The Flavonols Quercetin, Myricetin, Kaempferol, and Galangin Inhibit the Net Oxygen Consumption by Immune Complex- Stimulated Human and Rabbit Neutrophils

2014 ◽  
Vol 69 (7-8) ◽  
pp. 346-356 ◽  
Author(s):  
Andréa S. G. Figueiredo-Rinhel ◽  
Everton O. L. Santos ◽  
Luciana M. Kabeya ◽  
Ana Elisa C. S. Azzolini ◽  
Livia M. C. Simões-Ambrosio ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Immune Complex ◽  
Respiratory Burst ◽  
Human Neutrophil ◽  
Inflammatory Diseases ◽  
Cell Types ◽  
Oxygen Electrode ◽  
Experimental Models ◽  
Human Neutrophils ◽  
Experimental Conditions

Stimulated human neutrophils exhibit increased net oxygen consumption (NOC) due to the conversion of O2 into the superoxide anion by the NADPH oxidase enzymatic complex during the respiratory burst. In several inflammatory diseases, overproduction of these oxidants causes tissue damage. The present study aims to: (a) optimize the experimental conditions used to measure the NOC in serum-opsonized zymosan (OZ)-and insoluble immune complex (i-IC)-stimulated human and rabbit neutrophils; and (b) compare the effect of four flavonols (quercetin, myricetin, kaempferol, and galangin) on this activity. We used a Clark-type oxygen electrode to measure the NOC of stimulated neutrophils. Eliciting the neutrophil respiratory burst with OZ and i-IC yielded similar maximum O2 uptake levels within the same species, but the human neutrophil NOC was almost four times higher than the rabbit neutrophil NOC. The optimal experimental conditions established for both cell types were 4·106 neutrophils mL-1, 2 mg mL-1 OZ, and 240 µg mL-1 i-IC. Upon stimulation with OZ or i-IC, the tested flavonols reduced the human and rabbit neutrophil NOC in the same order of potency - quercetin and galangin were the most and the least potent, respectively. These compounds were around four times more effective in inhibiting the rabbit as compared to the human neutrophil NOC, respectively. The four flavonols were not toxic to human or rabbit neutrophils. The experimental conditions used are suitable for both the determination of human and rabbit neutrophil NOC and for the assessment of the modulatory effects of natural compounds on these activities. The relationship between the level of NOC and the inhibitory potency of the flavonols suggests that rabbit neutrophils can be useful experimental models to predict the effect of drugs on immune complexstimulated human neutrophils.

Nuclear receptor Nur77: its role in chronic inflammatory diseases

2021 ◽  
Author(s):  
Sanne C. Lith ◽  
Carlie J.M. de Vries
Keyword(s):  
Nuclear Receptor ◽  
Inflammatory Disease ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Inflammatory Diseases ◽  
Cell Types ◽  
Experimental Models ◽  
Therapeutic Interventions ◽  
Alternative Mechanism ◽  
Signaling Complex

Abstract Nur77 is a nuclear receptor that has been implicated as a regulator of inflammatory disease. The expression of Nur77 increases upon stimulation of immune cells and is differentially expressed in chronically inflamed organs in human and experimental models. Furthermore, in a variety of animal models dedicated to study inflammatory diseases, changes in Nur77 expression alter disease outcome. The available studies comprise a wealth of information on the function of Nur77 in diverse cell types and tissues. Negative cross-talk of Nur77 with the NFκB signaling complex is an example of Nur77 effector function. An alternative mechanism of action has been established, involving Nur77-mediated modulation of metabolism in macrophages as well as in T cells. In this review, we summarize our current knowledge on the role of Nur77 in atherosclerosis, inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, and sepsis. Detailed insight in the control of inflammatory responses will be essential in order to advance Nur77-targeted therapeutic interventions in inflammatory disease.

scholarly journals Effects of oxygen tension and pH on the respiratory burst of human neutrophils

Blood ◽  
1979 ◽  
Vol 53 (6) ◽  
pp. 1133-1139 ◽  
Author(s):  
TG Gabig ◽  
SI Bearman ◽  
BM Babior
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Respiratory Burst ◽  
Low Ph ◽  
Human Neutrophils ◽  
Respiratory Burst Activity ◽  
Similar Dependence ◽  
Activated Neutrophils ◽  
Acidic Conditions ◽  
O2 Production

Abstract The respiratory burst of human neutrophils was measured under conditions of hypoxia and low pH. O2 -- production by neutrophils activated with opsonized zymosan fell slowly as the oxygen concentration declined to 1%, then dropped more sharply, reaching negligible levels at oxygen concentrations less than 0.25%. Production was half maximal at an oxygen concentration of 0.35% (equivalent to approximately 10-microM dissolved oxygen). O2- production by the cell- free O2- -forming system prepared from zymosan-activated neutrophils showed a similar dependence on oxygen concentration. A drop in pH caused decreases in both oxygen consumption and O2-- production by zymosan-treated neutrophils, values at PH 6.0 being 10%--20% of those observed at pH 7.5. Experiments with the cell-free O2-- -forming system suggested that this decline in respiratory burst activity at low pH was due to inefficient activation of the O2-- -forming enzyme under acidic conditions.

Chemokines in Oral Inflammatory Diseases: Apical Periodontitis and Periodontal Disease

2007 ◽  
Vol 86 (4) ◽  
pp. 306-319 ◽  
Author(s):  
T.A. Silva ◽  
G.P. Garlet ◽  
S.Y. Fukada ◽  
J.S. Silva ◽  
F.Q. Cunha
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Bone Cells ◽  
Inflammatory Diseases ◽  
Cell Types ◽  
Cellular Responses ◽  
Experimental Models ◽  
Periodontal Tissue ◽  
Oral Diseases ◽  
Specific Receptors

The inflammatory oral diseases are characterized by the persistent migration of polymorphonuclear leukocytes, monocytes, lymphocytes, plasma and mast cells, and osteoblasts and osteoclasts. In the last decade, there has been a great interest in the mediators responsible for the selective recruitment and activation of these cell types at inflammatory sites. Of these mediators, the chemokines have received particular attention in recent years. Chemokine messages are decoded by specific receptors that initiate signal transduction events, leading to a multitude of cellular responses, including chemotaxis and activation of inflammatory and bone cells. However, little is known about their role in the pathogenesis of inflammatory oral diseases. The purpose of this review is to summarize the findings regarding the role of chemokines in periapical and periodontal tissue inflammation, and the integration, into experimental models, of the information about the role of chemokines in human diseases.

scholarly journals Relation of human neutrophil phorbol ester receptor occupancy and NADPH- oxidase activity

Blood ◽  
1982 ◽  
Vol 60 (2) ◽  
pp. 333-339 ◽  
Author(s):  
AI Tauber ◽  
DB Brettler ◽  
EA Kennington ◽  
PM Blumberg
Keyword(s):  
Nadph Oxidase ◽  
Phorbol Ester ◽  
Respiratory Burst ◽  
Human Neutrophil ◽  
Oxidase Activity ◽  
Receptor Occupancy ◽  
Human Neutrophils ◽  
Binding Studies ◽  
Nadph Oxidase Activity ◽  
Phorbol Ester Receptor

Abstract Phorbol esters are potent stimulants of the respiratory burst of the human neutrophil as assessed by superoxide (O2-) generation in whole cells and by NADPH-oxidase activity in a broken-cell 27,000-g particulate fraction. Phorbol 12-myristate, 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDBu) stimulate production of O2- by human neutrophils with ED50 concentrations of 3.9 +/- 2.1 and 41.7 +/- 7.1 nM, respectively. The relation of biologic activity to receptor occupancy was assessed with binding studies of PMA and PDBu. Phorbol ester binding revealed a single high affinity phorbol ester receptor present at 7.6 x 10(5) sites/cell. The binding affinities for PMA and PDBu, 4.9 nM and 38.4 nM, respectively, agreed quantitatively with that of biologic potencies. Because of the high concentration of phorbol ester receptors (up to 125 nM) and the large amount of nonspecific binding at high cell density, apparent discrepancies between ED50′s for NADPH-oxidase and whole cell O2- generation were noted. With the use of low cell concentrations, quantitative agreement between intact cell production of O2-, NADPH-oxidase activity, and receptor binding was found. These results further support the identity of the NADPH-oxidase as the enzymatic source of respiratory burst O2- production in human neutrophils.

scholarly journals Relation of human neutrophil phorbol ester receptor occupancy and NADPH- oxidase activity

Blood ◽  
1982 ◽  
Vol 60 (2) ◽  
pp. 333-339
Author(s):  
AI Tauber ◽  
DB Brettler ◽  
EA Kennington ◽  
PM Blumberg
Keyword(s):  
Nadph Oxidase ◽  
Phorbol Ester ◽  
Respiratory Burst ◽  
Human Neutrophil ◽  
Oxidase Activity ◽  
Receptor Occupancy ◽  
Human Neutrophils ◽  
Binding Studies ◽  
Nadph Oxidase Activity ◽  
Phorbol Ester Receptor

Phorbol esters are potent stimulants of the respiratory burst of the human neutrophil as assessed by superoxide (O2-) generation in whole cells and by NADPH-oxidase activity in a broken-cell 27,000-g particulate fraction. Phorbol 12-myristate, 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDBu) stimulate production of O2- by human neutrophils with ED50 concentrations of 3.9 +/- 2.1 and 41.7 +/- 7.1 nM, respectively. The relation of biologic activity to receptor occupancy was assessed with binding studies of PMA and PDBu. Phorbol ester binding revealed a single high affinity phorbol ester receptor present at 7.6 x 10(5) sites/cell. The binding affinities for PMA and PDBu, 4.9 nM and 38.4 nM, respectively, agreed quantitatively with that of biologic potencies. Because of the high concentration of phorbol ester receptors (up to 125 nM) and the large amount of nonspecific binding at high cell density, apparent discrepancies between ED50′s for NADPH-oxidase and whole cell O2- generation were noted. With the use of low cell concentrations, quantitative agreement between intact cell production of O2-, NADPH-oxidase activity, and receptor binding was found. These results further support the identity of the NADPH-oxidase as the enzymatic source of respiratory burst O2- production in human neutrophils.

scholarly journals Effects of oxygen tension and pH on the respiratory burst of human neutrophils

Blood ◽  
1979 ◽  
Vol 53 (6) ◽  
pp. 1133-1139 ◽  
Author(s):  
TG Gabig ◽  
SI Bearman ◽  
BM Babior
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Respiratory Burst ◽  
Low Ph ◽  
Human Neutrophils ◽  
Respiratory Burst Activity ◽  
Similar Dependence ◽  
Activated Neutrophils ◽  
Acidic Conditions ◽  
O2 Production

The respiratory burst of human neutrophils was measured under conditions of hypoxia and low pH. O2 -- production by neutrophils activated with opsonized zymosan fell slowly as the oxygen concentration declined to 1%, then dropped more sharply, reaching negligible levels at oxygen concentrations less than 0.25%. Production was half maximal at an oxygen concentration of 0.35% (equivalent to approximately 10-microM dissolved oxygen). O2- production by the cell- free O2- -forming system prepared from zymosan-activated neutrophils showed a similar dependence on oxygen concentration. A drop in pH caused decreases in both oxygen consumption and O2-- production by zymosan-treated neutrophils, values at PH 6.0 being 10%--20% of those observed at pH 7.5. Experiments with the cell-free O2-- -forming system suggested that this decline in respiratory burst activity at low pH was due to inefficient activation of the O2-- -forming enzyme under acidic conditions.

Pathogenic angiogenesis in IBD and experimental colitis: new ideas and therapeutic avenues

2007 ◽  
Vol 293 (1) ◽  
pp. G5-G18 ◽  
Author(s):  
John H. Chidlow ◽  
Deepti Shukla ◽  
Matthew B. Grisham ◽  
Christopher G. Kevil
Keyword(s):  
Immune Cell ◽  
Inflammatory Diseases ◽  
Antiangiogenic Therapy ◽  
Experimental Colitis ◽  
Cell Types ◽  
Experimental Models ◽  
Similar Degree ◽  
Pathological Angiogenesis ◽  
Inhibition Of Angiogenesis ◽  
New Ideas

Angiogenesis is now understood to play a major role in the pathology of chronic inflammatory diseases and is indicated to exacerbate disease pathology. Recent evidence shows that angiogenesis is crucial during inflammatory bowel disease (IBD) and in experimental models of colitis. Examination of the relationship between angiogenesis and inflammation in experimental colitis shows that initiating factors for these responses simultaneously increase as disease progresses and correlate in magnitude. Recent studies show that inhibition of the inflammatory response attenuates angiogenesis to a similar degree and, importantly, that inhibition of angiogenesis does the same to inflammation. Recent data provide evidence that differential regulation of the angiogenic mediators involved in IBD-associated chronic inflammation is the root of this pathological angiogenesis. Many factors are involved in this phenomenon, including growth factors/cytokines, chemokines, adhesion molecules, integrins, matrix-associated molecules, and signaling targets. These factors are produced by various vascular, inflammatory, and immune cell types that are involved in IBD pathology. Moreover, recent studies provide evidence that antiangiogenic therapy is a novel and effective approach for IBD treatment. Here we review the role of pathological angiogenesis during IBD and experimental colitis and discuss the therapeutic avenues this recent knowledge has revealed.

Epithelial Organotypic Cultures: A Viable Model to Address Mechanisms of Carcinogenesis by Epitheliotropic Viruses

2018 ◽  
Vol 18 (4) ◽  
pp. 246-255 ◽  
Author(s):  
Lara Termini ◽  
Enrique Boccardo
Keyword(s):  
Three Dimensional ◽  
Cell Types ◽  
Experimental Models ◽  
Biological Research ◽  
Specific Gene ◽  
Specific Cell ◽  
Organotypic Cultures ◽  
Skin Physiology

In vitro culture of primary or established cell lines is one of the leading techniques in many areas of basic biological research. The use of pure or highly enriched cultures of specific cell types obtained from different tissues and genetics backgrounds has greatly contributed to our current understanding of normal and pathological cellular processes. Cells in culture are easily propagated generating an almost endless source of material for experimentation. Besides, they can be manipulated to achieve gene silencing, gene overexpression and genome editing turning possible the dissection of specific gene functions and signaling pathways. However, monolayer and suspension cultures of cells do not reproduce the cell type diversity, cell-cell contacts, cell-matrix interactions and differentiation pathways typical of the three-dimensional environment of tissues and organs from where they were originated. Therefore, different experimental animal models have been developed and applied to address these and other complex issues in vivo. However, these systems are costly and time consuming. Most importantly the use of animals in scientific research poses moral and ethical concerns facing a steadily increasing opposition from different sectors of the society. Therefore, there is an urgent need for the development of alternative in vitro experimental models that accurately reproduce the events observed in vivo to reduce the use of animals. Organotypic cultures combine the flexibility of traditional culture systems with the possibility of culturing different cell types in a 3D environment that reproduces both the structure and the physiology of the parental organ. Here we present a summarized description of the use of epithelial organotypic for the study of skin physiology, human papillomavirus biology and associated tumorigenesis.

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