Meta-analysis of the endothelial protein C receptor rs867186 genotype in malaria

Abstract The interaction between the P. falciparum erythrocyte membrane protein 1 (PfEMP1) on the surface of parasitized red blood cells (pRBC) and the endothelial cells (EC) receptors during P. falciparum infection results in the sequestration of pRBC from blood circulation. The amount of sequestration is determined by specific interactions among PfEMP1 and several host adhesion receptors, including intercellular adhesion molecule 1 (ICAM-1), CD36, and endothelial protein C receptor (EPCR). PfEMP1 is composed of multiple domains such as the cysteine-rich inter domain region (CIDR) and Duffy binding –like (DBL) domains. CIDRα1 competitively binds to EPCR with activated protein C (APC) and impair cytoprotective and anticoagulant effects by APC, which plays an important role in severe malaria (SM) pathogenesis such as cerebral malaria (CM) and severe malaria anemia (SMA). The strategy to inhibit EPCR binding to pRBC while to concomitantly strengthen its binding to APC may be crucial in restoring impaired protein C (PC) system’s function. The purpose of this study is to evaluate the association between severity of malaria and the EPCR genotypes as well as the soluble EPCR (sEPCR), and the study also addresses the physiological relevance of EPCR genetic polymorphism. In this study, we conducted meta-analysis on the eligible studies by comparing the frequency of EPCR rs867186-GG versus rs867186- GA and -AA genotype in SM, mild malaria (MM) or uncomplicated malaria (UM) patients and healthy individuals from Thailand, Uganda, Benin, Tanzania, and Ghana. We also determined the relationship between rs867186 genotype and sEPCR levels. Our results showed that the gene type of rs867186-GG is higher in MM/UM than in SM patients. SM patients carrying the rs867186-GG genotype have higher plasma soluble EPCR (sEPCR) levels than in rs867186-AG and rs867186-AA carriers. A significant difference is seen with the higher plasma sEPCR expression among MM/UM patients carrying the rs867186-AG genotype compared to those carrying rs867186-AA. Similarly, the rs867186-GG is associated with sEPCR level in healthy individuals. In conclusion, this meta-analysis demonstrates that pRBCs and EPCR interactions are associated with malaria severity, and treatments that block pRBC binding to EPCR via PfEMP1 CIDRα1 could be a potential therapy for SM.

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A meta-analysis of the endothelial protein C receptor rs867186 genotype in malaria

10.21203/rs.2.9986/v2 ◽

2019 ◽

Author(s):

Lin Yang ◽

Ruilian Xin ◽

Shanchun Guo ◽

Mingli Liu

Keyword(s):

Endothelial Cells ◽

Severe Malaria ◽

Protein C ◽

Meta Analysis ◽

Intercellular Adhesion Molecule ◽

Healthy Individuals ◽

Endothelial Protein C Receptor ◽

Intercellular Adhesion Molecule 1 ◽

Soluble Epcr ◽

Malaria Severity

Abstract BACKGROUND : During P. falciparum infection, the binding of P. falciparum erythrocyte membrane protein 1 (PfEMP1) to endothelial cells (EC) results in the sequestration of pRBC. Several receptors located on the endothelial cells, including intercellular adhesion molecule 1 (ICAM-1), CD36, and endothelial protein C receptor (EPCR), contribute to PfEMP1 adhesion to the microvasculature. PfEMP1, expressed on the surface of parasitized red blood cells (pRBC), is composed of cysteine-rich interdomain regions (CIDR) and Duffy binding-like (DBL) domains. CIDRα1 competitively binds to EPCR with activated protein C (APC) and impairs cytoprotective and anticoagulant effects by APC, which plays important roles in severe malaria (SM) pathogenesis such as cerebral malaria (CM) and severe malaria anemia (SMA). The strategy to inhibit EPCR binding to pRBC while concomitantly strengthen its binding to APC may be crucial in restoring disrupted protein C (PC) system’s function. The purpose of this study is to evaluate the association between malaria severity and the EPCR genotypes as well as with soluble EPCR (sEPCR), and the study also addresses the physiological relevance of EPCR genetic polymorphism. RESULTS : In this study, we conducted a meta-analysis on the eligible studies by comparing the frequency of EPCR rs867186-GG versus rs867186-GA and -AA genotype in SM, mild malaria (MM) or uncomplicated malaria (UM) patients and healthy individuals from Thailand, Uganda, Benin, Tanzania, and Ghana. We also determined the relationship between rs867186 genotype and sEPCR levels. Our results showed that the genotype rs867186-GG is higher in MM/UM than in SM patients. SM patients carrying the rs867186-GG genotype have higher plasma soluble EPCR (sEPCR) levels than in rs867186-AG and rs867186-AA carriers. MM/UM patients carrying the rs867186-AG genotype have significantly higher level of sEPCR compared to those carrying rs867186-AA. Similarly, the rs867186-GG is associated with high sEPCR level in healthy individuals. CONCLUSIONS : This meta-analysis demonstrates that pRBCs and EPCR interactions are associated with malaria severity, and treatments that block their binding via PfEMP1 CIDRα1 could be a potential therapy for SM.

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A meta-analysis of the endothelial protein C receptor rs867186 genotype in malaria

10.21203/rs.2.9986/v3 ◽

2019 ◽

Author(s):

Lin Yang ◽

Ruilian Xin ◽

Shanchun Guo ◽

Mingli Liu

Keyword(s):

Endothelial Cells ◽

Severe Malaria ◽

Protein C ◽

Meta Analysis ◽

Intercellular Adhesion Molecule ◽

Healthy Individuals ◽

Endothelial Protein C Receptor ◽

Intercellular Adhesion Molecule 1 ◽

Soluble Epcr ◽

Malaria Severity

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Protein C system defects inflicted by the malaria parasite protein PfEMP1 can be overcome by a soluble EPCR variant

Thrombosis and Haemostasis ◽

10.1160/th15-01-0018 ◽

2015 ◽

Vol 114 (11) ◽

pp. 1038-1048 ◽

Cited By ~ 30

Author(s):

Eveline A. M. Bouwens ◽

Ibai Tamayo ◽

Louise Turner ◽

Christian W. Wang ◽

Monique Stins ◽

...

Keyword(s):

Endothelial Cells ◽

Severe Malaria ◽

Protein C ◽

Cellular Response ◽

Malaria Parasite ◽

Vascular Endothelial Cells ◽

Protective Effects ◽

Endothelial Protein C Receptor ◽

Parasite Protein ◽

Soluble Epcr

SummaryThe Endothelial Protein C receptor (EPCR) is essential for the anticoagulant and cytoprotective functions of the Protein C (PC) system. Selected variants of the malaria parasite protein, Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) associated with severe malaria, including cerebral malaria, specifically target EPCR on vascular endothelial cells. Here, we examine the cellular response to PfEMP1 engagement to elucidate its role in malaria pathogenesis. Binding of the CIDRα1.1 domain of PfEMP1 to EPCR obstructed activated PC (APC) binding to EPCR and induced a loss of cellular EPCR functions. CIDRα1.1 severely impaired endothelial PC activation and effectively blocked APC-mediated activation of protease-activated receptor-1 (PAR1) and associated barrier protective effects of APC on endothelial cells. A soluble EPCR variant (E86A-sEPCR) bound CIDRα1.1 with high affinity and did not interfere with (A)PC binding to cellular EPCR. E86A-sEPCR used as a decoy to capture PfEMP1, permitted normal PC activation on endothelial cells, normal barrier protective effects of APC, and greatly reduced cytoadhesion of infected erythrocytes to brain endothelial cells. These data imply important contributions of PfEMP1-induced protein C pathway defects in the pathogenesis of severe malaria. Furthermore, the E86A-sEPCR decoy provides a proof-of-principle strategy for the development of novel adjunct therapies for severe malaria.

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The endothelial protein C receptor rs867186-GG genotype is associated with increased soluble EPCR and could mediate protection against severe malaria

Scientific Reports ◽

10.1038/srep27084 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 9

Author(s):

Estela Shabani ◽

Robert O. Opoka ◽

Paul Bangirana ◽

Gregory S. Park ◽

Gregory M. Vercellotti ◽

...

Keyword(s):

Severe Malaria ◽

Protein C ◽

Endothelial Protein C Receptor ◽

Soluble Epcr

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Effects of membrane and soluble EPCR on the hemostatic balance and endotoxemia in mice

Blood ◽

10.1182/blood-2006-06-032086 ◽

2006 ◽

Vol 109 (3) ◽

pp. 1003-1009 ◽

Cited By ~ 20

Author(s):

Xunzhen Zheng ◽

Weihong Li ◽

Jian-Ming Gu ◽

Dongfeng Qu ◽

Gary L. Ferrell ◽

...

Keyword(s):

Protein C ◽

Activated Protein C ◽

Factor Xa ◽

Full Length ◽

Wild Type ◽

Endothelial Protein C Receptor ◽

Thrombotic Diseases ◽

Soluble Epcr

Abstract Recent studies have shown that endothelial protein C receptor (EPCR) polymorphisms and soluble EPCR levels are associated with thrombotic diseases. It is unknown whether membrane EPCR (mEPCR) heterozygosity and/or physiologically elevated sEPCR levels directly impact the hemostatic balance and the outcome of endotoxemia. In these studies, thrombin infusion experiments revealed that EPCR heterozygosity (Procr+/−) impaired protein C activation by approximately 30%. Infusion of factor Xa with phospholipid demonstrated that the Procr+/−genotype increased the coagulant response relative to wild-type mice. Challenge of the Procr+/− mice with lipopolysaccharide (LPS) did not significantly exaggerate their response compared with wild-type mice. We also generated mice in which one allele of full-length EPCR was replaced by sEPCR (Procrs/+). Compared with Procr+/− mice, Procrs/+ mice had 5-fold higher sEPCR and similar mEPCR levels. Procr+/− and Procrs/+ mice generated similar levels of activated protein C (APC) upon thrombin infusion. They also exhibited a similar coagulant response upon factor Xa/phospholipid infusion. Only supraphysiologic levels of sEPCR could influence protein C activation and exaggerate the coagulant response. In conclusion, mEPCR, but not physiologically elevated sEPCR, regulated protein C activation. Procr heterozygosity results in a mild increase of thrombosis tendency and little influence on the response to endotoxin.

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Severe adult malaria is associated with specific PfEMP1 adhesion types and high parasite biomass

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1524294113 ◽

2016 ◽

Vol 113 (23) ◽

pp. E3270-E3279 ◽

Cited By ~ 47

Author(s):

Maria Bernabeu ◽

Samuel A. Danziger ◽

Marion Avril ◽

Marina Vaz ◽

Prasad H. Babar ◽

...

Keyword(s):

Severe Malaria ◽

Protein C ◽

Adult Population ◽

Activated Protein C ◽

Brain Endothelial Cells ◽

Endothelial Protein C Receptor ◽

Molecular Determinants ◽

Infected Adult ◽

Learning Analysis ◽

High Parasite

The interplay between cellular and molecular determinants that lead to severe malaria in adults is unexplored. Here, we analyzed parasite virulence factors in an infected adult population in India and investigated whether severe malaria isolates impair endothelial protein C receptor (EPCR), a protein involved in coagulation and endothelial barrier permeability. Severe malaria isolates overexpressed specific members of the Plasmodium falciparum var gene/PfEMP1 (P. falciparum erythrocyte membrane protein 1) family that bind EPCR, including DC8 var genes that have previously been linked to severe pediatric malaria. Machine learning analysis revealed that DC6- and DC8-encoding var transcripts in combination with high parasite biomass were the strongest indicators of patient hospitalization and disease severity. We found that DC8 CIDRα1 domains from severe malaria isolates had substantial differences in EPCR binding affinity and blockade activity for its ligand activated protein C. Additionally, even a low level of inhibition exhibited by domains from two cerebral malaria isolates was sufficient to interfere with activated protein C-barrier protective activities in human brain endothelial cells. Our findings demonstrate an interplay between parasite biomass and specific PfEMP1 adhesion types in the development of adult severe malaria, and indicate that low impairment of EPCR function may contribute to parasite virulence.

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Elucidating mechanisms of genetic cross-disease associations: an integrative approach implicates protein C as a causal pathway in arterial and venous diseases

10.1101/2020.03.16.20036822 ◽

2020 ◽

Cited By ~ 1

Author(s):

David Stacey ◽

Lingyan Chen ◽

Joanna M. M. Howson ◽

Amy M. Mason ◽

Stephen Burgess ◽

...

Keyword(s):

Cell Adhesion ◽

Protein C ◽

Activated Protein C ◽

Factor Vii ◽

Integrative Approach ◽

Genome Wide Association Studies ◽

Endothelial Protein C Receptor ◽

Venous Diseases ◽

Disease Associations ◽

Soluble Epcr

AbstractGenome-wide association studies have identified many individual genetic loci associated with multiple complex traits and common diseases. There are, however, few examples where the molecular basis of such pleiotropy has been elucidated. To address this challenge, we describe an integrative approach, focusing on the p.Ser219Gly (rs867186 A>G) variant in the PROCR gene (encoding the endothelial protein C receptor, EPCR), which has been associated with lower coronary artery disease (CAD) risk but higher venous thromboembolism (VTE) risk. In a phenome scan of 12 cardiometabolic diseases and 24 molecular factors, we found that PROCR-219Gly associated with higher plasma levels of zymogenic and activated protein C as well as coagulation factor VII. Using statistical colocalization and Mendelian randomization analyses, we uncovered shared genetic etiology across activated protein C, factor VII, CAD and VTE, identifying p.S219G as the likely causal variant at the locus. In a recall-by-genotype study of 52 healthy volunteers stratified by p.S219G, we detected 2.5-fold higher soluble EPCR levels and 1.2-fold higher protein C levels in plasma per effect allele, suggesting the allele induces EPCR shedding from the membrane of endothelial cells. Finally, in cell adhesion assays, we found that increasing concentrations of activated protein C, but not soluble EPCR, reduced leukocyte–endothelial cell adhesion, a marker for vascular inflammation. These results support a role for protein C as a causal factor in arterial and venous diseases, suggesting that PROCR-219Gly protects against CAD through anti-inflammatory mechanisms while it promotes VTE risk through pro-thrombotic mechanisms. Overall, our study illustrates a multi-modal approach that can help reveal molecular underpinnings of cross-disease associations.

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Factor V Leiden Is Associated with Repeated and Recurrent Unexplained Fetal Losses

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656060 ◽

1997 ◽

Vol 77 (05) ◽

pp. 0822-0824 ◽

Cited By ~ 145

Author(s):

Elvira Grandone ◽

Maurizio Margaglione ◽

Donatella Colaizzo ◽

Marina d'Addedda ◽

Giuseppe Cappucci ◽

...

Keyword(s):

Protein C ◽

Strong Association ◽

Activated Protein C ◽

Fetal Loss ◽

Factor V Leiden ◽

Factor V ◽

Significant Difference ◽

History Of ◽

Fv Leiden ◽

Caucasian Women

SummaryActivated protein C resistance (APCR) is responsible for most cases of familial thrombosis. The factor V missense mutation Arg506>Gln (FV Leiden) has been recognized as the commonest cause of this condition. Recently, it has been suggested that APCR is associated with second trimester fetal loss. We investigated the distribution of FV Leiden in a sample (n = 43) of Caucasian women with a history of two or more unexplained fetal losses. A group (n = 118) of parous women with uneventful pregnancies from the same ethnical background served as control. We found the mutation in 7 cases (16.28%) and 5 controls (4.24%; p = 0.011). A statistically significant difference between women with only early fetal loss vs those with late events (p = 0.04) was observed. Our data demonstrate a strong association between FV Leiden and fetal loss. Furthermore, they indicate that late events are more common in these patients.

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