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.

A reduction in the vascular smooth muscle cell focal adhesion component syndecan-4 is associated with abdominal aortic aneurysm formation

BACKGROUND

Abdominal aortic aneurysm (AAA) is a serious vascular disease for which there is no effective drug treatment. The incidence of AAA increases significantly as a subject ages, and the molecular mechanism of AAA formation remains elusive. In the present study, we investigated the role of syndecan-4 (SDC4), an important component of focal adhesions, in AAA formation and its association with phenotypic changes in vascular smooth muscle cells (VSMCs).

METHODS AND RESULTS

The protein expression levels of SDC4 were significantly decreased in human AAA tissue and those of an AAA mouse model. Moreover, SDC4 knockout (KO) in mice accelerated the formation and rupture of AAAs induced by angiotensin II (Ang II) and calcium chloride (CaCl2 ) Mechanistically, the decrease in SDC4 led to the transformation of cultured VSMCs from a contractile to a secretory phenotype. The RhoA-F/G-actin-myocardin-related transcription factor-A (MRTF-A) signalling pathway was shown to be involved in SDC4-dependent VSMC alteration. Sphingosine-1-phosphate (S1P), a G-protein-coupled receptor, attenuated the AAA formation in SDC4-KO and wild-type (WT) mice in response to Ang II and CaCl2 stimulation.

CONCLUSION

We herein demonstrated that silencing SDC4 was associated with increased AAA formation and phenotypic changes in VSMCs via the RhoA-F/G-actin-MRTF-A pathway. These findings indicated that a reduction in SDC4 expression was an important pathological alteration and potential therapeutic target for AAA formation.

Circulating Levels of the Heparan Sulfate Proteoglycan Syndecan-4 Positively Associate with Blood Pressure in Healthy Premenopausal Women

Syndecans (SDCs) are transmembrane proteins that are present on most cell types where they play a role in multiple physiological processes, including cell-matrix adhesion and inflammation. Growing evidence suggests that elevated levels of both shed SDC1 and SDC4 are associated with hypertension and cardiovascular diseases, but their relationships with cardiovascular risk factors in healthy individuals are unknown. The primary objective of this study was to investigate whether serum levels of SDC4 and SDC1 were associated with body composition, hemodynamic parameters, pro-inflammatory cytokine concentrations, and urinary noradrenaline and dopamine levels in healthy women (17 African American and 20 European American) between the ages of 20 and 40 years old. Univariate analyses revealed only a significant (p < 0.05) inverse correlation between serum SDC1 and body fat percentage. On the other hand, serum SDC4 was positively correlated with systolic blood pressure, diastolic blood pressure, and urinary levels of noradrenaline and dopamine. Serum SDC4 was also a significant predictor of systolic blood pressure in a multivariate regression model that included fat-free mass and urinary dopamine levels as significant independent variables. The result did not change even adjusting for race. Our findings indicate that SDC4 has an important role in the physiological regulation of blood pressure.

Association Between Factors Involved in Bone Remodeling (Osteoactivin and OPG) With Plasma Levels of Irisin and Meteorin-Like Protein in People With T2D and Obesity

The musculoskeletal system consisting of bones and muscles have been recognized as endocrine organs secreting hormones that are involved in regulating metabolic and inflammatory pathways. Obesity and type 2 diabetes (T2D) are associated with several musculoskeletal system complications. We hypothesized that an interaction exists between adipomyokines namely, irisin and METRNL, and various molecules involved in bone remodeling in individuals with obesity and T2D. A total of 228 individuals were enrolled in this study, including 124 non-diabetic (ND) and 104 T2D. A Multiplex assay was used to assess the level of various osteogenic molecules namely osteoactivin, Syndecan, osteoprotegerin (OPG) and osteonectin/SPARC. Our data shows elevated levels of Osteoactivin, Syndecan, OPG and SPARC in T2D as compared to ND individuals (p ≤ 0.05). Using Spearman's correlation, a positive correlation was observed between irisin and Osteoactivin as well as OPG (p < 0.05). Similarly, a positive association was observed between METRNL and Osteoactivin (p < 0.05). The strong positive association shown in this study between irisin, METRNL and various molecules with osteogenic properties emphasize a possible interaction between these organs. This report suggests that having a dysregulation in the level of the aforementioned molecules could potentially affect the development of bone and muscle related complications that are associated with obesity and T2D.

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.

Increased syndecan-4 expression in sera and skin of patients with atopic dermatitis

Syndecan-4 (SDC-4) is a cell surface proteoglycan, which participates in signaling during cell adhesion, migration, proliferation, endocytosis, and mechanotransduction, and is expressed on various cells, including endothelial cells, epithelial cells, T cells, and eosinophils. Emerging evidences have suggested that SDC-4 might contribute to Th2-driven allergic immune responses. Here, we examined the role of SDC-4 in patients with atopic dermatitis (AD). Serum SDC-4 levels in AD patients were significantly higher than in healthy individuals, and they increased according to the disease severity. Importantly, they positively correlated with Eczema Area and Severity Index and itch visual analogue scale scores. Furthermore, serum SDC-4 levels decreased after treatment. We also analyzed SDC-4 expression in AD lesional skin. SDC-4 mRNA levels in AD skin were significantly higher than those of normal skin. Immunohistochemical staining revealed that SDC-4 was highly expressed in the epidermis and endothelial cells in AD lesional skin. Taken together, our study has demonstrated that SDC-4 expression was increased in sera and skin of AD patients, suggesting that SDC-4 may contribute to the development of AD.

The multi-biomarker approach for heart failure in patients with hypertension

We assessed the predictive ability of selected biomarkers using N-terminal pro-brain natriuretic peptide (NT-proBNP) as the benchmark and tried to establish a multi-biomarker approach to heart failure (HF) in hypertensive patients. In 120 hypertensive patients with or without overt heart failure, the incremental predictive value of the following biomarkers was investigated: Collagen III N-terminal propeptide (PIIINP), cystatin C (CysC), lipocalin-2/NGAL, syndecan-4, tumor necrosis factor-α (TNF-α), interleukin 1 receptor type I (IL1R1), galectin-3, cardiotrophin-1 (CT-1), transforming growth factor β (TGF-β) and N-terminal pro-brain natriuretic peptide (NT-proBNP). The highest discriminative value for HF was observed for NT-proBNP (area under the receiver operating characteristic curve (AUC) = 0.873) and TGF-β (AUC = 0.878). On the basis of ROC curve analysis we found that CT-1 > 152 pg/mL, TGF-β < 7.7 ng/mL, syndecan > 2.3 ng/mL, NT-proBNP > 332.5 pg/mL, CysC > 1 mg/L and NGAL > 39.9 ng/mL were significant predictors of overt HF. There was only a small improvement in predictive ability of the multi-biomarker panel including the four biomarkers with the best performance in the detection of HF—NT-proBNP, TGF-β, CT-1, CysC—compared to the panel with NT-proBNP, TGF-β and CT-1 only. Biomarkers with different pathophysiological backgrounds (NT-proBNP, TGF-β, CT-1, CysC) give additive prognostic value for incident HF in hypertensive patients compared to NT-proBNP alone.

[Changes and clinical significance of serum level of syndecan-4 protein in patients with chronic congestive heart failure]

OBJECTIVE

To detect serum level of syndecan-4 protein in patients with chronic congestive heart failure (CHF) and investigate its correlation with New York Heart Association (NYHA) class and echocardiographic parameters.

METHODS

The concentration of serum syndecan-4 protein was measured by enzyme-linked immunosorbent assay (ELISA) in 40 patients with CHF and 40 healthy controls (NCD), respectively. The parameters such as left ventricle ejection fraction (LVEF), fraction shortening (FS), left ventricle end-diastolic diameter (LVDd), left ventricle end-systolic diameter (LVDs), left ventricle end-diastolic volume (LVEDV) and left ventricle end-systolic volume (LVESV) were detected by echocardiography in 40 patients of CHF. Meanwhile, the patients' cardiac function was graded according to NYHA class.

RESULTS

The levels of serum syndecan-4 protein significantly increased in CHF group as compared with control group (P<0.01). In CHF group, as the increased grading of NYHA cardiac function, the levels of serum syndecan-4 protein significantly increased (P<0.05). The more upgraded the NYHA grading, the higher level of serum syndecan-4 protein. In bivariate correlations analysis showed that the level of serum syndecan-4 protein was significantly negatively correlated with LVEF and FS (P<0.05) and was significantly positively correlated with LVDd, LVDs, LVEDV and LVESV, respectively (P<0.05).

CONCLUSION

Serum syndecan-4 concentration significantly increased in CHF patients, and it was closely correlated with NYHA class and left ventricle function parameters, so the level of serum syndecan-4 protein may have an important value in detection and surveillance of CHF.