Synergistic inhibition of platelet function by NADPH oxidase inhibitors and clopidogrel

2021 ◽  
Vol 7 (2) ◽  
pp. 65-69
Author(s):  
ZETTY NADIA MOHD ZAIN
Keyword(s):  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Human Platelets ◽  
Calcium Mobilization ◽  
P2y12 Receptor ◽  
Activation Markers ◽  
Nadph Oxidase Activity ◽  
Nox Inhibitors ◽  
Ros Formation ◽  
Camp Levels

Previous studies have shown platelets play an important role in prothrombotic complications due to several factors such as hyperglycemia, oxidative stress, and hypercholesterolemia, which affected platelets reactivity. Platelets activation involves ADP stimulation via P2Y12 receptor, whereas reactive oxygen species (ROS) including superoxide anion and hydrogen peroxide (H2O2) produced by NADPH oxidase (Nox) act as the second messenger, which involved in platelets activation and may contribute to thrombus formation. The aim of the present study was to investigate the influence of Nox on the purinergic receptor (P2Y12 receptor) in activation of human platelets function stimulated by platelets agonist. This research explored the effects of Nox inhibitors and clopidogrel either alone or in combination, on various agonist-stimulated human platelets, including platelets aggregation and adhesion measured by modified LTA, expression of platelets activation markers, and calcium mobilization using flow cytometry, and ROS formation, NADPH oxidase activity, as well as cAMP levels by chemiluminescence assay. Taken together, findings from these experiments suggest that the combination of clopidogrel and Nox inhibitors synergistically reduced platelets aggregation, platelets adhesion, and expression of platelets activation marker during late activation, ROS formation, NADPH oxidase activity, calcium mobilization and increased cAMP levels in vitro. This combination showed that P2Y12receptor reactivity was influenced by the activation of NADPH oxidase. Thus, these data demonstrated a potential combination therapy to reduce the risk of thrombosis formation.  

scholarly journals Calcium mobilization and Rac1 activation are required for VCAM-1 (vascular cell adhesion molecule-1) stimulation of NADPH oxidase activity

2004 ◽  
Vol 378 (2) ◽  
pp. 539-547 ◽  
Author(s):  
Joan M. COOK-MILLS ◽  
Jacob D. JOHNSON ◽  
Tracy L. DEEM ◽  
Atsuo OCHI ◽  
Lei WANG ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Cell Adhesion Molecule ◽  
Calcium Mobilization ◽  
Vascular Cell Adhesion ◽  
Lymphocyte Migration ◽  
Nadph Oxidase Activity ◽  
Cell Adhesion Molecule 1 ◽  
Stimulation Of

VCAM-1 (vascular cell adhesion molecule-1) plays an important role in the regulation of inflammation in atherosclerosis, asthma, inflammatory bowel disease and transplantation. VCAM-1 activates endothelial cell NADPH oxidase, and this oxidase activity is required for VCAM-1-dependent lymphocyte migration. We reported previously that a mouse microvascular endothelial cell line promotes lymphocyte migration that is dependent on VCAM-1, but not on other known adhesion molecules. Here we have investigated the signalling mechanisms underlying VCAM-1 function. Lymphocyte binding to VCAM-1 on the endothelial cell surface activated an endothelial cell calcium flux that could be inhibited with anti-α4-integrin and mimicked by anti-VCAM-1-coated beads. VCAM-1 stimulation of calcium responses could be blocked by an inhibitor of intracellular calcium mobilization, a calcium channel inhibitor or a calcium chelator, resulting in the inhibition of NADPH oxidase activity. Addition of ionomycin overcame the calcium channel blocker suppression of VCAM-1-stimulated NADPH oxidase activity, but could not reverse the inhibitory effect imposed by intracellular calcium blockage, indicating that both intracellular and extracellular calcium mobilization are required for VCAM-1-mediated activation of NADPH oxidase. Furthermore, VCAM-1 specifically activated the Rho-family GTPase Rac1, and VCAM-1 activation of NADPH oxidase was blocked by a dominant negative Rac1. Thus VCAM-1 stimulates the mobilization of intracellular and extracellular calcium and Rac1 activity that are required for the activation of NADPH oxidase.

scholarly journals Neuroprotective Benefits of Exercise and MitoQ on Memory Function, Mitochondrial Dynamics, Oxidative Stress, and Neuroinflammation in D-Galactose-Induced Aging Rats

2021 ◽  
Vol 11 (2) ◽  
pp. 164
Author(s):  
Jae-Hoon Jeong ◽  
Jung-Hoon Koo ◽  
Jang Soo Yook ◽  
Joon-Yong Cho ◽  
Eun-Bum Kang
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activity ◽  
Cognitive Impairment ◽  
Nadph Oxidase ◽  
Learning And Memory ◽  
Oxidase Activity ◽  
Mitochondrial Dynamics ◽  
Nadph Oxidase Activity ◽  
Aging Rats ◽  
Positive Effects

Exercise and antioxidants have health benefits that improve cognitive impairment and may act synergistically. In this study, we examined the effects of treadmill exercise (TE) and mitochondria-targeted antioxidant mitoquinone (MitoQ), individually or combined, on learning and memory, mitochondrial dynamics, NADPH oxidase activity, and neuroinflammation and antioxidant activity in the hippocampus of D-galactose-induced aging rats. TE alone and TE combined with MitoQ in aging rats reduced mitochondrial fission factors (Drp1, Fis1) and increased mitochondrial fusion factors (Mfn1, Mfn2, Opa1). These groups also exhibited improved NADPH oxidase activity and antioxidant activity (SOD-2, catalase). TE or MitoQ alone decreased neuroinflammatory response (COX-2, TNF-α), but the suppression was greater with their combination. In addition, aging-increased neuroinflammation in the dentate gyrus was decreased in TE but not MitoQ treatment. Learning and memory tests showed that, contrarily, MitoQ alone demonstrated some similar effects to TE but not a definitive improvement. In conclusion, this study demonstrated that MitoQ exerted some positive effects on aging when used as an isolated treatment, but TE had a more effective role on cognitive impairment, oxidative stress, inflammation, and mitochondria dysfunction. Our findings suggest that the combination of TE and MitoQ exerted no synergistic effects and indicated regular exercise should be the first priority in neuroprotection of age-related cognitive decline.

scholarly journals Regulation of NADPH Oxidase Activity in Phagocytes

2010 ◽  
Vol 285 (43) ◽  
pp. 33197-33208 ◽  
Author(s):  
Franck Debeurme ◽  
Antoine Picciocchi ◽  
Marie-Claire Dagher ◽  
Didier Grunwald ◽  
Sylvain Beaumel ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Nadph Oxidase Activity

MODULATION OF NADPH OXIDASE ACTIVITY

2011 ◽  
Vol 29 ◽  
pp. e315
Author(s):  
A. Schulz ◽  
V. Jankowski ◽  
W. Zidek ◽  
J. Jankowski
Keyword(s):  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Nadph Oxidase Activity

scholarly journals Attenuation of renal excretory responses to ANG II during inhibition of superoxide dismutase in anesthetized rats

2010 ◽  
Vol 298 (2) ◽  
pp. F401-F407 ◽  
Author(s):  
Md. Abdul Hye Khan ◽  
Mohammed Toriqul Islam ◽  
Alexander Castillo ◽  
Dewan Syed Abdul Majid
Keyword(s):  
Superoxide Dismutase ◽  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Ang Ii ◽  
Sod Activity ◽  
Doppler Flowmetry ◽  
Nadph Oxidase Activity ◽  
Blood Flows ◽  
Renal Responses

To examine the functional interaction between superoxide dismutase (SOD) and NADPH oxidase activity, we assessed renal responses to acute intra-arterial infusion of ANG II (0.5 ng·kg−1·min−1) before and during administration of a SOD inhibitor, diethyldithiocarbamate (DETC, 0.5 mg·kg−1·min−1), in enalaprilat-pretreated (33 μg·kg−1·min−1) rats ( n = 11). Total (RBF) and regional (cortical, CBF; medullary; MBF) renal blood flows were determined by Transonic and laser-Doppler flowmetry, respectively. Renal cortical and medullary tissue NADPH oxidase activity in vitro was determined using the lucigenin-chemiluminescence method. DETC treatment alone resulted in decreases in RBF, CBF, MBF, glomerular filtration rate (GFR), urine flow (V), and sodium excretion (UNaV) as reported previously. Before DETC, ANG II infusion decreased RBF (−18 ± 3%), CBF (−16 ± 3%), MBF [−5 ± 6%; P = not significant (NS)], GFR (−31 ± 4%), V (−34 ± 2%), and UNaV (−53 ± 3%). During DETC infusion, ANG II also caused similar reductions in RBF (−20 ± 4%), CBF (−19 ± 3%), MBF (−2 ± 2; P = NS), and in GFR (−22 ± 7%), whereas renal excretory responses (V; −12 ± 2%; UNaV; −24 ± 4%) were significantly attenuated compared with those before DETC. In in vitro experiments, ANG II (100 μM) enhanced NADPH oxidase activity both in cortical [13,194 ± 1,651 vs. 20,914 ± 2,769 relative light units (RLU)/mg protein] and in medullary (21,296 ± 2,244 vs. 30,597 ± 4,250 RLU/mg protein) tissue. Application of DETC (1 mM) reduced the basal levels and prevented ANG II-induced increases in NADPH oxidase activity in both tissues. These results demonstrate that renal excretory responses to acute ANG II administration are attenuated during SOD inhibition, which seems related to a downregulation of NADPH oxidase in the deficient condition of SOD activity.

NADPH-oxidase activity is elevated in penumbral and non-ischemic cerebral arteries following stroke

2006 ◽  
Vol 1111 (1) ◽  
pp. 111-116 ◽  
Author(s):  
Alyson A. Miller ◽  
Gregory J. Dusting ◽  
Carli L. Roulston ◽  
Christopher G. Sobey
Keyword(s):  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Cerebral Arteries ◽  
Nadph Oxidase Activity
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