scholarly journals Lipopolysaccharide priming of human neutrophils for an enhanced respiratory burst. Role of intracellular free calcium.

1989 ◽  
Vol 83 (1) ◽  
pp. 74-83 ◽  
Author(s):  
J R Forehand ◽  
M J Pabst ◽  
W A Phillips ◽  
R B Johnston
Keyword(s):  
Respiratory Burst ◽  
Intracellular Free Calcium ◽  
Human Neutrophils ◽  
Free Calcium

Recombinant human MCP-1/JE induces chemotaxis, calcium flux, and the respiratory burst in human monocytes

Blood ◽  
1991 ◽  
Vol 78 (4) ◽  
pp. 1112-1116 ◽  
Author(s):  
BJ Rollins ◽  
A Walz ◽  
M Baggiolini
Keyword(s):  
Growth Factor ◽  
Respiratory Burst ◽  
Specific Activity ◽  
Calcium Flux ◽  
Human Neutrophils ◽  
Free Calcium ◽  
Secretory Proteins ◽  
Predicted Amino Acid Sequence ◽  
Human Monocytes ◽  
Inducible Gene

Abstract The JE gene was first described as a platelet-derived growth factor (PDGF)-inducible gene in mouse 3T3 cells. The human homologue of JE encodes a protein whose predicted amino acid sequence is identical to that of the monocyte chemoattractant MCP-1 (also called MCAF and SMC- CF), which belongs to a recently identified family of small secretory proteins with cytokine properties. We purified recombinant human MCP- 1/JE (hMCP-1/JE) produced in COS cells and demonstrated that it is chemotactic for human monocytes with a specific activity similar to natural MCP-1. In addition, pure recombinant hMCP-1/JE stimulates monocytes, inducing an increase in cytosolic free calcium and the respiratory burst, but is completely inactive on human neutrophils. These results help to define functionally a well-known growth factor- inducible gene and a member of a new family of cytokines.

Cholinergic effects on intracellular free calcium concentration in renal corpuscle: role of parietal sheet

1992 ◽  
Vol 262 (2) ◽  
pp. F248-F255
Author(s):  
F. Lebrun ◽  
F. Morel ◽  
G. Vassent ◽  
J. Marchetti
Keyword(s):  
Calcium Release ◽  
Intracellular Free Calcium ◽  
Free Calcium ◽  
Response Curves ◽  
Glomerular Function ◽  
Intracellular Free Calcium Concentration ◽  
Free Calcium Concentration ◽  
External Calcium ◽  
Cholinergic Effects

To investigate a possible effect of cholinergic agonists on the renal glomerular function, fura-2 microfluorometric measurements of intracellular free calcium [( Ca2+]i) were performed on single intact glomeruli, single isolated parietal sheets of the Bowman's capsule and single parietal sheet-deprived glomeruli (PS-D glomerulus). Carbachol (10(-4) M), in the presence of 2 mM external calcium, induced a biphasic increase in [Ca2+]i characterized by a sharp initial peak followed by a sustained plateau in the whole glomerulus (delta [Ca2+]i = 177 +/- 13 and 70 +/- 7 nM, respectively; n = 21) and in the parietal sheet (418 +/- 30 and 111 +/- 13 nM, respectively; n = 21). In the PS-D glomerulus (n = 9), the response was less marked and included a barely visible peak (77 +/- 13 nM) and a relatively low plateau (49 +/- 11 nM). In the absence of external calcium, the peak phase was preserved in the three structures, indicating a calcium release from intracellular pools, whereas the plateau, due to the entry of external calcium, was suppressed. These effects were fully inhibited by 10(-4) M of either atropine or pirenzepine, demonstrating the muscarinic nature of the receptors. Dose-response curves showed that the parietal sheet was more sensitive to the physiological agonist (acetylcholine) than to carbachol. A still unexplained difference in sensitivity was noted between peak and plateau, respectively (half-maximal responses were 5 x 10(-6) vs. 5 x 10(-7) M for carbachol and 2 x 10(-7) vs. 3 x 10(-8) M for acetylcholine).(ABSTRACT TRUNCATED AT 250 WORDS)

Source and role of diacylglycerol formed during phagocytosis of opsonized yeast particles and associated respiratory burst in human neutrophils

1991 ◽  
Vol 177 (3) ◽  
pp. 948-955 ◽  
Author(s):  
Vittorina Della Bianca ◽  
Miroslawa Grzeskowiak ◽  
Daniele Lissandrini ◽  
Filippo Rossi
Keyword(s):  
Respiratory Burst ◽  
Human Neutrophils

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.

Stimulation of the Mineralocorticoid Receptor by Aldosterone Leads to Activation of HL-60 Neutrophils,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3206-3206
Author(s):  
Carlos E Vazquez ◽  
Gregory N Prado ◽  
Enrique R Maldonado ◽  
Gabriela Saca ◽  
Iren M Ortiz ◽  
...  
Keyword(s):  
Western Blot ◽  
Respiratory Burst ◽  
Mineralocorticoid Receptor ◽  
Conflicts Of Interest ◽  
Critical Role ◽  
Neutrophil Activation ◽  
Human Neutrophils ◽  
Dead Cell ◽  
Cardiovascular Morbidity And Mortality

Abstract Abstract 3206 Blockade of the mineralocorticoid receptor (MR), the receptor for aldosterone (ALDO), improves cardiovascular morbidity and mortality. There is growing evidence for a critical role of ALDO in inflammation in addition to its well-described effects on sodium homeostasis. However, the role of ALDO on neutrophil activation is not entirely clear. We studied the role of ALDO on HL-60, a human promyelocytic cell line, induced to differentiate into neutrophil-like cells by incubation for 3 days with 1.3% DMSO. We detected the presence of the mineralocorticoid receptor (MR), the receptor for ALDO, by western blot analyses and MR transcript by quantitative RT-PCR using TaqMan detection probes in these cells. Cells incubated with ALDO (10−8-10−7 M) showed a dose-dependent rise in cytosolic Ca2+ that peaked within 3 min using FURA-2AM fluorescence; an event not observed when cells were incubated with 10−8 M dexamethasone (DEXA). Consistent with these results, incubation with 10−8 M ALDO led to increases in the oxidative-respiratory burst [superoxide production] (P<0.01, n=3); an event not observed when cells were incubated with either 10−8 or 10−7 M dexamethasone. The oxidative responses to ALDO were blunted by pre-incubation of cells with 1 uM canrenoic acid (CA), a well-described MR antagonist (P<0.03, n=3). We then studied the effect of ALDO on HL-60 transmigration and observed that 2 hr incubation at 37C with 10−8 M ALDO led to augmented migration (P<0.03, n=2) when compared to vehicle as estimated by CyQuant cell migration assays. We then isolated untouched circulating human neutrophils by immunomagnetic isolation following density gradient sedimentation with PolymorphPrep from otherwise healthy subjects. Flow cytometric analyses showed greater than 97% neutrophils as these cells were positive for CD45, CD16 and CD66b. Live/dead cell automated analyses shows greater than 90% cell viability by acridine orange and propidium iodide fluorescence. These cells likewise express MR as determined by western blot analyses for MR as reported in kidney and endothelial cells. Cells incubated with ALDO (10−8 M) showed a rise in cytosolic Ca2+ and an increase in the oxidative-respiratory burst (P<0.01, n=3); a response that was sensitive to 1 uM CA. We also observed that 4 hr 10−9M ALDO incubation led to augmented neutrophil transmigration (P<0.03, n=2). Thus our results suggest that activation of MR by ALDO leads to neutrophil activation that may contribute to the inflammatory responses associated with MR activation in vivo. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Regulation of superoxide generation by myeloperoxidase during the respiratory burst of human neutrophils

1986 ◽  
Vol 237 (2) ◽  
pp. 601-604 ◽  
Author(s):  
S W Edwards ◽  
T F Swan
Keyword(s):  
Respiratory Burst ◽  
Cytochalasin B ◽  
Superoxide Radical ◽  
Human Neutrophils ◽  
Second Phase ◽  
Chemotactic Peptide ◽  
O2 Uptake ◽  
Superoxide Generation ◽  
Lower Magnitude

The role of myeloperoxidase in the regulation of the respiratory burst of human neutrophils activated by the chemotactic peptide (N-formyl-L-methionyl-L-leucyl-L-phenylalanine) plus cytochalasin B was determined by using anti-(human myeloperoxidase) antibody. The respiratory burst activated under these conditions consisted of an initial (1-2 min) phase with high rates of O2 uptake, luminol-dependent chemiluminescence and superoxide radical (O2-.) generation and a second, more sustained, phase of lower magnitude of chemiluminescence and O2 uptake: O2-. generation did not occur during this second phase. In cell suspensions stimulated in the presence of anti-(human myeloperoxidase) antibody, the magnitude of the initial phase of both O2 uptake and O2-. generation was unaffected, but these high rates were maintained over much longer periods than in control suspensions. It is therefore proposed that a product of myeloperoxidase normally regulates the duration of O2-. generation during the respiratory burst, possibly by inhibition of NADPH oxidase.

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