title: Intermittent Hypoxia Affects the Spontaneous Differentiation In Vitro of Human Neutrophils into Long-Lived Giant Phagocytes.
abstract: Previously we identified, for the first time, a new small-size subset of neutrophil-derived giant phagocytes (Gϕ) which spontaneously develop in vitro without additional growth factors or cytokines. Gϕ are CD66b(+)/CD63(+)/MPO(+)/LC3B(+) and are characterized by extended lifespan, large phagolysosomes, active phagocytosis, and reactive oxygen species (ROS) production, and autophagy largely controls their formation. Hypoxia, and particularly hypoxia/reoxygenation, is a prominent feature of many pathological processes. Herein we investigated Gϕ formation by applying various hypoxic conditions. Chronic intermittent hypoxia (IH) (29 cycles/day for 5 days) completely abolished Gϕ formation, while acute IH had dose-dependent effects. Exposure to 24 h (56 IH cycles) decreased their size, yield, phagocytic ability, autophagy, mitophagy, and gp91-phox/p22-phox expression, whereas under 24 h sustained hypoxia (SH) the size and expression of LC3B and gp91-phox/p22-phox resembled Gϕ formed in normoxia. Diphenyl iodide (DPI), a NADPH oxidase inhibitor, as well as the PI3K/Akt and autophagy inhibitor LY294002 abolished Gϕ formation at all oxygen conditions. However, the potent antioxidant, N-acetylcysteine (NAC) abrogated the effects of IH by inducing large CD66b(+)/LC3B(+) Gϕ and increased both NADPH oxidase expression and phagocytosis. These findings suggest that NADPH oxidase, autophagy, and the PI3K/Akt pathway are involved in Gϕ development.
authors.affiliation: The Lloyd Rigler Sleep Apnea Research Laboratory, Unit of Anatomy and Cell Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 31096 Haifa, Israel.
authors.forename: Larissa
authors.initials: L
authors.lastname: Dyugovskaya
authors.affiliation: The Lloyd Rigler Sleep Apnea Research Laboratory, Unit of Anatomy and Cell Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 31096 Haifa, Israel.
authors.forename: Slava
authors.initials: S
authors.lastname: Berger
authors.affiliation: The Lloyd Rigler Sleep Apnea Research Laboratory, Unit of Anatomy and Cell Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 31096 Haifa, Israel.
authors.forename: Andrey
authors.initials: A
authors.lastname: Polyakov
authors.affiliation: The Lloyd Rigler Sleep Apnea Research Laboratory, Unit of Anatomy and Cell Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 31096 Haifa, Israel.
authors.forename: Peretz
authors.initials: P
authors.lastname: Lavie
authors.affiliation: The Lloyd Rigler Sleep Apnea Research Laboratory, Unit of Anatomy and Cell Biology, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 31096 Haifa, Israel.
authors.forename: Lena
authors.initials: L
authors.lastname: Lavie
mesh_terms: D000328:Adult; D000943:Antigens, Differentiation / Q000378:metabolism; D002454:Cell Differentiation; D015687:Cell Hypoxia; D002478:Cells, Cultured; D005260:Female; D015726:Giant Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008297:Male; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D000943:Antigens, Differentiation