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.
  
  
  RESULTS
  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
  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.
authors.affiliation: First Department of Internal Medicine, Democritus University of Thrace, University General Hospital of Alexandroupolis, Alexandroupolis, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kambas
authors.forename: Ioannis
authors.initials: I
authors.lastname: Mitroulis
authors.forename: Eirini
authors.initials: E
authors.lastname: Apostolidou
authors.forename: Andreas
authors.initials: A
authors.lastname: Girod
authors.forename: Akrivi
authors.initials: A
authors.lastname: Chrysanthopoulou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Pneumatikos
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Skendros
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kourtzelis
authors.forename: Maria
authors.initials: M
authors.lastname: Koffa
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kotsianidis
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Ritis
mesh_terms: D001343:Autophagy / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D006801:Humans; D018942:Macrolides / Q000494:pharmacology; D009504:Neutrophils / Q000378:metabolism*; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D018805:Sepsis / Q000378:metabolism*; D013925:Thromboplastin / Q000378:metabolism*
chemical_list: D018942:Macrolides; D000081082:Phosphoinositide-3 Kinase Inhibitors; C040929:bafilomycin A1; D013925:Thromboplastin; D058539:Phosphatidylinositol 3-Kinase