Mac-1 Directly Binds to the Endothelial Protein C-Receptor: A Link between the Protein C Anticoagulant Pathway and Inflammation?

Fink, Katrin; Busch, Hans-Joerg; Bourgeois, Natascha; Schwarz, M.; Wolf, Dennis; Zirlik, Andreas; Peter, Karlheinz; Bode, Christoph; Mühlen, Constantin von zur

doi:10.1371/journal.pone.0053103

Cited by 23 publications

(20 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…10). EPCR and ␤ integrins expressed on neutrophils are known to bind APC resulting in a reduction in migration (14,15,18), and our results now suggest a role for the receptors EPCR and Mac-1 in APC-mediated inhibition of NETosis. Based on molecular studies with endothelial cells and podocytes, APC ligates EPCR and cleaves PAR1 and PAR3 at noncanonical residues differing from the thrombin cleavage sites (19,24).…”

Section: Discussionsupporting

confidence: 65%

Activated protein C inhibits neutrophil extracellular trap formation in vitro and activation in vivo

Healy

Puy

Fernández

et al. 2017

Journal of Biological Chemistry

View full text Add to dashboard Cite

Activated protein C (APC) is a multifunctional serine protease with anticoagulant, cytoprotective, and anti-inflammatory activities. In addition to the cytoprotective effects of APC on endothelial cells, podocytes, and neurons, APC cleaves and detoxifies extracellular histones, a major component of neutrophil extracellular traps (NETs). NETs promote pathogen clearance but also can lead to thrombosis; the pathways that negatively regulate NETosis are largely unknown. Thus, we studied whether APC is capable of directly inhibiting NETosis via receptor-mediated cell signaling mechanisms. Here, by quantifying extracellular DNA or myeloperoxidase, we demonstrate that APC binds human leukocytes and prevents activated platelet supernatant or phorbol 12-myristate 13-acetate (PMA) from inducing NETosis. Of note, APC proteolytic activity was required for inhibiting NETosis. Moreover, antibodies against the neutrophil receptors endothelial protein C receptor (EPCR), protease-activated receptor 3 (PAR3), and macrophage-1 antigen (Mac-1) blocked APC inhibition of NETosis. Select mutations in the Gla and protease domains of recombinant APC caused a loss of NETosis. Interestingly, pretreatment of neutrophils with APC prior to induction of NETosis inhibited platelet adhesion to NETs. Lastly, in a nonhuman primate model of -induced sepsis, pretreatment of animals with APC abrogated release of myeloperoxidase from neutrophils, a marker of neutrophil activation. These findings suggest that the anti-inflammatory function of APC at therapeutic concentrations may include the inhibition of NETosis in an EPCR-, PAR3-, and Mac-1-dependent manner, providing additional mechanistic insight into the diverse functions of neutrophils and APC in disease states including sepsis.

show abstract

Section: Discussionsupporting

confidence: 65%

Activated protein C inhibits neutrophil extracellular trap formation in vitro and activation in vivo

Healy

Puy

Fernández

et al. 2017

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…The ability of soluble (s)EPCR to bind Mac-1 on neutrophils indirectly through its association with PR3 26 suggests that EPCR may interfere with neutrophil adhesion to activated endothelium. 69 However, the ability of sEPCR and cell-associated EPCR to bind Mac1 directly 28 suggests that the role of EPCR in leukocyte adhesion may vary and would be dependent on the ratio of sEPCR vs cell surface EPCR.…”

mentioning

confidence: 99%

Endothelial cell protein C receptor: a multiliganded and multifunctional receptor

Rao

Esmon

Pendurthi

2014

Blood

168

109

View full text Add to dashboard Cite

Endothelial cell protein C receptor (EPCR) was first identified and isolated as a cellular receptor for protein C on endothelial cells. EPCR plays a crucial role in the protein C anticoagulant pathway by promoting protein C activation. In the last decade, EPCR has received wide attention after it was discovered to play a key role in mediating activated protein C (APC)-induced cytoprotective effects, including antiapoptotic, anti-inflammatory, and barrier stabilization. APC elicits cytoprotective signaling through activation of protease activated receptor-1 (PAR1). Understanding how EPCR-APC induces cytoprotective effects through activation of PAR1, whose activation by thrombin is known to induce a proinflammatory response, has become a major research focus in the field. Recent studies also discovered additional ligands for EPCR, which include factor VIIa, Plasmodium falciparum erythrocyte membrane protein, and a specific variant of the T-cell receptor. These observations open unsuspected new roles for EPCR in hemostasis, malaria pathogenesis, innate immunity, and cancer. Future research on these new discoveries will undoubtedly expand our understanding of the role of EPCR in normal physiology and disease, as well as provide novel insights into mechanisms for EPCR multifunctionality. Comprehensive understanding of EPCR may lead to development of novel therapeutic modalities in treating hemophilia, inflammation, cerebral malaria, and cancer.

show abstract

“…In this regard, Fink et al showed that soluble EPCR mediates monocyte adhesion by direct binding to Mac-1, an interaction which might possibly involve RAGE too [62]. Notably, and in contrast to the study of Fink et al ., the majority of recruited leukocytes in our experimental inflammation models are neutrophils [8], [40]–[43].…”

Section: Discussionmentioning

confidence: 86%

RAGE Controls Activation and Anti-Inflammatory Signalling of Protein C

et al. 2014

View full text Add to dashboard Cite

AimsThe receptor for advanced glycation endproducts, RAGE, is a multiligand receptor and NF-κB activator leading to perpetuation of inflammation. We investigated whether and how RAGE is involved in mediation of anti-inflammatory properties of protein C.Methods and ResultsWe analyzed the effect of protein C on leukocyte adhesion and transmigration in WT- and RAGE-deficient mice using intravital microscopy of cremaster muscle venules during trauma- and TNFα-induced inflammation. Both, protein C (PC, Ceprotin, 100 U/kg) and activated protein C (aPC, 24 µg/kg/h) treatment significantly inhibited leukocyte adhesion in WT mice in these inflammation models. The impaired leukocyte adhesion after trauma-induced inflammation in RAGE knockout mice could not be further reduced by PC and aPC. After TNFα-stimulation, however, aPC but not PC treatment effectively blocked leukocyte adhesion in these mice. Consequently, we asked whether RAGE is involved in PC activation. Since RAGE-deficient mice and endothelial cells showed insufficient PC activation, and since thrombomodulin (TM) and endothelial protein C receptor (EPCR) are reduced on the mRNA and protein level in RAGE deficient endothelial cells, an involvement of RAGE in TM-EPCR-dependent PC activation is likely. Moreover, TNFα-induced activation of MAPK and upregulation of ICAM-1 and VCAM-1 are reduced both in response to aPC treatment and in the absence of RAGE. Thus, there seems to be interplay of the RAGE and the PC pathway in inflammation.ConclusionRAGE controls anti-inflammatory properties and activation of PC, which might involve EPCR and TM.

show abstract

Mac-1 Directly Binds to the Endothelial Protein C-Receptor: A Link between the Protein C Anticoagulant Pathway and Inflammation?

Cited by 23 publications

References 30 publications

Activated protein C inhibits neutrophil extracellular trap formation in vitro and activation in vivo

Activated protein C inhibits neutrophil extracellular trap formation in vitro and activation in vivo

Endothelial cell protein C receptor: a multiliganded and multifunctional receptor

RAGE Controls Activation and Anti-Inflammatory Signalling of Protein C

Contact Info

Product

Resources

About