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Objectives To investigate whether circulating endothelial protein C receptor (EPCR) is associated with disease activity and inflammatory markers in rheumatoid arthritis. Methods Thirty-eight RA patients and 21 healthy controls (HC) were recruited via the A3BC biobank. Peripheral blood mononuclear cells and plasma were isolated from the blood of these participants. Plasma soluble (s)EPCR, IL-6, IL-17 and sCD14 were measured by enzyme-linked immunosorbent assay, cell membrane-associated (m)EPCR by flow cytometry; EPCR gene H3 single nucleotide polymorphism (SNP), which contributes to high plasma sEPCR levels, by PCR and DNA sequencing. Data were analysed using FlowJo10 and GraphPad Prism 10. Results RA patients had higher levels of mEPCR on T cells and plasma sEPCR compared with HC. No difference in the EPCR gene H3 SNP G genotype frequency was found between RA and HC. This SNP was significantly correlated with higher sEPCR levels in HC but not in RA patients. In RA, plasma sEPCR levels were positively correlated with IL-6, IL-17, sCD14, anti-CCP and rheumatoid factor. In contrast, mEPCR levels on T cells and natural killer cells (NK) were inversely associated with disease activity measures including 28/66 swollen joint count, 28/68 tender joint count and/or DAS28-CRP/ESR scores, and positively correlated with EPCR gene H3 SNP, which was also correlated with lower disease activity measures in RA. Conclusion Our findings suggest that EPCR may play an important role in RA, with plasma sEPCR being potentially associated with inflammatory markers and mEPCR and the EPCR gene H3 SNP possibly related to disease activity measures. [ABSTRACT FROM AUTHOR]

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of pathogenic antiphospholipid antibodies (aPL). Since approximately 30 years ago, lipid-binding aPL, which do not require a protein cofactor, have been regarded as irrelevant for APS pathogenesis even though anticardiolipin are a diagnostic criterion of APS. In this review, we will summarize the available evidence from in vitro studies, animal models, and epidemiologic studies, which suggest that this concept is no longer tenable. Accordingly, we will only briefly touch on the role of other aPL in APS. This topic has been amply reviewed in detail elsewhere. We will discuss the consequences for laboratory diagnostics and future research required to resolve open questions related to the pathogenic role of different aPL specificities. [ABSTRACT FROM AUTHOR]

Même si ces dernières années la définition du syndrome des antiphospholipides (SAPL) n'a pas subi de changements majeurs, certaines connaissances ont évolué au cours du temps. Dans cet article, nous présenterons les nouveautés en termes de critères de classification, physiopathologie, évaluation du risque prothrombotique, cibles antigéniques et enfin traitements potentiels. Even if in recent years the definition of anti-phospholipid syndrome (APS) has not undergone major changes, some knowledges have evolved over time. In this article, we will present the new developments in terms of classification criteria, pathophysiology, assessment of prothrombotic risk, antigenic targets and finally potential treatments. [ABSTRACT FROM AUTHOR]

Endothelial Protein C Receptor (EPCR) is a key regulator of the activated protein C anti-coagulation pathway due to its role in the binding and activation of this protein. EPCR also binds to other ligands such as Factor VII and X, γδ T-cells, plasmodium falciparum erythrocyte membrane protein 1, and Secretory group V Phospholipases A2, facilitating ligand-specific functions. The functions of EPCR can also be regulated by soluble (s)EPCR that competes for the binding sites of membrane-bound (m)EPCR. sEPCR is created when mEPCR is shed from the cell surface. The propensity of shedding alters depending on the genetic haplotype of the EPCR gene that an individual may possess. EPCR plays an active role in normal homeostasis, anti-coagulation pathways, inflammation, and cell stemness. Due to these properties, EPCR is considered a potential effector/mediator of inflammatory diseases. Rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus are autoimmune/inflammatory conditions that are associated with elevated EPCR levels and disease activity, potentially driven by EPCR. This review highlights the functions of EPCR and its contribution to rheumatic diseases. [ABSTRACT FROM AUTHOR]

Objectives Endothelial protein C receptor (EPCR) is highly expressed in synovial tissues of patients with RA, but the function of this receptor remains unknown in RA. This study investigated the effect of EPCR on the onset and development of inflammatory arthritis and its underlying mechanisms. Methods CIA was induced in EPCR gene knockout (KO) and matched wild-type (WT) mice. The onset and development of arthritis was monitored clinically and histologically. T cells, dendritic cells (DCs), EPCR and cytokines from EPCR KO and WT mice, RA patients and healthy controls (HCs) were detected by flow cytometry and ELISA. Results EPCR KO mice displayed >40% lower arthritis incidence and 50% less disease severity than WT mice. EPCR KO mice also had significantly fewer Th1/Th17 cells in synovial tissues with more DCs in circulation. Lymph nodes and synovial CD4 T cells from EPCR KO mice expressed fewer chemokine receptors CXCR3, CXCR5 and CCR6 than WT mice. In vitro , EPCR KO spleen cells contained fewer Th1 and more Th2 and Th17 cells than WT and, in concordance, blocking EPCR in WT cells stimulated Th2 and Th17 cells. DCs generated from EPCR KO bone marrow were less mature and produced less MMP-9. Circulating T cells from RA patients expressed higher levels of EPCR than HC cells; blocking EPCR stimulated Th2 and Treg cells in vitro. Conclusion Deficiency of EPCR ameliorates arthritis in CIA via inhibition of the activation and migration of pathogenic Th cells and DCs. Targeting EPCR may constitute a novel strategy for future RA treatment. [ABSTRACT FROM AUTHOR]

BackgroundThe rs867186 single-nucleotide polymorphism in the PROCR gene (g.6936A > G, c.4600A > G) results in a serine-to-glycine substitution at codon 219 of endothelial protein C receptor (EPCR). We performed a case–control study followed by an updated meta-analysis of the association between this polymorphism and the risk of venous thromboembolism (VTE).Objective and methodsWe enrolled 263 VTE patients and 320 unrelated healthy controls for the case–control study. The total number of cases and controls for the meta-analysis were 5,768 and 30,017, respectively. A new online MetaGenyo Statistical Analysis System software was used to perform the current meta-analysis. Furthermore, a reproducibility study was conducted to validate our results.ResultsAmong well-defined thrombosis risk factors, Factor V Leiden was more frequent in the VTE group (p A polymorphism between the two groups. There was no difference in the mutation frequency of Factor V Leiden and prothrombin 20210G>A between cases with and without provoking factors and cases with and without VTE recurrence. The rs867186 “G” carriership did not influence the risk of VTE [odds ratio (OR) 1.339; 95% confidence interval (CI): 0.904–1.984] in our study. No significant differences could be demonstrated among the rs867186 genotype frequencies between VTE cases with and without provoking factors (p = 0.430). PROCR rs867186 was associated with an OR of 1.72 (95% CI: 0.95–3.13, p = 0.075) in terms of VTE recurrence. In the meta-analysis, a significant association was found between EPCR Ser219Gly polymorphism and VTE under the dominant model (OR = 1.27, 95% CI: 1.11–1.46, p = 0.0006), the recessive model (OR = 1.60, 95% CI: 1.26–2.04, p = 0.0001), the GG vs. AA contrast model (OR = 1.64, 95% CI: 1.28–2.09, p = 0.0001), and the GA vs. AA contrast model (OR = 1.24, 95% CI: 1.08–1.43, p = 0.002).ConclusionThe rs867186 was not associated with the first VTE risk in our case–control study; however, a tendency to VTE recurrence was observed. Based on the results of our reproducibility study, MetaGenyo is acceptable for meta-analysis in case of genetic epidemiology studies. Although the risk conferred by the rs867186 is mild in all meta-analyses, including ours, identifying patients carrying the minor allele might have an impact on personalized VTE risk assessment, risk-score calculation, and patient management.

ABSTRACT Antibody responses to variant surface antigens (VSAs) produced by the malaria parasite Plasmodium falciparum may contribute to age-related natural immunity to severe malaria. One VSA family, P. falciparum erythrocyte membrane protein-1 (PfEMP1), includes a subset of proteins that binds endothelial protein C receptor (EPCR) in human hosts and potentially disrupts the regulation of inflammatory responses, which may lead to the development of severe malaria. We probed peptide microarrays containing segments spanning five PfEMP1 EPCR-binding domain variants with sera from 10 Malian adults and 10 children to determine the differences between adult and pediatric immune responses. We defined serorecognized peptides and amino acid residues as those that elicited a significantly higher antibody response than malaria-naïve controls. We aimed to identify regions consistently serorecognized among adults but not among children across PfEMP1 variants, potentially indicating regions that drive the development of immunity to severe malaria. Adult sera consistently demonstrated broader and more intense serologic responses to constitutive PfEMP1 peptides than pediatric sera, including peptides in EPCR-binding domains. Both adults and children serorecognized a significantly higher proportion of EPCR-binding peptides than peptides that do not directly participate in receptor binding, indicating a preferential development of serologic responses at functional residues. Over the course of a single malaria transmission season, pediatric serological responses increased between the start and the peak of the season, but waned as the transmission season ended. IMPORTANCE Severe malaria and death related to malaria disproportionately affect sub-Saharan children under 5 years of age, commonly manifesting as cerebral malaria and/or severe malarial anemia. In contrast, adults in malaria-endemic regions tend to experience asymptomatic or mild disease. Our findings indicate that natural immunity to malaria targets specific regions within the EPCR-binding domain, particularly peptides containing EPCR-binding residues. Epitopes containing these residues may be promising targets for vaccines or therapeutics directed against severe malaria. Our approach provides insight into the development of natural immunity to a binding target linked to severe malaria by characterizing an “adult-like” response as recognizing a proportion of epitopes within the PfEMP1 protein, particularly regions that mediate EPCR binding. This “adult-like” response likely requires multiple years of malaria exposure, as increases in pediatric serologic response over a single malaria transmission season do not appear significant.

Postmortem neuropathology shows clear regional differences in many brain diseases. For example, brains from cerebral malaria (CM) patients show more hemorrhagic punctae in the brain's white matter (WM) than grey matter (GM). The underlying reason for these differential pathologies is unknown. Here, we assessed the effect of the vascular microenvironment on brain endothelial phenotype, focusing endothelial protein C receptor (EPCR). We demonstrate that the basal level of EPCR expression in cerebral microvessels is heterogeneous in the WM compared to the GM. We used in vitro brain endothelial cell cultures and showed that the upregulation of EPCR expression was associated with exposure to oligodendrocyte conditioned media (OCM) compared to astrocyte conditioned media (ACM). Our findings shed light on the origin of the heterogeneity of molecular phenotypes at the microvascular level and might help better understand the variation in pathology seen in CM and other neuropathologies associated with vasculature in various brain regions. [ABSTRACT FROM AUTHOR]

Postmortem neuropathology shows clear regional differences in many brain diseases. For example, brains from cerebral malaria (CM) patients show more hemorrhagic punctae in the brain’s white matter (WM) than grey matter (GM). The underlying reason for these differential pathologies is unknown. Here, we assessed the effect of the vascular microenvironment on brain endothelial phenotype, focusing endothelial protein C receptor (EPCR). We demonstrate that the basal level of EPCR expression in cerebral microvessels is heterogeneous in the WM compared to the GM. We used in vitro brain endothelial cell cultures and showed that the upregulation of EPCR expression was associated with exposure to oligodendrocyte conditioned media (OCM) compared to astrocyte conditioned media (ACM). Our findings shed light on the origin of the heterogeneity of molecular phenotypes at the microvascular level and might help better understand the variation in pathology seen in CM and other neuropathologies associated with vasculature in various brain regions.

Background: Hematopoietic stem cell (HSC) transplantation is considered a possible treatment option capable of curing various diseases. The aim of this study was the co-culturing of mesenchymal stem cell (MSC) spheres with HSCs under hypoxic condition to enhance the proliferation, self-renewal, stemness, and homing capacities of HSCs. Methods and results: HSCs were expanded after being subjected to different conditions including cytokines without feeder (Cyto), co-culturing with adherent MSCs (MSC), co-culturing with adherent MSCs + hypoxia (MSC + Hyp), co-culturing with MSCs spheres (Sph-MSC), co-culturing with MSCs spheres + hypoxia (Sph-MSC + Hyp), co-culturing with MSC spheres + cytokines (Sph-MSC + Cyto). After 10 days, total nucleated cell (TNC) and CD34+/CD38− cell counts, colony-forming unit assay (CFU), long-term culture initiating cell (LTC-IC), the expression of endothelial protein C receptor (EPCR), nucleostemin (NS), nuclear factor I/X (Nfix) CXCR4, and VLA-4 were evaluated. The TNC, CD34+/CD38− cell count, CFU, and LTC-IC were higher in the Sph-MSC + Hyp and Sph-MSC + Cyto groups as compared with those of the MSC + Hyp group (P < 0.001). The expanded HSCs co-cultured with MSC spheres in combination with hypoxia expressed more EPCR, CXCR4, VLA-4, NS, and Nfix mRNA. The protein expression was also more up-regulated in the Sph-MSC + Cyto and Sph-MSC + Hyp groups. Conclusion: Co-culturing HSCs with MSC spheres under hypoxic condition not only leads to higher cellular yield but also increases the expression of self-renewal and homing genes. Therefore, we suggest this approach as a simple and non-expensive strategy that might improve the transplantation efficiency of HSCs. [ABSTRACT FROM AUTHOR]

Cytoadhesion of Plasmodium falciparum -infected red blood cells is a virulence determinant associated with microvascular obstruction and organ complications. The gastrointestinal tract is a major site of sequestration in fatal cerebral malaria cases and kidney complications are common in severe malaria, but parasite interactions with these microvascular sites are poorly characterized. To study parasite tropism for different microvascular sites, we investigated binding of parasite lines to primary human microvascular endothelial cells from intestine (HIMEC) and peritubular kidney (HKMEC) sites. Of the three major host receptors for P. falciparum , CD36 had low or negligible expression; endothelial protein C receptor (EPCR) had the broadest constitutive expression; and intercellular adhesion molecule 1 (ICAM-1) was weakly expressed on resting cells and was strongly upregulated by TNF-α on primary endothelial cells from the brain, intestine, and peritubular kidney sites. By studying parasite lines expressing var genes linked to severe malaria, we provide evidence that both the DC8 and Group A EPCR-binding subsets of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family encodes binding affinity for brain, intestinal, and peritubular kidney endothelial cells, and that DC8 parasite adhesion was partially dependent on EPCR. Collectively, these findings raise the possibility of a brain-gut-kidney binding axis contributing to multi-organ complications in severe malaria. [ABSTRACT FROM AUTHOR]

Cytoadhesion of Plasmodium falciparum-infected red blood cells is a virulence determinant associated with microvascular obstruction and organ complications. The gastrointestinal tract is a major site of sequestration in fatal cerebral malaria cases and kidney complications are common in severe malaria, but parasite interactions with these microvascular sites are poorly characterized. To study parasite tropism for different microvascular sites, we investigated binding of parasite lines to primary human microvascular endothelial cells from intestine (HIMEC) and peritubular kidney (HKMEC) sites. Of the three major host receptors for P. falciparum, CD36 had low or negligible expression; endothelial protein C receptor (EPCR) had the broadest constitutive expression; and intercellular adhesion molecule 1 (ICAM-1) was weakly expressed on resting cells and was strongly upregulated by TNF-α on primary endothelial cells from the brain, intestine, and peritubular kidney sites. By studying parasite lines expressing var genes linked to severe malaria, we provide evidence that both the DC8 and Group A EPCR-binding subsets of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family encodes binding affinity for brain, intestinal, and peritubular kidney endothelial cells, and that DC8 parasite adhesion was partially dependent on EPCR. Collectively, these findings raise the possibility of a brain-gut-kidney binding axis contributing to multi-organ complications in severe malaria.

It is not yet clear whether cellular junctions between splenic sinus endothelial cells are open or closed. In order to clarify this, immunolocalization of thrombomodulin (TM), endothelial protein C receptor (EPCR), protease-activated receptor 1 (PAR1), sphingosine 1-phosphate receptor 1 (S1P1), β-catenin phosphorylated at Try142 (β-catenin Y142) and β-catenin phosphorylated at Try654 (β-catenin Y654), which are related proteins that regulate dissociation and association of the adherens junctions of endothelial cells, are examined in rats using laser microscopy and electron microscopy. TM, EPCR, PAR1 and S1P1 were colocalized in the entire circumference of the endothelial cells, as well as in the caveolar membranes and junctional membranes of adjacent endothelial cells. These molecules may protect the adherens junctions of the endothelial cells. On the other hand, β-catenin Y142 and β-catenin Y 654 colocalized with α-catenin and β-catenin, respectively and in addition, β-catenin Y142 and β-catenin Y 654 were localized in the vicinity of the adherens junctions of the endothelial cells from immunogold electron microcopy. The adherens junctions are considered to be partially dissociated at the site where β-catenin Y142 and β-catenin Y 654 are localized. Thus, the system that protects the adherens junctions and the system that dissociates them may concurrently coexist in the endothelial cells and dissociation and association of the adherens junctions may be constantly repeated at the cell boundary of the endothelial cells. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae is the leading cause of hospital community-acquired pneumonia. Patients with pneumococcal pneumonia may develop complicated parapneumonic effusions or empyema that can lead to pleural organization and subsequent fibrosis. The pathogenesis of pleural organization and scarification involves complex interactions between the components of the immune system, coagulation, and fibrinolysis. EPCR (endothelial protein C receptor) is a critical component of the protein C anticoagulant pathway. The present study was performed to evaluate the role of EPCR in the pathogenesis of S. pneumoniae infection–induced pleural thickening and fibrosis. Our studies show that the pleural mesothelium expresses EPCR. Intrapleural instillation of S. pneumoniae impairs lung compliance and lung volume in wild-type and EPCR-overexpressing mice but not in EPCR-deficient mice. Intrapleural S. pneumoniae infection induces pleural thickening in wild-type mice. Pleural thickening is more pronounced in EPCR-overexpressing mice, whereas it is reduced in EPCR-deficient mice. Markers of mesomesenchymal transition are increased in the visceral pleura of S. pneumoniae–infected wild-type and EPCR-overexpressing mice but not in EPCR-deficient mice. The lungs of wild-type and EPCR-overexpressing mice administered intrapleural S. pneumoniae showed increased infiltration of macrophages and neutrophils, which was significantly reduced in EPCR-deficient mice. An analysis of bacterial burden in the pleural lavage, the lungs, and blood revealed a significantly lower bacterial burden in EPCR-deficient mice compared with wild-type and EPCR-overexpressing mice. Overall, our data provide strong evidence that EPCR deficiency protects against S. pneumoniae infection–induced impairment of lung function and pleural remodeling. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is a major risk factor for cardiovascular disease. Platelets from diabetic patients are hyperreactive and release microparticles that carry activated cysteine proteases or calpains. Whether platelet-derived calpains contribute to the development of vascular complications in diabetes is unknown. Here we report that platelet-derived calpain1 (CAPN1) cleaves the protease-activated receptor 1 (PAR-1) on the surface of endothelial cells, which then initiates a signaling cascade that includes the activation of the tumor necrosis factor (TNF)-α converting enzyme (TACE). The latter elicits the shedding of the endothelial protein C receptor and the generation of TNF-α, which in turn, induces intracellular adhesion molecule (ICAM)-1 expression to promote monocyte adhesion. All of the effects of CAPN1 were mimicked by platelet-derived microparticles from diabetic patients or from wild-type mice but not from CAPN1−/− mice, and were not observed in PAR-1-deficient endothelial cells. Importantly, aortae from diabetic mice expressed less PAR-1 but more ICAM-1 than non-diabetic mice, effects that were prevented by treating diabetic mice with a calpain inhibitor as well as by the platelet specific deletion of CAPN1. Thus, platelet-derived CAPN1 contributes to the initiation of the sterile vascular inflammation associated with diabetes via the cleavage of PAR-1 and the release of TNF-α from the endothelial cell surface. [ABSTRACT FROM AUTHOR]

BackgroundCerebral malaria (CM) is characterized by the sequestration of Plasmodium-infected erythrocytes (pRBCs) to host brain microvasculature beds via P. falciparum erythrocyte membrane protein 1 (PfEMP1). Under normal conditions, activated protein C (APC) bound to endothelial protein C receptor (EPCR) has cytoprotective properties via the activation of protease-activated receptor 1 (PAR1). During malaria infection, pRBCs transports PfEMP1 to the membranes to bind EPCR in the same region as APC. As a result, APC is less capable of inducing cytoprotective effects via PAR1. Two studies involving adult malaria patients revealed that EPCR rs867186-GG allele is associated with protection against severe malaria, while three other studies involving child malaria patients could not show association between EPCR rs867186-GG genotype and severe malaria or increased mortality among children with CM.MethodsWe examined the association between the EPCR rs867186-GG genotype and the protection against cerebral malaria. Peripheral blood samples were collected from 47 malaria patients and 34 healthy individuals from a study conducted from 2004 to 2007 at the NSCB Medical College Hospital in India. CM and malaria-associated complications were defined based on WHO criteria. Genomic DNA was isolated from the peripheral blood mononuclear cells. Primer sequences were designed to contain rs867186 of the PROCR gene (NM 006404) and were used to amplify a 660 bp product as described before. PCR products were purified, and DNA sequences were determined by Sanger Sequencing (Genewiz, NJ). Nonparametric tests were used to compare the groups. To analyze differences in allele frequencies, we used chi-squared or Fisher's exact tests for categorical variables if the expected values were less than 5. P-value

Preeclampsia is a severe pregnancy‐related disease that is found in 3%–5% of pregnancies worldwide and is primarily related to the decreased proliferation and invasion of trophoblast cells and abnormal uterine spiral artery remodelling. However, studies on the pathogenesis of placental trophoblasts are insufficient, and the aetiology of PE remains unclear. Here, we report that endothelial protein C receptor (EPCR), a transmembrane glycoprotein, was down‐regulated in placentas from preeclamptic patients. Moreover, lack of EPCR significantly reduced the trophoblast cell proliferation, invasion and tube formation capabilities. Microscale thermophoresis analysis showed that EPCR directly bound to protease‐activated receptor 1 (PAR‐1), a G protein‐coupled receptor. This change resulted in a substantial reduction in active Rac1 and caused excessive actin rearrangement. Our findings reveal a previously unidentified role of EPCR in the regulation of trophoblast proliferation, invasion and tube formation through promotion of actin polymerization, which is required for normal placental development. [ABSTRACT FROM AUTHOR]

Background: Endothelial protein C receptor (EPCR) plays an anticoagulant and anti‐inflammatory role by promoting the activation of protein C by thrombin bound to thrombomodulin (TBM). Incompatibility between pig TBM and human/primate thrombin is thought to contribute to dysregulated coagulation in pig‐to‐primate organ xenografts, and expression of human TBM (hTBM) in pigs has shown benefit in preclinical models. However, it is not known whether there are incompatibilities—or molecular barriers—between endogenous pig EPCR (pEPCR) and transgenically expressed human TBM. Aim: To clone and express pEPCR, and determine its function in the human protein C pathway in vitro. Methods: Pig endothelial protein C receptor cDNA was generated from pig lung RNA by RT‐PCR. Primate COS‐7 transfectants expressing various combinations of human and pig TBM and EPCR were incubated with human thrombin and human protein C, and tested for TBM cofactor activity. Results: The predicted protein sequence of pEPCR shared 72.3% amino acid sequence identity with hEPCR, and residues critical for protein C binding were conserved. COS‐7 cells transfected with hEPCR, pEPCR or vector showed minimal TBM cofactor activity (0.13 ± 0.04, 0.13 ± 0.02 and 0.14 ± 0.06 U, respectively). The cofactor activity of hTBM‐transfected cells (1.18 ± 0.29 U) was 8‐fold higher than vector‐transfected cells (P =.004) and further increased 4‐fold and 3‐fold by co‐transfection with hEPCR (5.01 ± 1.12 U, P =.004) or pEPCR (3.73 ± 0.65 U, P =.003), respectively. Conclusions: Our data show that pEPCR is largely compatible with the human TBM/thrombin complex, when expressed on COS‐7 cells in vitro, promoting the activation of human protein C. These findings suggest that endogenous pEPCR will enhance the activity of transgenic hTBM in the xenograft setting. [ABSTRACT FROM AUTHOR]

Background: Cerebral malaria (CM) is characterized by the sequestration of Plasmodium -infected erythrocytes (pRBCs) to host brain microvasculature beds via P. falciparum erythrocyte membrane protein 1 (PfEMP1). Under normal conditions, activated protein C (APC) bound to endothelial protein C receptor (EPCR) has cytoprotective properties via the activation of protease-activated receptor 1 (PAR1). During malaria infection, pRBCs transports PfEMP1 to the membranes to bind EPCR in the same region as APC. As a result, APC is less capable of inducing cytoprotective effects via PAR1. Two studies involving adult malaria patients revealed that EPCR rs867186-GG allele is associated with protection against severe malaria, while three other studies involving child malaria patients could not show association between EPCR rs867186-GG genotype and severe malaria or increased mortality among children with CM. Methods: We examined the association between the EPCR rs867186-GG genotype and the protection against cerebral malaria. Peripheral blood samples were collected from 47 malaria patients and 34 healthy individuals from a study conducted from 2004 to 2007 at the NSCB Medical College Hospital in India. CM and malaria-associated complications were defined based on WHO criteria. Genomic DNA was isolated from the peripheral blood mononuclear cells. Primer sequences were designed to contain rs867186 of the PROCR gene (NM 006404) and were used to amplify a 660 bp product as described before. PCR products were purified, and DNA sequences were determined by Sanger Sequencing (Genewiz, NJ). Nonparametric tests were used to compare the groups. To analyze differences in allele frequencies, we used chi-squared or Fisher's exact tests for categorical variables if the expected values were less than 5. P-value <0.05 was considered statistically significant. Results: Our results showed significantly higher rates of AG and GG genotypes in CM patients compared to mild malaria (P = 0.0034). Conclusion: Our results indicate that rs867186-GG or rs867186-AG genotypes are not associated with protection against HCM. [ABSTRACT FROM AUTHOR]

Background: Due to low predictive values of obstructive sleep apnea (OSA) screening tools, there is a need for biomarker for screening of OSA patients at an early stage. The aim of the study was to evaluate differentially expressed proteins in blood and urine samples of OSA patients.Methods: In this study, we used isobaric tagging for relative and absolute quantification (iTRAQ) based proteomics approach to identify differentially expressed proteins, which were subsequently verified and validated using enzyme-linked immunosorbent assay (ELISA) technique in adult OSA patients.Results: Seventeen differentially expressed proteins were selected from iTRAQ data for verification, based on their clinical significance and reproducibility among different iTRAQ experiment sets. Five of these proteins (plasma = 2; urine = 3) were further validated in plasma (non-OSA- = 42; OSA = 198) and urine samples (non-OSA = 46; OSA = 197). ROC curve analysis for all OSA vs. non-OSA subjects ensured optimal diagnostic utility of two urinary proteins: Endothelial protein c receptor (EPCR) (AUC = 73%, cut-off: 35 pg/ml) and dermcidin (AUC = 74%, cut-off: 4.6 pg/ml). For severe OSA, diagnostic accuracy significantly improved with AUC as 88% and 82% for EPCR (cut-off: 46 pg/ml) and dermcidin (cut-off: 5.2 pg/ml) respectively. Sensitivity and specificity of combined performance of both urinary proteins for severe OSA were 94% and 91% respectively.Conclusion: In this study, urinary EPCR and dermcidin emerged as novel biomarkers for screening severe OSA patients. [ABSTRACT FROM AUTHOR]

Objectives To investigate whether activated protein C (APC), a physiological anticoagulant can inhibit the inflammatory/invasive properties of immune cells and rheumatoid arthritis synovial fibroblasts (RASFs) in vitro and prevent inflammatory arthritis in murine antigen-induced arthritis (AIA) and CIA models. Methods RASFs isolated from synovial tissues of patients with RA, human peripheral blood mononuclear cells (PBMCs) and mouse thymus cells were treated with APC or TNF-α/IL-17 and the following assays were performed: RASF proliferation and invasion by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and cell invasion assays, respectively; cytokines and signalling molecules using ELISA or western blot; Th1 and Th17 phenotypes in human PBMCs or mouse thymus cells by flow cytometry. The in vivo effect of APC was evaluated in AIA and CIA models. Results In vitro, APC inhibited IL-1β, IL-17 and TNF-α production, IL-17-stimulated cell proliferation and invasion and p21 and nuclear factor κB activation in RASFs. In mouse thymus cells and human PBMCs, APC suppressed Th1 and Th17 phenotypes. In vivo , APC inhibited pannus formation, cartilage destruction and arthritis incidence/severity in both CIA and AIA models. In CIA, serum levels of IL-1β, IL-6, IL-17, TNF-α and soluble endothelial protein C receptor were significantly reduced by APC treatment. Blocking endothelial protein C receptor, the specific receptor for APC, abolished the early or preventative effect of APC in AIA. Conclusion APC prevents the onset and development of arthritis in CIA and AIA models via suppressing inflammation, Th1/Th17 phenotypes and RASF invasion, which is likely mediated via endothelial protein C receptor. [ABSTRACT FROM AUTHOR]

Objective To investigate the influence and mechanism of Danshen Tongluo Jiedu Tang (Salvia Root Collateral-freeing Removing Toxicity Decoction) combined with bone marrow stem cell transplantation (BMSCT) on myocardial fibrosis in rats with acute myocardial infarction (AMI). Methods The bone marrow mesenchymal stem cells (BMSCs) were isolated and cultured by using whole bone marrow adherence method combined with density gradient centrifugation. The model of AMI was established through ligating the left anterior descending branch (LAD) of coronary artery. The rats were randomly divided into sham-operation group, AMI model group, BMSCT group, Danshen Tongluo Jiedu Tang group (Chinese medicinal group) and Danshen Tongluo Jiedu Tang+BMSCT group (combination group). The model was established in all groups except of sham-operation group, and then Chinese medicinal group and combination group were respectively given orally DTJT and other groups were given orally equivalent saline water once a day for 14 days continuously. The content of collagen in myocardial tissue was observed after Masson staining, and concentration of procollagen type III N-terminal peptide (PⅢP), procollagen type IV N-terminal peptide (PIVP), nitric oxide (NO) and endothelin-1 (ET-1) were detected by using ELISA. The expressions of endothelial protein C receptor (EPCR) and thrombomodulin (TM) were detected by using Western blotting assay, and all data was analyzed by using SPSS 19.0 statistical software. Results Compared with sham-operation group, the protein expressions of EPCR and TM decreased, NO level decreased, levels of ET-1, PⅢP and PⅣP increased, and myocardial collagen fiber generation in varying degrees was observed in other groups (P<0.01). The protein expressions of EPCR and TM and NO level increased, and levels of ET-1, PⅢP and PⅣP and myocardial collagen fiber generation decreased in BMSCT group, Chinese medicinal group and combination group compared with AMI group (P<0.01). The protein expressions of EPCR and TM and NO level increased, and levels of ET-1, PⅢP and PⅣP and myocardial collagen fiber generation decreased in Chinese medicinal group compared with BMSCT group (P<0.01). The protein expressions of EPCR and TM and NO level increased, and levels of ET-1, PⅢP and PⅣP and myocardial collagen fiber generation decreased in combination group compared with Chinese medicinal group (P<0.01). Conclusion Danshen Tongluo Jiedu Tang combined with BMSCT can inhibit myocardial fibrosis, and the mechanism may be related to that the protein expressions of myocardial EPCR and TM are up-regulated and vascular endothelial function is protected in AMI rats. [ABSTRACT FROM AUTHOR]

This article is focused on the pathophysiology, prevalence , clinical manifestations, diagnosis, and treatment C deficiency with increased risk of thrombosis. Activated protein C (aPC) exerts its anticoagulant activity through inactivation of coagulation factors Va and VIIIa. Aside its anticoagulant property, aPC demonstrates anti-inflammatory and cytoprotectiveeffects, which are mediated through the endothelial protein C receptor and the protease-activated receptor-I (PAR-1). Studying and understanding the biological function of APS makes it possible to control coagulation and inflammation and to apply protein C preparations as anticoagulant and cytoprotective drugs in a physicians clinicalpractice.

The endothelial cell protein C receptor (EPCR) serves a key role in activated protein C (APC)-mediated cytoprotective effects in endothelial cells, and is involved in the development of certain types of human cancer. To the best of our knowledge, the present study is the first to demonstrate that EPCR may exert effects on gastric cancer angiogenesis in vitro. To detect microvessel density (MVD), the microvascular endothelial cells were stained for cluster of differentiation (CD)31 and CD34 in 61 cases of surgical resection of gastric carcinoma tissues, and the association between the expression of EPCR protein and MVD was analyzed. In addition, to analyze the effect of EPCR expressed by gastric cancer cells on the proliferation, migration and angiogenic abilities of endothelial cells, human umbilical vein endothelial cells (HUVECs) were cultured with tumor-conditioned medium derived from EPCR knockdown or protease-activated receptor 1 (PAR1)-blocked MGC803 gastric cancer cells. A CCK-8 assay was used to assess the proliferation ability of the HUVECs. A Transwell assay was performed to assess the migration ability of the HUVECs and a Matrigel-based tube formation assay was used to assess the angiogenic activity of the HUVECs. The results demonstrated that the expression of EPCR was correlated with the MVD of gastric cancer tissues. When cultured with tumor-conditioned medium derived from EPCR knockdown or PAR1-blocked MGC803 cells, the proliferation, migration and tubules formation abilities of HUVECs were markedly inhibited markedly. The expression of phosphorylated (p)-extracellular signal regulated kinase 1/2, p-protein kinase B (AKT; s473) and p-AKT (T308) in the HUVECs was decreased. In addition, EPCR knockdown inhibited PAR1 activation in the MGC803 cells. These results indicated that the expression of EPCR in gastric cancer cell line MGC803 contributes to tumor angiogenesis in vitro by activating ERK1/2 and AKT, and that this effect of EPCR is dependent on PAR1 activation. [ABSTRACT FROM AUTHOR]

Objective To explore the effects and mechanism of endothelial protein C receptor (EPCR) on the proliferation and migration of human breast cancer cells MDA-MB-231. Methods MDA-MB-231 cells were divided into the EPCR transfection group, unrelated sequence transfection group, and control group which were transfected with EPCR-siR-NA, siRNA-NC, and empty plasmid, respectively. Cell-ELISA was used to detect the activation of PAR-1 in the membranes of MDA-MB-231. CCK-8 assay was performed to observe the proliferation of cells in each group. Transwell chamber was employed to observe the cells migration. After treatment of anti-PAR-1 antibody, the proliferation and migration abilities of MDA-MB-231 cells were detected by CCK-8 and Transwell assay. Western blotting was used to determine the protein expression levels of Erkl/2 and AKT. Results Compared with the control group and unrelated sequence transfection group, the binding rate of un-cleaved activated PAR-1 antibody increased, and the proliferation and migration abilities significantly decreased in the transfection group ( all P < 0. 05 ). Compared with the control group, after being treated with anti-PAR-1 antibody, the proliferation and migration of MDA-MB-231 cells significantly decreased (both P< 0. 05 ). After knockdown of EPCR or the PAR-1 antibody treatment, the expression of p-Akt (S473 ) and p-Akt (T308 ) significantly decreased in the MDA-MB-231 cells (both P < 0. 05) , but the expression of p-Erkl/2 did not change significantly (P > 0.05). Conclusion EPCR contributes to the proliferation and migration of MDA-MB-231 cells by activating AKT, and this effect of EPCR may be dependent on PAR-1. [ABSTRACT FROM AUTHOR]

Introduction Bone remodeling relies on a delicate balance between formation and resorption of bone tissues, processes in which bone-forming osteoblasts and bone-resorbing osteoclasts play central roles. Recently, we reported that anticoagulant activated protein C (APC) promotes osteoblast proliferation, but the role of the blood coagulation system in bone remodeling remains unclear. In this study, to further elucidate the relationship between bone remodeling and blood coagulation, we investigated the effect of APC on osteoclast differentiation. Materials and methods Normal human osteoclast precursor cells were cultured in their growth medium including soluble RANKL, M-CSF, and FBS, and on days 4 and 7, the culture medium was replaced with the same medium containing various concentrations of APC, protein C (PC), sphingosine 1-phosphate (S1P) receptor agonist, FTY720, or APC + various substances without FBS. On day 8, TRAP-positive multinucleated cells (≥ 3 nuclei) were counted manually using a light microscope. The effects of APC on NF-κB and NFATc1 activation were evaluated using specific ELISA. Results APC suppressed RANKL-induced osteoclast differentiation, and this APC-induced suppression of osteoclast differentiation was inhibited by zymogen protein C and aprotinin, a serine protease inhibitor. Immunohistochemistry and RT-PCR analyses suggested that endothelial protein C receptor (EPCR) and protease-activated receptor-1 (PAR-1) were expressed in osteoclast precursor cells and osteoclasts. Both anti-PAR-1 antibody and anti-EPCR antibody (RCR-252), which blocks APC binding to EPCR, inhibited the APC-induced suppression of osteoclast differentiation. FTY720 had no effect on osteoclast differentiation. However, FTY 720 and S1P receptor antagonist, VP 23019, inhibited the APC-induced suppression of osteoclast differentiation. On the other hand, recombinant soluble human ApoER2 and anti-human ApoER2 inhibited the APC-induced suppression of osteoclast differentiation. Further, APC had no effect on NF-κB and NFATc1 activation. Conclusions APC suppresses human osteoclast differentiation mainly by inhibiting the formation of multinucleated cells via EPCR, PAR-1, S1P receptor, and ApoER2 in a manner that depends on APC protease activity. [ABSTRACT FROM AUTHOR]

The present study investigated the influence of cigarette smoke extract (CSE) and nicotine on the expression of thrombomodulin (TM) and endothelial protein C receptor (EPCR) in human umbilical vein endothelial cells (HUVECs). Smoking is associated with intravascular thrombosis. As a vital anticoagulation cofactor, TM is located on the endothelial cell surface and regulates intravascular coagulation by binding to thrombin, hence activating protein C. Activated protein C is a natural anticoagulant that interacts with EPCR to enhance the function of anticoagulation system. The effects of CSE (0.5-5%) and nicotine (10-3-10-9 mol/l) on the expression of TM and EPCR in HUVECs were observed. Reverse transcription-quantitative polymerase chain reaction and flow cytometric analysis techniques were used for detecting TM and EPCR mRNA and protein expression levels, respectively. After 6-h exposure, TM protein and mRNA expression levels decreased in a dose-dependent manner. Stimulation with 5% CSE for 0, 6, 10, 12 and 24 h led to a decrease in the levels of TM mRNA and protein over time, which reached a peak at 12 h. The levels were significantly reduced compared with the control group (P<0.001). However, CSE had no effect on EPCR. Furthermore, nicotine had no influence on TM and EPCR. In conclusion, the present study supports a novel molecular mechanism of cigarette smoking-associated thrombosis by the decreased expression of TM. Further studies are required to identify specific components in CSE responsible for decreasing TM expression and its associated consequences. [ABSTRACT FROM AUTHOR]

Activation of protein C is greatly enhanced by the presence of thrombomodulin (TM) and endothelial protein C receptor (EPCR) on the endothelial surface. Impairment of the anticoagulant protein C system occurs during endotoxemia and contributes to sepsis-associated hypercoagulability. Previous studies have demonstrated that unfractionated heparin (UFH) can attenuate coagulation in endotoxemic mice. However, whether UFH has an effect on the protein C system remains to be elucidated. The current study evaluated the therapeutic effect of UFH on the protein C system in a mouse model of lipopolysaccharide (LPS)-induced sepsis, and further investigated the effect of UFH on the expression of TM and EPCR in vitro using human umbilical vein endothelial cells (HUVECs). The in vivo data indicated that UFH preconditioning attenuated the decline in circulating activated protein C following LPS administration, and also reduced LPS-induced shedding of TM and EPCR. In HUVECs, LPS stimulation led to the downregulation of TM and EPCR expression, and UFH dose-dependently restored the mRNA and protein levels of TM and EPCR. In addition, UFH inhibited the LPS-induced activation of mitogen-activated protein kinase 14, proto-oncogene tyrosine-protein kinase Src and nuclear factor κB signaling in HUVECs. In summary, these results suggest that UFH has a protective effect on the protein C system during sepsis. Thus, UFH may be a candidate therapeutic agent for the treatment of patients with sepsis. [ABSTRACT FROM AUTHOR]

Plasmodium parasites responsible for malaria follow a complex life cycle of which half takes place inside the human host. Parasites present diverse antigens at different stages of their life cycle and interact with many surface molecules to attach to and enter host cells. The CIDRα1 domain of Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) in infected erythrocytes adheres to one such vascular receptor endothelial protein C receptor (EPCR). EPCR is implicated in the pathogenesis of severe malaria as preferential binding of CIDRα1 to endothelium results in widespread sequestration of infected erythrocytes leading to endothelium inflammation and severe disease. A single EPCR variant S219G is clinically reported to provide protection from severe malaria. In this work, we have collated all single nucleotide polymorphisms (SNPs) in EPCR from dbSNP. We structurally mapped the SNPs on the three-dimensional complex of EPCR and PfEMP1 CIDRα1. Analysis shows that most EPCR mutations lie on the receptor surface and are non-conservative. Of the 11 mutations in the CIDRα1-interaction region of EPCR, S88P, L96V/I, and R98L/H/P/C are seen with comparably higher occurrences in diverse populations. Our structural analysis details a framework of the interactions between the parasite ligand and host factor EPCR. These structural glimpses provide a blueprint for designing both field-based variant sequencing studies and vaccine development. • P. falciparum EMP1 CIDRα1 domain binds to host endothelial protein C receptor (EPCR) • EPCR is implicated in the pathogenesis of severe malaria • Structural mapping of EPCR SNPs reveals mutations in the CIDRα1-interacting region • Our analysis provides a framework of the interplay of variation in EPCR and CIDRα1 • The work will help in designing field-based sequencing studies and develop vaccines [ABSTRACT FROM AUTHOR]

Activated protein C (APC) is a vitamin-K dependent plasma serine protease, which functions as a natural anticoagulant to downregulate thrombin generation in the clotting cascade. APC also modulates cellular homeostasis by exhibiting potent cytoprotective and anti-inflammatory signaling activities. The beneficial cytoprotective effects of APC have been extensively studied and confirmed in a number of preclinical disease and injury models including sepsis, type-1 diabetes and various ischemia/reperfusion diseases. It is now well-known that APC modulates downstream cell signaling networks and transcriptome profiles when it binds to the endothelial protein C receptor (EPCR) to activate protease-activated receptor 1 (PAR1) on various cell types. However, despite much progress, details of the downstream signaling mechanism of APC and its crosstalk with other signaling networks are far from being fully understood. In this review, we focus on the cardioprotective properties of APC in ischemic heart disease and heart failure with a special emphasis on recent discoveries related to the modulatory effect of APC on AMP-activated protein kinase (AMPK), PI3K/AKT, and mTORC1 signaling pathways. The cytoprotective properties of APC might provide a novel strategy for future therapies in cardiac diseases.

Endothelial protein C receptor (EPCR) is a specific receptor for anticoagulant protein C and expressed by human epidermis and cultured keratinocytes. Here we investigated whether: (a) the level of EPCR in keratinocytes is associated with their growth potential; and (b) EPCR is a potential marker for human epidermal stem cells. Human keratinocytes isolated from foreskins or adult skin tissues were transfected with EPCR siRNA or EPCR overexpressing plasmids. Cell proliferation, long term proliferation potential, colony forming efficiency (CFE), and in vitro epidermal regeneration ability of EPCRhigh and EPCRl°w cells were assessed. The expression and colocalization of EPCR with stem cell markers p63, integrin β1, and activation of MAP kinases were detected by flow cytometry, immunofluorescence staining, or Western blot. Results showed that EPCR was highly expressed by the basal layer of skin epidermis. EPCRhigh cells were associated with the highest levels of p63 and integrin β1. Most EPCRhigh cells were smaller in size, formed larger colonies and had a greater long term growth potential, CFE, holoclone formation, and in vitro epidermal regeneration ability when compared to EPCRl°w cells. Blocking EPCR resulted in keratinocyte apoptosis, particularly in nondifferentiated conditions. Cell proliferation and p63 expression were reduced by blocking EPCR and enhanced by overexpressing this receptor. These data indicate that EPCR can regulate p63, is associated with highly proliferative keratinocytes, and is a potential human epidermal stem cell marker. S tem C ells 2017;35:1786-1798 [ABSTRACT FROM AUTHOR]

Ｏｂｊｅｃｔｉｖｅ　Ｔｏ ｏｂｓｅｒｖｅ ｔｈｅ ｐｏｌｙｍｏｒｐｈｉｓｍ ｏｆ ｅｎｄｏｔｈｅｌｉａｌ ｐｒｏｔｅｉｎ Ｃ ｒｅｃｅｐｔｏｒ （ＥＰＣＲ）ｇｅｎｅ ｒｓ８６７１８６Ａ／ Ｇ ｉｎ ｔｈｅ ｐｅｒｉｐｈｅｒａｌ ｂｌｏｏｄ ｏｆ ｐａｔｉｅｎｔｓ ｗｉｔｈ ｓｅｐｓｉｓ. Ｍｅｔｈｏｄｓ　Ｓｉｘｔｙ-ｆｏｕｒ ｐａｔｉｅｎｔｓ ｗｉｔｈ ｓｅｐｓｉｓ （ｓｅｐｓｉｓ ｇｒｏｕｐ，ｍａｌｅ ３８，ｆｅｍａｌｅ ２６） ａｎｄ １１３ ｈｅａｌｔｈｙ ｓｕｂｊｅｃｔｓ （ｃｏｎｔｒｏｌ ｇｒｏｕｐ）ｗｅｒｅ ｓｅｌｅｃｔｅｄ. Ｗｅ ｃｏｌｌｅｃｔｅｄ ５ ｍＬ ｐｅｒｉｐｈｅｒａｌ ｂｌｏｏｄ ｓａｍｐｌｅｓ ｆｒｏｍ ｂｏｔｈ ｔｈｅ ｏｂｓｅｒｖａｔｉｏｎ ｇｒｏｕｐ ａｎｄ ｔｈｅ ｃｏｎｔｒｏｌ ｇｒｏｕｐ. Ｔｈｅ ｐｏｌｙｍｏｒｐｈｉｓｍｓ ｏｆ ＥＰＣＲ ｇｅｎｅ ｒｓ８６７１８６Ａ／ Ｇ ｉｎ ｔｈｅ ｐｅｒｉｐｈｅｒａｌ ｂｌｏｏｄ ｗｅｒｅ ｏｂｓｅｒｖｅｄ， ａｎｄ ｓｅｒｕｍ ｓｏｌｕｂｌｅ ＥＰＣＲ （ｓＥＰＣＲ）ｏｆ ｔｗｏ ｇｒｏｕｐｓ ｗａｓ ｍｅａｓｕｒｅｄ ｂｙ ＥＬＩＳＡ. Ｍｅａｎｗｈｉｌｅ，ｗｅ ｉｎｖｅｓｔｉｇａｔｅｄ ｔｈｅ ｅｆｆｅｃｔ ｏｆ ＥＰＣＲ ｇｅｎｅ ｒｓ８６７１８６Ａ／ Ｇ ｐｏｌｙｍｏｒｐｈｉｓｍｓ ｏｎ ｐｌａｓｍａ ｓＥＰＣＲ ｌｅｖｅｌ ａｎｄ ｓｅｐｓｉｓ ｓｅｖｅｒｉｔｙ. Ｒｅｓｕｌｔｓ　Ｔｈｅ ｆｒｅｑｕｅｎｃｉｅｓ ｏｆ ＡＡ，ＡＧ ａｎｄ ＧＧ ｇｅｎｏｔｙｐｅｓ ａｎｄ Ａ ，Ｇ ａｌｌｅｌｅｓ ｗｅｒｅ ８１. ２％ ，１７. ２％ ，１. ６％ ，８９. ８％ ａｎｄ １0. ２％ ｒｅｓｐｅｃｔｉｖｅｌｙ，ｉｎ ｓｅｐｓｉｓ ｇｒｏｕｐ，ｖｅｒｓｕｓ ８３. ２％ ，１６. ８％ ，0，９１. ６％ ａｎｄ ８. ４％ ｉｎ ｃｏｎｔｒｏｌ ｇｒｏｕｐ，ａｎｄ ｔｈｅｒｅ ｗａｓ ｎｏ ｓｉｇｎｉｆｉｃａｎｔ ｄｉｆｆｅｒｅｎｃｅ ｉｎ ｆｒｅｑｕｅｎｃｙ ｄｉｓｔｒｉｂｕｔｉｏｎ ｏｆ ｔｈｅ ａｂｏｖｅ ｇｅｎｏｔｙｐｅｓ ａｎｄ ａｌｌｅｌｅｓ ｏｆ ｔｗｏ ｇｒｏｕｐｓ （ａｌｌ Ｐ ＞0. 0５）. Ｍａｌｅｓ ｃａｒｒｙｉｎｇ ｒｓ８６７１８６ Ａ ａｌｌｅｌｅ ｏｆ ＥＰＣＲ ｇｅｎｅ ｗｅｒｅ ａｓｓｏｃｉａｔｅｄ ｗｉｔｈ ａ ｓｉｇｎｉｆｉｃａｎｔｌｙ ｉｎｃｒｅａｓｅｄ ｒｉｓｋ ｏｆ ｓｅｐｓｉｓ ｔｈａｎ ｗｏｍｅｎ ｃａｒｒｙｉｎｇ ｔｈｅ ｓａｍｅ ａｌｌｅｌｅｓ （ＯＲ ＝１. ７３５，９５％ ＣＩ：１. 0６３ － ２. ８３３，Ｐ ＜0. 0５）. Ｔｈｅ ｐｌａｓｍａ ｓＥＰＣＲ ｌｅｖｅｌ ｉｎ ｔｈｅ ｓｅｐｓｉｓ ｇｒｏｕｐ ｗａｓ ｓｌｉｇｈｔｌｙ ｈｉｇｈｅｒ ｔｈａｎ ｔｈａｔ ｉｎ ｔｈｅ ｃｏｎｔｒｏｌ ｇｒｏｕｐ ｂｕｔ ｎｏ ｓｉｇｎｉｆｉｃａｎｔ ｄｉｆｆｅｒｅｎｃｅ ｗａｓ ｆｏｕｎｄ （ａｌｌ Ｐ ＞0. 0５）. Ｔｈｅｒｅ ｗａｓ ｎｏ ｓｉｇｎｉｆｉｃａｎｔ ｄｉｆｆｅｒｅｎｃｅ ｉｎ ｐｌａｓｍａ ｓＥＰＣＲ ｌｅｖｅｌ ａｎｄ ｓｅｖｅｒｉｔｙ ｏｆ ｓｅｐｓｉｓ ｂｅｔｗｅｅｎ ｐａｔｉｅｎｔｓ ｗｉｔｈ ｄｉｆｆｅｒｅｎｔ ｒｓ８６７１８６Ａ／ Ｇ ｇｅｎｏｔｙｐｅｓ （ａｌｌ Ｐ ＞0. 0５）. Ｃｏｎｃｌｕｓｉｏｎｓ 　Ｔｈｅ ＡＡ ｇｅｎｏｔｙｐｅ ｏｒ Ａ ａｌｌｅｌｅ ｉｓ ｍｏｒｅ ｆｒｅｑｕｅｎｔｌｙ ｆｏｕｎｄ ｉｎ ＥＰＣＲ ｇｅｎｅ ｒｓ８６７１８６Ａ／ Ｇ ｉｎ ｔｈｅ ｐｅｒｉｐｈｅｒａｌ ｂｌｏｏｄ ｏｆ ｐａｔｉｅｎｔｓ ｗｉｔｈ ｓｅｐｓｉｓ. Ｔｈｅ ｐｏｌｙｍｏｒｐｈｉｓｍ ｏｆ ＥＰＣＲ ｇｅｎｅ ｒｓ８６７１８６Ａ／ Ｇ ｍａｙ ｂｅ ａｓｓｏｃｉａｔｅｄ ｗｉｔｈ ｔｈｅ ｉｎｃｒｅａｓｅｄ ｒｉｓｋ ｏｆ ｓｅｐｓｉｓ． [ABSTRACT FROM AUTHOR]

Background: Brain thrombin activity is increased following acute ischemic stroke and may play a pathogenic role through the protease-activated receptor 1 (PAR1). In order to better assess these factors, we obtained a novel detailed temporal and spatial profile of thrombin activity in a mouse model of permanent middle cerebral artery occlusion (pMCAo). Methods: Thrombin activity was measured by fluorescence spectroscopy on coronal slices taken from the ipsilateral and contralateral hemispheres 2, 5, and 24 h following pMCAo (n = 5, 6, 5 mice, respectively). Its spatial distribution was determined by punch samples taken from the ischemic core and penumbra and further confirmed using an enzyme histochemistry technique (n = 4). Levels of PAR1 were determined using western blot. results: Two hours following pMCAo, thrombin activity in the stroke core was already significantly higher than the contralateral area (11 ± 5 vs. 2 ± 1 mU/ml). At 5 and 24 h, thrombin activity continued to rise linearly (r = 0.998, p = 0.001) and to expand in the ischemic hemisphere beyond the ischemic core reaching deleterious levels of 271 ± 117 and 123 ± 14 mU/ml (mean ± SEM) in the basal ganglia and ischemic cortex, respectively. The peak elevation of thrombin activity in the ischemic core that was confirmed by fluorescence histochemistry was in good correlation with the infarcts areas. PAR1 levels in the ischemic core decreased as stroke progressed and thrombin activity increased. conclusion: In conclusion, there is a time- and space-related increase in brain thrombin activity in acute ischemic stroke that is closely related to the progression of brain damage. These results [ABSTRACT FROM AUTHOR]

Background Endothelial injury is believed to play an important role in the evolution of pancreatic microcirculatory dysfunction and pancreatic necrosis (PN) in patients with acute pancreatitis (AP). The aim of this study was to investigate the role of three endothelial markers (von Willebrand factor, vWF; E-selectin; endothelial protein C receptor, EPCR) in the early phase of AP, especially the relationship between endothelial markers and PN. Methods From March 2015 to March 2016, 57 AP patients admitted within 72 h of symptom onset in our hospital were included for this study. Blood samples were taken on admission and the clinical characteristics and outcomes of these patients were recorded. The levels of vWF, E-selectin and EPCR were measured using ELISA for analysis and compared with other severity markers of AP. Results All the three markers were significantly different in healthy control, mild, moderate and severe AP patients. Moreover, the endothelial markers, especially vWF, also showed significant difference in patients with different extent of PN, as well as those with or without MODS. Additionally, the levels of endothelial markers correlated well with other commonly used markers of AP severity. Conclusion Elevated endothelium-related mediators (vWF, E-selectin and EPCR) appear to participate in the development of PN and may be a potential indicator of overall prognosis. Our results may help clinicians better understand the pathophysiological process of the development of PN. [ABSTRACT FROM AUTHOR]

Proteina C, o protează serinică dependentă de vitamina K, sintetizată in hepatocite ca zimogen inactiv, se activează sub acţiunea trombinei în complex cu trombomodulina endotelială. Un receptor endotelial al proteinei C (EPCR) intervine atât în activarea cât şi în optimizarea activităţii proteinei C activate având ca efect degradarea proteolitică a factorilor coagulării Va şi VIIIa şi exercitând astfel un eficient efect anticoagulant. S-a dovedit că citokinele proinflamatorii perturbă activarea la nivel endotelial inducând internalizarea şi degradarea trombomodulinei şi indepărtând EPCR de la suprafaţa celulelor endoteliale. Cercetări clinice şi experimentale au demonstrat că reacţia de fază acută se asociază cu o comutare a sintezei hepatice de proteine ducând la creşterea fibrinogenemiei, a factorului VIII:C şi a nivelului de α1 inhibitor al proteazelor, în timp ce sinteza de zimogen a proteinei C se reduce. Pe de altă parte, infuziile de proteina C activată protejează faţă de şocul toxico-septic exercitând nu doar efecte anticoagulante, dar şi o activitate antiinflamatorie.

As an important part of the protein C anticoagulant system, endothelial protein C receptor (EPCR) plays a critical role in the process of anti- coagulation and anti- inflammation. The presence of EPCR single nucleotide polymorphism (SNP) affects the levels of soluble endothelial protein C receptor (sEPCR), and susceptibility to varieties of diseases. This article reviews the relationship between EPCR gene polymorphisms and thrombotic diseases，malaria，sepsis and other diseases. [ABSTRACT FROM AUTHOR]

Introduction Fondaparinux (FDX) was demonstrated to be cardioprotective in a rat model of myocardial ischemia reperfusion. In this model, FDX reduced infarct size after 2 h of reperfusion, involving the activation of the survivor activating factor enhancement (SAFE) pathway as early as 30 min post-reperfusion. Our aim was to study if this cardioprotection could be explained by anti-inflammatory mechanisms and a protective effect on vessels. Methods Wistar male rats were subjected to 40 minutes (min) of myocardial ischemia, followed by 30 min or 2 h of reperfusion. Rats were randomized into four groups: control 30 min (n = 7), FDX 30 min (n = 7), control 2 h (n = 7), and FDX 2 h (n = 7). The FDX groups received 10 mg/kg injection of FDX 10 min prior to initiating reperfusion. We studied: 1) mRNA expression of endothelial markers, such as thrombomodulin (TM), endothelial protein C receptor (EPCR), and tissue factor (TF) and 2) proteic expression of ICAM-1, NF-κB, IκB, and JNK. Leukocyte infiltration was assessed by histochemistry. We also evaluated TM and EPCR mRNA expression in a model of isolated rat mesenteric arteries incubated with FDX. Results FDX upregulated the expression of TM and EPCR mRNA in the models of myocardial infarction and isolated mesenteric arteries. No difference was observed between the treated and control groups regarding the expression of pro-inflammatory signaling proteins, adhesion molecules, and leukocyte infiltration after 2 h of reperfusion. Conclusion The cardioprotective effect of FDX at early-stage reperfusion could be related to vascular protection, yet not to an anti-inflammatory effect. [ABSTRACT FROM AUTHOR]

Background: Malaria is still one of the most prevalent infectious diseases in the world. Sequestration of infected erythrocytes (IEs) is the prime mediator of disease. Cytoadhesion of IEs is mediated by members of the highly diverse Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1). A restricted sub-set of var genes encoding for PfEMP1s possessing the domain cassettes DC8 and DC13 were found to bind to the endothelial protein C receptor (EPCR). These var genes were shown to be highly expressed by parasites from patients with severe malaria clinical outcomes compared to those from patients with uncomplicated symptoms. Methods: In order to further study the molecular mechanisms underlying DC8/DC13 expressing IEs adhesion to EPCR, a method was developed to produce highly pure recombinant EPCR. The IT4 parasite strain was selected on either anti-IT4-VAR19 purified IgG, EPCR or human brain endothelial cell line and their var gene expression profiles as well as their binding phenotypes were compared. The N-terminal region of IT4-VAR19 comprising a full-length DC8 cassette as well as the single EPCR binding CIDRα1.1 domain were also produced, and their immune recognition (IgG) was assessed using plasma samples from Beninese children presenting acute mild malaria, severe malaria or cerebral malaria at the time of their admission to the clinic, and from convalescent-phase plasma collected 30 days after antimalarial treatment. Results: The multi-domain VAR19-NTS-DBLγ6 binds to EPCR with a greater affinity than the CIDRα1.1 domain alone and this study also demonstrates that VAR19-NTS-DBLγ6 binding to the EPCR-expressing endothelial cell line (HBEC5i) is more pronounced than that of the CIDRα1.1 domain alone. IT4-VAR19 represents the preferentially expressed- PfEMP1 when FCR3-IEs are selected based on their capability to bind EPCR. Notably, no significant difference in the levels of antibodies towards IT4-VAR19 antigens was observed within all clinical groups between plasma samples collected during the acute malaria phase compared to samples collected 30 days after anti-malaria treatment. Conclusions: These data indicate that even being the preferentially selected IT4-EPCR-binding variant, the IT4- VAR19-DC8 region does not appear to be associated with the acquisition of antibodies during a single severe paediatric malaria episode in Benin. [ABSTRACT FROM AUTHOR]

This study examines the effects of progesterone on blood-brain barrier (BBB) integrity following thrombin administration. Thrombin is expressed in many diseases which affect neural tissue and is associated with breakdown of the BBB. Progesterone has shown protective effects on the BBB in stroke and traumatic brain injury. Methods Mouse brain endothelial (bEnd.3) cells were treated with progesterone (20 μmol/l) for 24 h before thrombin administration (60 U/ml). BBB permeability was measured by transendothelial electrical resistance (TEER), because TEER decrease is associated with BBB compromise. Tight junction (TJ) proteins (occludin, claudin-5, and zonula occludens-1) and endothelial protein C receptor (EPCR) were analyzed. Results Thrombin decreased TEER and progesterone prevented that decrease. TJ proteins and EPCR were also decreased after thrombin treatment and progesterone treatment blocked that effect. Conclusion: Progesterone can attenuate thrombin-induced BBB disruption by blocking the degradation of TJ proteins and EPCR in bEnd.3 cells. [ABSTRACT FROM AUTHOR]

Endothelial dysfunction and disruption of the blood-brain barrier have been found to be associated with Parkinson's disease (PD). However, the mechanisms underlying these effects have yet to be elucidated. It has also been found that activated protein C (APC) displays neuroprotective properties. Presently, the effects of APC on PD remain unknown. Using a 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) neurotoxin rodent model of PD, we found that administration of MPTP can reduce expression of endothelial protein C receptor (EPCR), an N-glycosylated type I membrane protein that has the ability to enhance protein C activation. However, the use of MPTP does not alter levels of thrombomodulin. These findings were verified in an in vitro study showing that 1-methyl-4-phenylpyridinium (MPP+) treatment leads to suppression of EPCR along with reduction of protein C activation in human primary endothelial cells. Importantly, our results display that activation of the transcriptional factor SP1 is involved in the inhibitory effects of MPTP/MPP+ on EPCR expression. We found that using 300 nM of the SP1 inhibitor MIT can abolish the effects of MPP+ on EPCR expression. Consistently, SP1 silencing using small RNA interference was able to prevent the inhibitory effects of MPTP/MPP+ on the reduction of EPCR expression and impairment of protein C activation. Importantly, our results indicate that overexpression of SP1 inhibits EPCR promoter activity. Our study suggests that EPCR-APC may be a potential therapeutic target for endothelial dysfunction in PD. [ABSTRACT FROM AUTHOR]

The past 10 years have generated new insights into the complex interaction between CD36 (cluster of differentiation 36) and malaria. These range from the crystallization of the CD36 homolog, LIMPII (lysosomal integral membrane protein II), permitting modeling of CD36 and its binding to diverse ligands, to cell biology-based studies of CD36 and large population genetic studies assessing the association of CD36 polymorphisms and malarial disease severity. Collectively these lines of evidence indicate that a receptor other than CD36 is associated with severity. CD36 plays an important role in innate immunity and in the phagocytic uptake of multiple pathogens including malaria. CD36 polymorphisms lack association with severity, and isolates that cause severe disease primarily bind to endothelial protein C receptor (EPCR) rather than to CD36. [ABSTRACT FROM AUTHOR]

Septic shock is a leading cause of death in intensive care units and a public health problem. Uncontrolled systemic inflammatory response plays a critical role in the pathogenesis of sepsis and septic shock. Alterations in the mechanisms controlling coagulation and inflammation may lead to disseminated intravascular coagulation. The interaction between inflammation and coagulation is central to the pathogenesis of both septic shock and sepsis. Thrombomodulin, protein C, thrombin, and endothelial protein C receptor (T-PC-T-EPCR) bind simultaneously forming a complex on the surface of the endothelium. This complex maintains the endothelial microenviroment in an anti-inflammatory and anticoagulant state. The objective of this paper is to review the critical role that TM-PC-T-EPCR complex plays in the interaction between inflammation and coagulation in sepsis and the use of recombinant thrombomodulin as a new therapeutic alternative in the management of serious sepsis and septic shock. [ABSTRACT FROM AUTHOR]

Aim: Thrombomodulin (TM) and endothelial protein C receptor (EPCR) are 2 transmembrane proteins that are thought to play an important role in cancer. We aimed to discover whether these 2 proteins are prognostic indicators in colorectal cancer. Materials and methods: Plasma TM and EPCR levels were measured using the ELISA method in 50 patients in different tumor stages that had been recently diagnosed with colorectal cancer and in a healthy control group of 50 people. Results: In colorectal cancer patients, higher plasma TM (21.3 ± 22.8 ng/mL, 13.2 ± 16.2 ng/mL, P = 0.010) and plasma EPCR levels (149.9 ± 79.6, 113.3 ± 49.3, P = 0.007) were determined compared to the control group. No statistically significant relationship was present between plasma TM, EPCR levels and tumor stage, tumor localization, tumor differentiation, lymphovascular invasion state, microvascular thrombus existence, and thrombosis progression (P > 0.05). Conclusion: We think that these 2 proteins are released into plasma as an indicator of endothelial dysfunction and can play a role in pathogenesis and biology of colorectal cancer. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to evaluate the mechanisms of cardiopulmonary bypass (CPB)-induced dysregulation between thrombin and its regulatory anticoagulant activated protein C (APC). Design: A prospective observational cohort study. Setting: A tertiary care university hospital and associated research laboratory. Patients: Twenty patients undergoing elective coronary artery bypass surgery with (n = 10) or without CPB (n = 10). Interventions: Blood samples were collected at 7 time points: preinduction; after heparin; 1 hour after the institution of CPB (or the completion of distal anastomoses in off-CPB group); after protamine; and at 0, 4, and 18 hours in the Intensive care unit (ICU). Samples were analyzed for prothrombin fragments (F1+2), thrombin-antithrombin complexes, protein C (PC), APC, soluble thrombomodulin (sTM), and soluble endothelial protein C receptor (sEPCR). Measurements and Main Results: F1+2 levels increased significantly 1 hour after the initiation of CPB in comparison with baseline (2.7 ± 0.5 v 0.5 ± 0.2 nmol/L, p < 0.001) (mean ± standard deviation) and remained elevated until 4 hours after ICU admission (p < 0.001). In contrast, APC levels did not show any significant changes over time in either group. sEPCR, sTM, and PC levels did not change during CPB although sEPCR decreased significantly after the termination of CPB compared with baseline in the CPB group. Conclusions: Exposure to CPB is associated with a distinct thrombin surge that continues postoperatively for 4 hours. The impaired ability to generate APC reflects a complex process that is not associated with increased levels of sEPCR and thrombomodulin during CPB. Further studies are required to evaluate the regulation of the host APC response in cardiac surgery. [Copyright &y& Elsevier]

Abstract: Thrombomodulin (TM) on the cell-surface of cerebrovascular endothelial cells (CECs) is released into blood upon CEC damage. TM promotes activation of protein C (APC), an anticoagulant, anti-inflammatory, neuroprotective molecule that protects CECs and impedes inflammatory cell migration across the blood–brain barrier (BBB). Multiple sclerosis (MS) is associated with CEC damage and BBB dysfunction. We evaluated soluble TM (sTM) levels as a biomarker of BBB integrity and whether glatiramer acetate (GA) influenced sTM levels in MS patients. sTM levels quantified by 2-site ELISA from sera of healthy controls and systemic lupus erythematosus (SLE) patients (CEC-damage positive control) were compared with levels from patients with relapsing–remitting (RRMS) or secondary-progressive MS (SPMS), stratified as: RRMS/GA/no relapse, RRMS/GA/in relapse, RRMS no GA/no relapse, RRMS/no GA/in relapse; and SPMS/no GA. Additionally, soluble endothelial protein C receptor (sEPCR) levels were assessed in the non-stratified MS group, SLE patients, and controls. sTM levels were highest in RRMS patients taking GA with or without relapse, followed in decreasing order by SLE, RRMS/no GA/in relapse, SPMS, RRMS/no GA/no relapse, healthy controls. sEPCR levels were highest in MS patients, then SLE, then controls. sTM may be a useful biomarker of BBB integrity in RRMS patients. Further evaluation of sEPCR is needed. The finding that the highest sTM levels were in RRMS patients taking GA is interesting and warrants further investigation. [Copyright &y& Elsevier]

Abstract: Adult hematopoietic stem cells (HSCs) are maintained in a microenvironment known as the stem cell niche. The regulation of HSCs in fetal liver (FL) and their niche, however, remains to be elucidated. In this study, we investigated the role of N-cadherin (N-cad) in the maintenance of HSCs during FL hematopoiesis. By using anti-N-cad antibodies (Abs) produced by our laboratory, we detected high N-cad expression in embryonic day 12.5 (E12.5) mouse FL HSCs, but not in E15.5 and E18.5 FL. Immunofluorescence staining revealed that N-cad+c-Kit+ and N-cad+ endothelial protein C receptor (EPCR)+ HSCs co-localized with Lyve-1+ sinusoidal endothelial cells (ECs) in E12.5 FL and that some of these cells also expressed N-cad. However, N-cad+ HSCs were also observed to detach from the perisinusoidal niche at E15.5 and E18.5, concomitant with a down-regulation of N-cad and an up-regulation of E-cadherin (E-cad) in hepatic cells. Moreover, EPCR+ long-term (LT)-HSCs were enriched in the N-cad+Lin−Sca-1+c-Kit+ (LSK) fraction in E12.5 FL, but not in E15.5 or E18.5 FL. In a long-term reconstitution (LTR) activity assay, higher engraftment associated with N-cad+ LSK cells versus N-cad− LSK cells in E12.5 FL when transplanted into lethally irradiated recipient mice. However, the higher engraftment of N-cad+ LSK cells decreased subsequently in E15.5 and E18.5 FL. It is possible that N-cad expression conferred higher LTR activity to HSCs by facilitating interactions with the perisinusoidal niche, especially at E12.5. The down-regulation of N-cad during FL hematopoiesis may help us better understand the regulation and mobility of HSCs before migration into BM. [Copyright &y& Elsevier]

Metabolic syndrome is associated with significant hypercoagulable prothrombotic tendency; however, the mechanism for the prothrombotic state is not completely understood. We hypothesize that higher circulating plasma free fatty acids (FFAs) in metabolic syndrome inhibit the endothelial thrombomodulin (TM)-endothelial protein C receptor (EPCR) pathway, thereby promoting thrombus formation. Human umbilical vein endothelial cells were cultured in media supplemented with various doses of palmitic acid (PA), in the presence or absence of JNK inhibitor, and the expression of TM and EPCR was measured by western blot. The thrombotic state of high fat fed C57BL/6J mice was examined by tail bleeding time and deep venous thrombosis (DVT) model. As a result, PA inhibited the expression of TM and EPCR in endothelial cells, and this effect was blunted by inhibiting JNK signaling. High fat diet fed mice had higher level of circulating FFAs and exhibited prothrombotic state, evidenced by increased tail bleeding time and enlarged thrombotic size in DVT model, compared to the control diet fed mice. Hence, FFAs inhibit TM-EPCR-Protein C system in endothelial cells through activating JNK signaling, which may be a mechanism for the prothrombotic state in metabolic syndrome. [ABSTRACT FROM AUTHOR]

Plasma protein C is a serine protease zymogen that is transformed into the active, trypsin-like protease, activated protein C (APC), which can exert multiple activities. For its anticoagulant action, APC causes inactivation of the procoagulant cofactors, factors Va and VIIIa, by limited proteolysis, and APC's anticoagulant activity is promoted by protein S, various lipids, high-density lipoprotein, and factor V. Hereditary heterozygous deficiency of protein C or protein S is linked to moderately increased risk for venous thrombosis, while a severe or total deficiency of either protein is linked to neonatal purpura fulminans. In recent years, the beneficial direct effects of APC on cells which are mediated by several specific receptors have become the focus of much attention. APC-induced signaling can promote multiple cytoprotective actions which can minimize injuries in various preclinical animal injury models. Remarkably, pharmacologic therapy using APC demonstrates substantial neuroprotective effects in various murine injury models, including ischemic stroke. This review summarizes the molecules that are central to the protein C pathways, the relationship of pathway deficiencies to venous thrombosis risk, and mechanisms for the beneficial effects of APC. [ABSTRACT FROM AUTHOR]

Activated protein C (APC) is one of the key proteinases of hemostasis exhibiting anti-coagulant, anti-inflammatory, and protective functions. In the present work, the anti-apoptotic effect of the proteinase on the glutamate toxicity model in cultured hippocampal neurons has been discovered. It is demonstrated that high concentrations of glutamate induce translocation of p65 subunit of transcription factor NF-κB into the nucleus, while low concentrations of APC prevent this effect of the neurotransmitter. Moreover, helenalin, a specific inhibitor of NF-κBp65, similar to APC, increased survival of neurons under toxic conditions. Using specific blocking antibodies, we have revealed that APC via its own receptor (endothelial protein C receptor) and protease activated receptor 1 (PAR1) inhibits glutamate-induced activation of transcription factor NF-κB. Thus, APC in low concentrations protects hippocampal neurons from glutamate-induced death through a receptor-dependent regulation of the activity of p65 subunit of transcription factor NF-κB. [ABSTRACT FROM AUTHOR]

Background: Blood coagulation is an essential determinant of coronary artery disease (CAD). Soluble Endothelial Protein C Receptor (sEPCR) may be a biomarker of a hypercoagulable state. We prospectively investigated the relationship between plasma sEPCR levels and the risk of cardiovascular events (CVE). Methods: We measured baseline sEPCR levels in 1673 individuals with CAD (521 with acute coronary syndrome [ACS] and 1152 with stable angina pectoris [SAP]) from the AtheroGene cohort. During a median follow up of 3.7 years, 136 individuals had a CVE. In addition, 891 of these CAD patients were genotyped for the PROCR rs867186 (Ser219Gly) variant. Results: At baseline, sEPCR levels were similar in individuals with ACS and SAP (median: 111 vs. 115 ng/mL respectively; p=0.20). Increased sEPCR levels were found to be associated with several cardiovascular risk factors including gender (p=0.006), soluble Tissue Factor levels (p=0.0001), diabetes (p=0.0005), and factors reflecting impaired renal function such as creatinine and cystatin C (p<0.0001). sEPCR levels were not significantly associated with the risk of CVE (median: 110 and 114 ng/mL in individuals with and without future CVE respectively; p=0.68). The rs867186 variant was found to explain 59% of sEPCR levels variability (p<10-200) but did not associate with CVE risk. Conclusion: Our findings show that in patients with CAD, circulating sEPCR levels are related to classical cardiovascular risk factors and renal impairment but are not related to long-term incidence of CVE. [ABSTRACT FROM AUTHOR]