Endothelial protein C receptor plasma levels increase in chronic liver disease, while thrombomodulin plasma levels increase only in hepatocellular carcinoma

High plasma soluble thrombomodulin levels indicated poor prognosis of decompensated liver cirrhosis: a prospective cohort study

OBJECTIVE

Hepatic sinusoidal endothelial injury is a prominent characteristic of liver cirrhosis. We determined plasma soluble thrombomodulin (sTM) levels in cirrhosis patients to evaluate the relationship between vascular injury and long-term prognosis.

METHODS

A prospective single-center study was performed. The participants were followed up for every 6 months or until death or transplantation. A chemiluminescent enzyme immunoassay was used to establish a baseline sTM.

RESULTS

Among the 219 patients with decompensated liver cirrhosis, 53.42% were caused by hepatitis B and hepatitis C. Plasma sTM levels were much higher in cirrhosis than in healthy controls and increased parallel with Child-Pugh classification ( P < 0.01) and the amount of ascites ( P = 0.04). After adjusting for sex, age, international normalized ratio, bilirubin, and other potential factors, multivariate Cox regression revealed that per TU/ml elevation of plasma sTM causes an increase of 8% in mortality, and per-SD elevation of thrombomodulin causes a 53% increase in mortality. As the mortality rates in low (5.90-12.60 TU/ml) and medium (12.70-18.00 TU/ml) sTM levels were similar, so we chose the cutoff of 18.00 TU/ml to divide into two groups, and K-M analysis indicated that patients with sTM >18.0 TU/ml demonstrated an additional 2.01 times death risk (95% CI, 1.13-7.93; P = 0.01) than those with sTM ≤18.0 TU/ml.

CONCLUSION

Plasma sTM in cirrhosis was significantly increased in parallel with the severity of liver dysfunction. sTM elevation than 18 TU/ml indicated a poor prognosis of decompensated liver cirrhosis.

Fibrinolytic markers could be useful predictors of severity in patients with pulmonary arterial hypertension: a retrospective study

Background

The severity of pulmonary arterial hypertension (PAH) is classified based on mean pulmonary artery pressure (mPAP) levels. However, other markers have not been elucidated. Fibrinolytic markers, such as total plasminogen activator inhibitor-1 (tPAI-1) and thrombomodulin (TM), are known to reflect arterial endothelial function. However, the relationship between serum tPAI-1, TM and pulmonary circulation has not been completely determined.

Methods

This study included 100 consecutive patients (38 men), with a mean age of 68.9 ± 12.0 years, with cardiac diseases who underwent right heart catheterization. Serum coagulation and fibrinolytic marker levels were measured.

Results

The average mPAP value was 25.1 ± 13.1 mmHg for all patients. The mPAP levels revealed a significant positive correlation with serum tPAI-1 (ρ = 0.24, p = 0.042) and uric acid (ρ = 0.29, p = 0.0031) levels. In the group with mPAP levels less than 25 mmHg (n = 58, ave. 17.3 ± 4.3 mmHg), mPAP levels showed a significant positive correlation with serum tPA-1 (ρ = 0.34, p = 0.034) and TM (ρ = 0.34, p = 0.043) values. The mean tPAI-1 (29.8 ± 23.3 ng/ml, p = 0.047) and uric acid (5.7 ± 1.8 mg/dl, p = 0.026) levels were significantly less in those with lower mPAP levels. A multivariate analysis revealed that tPAI-1 alone was a significant independent characteristic marker of PAH (odds ratio 1.02, 95%CI 1.000–1.036, p = 0.034).

Conclusions

These results indicate that serum tPAI-1 and TM may be useful predictors of severity, similar to mPAP in patients with PAH. They could be beneficial in predicting PAH among patients in the early stage of the disease.

Could protein content of Urinary Extracellular Vesicles be useful to detect Cirrhosis in Alcoholic Liver Disease?

Alcohol abuse has a high impact on the mortality and morbidity related to a great number of diseases and is responsible for the development of alcoholic liver disease (ALD). It remains challenging to detect and evaluate its severity, which is crucial for prognosis. In this work, we studied if urinary EVs (uEVs) could serve in diagnose and evaluate cirrhosis in ALD. To this purpose, uEVs characterization by cryo-electron microscopy (Cryo-EM), Nanoparticle Tracking Analysis (NTA) and Western blotting (WB) was performed in a cohort of 21 controls and 21 cirrhotic patients. Then, proteomics of uEVs was carried out in a second cohort of 6 controls and 8 patients in order to identify new putative biomarkers for cirrhosis in ALD. Interestingly, uEVs concentration, size and protein composition were altered in cirrhotic patients. From a total of 1304 proteins identified in uEVs, 90 of them were found to be altered in cirrhotic patients. The results suggest that uEVs could be considered as a tool and a supplier of new biomarkers for cirrhosis in ALD, whose application would be especially relevant in chronic patients. Yet, further research is necessary to obtain more relevant result in clinical terms.

Cell painting with an engineered EPCR to augment the protein C system

The protein C (PC) system conveys beneficial anticoagulant and cytoprotective effects in numerous in vivo disease models. The endothelial protein C receptor (EPCR) plays a central role in these pathways as cofactor for PC activation and by enhancing activated protein C (APC)-mediated protease-activated receptor (PAR) activation. During inflammatory disease, expression of EPCR on cell membranes is often diminished thereby limiting PC activation and APC's effects on cells. Here a caveolae-targeting glycosylphosphatidylinositol (GPI)-anchored EPCR (EPCR-GPI) was engineered to restore EPCR's bioavailability via "cell painting." The painting efficiency of EPCR-GPI on EPCR-depleted endothelial cells was time- and dose-dependent. The EPCR-GPI bioavailability after painting was long lasting since EPCR surface levels reached 400 % of wild-type cells after 2 hours and remained > 200 % for 24 hours. EPCR-GPI painting conveyed APC binding to EPCR-depleted endothelial cells where EPCR was lost due to shedding or shRNA. EPCR painting normalised PC activation on EPCR-depleted cells indicating that EPCR-GPI is functional active on painted cells. Caveolin-1 lipid rafts were enriched in EPCR after painting due to the GPI-anchor targeting caveolae. Accordingly, EPCR painting supported PAR1 and PAR3 cleavage by APC and augmented PAR1-dependent Akt phosphorylation by APC. Thus, EPCR-GPI painting achieved physiological relevant surface levels on endothelial cells, restored APC binding to EPCR-depleted cells, supported PC activation, and enhanced APC-mediated PAR cleavage and cytoprotective signalling. Therefore, EPCR-GPI provides a novel tool to restore the bioavailability and functionality of EPCR on EPCR- depleted and -deficient cells.

Analysis of endothelial protein C receptor functionality on living cells'

Activated protein C (APC) is a major control system of blood coagulation. APC prevents coagulation pathway by degrading Va and VIIIa plasma's coagulation factors. Protein C activation requires its binding to specific endothelial cell receptor (EPCR). APC binding to EPCR also activates a wide range of defense mechanisms (anti-inflammatory, antiapoptosis...). EPCR expression by cells can be detected by various methods, including immunoanalysis and molecular biology. However, no assays evaluate its functionality. A method, inspired of a standard fibrinoformation time assay, was developed to estimate EPCR ability to bind APC on living cell surface in vitro. Endothelial cells were incubated with APC and fibrinoformation on cells was followed by spectrophotometry (plasma absorbance increases with fibrin polymerization). Membrane-bound EPCR retain APC, thus prolonging fibrinoformation time in a dose-dependent manner. Control was realized with EPCR-negative cells. This new method can be used on any cell type to study the expression of other coagulation receptors.

Decreased plasma soluble thrombomodulin levels as a risk factor for pulmonary thromboembolism

OBJECTIVE

To observe the changes of the plasma soluble thrombomodulin (sTM) concentrations in patients with pulmonary thromboembolism (PTE) and assess the association between plasma sTM concentration and the risk of PTE.

PATIENTS AND METHODS

We measured plasma concentrations of sTM, protein C (PC) and protein S (PS) and examined the association between those plasma markers and the risk of PTE in 72 selected PTE patients and 70 controls.

RESULTS

Significant difference was identified in plasma sTM level between overall PTE patients and controls. Female PTE patients had statistically lower sTM concentrations than male patients. A positive linear correlation was found between plasma sTM concentration and age in female patients. Decreased plasma sTM concentration was associated with a continuously and progressively increased risk for PTE in women. The concentrations of plasma PC and PS did not differ between groups and no significant quantitative association was identified between the risk of PTE and the levels of plasma PC or PS.

CONCLUSION

Decreased plasma sTM concentration is associated with an increased risk of PTE in women.