Reactive oxygen species-induced activation of ERK and p38 MAPK mediates PMA-induced NETs release from human neutrophils

2013 ◽  
Vol 114 (3) ◽  
pp. 532-540 ◽  
Author(s):  
Ravi S. Keshari ◽  
Anupam Verma ◽  
Manoj K. Barthwal ◽  
Madhu Dikshit
Keyword(s):  
Reactive Oxygen Species ◽  
P38 Mapk ◽  
Reactive Oxygen ◽  
Human Neutrophils ◽  
Oxygen Species

Abstract 097: Recombinant Human Erythropoietin Prevents Reactive Oxygen Species - Induced Apoptosis Via Akt and p38 MAPK Pathway During Hypoxia/ Reperfusion Injury

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Asiya Parvin Allaudeen ◽  
Ajay Devendran ◽  
John E Baker ◽  
Anuradha Dhanasekaran
Keyword(s):  
Reactive Oxygen Species ◽  
P38 Mapk ◽  
Caspase 3 ◽  
Mapk Pathway ◽  
Intact Cell ◽  
Reactive Oxygen ◽  
Protective Role ◽  
Oxygen Species ◽  
Human Erythropoietin ◽  
In Cells

Erythropoietin (EPO) is a cytokine produced primarily in the kidney that is essential for red blood cell production. Apart from playing a role in hematopoiesis, EPO also has a protective role in heart myocytes, ovarian, glial cells brain and retinal diseases. In this study we observed that recombinant human EPO (rhEPO) reduces Hypoxia/ Reperfusion (H/R) injury by virtue of its effect on EPO receptor prosurvival signaling pathway, which ultimately leads to reduced expression of apoptotic proteins and increased survival of cardiomyocytes. H9C2 cells were exposed to H/R with or without pretreatment using 10, 15 and 20 U/ml of rhEPO. We determined viability using MTT, nuclear fragmentation by Hoechst staining, apoptotic nuclei by Acridine orange and Ethidium bromide, Reactive Oxygen Species (ROS) by Dicholorofluoresin Diacetate and activity of late apoptotic protease, Caspase-3 by colorimetric Caspase-3 assay. The expression of mitochondrial superoxide dismutase (MnSOD) by RT-PCR and Western blot, phospho-Akt and p38 MAPK by Confocal microscopy were analyzed. Cell viability is increased in cells pretreated with rhEPO compared to cell exposed to H/R. Cells subjected to H/R showed early apoptotic and late apoptotic cells but showed normal nuclei with intact cell membrane in cells pretreated with rhEPO. Intracellular production of ROS and Caspase-3 activity was decreased in cells pretreated with rhEPO compared to cells exposed to H/R. The expression of MnSOD RNA and protein was up-regulated in response to rhEPO, but not in H/R. The phosphorylative activation of Akt, p38MAPK progressively diminished during H/R but increased in rhEPO pretreated cells. We show that rhEPO prevents apoptosis in cardiomyocytes, subjected to H/R injury via phosphorylation of Akt and p38MAPK. These results it is hoped would help us distinguish the cell signaling pathways involved in cardioprotection and thus would open new avenues in cardiovascular therapy.

scholarly journals Simultaneous use of electrochemistry and chemiluminescence to detect reactive oxygen species produced by human neutrophils

2008 ◽  
Vol 32 (12) ◽  
pp. 1486-1496 ◽  
Author(s):  
Sergey Shleev ◽  
Jonas Wetterö ◽  
Karl-Eric Magnusson ◽  
Tautgirdas Ruzgas
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Human Neutrophils ◽  
Oxygen Species ◽  
Simultaneous Use

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.

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