Involvement of Caspases in Neutrophil Apoptosis: Regulation by Reactive Oxygen Species

Blood ◽  
1998 ◽  
Vol 92 (12) ◽  
pp. 4808-4818 ◽  
Author(s):  
Bengt Fadeel ◽  
Anders Åhlin ◽  
Jan-Inge Henter ◽  
Sten Orrenius ◽  
Mark B. Hampton
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Nadph Oxidase ◽  
Reactive Oxygen ◽  
Human Neutrophils ◽  
Neutrophil Apoptosis ◽  
Dependent Manner ◽  
Caspase Activity ◽  
Oxygen Species ◽  
Spontaneous Apoptosis

Abstract Human neutrophils have a short half-life and are believed to die by apoptosis or programmed cell death both in vivo and in vitro. We found that caspases are activated in a time-dependent manner in neutrophils undergoing spontaneous apoptosis, concomitant with other characteristic features of apoptotic cell death such as morphologic changes, phosphatidylserine (PS) exposure, and DNA fragmentation. The treatment of neutrophils with agonistic anti-Fas monoclonal antibodies (MoAbs) significantly accelerated this process. However, in cells treated with the potent neutrophil activator phorbol 12-myristate 13-acetate (PMA), caspase activity was only evident after pharmacologic inhibition of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Similarily, inhibition of the NADPH oxidase in constitutive and Fas/APO-1–triggered apoptosis resulted in increased rather than suppressed levels of caspase activity, suggesting that reactive oxygen species may prevent caspases from functioning optimally in these cells. Moreover, oxidants generated via the NADPH oxidase were essential for PS exposure during PMA-induced cell death, but not for neutrophils undergoing spontaneous apoptosis. We conclude that caspases are an important component of constitutive and Fas/APO-1–triggered neutrophil apoptosis. However, these redox sensitive enzymes are suppressed in activated neutrophils, and an alternate oxidant-dependent pathway is used to mediate PS exposure and neutrophil clearance under these conditions.

Involvement of Caspases in Neutrophil Apoptosis: Regulation by Reactive Oxygen Species

Blood ◽  
1998 ◽  
Vol 92 (12) ◽  
pp. 4808-4818 ◽  
Author(s):  
Bengt Fadeel ◽  
Anders Åhlin ◽  
Jan-Inge Henter ◽  
Sten Orrenius ◽  
Mark B. Hampton
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Nadph Oxidase ◽  
Reactive Oxygen ◽  
Human Neutrophils ◽  
Neutrophil Apoptosis ◽  
Dependent Manner ◽  
Caspase Activity ◽  
Oxygen Species ◽  
Spontaneous Apoptosis

Human neutrophils have a short half-life and are believed to die by apoptosis or programmed cell death both in vivo and in vitro. We found that caspases are activated in a time-dependent manner in neutrophils undergoing spontaneous apoptosis, concomitant with other characteristic features of apoptotic cell death such as morphologic changes, phosphatidylserine (PS) exposure, and DNA fragmentation. The treatment of neutrophils with agonistic anti-Fas monoclonal antibodies (MoAbs) significantly accelerated this process. However, in cells treated with the potent neutrophil activator phorbol 12-myristate 13-acetate (PMA), caspase activity was only evident after pharmacologic inhibition of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Similarily, inhibition of the NADPH oxidase in constitutive and Fas/APO-1–triggered apoptosis resulted in increased rather than suppressed levels of caspase activity, suggesting that reactive oxygen species may prevent caspases from functioning optimally in these cells. Moreover, oxidants generated via the NADPH oxidase were essential for PS exposure during PMA-induced cell death, but not for neutrophils undergoing spontaneous apoptosis. We conclude that caspases are an important component of constitutive and Fas/APO-1–triggered neutrophil apoptosis. However, these redox sensitive enzymes are suppressed in activated neutrophils, and an alternate oxidant-dependent pathway is used to mediate PS exposure and neutrophil clearance under these conditions.

scholarly journals The Role of NADPH Oxidase 1–Derived Reactive Oxygen Species in Paraquat-Mediated Dopaminergic Cell Death

2009 ◽  
Vol 11 (9) ◽  
pp. 2105-2118 ◽  
Author(s):  
Ana Clara Cristóvão ◽  
Dong-Hee Choi ◽  
Graça Baltazar ◽  
M. Flint Beal ◽  
Yoon-Seong Kim
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Nadph Oxidase ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Dopaminergic Cell ◽  
Nadph Oxidase 1

z-VAD-fmk augmentation of TNFα-stimulated neutrophil apoptosis is compound specific and does not involve the generation of reactive oxygen species

Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2970-2972 ◽  
Author(s):  
Andrew S. Cowburn ◽  
Jessica F. White ◽  
John Deighton ◽  
Sarah R. Walmsley ◽  
Edwin R. Chilvers
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Broad Spectrum ◽  
Reactive Oxygen ◽  
Cell Types ◽  
Ros Generation ◽  
Neutrophil Apoptosis ◽  
Oxygen Species ◽  
Caspase Inhibitor ◽  
Induced Apoptosis

Abstract In most cell types constitutive and ligand-induced apoptosis is a caspase-dependent process. In neutrophils, however, the broad-spectrum caspase inhibitor z-VAD-fmk enhances tumor necrosis factor-α (TNFα)-induced cell death, and this has been interpreted as evidence for caspase-dependent and -independent cell death pathways. Our aim was to determine the specificity of the effect of z-VAD-fmk in neutrophils and define the potential mechanism of action. While confirming that z-VAD-fmk (> 100 μM) enhances TNFα-induced neutrophil apoptosis, lower concentrations (1-30 μM) completely blocked TNFα-stimulated apoptosis. Boc-D-fmk, a similar broad-spectrum caspase inhibitor, and z-IETD-fmk, a selective caspase-8 inhibitor, caused a concentration-dependent inhibition of only TNFα-stimulated apoptosis. Moreover, the caspase-9 inhibitor, Ac-LEHD-cmk, had no effect on TNFα-induced apoptosis, and z-VAD-fmk and Boc-D-fmk inhibited TNFα-stimulated reactive oxygen species (ROS) generation. These data suggest that TNFα-induced apoptosis in neutrophils is fully caspase dependent and uses a mitochondrial-independent pathway and that the proapoptotic effects of z-VAD-fmk are compound specific and ROS independent.

scholarly journals P2X7 Receptor Activation Induces Reactive Oxygen Species Formation and Cell Death in Murine EOC13 Microglia

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Rachael Bartlett ◽  
Justin J. Yerbury ◽  
Ronald Sluyter
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Cell Line ◽  
Purinergic Receptor ◽  
Reactive Oxygen ◽  
Receptor Activation ◽  
Organic Cations ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Ros Formation

The P2X7 purinergic receptor is a ligand-gated cation channel expressed on leukocytes including microglia. This study aimed to determine if P2X7 activation induces the uptake of organic cations, reactive oxygen species (ROS) formation, and death in the murine microglial EOC13 cell line. Using the murine macrophage J774 cell line as a positive control, RT-PCR, immunoblotting, and immunolabelling established the presence of P2X7 in EOC13 cells. A cytofluorometric assay demonstrated that the P2X7 agonists adenosine-5′-triphosphate (ATP) and 2′(3′)-O-(4-benzoylbenzoyl) ATP induced ethidium+or YO-PRO-12+uptake into both cell lines. ATP induced ethidium+uptake into EOC13 cells in a concentration-dependent manner, with an EC50of~130 μM. The P2X7 antagonists Brilliant Blue G, A438079, AZ10606120, and AZ11645373 inhibited ATP-induced cation uptake into EOC13 cells by 75–100%. A cytofluorometric assay demonstrated that P2X7 activation induced ROS formation in EOC13 cells, via a mechanism independent of Ca2+influx and K+efflux. Cytofluorometric measurements of Annexin-V binding and 7AAD uptake demonstrated that P2X7 activation induced EOC13 cell death. The ROS scavenger N-acetyl-L-cysteine impaired both P2X7-induced EOC13 ROS formation and cell death, suggesting that ROS mediate P2X7-induced EOC13 death. In conclusion, P2X7 activation induces the uptake of organic cations, ROS formation, and death in EOC13 microglia.

Angiotensin II Mediates High Glucose-Induced TGF-β1 and Fibronectin Upregulation in HPMC through Reactive Oxygen Species

2005 ◽  
Vol 25 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Hyunjin Noh ◽  
Hunjoo Ha ◽  
Mi Ra Yu ◽  
Young Ok Kim ◽  
Ji Hye Kim ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Nadph Oxidase ◽  
Protein Expression ◽  
High Glucose ◽  
Reactive Oxygen ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Ang Ii ◽  
Fibronectin Expression ◽  
Tgf Β1

Objective To demonstrate the presence of an independent renin–angiotensin system (RAS) in the peritoneum and to determine the role of locally produced angiotensin (Ang) II in high glucose-induced upregulation of transforming growth factor (TGF)-β1 and fibronectin by human peritoneal mesothelial cells (HPMC). Methods In cultured HPMC, the expression of mRNAs for angiotensinogen, angiotensin-converting enzyme (ACE), Ang II type 1 receptor (AT1), and TGF-β1 was evaluated by real-time polymerase chain reaction; ACE, AT1, and fibronectin proteins by Western blot analysis; and Ang I, Ang II, and TGF-β1 proteins by ELISA. Dichlorofluorescein (DCF)-sensitive cellular reactive oxygen species (ROS) were measured by fluorometry. Results HPMC constitutively expressed all the components of RAS, and 50 mmol/L D-glucose (high glucose) significantly increased angiotensinogen, ACE, and AT1 mRNAs and ACE, AT1, and Ang II proteins. Ang II increased TGF-β1 and fibronectin protein expression and DCF-sensitive cellular ROS. Losartan prevented Ang II-induced increase in cellular ROS. Both losartan and captopril inhibited high glucose-induced upregulation of TGF-β1 and fibronectin expression in HPMC in a dose-dependent manner. Antioxidant catalase and NADPH oxidase inhibitor diphenyleneiodinium effectively inhibited Ang II-induced TGF-β1 and fibronectin protein expression. Conclusions The present data demonstrate that HPMC constitutively express RAS, that Ang II produced by HPMC mediates high glucose-induced upregulation of TGF-β1 and fibronectin expression, and that Ang II-induced TGF-β1 and fibronectin expression in HPMC is mediated by NADPH oxidase-dependent ROS. These data suggest that locally produced Ang II and ROS in the peritoneum may be potential therapeutic targets in peritoneal fibrosis during long-term peritoneal dialysis.

scholarly journals Antibody-induced nonapoptotic cell death in human lymphoma and leukemia cells is mediated through a novel reactive oxygen species-dependent pathway

Blood ◽  
2012 ◽  
Vol 119 (15) ◽  
pp. 3523-3533 ◽  
Author(s):  
Jamie Honeychurch ◽  
Waleed Alduaij ◽  
Mahsa Azizyan ◽  
Eleanor J. Cheadle ◽  
Helene Pelicano ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Nadph Oxidase ◽  
B Cell ◽  
Reactive Oxygen ◽  
Leukemia Cells ◽  
Oxygen Species ◽  
Type Ii ◽  
B Cell Malignancies ◽  
Anti Cd20

Abstract Monoclonal antibodies (mAbs) have revolutionized the treatment of B-cell malignancies. Although Fc-dependent mechanisms of mAb-mediated tumor clearance have been extensively studied, the ability of mAbs to directly evoke programmed cell death (PCD) in the target cell and the underlying mechanisms involved remain under-investigated. We recently demonstrated that certain mAbs (type II anti-CD20 and anti-HLA DR mAbs) potently evoked PCD through an actin-dependent, lysosome-mediated process. Here, we reveal that the induction of PCD by these mAbs, including the type II anti-CD20 mAb GA101 (obinutuzumab), directly correlates with their ability to produce reactive oxygen species (ROS) in human B-lymphoma cell lines and primary B-cell chronic lymphocytic leukemia cells. ROS scavengers abrogated mAb-induced PCD indicating that ROS are required for the execution of cell death. ROS were generated downstream of mAb-induced actin cytoskeletal reorganization and lysosome membrane permeabilization. ROS production was independent of mitochondria and unaffected by BCL-2 overexpression. Instead, ROS generation was mediated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. These findings provide further insights into a previously unrecognized role for NADPH oxidase-derived ROS in mediating nonapoptotic PCD evoked by mAbs in B-cell malignancies. This newly characterized cell death pathway may potentially be exploited to eliminate malignant cells, which are refractory to conventional chemotherapy and immunotherapy.

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