Autophagy mediates the delivery of thrombogenic tissue factor to neutrophil extracellular traps in human sepsis

Konstantinos Kambas; Ioannis Mitroulis; Eirini Apostolidou; Andreas Girod; Akrivi Chrysanthopoulou; Ioannis Pneumatikos; Panagiotis Skendros; Ioannis Kourtzelis; Maria Koffa; Ioannis Kotsianidis; Konstantinos Ritis

doi:10.1371/journal.pone.0045427

Autophagy mediates the delivery of thrombogenic tissue factor to neutrophil extracellular traps in human sepsis

Konstantinos Kambas, Ioannis Mitroulis, Eirini Apostolidou, Andreas Girod, Akrivi Chrysanthopoulou, Ioannis Pneumatikos, Panagiotis Skendros, Ioannis Kourtzelis, Maria Koffa, Ioannis Kotsianidis, Konstantinos Ritis

The Hull York Medical School

Research output: Contribution to journal › Article › peer-review

Abstract

BACKGROUND: Sepsis is associated with systemic inflammatory responses and induction of coagulation system. Neutrophil extracellular traps (NETs) constitute an antimicrobial mechanism, recently implicated in thrombosis via platelet entrapment and aggregation.

METHODOLOGY/PRINCIPAL FINDINGS: In this study, we demonstrate for the first time the localization of thrombogenic tissue factor (TF) in NETs released by neutrophils derived from patients with gram-negative sepsis and normal neutrophils treated with either serum from septic patients or inflammatory mediators involved in the pathogenesis of sepsis. Localization of TF in acidified autophagosomes was observed during this process, as indicated by positive LC3B and LysoTracker staining. Moreover, phosphatidylinositol 3-kinase inhibition with 3-MA or inhibition of endosomal acidification with bafilomycin A1 hindered the release of TF-bearing NETs. TF present in NETs induced thrombin generation in culture supernatants, which further resulted in protease activated receptor-1 signaling.

CONCLUSIONS/SIGNIFICANCE: This study demonstrates the involvement of autophagic machinery in the extracellular delivery of TF in NETs and the subsequent activation of coagulation cascade, providing evidence for the implication of this process in coagulopathy and inflammatory response in sepsis.

Original language	English
Pages (from-to)	e45427
Journal	PLoS ONE
Volume	7
Issue number	9
DOIs	https://doi.org/10.1371/journal.pone.0045427
Publication status	Published - 2012

Keywords

Autophagy/drug effects
Cells, Cultured
Humans
Macrolides/pharmacology
Neutrophils/metabolism
Phosphatidylinositol 3-Kinase/metabolism
Phosphoinositide-3 Kinase Inhibitors
Protein Transport/drug effects
Sepsis/metabolism
Thromboplastin/metabolism

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10.1371/journal.pone.0045427

Cite this

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title = "Autophagy mediates the delivery of thrombogenic tissue factor to neutrophil extracellular traps in human sepsis",

abstract = "BACKGROUND: Sepsis is associated with systemic inflammatory responses and induction of coagulation system. Neutrophil extracellular traps (NETs) constitute an antimicrobial mechanism, recently implicated in thrombosis via platelet entrapment and aggregation.METHODOLOGY/PRINCIPAL FINDINGS: In this study, we demonstrate for the first time the localization of thrombogenic tissue factor (TF) in NETs released by neutrophils derived from patients with gram-negative sepsis and normal neutrophils treated with either serum from septic patients or inflammatory mediators involved in the pathogenesis of sepsis. Localization of TF in acidified autophagosomes was observed during this process, as indicated by positive LC3B and LysoTracker staining. Moreover, phosphatidylinositol 3-kinase inhibition with 3-MA or inhibition of endosomal acidification with bafilomycin A1 hindered the release of TF-bearing NETs. TF present in NETs induced thrombin generation in culture supernatants, which further resulted in protease activated receptor-1 signaling.CONCLUSIONS/SIGNIFICANCE: This study demonstrates the involvement of autophagic machinery in the extracellular delivery of TF in NETs and the subsequent activation of coagulation cascade, providing evidence for the implication of this process in coagulopathy and inflammatory response in sepsis.",

keywords = "Autophagy/drug effects, Cells, Cultured, Humans, Macrolides/pharmacology, Neutrophils/metabolism, Phosphatidylinositol 3-Kinase/metabolism, Phosphoinositide-3 Kinase Inhibitors, Protein Transport/drug effects, Sepsis/metabolism, Thromboplastin/metabolism",

author = "Konstantinos Kambas and Ioannis Mitroulis and Eirini Apostolidou and Andreas Girod and Akrivi Chrysanthopoulou and Ioannis Pneumatikos and Panagiotis Skendros and Ioannis Kourtzelis and Maria Koffa and Ioannis Kotsianidis and Konstantinos Ritis",

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doi = "10.1371/journal.pone.0045427",

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T1 - Autophagy mediates the delivery of thrombogenic tissue factor to neutrophil extracellular traps in human sepsis

AU - Kambas, Konstantinos

AU - Mitroulis, Ioannis

AU - Apostolidou, Eirini

AU - Girod, Andreas

AU - Chrysanthopoulou, Akrivi

AU - Pneumatikos, Ioannis

AU - Skendros, Panagiotis

AU - Kourtzelis, Ioannis

AU - Koffa, Maria

AU - Kotsianidis, Ioannis

AU - Ritis, Konstantinos

PY - 2012

Y1 - 2012

N2 - BACKGROUND: Sepsis is associated with systemic inflammatory responses and induction of coagulation system. Neutrophil extracellular traps (NETs) constitute an antimicrobial mechanism, recently implicated in thrombosis via platelet entrapment and aggregation.METHODOLOGY/PRINCIPAL FINDINGS: In this study, we demonstrate for the first time the localization of thrombogenic tissue factor (TF) in NETs released by neutrophils derived from patients with gram-negative sepsis and normal neutrophils treated with either serum from septic patients or inflammatory mediators involved in the pathogenesis of sepsis. Localization of TF in acidified autophagosomes was observed during this process, as indicated by positive LC3B and LysoTracker staining. Moreover, phosphatidylinositol 3-kinase inhibition with 3-MA or inhibition of endosomal acidification with bafilomycin A1 hindered the release of TF-bearing NETs. TF present in NETs induced thrombin generation in culture supernatants, which further resulted in protease activated receptor-1 signaling.CONCLUSIONS/SIGNIFICANCE: This study demonstrates the involvement of autophagic machinery in the extracellular delivery of TF in NETs and the subsequent activation of coagulation cascade, providing evidence for the implication of this process in coagulopathy and inflammatory response in sepsis.

AB - BACKGROUND: Sepsis is associated with systemic inflammatory responses and induction of coagulation system. Neutrophil extracellular traps (NETs) constitute an antimicrobial mechanism, recently implicated in thrombosis via platelet entrapment and aggregation.METHODOLOGY/PRINCIPAL FINDINGS: In this study, we demonstrate for the first time the localization of thrombogenic tissue factor (TF) in NETs released by neutrophils derived from patients with gram-negative sepsis and normal neutrophils treated with either serum from septic patients or inflammatory mediators involved in the pathogenesis of sepsis. Localization of TF in acidified autophagosomes was observed during this process, as indicated by positive LC3B and LysoTracker staining. Moreover, phosphatidylinositol 3-kinase inhibition with 3-MA or inhibition of endosomal acidification with bafilomycin A1 hindered the release of TF-bearing NETs. TF present in NETs induced thrombin generation in culture supernatants, which further resulted in protease activated receptor-1 signaling.CONCLUSIONS/SIGNIFICANCE: This study demonstrates the involvement of autophagic machinery in the extracellular delivery of TF in NETs and the subsequent activation of coagulation cascade, providing evidence for the implication of this process in coagulopathy and inflammatory response in sepsis.

KW - Autophagy/drug effects

KW - Cells, Cultured

KW - Humans

KW - Macrolides/pharmacology

KW - Neutrophils/metabolism

KW - Phosphatidylinositol 3-Kinase/metabolism

KW - Phosphoinositide-3 Kinase Inhibitors

KW - Protein Transport/drug effects

KW - Sepsis/metabolism

KW - Thromboplastin/metabolism

U2 - 10.1371/journal.pone.0045427

DO - 10.1371/journal.pone.0045427

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JF - PLoS ONE

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