Abstract
Objective- Activation of coagulation FXI (factor XI) by FXIIa (activated factor XII) is a prothrombotic process. The endothelium is known to play an antithrombotic role by limiting thrombin generation and platelet activation. It is unknown whether the antithrombotic role of the endothelium includes sequestration of FXIa (activated factor XI) activity. This study aims to determine the role of endothelial cells (ECs) in the regulation of the intrinsic pathway of coagulation. Approach and Results- Using a chromogenic assay, we observed that human umbilical veins ECs selectively blocked FXIa yet supported kallikrein and FXIIa activity. Western blotting and mass spectrometry analyses revealed that FXIa formed a complex with endothelial PAI-1 (plasminogen activator inhibitor-1). Blocking endothelial PAI-1 increased the cleavage of a chromogenic substrate by FXIa and the capacity of FXIa to promote fibrin formation in plasma. Western blot and immunofluorescence analyses showed that FXIa-PAI-1 complexes were either released into the media or trafficked to the early and late endosomes and lysosomes of ECs. When baboons were challenged with Staphylococcus aureus to induce a prothrombotic phenotype, an increase in circulating FXIa-PAI-1 complex levels was detected by ELISA within 2 to 8 hours postchallenge. Conclusions- PAI-1 forms a complex with FXIa on ECs, blocking its activity and inducing the clearance and degradation of FXIa. Circulating FXIa-PAI-1 complexes were detected in a baboon model of S. aureus sepsis. Although ECs support kallikrein and FXIIa activity, inhibition of FXIa by ECs may promote the clearance of intravascular FXIa. Visual Overview- An online visual overview is available for this article.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1390-1401 |
| Number of pages | 12 |
| Journal | Arteriosclerosis, thrombosis, and vascular biology |
| Volume | 39 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 1 2019 |
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Keywords
- endothelium
- fibrin
- kallikrein
- platelet activation
- thrombin
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
Cite this
Endothelial PAI-1 (Plasminogen Activator Inhibitor-1) Blocks the Intrinsic Pathway of Coagulation, Inducing the Clearance and Degradation of FXIa (Activated Factor XI). / Puy, Cristina; Ngo, Anh T.P.; Pang, Jiaqing; Keshari, Ravi S.; Hagen, Matthew W.; Hinds, Monica; Gailani, David; Gruber, Andras; Lupu, Florea; McCarty, Owen.
In: Arteriosclerosis, thrombosis, and vascular biology, Vol. 39, No. 7, 01.07.2019, p. 1390-1401.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Endothelial PAI-1 (Plasminogen Activator Inhibitor-1) Blocks the Intrinsic Pathway of Coagulation, Inducing the Clearance and Degradation of FXIa (Activated Factor XI)
AU - Puy, Cristina
AU - Ngo, Anh T.P.
AU - Pang, Jiaqing
AU - Keshari, Ravi S.
AU - Hagen, Matthew W.
AU - Hinds, Monica
AU - Gailani, David
AU - Gruber, Andras
AU - Lupu, Florea
AU - McCarty, Owen
PY - 2019/7/1
Y1 - 2019/7/1
N2 - Objective- Activation of coagulation FXI (factor XI) by FXIIa (activated factor XII) is a prothrombotic process. The endothelium is known to play an antithrombotic role by limiting thrombin generation and platelet activation. It is unknown whether the antithrombotic role of the endothelium includes sequestration of FXIa (activated factor XI) activity. This study aims to determine the role of endothelial cells (ECs) in the regulation of the intrinsic pathway of coagulation. Approach and Results- Using a chromogenic assay, we observed that human umbilical veins ECs selectively blocked FXIa yet supported kallikrein and FXIIa activity. Western blotting and mass spectrometry analyses revealed that FXIa formed a complex with endothelial PAI-1 (plasminogen activator inhibitor-1). Blocking endothelial PAI-1 increased the cleavage of a chromogenic substrate by FXIa and the capacity of FXIa to promote fibrin formation in plasma. Western blot and immunofluorescence analyses showed that FXIa-PAI-1 complexes were either released into the media or trafficked to the early and late endosomes and lysosomes of ECs. When baboons were challenged with Staphylococcus aureus to induce a prothrombotic phenotype, an increase in circulating FXIa-PAI-1 complex levels was detected by ELISA within 2 to 8 hours postchallenge. Conclusions- PAI-1 forms a complex with FXIa on ECs, blocking its activity and inducing the clearance and degradation of FXIa. Circulating FXIa-PAI-1 complexes were detected in a baboon model of S. aureus sepsis. Although ECs support kallikrein and FXIIa activity, inhibition of FXIa by ECs may promote the clearance of intravascular FXIa. Visual Overview- An online visual overview is available for this article.
AB - Objective- Activation of coagulation FXI (factor XI) by FXIIa (activated factor XII) is a prothrombotic process. The endothelium is known to play an antithrombotic role by limiting thrombin generation and platelet activation. It is unknown whether the antithrombotic role of the endothelium includes sequestration of FXIa (activated factor XI) activity. This study aims to determine the role of endothelial cells (ECs) in the regulation of the intrinsic pathway of coagulation. Approach and Results- Using a chromogenic assay, we observed that human umbilical veins ECs selectively blocked FXIa yet supported kallikrein and FXIIa activity. Western blotting and mass spectrometry analyses revealed that FXIa formed a complex with endothelial PAI-1 (plasminogen activator inhibitor-1). Blocking endothelial PAI-1 increased the cleavage of a chromogenic substrate by FXIa and the capacity of FXIa to promote fibrin formation in plasma. Western blot and immunofluorescence analyses showed that FXIa-PAI-1 complexes were either released into the media or trafficked to the early and late endosomes and lysosomes of ECs. When baboons were challenged with Staphylococcus aureus to induce a prothrombotic phenotype, an increase in circulating FXIa-PAI-1 complex levels was detected by ELISA within 2 to 8 hours postchallenge. Conclusions- PAI-1 forms a complex with FXIa on ECs, blocking its activity and inducing the clearance and degradation of FXIa. Circulating FXIa-PAI-1 complexes were detected in a baboon model of S. aureus sepsis. Although ECs support kallikrein and FXIIa activity, inhibition of FXIa by ECs may promote the clearance of intravascular FXIa. Visual Overview- An online visual overview is available for this article.
KW - endothelium
KW - fibrin
KW - kallikrein
KW - platelet activation
KW - thrombin
UR - http://www.scopus.com/inward/record.url?scp=85068862642&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85068862642&partnerID=8YFLogxK
U2 - 10.1161/ATVBAHA.119.312619
DO - 10.1161/ATVBAHA.119.312619
M3 - Article
VL - 39
SP - 1390
EP - 1401
JO - Arteriosclerosis, Thrombosis, and Vascular Biology
JF - Arteriosclerosis, Thrombosis, and Vascular Biology
SN - 1079-5642
IS - 7
ER -