Inhibition of the n-formylmethionyl-leucyl-phenylalanine induced respiratory burst in human neutrophils by adrenergic agonists and prostaglandins of the E series

1981 ◽  
Vol 59 (9) ◽  
pp. 915-920 ◽  
Author(s):  
Kenneth Wong ◽  
Karen Freund
Keyword(s):  
Adenylate Cyclase ◽  
Respiratory Burst ◽  
Human Neutrophils ◽  
Superoxide Anions ◽  
Adrenergic Agonists ◽  
Active Inhibition ◽  
Prostaglandin F ◽  
Membrane Bound ◽  
Prostaglandins E

Exogenous prostaglandins E1 and E2 and L-isoproterenol potently inhibited the production of superoxide anions by human neutrophils activated in vitro by n-formylmethionyl-leucyl-phenylalanine (FMLP). An estimated ID50 of 50 nM was found for all three agents while L-epinephrine and prostaglandin F2α were 10 and 100 fold, respectively, less active. Inhibition occurred whether these agents were added before, together with, or after the addition of the tripeptide to cell suspensions. Cells treated with dibutyryl adenosine 3′,5′-monophosphate also expressed reduced rates of superoxide synthesis thus suggesting that the hormonal inhibitors acted indirectly by stimulating membrane bound adenylate cyclase.

PRODUCTION OF THROMBOXANE B2 BY INTRA-UTERINE TISSUES FROM PREGNANT GOATS IN VITRO

1978 ◽  
Vol 78 (1) ◽  
pp. 159-160 ◽  
Author(s):  
M. D. MITCHELL ◽  
A. P. F. FLINT ◽  
E. J. KINGSTON ◽  
G. D. THORBURN ◽  
J. S. ROBINSON
Keyword(s):  
Thromboxane B2 ◽  
Basic Data ◽  
University Of Oxford ◽  
Obstetrics And Gynaecology ◽  
Nuffield Department ◽  
John Radcliffe Hospital ◽  
Prostaglandin F ◽  
Prostaglandins E

Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU (Received 9 February 1978) It has been shown that prostaglandins play an important role in the mechanism of parturition in many species, including the goat (Currie & Thorburn, 1977; Thorburn, Challis & Robinson, 1977). Recently we have demonstrated that intra-uterine tissues from pregnant goats, when superfused in vitro, produce prostaglandins E and F (PGE, PGF) and 13,14-dihydro-15-oxo-prostaglandin F at various rates (Mitchell, Flint, Robinson & Thorburn, 1978). The exciting discoveries of two potent prostaglandin-like compounds, thromboxane A2 (TXA2; Hamberg, Svensson & Samuelsson, 1975) and prostacyclin (PGI2; Moncada, Gryglewski, Bunting & Vane, 1976), have radically altered our thinking on prostaglandins and basic data are urgently required concerning these compounds. Since prostaglandin endoperoxides are the immediate precursors of both prostaglandins and TXA2 (and PGI2) and since TXA2 has been shown to cause contraction of a number

scholarly journals G Protein-Coupled Estrogen Receptor 1 Regulates Human Neutrophil Functions

2017 ◽  
Vol 2 (1) ◽  
pp. 1-13 ◽  
Author(s):  
M. Carmen Rodenas ◽  
Nicola Tamassia ◽  
Isabel Cabas ◽  
Federica Calzetti ◽  
José Meseguer ◽  
...  
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Protein Kinase ◽  
G Protein ◽  
Respiratory Burst ◽  
Human Neutrophils ◽  
G Protein Coupled ◽  
Estrogen Receptor 1

Background: The role of estrogens in immune functioning is relatively well known under both physiological and pathological conditions. Neutrophils are the most abundant circulating leukocytes in humans, and their abundance and function are regulated by estrogens, since they express estrogen receptors (ERs). Traditionally, estrogens were thought to act via classical nuclear ERs, namely ERα and ERβ. However, it was observed that some estrogens induced biological effects only minutes after their application. This rapid, “nongenomic” effect of estrogens is mediated by a membrane-anchored receptor called G protein-coupled estrogen receptor 1 (GPER1). Nevertheless, the expression and role of GPER1 in the immune system has not been exhaustively studied, and its relevance in neutrophil functions remains unknown. Methods: Human neutrophils were incubated in vitro with 10-100 µM of the GPER1-specific agonist G1 alone or in combination with lipopolysaccharide. GPER1 expression and subcellular localization, respiratory burst, life span, gene expression profile, and cell signaling pathways involved were then analyzed in stimulated neutrophils. Results: Human neutrophils express a functional GPER1 which regulates their functions through cAMP/protein kinase A/cAMP response element-binding protein, p38 mitogen-activated protein kinase, and extracellular regulated MAPK signaling pathways. Thus, GPER1 activation in vitro increases the respiratory burst of neutrophils, extends their life span, and drastically alters their gene expression profile. Conclusions: Our results demonstrate that GPER1 activation promotes the polarization of human neutrophils towards a proinflammatory phenotype and point to GPER1 as a potential therapeutic target in immune diseases where neutrophils play a key role.

Leukocyte antibacterial functions are not impaired by perfluorocarbon exposure in vitro

2008 ◽  
Vol 295 (1) ◽  
pp. L134-L142 ◽  
Author(s):  
Dirk Haufe ◽  
Eva Koenigshausen ◽  
Lilla Knels ◽  
Martina Wendel ◽  
Sebastian N. Stehr ◽  
...  
Keyword(s):  
Host Defense ◽  
In Vitro Model ◽  
Polymorphonuclear Neutrophils ◽  
Human Neutrophils ◽  
Intracellular Uptake ◽  
E Coli ◽  
Transmission Electron ◽  
Membrane Bound ◽  
Vitro Model

Application of liquid, aerosolized, and vaporized perfluorocarbons (PFC) in acute lung injury has shown anti-inflammatory effects. Although this may be beneficial in states of pulmonary hyperinflammation, it also could increase susceptibility to nosocomial lung infection. We hypothesized that PFC impair cellular host defense and therefore investigated in an in vitro model the influence of perfluorohexane (PFH) on crucial mechanisms of bacterial elimination in human neutrophils and monocytes. Using scanning and transmission electron microscopy, we could show membrane-bound and ingested PFH particles that morphologically did not alter adherence and phagocytosis of Escherichia coli or leukocyte viability. The amount of adherent and phagocytosed bacteria as determined by flow cytometry was not influenced in cells only pretreated with PFH for 1 and 4 h. When PFH was present during E. coli challenge, bacterial adherence was decreased in polymorphonuclear neutrophils, but respective intracellular uptake was not impaired and was even significantly promoted in monocytes. Overall, E. coli-induced respiratory burst capacity was not reduced by PFH. Our findings provide evidence that key functions of innate host defense are not compromised by PFH treatment in vitro.

scholarly journals Sulfate import in Salmonella Typhimurium impacts bacterial aggregation and the respiratory burst in human neutrophils

2021 ◽  
Author(s):  
T. L. Westerman ◽  
M. K. Sheats ◽  
J. R. Elfenbein
Keyword(s):  
Respiratory Burst ◽  
Gene Deletion ◽  
Single Gene ◽  
Protein A ◽  
Human Neutrophils ◽  
Deletion Mutants ◽  
Flagellar Motility ◽  
Neutrophil Respiratory Burst ◽  
Single Gene Deletion

During enteric salmonellosis, neutrophil generated reactive oxygen species alter the gut microenvironment favoring survival of Salmonella Typhimurium. While the type-3 secretion system-1 (T3SS-1) and flagellar motility are potent Salmonella Typhimurium agonists of the neutrophil respiratory burst in vitro, neither of these pathways alone are responsible for stimulation of a maximal respiratory burst. In order to identify Salmonella Typhimurium genes that impact the magnitude of the neutrophil respiratory burst, we performed a two-step screen of defined mutant libraries in co-culture with human neutrophils. We first screened Salmonella Typhimurium mutants lacking defined genomic regions and then tested single gene deletion mutants representing particular regions under selection. A subset of single gene deletion mutants were selected for further investigation. Mutants in four genes, STM1696 (sapF), STM2201 (yeiE), STM2112 (wcaD), and STM2441 (cysA), induced an attenuated respiratory burst. We linked the altered respiratory burst to reduced T3SS-1 expression and/or altered flagellar motility for two mutants (ΔSTM1696 and ΔSTM2201). The ΔSTM2441 mutant, defective for sulfate transport, formed aggregates in minimal media and adhered to surfaces in rich media, suggesting a role for sulfur homeostasis in regulation of aggregation/adherence. We linked the aggregation/adherence phenotype of the ΔSTM2441 mutant to biofilm-associated protein A and flagellins and hypothesize that aggregation caused the observed reduction in the magnitude of the neutrophil respiratory burst. Our data demonstrate that Salmonella Typhimurium has numerous mechanisms to limit the magnitude of the neutrophil respiratory burst. These data further inform our understanding of how Salmonella may alter human neutrophil antimicrobial defenses.

Control of adipose tissue lipolysis in ectotherm vertebrates

1992 ◽  
Vol 263 (4) ◽  
pp. R857-R862 ◽  
Author(s):  
R. H. Migliorini ◽  
J. S. Lima-Verde ◽  
C. R. Machado ◽  
G. M. Cardona ◽  
M. A. Garofalo ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Adenylate Cyclase ◽  
Lipolytic Activity ◽  
Adenylate Cyclase System ◽  
Triacylglycerol Lipase ◽  
Membrane Bound ◽  
Adipose Tissue Lipolysis ◽  
Toad Bufo

Lipolytic activity of fish (Hoplias malabaricus), toad (Bufo paracnemis), and snake (Philodryas patagoniensis) adipose tissue was investigated in vivo and in vitro. Catecholamines or glucagon did not affect the release of free fatty acids (FFA) by incubated fish and toad adipose tissue. Catecholamines also failed to activate snake adipose tissue lipolysis, which even decreased in the presence of epinephrine. However, glucagon stimulated both the lipolytic activity of reptilian tissue in vitro and the mobilization of FFA to plasma when administered to snakes in vivo. The release of FFA from incubated fish, amphibian, and reptilian adipose tissue increased markedly in the presence of cAMP or xanthine derivatives, inhibitors of phosphodiesterase. Forskolin or fluoride, activators of specific components of the adenylate cyclase system, strongly stimulated toad adipose tissue lipolysis. The data suggest that adipocyte triacylglycerol lipase of ectotherm vertebrates is activated by a cAMP-mediated phosphorylation and that the organization of the membrane-bound adenylate cyclase system is similar to that of mammals.

GM-CSF increases in vitro the respiratory burst of human neutrophils after liver transplantation

1999 ◽  
Vol 25 (6) ◽  
pp. 612-615 ◽  
Author(s):  
K. Jaeger ◽  
D. Scheinichen ◽  
J. Heine ◽  
H. Ruschulte ◽  
E. Kuse ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Respiratory Burst ◽  
Human Neutrophils ◽  
Gm Csf

Impairment of gonadotropin binding occurs during membrane rigidification in plasma membrane samples prepared from regressed rat corpora lutea

1988 ◽  
Vol 66 (1) ◽  
pp. 76-79 ◽  
Author(s):  
John C. M. Riley ◽  
John C. Carlson
Keyword(s):  
Plasma Membranes ◽  
Incubation Temperature ◽  
Binding Capacity ◽  
Single Point ◽  
Corpora Lutea ◽  
Binding Assays ◽  
Prostaglandin F ◽  
Membrane Bound ◽  
Membrane Bound Enzymes

The effect upon human chorionic gonadotropin (hCG) binding of a 90-min incubation of plasma membranes prepared from the corpora lutea of control and prostaglandin F2α injected rats was studied. After incubation for 90 min with 1 mM CaCl2 at 40 °C, single point hCG binding assays at room temperature revealed a significant decrease in the degree of binding of approximately 50% in membrane samples prepared from regressed corpora lutea. The binding decrease in regressed samples did not occur if the incubation temperature was reduced to 35 °C or if calcium ion was replaced with magnesium. Scatchard analyses indicated that the decrease in binding capacity was the result of a loss of gonadotropin receptors rather than an affinity shift. Specific activities of two membrane-bound enzymes (Na+–K+ ATPase, 5′-nucleotidase) did not change in a correlative fashion during the incubation. In previous studies the same in vitro conditions caused a substantial and significant decrease in membrane fluidity, as determined by fluorescence polarization. Thus it appears that the membrane rigidification is of a specific nature and interferes with gonadotropin binding during luteolysis.

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