Vascular adhesion protein-1 and syndecan-1 in septic shock

Glycosaminoglycans: Participants in Microvascular Coagulation of Sepsis

Sepsis represents a syndromic response to infection and frequently acts as a common pathway leading to fatality in the context of various infectious diseases globally. The pathology of severe sepsis is marked by an excess of inflammation and activated coagulation. A substantial contributor to mortality in sepsis patients is widespread microvascular thrombosis-induced organ dysfunction. Multiple lines of evidence support the notion that sepsis induces endothelial damage, leading to the release of glycosaminoglycans, potentially causing microvascular dysfunction. This review aims to initially elucidate the relationship among endothelial damage, excessive inflammation, and thrombosis in sepsis. Following this, we present a summary of the involvement of glycosaminoglycans in coagulation, elucidating interactions among glycosaminoglycans, platelets, and inflammatory cells. In this section, we also introduce a reasoned generalization of potential signal pathways wherein glycosaminoglycans play a role in clotting. Finally, we discuss current methods for detecting microvascular conditions in sepsis patients from the perspective of glycosaminoglycans. In conclusion, it is imperative to pay closer attention to the role of glycosaminoglycans in the mechanism of microvascular thrombosis in sepsis. Dynamically assessing glycosaminoglycan levels in patients may aid in predicting microvascular conditions, enabling the monitoring of disease progression, adjustment of clinical treatment schemes, and mitigation of both acute and long-term adverse outcomes associated with sepsis.

Syndecan-1 as a prognostic biomarker in COVID-19 patients: a retrospective study of a Japanese cohort

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has had a profound global impact, with millions of confirmed cases and deaths worldwide. While most cases are mild, a subset progresses to severe respiratory complications and death, with factors such as thromboembolism, age, and underlying health conditions increasing the risk. Vascular endothelial damage has been implicated in severe outcomes, but specific biomarkers remain elusive. This study investigated syndecan-1 (SDC-1), a marker of endothelial damage, as a potential prognostic factor for COVID-19, focusing on the Japanese population, which is known for its aging demographics and high prevalence of comorbidities.

METHODS

A multicenter retrospective study of COVID-19 patients in Fukushima Prefecture in Japan who were admitted between February 2020 and August 2021 was conducted. SDC-1 levels were measured along with other clinical and laboratory parameters. Outcomes including thrombosis, 28-day survival, and disease severity were assessed, and disease severity was categorized according to established guidelines.

RESULTS

SDC-1 levels were correlated with disease severity. Patients who died from COVID-19 had greater SDC-1 levels than survivors, and the area under the receiver operating characteristic curve (AUC) analysis suggested the potential of the SDC-1 level as a predictor of mortality (AUC 0.714). K‒M analysis also revealed a significant difference in survival based on an SDC-1 cutoff of 10.65 ng/mL.

DISCUSSION

This study suggested that SDC-1 may serve as a valuable biomarker for assessing COVID-19 severity and predicting mortality within 28 days of hospitalization, particularly in the Japanese population. However, further investigations are required to assess longitudinal changes in SDC-1 levels, validate its predictive value for long-term survival, and consider its applicability to new viral variants.

CONCLUSIONS

SDC-1 is emerging as a potential biomarker for assessing the severity and life expectancy of COVID-19 in the Japanese population, offering promise for improved risk stratification and patient management in the ongoing fight against the virus.

Sedation with propofol and isoflurane differs in terms of microcirculatory parameters: A randomized animal study using dorsal skinfold chamber mouse model

OBJECTIVE

This study aimed to explore the effects of sedative doses of propofol and isoflurane on microcirculation in septic mice compared to controls. Isoflurane, known for its potential as a sedation drug in bedside applications, lacks clarity regarding its impact on the microcirculation system. The hypothesis was that propofol would exert a more pronounced influence on the microvascular flow index, particularly amplified in septic conditions.

MATERIAL AND METHODS

Randomized study was conducted from December 2020 to October 2021 involved 60 BALB/c mice, with 52 mice analyzed. Dorsal skinfold chambers were implanted, followed by intraperitoneal injections of either sterile 0.9 % saline or lipopolysaccharide for the control and sepsis groups, respectively. Both groups received propofol or isoflurane treatment for 120 min. Microcirculatory parameters were obtained via incident dark-field microscopy videos, along with the mean blood pressure and heart rate at three time points: before sedation (T0), 30 min after sedation (T30), and 120 min after sedation (T120). Endothelial glycocalyx thickness and syndecan-1 concentration were also analyzed.

RESULTS

In healthy controls, both anesthetics reduced blood pressure. However, propofol maintained microvascular flow, differing significantly from isoflurane at T120 (propofol, 2.8 ± 0.3 vs. isoflurane, 1.6 ± 0.9; P < 0.001). In the sepsis group, a similar pattern occurred at T120 without statistical significance (propofol, 1.8 ± 1.1 vs. isoflurane, 1.2 ± 0.7; P = 0.023). Syndecan-1 levels did not differ between agents, but glycocalyx thickness index was significantly lower in the isoflurane-sepsis group than propofol (P = 0.001).

CONCLUSIONS

Propofol potentially offers protective action against microvascular flow deterioration compared to isoflurane, observed in control mice. Furthermore, a lower degree of sepsis-induced glycocalyx degradation was evident with propofol compared to isoflurane.

Syndecan-1 levels predict septic shock in critically ill patients with COVID-19

BACKGROUND

The clinical picture of coronavirus disease 2019 (COVID-19)-associated sepsis is similar to that of sepsis of other aetiologies. The present study aims to analyse the role of syndecan-1 (SDC-1) as a potential predictor of septic shock in critically ill patients with COVID-19.

METHODS

This is a prospective study of 86 critically ill patients due to COVID-19 infection. Patients were followed until day 28 of hospitalization. Vascular biomarkers, such as vascular cell adhesion protein-1, SDC-1, angiopoietin-1 and angiopoietin-2, were quantified upon admission and associated with the need for vasopressors in the first 7 d of hospitalization.

RESULTS

A total of 86 patients with COVID-19 (mean age 60±16 y; 51 men [59%]) were evaluated. Thirty-six (42%) patients died during hospitalization and 50 (58%) survived. The group receiving vasopressors had higher levels of D-dimer (2.46 ng/ml [interquartile range {IQR} 0.6-6.1] vs 1.01 ng/ml [IQR 0.62-2.6], p=0.019) and lactate dehydrogenase (929±382 U/l vs 766±312 U/l, p=0.048). The frequency of deaths during hospitalization was higher in the group that received vasoactive amines in the first 24 h in the intensive care unit (70% vs 30%, p=0.002). SDC-1 levels were independently associated with the need for vasoactive amines, and admission values >269 ng/ml (95% CI 0.524 to 0.758, p=0.024) were able to predict the need for vasopressors during the 7 d following admission.

CONCLUSIONS

Syndecan-1 levels predict septic shock in critically ill patients with COVID-19.

Identification of immune infiltration and immune-related biomarkers of periprosthetic joint infection

Background

The immune response associated with periprosthetic joint infection (PJI) is an emerging but relatively unexplored topic. The aim of this study was to investigate immune cell infiltration in periprosthetic tissues and identify potential immune-related biomarkers.

Methods

The GSE7103 dataset from the GEO database was selected as the data source. Differentially expressed genes (DEGs) and significant modular genes in weighted correlation network analysis (WGCNA) were identified. Functional enrichment analysis and transcription factor prediction were performed on the overlapping genes. Next, immune-related genes from the ImmPort database were matched. The protein-protein interaction (PPI) analysis was performed to identify hub genes. CIBERSORTx was used to evaluate the immune cell infiltration pattern. Spearman correlation analysis was used to evaluate the relationship between hub genes and immune cells.

Results

A total of 667 DEGs were identified between PJI and control samples, and 1847 PJI-related module genes were obtained in WGCNA. Enrichment analysis revealed that the common genes were mainly enriched in immune and host defense-related terms. TFEC, SPI1, and TWIST2 were the top three transcription factors. Three hub genes, SDC1, MMP9, and IGF1, were identified in the immune-related PPI network. Higher levels of plasma cells, CD4+ memory resting T cells, follicular helper T cells, resting mast cells, and neutrophils were found in the PJI group, while levels of M0 macrophages were lower. Notably, the expression of all three hub genes correlated with the infiltration levels of seven types of immune cells.

Conclusion

The present study revealed immune infiltration signatures in the periprosthetic tissues of PJI patients. SDC1, MMP9, and IGF1 were potential immune-related biomarkers for PJI.

Acute pyelonephritis in pregnancy and plasma syndecan-1: evidence of glycocalyx involvement

BACKGROUND

Acute pyelonephritis, a risk factor for maternal sepsis, adult respiratory distress syndrome, and preterm labor, is a frequent cause of hospitalization. This condition is characterized by excessive intravascular inflammation and endothelial cell activation and dysfunction. Syndecan-1, a major component of the glycocalyx, is a gel-like layer that covers the luminal surface of healthy endothelial cells, preserving and mediating many endothelial functions. During pregnancy, there is an additional potential source of syndecan-1, the "syncytiotrophoblast glycocalyx," which lines the intervillous space. Insults that damage the glycocalyx lead to a shedding of syndecan-1 into the circulation. Hence, syndecan-1 has been proposed as a marker of endothelial injury in conditions such as sepsis, trauma, cardiovascular disease, and diabetes mellitus.

OBJECTIVE

The objective of this study was to determine whether the plasma syndecan-1 concentration changes in women with acute pyelonephritis in the presence or absence of bacteremia.

STUDY DESIGN

This cross-sectional study included three groups: (1) non-pregnant women (n = 25); (2) women with an uncomplicated pregnancy from whom samples were collected preterm (n = 61) or at term (n = 69); and (3) pregnant women diagnosed with acute pyelonephritis from whom samples were collected at the time of diagnosis during the second and third trimesters (n = 33). The diagnosis of acute pyelonephritis was based on clinical findings and a positive urine culture for bacteria. Blood culture results were available in 85% (28/33) of women with acute pyelonephritis. Plasma concentrations of syndecan-1 were determined by a validated immunoassay.

RESULTS

(1) Women with an uncomplicated pregnancy had a higher plasma concentration of syndecan-1 than non-pregnant women. The geometric mean (95% confidence interval [CI]) of syndecan-1 concentration was 51.0 (12.1-216.1) ng/mL in non-pregnant controls; 1280 (365-4487) ng/mL in normal preterm gestations; and 1786 (546-5834) ng/mL in normal term gestations (adjusted p < .005 for all three between group comparisons); (2) plasma syndecan-1 concentrations increased with gestational age among women with a normal pregnancy (p < .001, R² = 0.27); (3) syndecan-1 multiple of the mean (MoM) values in pregnant patients with acute pyelonephritis were higher than those in normal pregnant women based on second- and third-trimester samples (p = .048, 1.26-fold change). The increase was driven primarily by cases with a positive blood culture (p = .009, 1.74-fold change); (4) when data from third-trimester samples were compared, overall differences in syndecan-1 MoM values between cases and controls were slightly larger (p = .03, 1.36- fold change), which were especially contributed to by cases with a positive blood culture (p = .023, fold change 1.79-fold change).

CONCLUSIONS

Plasma syndecan-1 concentration is higher in pregnant women and increases as a function of gestational age. Patients with acute pyelonephritis have a higher plasma concentration of syndecan-1, and this is particularly the case in the presence of bacteremia.

Fluid restrictive resuscitation with high molecular weight hyaluronan infusion in early peritonitis sepsis

Sepsis is a condition with high morbidity and mortality. Prompt recognition and initiation of treatment is essential. Despite forming an integral part of sepsis management, fluid resuscitation may also lead to volume overload, which in turn is associated with increased mortality. The optimal fluid strategy in sepsis resuscitation is yet to be defined. Hyaluronan, an endogenous glycosaminoglycan with high affinity to water is an important constituent of the endothelial glycocalyx. We hypothesized that exogenously administered hyaluronan would counteract intravascular volume depletion and contribute to endothelial glycocalyx integrity in a fluid restrictive model of peritonitis. In a prospective, blinded model of porcine peritonitis sepsis, we randomized animals to intervention with hyaluronan (n = 8) or 0.9% saline (n = 8). The animals received an infusion of 0.1% hyaluronan 6 ml/kg/h, or the same volume of saline, during the first 2 h of peritonitis. Stroke volume variation and hemoconcentration were comparable in the two groups throughout the experiment. Cardiac output was higher in the intervention group during the infusion of hyaluronan (3.2 ± 0.5 l/min in intervention group vs 2.7 ± 0.2 l/min in the control group) (p = 0.039). The increase in lactate was more pronounced in the intervention group (3.2 ± 1.0 mmol/l in the intervention group and 1.7 ± 0.7 mmol/l in the control group) at the end of the experiment (p < 0.001). Concentrations of surrogate markers of glycocalyx damage; syndecan 1 (0.6 ± 0.2 ng/ml vs 0.5 ± 0.2 ng/ml, p = 0.292), heparan sulphate (1.23 ± 0.2 vs 1.4 ± 0.3 ng/ml, p = 0.211) and vascular adhesion protein 1 (7.0 ± 4.1 vs 8.2 ± 2.3 ng/ml, p = 0.492) were comparable in the two groups at the end of the experiment. In conclusion, hyaluronan did not counteract intravascular volume depletion in early peritonitis sepsis. However, this finding is hampered by the short observation period and a beneficial effect of HMW-HA in peritonitis sepsis cannot be discarded based on the results of the present study.

Endothelial Dysfunction in Patients Undergoing Cardiac Surgery: A Narrative Review and Clinical Implications

Cardiac surgery is one of the highest-risk procedures, usually involving cardiopulmonary bypass and commonly inducing endothelial injury that contributes to the development of perioperative and postoperative organ dysfunction. Substantial scientific efforts are being made to unravel the complex interaction of biomolecules involved in endothelial dysfunction to find new therapeutic targets and biomarkers and to develop therapeutic strategies to protect and restore the endothelium. This review highlights the current state-of-the-art knowledge on the structure and function of the endothelial glycocalyx and mechanisms of endothelial glycocalyx shedding in cardiac surgery. Particular emphasis is placed on potential strategies to protect and restore the endothelial glycocalyx in cardiac surgery. In addition, we have summarized and elaborated the latest evidence on conventional and potential biomarkers of endothelial dysfunction to provide a comprehensive synthesis of crucial mechanisms of endothelial dysfunction in patients undergoing cardiac surgery, and to highlight their clinical implications.

Elevated endothelial dysfunction-related biomarker levels indicate the severity and predict sepsis incidence

This study was conducted to investigate the relationship between serum endothelial dysfunction-related biomarker levels and organ dysfunction severity in septic patients and the predictive value of these levels during sepsis. In total, 105 patients admitted to the Department of Critical Care Medicine were enrolled between September 2020 and November 2021. Serum syndecan-1 and soluble thrombomodulin(sTM) levels were measured by enzyme-linked immunosorbent assay, and clinical and laboratory data were recorded. Enroll patients were divided into the infection (n = 28), septic nonshock (n = 31), and septic shock (n = 46) groups . Serum syndecan-1 (102.84 ± 16.53 vs. 55.38 ± 12.34 ng/ml), and sTM(6.60 ± 1.44 ng/ml vs. 5.23 ± 1.23 ng/ml, P < 0.01) levels were increased in the septic group compared with those in the infection group. Serum syndecan-1 levels were closely positively correlated with serum sTM (r_s = 0.712, r² = 0.507, P < 0.001). Additionally, serum syndecan-1(r_s = 0.687, r² = 0.472, P < 0.001) and sTM levels (r_s = 0.6, r² = 0.36, P < 0.01) levels were significantly positively correlated with the sequential organ failure assessment scores respectively. Syndecan-1 (AUC 0.95 ± 0.02, P < 0.0001) was more valuable for prediction sepsis than was sTM (AUC 0.87 ± 0.04, P < 0.0001). Compared with sTM (AUC 0.88 ± 0.03, P < 0.001), syndecan-1 (AUC 0.95 ± 0.02, P < 0.001) and SOFA score (AUC 0.95 ± 0.02, P < 0.001) were better predictors of septic shock. Serum syndecan-1 and sTM levels were associated with organ dysfunction severity in septic patients, and both were good predictors for early identification of sepsis, particularly in patients undergoing septic shock.

Plasma syndecan‐1 concentration as a biomarker for endothelial glycocalyx degradation in septic adult horses

BACKGROUND

Limited information is available regarding endothelial glycocalyx degradation during sepsis in horses. Plasma syndecan-1 concentrations are increased in consequence of sepsis in other species and have been useful for prognostication.

OBJECTIVES

To determine whether plasma syndecan-1 levels are increased in adult horses affected with sepsis.

STUDY DESIGN

Retrospective cohort study.

METHODS

Adult horses were assigned to one of three groups based on results of physical and laboratory examinations, clinical diagnosis, and results of previously described SIRS classification: Group 1 horses included healthy, nonseptic horses; Group 2 included horses in which clinical illness was identified but that were not considered to be septic; Group 3 included horses with a clinical diagnosis of sepsis. Plasma syndecan-1 concentration was determined in blood obtained at admission into the hospital for each horse, using an equine specific ELISA. Data were analysed using ANOVA and linear regression (p ≤ 0.05).

RESULTS

One hundred and ninety-one horses were included and divided into three groups. Scores for SIRS were highest for Group 3 horses and lowest in Groups 1 and 2. Plasma syndecan-1 concentrations in Group 3 horses (50.73 ± 84.24 μg/ml; n = 42) were greater than those for Group 1 (15.69 ± 11.28 μg/ml; n = 66) and Group 2 (16.88 ± 15.30 μg/ml; n = 83). There was no difference regarding syndecan concentrations between Groups 1 and 2.

MAIN LIMITATIONS

Retrospective study design, solitary time point of measurement for each patient, and lack of a widely accepted consensus regarding definitive diagnosis of sepsis in adult horses.

CONCLUSIONS

Circulating plasma levels of syndecan-1, a biochemical marker of endothelial glycocalyx damage, are increased in septic adult horses.

Prognostic Value of Syndecan-1 in the Prediction of Sepsis-Related Complications and Mortality: A Meta-Analysis

Aim

Syndecan-1 (SDC-1) has been shown to have a high predictive value for sepsis development, though uncertainty around these results exists. The aim of this meta-analysis was to assess the prognostic ability of SDC-1 in predicting sepsis-related complications and mortality.

Methods

We searched PubMed, EMBASE, Cochrane Library, and Google Scholar databases from January 01, 1990, to March 17, 2021, to identify eligible studies. The search terms used were “SDC-1,” “sepsis,” “severe sepsis,” and “septic shock,” and a meta-analysis was performed using the RevMan 5.4 software.

Results

Eleven studies with a total of 2,318 enrolled patients were included. SDC-1 concentrations were significantly higher in the composite poor outcome group [standardized mean difference (SMD) = 0.55; 95% CI: 0.38–0.72; P < 0.001] as well as in deceased patients (SMD = 0.53; 95% CI: 0.40–0.67; P < 0.001), patients with septic shock (SMD = 0.81; 95% CI: 0.36–1.25; P < 0.001), and patients with acute kidney injury (SMD = 0.48; 95% CI: 0.33–0.62; P < 0.001). Statistical significance was also found in the subgroup analysis when stratified by different sepsis diagnostic criteria.

Conclusion

Baseline SDC-1 levels may be a useful predictor of sepsis-related complications and mortality.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021246344, PROSPERO, identifier: CRD42021246344.

Emodin relieves the inflammation and pyroptosis of lipopolysaccharide-treated 1321N1 cells by regulating methyltransferase-like 3 -mediated NLR family pyrin domain containing 3 expression

Sepsis brain injury (SBI) is a major cause of death in critically ill patients. The present study aimed to investigate the role of emodin in SBI development. Human astrocyte 1321N1 cells were stimulated with 100 ng/mL lipopolysaccharide (LPS) to establish an SBI model in vitro. Flow cytometry was performed to measure the cell pyroptosis. The protein expression levels of syndecan-1 (SDC-1), NLR family pyrin domain containing 3 (NLRP3), Caspase-1, and the N-terminal fragment of gasdermin D (GSDMD-N) were measured using Western blotting. Interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor (TNF)-α levels in cells were measured using enzyme-linked immunosorbent assay kits. The N⁶-methyladenosine (m⁶A) modification was analyzed using the methylated RNA immunoprecipitation assay. NLRP3 activator, nigericin, was used to overexpress NLRP3. LPS treatment significantly enhanced the pyroptosis in 1321N1 cells, increased the levels of TNF-α, IL-1β, and IL-6, and decreased the levels of IL-10. The protein expression levels of NLRP3, SDC-1, GSDMD-N, and Caspase-1 were also increased. Emodin treatment decreased the levels of TNF-α, IL-1β, IL-6, NLRP3, SDC-1, GSDMD-N, and Caspase-1, while increasing the levels of IL-10 in LPS-treated 1321N1 cells. Nigericin reversed the effects of emodin. Furthermore, emodin upregulated m⁶A levels in NLRP3 by increasing the expression of methyltransferase-like 3 (METTL3). Meanwhile, knockdown of METTL3 reversed the effects of emodin on the mRNA expression and stability of NLRP3. Therefore, emodin inhibits the inflammation and pyroptosis of LPS-treated 1321N1 cells by inactivating METTL3-mediated NLRP3 expression.

The Role of Heparin and Glycocalyx in Blood-Brain Barrier Dysfunction

The blood-brain barrier (BBB) functions as a dynamic boundary that protects the central nervous system from blood and plays an important role in maintaining the homeostasis of the brain. Dysfunction of the BBB is a pathophysiological characteristic of multiple neurologic diseases. Glycocalyx covers the luminal side of vascular endothelial cells(ECs). Damage of glycocalyx leads to disruption of the BBB, while inhibiting glycocalyx degradation maintains BBB integrity. Heparin has been recognized as an anticoagulant and it protects endothelial glycocalyx from destruction. In this review, we summarize the role of glycocalyx in BBB formation and the therapeutic potency of heparin to provide a theoretical basis for the treatment of neurological diseases related to BBB breakdown.

Colivelin, a synthetic derivative of humanin, ameliorates endothelial injury and glycocalyx shedding after sepsis in mice

Endothelial dysfunction plays a central role in the pathogenesis of sepsis-mediated multiple organ failure. Several clinical and experimental studies have suggested that the glycocalyx is an early target of endothelial injury during an infection. Colivelin, a synthetic derivative of the mitochondrial peptide humanin, has displayed cytoprotective effects in oxidative conditions. In the current study, we aimed to determine the potential therapeutic effects of colivelin in endothelial dysfunction and outcomes of sepsis in vivo. Male C57BL/6 mice were subjected to a clinically relevant model of polymicrobial sepsis by cecal ligation and puncture (CLP) and were treated with vehicle or colivelin (100-200 µg/kg) intraperitoneally at 1 h after CLP. We observed that vehicle-treated mice had early elevation of plasma levels of the adhesion molecules ICAM-1 and P-selectin, the angiogenetic factor endoglin and the glycocalyx syndecan-1 at 6 h after CLP when compared to control mice, while levels of angiopoietin-2, a mediator of microvascular disintegration, and the proprotein convertase subtilisin/kexin type 9, an enzyme implicated in clearance of endotoxins, raised at 18 h after CLP. The early elevation of these endothelial and glycocalyx damage biomarkers coincided with lung histological injury and neutrophil inflammation in lung, liver, and kidneys. At transmission electron microscopy analysis, thoracic aortas of septic mice showed increased glycocalyx breakdown and shedding, and damaged mitochondria in endothelial and smooth muscle cells. Treatment with colivelin ameliorated lung architecture, reduced organ neutrophil infiltration, and attenuated plasma levels of syndecan-1, tumor necrosis factor-α, macrophage inflammatory protein-1α and interleukin-10. These therapeutic effects of colivelin were associated with amelioration of glycocalyx density and mitochondrial structure in the aorta. At molecular analysis, colivelin treatment was associated with inhibition of the signal transducer and activator of transcription 3 and activation of the AMP-activated protein kinase in the aorta and lung. In long-term outcomes studies up to 7 days, co-treatment of colivelin with antimicrobial agents significantly reduced the disease severity score when compared to treatment with antibiotics alone. In conclusion, our data support that damage of the glycocalyx is an early pathogenetic event during sepsis and that colivelin may have therapeutic potential for the treatment of sepsis-associated endothelial dysfunction.

Role of heparinase in the gastrointestinal dysfunction of sepsis (Review)

Heparinase (HPA) is a β-D glucuronidase that belongs to the endoglycosidase enzyme family, and plays an important role in numerous pathological and physiological processes, including inflammation, angiogenesis and tumor metastasis. When the expression of HPA is abnormally high, the side chain of heparin sulfate proteoglycans degrades, destroying the cell barrier and leading to the occurrence and development of inflammation, with systemic inflammation occurring in severe cases. Sepsis is a major cause of mortality in critically ill patients. In sepsis, the gastrointestinal tract is the first and most frequently involved target organ, which often leads to gastrointestinal dysfunction. HPA overexpression has been determined to accelerate sepsis progression and gastrointestinal dysfunction; thus, it was hypothesized that HPA may play an important role and may serve as an index for the diagnosis of gastrointestinal dysfunction in sepsis. HPA inhibitors may therefore become applicable as targeted drugs for the treatment of gastrointestinal dysfunction in patients with sepsis. The present review mainly discussed the role of HPA in gastrointestinal dysfunction of sepsis.

Unfractionated Heparin Attenuated Histone-Induced Pulmonary Syndecan-1 Degradation in Mice: a Preliminary Study on the Roles of Heparinase Pathway

Endothelial glycocalyx degradation is thought to facilitate the development of sepsis. Histone is a significant mediator in sepsis. Unfractionated heparin (UFH) possessed beneficial effects on sepsis. Thereby, this study aims to figure out whether histone can disrupt glycocalyx and to investigate the protective effect and mechanism of UFH. Male mice (C57BL/6, 8-10 weeks old, weighing 20-25 g) were randomly divided into five groups including control group, histone group, histone + UFH group, histone + heparinase (HPA) inhibitor group, and histone + UFH + HPA inhibitor group. The mice were treated with histone (50 mg/kg) via tail vein immediately after HPA (20 mg/kg) injection. UFH (400 U/kg) was injected 1h after histone administration. The other groups were injected with equal volume of sterile saline accordingly. UFH alleviated histone-induced lung injury and pulmonary edema. UFH inhibited histone-induced lung coagulation activation and inflammatory response. UFH treatment markedly inhibited pulmonary glycocalyx degradation by reducing the histone-induced decrease in the levels of lung syndecan-1 mRNA and protein. UFH downregulated histone-induced expression of HPA mRNA and protein, and thus alleviated glycocalyx degradation. UFH protects against histone-induced pulmonary glycocalyx injury partly by heparinase pathway.

The Endothelial Glycocalyx as a Double-Edged Sword in Microvascular Homeostasis and Pathogenesis

Expressed on the endothelial cell (EC) surface of blood vessels, the glycocalyx (GCX), a mixture of carbohydrates attached to proteins, regulates the access of cells and molecules in the blood to the endothelium. Besides protecting endothelial barrier integrity, the dynamic microstructure of the GCX confers remarkable functions including mechanotransduction and control of vascular tone. Recently, a novel perspective has emerged supporting the pleiotropic roles of the endothelial GCX (eGCX) in cardiovascular health and disease. Because eGCX degradation occurs in certain pathological states, the circulating levels of eGCX degradation products have been recognized to have diagnostic or prognostic values. Beyond their biomarker roles, certain eGCX fragments serve as pathogenic factors in disease progression. Pharmacological interventions that attenuate eGCX degradation or restore its integrity have been sought. This review provides our current understanding of eGCX structure and function across the microvasculature in different organs. We also discuss disease or injury states, such as infection, sepsis and trauma, where eGCX dysfunction contributes to severe inflammatory vasculopathy.

Resuscitative Strategies to Modulate the Endotheliopathy of Trauma: From Cell to Patient

Clinical data has supported the early use of plasma in high ratios of plasma to red cells to patients in hemorrhagic shock. The benefit from plasma seems to extend beyond its hemostatic effects to include protection to the post-shock dysfunctional endothelium. Resuscitation of the endothelium by plasma and one of its major constituents, fibrinogen, involves cell surface stabilization of syndecan-1, a transmembrane proteoglycan and the protein backbone of the endothelial glycocalyx. The pathogenic role of miRNA-19b to the endothelium is explored along with the PAK-1-mediated intracellular pathway that may link syndecan-1 to cytoskeletal protection. Additionally, clinical studies using fibrinogen and cyroprecipitate to aid in hemostasis of the bleeding patient are reviewed and new data to suggest a role for plasma and its byproducts to treat the dysfunctional endothelium associated with nonbleeding diseases is presented.

Human glycocalyx shedding: Systematic review and critical appraisal

BACKGROUND

The number of studies measuring breakdown products of the glycocalyx in plasma has increased rapidly during the past decade. The purpose of the present systematic review was to assess the current knowledge concerning the association between plasma concentrations of glycocalyx components and structural assessment of the endothelium.

METHODS

We performed a literature review of Pubmed to determine which glycocalyx components change in a wide variety of human diseases and conditions. We also searched for evidence of a relationship between plasma concentrations and the thickness of the endothelial glycocalyx layer as obtained by imaging methods.

RESULTS

Out of 3,454 publications, we identified 228 that met our inclusion criteria. The vast majority demonstrate an increase in plasma glycocalyx products. Sepsis and trauma are most frequently studied, and comprise approximately 40 publications. They usually report 3-4-foldt increased levels of glycocalyx degradation products, most commonly of syndecan-1. Surgery shows a variable picture. Cardiac surgery and transplantations are most likely to involve elevations of glycocalyx degradation products. Structural assessment using imaging methods show thinning of the endothelial glycocalyx layer in cardiovascular conditions and during major surgery, but thinning does not always correlate with the plasma concentrations of glycocalyx products. The few structural assessments performed do not currently support that capillary permeability is increased when the plasma levels of glycocalyx fragments in plasma are increased.

CONCLUSIONS

Shedding of glycocalyx components is a ubiquitous process that occurs during both acute and chronic inflammation with no sensitivity or specificity for a specific disease or condition.

Serum syndecan-1 reflects organ dysfunction in critically ill patients

Syndecan-1 (SDC-1) is found in the endothelial glycocalyx and shed into the blood during systemic inflammatory conditions. We investigated organ dysfunction associated with changing serum SDC-1 levels for early detection of organ dysfunction in critically ill patients. To evaluate the effect of SDC-1 on laboratory parameters measured the day after SDC-1 measurement with consideration for repeated measures, linear mixed effects models were constructed with each parameter as an outcome variable. A total of 94 patients were enrolled, and 831 samples were obtained. Analysis using mixed effects models for repeated measures with adjustment for age and sex showed that serum SDC-1 levels measured the day before significantly affected several outcomes, including aspartate aminotransferase (AST), alanine transaminase (ALT), creatinine (CRE), blood urea nitrogen (BUN), antithrombin III, fibrin degradation products, and D-dimer. Moreover, serum SDC-1 levels of the prior day significantly modified the effect between time and several outcomes, including AST, ALT, CRE, and BUN. Additionally, increasing serum SDC-1 level was a significant risk factor for mortality. Serum SDC-1 may be a useful biomarker for daily monitoring to detect early signs of kidney, liver and coagulation system dysfunction, and may be an important risk factor for mortality in critically ill patients.

Impact of Anesthetic Agents on Endothelial Glycocalyx Injury during Total Knee Arthroplasty: Desflurane- vs. Propofol-Based Anesthesia-A Prospective Randomized Controlled Trial

Background

Ischemia-reperfusion injury and inflammation after tourniquet deflation in total knee arthroplasty are known to be associated with endothelial glycocalyx (EG) injury. This study is aimed at comparing EG injury between desflurane- and propofol-based anesthesia in patients undergoing total knee arthroplasty.

Materials and Methods

Patients were allocated to the desflurane group or propofol group. The opioid remifentanil was administered intraoperatively in both groups. Blood samples were obtained from the arterial line preoperatively, immediately before and 5 min after tourniquet deflation, and at 1, 6, and 24 h, postoperatively. Serum syndecan-1, cytokines (interleukin-1β, 6, 10, and tumour necrosis factor-α), and other laboratory values were investigated.

Results

Eighty patients were included in the final analysis. The change in syndecan-1 did not significantly differ between the desflurane and propofol groups (peak median level of syndecan-1; 754.5 pg/ml vs. 780.3 pg/ml, respectively, P = 0.512). Laboratory values (serum cytokines, creatinine phosphokinase, lactate dehydrogenase, and lactate levels) were also similar between the two groups. Pulmonary oxygenation was briefly improved after tourniquet deflation in the desflurane group but was similar between the two groups begging at 1 h, postoperatively.

Conclusions

The effect of desflurane was not superior to that of propofol in protecting the EG from ischemia-reperfusion injury during total knee arthroplasty. This trial is registered with Trial Registry Number NCT02756715 (http://clinicaltrials.gov).

The effects of sepsis on endothelium and clinical implications

ABSTRACT

Sepsis accounts for nearly 700 000 deaths in Europe annually and is caused by an overwhelming host response to infection resulting in organ failure. The endothelium is an active contributor to sepsis and as such represents a major target for therapy. During sepsis, endothelial cells amplify the immune response and activate the coagulation system. They are both a target and source of inflammation and serve as a link between local and systemic immune responses. In response to cytokines produced by immune cells, the endothelium expresses adhesion molecules and produces vasoactive compounds, inflammatory cytokines, and chemoattractants, thus switching from an anticoagulant to procoagulant state. These responses contribute to local control of infection, but systemic activation can lead to microvascular thrombosis, capillary permeability, hypotension, tissue hypoxia, and ultimately tissue damage. This review focuses on the role of the endothelium in leucocyte adhesion and transmigration as well as production of reactive oxygen and nitrogen species, microRNAs and cytokines, formation of signalling microparticles, and disseminated intravascular coagulation. We also discuss alterations in endothelial permeability and apoptosis. Finally, we review the diagnostic potential of endothelial markers and endothelial pathways as therapeutic targets for this devastating disease.

Fluids in ARDS: more pros than cons

In acute respiratory distress syndrome (ARDS), increased pulmonary vascular permeability makes the lung vulnerable to edema. The use of conservative as compared to liberal fluid strategies may increase the number of ventilator-free days and survival, as well as reduce organ dysfunction. Monitoring the effects of fluid administration is of the utmost importance; dynamic indexes, such as stroke volume and pulse pressure variations, outperform static ones, such as the central venous pressure. The passive leg raise and end-expiratory occlusion tests are recommended for guiding fluid management decisions. The type of intravenous fluids should also be taken into consideration: crystalloids, colloids, and human albumin have all been used for fluid resuscitation. Recent studies have also shown differences in outcome between balanced and non-balanced intravenous solutions. In preclinical studies, infusion of albumin promotes maintenance of the glycocalyx layer, reduces inflammation, and improves alveolar-capillary membrane permeability. Fluids in ARDS must be administered cautiously, considering hemodynamic and perfusion status, oncotic and hydrostatic pressures, ARDS severity, fluid type, volume and infusion rate, and cardiac and renal function. Of note, no guideline to date has recommended a specific fluid composition for use in ARDS; most physicians currently follow recommendations for sepsis.

Heparanase-enhanced Shedding of Syndecan-1 and Its Role in Driving Disease Pathogenesis and Progression

Both heparanase and syndecan-1 are known to be present and active in disease pathobiology. An important feature of syndecan-1 related to its role in pathologies is that it can be shed from the surface of cells as an intact ectodomain composed of the extracellular core protein and attached heparan sulfate and chondroitin sulfate chains. Shed syndecan-1 remains functional and impacts cell behavior both locally and distally from its cell of origin. Shedding of syndecan-1 is initiated by a variety of stimuli and accomplished predominantly by the action of matrix metalloproteinases. The accessibility of these proteases to the core protein of syndecan-1 is enhanced, and shedding facilitated, when the heparan sulfate chains of syndecan-1 have been shortened by the enzymatic activity of heparanase. Interestingly, heparanase also enhances shedding by upregulating the expression of matrix metalloproteinases. Recent studies have revealed that heparanase-induced syndecan-1 shedding contributes to the pathogenesis and progression of cancer and viral infection, as well as other septic and non-septic inflammatory states. This review discusses the heparanase/shed syndecan-1 axis in disease pathogenesis and progression, the potential of targeting this axis therapeutically, and the possibility that this axis is widespread and of influence in many diseases.

Overview of the Assessment of Endothelial Function in Humans

The endothelium is recognized to play an important role in various physiological functions including vascular tone, permeability, anticoagulation, and angiogenesis. Endothelial dysfunction is increasingly recognized to contribute to pathophysiology of many disease states, and depending on the disease stimuli, mechanisms underlying the endothelial dysfunction may be markedly different. As such, numerous techniques to measure different aspects of endothelial dysfunction have been developed and refined as available technology improves. Current available reviews on quantifying endothelial dysfunction generally concentrate on a single aspect of endothelial function, although diseases may affect more than one aspect of endothelial function. Here, we aim to provide an overview on the techniques available for the assessment of the different aspects of endothelial function in humans, human tissues or cells, namely vascular tone modulation, permeability, anticoagulation and fibrinolysis, and the use of endothelial biomarkers as predictors of outcomes.

Endothelial dysfunction is an early indicator of sepsis and neutrophil degranulation of septic shock in surgical patients

Background

Stratification of the severity of infection is currently based on the Sequential Organ Failure Assessment (SOFA) score, which is difficult to calculate outside the ICU. Biomarkers could help to stratify the severity of infection in surgical patients.

Methods

Levels of ten biomarkers indicating endothelial dysfunction, 22 indicating emergency granulopoiesis, and six denoting neutrophil degranulation were compared in three groups of patients in the first 12 h after diagnosis at three Spanish hospitals.

Results

There were 100 patients with infection, 95 with sepsis and 57 with septic shock. Seven biomarkers indicating endothelial dysfunction (mid‐regional proadrenomedullin (MR‐ProADM), syndecan 1, thrombomodulin, angiopoietin 2, endothelial cell‐specific molecule 1, vascular cell adhesion molecule 1 and E‐selectin) had stronger associations with sepsis than infection alone. MR‐ProADM had the highest odds ratio (OR) in multivariable analysis (OR 11·53, 95 per cent c.i. 4·15 to 32·08; P = 0·006) and the best area under the curve (AUC) for detecting sepsis (0·86, 95 per cent c.i. 0·80 to 0·91; P < 0·001). In a comparison of sepsis with septic shock, two biomarkers of neutrophil degranulation, proteinase 3 (OR 8·09, 1·34 to 48·91; P = 0·028) and lipocalin 2 (OR 6·62, 2·47 to 17·77; P = 0·002), had the strongest association with septic shock, but lipocalin 2 exhibited the highest AUC (0·81, 0·73 to 0·90; P < 0·001).

Conclusion

MR‐ProADM and lipocalin 2 could be alternatives to the SOFA score in the detection of sepsis and septic shock respectively in surgical patients with infection.

The Emerging Role of Vitamin C as a Treatment for Sepsis

Sepsis, a life-threatening organ dysfunction due to a dysregulated host response to infection, is a leading cause of morbidity and mortality worldwide. Decades of research have failed to identify any specific therapeutic targets outside of antibiotics, infectious source elimination, and supportive care. More recently, vitamin C has emerged as a potential therapeutic agent to treat sepsis. Vitamin C has been shown to be deficient in septic patients and the administration of high dose intravenous as opposed to oral vitamin C leads to markedly improved and elevated serum levels. Its physiologic role in sepsis includes attenuating oxidative stress and inflammation, improving vasopressor synthesis, enhancing immune cell function, improving endovascular function, and epigenetic immunologic modifications. Multiple clinical trials have demonstrated the safety of vitamin C and two recent studies have shown promising data on mortality improvement. Currently, larger randomized controlled studies are underway to validate these findings. With further study, vitamin C may become standard of care for the treatment of sepsis, but given its safety profile, current treatment can be justified with compassionate use.

Association of endothelial and glycocalyx injury biomarkers with fluid administration, development of acute kidney injury, and 90-day mortality: data from the FINNAKI observational study

Background

Injury to endothelium and glycocalyx predisposes to vascular leak, which may subsequently lead to increased fluid requirements and worse outcomes. In this post hoc study of the prospective multicenter observational Finnish Acute Kidney Injury (FINNAKI) cohort study conducted in 17 Finnish intensive care units, we studied the association of Syndecan-1 (SDC-1), Angiopoetin-2 (Ang-2), soluble thrombomodulin (sTM), vascular adhesion protein-1 (VAP-1) and interleukin-6 (IL-6) with fluid administration and balance among septic critical care patients and their association with development of acute kidney injury (AKI) and 90-day mortality.

Results

SDC-1, Ang-2, sTM, VAP-1 and IL-6 levels were measured at ICU admission from 619 patients with sepsis. VAP-1 decreased (p < 0.001) and IL-6 increased (p < 0.001) with increasing amounts of administered fluid, but other biomarkers did not show differences according to fluid administration. In linear regression models adjusted for IL-6, only VAP-1 was significantly associated with fluid administration on day 1 (p < 0.001) and the cumulative fluid balance on day 5/ICU discharge (p = 0.001). Of 415 patients admitted without AKI, altogether 112 patients (27.0%) developed AKI > 12 h from ICU admission (AKI_>12 h). They had higher sTM levels than patients without AKI, and after multivariable adjustment log, sTM level was associated with AKI_>12 h with OR (95% CI) of 12.71 (2.96–54.67), p = 0.001). Ninety-day non-survivors (n = 180; 29.1%) had higher SDC-1 and sTM levels compared to survivors. After adjustment for known confounders, log SDC-1 (OR [95% CI] 2.13 [1.31–3.49], p = 0.002), log sTM (OR [95% CI] 7.35 [2.29–23.57], p < 0.001), and log Ang-2 (OR [95% CI] 2.47 [1.44–4.14], p = 0.001) associated with an increased risk for 90-day mortality. Finally, patients who had high levels of all three markers, namely, SDC-1, Ang-2 and sTM, had an adjusted OR of 5.61 (95% CI 2.67–11.79; p < 0.001) for 90-day mortality.

Conclusions

VAP-1 and IL-6 associated with fluid administration on the first ICU day. After adjusting for confounders, sTM was associated with development of AKI after 12 h from ICU admission. SDC-1, Ang-2 and sTM were independently associated with an increased risk for 90-day mortality.

The association of endothelial injury and systemic inflammation with perioperative myocardial infarction

Background

Major surgery predisposes to endothelial glycocalyx injury. Endothelial glycocalyx injury associates with cardiac morbidity, including spontaneous myocardial infarction. However, the relation between endothelial glycocalyx injury and the development of perioperative myocardial infarction remains unknown.

Methods

Fifteen perioperative myocardial infarction patients and 60 propensity-matched controls were investigated in this prospective study. The diagnosis of perioperative myocardial infarction was based on repeated cardiac troponin T measurements, electrocardiographs and recordings of ischaemic signs and symptoms. We measured endothelial glycocalyx markers – soluble thrombomodulin, syndecan-1 and vascular adhesion protein 1 – and an inflammatory marker, namely interleukin-6, preoperatively and 6 h and 24 h postoperatively. We calculated the areas under the receiver operating characteristics curves (AUCs) to compare the performances of the different markers in predicting perioperative myocardial infarction. The highest value of each marker was used in the analysis.

Results

The interleukin-6 concentrations of perioperative myocardial infarction patients were significantly higher preoperatively and 6 and 24 h postoperatively ( P =  0.002, P =  0.002 and P =  0.001, respectively). The AUCs (95% confidence intervals) for the detection of perioperative myocardial infarction were 0.51 (0.34–0.69) for soluble thrombomodulin, 0.63 (0.47–0.79) for syndecan-1, 0.54 (0.37–0.70) for vascular adhesion protein 1 and 0.69 (0.54–0.85) for interleukin-6.

Conclusions

Systemic inflammation, reflected by interleukin-6, associates with cardiac troponin T release and perioperative myocardial infarction. Circulating interleukin-6 demonstrated some potential to predict perioperative myocardial infarction, whereas endothelial glycocalyx markers did not.

Endothelial Nanomechanics in the Context of Endothelial (Dys)function and Inflammation

SIGNIFICANCE

Stiffness of endothelial cells is closely linked to the function of the vasculature as it regulates the release of vasoactive substances such as nitric oxide (NO) and reactive oxygen species. The outer layer of endothelial cells, consisting of the glycocalyx above and the cortical zone beneath the plasma membrane, is a vulnerable compartment able to adapt its nanomechanical properties to any changes of forces exerted by the adjacent blood stream. Sustained stiffening of this layer contributes to the development of endothelial dysfunction and vascular pathologies. Recent Advances: The development of specific techniques to quantify the mechanical properties of cells enables the detailed investigation of the mechanistic link between structure and function of cells.

CRITICAL ISSUES

Challenging the mechanical stiffness of cells, for instance, by inflammatory mediators can lead to the development of endothelial dysfunction. Prevention of sustained stiffening of the outer layer of endothelial cells in turn improves endothelial function.

FUTURE DIRECTIONS

The mechanical properties of cells can be used as critical marker and test system for the proper function of the vascular system. Pharmacological substances, which are able to improve endothelial nanomechanics and function, could take a new importance in the prevention and treatment of vascular diseases. Thus, detailed knowledge acquisition about the structure/function relationship of endothelial cells and the underlying signaling pathways should be promoted.

The glycocalyx: a novel diagnostic and therapeutic target in sepsis

The glycocalyx is a gel-like layer covering the luminal surface of vascular endothelial cells. It is comprised of membrane-attached proteoglycans, glycosaminoglycan chains, glycoproteins, and adherent plasma proteins. The glycocalyx maintains homeostasis of the vasculature, including controlling vascular permeability and microvascular tone, preventing microvascular thrombosis, and regulating leukocyte adhesion.During sepsis, the glycocalyx is degraded via inflammatory mechanisms such as metalloproteinases, heparanase, and hyaluronidase. These sheddases are activated by reactive oxygen species and pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin-1beta. Inflammation-mediated glycocalyx degradation leads to vascular hyper-permeability, unregulated vasodilation, microvessel thrombosis, and augmented leukocyte adhesion. Clinical studies have demonstrated the correlation between blood levels of glycocalyx components with organ dysfunction, severity, and mortality in sepsis.Fluid resuscitation therapy is an essential part of sepsis treatment, but overaggressive fluid therapy practices (leading to hypervolemia) may augment glycocalyx degradation. Conversely, fresh frozen plasma and albumin administration may attenuate glycocalyx degradation. The beneficial and harmful effects of fluid and plasma infusion on glycocalyx integrity in sepsis are not well understood; future studies are warranted.In this review, we first analyze the underlying mechanisms of glycocalyx degradation in sepsis. Second, we demonstrate how the blood and urine levels of glycocalyx components are associated with patient outcomes. Third, we show beneficial and harmful effects of fluid therapy on the glycocalyx status during sepsis. Finally, we address the concept of glycocalyx degradation as a therapeutic target.

Intravital imaging of a pulmonary endothelial surface layer in a murine sepsis model

Direct intravital imaging of an endothelial surface layer (ESL) in pulmonary microcirculation could be a valuable approach to investigate the role of a vascular endothelial barrier in various pathological conditions. Despite its importance as a marker of endothelial cell damage and impairment of the vascular system, in vivo visualization of ESL has remained a challenging technical issue. In this work, we implemented a pulmonary microcirculation imaging system integrated to a custom-design video-rate laser scanning confocal microscopy platform. Using the system, a real-time cellular-level microscopic imaging of the lung was successfully performed, which facilitated a clear identification of individual flowing erythrocytes in pulmonary capillaries. Subcellular level pulmonary ESL was identified in vivo by fluorescence angiography using a dextran conjugated fluorophore to label blood plasma and the red blood cell (RBC) exclusion imaging analysis. Degradation of ESL width was directly evaluated in a murine sepsis model in vivo, suggesting an impairment of pulmonary vascular endothelium and endothelial barrier dysfunction.

Study on expression of plasma sCD138 in patients with hemorrhagic fever with renal syndrome

BACKGROUND

Until now, there is non-specific treatment, and exploring early and novel biomarkers to determine the disease severity and prognosis of hemorrhagic fever with renal syndrome (HFRS) would be of importance for clinician to take systematic and timely intervention. This study observed the expression of plasma sCD138, a soluble component shedding from the glycocalyx (GCX) to the circulating blood, and evaluated its predictive value on disease severity and prognosis of HFRS.

METHODS

One hundred and seventy-six patients with HFRS who were treated at our center between January 2011 and December 2013 were randomly enrolled in this study. The patients were divided into a mild-type group, a moderate-type group, a severe-type group and a critical-type group according to the HFRS criteria for clinical classification. Thirty-five blood samples from healthy subjects were obtained as the controls. The concentrations of sCD138 were detected using enzyme linked immunosorbent assay (ELISA). The levels of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib), albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), white blood cells (WBC), platelets (PLT), glucose (GLU), blood urea nitrogen (BUN) and serum creatinine (Scr) in the samples were routinely tested. The levels of sCD138 among the different types were compared; the correlation among sCD138 and the laboratory parameters mentioned above were analyzed. The predictive effectiveness for prognosis of sCD138 was evaluated using the receiver operating characteristic (ROC) curve analysis.

RESULTS

Except for the mild-type, the levels of sCD138 in the moderate-, severe- and critical-type patients during the acute stage were significantly higher than that of the convalescent stage and the control (P<0.05). With the aggravation of the disease, the levels of sCD138 during the acute stage had an increasing tendency, while demonstrated no significant difference among the moderate-, severe- and critical-type patients (P>0.05). sCD138 was negatively correlated with Fib, PLT and ALB, and was positively correlated with WBC and AST (P<0.05). sCD138 demonstrated predictive effectiveness for prognosis with the area under the curve (AUC) of 0.778 (P<0.001).

CONCLUSION

Dynamic detection of plasma sCD138 might be benefit to evaluating the disease severity and prognosis of the patients with HFRS.

Endothelial glycocalyx degradation is more severe in patients with non-pulmonary sepsis compared to pulmonary sepsis and associates with risk of ARDS and other organ dysfunction

BACKGROUND

Disruption of the endothelial glycocalyx contributes to acute lung injury in experimental sepsis but has not been well studied in humans. To study glycocalyx degradation in sepsis-induced ARDS, we measured plasma levels of syndecan-1, a marker for glycocalyx degradation.

METHODS

The present study is a retrospective observational study of 262 ventilated medical ICU patients at risk of ARDS due to severe sepsis and APACHE II ≥ 25. Plasma syndecan-1 was measured at study enrollment. Primary analysis focused on the association between syndecan-1 levels and the development of ARDS, other organ dysfunction (Brussels criteria), or in-hospital mortality.

RESULTS

Overall, 135 (52%) patients developed ARDS. In patients with non-pulmonary sepsis, syndecan-1 levels were associated with ARDS (p = 0.05). Regardless of etiology of sepsis, higher syndecan-1 levels were associated with hepatic (p < 0.001), renal (p = 0.003), coagulation (p = 0.001), and circulatory (p = 0.02) failure as well as in-hospital mortality (p = 0.001), and there was a significant association between syndecan-1 levels and the number of vasopressors required in the first 24 h (p < 0.001). In addition, elevated syndecan levels were independently predictive of mortality in multivariable logistic regression adjusted for age and APACHE II score (odds ratio 1.85 per log increase in syndecan-1, 95% CI 1.056-3.241, p = 0.03).

CONCLUSION

The extent of endothelial glycocalyx degradation is associated with non-pulmonary organ dysfunction in subjects with sepsis and is associated with ARDS but only in the subgroup with non-pulmonary sepsis. Measurement of syndecan-1 levels in sepsis patients might be useful for identifying patients at high risk of organ dysfunction and mortality as well as those who could benefit from therapies targeted at protecting or restoring the glycocalyx.

Targeting the endothelial glycocalyx in acute critical illness as a challenge for clinical and laboratory medicine

The purpose of this manuscript is to review the role of endothelial glycocalyx (EG) in the field of critical and perioperative medicine and to discuss possible future directions for investigations in this area. Under physiological conditions, EG has several well-defined functions aimed to prevent the disruption of vessel wall integrity. Under pathological conditions, the EG represent one of the earliest sites of injury during inflammation. EG structure and function distortion contribute to organ dysfunction related to sepsis, trauma, or global ischemia of any origin. Discovering new therapeutic approaches (either pharmacological or non-pharmacological) aimed to protect the EG against injury represents a promising direction in clinical medicine. Further, the currently-used common interventions in the acutely ill - fluids, blood products, nutritional support, organ-supporting techniques (e.g. continuous renal replacement therapy, extracorporeal circulation), temperature modulation and many others - should be re-evaluated during acute illness in terms of their EG "friendliness". To assess new therapies that protect the EG, or to evaluate the effect of currently-used interventions on EG integrity, a relevant marker or method to determine EG damage is needed. Such marker or method should be available to clinicians within hours, preferably in the form of a point-of-care test at the bedside. Collaborative research between clinical disciplines and laboratory medicine is warranted, and targeting the EG represents major challenges for both.

Endothelial glycocalyx: basic science and clinical implications

The classic Starling principle proposed that microvascular fluid exchange was determined by a balance of hydrostatic and oncotic pressures relative to the vascular wall and this movement of water was regulated by gaps in the intercellular spaces. However, current literature on the endothelial glycocalyx (a jelly-like protective layer covering the luminal surface of the endothelium) has revised Starling's traditional concepts. This article aims to summarise the literature on the glycocalyx related to its basic science, clinical settings inciting injury, protective strategies and clinical perspectives. Perioperative damage to the glycocalyx structure can increase vascular permeability leading to interstitial fluid shifts, oedema, and increased surgical morbidity. Pathological shedding of the glycocalyx occurs in response to mechanical cellular stress, endotoxins, inflammatory mediators, atrial natriuretic peptide, ischaemia-reperfusion injury, free oxygen radicals and hyperglycaemia. Increased understanding of the endothelial glycocalyx may change perioperative fluid management, and therapeutic strategies aimed at its preservation may improve patient outcomes.

Hypoxia serves a key function in the upregulated expression of vascular adhesion protein‑1 in vitro and in a rat model of hemorrhagic shock

Hemorrhagic shock following major trauma results in mortality, but the function of vascular adhesion protein-1 (VAP-1), implicated in intracranial hemorrhage, remains unknown. This study aimed to determine whether expression of the AOC3 gene and its encoded protein, VAP-1, is altered by hypoxia. Rat hepatic sinusoidal endothelial cells (RHSECs) and rat intestinal microvascular endothelial cells (RIMECs) were transduced with a viral vector carrying AOC3, and AOC3 mRNA expression levels were measured by reverse transcription-quantitative polymerase chain reaction. VAP-1 protein expression levels were measured by western blot analysis and compared between normoxic and hypoxic conditions. Following this, AOC3 mRNA and VAP-1 protein expression levels in hepatic and intestinal tissues were assessed in a rat model of hemorrhagic shock with or without fluid resuscitation; and serum semicarbazide-sensitive amine oxidase (SSAO) activity was measured by fluorometric assays. The effects of 2-bromoethylamine (2-BEA) on AOC3/VAP-1 levels and 24 h survival were investigated. AOC3 mRNA and VAP-1 protein levels were increased in RHSECs and RIMECs by hypoxia, and in hepatic and intestinal tissues from rats following hemorrhagic shock. Hypoxia increased serum SSAO activity in these animals. 2-BEA reduced AOC3 mRNA and VAP-1 protein levels in hepatic and intestinal tissues from rats following hemorrhagic shock, and appeared to improve survival in animals not receiving resuscitation following hemorrhagic shock. In conclusion, hemorrhagic shock upregulates AOC3/VAP-1 expressions, and this potentially occurs via hypoxia. Therefore, inhibition of VAP-1 may be beneficial in the setting of hemorrhagic shock. Further studies are required to confirm these findings and to establish whether VAP-1 may be a valid target for the development of novel therapies for hemorrhagic shock.

The Endothelial Glycocalyx: New Diagnostic and Therapeutic Approaches in Sepsis

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. The endothelial glycocalyx is one of the earliest sites involved during sepsis. This fragile layer is a complex network of cell-bound proteoglycans, glycosaminoglycan side chains, and sialoproteins lining the luminal side of endothelial cells with a thickness of about 1 to 3 μm. Sepsis-associated alterations of its structure affect endothelial permeability and result in the liberation of endogenous damage-associated molecular patterns (DAMPs). Once liberated in the circulatory system, DAMPs trigger the devastating consequences of the proinflammatory cascades in sepsis and septic shock. In this way, the injury to the glycocalyx with the consecutive release of DAMPs contributes to a number of specific clinical effects of sepsis, including acute kidney injury, respiratory failure, and septic cardiomyopathy. Moreover, the extent of glycocalyx degradation serves as a marker of endothelial dysfunction and sepsis severity. In this review, we highlight the crucial role of the glycocalyx in sepsis as a diagnostic tool and discuss the potential of members of the endothelial glycocalyx serving as hopeful therapeutic targets in sepsis-associated multiple organ failures.

The glycocalyx and its significance in human medicine

Cells are covered by a surface layer of glycans that is referred to as the 'glycocalyx'. In this review, we focus on the role of the glycocalyx in vascular diseases (atherosclerosis, stroke, hypertension, kidney disease and sepsis) and cancer. The glycocalyx and its principal glycosaminoglycans [heparan sulphate (HS) and hyaluronic acid (HA)] and core proteins (syndecans and glypicans) are degraded in vascular diseases, leading to a breakdown of the vascular permeability barrier, enhanced access of leucocytes to the arterial intima that propagate inflammation and alteration of endothelial mechanotransduction mechanisms that protect against disease. By contrast, the glycocalyx on cancer cells is generally robust, promoting integrin clustering and growth factor signalling, and mechanotransduction of interstitial flow shear stress that is elevated in tumours to upregulate matrix metalloproteinase release which enhances cell motility and metastasis. HS and HA are consistently elevated on cancer cells and are associated with tumour growth and metastasis. Later, we will review the agents that might be used to enhance or protect the glycocalyx to combat vascular disease, as well as a different set of compounds that can degrade the cancer cell glycocalyx to suppress cell growth and metastasis. It is clear that what is beneficial for either vascular disease or cancer will not be so for the other. The overarching conclusions are that (i) the importance of the glycocalyx in human medicine is only beginning to be recognized, and (ii) more detailed studies of glycocalyx involvement in vascular diseases and cancer will lead to novel treatment modalities.

Low Soluble Syndecan-1 Precedes Preeclampsia

INTRODUCTION

Syndecan-1 (Sdc1; CD138) is a major transmembrane heparan sulfate proteoglycan expressed on the extracellular, luminal surface of epithelial cells and syncytiotrophoblast, thus comprising a major component of the glycocalyx of these cells. The "soluble" (shed) form of Sdc1 has paracrine and autocrine functions and is normally produced in a regulated fashion. We compared plasma soluble Sdc1 concentrations, in relation to placental Sdc1 expression, in uncomplicated (control) and preeclamptic pregnancies.

METHODS

We evaluated soluble Sdc1 across uncomplicated pregnancy, and between preeclamptic, gestational hypertensive and control patients at mid-pregnancy (20 weeks) and 3rd trimester by ELISA. Placental expression level of Sdc1 was compared between groups in relation to pre-delivery plasma soluble Sdc1. Participants were recruited from Magee-Womens Hospital.

RESULTS

In uncomplicated pregnancy, plasma soluble Sdc1 rose significantly in the 1st trimester, and reached an approximate 50-fold increase at term compared to post pregnancy levels. Soluble Sdc1 was lower at mid-pregnancy in women who later developed preeclampsia (P<0.05), but not gestational hypertension, compared to controls, and remained lower at late pregnancy in preeclampsia (P<0.01) compared to controls. Sdc1 was prominently expressed on syncytiotrophoblast of microvilli. Syncytiotrophoblast Sdc1 immunostaining intensities, and mRNA content in villous homogenates, were lower in preeclampsia vs. controls (P<0.05). Soluble Sdc1 and Sdc1 immunostaining scores were inversely associated with systolic blood pressures, and positively correlated with infant birth weight percentile.

CONCLUSION

Soluble Sdc1 is significantly lower before the clinical onset of preeclampsia, with reduced expression of Sdc1 in the delivered placenta, suggesting a role for glycocalyx disturbance in preeclampsia pathophysiology.