scholarly journals In vitro knockout of human p47phox blocks superoxide anion production and LDL oxidation by activated human monocytes

2000 ◽  
Vol 41 (3) ◽  
pp. 489-495
Author(s):  
Erik A. Bey ◽  
Martha K. Cathcart
Keyword(s):  
Superoxide Anion ◽  
Ldl Oxidation ◽  
Human Monocytes ◽  
Superoxide Anion Production ◽  
Anion Production

Exposure of surfactant protein A to ozone in vitro and in vivo impairs its interactions with alveolar cells

1992 ◽  
Vol 262 (1) ◽  
pp. L63-L68 ◽  
Author(s):  
R. S. Oosting ◽  
J. F. Van Iwaarden ◽  
L. Van Bree ◽  
J. Verhoef ◽  
L. M. Van Golde ◽  
...  
Keyword(s):  
Superoxide Anion ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Alveolar Type ◽  
Type Ii ◽  
Superoxide Anion Production ◽  
Anion Production

This study focused on the question of whether exposure of surfactant protein A (SP-A) to ozone affected properties of this protein that may be involved in regulating alveolar type II cell and alveolar macrophage functions. In vitro exposure of human or canine SP-A to ozone reduced the ability of this protein to inhibit phorbol-ester induced secretion of [3H]phosphatidylcholine by alveolar type II cells in culture. Ozone-exposed human SP-A showed a decreased ability to enhance phagocytosis of herpes simplex virus and to stimulate superoxide anion production by alveolar macrophages. Experiments with elastase showed that ozone-exposed canine SP-A was more susceptible to proteolysis. A conformational change of the protein could underlie this phenomenon. Surfactant isolated from ozone-exposed rats (0.4 ppm ozone for 12 h) was also less able to stimulate superoxide anion production by alveolar macrophages than surfactant from control rats, which suggested that SP-A in vivo was also susceptible to ozone. The results of this study suggest that SP-A-alveolar cell interactions can be inhibited by ozone exposure, which may contribute to the toxicity of ozone in the lungs.

scholarly journals Mitochondria Superoxide Anion Production Contributes to Geranylgeraniol-Induced Death inLeishmania amazonensis

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Milene Valéria Lopes ◽  
Vânia Cristina Desoti ◽  
Angelo de Oliveira Caleare ◽  
Tânia Ueda-Nakamura ◽  
Sueli Oliveira Silva ◽  
...  
Keyword(s):  
Superoxide Anion ◽  
Chromatin Condensation ◽  
Ultrastructural Changes ◽  
Resonance Imaging ◽  
Superoxide Anion Production ◽  
Human Blood Cells ◽  
Anion Production ◽  
Bioactive Constituent ◽  
Intracellular Amastigote

Here we demonstrate the activity of geranylgeraniol, the major bioactive constituent from seeds ofBixa orellana, againstLeishmania amazonensis. Geranylgeraniol was identified through1H and13C nuclear magnetic resonance imaging and DEPT. The compound inhibited the promastigote and intracellular amastigote forms, with IC50of11±1.0and17.5±0.7 μg/mL, respectively. This compound was also more toxic to parasites than to macrophages and did not cause lysis in human blood cells. Morphological and ultrastructural changes induced by geranylgeraniol were observed in the protozoan by electronic microscopy and included mainly mitochondria alterations and an abnormal chromatin condensation in the nucleus. These alterations were confirmed by Rh 123 and TUNEL assays. Additionally, geranylgeraniol induces an increase in superoxide anion production. Collectively, ourin vitrostudies indicate geranylgeraniol as a selective antileishmanial that appears to be mediated by apoptosis-like cell death.

scholarly journals In vitro characterisation of fresh and frozen sex-sorted bull spermatozoa

2017 ◽  
Vol 29 (7) ◽  
pp. 1415 ◽  
Author(s):  
Shauna A. Holden ◽  
Craig Murphy ◽  
Juan F. Moreno ◽  
Stephen T. Butler ◽  
Andrew R. Cromie ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Superoxide Anion ◽  
Superoxide Anion Production ◽  
Holstein Friesian ◽  
Anion Production ◽  
And Oxidative Stress

This study sought to compare the in vitro characteristics of fresh and frozen non-sorted (NS) and sex-sorted (SS) bull spermatozoa. Experiment 1: Holstein–Friesian ejaculates (n = 10 bulls) were split across four treatments and processed: (1) NS fresh at 3 × 106 spermatozoa, (2) X-SS frozen at 2 × 106 spermatozoa, (3) X-SS fresh at 2 × 106 spermatozoa and (4) X-SS fresh at 1 × 106 spermatozoa. NS frozen controls of 20 × 106 spermatozoa per straw were sourced from previously frozen ejaculates (n = 3 bulls). Experiment 2: Aberdeen Angus ejaculates (n = 4 bulls) were split across four treatments and processed as: (1) NS fresh 3 × 106 spermatozoa, (2) Y-SS fresh at 1 × 106 spermatozoa, (3) Y-SS fresh at 2 × 106 spermatozoa and (4) X-SS fresh at 2 × 106 spermatozoa. Controls were sourced as per Experiment 1. In vitro assessments for progressive linear motility, acrosomal status and oxidative stress were carried out on Days 1, 2 and 3 after sorting (Day 0 = day of sorting. In both experiments SS fresh treatments had higher levels of agglutination in comparison to the NS fresh (P < 0.001), NS frozen treatments had the greatest PLM (P < 0.05) and NS spermatozoa exhibited higher levels of superoxide anion production compared with SS spermatozoa (P < 0.05). Experiment 1 found both fresh and frozen SS treatments had higher levels of viable acrosome-intact spermatozoa compared with the NS frozen treatments (P < 0.01).

scholarly journals First Evidence of In Vitro Effects of C6O4—A Substitute of PFOA—On Haemocytes of the Clam Ruditapes philippinarum

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 191
Author(s):  
Jacopo Fabrello ◽  
Francesca Targhetta ◽  
Maria Ciscato ◽  
Davide Asnicar ◽  
Ilaria Bernardini ◽  
...  
Keyword(s):  
Chromosomal Aberrations ◽  
Superoxide Anion ◽  
Ruditapes Philippinarum ◽  
Membrane Stability ◽  
Lysosomal Membrane ◽  
Superoxide Anion Production ◽  
Anion Production ◽  
Lysosomal Membrane Stability ◽  
In Vitro Effects

Alternative chemicals to per- and poly-fluoroalkyl substances have recently been introduced in various industrial processes. C6O4 (difluoro{[2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetic acid) is a new surfactant and emulsifier used as a replacement for perfluorooctanoic acid (PFOA). From an ecotoxicological point of view, in vitro assays are useful tools for assessing the negative effects and understanding the mechanisms of action of chemicals at the cellular level. Here, we present the results of an in vitro study in which the effects of C6O4 were evaluated—for the first time—on haemocytes of the clam Ruditapes philippinarum. Cells were exposed to three concentrations of C6O4 (0.05, 0.5, 5 μg/mL) and the effects on haemocyte viability, haemocyte morphology, differential haemocyte count, lysosomal membrane stability, superoxide anion production, acid phosphatase, and β-glucuronidase activities, as well as on the percentage of micronuclei and chromosomal aberrations were evaluated. The results demonstrated that C6O4 significantly affected haemocyte morphology, lysosomal membrane stability, hydrolytic enzyme activity, and superoxide anion production, and promoted chromosomal aberrations. To the best of our knowledge, this is the first study revealing the in vitro effects of C6O4, a substitute for PFOA, on haemocytes from a bivalve species.

Modulation of human neutrophil function in vitro by gastrin

1997 ◽  
Vol 153 (3) ◽  
pp. 475-483 ◽  
Author(s):  
M De la Fuente ◽  
M Carrasco ◽  
A Hernanz
Keyword(s):  
Superoxide Anion ◽  
Latex Bead ◽  
Human Neutrophils ◽  
Intracellular Camp ◽  
Maximal Effect ◽  
Superoxide Anion Production ◽  
Phagocytic Process ◽  
Anion Production ◽  
Camp Levels

Abstract We have studied the effects in vitro of gastrin-17 and gastrin-34, at concentrations from 10−14 m to 10−6 m, on several of the functions of peripheral blood human neutrophils, i.e. adherence to substrate, mobility (spontaneous and directed by a chemical gradient or chemotaxis), ingestion of inert particles (latex beads) and cells (Candida albicans) and superoxide anion production. Both gastrins inhibited several steps of the phagocytic process of human neutrophils, such as mobility and ingestion. By contrast, these peptides increased adherence and had no effect on superoxide anion production. In general, these effects were significant at peptide concentrations between 10−12 m and 10−8 m with a maximal effect at 10−10 m. In addition, gastrin peptides induced a significant increase in intracellular cAMP levels at 30, 60 and 120 s. Moreover, the inhibitory effect of gastrin-17 on the ingestion capacity of neutrophils (latex bead phagocytosis) was similar to that obtained with EGTA, a well-known extracellular calcium chelating compound. Gastrin-17 was found to inhibit completely the stimulation of latex bead phagocytosis in neutrophils caused by the calcium ionophore A23187. These results suggest that gastrin is a negative modulator of the phagocytic process of human neutrophils, and that this effect might involve an increase in intracellular cAMP levels and a decrease in calcium entry into the cells. Journal of Endocrinology (1997) 153, 475–483

Local Anesthetic Effects on Priming and Activation of Human Neutrophils

2001 ◽  
Vol 95 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Markus W. Hollmann ◽  
Ariane Gross ◽  
Niko Jelacin ◽  
Marcel E. Durieux
Keyword(s):  
Signaling Pathway ◽  
Local Anesthetics ◽  
Superoxide Anion ◽  
Platelet Activating Factor ◽  
Target Site ◽  
Polymorphonuclear Neutrophil ◽  
Superoxide Anion Production ◽  
Anion Production ◽  
Site Of Action

Background Local anesthetics (LAs) have been shown to inhibit human polymorphonuclear neutrophil (hPMN) functions in vitro, but mechanisms are poorly understood. In this study the authors determined how LAs affect superoxide anion production of hPMNs primed with platelet-activating factor (PAF). The authors studied which pharmacologic properties of LAs are important for this action and assessed the LA site of action within the PAF signaling pathway. Methods Metabolic activity of primed and/or activated hPMNs were measured using the cytochrome-c assay. hPMNs were incubated with several LAs for 1 h to assess interference with PAF signaling. Using protein kinase C (PKC) inhibitors, the PKC activator phorbol myristate acetate (PMA), and the phospholipase C (PLC) antagonist U-73122, we studied involvement of PKC and PLC in the priming process. Pertussis toxin (PTX) was used to characterize the G proteins mediating this pathway. Combined administration of lidocaine with PMA or PTX was used to determine the LA site of action within the priming pathway. Results Platelet-activating factor effectively primed hPMNs. Ester LAs (tetracaine and benzocaine) exerted the most profound inhibitory effect on PAF-primed hPMNs, whereas inhibitory potency of amide LAs increased with decreased charged fraction. The major PAF-induced priming pathway is PLC- and PKC-dependent and mainly Gq-mediated. The main target site for LA in this pathway is located upstream of PKC. Conclusions Local anesthetics in clinically relevant concentrations inhibit superoxide anion production of PAF-primed hPMNs. Effects on priming by these compounds might explain, at least in part, the previously unexplained difference between concentrations of LAs required for their antiinflammatory action in vitro and in vivo. This study suggests a target site for LAs within a Gq-coupled signaling pathway.

scholarly journals Inhibition by soya isoflavones of human polymorphonuclear leukocyte function: possible relevance for the beneficial effects of soya intake

2008 ◽  
Vol 99 (2) ◽  
pp. 240-247 ◽  
Author(s):  
Serenella Rotondo ◽  
Katarzyna Krauze-Brzósko ◽  
Stefano Manarini ◽  
Nicola Martelli ◽  
Romina Pecce ◽  
...  
Keyword(s):  
Superoxide Anion ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Superoxide Anion Production ◽  
Human Polymorphonuclear Leukocyte ◽  
Beneficial Effects ◽  
Asian Populations ◽  
Anion Production ◽  
Cytochrome C Reduction

Lower CVD incidence is reported in Asian populations consuming soya-containing food. As polymorphonuclear leukocytes (PMN) are involved in the risk of CVD, we investigated the modulatory effect of soya isoflavones on several PMN functions and their molecular mechanismsin vitro. PMN, isolated from blood from healthy subjects, were tested upon activation with 1 μm- n-formyl-methyl-leucyl-phenylalanine (fMLP) for superoxide anion production (ferric cytochrome c reduction) and released elastase (chromogenic test). PMN homotypic aggregates stimulated by fMLP or P-selectin in dynamic conditions were detected by optical microscopy. PMN, mixed with thrombin-activated, washed platelets, formed cell aggregates, measured by flow cytometry. Phosphorylation of Pyk2, a focal adhesion kinase, was studied by immunoprecipitation and immunoblotting with specific antibodies. Genistein, daidzein and equol inhibited superoxide anion production (IC500·25 (sem0·1), 21·0 (sem4·2) and 13·0 (sem2·8) μm, respectively); the release of elastase was prevented by genistein (IC5063 (sem17) μm). PMN homotypic aggregates, stimulated by fMLP, were significantly reduced (24 (sem12) and 51 (sem14) % of control) by 100 μmgenistein and equol. P-selectin-induced aggregates were reduced to 19 (sem6), 44 (sem10) and 28 (sem9) % of control by 100 μmgenistein, daidzein and equol, respectively. Genistein, daidzein and equol also significantly reduced mixed platelet-PMN aggregates (IC504·0 (sem0·9), 57 (sem6) and 66 (sem23) μm, respectively). In PMN challenged by fMLP or P-selectin, activation of Pyk2 was prevented by isoflavones. The cardioprotective effect of soya-containing food might be linked to reduction of PMN activation and PMN-platelet interaction, novel targets for the biological effects of soya isoflavones.

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