scholarly journals In vitro and in vivo modulation of NADPH-oxidase activity and reactive oxygen species production in human neutrophils by alpha-1 antitrypsin

2021 ◽  
pp. 00234-2021
Author(s):  
Padraig Hawkins ◽  
Thomas McEnery ◽  
Claudie Gabillard-Lefort ◽  
David A Bergin ◽  
Bader Alfawaz ◽  
...  

Oxidative stress from innate immune cells is a driving mechanism that underlies COPD pathogenesis. Individuals with alpha-1 antitrypsin (AAT) deficiency (AATD) have a dramatically increased risk of developing COPD. To understand this further, the aim of this study was to investigate whether AATD presents with altered neutrophil NADPH-oxidase activation, due to the specific lack of plasma AAT. Experiments were performed using circulating neutrophils isolated from healthy controls and individuals with AATD. Superoxide anion (O2−) production was determined from the rate of reduction of cytochrome c. Quantification of membrane NADPH-oxidase subunits was performed by mass spectrometry and western blot analysis. The clinical significance of our in vitro findings were assessed in patients with AATD and severe COPD receiving intravenous AAT replacement therapy. In vitro, AAT significantly inhibited O2− production by stimulated neutrophils and suppressed receptor stimulation of cyclic adenosimonophosphate (cAMP) and extracellular-signal regulated kinase (ERK)1/2 phosphorylation. In addition, AAT reduced plasma membrane translocation of cytosolic phox components of the NADPH-oxidase. Ex vivo, AATD neutrophils demonstrated increased plasma membrane associated p67phox and p47phox and significantly increased O2− production. The described variance in phox protein membrane assembly was resolved post AAT augmentation therapy in vivo, the effects of which significantly reduced AATD neutrophil O2− production to that of healthy control cells. These results expand our knowledge on the mechanism of neutrophil driven airways disease associated with AATD. Therapeutic AAT augmentation modified neutrophil NADPH-oxidase assembly and ROS production, with implications for clinical use in conditions in which oxidative stress plays a pathogenic role.

2021 ◽  
Vol 22 (12) ◽  
pp. 6196
Author(s):  
Anna Pieniazek ◽  
Joanna Bernasinska-Slomczewska ◽  
Lukasz Gwozdzinski

The presence of toxins is believed to be a major factor in the development of uremia in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Uremic toxins have been divided into 3 groups: small substances dissolved in water, medium molecules: peptides and low molecular weight proteins, and protein-bound toxins. One of the earliest known toxins is urea, the concentration of which was considered negligible in CKD patients. However, subsequent studies have shown that it can lead to increased production of reactive oxygen species (ROS), and induce insulin resistance in vitro and in vivo, as well as cause carbamylation of proteins, peptides, and amino acids. Other uremic toxins and their participation in the damage caused by oxidative stress to biological material are also presented. Macromolecules and molecules modified as a result of carbamylation, oxidative stress, and their adducts with uremic toxins, may lead to cardiovascular diseases, and increased risk of mortality in patients with CKD.


2009 ◽  
Vol 160 (5) ◽  
pp. 785-790 ◽  
Author(s):  
Eirini Maratou ◽  
Dimitrios J Hadjidakis ◽  
Anastasios Kollias ◽  
Katerina Tsegka ◽  
Melpomeni Peppa ◽  
...  

ObjectiveAlthough clinical hypothyroidism (HO) is associated with insulin resistance, there is no information on insulin action in subclinical hypothyroidism (SHO).Design and methodsTo investigate this, we assessed the sensitivity of glucose metabolism to insulin both in vivo (by an oral glucose tolerance test) and in vitro (by measuring insulin-stimulated rates of glucose transport in isolated monocytes with flow cytometry) in 21 euthyroid subjects (EU), 12 patients with HO, and 13 patients with SHO.ResultsAll three groups had comparable plasma glucose levels, with the HO and SHO having higher plasma insulin than the EU (P<0.05). Homeostasis model assessment index was increased in HO (1.97±0.22) and SHO (1.99±0.13) versus EU (1.27±0.16, P<0.05), while Matsuda index was decreased in HO (3.89±0.36) and SHO (4.26±0.48) versus EU (7.76±0.87, P<0.001), suggesting insulin resistance in both fasting and post-glucose state. At 100 μU/ml insulin: i) GLUT4 levels on the monocyte plasma membrane were decreased in both HO (215±19 mean fluorescence intensity, MFI) and SHO (218±24 MFI) versus EU (270±25 MFI, P=0.03 and 0.04 respectively), and ii) glucose transport rates in monocytes from HO (481±30 MFI) and SHO (462±19 MFI) were decreased versus EU (571±15 MFI, P=0.04 and 0.004 respectively).ConclusionsIn patients with HO and SHO: i) insulin resistance was comparable; ii) insulin-stimulated rates of glucose transport in isolated monocytes were decreased due to impaired translocation of GLUT4 glucose transporters on the plasma membrane; iii) these findings could justify the increased risk for insulin resistance-associated disorders, such as cardiovascular disease, observed in patients with HO or SHO.


2019 ◽  
Vol 133 (1) ◽  
pp. 117-134 ◽  
Author(s):  
Pamela L. Martín ◽  
Paula Ceccatto ◽  
María V. Razori ◽  
Daniel E.A. Francés ◽  
Sandra M.M. Arriaga ◽  
...  

Abstract We previously demonstrated in in vitro and ex vivo models that physiological concentrations of unconjugated bilirubin (BR) prevent oxidative stress (OS)-induced hepatocanalicular dysfunction and cholestasis. Here, we aimed to ascertain, in the whole rat, whether a similar cholestatic OS injury can be counteracted by heme oxygenase-1 (HO-1) induction that consequently elevates endogenous BR levels. This was achieved through the administration of hemin, an inducer of HO-1, the rate-limiting step in BR generation. We found that BR peaked between 6 and 8 h after hemin administration. During this time period, HO-1 induction fully prevented the pro-oxidant tert-butylhydroperoxide (tBuOOH)-induced drop in bile flow, and in the biliary excretion of bile salts and glutathione, the two main driving forces of bile flow; this was associated with preservation of the membrane localization of their respective canalicular transporters, bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2), which are otherwise endocytosed by OS. HO-1 induction counteracted the oxidation of intracellular proteins and membrane lipids induced by tBuOOH, and fully prevented the increase in the oxidized-to-total glutathione (GSHt) ratio, a sensitive parameter of hepatocellular OS. Compensatory elevations of the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) were also prevented. We conclude that in vivo HO-1 induction protects the liver from acute oxidative injury, thus preventing consequent cholestasis. This reveals an important role for the induction of HO-1 and the consequently elevated levels of BR in preserving biliary secretory function under OS conditions, thus representing a novel therapeutic tool to limit the cholestatic injury that bears an oxidative background.


2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Wei Zhu ◽  
Zhijian Zhao ◽  
Fu-Ju Chou ◽  
Li Zuo ◽  
Tongzu Liu ◽  
...  

Females develop kidney stones less frequently than males do. However, it is unclear if this gender difference is related to altered estrogen/estrogen receptor (ER) signaling. Here, we found that ER beta (ERβ) signals could suppress hepatic oxalate biosynthesis via transcriptional upregulation of the glyoxylate aminotransferase (AGT1) expression. Results from multiple in vitro renal cell lines also found that ERβ could function via suppressing the oxalate-induced injury through increasing the reactive oxygen species (ROS) production that led to a decrease of the renal calcium oxalate (CaOx) crystal deposition. Mechanism study results showed that ERβ suppressed oxalate-induced oxidative stress via transcriptional suppression of the NADPH oxidase subunit 2 (NOX2) through direct binding to the estrogen response elements (EREs) on the NOX2 5′ promoter. We further applied two in vivo mouse models with glyoxylate-induced renal CaOx crystal deposition and one rat model with 5% hydroxyl-L-proline-induced renal CaOx crystal deposition. Our data demonstrated that mice lacking ERβ (ERβKO) as well as mice or rats treated with ERβ antagonist PHTPP had increased renal CaOx crystal deposition with increased urinary oxalate excretion and renal ROS production. Importantly, targeting ERβ-regulated NOX2 with the NADPH oxidase inhibitor, apocynin, can suppress the renal CaOx crystal deposition in the in vivo mouse model. Together, results from multiple in vitro cell lines and in vivo mouse/rat models all demonstrate that ERβ may protect against renal CaOx crystal deposition via inhibiting the hepatic oxalate biosynthesis and oxidative stress-induced renal injury.


2011 ◽  
Vol 111 (5) ◽  
pp. 1242-1248 ◽  
Author(s):  
Damien Vitiello ◽  
Julien Boissière ◽  
Grégory Doucende ◽  
Sandrine Gayrard ◽  
Anne Polge ◽  
...  

Prolonged strenuous exercise (PSE) induces transient left ventricular (LV) dysfunction. Previous studies suggest that β-adrenergic pathway desensitization could be involved in this phenomenon, but it remains to be confirmed. Moreover, other underlying mechanisms involving oxidative stress have been recently proposed. The present study aimed to evaluate the involvement of both the β-adrenergic pathway and NADPH oxidase (Nox) enzyme-induced oxidative stress in myocardial dysfunction in rats following PSE. Rats were divided into 4 groups: controls (Ctrl), 4-h exercised on treadmill (PSE), and 2 groups in which Nox enzyme was inhibited with apocynin treatment (Ctrl APO and PSE APO, respectively). We evaluated cardiac function in vivo and ex vivo during basal conditions and isoproterenol stress. GSH/GSSG ratio, cardiac troponin I (cTnI) release, and lipid peroxidation (MDA) were evaluated. PSE induced a decrease in LV developed pressure, intrinsic myocardial contractility, and relaxation associated with an increase in plasma cTnI release. Our in vivo and ex vivo results demonstrated no differences in myocardial response to isoproterenol and of effective dose 50 between control and PSE rats. Interestingly, the LV dysfunction was reversed by apocynin treatment. Moreover, apocynin prevented cellular oxidation [GSH/GSSG ratio: PSE APO rats vs. PSE rats in arbitrary units (au): 1.98 ± 0.07 vs. 1.35 ± 0.10; P < 0.001]. However, no differences in MDA were observed between groups. These data suggest that myocardial dysfunction observed after PSE was not due to β-adrenergic receptor desensitization but could be due to a signaling oxidative stress from the Nox enzyme.


2021 ◽  
Vol 22 (22) ◽  
pp. 12277
Author(s):  
En-Shao Liu ◽  
Nai-Ching Chen ◽  
Tzu-Ming Jao ◽  
Chien-Liang Chen

Medial vascular calcification has emerged as a key factor contributing to cardiovascular mortality in patients with chronic kidney disease (CKD). Vascular smooth muscle cells (VSMCs) with osteogenic transdifferentiation play a role in vascular calcification. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitors reduce reactive oxygen species (ROS) production and calcified-medium–induced calcification of VSMCs. This study investigates the effects of dextromethorphan (DXM), an NADPH oxidase inhibitor, on vascular calcification. We used in vitro and in vivo studies to evaluate the effect of DXM on artery changes in the presence of hyperphosphatemia. The anti-vascular calcification effect of DXM was tested in adenine-fed Wistar rats. High-phosphate medium induced ROS production and calcification of VSMCs. DXM significantly attenuated the increase in ROS production, the decrease in ATP, and mitochondria membrane potential during the calcified-medium–induced VSMC calcification process (p < 0.05). The protective effect of DXM in calcified-medium–induced VSMC calcification was not further increased by NADPH oxidase inhibitors, indicating that NADPH oxidase mediates the effect of DXM. Furthermore, DXM decreased aortic calcification in Wistar rats with CKD. Our results suggest that treatment with DXM can attenuate vascular oxidative stress and ameliorate vascular calcification.


2020 ◽  
Vol 16 (3) ◽  
pp. 284-293
Author(s):  
George Laylson da Silva Oliveira ◽  
Maria das Dores Alves de Oliveira ◽  
Maria da Conceição Oliveira Prado ◽  
Alexandre de Barros Falcão Ferraz ◽  
José Carlos Correia Lima da Silva ◽  
...  

Background: Garcinielliptone FC corresponds to a polyprenylated acylphloroglucinol having a benzophenonic core (diphenylmethanone) substituted with isoprenyl(s) group(s) (3-methyl-2-butenyl) and 2-isopropenyl-hex-5-enyl. Objective: The present work evaluated the antioxidant activity of garcinielliptone FC (GFC) in vitro against non-biological radicals [2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2'-azinobis-3- ethylbenzothiazoline-6-sulfonic acid (ABTS•+)] and ex vivo against oxidative damage induced by AAPH (2,2'-azobis-2-methylpropionamidine dihydrochloride) and iron/citrate ion in erythrocytes and mitochondria, respectively. Methods: In addition to the protective effect, the main biochemical indexes of oxidative stress, such as lipid peroxidation through the formation of Thiobarbituric Acid Reactive Substances (TBARS), Superoxide Dismutase (SOD), Catalase (CAT) activity and reduced glutathione (GSH) levels. Results: According to the results obtained in erythrocytes, the antioxidant results at concentrations of 0.1, 0.3, 0.7, 1.5 and 3.0 mM were 26.34 ± 0.68, 43.39 ± 2.17, 62.27 ± 2.17, 86.69 ± 0.47 and 92.89 ± 0.45%, respectively, where GFC reduced the rate of oxidative hemolysis when compared to AAPH (p<0.05). The antioxidant activity observed in erythrocytes was also seen in mitochondria in which GFC reduced mitochondrial swelling by increasing the absorbance when compared to iron/citrate ion complex (p<0.05). In both biological models, GFC had an antioxidant effect on erythrocyte and mitochondrial redox balance when analyzing oxidative stress biomarkers, such as reduction of lipid peroxidation and inhibition of depletion in the activity of SOD, CAT and GSH levels. Conclusion: In conclusion, GFC had in vitro and ex vivo antioxidant activity against oxidative damage induced in erythrocytes and mitochondria acting on the erythrocytic and mitochondrial redox balance.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Vamsi K Addanki ◽  
Pei-Suen Tsou ◽  
Ho-Leung Fung

We hypothesize that superoxide (SO) accumulation is not a critical causative factor in inducing nitroglycerin (NTG) tolerance. Using p47phox−/− and gp91−/− mice vs. their respective wild-type (WT) controls, we showed that aorta from mice null of these critical NADPH oxidase subunits exhibited similar vascular tolerance after NTG dosing (20 mg/kg sc, tid for 3 days), as indicated by their ex vivo pEC 50 and cyclic guanosine monophosphate (cGMP, pmol/mg protein) accumulation upon NTG challenge. In vitro aorta SO production (cpm/mg dry weight) was enhanced by NTG incubation both in p47phox null and WT mice (Table 1 ). Pre-exposure of isolated mice aorta to 100 microM NTG for 1 hr resulted in vascular tolerance toward NTG and increased SO accumulation. Oxypurinol (Oxy, 1mM) reduced SO but failed to attenuate vascular tolerance (Table 2 ). In LLC-PK1 cells, pre-exposure to NTG (1 microM for 4 hours) resulted in increased SO accumulation and reduced cGMP response to 3.16 microM NTG vs. vehicle control. Exposure to 1 microM angiotensin II increased SO but did not reduce cGMP response. Taken together, these results indicate that in vivo vascular NTG tolerance in mice does not require the presence of the p47phox and gp91phox subunits of NADPH oxidase, and that increased SO accumulation may be a consequence, rather than a cause, of NTG tolerance. Table 1 Table 2


PLoS ONE ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. e0173711 ◽  
Author(s):  
Ya-Ling Feng ◽  
Yong-Xiang Yin ◽  
Jian Ding ◽  
Hua Yuan ◽  
Lan Yang ◽  
...  

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