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

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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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

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

10.21203/rs.2.9986/v1 ◽

2019 ◽

Author(s):

Lin Yang ◽

Ruilian Xin ◽

Shanchun Guo ◽

Mingli Liu

Keyword(s):

Severe Malaria ◽

Protein C ◽

Meta Analysis ◽

Activated Protein C ◽

Intercellular Adhesion Molecule ◽

Healthy Individuals ◽

Endothelial Protein C Receptor ◽

Intercellular Adhesion Molecule 1 ◽

Significant Difference ◽

Soluble Epcr

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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The Severity of Plasmodium falciparum Infection Is Associated with Transcript Levels of var Genes Encoding Endothelial Protein C Receptor-Binding P. falciparum Erythrocyte Membrane Protein 1

Infection and Immunity ◽

10.1128/iai.00841-16 ◽

2017 ◽

Vol 85 (4) ◽

Cited By ~ 39

Author(s):

Sixbert I. Mkumbaye ◽

Christian W. Wang ◽

Eric Lyimo ◽

Jakob S. Jespersen ◽

Alphaxard Manjurano ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Membrane Protein ◽

Severe Malaria ◽

Erythrocyte Membrane ◽

Protein C ◽

Transcript Level ◽

Endothelial Protein C Receptor ◽

Transcript Levels ◽

Content Type ◽

Erythrocyte Membrane Protein

ABSTRACT By attaching infected erythrocytes to the vascular lining, Plasmodium falciparum parasites leave blood circulation and avoid splenic clearance. This sequestration is central to pathogenesis. Severe malaria is associated with parasites expressing an antigenically distinct P. falciparum erythrocyte membrane protein 1 (PfEMP1) subset mediating binding to endothelial receptors. Previous studies indicate that PfEMP1 adhesins with so-called CIDRα1 domains capable of binding endothelial protein C receptor (EPCR) constitute the PfEMP1 subset associated with severe pediatric malaria. To analyze the relative importance of different subtypes of CIDRα1 domains, we compared Pfemp1 transcript levels in children with severe malaria (including 9 fatal and 114 surviving cases), children hospitalized with uncomplicated malaria (n = 42), children with mild malaria not requiring hospitalization (n = 10), and children with parasitemia and no ongoing fever (n = 12). High levels of transcripts encoding EPCR-binding PfEMP1 were found in patients with symptomatic infections, and the abundance of these transcripts increased with disease severity. The compositions of CIDRα1 subtype transcripts varied markedly between patients, and none of the subtypes were dominant. Transcript-level analyses targeting other domain types indicated that subtypes of DBLβ or DBLζ domains might mediate binding phenomena that, in conjunction with EPCR binding, could contribute to pathogenesis. These observations strengthen the rationale for targeting the PfEMP1-EPCR interaction by vaccines and adjunctive therapies. Interventions should target EPCR binding of all CIDRα1 subtypes.

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Association of the endothelial protein C receptor (PROCR) rs867186-G allele with protection from severe malaria

Malaria Journal ◽

10.1186/1475-2875-13-105 ◽

2014 ◽

Vol 13 (1) ◽

pp. 105 ◽

Cited By ~ 19

Author(s):

Izumi Naka ◽

Jintana Patarapotikul ◽

Hathairad Hananantachai ◽

Hiroo Imai ◽

Jun Ohashi

Keyword(s):

Severe Malaria ◽

Protein C ◽

Endothelial Protein C Receptor

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Severe malaria is associated with parasite binding to endothelial protein C receptor

Nature ◽

10.1038/nature12216 ◽

2013 ◽

Vol 498 (7455) ◽

pp. 502-505 ◽

Cited By ~ 314

Author(s):

Louise Turner ◽

Thomas Lavstsen ◽

Sanne S. Berger ◽

Christian W. Wang ◽

Jens E. V. Petersen ◽

...

Keyword(s):

Severe Malaria ◽

Protein C ◽

Endothelial Protein C Receptor

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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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Endothelial protein C receptor polymorphisms and risk of sepsis in a Chinese population

Journal of International Medical Research ◽

10.1177/0300060516686496 ◽

2017 ◽

Vol 45 (2) ◽

pp. 504-513 ◽

Cited By ~ 1

Author(s):

Yanbing Liang ◽

Xia Huang ◽

Yujie Jiang ◽

Yueqiu Qin ◽

Dingwei Peng ◽

...

Keyword(s):

Dna Sequencing ◽

Gene Polymorphisms ◽

Chinese Population ◽

Protein C ◽

Endothelial Protein C Receptor ◽

Male And Female ◽

Genotype Frequencies ◽

Increased Risk ◽

Relationship Of ◽

Soluble Epcr

Objective To examine the potential relationship of EPCR polymorphisms and the risk of sepsis in a Chinese population. Methods Snapshot SNP genotyping assays and DNA sequencing methods were used to detect polymorphisms of the EPCR gene, rs2069948C/T (2532C/T) and rs867186A/G (6936A/G), in 64 patients with sepsis and in 113 controls. Soluble EPCR (sEPCR) was measured by ELISA. Results There were significant differences in the allele and genotype frequencies of EPCR gene rs2069948C/T and allele frequencies of rs867186A/G between male and female patients and controls. Females carrying rs2069948 C/T genotype or T allele and males carrying rs867186 A allele were associated with a significantly increased risk of sepsis. Plasma sEPCR levels of sepsis patients were higher than controls and showed no correlation with EPCR gene polymorphisms. Conclusions EPCR polymorphisms may be associated with increased risk of sepsis, but this has no effect on the release of sEPCR in patients with sepsis.

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