Methods

In total, 191 HD patients were included. Clinical, biochemical and echocardiographic parameters were recorded. HD patients were followed-up for 23.18 ± 4.02 months.

Results

Syndecan-4 levels correlated strongly with geometrical echocardiographic parameters and ejection fraction. Relations with pressure-related parameters were weak and only marginally significant. Using the receiver operating characteristics the optimal cut-off points in predicting all-cause as well as cardiovascular (CV) mortality were evaluated and patients were divided into low and high syndecan-4 groups. A Kaplan–Meier analysis showed that the cumulative incidences of all-cause as well as CV mortality were higher in high serum syndecan-4 group compared with those with low serum syndecan-4 (p<0.001 in both cases).A multivariate Cox proportional hazards regression analysis revealed syndecan-4 concentration to be an independent and significant predictor of all-cause (hazard ratio, 2.99; confidence interval, 2.34 to 3.113; p<0.001)as well as CV mortality (hazard ratio, 2.81;confidence interval, 2.28to3.02; p<0.001).

Conclusions

Serum syndecan-4 concentration reflects predominantly geometrical echocardiographic parameters. In HD patients serum syndecan-4 concentration is independently associated with all-cause as well as CV mortality.

Differences in biochemical and genetic biomarkers in patients with heart failure of various etiologies

BACKGROUND/OBJECTIVES

To evaluate whether biomarkers reflecting pathophysiological pathways and selected single nucleotide polymorphisms differ between patients (pts) with heart failure (HF).

METHODS

110 pts with were involved, including HF pts with preserved ejection fraction (HFpEF, n=51) with hypertensive origin, HF pts with reduced ejection fraction (HFrEF) with ischemic aetiology (ICM) (n=32) and HFrEF with dilated cardiomyopathy (DCM) (n=27). We assessed selected HF biomarkers, echocardiographic examinations and functional polymorphisms selected from six candidate genes: CYP27B1, NOS3, IL-6, TGF beta, TNF alpha, and PPAR gamma.

RESULTS

Higher concentrations of TNF alpha were observed in pts with hypertensive HFpEF compared to pts with DCM (p=0.008). Pts with HFpEF had higher concentrations of TGF beta 1 compared to DCM and ICM (p=0.0001 and p=0.0003, respectively). For the NOS3 -786 C/T rs2070744 polymorphism in DCM there were significantly more CT heterozygotes than in ICM and HFpEF. In multivariate analysis TGF beta 1 (p=0.001) and syndecan 4 (p=0.001) were the only factors distinguishing HFrEF pts with DCM vs HFpEF and also TGF beta 1 (p=0.001) and syndecan 4 (p=0.023) were the only factors distinguishing HFrEF pts with ICM vs HFpEF pts.

CONCLUSIONS

Inflammation mediated through TNF alpha and TGF beta 1 may represent an important component of an inflammatory response that partially drives the pathophysiology of HFpEF. NOS3 -786 C/T rs2070744 polymorphism in DCM may serve as a marker for more rapid progression of heart failure. The only biomarkers independently distinguishing HFpEF and HFrEF are syndecan 4 and TGF beta 1.

Syndecan-4 shedding impairs macrovascular angiogenesis in diabetes mellitus

PURPOSE

Syndecan-4 (synd4) is a ubiquitous heparan sulfate proteoglycan cell surface receptor that modulates cell proliferation, migration, mechanotransduction, and endocytosis. The extracellular domain of synd4 sheds heavily in acute inflammation, but the shedding of synd4 in chronic inflammation, such as diabetes mellitus (DM), is still undefined. We investigated the alterations of synd4 endothelial expression in DM and the influence of impaired synd4 signaling on angiogenesis in human umbilical vein endothelial cells (HUVECs), diabetic rats, synd4 null mice, and db/db mice.

MATERIAL AND METHODS

HUVECs were incubated with advanced glycation end products (AGEs). Western blot analysis was used to determine synd4 protein expression and ELISA was used to detect soluble synd4 fragments. The concentration of synd4 in the aortic endothelia of diabetic rats was detected by immunohistochemical staining. Aortic ring assays were performed to study the process of angiogenesis in the diabetic rats and in synd4 null and db/db mice. Recombinant adenoviruses containing the synd4 gene or null were constructed to enhance synd4 aortic expression in db/db mice.

RESULTS

Western blot analysis showed decreased expression of the synd4 extracellular domain in HUVECs, and ELISA detected increased soluble fragments of synd4 in the media. Synd4 endothelial expression in the aortas of diabetic rats was decreased. Aortic ring assay indicated impaired angiogenesis in synd4 null and db/db mice, which was partially reversed by synd4 overexpression in db/db mice.

CONCLUSION

Synd4 shedding from vascular endothelial cells played an important role in the diabetes-related impairment of angiogenesis.

Syndecan-4 ectodomain evokes mobilization of podocyte TRPC6 channels and their associated pathways: An essential role for integrin signaling

PodocyteTRPC6 channels have been implicated in glomerular diseases. Syndecan-4 (Sdc4) is a membrane proteoglycan that can be cleaved to release a soluble ectodomain capable of paracrine and autocrine signaling. We have confirmed that overexpression of Sdc4 core protein increases surface abundance of TRPC6 channels in cultured podocytes, whereas Sdc4 knockdown has the opposite effect. Exposure to soluble Sdc4 ectodomain also increased the surface abundance of TRPC6, and increased cationic currents evoked by a diacylglycerol analog in podocytes. Sdc4 ectodomain increased generation of reactive oxygen species (ROS), reduced activation of RhoA, increased activation of Rac1, increased nuclear abundance of NFATc1, and increased total β3-integrin. The effects of Sdc4 ectodomain on cell-surface TRPC6 were blocked by the ROS quencher TEMPOL, and by the Rac1 inhibitor NSC-23766, but were not blocked by inhibition of calcineurin-NFATc1 signaling. The Sdc4 core protein co-immunoprecipitates with β3-integrin in cultured podocytes. Moreover, effects of Sdc4 ectodomain on TRPC6, ROS generation, Rac1 and RhoA modulation, and NFATc1 activation were blocked by cilengitide, a selective inhibitor of outside-in signaling through αv-containing integrins. Exposure to TNF, or serum from three patients with recurrent FSGS in relapse, increased shedding of podocyte Sdc4 ectodomains into the surrounding medium. This was also observed after treating podocytes with the metalloproteinase ADAM17 or after overexpression of the Sdc4 core protein. Increased concentrations of Sdc4 ectodomain were detected in urine of rats during acute puromycin aminonucleoside nephrosis. Locally generated Sdc4 may play a role in regulating TRPC6 channels, and may contribute to glomerular pathology.

Syndecan-4 is a major syndecan in primary human endothelial cells in vitro, modulated by inflammatory stimuli and involved in wound healing

Syndecans are important cell surface proteoglycans with many functions; yet, they have not been studied to a very large extent in primary human endothelial cells. The purpose of this study was to investigate syndecan-4 expression in cultured human umbilical vein endothelial cells (HUVECs) and assess its role in inflammatory reactions and experimental wound healing. qRT-PCR analysis revealed that syndecan-3 and syndecan-4 were highly expressed in HUVECs, whereas the expression of syndecan-1 and -2 was low. HUVECs were cultured with the inflammatory mediators lipopolysaccharide (LPS) and interleukin 1β (IL-1β). As a result, syndecan-4 expression showed a rapid and strong increase. Syndecan-1 and -2 expressions decreased, whereas syndecan-3 was unaffected. Knockdown of syndecan-4 using siRNA resulted in changes in cellular morphology and focal adhesion sites, delayed wound healing and tube formation, and increased secretion of the pro-inflammatory and angiogenic chemokine, CXCL8. These data suggest functions for syndecan-4 in inflammatory reactions, wound healing and angiogenesis in primary human endothelial cells.

Contribution of syndecan-4 genetic variants to hypertension, the TAMRISK study

BACKGROUND

A human syndecan-4 genetic variant (rs1981429) has previously been associated with lean tissue mass and intra-abdominal fat, and SNP rs4599 with resting energy expenditure in healthy early pubertal children. These variations could thus cause overweight and hypothetically lead to hypertension. Their association with body mass index and blood pressure was therefore studied in a Finnish cohort of adults.

METHODS

The data was collected from the Tampere adult population cardiovascular risk study (TAMRISK). A total of 279 cases with hypertension and/or coronary artery disease (CAD), and 488 non-hypertensive healthy controls were selected from a Finnish periodic health examination 50-year-old cohort. Information was available also from their 45-year examination. DNA was extracted from buccal swabs and human syndecan-4 gene SNPs were analyzed using KASP genotyping.

RESULTS

The SNP rs1981429 variant TT was significantly associated with hypertension, as compared to variants TG and GG at the age of 50 years (p=0.015). The variant TT was also associated with increased BMI at the ages of 45 and 50 years (p=0.008 and p=0.026, respectively). In addition, TT genotype associated with increased CAD prevalence (P=0.013). No significant associations between rs4599 variants and hypertension or BMI were found. In haplotype analysis the number of alleles T (rs1981429)/C (rs4599) was linearly associated with CAD prevalence; the highest prevalence (13%) was in haplotype TT/CC and lowest prevalence (1%) in haplotype GG/TT (p=0.01).

CONCLUSION

Syndecan-4 polymorphisms were associated with essential hypertension, BMI, and CAD prevalence in the TAMRISK study.

Novel extracellular matrix biomarkers as predictors of adverse outcome in chronic heart failure: association between biglycan and response to statin therapy in the CORONA trial

BACKGROUND

The extracellular matrix (ECM) plays an important role in left ventricular remodeling and progression of heart failure (HF). Biglycan and mimecan are ECM proteins that are abundantly expressed in cardiac tissue but have not been evaluated as prognostic markers in HF. We investigated their interaction with statin treatment and association with adverse outcome in chronic HF.

METHODS AND RESULTS

The association between serum levels of biglycan and mimecan and the primary end point (cardiovascular [CV] death, nonfatal myocardial infarction, nonfatal stroke), all-cause mortality, CV death, the composite of all-cause mortality/hospitalization for worsening of HF, and the coronary end point was evaluated in 1,390 patients >60 years of age with ischemic systolic HF in the Controlled Rosuvastatin Multinational Trial in HF (CORONA) population, randomly assigned to 10 mg rosuvastatin or placebo. Serum biglycan and mimecan added no prognostic information beyond conventional risk factors, including N-terminal pro-B-type natriuretic peptide. However, statin treatment improved all outcomes except CV death in patients with low biglycan levels (ie, lower tertile), even after full multivariable adjustment.

CONCLUSIONS

Although circulating levels of mimecan and biglycan were of limited predictive value in patients with chronic HF, circulating biglycan could be a useful marker for targeting statin therapy in patients with HF.

Emerging biomarkers for heart failure: an update

A growing array of biological pathways underpins the syndrome we recognize as heart failure. These include both deleterious pathways promoting its development and progression, as well as compensatory cardioprotective pathways. Components of these pathways can be utilized as biomarkers of this condition to aid diagnosis, prognostication and potentially guide management. As our understanding of the pathophysiology of heart failure deepens further candidate biomarkers are being identified. We provide an overview of the more recently emerging biomarkers displaying potential promise for future clinical use.

Vascular biomechanical properties in mice with smooth muscle specific deletion of Ndst1

Heparan sulfate proteoglycans act as co-receptors for many chemokines and growth factors. The sulfation pattern of the heparan sulfate chains is a critical regulatory step affecting the binding of chemokines and growth factors. N-deacetylase-N-sulfotransferase1 (Ndst1) is one of the first enzymes to catalyze sulfation. Previously published work has shown that HSPGs alter tangent moduli and stiffness of tissues and cells. We hypothesized that loss of Ndst1 in smooth muscle would lead to significant changes in heparan sulfate modification and the elastic properties of arteries. In line with this hypothesis, the axial tangent modulus was significantly decreased in aorta from mice lacking Ndst1 in smooth muscle (SM22αcre(+)Ndst1(-/-), p < 0.05, n = 5). The decrease in axial tangent modulus was associated with a significant switch in myosin and actin types and isoforms expressed in aorta and isolated aortic vascular smooth muscle cells. In contrast, no changes were found in the compliance of smaller thoracodorsal arteries of SM22αcre(+)Ndst1(-/-) mice. In summary, the major findings of this study were that targeted ablation of Ndst1 in smooth muscle cells results in altered biomechanical properties of aorta and differential expression of myosin and actin types and isoforms.

Integrating the myocardial matrix into heart failure recognition and management

In contrast to public perception, the morbidity and mortality and the resultant healthcare costs associated with chronic heart failure (HF) are increasing and arguably reaching epidemic proportions. Although basic research efforts have provided unique insights into fundamental processes that govern myocardial extracellular matrix (ECM) growth and function, the translation of these findings to improved diagnostics and therapeutics for HF has not been as forthcoming. The factors that contribute to this relative paucity of new clinical tools for HF are multifactorial but likely include the need to recognize and differentiate HF phenotypes and to couple the use of biomarkers and multimodality imaging in early translational research studies. Recognizing the classification scheme of HF with a reduced ejection fraction (EF) to that of HF with a preserved EF and incorporating unique and differential measurements of ECM remodeling to these specific disease processes are warranted. For example, profiling pathways of ECM degradation such as the matrix metalloproteinases in patients with ischemic heart disease and HF with a reduced EF can provide prognostic information in terms of risk of progression to HF. In patients with chronic hypertensive disease and HF with a preserved EF, plasma profiling indexes of ECM synthesis and turnover, as well as advances in ECM imaging, have been shown to provide diagnostic and prognostic use. In terms of therapeutics, strategies to stabilize the ECM in HF with a reduced EF hold potential, whereas in contradistinction, selective antifibrotic agents may hold promise for HF with a preserved EF.

Experimental biomarkers in heart failure: an update

Over the past 5 years, researchers have examined the utility of many experimental heart failure biomarkers that are not yet widely adopted clinically, to complement the role of B-type natriuretic peptide and its precursor. Candidate biomarkers have been identified from several different pathophysiologic categories, including markers of inflammation, myocyte necrosis, renal dysfunction, neurohumoral activation, oxidative stress and raised intracardiac pressure. Indeed, some biomarkers provide prognostic information that is independent of information obtained from conventional clinical and biomarker assessment. Moreover, some biomarkers studied help to identify dominant pathology that may predict responsiveness to specific therapies. Preliminary data also suggest a potential role for the development of comprehensive biomarker profiling models, integrating biomarkers from several categories to refine risk assessment.

Single molecule detection of glycosaminoglycan hyaluronic acid oligosaccharides and depolymerization enzyme activity using a protein nanopore

Glycosaminoglycans are biologically active anionic carbohydrates that are among the most challenging biopolymers with regards to their structural analysis and functional assessment. The potential of newly introduced biosensors using protein nanopores that have been mainly described for nucleic acids and protein analysis to date, has been here applied to this polysaccharide-based third class of bioactive biopolymer. This nanopore approach has been harnessed in this study to analyze the hyaluronic acid glycosamiglycan and its depolymerization-derived oligosaccharides. The translocation of a glycosaminoglycan is reported using aerolysin protein nanopore. Nanopore translocation of hyaluronic acid oligosaccharides was evidenced by the direct detection of translocated molecules accumulated into the arrival compartment using high-resolution mass spectrometry. Anionic oligosaccharides of various polymerization degrees were discriminated through measurement of the dwelling time and translocation frequency. This molecular sizing capability of the protein nanopore device allowed the real-time recording of the enzymatic cleavage of hyaluronic acid polysaccharide. The time-resolved detection of enzymatically produced oligosaccharides was carried out to monitor the depolymerization enzyme reaction at the single-molecule level.

Serum tenascin-C levels as a prognostic biomarker of heart failure events in patients with hypertrophic cardiomyopathy

BACKGROUND AND PURPOSE

Although serum tenascin-C (TN-C) levels are related to left ventricular (LV) remodeling in patients with myocardial infarction and are useful as a prognostic biomarker of heart failure in patients with dilated cardiomyopathy, the clinical significance of TN-C levels has not yet been studied in patients with hypertrophic cardiomyopathy (HCM). Therefore, the purpose of this study is to elucidate whether serum TN-C levels are a prognostic biomarker for heart failure in patients with HCM.

METHODS

The relationship between serum TN-C levels and heart failure events was studied in 36 patients with HCM during follow-up.

RESULTS

Levels of serum TN-C were 28±13 ng/ml (range 11-80 ng/ml). Although patients with LV systolic impairment showed higher TN-C levels than those with preserved LV systolic function (33±11 ng/ml vs. 27±14 ng/ml; p=0.16), TN-C levels were not related to any echocardiographic parameters. During the follow-up period of 4.8±1.4 years, heart failure events were observed in six patients and TN-C levels in patients with events were higher than those in patients without events. Kaplan-Meier analysis showed that the prognosis was worse in patients with high TN-C levels (≥39.2 ng/ml) than in those with low TN-C levels.

CONCLUSIONS

Heart failure events were more frequently observed in patients with high serum TN-C levels than in those with low TN-C levels. Serum TN-C levels may be a new prognostic biomarker for heart failure in patients with HCM.