Assessing the predictive value of elevated postoperative syndecan-1 levels for progressive acute kidney injury and kidney replacement therapy necessity in adult cardiac surgery patients.

BACKGROUND: The development of acute kidney injury (AKI) post-cardiac surgery significantly increases patient morbidity and healthcare costs. Prior researches have established Syndecan-1 (SDC-1) as a potential biomarker for endothelial injury and subsequent acute kidney injury development. This study assessed whether postoperative SDC-1 levels could further predict AKI requiring kidney replacement therapy (AKI-KRT) and AKI progression. METHODS: In this prospective study, 122 adult cardiac surgery patients, who underwent valve or coronary artery bypass grafting (CABG) or a combination thereof and developed AKI within 48 h post-operation from May to September 2021, were monitored for the progression to stage 2-3 AKI or the need for KRT. We analyzed the predictive value of postoperative serum SDC-1 levels in relation to multiple endpoints. RESULTS: In the study population, 110 patients (90.2%) underwent cardiopulmonary bypass, of which thirty received CABG or combined surgery. Fifteen patients (12.3%) required KRT, and thirty-eight (31.1%) developed progressive AKI, underscoring the severe AKI incidence. Multivariate logistic regression indicated that elevated SDC-1 levels were independent risk factors for progressive AKI (OR = 1.006) and AKI-KRT (OR = 1.011). The AUROC for SDC-1 levels in predicting AKI-KRT and AKI progression was 0.892 and 0.73, respectively, outperforming the inflammatory cytokines. Linear regression revealed a positive correlation between SDC-1 levels and both hospital (ß = 0.014, p = 0.022) and ICU stays (ß = 0.013, p < 0.001). CONCLUSION: Elevated postoperative SDC-1 levels significantly predict AKI progression and AKI-KRT in patients following cardiac surgery. The study's findings support incorporating SDC-1 level monitoring into post-surgical care to improve early detection and intervention for severe AKI.

Circulating glycocalyx shedding products as biomarkers for evaluating prognosis of patients with out-of-hospital cardiac arrest after return of spontaneous circulation.

The endothelial glycocalyx is damaged in postcardiac arrest syndrome (PCAS), but the prognostic value is unknown. We aimed to observe the expression and prognostic value of glycocalyx shedding products, including syndecan-1 (SDC-1), hyaluronan (HA), and heparan sulfate (HS) in PCAS. Data on clinical and 28-day outcomes of seventy-one consecutive patients with out-of-hospital cardiac arrest (OHCA) after the return of spontaneous circulation (ROSC) were collected. SDC-1, HA, and HS were measured on days 0, 1, and 3 after ROSC. Thirty healthy individuals were controls. Glycocalyx shedding was observed in human umbilical vein endothelial cells (HUVECs) stimulated during hypoxia and reoxygenation in vitro. Within 4 h of ROSC, SDC-1 and HA levels, significantly increased. In the 28-day non-survivors, HA levels showed a gradual upward trend, SDC-1 remained at a high level, and HS levels first increased, then decreased. Kaplan-Meier curves and binary logistic regression analysis showed the prognostic value of SDC-1 levels on days 0, 1, and 3, HA levels on days 1 and 3, and HS levels on day 1. Only HS levels on day 1 showed a prognostic value for 28-day neurological outcomes. SDC-1 and HA levels were positively correlated with the no-flow time. In vitro, HUVECs showed shedding of SDC-1 and HS during a prolonged duration of hypoxia. After ROSC, SDC-1, HA, and HS levels may predict the 28-day survival after PCAS, and HS levels are associated with functional outcomes.

Evaluation of endothelial glycocalyx injury biomarkers in feline hemotropic mycoplasmosis.

The present study aimed to investigate endothelial glycocalyx (eGCx) damage in cats with feline hemotropic mycoplasmosis caused by Mycoplasma haemofelis using selected biomarkers and to determine the diagnostic and prognostic significance of these biomarkers. The study included 25 cats with feline hemotropic mycoplasmosis and 10 healthy cats. Clinical examination, blood gas analysis, complete blood count, and biochemical analysis were performed. Hemotropic mycoplasmosis diagnosed by microscopic examination and molecularly confirmed by PCR targeting the Mycoplasma haemofelis 16s rRNA gene. To evaluate endothelial glycocalyx damage, syndecan-1, endothelin-1 (ET-1), asymmetric dimethylarginine (ADMA), and vascular endothelial growth factor-A (VEGF-A) concentrations were measured using cat-specific commercial ELISA kits. Of the cats with feline hemotropic mycoplasmosis, 14 (56%) survived and 11 (44%) died. While syndecan-1 and ET-1 concentrations were significantly higher in cats with hemotropic mycoplasmosis compared to the control group (p < 0.001), no statistically significant difference was found for ADMA and VEGF-A concentrations (p > 0.05). Endothelial glycocalyx biomarkers showed significant correlations with each other and with hematological parameters (p < 0.01). The results of the ROC analysis showed that ET-1 with area under the curve (AUC) of 0.821 (p < 0.01) and VEGF-A with AUC of 0.805 (p < 0.010) were found to be significant prognostic indicators. In conclusion, this study demonstrated that serum syndecan-1 and ET-1 can be used as diagnostic and serum ET-1 and VEGF-A as prognostic biomarkers in cats with hemotropic mycoplasmosis. Our results indicate the development of eGCx damage in feline hemotropic mycoplasmosis and suggest that glycocalyx disruption may contribute to the pathogenesis of the disease.

Urinary syndecan-1 in dogs anesthetized with isoflurane or sevoflurane: A randomized, prospective study.

BACKGROUND: Syndecan-1 (SDC1) is an established marker of endothelial glycocalyx shedding. Most research on SDC1 has focused on plasma or serum concentrations, and little is known about urine concentrations. OBJECTIVES: Measure urinary SDC1 concentrations in dogs undergoing anesthesia with either sevoflurane or isoflurane and assess the effects of anesthesia duration and IV crystalloids on urinary SDC1 concentrations. ANIMALS: Thirty-one client-owned dogs undergoing anesthesia for magnetic resonance imaging (MRI) with or without surgery for suspected intervertebral disk disease (IVDD) were used. METHODS: Dogs with suspected IVDD were randomized to undergo anesthesia with either sevoflurane or isoflurane. Urine was collected before and immediately after anesthesia for the analysis of SDC1. Urinary creatinine concentrations also were measured, and the ratio of urinary SDC1 to urinary creatinine (USCR) was used to account for dilution. RESULTS: Median (range) USCR was significantly higher after anesthesia compared with baseline for all groups combined (P < .05). No significant difference was found between the groups for age, sex, weight, and type of anesthesia. Multiple regression analysis of the effect of the independent variables inhalant type, age, weight, sex, anesthesia time, surgery, and quantity of IV fluids on the dependent variable SDC1 found that only the quantity of IV fluids significantly predicted a change (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: The total volume of lactated Ringer's solution administered to anesthetized dogs may affect USCR. Further investigations are warranted to evaluate the relationship between IV fluids and SDC1.

The significance of Syndecan 1, a new marker for endothelial dysfunction, in cases of fetal growth retardation.

PROBLEM: In the current study we aimed to investigate Syndecan 1 (SDC1) levels in pregnant women diagnosed with fetal growth restriction (FGR) and the relationship between SDC1 levels and clinical and doppler parameters in FGR cases associated with endothelial dysfunction, angiogenesis and uteroplacental insufficiency METHOD OF STUDY: A total of 90 pregnant women included in the study, (45 with FGR, 45 healthy control) matched by week of gestation and maternal age. Venous blood samples were collected and plasma concentrations of SDC1 were determined by a specific immunoassay. Doppler examination was performed to evaluate the relationship between the SDC1 levels and placental blood supply. RESULTS: Doppler parameters; mean UtA-PI (p < .001), CPR (p = .002) and CPUR (p < .001) were different between the groups, however MCA PI, umbilical artery PI and umbilical artery S/D were not (p > .05). While gestational age at delivery, birth weight, APGAR score at 1 and 5 min were significantly lower (all, p < .001) in the study group, non-reassure fetal heart rate tracing (p = .09) and NICU admission (p = .02) were significantly higher. SDC 1 level was 2,00 ± 1,47 ng/mL and 2,34 ± 1,12 ng/mL in the FGR and control groups, respectively (p = .008). In the study group SDC 1 level was 1,69 ± 2,00 in those with gestational age below 32 weeks and 2,13 ± 1,18 in those with gestational age above 32 weeks and there was a statistically significant difference between the groups (p = .015). Plasma SDC 1 concentration of 2,1850 ng/mL or less had a sensitivity of 70%, a specificity of 72%, area under the ROC curve .65 (p < .005). CONCLUSIONS: Low maternal plasma SDC1 level may be associated with placental insufficiency and FGR. Low levels of SDC1 may be helpful as a predictor for the development of FGR during gestation.

Perioperative serum syndecan-1 concentrations in patients who underwent cardiovascular surgery with cardiopulmonary bypass and its association with the occurrence of postoperative acute kidney injury: a retrospective observational study.

BACKGROUND: Various factors can cause vascular endothelial damage during cardiovascular surgery (CVS) with cardiopulmonary bypass (CPB), which has been suggested to be associated with postoperative complications. However, few studies have specifically investigated the relationship between the degree of vascular endothelial damage and postoperative acute kidney injury (pAKI). The objectives of this study were to measure perioperative serum syndecan-1 concentrations in patients who underwent CVS with CPB, evaluate their trends, and determine their association with pAKI. METHODS: This was a descriptive and case‒control study conducted at the National University Hospital. Adult patients who underwent CVS with CPB at a national university hospital between March 15, 2016, and August 31, 2020, were included. Patients who were undergoing preoperative dialysis, had preoperative serum creatinine concentrations greater than 2.0 mg dl-1, who were undergoing surgery involving the descending aorta were excluded. The perioperative serum syndecan-1 concentration was measured, and its association with pAKI was investigated. RESULTS: Fifty-two patients were included. pAKI occurred in 18 (34.6%) of those patients. The serum syndecan-1 concentration increased after CPB initiation and exhibited bimodal peak values. The serum syndecan-1 concentration at all time points was significantly elevated compared to that after the induction of anesthesia. The serum syndecan-1 concentration at 30 min after weaning from CPB and on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.10 [1.01 to 1.21], P = 0.03]; OR = 1.16 [1.01 to 1.34], P = 0.04]; and the cutoff values of the serum syndecan-1 concentration that resulted in pAKI were 101.0 ng ml-1 (sensitivity = 0.71, specificity = 0.62, area under the curve (AUC) = 0.67 (0.51 to 0.83)) and 57.1 ng ml-1 (sensitivity = 0.82, specificity = 0.56, AUC = 0.71 (0.57 to 0.86)). Multivariate logistic regression analysis revealed that the serum syndecan-1 concentration on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.02 [1.00 to 1.03]; P = 0.03). CONCLUSION: The serum syndecan-1 concentration at all time points was significantly greater than that after the induction of anesthesia. The serum syndecan-1 concentration on postoperative day 1 was significantly associated with the occurrence of pAKI. TRIAL REGISTRATION: This study is not a clinical trial and is not registered with the registry.

Biomarkers of endothelial glycocalyx damage are associated with microvascular dysfunction in resuscitated septic shock patients.

BACKGROUND: Microvascular dysfunction plays a central role in organ dysfunction during septic shock. Endothelial glycocalyx (eGC) damage could contribute to impaired microcirculation. The aim was to assess whether several eGC-damaged biomarkers are associated with microvascular dysfunction in resuscitated septic shock patients. METHODS: This cross-sectional study included resuscitated septic shock patients (N = 31), and a group of healthy individuals (N = 20). The eGC damage biomarkers measured were syndecan-1 (SDC-1), soluble CD44 (CD44s), hyaluronic acid (HYAL) in blood sample; sulfated glycosaminoglycans (GAGs) in urine sample; and thrombomodulin (TBML) in blood sample as biomarker of endothelial cell damage. Microcirculation was assessed through sublingual videocapillaroscopy using the GlycoCheck™, which estimated the perfused vascular density (PVD); the perfused boundary region (PBR), an inverse parameter of the eGC thickness; and the microvascular health score (MVHS). We defined a low MVHS (<50th percentile in septic patients) as a surrogate for more impaired microvascular function. RESULTS: The SDC-1, CD44s, TBML and GAGs levels were correlated with impaired microvascular parameters (PVD of vessels with diameter < 10 µm, MVHS and flow-adjusted PBR); p < 0.05 for all comparisons, except for GAGs and flow-adjusted PBR. The SDC-1 [78 ng/mL (interquartile range (IQR) 45-336) vs. 48 ng/mL (IQR 9-85); p = 0.052], CD44s [796ρg/mL (IQR 512-1995) vs. 526ρg/mL (IQR 287-750); p = 0.036], TBML [734ρg/mL (IQR 237-2396) vs. 95ρg/mL (IQR 63-475); p = 0.012] and GAGs levels [0.42 ρg/mg (IQR 0.04-1.40) vs. 0.07 ρg/mg (IQR 0.02-0.20); p = 0.024]; were higher in septic patients with more impaired sublingual microvascular function (low MVHS vs. high MVHS). CONCLUSION: SDC-1, CD44s, TBML and GAGs levels were associated with impaired microvascular function in resuscitated septic shock patients.

Association of Preoperative and Postoperative Plasma Syndecan-1 and Colorectal Cancer Outcome.

BACKGROUND/AIM: A three-dimensional network constructed using glycocalyx (GCX) extends throughout the cancer cell nest in human colorectal cancer (CRC). GCX was found to be closely related to cancer. We examined the prognostic correlation and potential of syndecan-1 (SDC1), a representative proteoglycan of GCX, as a biomarker. PATIENTS AND METHODS: We analyzed SDC1 in the transcriptomic profiles of a major publicly available CRC cohort from The Cancer Genome Atlas (TCGA) using a computational algorithm. We investigated serum SDC1 levels preoperatively and on postoperative day seven in 48 patients with stage I-III CRC who underwent surgery during July-December 2019 at Gifu University Hospital. RESULTS: For TCGA, no significant differences existed between the high and low SDC1 expression groups regarding disease-free, disease-specific, and overall survival for stage I-III, and only overall survival for stage IV was significantly different. In our study, among the 48 patients, 17 (no recurrence), 13 (1 recurrence), and 18 (10 recurrences) had stage I-III, respectively. Preoperative and postoperative day 7 SDC1 levels for patients with stage I-III were 10.7±2.3 and 9.9±3.1 ng/ml (p=0.40), 11.1±1.7 and 10.1±0.8 ng/ml (p=0.07), and 10.3±2.0 and 9.5±1.4 ng/ml (p=0.15), respectively. In stage II and III, patients were divided into two groups according to differences between preoperative and postoperative SDC1 levels (SDC1pre-pro). SDC1pre-pro ≤0 group significantly prolonged disease-free survival compared with SDC1pre-pro >0 group (p=0.048). CONCLUSION: Dynamic change in serum SDC1 levels serves as a prognostic biomarker for stage II and III colorectal cancer.

Peripheral blood syndecan-1 levels after mechanical thrombectomy can predict the clinical prognosis of patients with acute ischemic stroke.

BACKGROUND: Previously, we revealed noticeable dynamic fluctuations in syndecan-1 levels in the peripheral blood of post-stroke patients. We further investigated the clinical prognostic value of syndecan-1 as a biomarker of glycoprotein damage in patients with acute ischaemic stroke (AIS). METHODS: We examined 105 patients with acute large vessel occlusion in the anterior circulation, all of whom underwent mechanical thrombectomy (MT). Peripheral blood syndecan-1 levels were measured 1 day after MT, and patients were categorised into favourable and unfavourable prognostic groups based on the 90-day modified Rankin Scale (mRS) score. Additionally, we compared the clinical outcomes between groups with high and low syndecan-1 concentrations. RESULTS: The findings revealed a significantly lower syndecan-1 level in the group with an unfavourable prognosis compared to those with a favourable prognosis (p < 0.01). In the multivariable logistic regression analysis, lower syndecan-1 levels were identified as a predictor of unfavourable prognosis (odds ratio (OR) = 0.965, p = 0.001). Patients displaying low syndecan-1 expression in the peripheral blood (< 29.51 ng/mL) experienced a > twofold increase in the rates of unfavourable prognosis and mortality. CONCLUSIONS: Our study demonstrates that syndecan-1, as an emerging, easily detectable stroke biomarker, can predict the clinical outcomes of patients with AIS. After MT, low levels of syndecan-1 in the peripheral blood on the first day emerged as an independent risk factor for an unfavourable prognosis, suggesting that lower syndecan-1 levels might signify worse clinical presentation and outcomes in stroke patients undergoing this procedure.

Doxycycline can reduce glycocalyx shedding by inhibiting matrix metalloproteinases in patients undergoing cardiopulmonary bypass: A randomized controlled trial.

BACKGROUND: Cardiopulmonary bypass (CPB) leads to shedding of the glycocalyx of endothelial cells, resulting in a series of complications such as tissue edema and coagulatory and microcirculatory dysfunctions. Matrix metalloproteinases (MMPs) can cause glycocalyx shedding in a variety of pathological processes, but their role in the process of CPB is still unclear. We hypothesized that the MMPs inhibitor doxycycline would reduce glycocalyx shedding by inhibiting MMPs during CPB. METHODS: Thirty-six patients were randomized to receive either 100 mg oral doxycycline (an MMPs inhibitor) or a matching placebo pill twice a day for three days before CPB. The primary outcome was the concentration of plasma syndecan-1. Secondary outcomes included heparan sulphate, MMP-2, MMP-9, ratio of urinary albumin to creatinine, and short-term clinical outcomes. In order to further prove that MMPs in plasma caused the glycocalyx shedding, human umbilical vein endothelial cells were cultured with plasma obtained from cardiac surgery patients before or after CPB (with or without MMPs inhibitor GM6001). The change in glycocalyx content was detected by immunofluorescence. RESULTS: CPB resulted in an increase of MMPs and shedding of the glycocalyx. Plasma syndecan-1 was higher in the control group than in the doxycycline group (median difference:15.04 µg/L; 95% CI: 9.14-20.94 µg/L; P < 0.001). Similar to syndecan-1, plasma heparan sulphate, MMP-2, and MMP-9 concentrations in the doxycycline group were significantly lower than those in the control group during CPB. Doxycycline was also correlated with a reduction in the ratio of urinary albumin to creatinine and improved the short-term clinical outcomes of patients. Endothelial cells cultured with plasma from patients after CPB showed significant shedding of syndecan-1 and heparan sulphate (post-CPB group vs pre-CPB group, P < 0.001). GM6001 was shown to reduce shedding of syndecan-1 and heparan sulphate by inhibiting MMPs (post-CPB + GM6001 group vs post-CPB group, P < 0.001). CONCLUSION: Doxycycline can reduce glycocalyx shedding by inhibiting MMPs during CPB.

Serum Syndecan-1: A Novel Biomarker for Pancreatic Ductal Adenocarcinoma.

INTRODUCTION: Syndecan-1 (SDC1) has multiple functions in tumorigenesis in general and specifically in pancreatic cancer. We aimed to evaluate SDC1 as a diagnostic and prognostic biomarker in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: In this case-control study, patients newly diagnosed with a biopsy-proven PDAC were enrolled alongside healthy individuals in a derivation-validation cohort design. Serum SDC1 was measured by enzyme-linked immunoassay. The diagnostic accuracy of SDC1 levels for diagnosing PDAC was computed. A unified cohort enriched with additional early-stage patients with PDAC was used to evaluate the association of SDC1 with survival outcomes and patient characteristics. RESULTS: In the derivation cohort, serum SDC1 levels were significantly higher in patients with PDAC (n = 39) compared with healthy controls (n = 20) (40.1 ng/mL, interquartile range 29.8-95.3 vs 25.6 ng/mL, interquartile range 17.1-29.8, respectively; P < 0.001). The receiver operating characteristic analysis area under the curve was 0.847 (95% confidence interval 0.747-0.947, P < 0.001). These results were replicated in a separate age-matched validation cohort (n = 38 PDAC, n = 38 controls; area under the curve 0.844, 95% confidence interval 0.757-0.932, P < 0.001). In the combined-enriched PDAC cohort (n = 110), using a cutoff of 35 ng/mL, the median overall 5-year survival between patients below and above this cutoff was not significantly different, although a trend for better survival after 1 year was found in the lower level group (P = 0.06). There were 12 of the 110 patients with PDAC (11%) who had normal CA 19-9 in the presence of elevated SDC1. DISCUSSION: These findings suggest serum SDC1 as a promising novel biomarker for early blood-based diagnosis of pancreatic cancer.

Dexmedetomidine suppresses serum syndecan-1 elevation and improves survival in a rat hemorrhagic shock model.

Hemorrhagic shock causes vascular endothelial glycocalyx (EGCX) damage and systemic inflammation. Dexmedetomidine (DEX) has anti-inflammatory and EGCX-protective effects, but its effect on hemorrhagic shock has not been investigated. Therefore, we investigated whether DEX reduces inflammation and protects EGCX during hemorrhagic shock. Anesthetized Sprague-Dawley rats were randomly assigned to five groups (n=7 per group): no shock (SHAM), hemorrhagic shock (HS), hemorrhagic shock with DEX (HS+DEX), hemorrhagic shock with DEX and the α7 nicotinic type acetylcholine receptor antagonist methyllycaconitine citrate (HS+DEX/MLA), and hemorrhagic shock with MLA (HS+MLA). HS was induced by shedding blood to a mean blood pressure of 25-30 mmHg, which was maintained for 30 min, after which rats were resuscitated with Ringer's lactate solution at three times the bleeding volume. The survival rate was assessed up to 3 h after the start of fluid resuscitation. Serum tumor necrosis factor-alpha (TNF-α) and syndecan-1 concentrations, and wet-to-dry ratio of the heart were measured 90 min after the start of fluid resuscitation. The survival rate after 3 h was significantly higher in the HS+DEX group than in the HS group. Serum TNF-α and syndecan-1 concentrations, and the wet-to-dry ratio of heart were elevated by HS, but significantly decreased by DEX. These effects were antagonized by MLA. DEX suppressed the inflammatory response and serum syndecan-1 elevation, and prolonged survival in rats with HS.

Association between plasma glycocalyx component levels and poor prognosis in severe influenza type A (H1N1).

Influenza A virus infection causes a series of diseases, but the factors associated with disease severity are not fully understood. Disruption of the endothelial glycocalyx contributes to acute lung injury in sepsis, but has not been well studied in H1N1 influenza. We aim to determine whether the plasma glycocalyx components levels are predictive of disease severity in H1N1 influenza. This prospective observational study included 53 patients with influenza A (H1N1) during the influenza season, and 30 healthy controls in our hospital. Patients were grouped by severity and survival. We collected clinical data and blood samples at admission. Inflammatory factors (tumor necrosis factor-α, interleukin-6, interleukin-10) and endothelial glycocalyx components (syndecan-1, hyaluronan, heparan sulfate) were measured. The plasma levels of syndecan-1, hyaluronan, and heparan sulfate were significantly higher in patients with severe influenza A (H1N1) than in mild cases. Syndecan-1 and hyaluronan were positively correlated with disease severity, which was indicated by the APACHE II and SOFA scores and lactate levels, and negatively correlated with albumin levels. At a cutoff point ≥ 173.9 ng/mL, syndecan-1 had a 81.3% sensitivity and 70.3% specificity for predicting of 28-day mortality. Kaplan-Meier analysis demonstrated a strong association between syndecan-1 levels and 28-day mortality (log-rank 11.04, P = 0.001). Elevated plasma levels of syndecan-1 has a potential role in systemic organ dysfunction and may be indicative of disease severity in patients with influenza A (H1N1).

Suppressing Syndecan-1 Shedding to Protect Against Renal Ischemia/Reperfusion Injury by Maintaining Polarity of Tubular Epithelial Cells.

ABSTRACT: Syndecan-1 (SDC-1), a type of heparan sulfate proteoglycan on the surface of epithelial cells, is involved in maintaining cell morphology. Loss of cell polarity constitutes the early stage of ischemic acute kidney injury (AKI). This study investigated the role of SDC-1 shedding in I/R-induced AKI and the underlying mechanisms. Levels of the shed SDC-1 in the serum were measured with ELISA 12 and 24 h after reperfusion in renal I/R model mice. Na+/K+-ATPase-α1 expression was evaluated using western blotting in vivo and immunofluorescence in hypoxia/reoxygenation (H/R) cysts. Renal tubular epithelial cell apoptosis was measured using TUNEL in vivo and flow cytometry in vitro. Furthermore, plasma syndecan-1 (pSDC-1) levels were measured in patients at the time of anesthesia resuscitation after cardiac surgery. We found that shed SDC-1 levels increased and Na+/K+-ATPase-α1 expression decreased after H/R in the three-dimensional (3D) tubular model, and this state was exacerbated with extended period of hypoxia. After the inhibition of SDC-1 shedding by GM6001, SDC-1 and Na+/K+-ATPase-α1 expression was restored, while H/R-induced apoptosis was decreased. In vivo, SDC-1 shedding was induced by renal I/R and was accompanied with a loss of renal tubular epithelial cell polarity and increased apoptosis. GM6001 pretreatment protected against I/R injury by alleviating the disruption of cell polarity and apoptosis. pSDC-1 levels were significantly higher in AKI patients than in non-AKI patients. ROC curve showed that the accuracy of pSDC-1 for AKI prediction was 0.769. In conclusion, inhibition of I/R-induced SDC-1 shedding could contribute to renal protection by restoring the loss of cell polarity and alleviating apoptosis in tubular epithelial cells.

Shock-Induced Endothelial Dysfunction is Present in Patients With Occult Hypoperfusion After Trauma.

BACKGROUND: Shock-induced endothelial dysfunction, evidenced by elevated soluble thrombomodulin (sTM) and syndecan-1 (Syn-1), is associated with poor outcomes after trauma. The association of endothelial dysfunction and overt shock has been demonstrated; it is unknown if hypoperfusion in the setting of normal vital signs (occult hypoperfusion [OH]) is associated with endothelial dysfunction. We hypothesized that sTM and Syn-1 would be elevated in patients with OH when compared to patients with normal perfusion. METHODS: A single-center study of patients requiring highest-level trauma activation (2012-2016) was performed. Trauma bay arrival plasma Syn-1 and sTM were measured by enzyme-linked immunosorbent assay. Shock was defined as systolic blood pressure (SBP) <90 mm Hg or heart rate (HR) ≥120 bpm. OH was defined as SBP ≥ 90, HR < 120, and base excess (BE) ≤-3. Normal perfusion was assigned to all others. Univariate and multivariable analyses were performed. RESULTS: Of 520 patients, 35% presented with OH and 26% with shock. Demographics were similar between groups. Patients with normal perfusion had the lowest Syn-1 and sTM, while patients with OH and shock had elevated levels. OH was associated with increased sTM by 0.97 ng/mL (95% CI 0.39-1.57, p = 0.001) and Syn-1 by 14.3 ng/mL (95% CI -1.5 to 30.2, p = 0.08). Furthermore, shock was associated with increased sTM by 0.64 (95% CI 0.02-1.30, p = 0.04) and with increased Syn-1 by 23.6 ng/mL (95% CI 6.2-41.1, p = 0.008). CONCLUSIONS: Arrival OH was associated with elevated sTM and Syn-1, indicating endothelial dysfunction. Treatments aiming to stabilize the endothelium may be beneficial for injured patients with evidence of hypoperfusion, regardless of vital signs.

Kawasaki disease and increased cardiovascular risk: Is there a link to circulating glycocalyx biomarkers?

AIMS: Kawasaki disease (KD) is an acute systemic vasculitis with possible long-term impact of general cardio-vascular health. An endothelial glycocalyx disorder during the disease's acute phase might predispose to long-term vascular anomalies leading to endothelial dysfunction and atherosclerosis. To investigate any association between increased cardiovascular risk and endothelial glycocalyx, we assessed circulating glycocalyx components in patients with a KD history, and analysed their association with acute-phase clinical features and more importantly, with patients' current cardiovascular risk factors. METHODS: This prospective observational cohort study included 51 subjects: 31 patients with a history of KD, and 20 healthy subjects matched for age and sex. We analysed serum syndecan-1 and hyaluronan via ELISA. We assessed features reported during the acute phase of KD such as blood counts, C-reactive protein (CRP) levels and coronary artery aneurysms (CAA), and their current blood pressure and lipid markers in relation to measured glycocalyx components. RESULTS: Our multivariate analysis revealed that hyaluronan and syndecan-1 levels were not associated with KD. However, the latter exhibited a significant association with acute-phase blood count alterations in patients with KD. Furthermore, significant interactions of hyaluronan and syndecan-1 with certain cardiovascular risk factors like blood lipids and blood pressure were only present in KD patients. CONCLUSION: Vasculitis during KD's acute phase might predispose to a long-term endothelial glycocalyx alteration, influenced by other factors having a vascular impact such as blood pressure and circulating lipids. CLINICAL TRIAL REGISTRATION: German Clinical Trials Register on 25th February 2016, DRKS00010071 https://www.drks.de/drks_web/.

Syndecan-1, an indicator of endothelial glycocalyx degradation, predicts outcome of patients admitted to an ICU with COVID-19.

BACKGROUND: We investigated the feasibility of two biomarkers of endothelial damage (Syndecan-1 and thrombomodulin) in coronavirus disease 2019 (COVID-19), and their association with inflammation, coagulopathy, and mortality. METHODS: The records of 49 COVID-19 patients who were admitted to an intensive care unit (ICU) in Wuhan, China between February and April 2020 were examined. Demographic, clinical, and laboratory data, and outcomes were compared between survivors and non-survivors COVID-19 patients, and between patients with high and low serum Syndecan-1 levels. The dynamics of serum Syndecan-1 levels were also analyzed. RESULTS: The levels of Syndecan-1 were significantly higher in non-survivor group compared with survivor group (median 1031.4 versus 504.0 ng/mL, P = 0.002), and the levels of thrombomodulin were not significantly different between these two groups (median 4534.0 versus 3780.0 ng/mL, P = 0.070). Kaplan-Meier survival analysis showed that the group with high Syndecan-1 levels had worse overall survival (log-rank test: P = 0.023). Patients with high Syndecan-1 levels also had significantly higher levels of thrombomodulin, interleukin-6, and tumor necrosis factor-α. Data on the dynamics of Syndecan-1 levels indicated much greater variations in non-survivors than survivors. CONCLUSIONS: COVID-19 patients with high levels of Syndecan-1 develop more serious endothelial damage and inflammatory reactions, and have increased mortality. Syndecan-1 has potential for use as a marker for progression or severity of COVID-19. Protecting the glycocalyx from destruction is a potential treatment for COVID-19.

Serum syndecan-1 concentration in hospitalized patients with heart failure may predict readmission-free survival.

Syndecan-1 is found in the endothelial glycocalyx and is released into the bloodstream during stressed conditions, including severe diseases such as acute kidney injury, chronic kidney disease, and cardiovascular disease. This study investigated the prognostic value of serum syndecan-1 concentration in patients with heart failure upon admission. Serum syndecan-1 concentration was analyzed in 152 patients who were hospitalized for worsening heart failure from September 2017 to June 2018. The primary outcome of the study was readmission-free survival, defined as the time from the first admission to readmission for worsened heart failure or death from any cause, which was assessed at 30 months after discharge from the hospital. The secondary outcome of the study was survival time. Blood samples and echocardiogram data were analyzed. Univariate and multivariable time-dependent Cox regression analyses adjusted for age, creatinine levels, and use of antibiotics were conducted. The serum syndecan-1 concentration was significantly associated with readmission-free survival. Subsequently, the syndecan-1 concentration may have gradually decreased with treatment. The administration of human atrial natriuretic peptide and antibiotics may have modified the relationship between readmission-free survival and serum syndecan-1 concentration (p = 0.01 and 0.008, respectively). Serum syndecan-1 concentrations, which may indicate injury to the endothelial glycocalyx, predict readmission-free survival in patients with heart failure.

Indications of Persistent Glycocalyx Damage in Convalescent COVID-19 Patients: A Prospective Multicenter Study and Hypothesis.

The COVID-19 pandemic is caused by the SARS CoV-2 virus and can lead to severe lung damage and hyperinflammation. In the context of COVID-19 infection, inflammation-induced degradation of the glycocalyx layer in endothelial cells has been demonstrated. Syndecan-1 (SDC-1) is an established parameter for measuring glycocalyx injury. This prospective, multicenter, observational, cross-sectional study analyzed SDC-1 levels in 24 convalescent patients that had been infected with SARS-CoV-2 with mild disease course without need of hospitalization. We included 13 age-matched healthy individuals and 10 age-matched hospitalized COVID-19 patients with acute mild disease course as controls. In convalescent COVID-19 patients, significantly elevated SDC-1 levels were detected after a median of 88 days after symptom onset compared to healthy controls, whereas no difference was found when compared to SDC-1 levels of hospitalized patients undergoing acute disease. This study is the first to demonstrate signs of endothelial damage in non-pre-diseased, convalescent COVID-19 patients after mild disease progression without hospitalization. The data are consistent with studies showing evidence of persistent endothelial damage after severe or critical disease progression. Further work to investigate endothelial damage in convalescent COVID-19 patients should follow.

Circulating CD138 enhances disease progression by augmenting autoreactive antibody production in a mouse model of systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a progressive autoimmune disease characterized by high levels of antibodies directed against nuclear antigens. Elevated serum CD138, a heparan sulfate-bearing proteoglycan, correlates with increased disease activity in patients with SLE, but the contribution of CD138 to lupus disease is not known. Corroborating patient data, we detected an increase in serum CD138 in MRL/MpJ-Faslpr/J (MRL/Lpr) mice (a model for SLE disease) parallel to disease activity. Although T-cell receptor ß (TCRß)+CD138+ T cells typically expand in MRL/Lpr mice as the disease progresses, surprisingly, TCRß+CD138- cells were the primary source of circulating CD138, as the transfer of TCRß+CD138- cells, but not TCRß+CD138+ cells, to young MRL/Lpr mice resulted in higher serum CD138 in the recipients. We found that trypsin was able to cleave CD138 from TCRß+CD138+ cells, and that trypsin was highly expressed in TCRß+CD138- cells. Moreover, trypsin inhibitors, the "defined trypsin inhibitor" and leupeptin, increased CD138 expression on TCRß+CD138- cells, suggesting a contribution of cleaved CD138 to the increase in blood CD138 levels. Furthermore, soluble CD138 was able to bind "a proliferation-inducing ligand" (APRIL) and enhance APRIL-mediated plasma cell generation and autoreactive antibody production through the phosphorylation of extracellular signal-regulated kinase in B cells. The APRIL receptor "transmembrane activator, calcium modulator, and cyclophilin ligand interactor" was involved in the enhancement of APRIL activity by CD138, as the synergistic effect of APRIL and CD138 was ablated in transmembrane activator, calcium modulator, and cyclophilin ligand interactor-deficient B cells. These findings indicate a regulatory role for soluble CD138 in B-cell differentiation and autoreactive antibody production in SLE disease.