bafilomycin-a1 and Sepsis

Autophagy plays distinct roles in apoptosis and the inflammatory process. Understanding the role of autophagy in sepsis-induced acute lung injury (ALI) may provide new insights into developing novel therapeutic strategies for this group of patients. The aim of this study was to investigate the regulation of autophagy in the septic lung and to use pharmacologic agents to modulate autophagy to study its functional significance.. Mice were subjected to cecal ligation and puncture (CLP) or a sham operation. At 1 hour after CLP, mice were treated with vehicle, activated protein C (APC), rapamycin, or bafilomycin A1. Mice were humanely killed at 4 or 24 hours after the operation or were observed for ≤ 7 days.. CLP induced a systemic inflammatory response and significantly decreased survival. In lung tissue, increased leukocyte infiltration, inflammation, and apoptosis were observed. In contrast, autophagy was suppressed after CLP such that the expression of LC3II, Atg5, and Rab7 were downregulated. Rapamycin activated autophagy, limited the CLP-induced proinflammatory response, and downregulated apoptotic activity after CLP. The administration of APC after CLP had an effect similar to that of rapamycin. Both medications significantly improved survival 7 days after CLP.. The downregulation of autophagy may lead to systemic inflammation and ALI after sepsis. The direct or indirect modification of autophagy using rapamycin or APC, respectively, resulted in improved survival. Enhancing or restoring autophagy early after sepsis seems to be a potential strategy for the treatment of sepsis-induced ALI.

Topics: Acute Lung Injury; Animals; Anti-Bacterial Agents; Apoptosis; Autophagy; Biomarkers; Blotting, Western; Cecum; Cells, Cultured; Cytokines; Humans; Immunohistochemistry; Ligation; Macrolides; Male; Mice; Mice, Inbred C3H; Protein C; Sepsis; Sirolimus

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.. 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.. 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.

Topics: Autophagy; Cells, Cultured; Humans; Macrolides; Neutrophils; Phosphatidylinositol 3-Kinase; Phosphoinositide-3 Kinase Inhibitors; Protein Transport; Sepsis; Thromboplastin