scholarly journals Novel polyisoprenyl phosphates block phospholipase D and human neutrophil activation in vitro and murine peritoneal inflammation in vivo

2005 ◽  
Vol 146 (3) ◽  
pp. 344-351 ◽  
Author(s):  
Bruce D Levy ◽  
Lorraine Hickey ◽  
Andrew J Morris ◽  
Mykol Larvie ◽  
Raquel Keledjian ◽  
...  
Keyword(s):  
Phospholipase D ◽  
Human Neutrophil ◽  
Neutrophil Activation ◽  
Peritoneal Inflammation

Neutrophil activation by heme: implications for inflammatory processes

Blood ◽  
2002 ◽  
Vol 99 (11) ◽  
pp. 4160-4165 ◽  
Author(s):  
Aurélio V. Graça-Souza ◽  
Maria Augusta B. Arruda ◽  
Marta S. de Freitas ◽  
Christina Barja-Fidalgo ◽  
Pedro L. Oliveira
Keyword(s):  
Human Neutrophil ◽  
Actin Polymerization ◽  
Neutrophil Activation ◽  
Polymorphonuclear Neutrophil ◽  
Human Neutrophils ◽  
Cytoskeleton Reorganization ◽  
Proinflammatory Molecule ◽  
Inflammatory Processes

Heme, a ubiquitous iron-containing compound, is present in large amounts in many cells and is inherently dangerous, particularly when it escapes from intracellular sites. The release of heme from damaged cells and tissues is supposed to be higher in diseases such as malaria and hemolytic anemia or in trauma and hemorrhage. We investigated here the role of free ferriprotoporphyrin IX (hemin) as a proinflammatory molecule, with particular attention to its ability to activate neutrophil responses. Injecting hemin into the rat pleural cavity resulted in a dose-dependent migration of neutrophils, indicating that hemin is able to promote the recruitment of these cells in vivo. In vitro, hemin induced human neutrophil chemotaxis and cytoskeleton reorganization, as revealed by the increase of neutrophil actin polymerization. Exposure of human neutrophils to 3 μM hemin activated the expression of the chemokine interleukin-8, as demonstrated by quantitative reverse-transcription polymerase chain reaction, indicating a putative molecular mechanism by which hemin induces chemotaxis in vivo. Brief incubation of human neutrophils with micromolar concentrations of hemin (1-20 μM) triggered the oxidative burst, and the production of reactive oxygen species was directly proportional to the concentration of hemin added to the cells. Finally, we observed that human neutrophil protein kinase C was activated by hemin in vitro, with a K1/2 of 5 μM. Taken together, these results suggest a role for hemin as a proinflammatory agent able to induce polymorphonuclear neutrophil activation in situations of clinical relevance, such as hemolysis or hemoglobinemia.

Involvement of SNAP-23 and syntaxin 6 in human neutrophil exocytosis

Blood ◽  
2000 ◽  
Vol 96 (7) ◽  
pp. 2574-2583 ◽  
Author(s):  
Belén Martı́n-Martı́n ◽  
Svetlana M. Nabokina ◽  
Juan Blasi ◽  
Pedro A. Lazo ◽  
Faustino Mollinedo
Keyword(s):  
Human Neutrophil ◽  
Coiled Coil ◽  
Neutrophil Activation ◽  
Human Neutrophils ◽  
Binding Studies ◽  
Specific Granules ◽  
Neutrophil Degranulation ◽  
Carboxy Terminal

Abstract To understand the molecular basis of exocytosis in human neutrophils, the role of syntaxin 6 and SNAP-23 in neutrophil degranulation was examined. Human syntaxin 6 was cloned and identified as a 255-amino acid protein with a carboxy-terminal transmembrane region and two coiled-coil domains. Syntaxin 6 was localized mainly in the plasma membrane of human resting neutrophils, whereas SNAP-23 was located primarily in the mobilizable tertiary and specific granules. SNAP-23 was translocated to the cell surface, colocalizing with syntaxin 6, on neutrophil activation. In vitro binding studies established that SNAP-23 binds to syntaxin 6. Coimmunoprecipitation assays indicated that SNAP-23 interacts with syntaxin 6 in vivo, and this interaction was dramatically increased on neutrophil activation. Antibodies against SNAP-23 inhibited Ca++ and GTP-γ-S–induced exocytosis of CD67-enriched specific granules, but they hardly affected exocytosis of the CD63-enriched azurophilic granules, when introduced into electropermeabilized neutrophils. Anti–syntaxin 6 antibodies prevented exocytosis of both CD67- and CD63-enriched granules in electropermeabilized neutrophils. These data show that syntaxin 6 and SNAP-23 are involved in human neutrophil exocytosis, demonstrating that vesicle SNAP receptor-target SNAP receptor (v-SNARE– t-SNARE) interactions modulate neutrophil secretion. Syntaxin 6 acts as a target for secretion of specific and azurophilic granules, whereas SNAP-23 mediates specific granule secretion.

Involvement of SNAP-23 and syntaxin 6 in human neutrophil exocytosis

Blood ◽  
2000 ◽  
Vol 96 (7) ◽  
pp. 2574-2583 ◽  
Author(s):  
Belén Martı́n-Martı́n ◽  
Svetlana M. Nabokina ◽  
Juan Blasi ◽  
Pedro A. Lazo ◽  
Faustino Mollinedo
Keyword(s):  
Human Neutrophil ◽  
Coiled Coil ◽  
Neutrophil Activation ◽  
Human Neutrophils ◽  
Binding Studies ◽  
Specific Granules ◽  
Neutrophil Degranulation ◽  
Carboxy Terminal

To understand the molecular basis of exocytosis in human neutrophils, the role of syntaxin 6 and SNAP-23 in neutrophil degranulation was examined. Human syntaxin 6 was cloned and identified as a 255-amino acid protein with a carboxy-terminal transmembrane region and two coiled-coil domains. Syntaxin 6 was localized mainly in the plasma membrane of human resting neutrophils, whereas SNAP-23 was located primarily in the mobilizable tertiary and specific granules. SNAP-23 was translocated to the cell surface, colocalizing with syntaxin 6, on neutrophil activation. In vitro binding studies established that SNAP-23 binds to syntaxin 6. Coimmunoprecipitation assays indicated that SNAP-23 interacts with syntaxin 6 in vivo, and this interaction was dramatically increased on neutrophil activation. Antibodies against SNAP-23 inhibited Ca++ and GTP-γ-S–induced exocytosis of CD67-enriched specific granules, but they hardly affected exocytosis of the CD63-enriched azurophilic granules, when introduced into electropermeabilized neutrophils. Anti–syntaxin 6 antibodies prevented exocytosis of both CD67- and CD63-enriched granules in electropermeabilized neutrophils. These data show that syntaxin 6 and SNAP-23 are involved in human neutrophil exocytosis, demonstrating that vesicle SNAP receptor-target SNAP receptor (v-SNARE– t-SNARE) interactions modulate neutrophil secretion. Syntaxin 6 acts as a target for secretion of specific and azurophilic granules, whereas SNAP-23 mediates specific granule secretion.

Phospholipase D1b and D2a generate structurally identical phosphatidic acid species in mammalian cells

2001 ◽  
Vol 360 (3) ◽  
pp. 707-715 ◽  
Author(s):  
Trevor R. PETTITT ◽  
Mark McDERMOTT ◽  
Khalid M. SAQIB ◽  
Neil SHIMWELL ◽  
Michael J. O. WAKELAM
Keyword(s):  
Liquid Chromatography ◽  
Phosphatidic Acid ◽  
Phospholipase D ◽  
Mammalian Cells ◽  
Inducible Promoter ◽  
In Vitro Assays ◽  
Protein Levels ◽  
Intracellular Messenger

Mammalian cells contain different phospholipase D enzymes (PLDs) whose distinct physiological roles are poorly understood and whose products have not been characterized. The development of porcine aortic endothelial (PAE) cell lines able to overexpress PLD-1b or −2a under the control of an inducible promoter has enabled us to characterize both the substrate specificity and the phosphatidic acid (PtdOH) product of these enzymes under controlled conditions. Liquid chromatography–MS analysis showed that PLD1b- and PLD2a-transfected PAE cells, as well as COS7 and Rat1 cells, generate similar PtdOH and, in the presence of butan-1-ol, phosphatidylbutanol (PtdBut) profiles, enriched in mono- and di-unsaturated species, in particular 16:0/18:1. Although PtdBut mass increased, the species profile did not change in cells stimulated with ATP or PMA. Overexpression of PLD made little difference to basal or stimulated PtdBut formation, indicating that activity is tightly regulated in vivo and that factors other than just PLD protein levels limit hydrolytic function. In vitro assays using PLD-enriched lysates showed that the enzyme could utilize both phosphatidylcholine and, much less efficiently, phosphatidylethanolamine, with slight selectivity towards mono- and di-unsaturated species. Phosphatidylinositol was not a substrate. Thus PLD1b and PLD2a hydrolyse a structurally similar substrate pool to generate an identical PtdOH product enriched in mono- and di-unsaturated species that we propose to function as the intracellular messenger forms of this lipid.

scholarly journals Neutrophil activation in vitro and in vivo in Wegener's granulomatosis

1994 ◽  
Vol 45 (4) ◽  
pp. 1120-1131 ◽  
Author(s):  
Elisabeth Brouwer ◽  
Minke G. Huitema ◽  
A.H. Leontine Mulder ◽  
Peter Heeringa ◽  
Harry van Goor ◽  
...  
Keyword(s):  
Wegener’S Granulomatosis ◽  
Wegener's Granulomatosis ◽  
Neutrophil Activation

scholarly journals Kruppel-like factor 4 regulates neutrophil activation

2017 ◽  
Vol 1 (11) ◽  
pp. 662-668 ◽  
Author(s):  
Yuyan Shen ◽  
Hong Hong ◽  
Panjamaporn Sangwung ◽  
Stephanie Lapping ◽  
Lalitha Nayak ◽  
...  
Keyword(s):  
Crucial Role ◽  
Neutrophil Function ◽  
Neutrophil Activation ◽  
Key Points

Key Points KLF4 deficiency impairs neutrophil function in vitro and in vivo. This is the first demonstration that KLF4 plays a crucial role in neutrophils.

Peptidyl .alpha.-ketoheterocyclic inhibitors of human neutrophil elastase. 3. In vitro and in vivo potency of a series of peptidyl .alpha.-ketobenzoxazoles

1995 ◽  
Vol 38 (20) ◽  
pp. 3972-3982 ◽  
Author(s):  
Philip D. Edwards ◽  
Mark A. Zottola ◽  
Matthew Davis ◽  
Joseph Williams ◽  
Paul A. Tuthill
Keyword(s):  
Neutrophil Elastase ◽  
Human Neutrophil ◽  
Human Neutrophil Elastase

“Autoregulation” of Human Neutrophil Activation In Vitro: Regulation of Phorbol Myristate Acetate-Induced Neutrophil Activation by Cell Density

1990 ◽  
Vol 47 (5) ◽  
pp. 457-474 ◽  
Author(s):  
Stephen P. Peters ◽  
Franklin Cerasoli ◽  
Kurt H. Albertine ◽  
Marlys H. Gee ◽  
David Berd ◽  
...  
Keyword(s):  
Cell Density ◽  
Phorbol Myristate Acetate ◽  
Human Neutrophil ◽  
Neutrophil Activation ◽  
Myristate Acetate

scholarly journals Dual role for phosphoinositides in regulation of yeast and mammalian phospholipase D enzymes

2002 ◽  
Vol 159 (6) ◽  
pp. 1039-1049 ◽  
Author(s):  
Vicki A. Sciorra ◽  
Simon A. Rudge ◽  
Jiyao Wang ◽  
Stuart McLaughlin ◽  
JoAnne Engebrecht ◽  
...  
Keyword(s):  
Phospholipase D ◽  
Membrane Trafficking ◽  
Dual Role ◽  
Biological Functions ◽  
Ph Domain ◽  
Catalytically Active ◽  
Acidic Phospholipids ◽  
Stimulation Of

Phospholipase D (PLD) generates lipid signals that coordinate membrane trafficking with cellular signaling. PLD activity in vitro and in vivo is dependent on phosphoinositides with a vicinal 4,5-phosphate pair. Yeast and mammalian PLDs contain an NH2-terminal pleckstrin homology (PH) domain that has been speculated to specify both subcellular localization and regulation of PLD activity through interaction with phosphatidylinositol 4,5-bisphosphate (PI[4,5]P2). We report that mutation of the PH domains of yeast and mammalian PLD enzymes generates catalytically active PI(4,5)P2-regulated enzymes with impaired biological functions. Disruption of the PH domain of mammalian PLD2 results in relocalization of the protein from the PI(4,5)P2-containing plasma membrane to endosomes. As a result of this mislocalization, mutations within the PH domain render the protein unresponsive to activation in vivo. Furthermore, the integrity of the PH domain is vital for yeast PLD function in both meiosis and secretion. Binding of PLD2 to model membranes is enhanced by acidic phospholipids. Studies with PLD2-derived peptides suggest that this binding involves a previously identified polybasic motif that mediates activation of the enzyme by PI(4,5)P2. By comparison, the PLD2 PH domain binds PI(4,5)P2 with lower affinity but sufficient selectivity to function in concert with the polybasic motif to target the protein to PI(4,5)P2-rich membranes. Phosphoinositides therefore have a dual role in PLD regulation: membrane targeting mediated by the PH domain and stimulation of catalysis mediated by the polybasic motif.

Phospholipase D: enzymology, mechanisms of regulation, and function

1997 ◽  
Vol 77 (2) ◽  
pp. 303-320 ◽  
Author(s):  
J. H. Exton
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phosphatidic Acid ◽  
G Protein ◽  
Phospholipase D ◽  
Tyrosine Kinases ◽  
Rho Proteins ◽  
Kinase C

Phospholipase D exists in various forms that differ in their regulation but predominantly hydrolyze phosphatidylcholine. The Ca(2+)-dependent isozymes of protein kinase C regulate phospholipase D in vitro and play a major role in its control by growth factors and G protein-linked agonists in vivo. Recent studies have demonstrated that small G proteins of the ADP-ribosylation factor (ARF) and Rho families activate the enzyme in vitro, and evidence is accumulating that they also are involved in its control in vivo. Both types of G protein play important roles in cellular function, and the possible mechanisms by which they are activated by agonists are discussed. There is also emerging evidence of the control of phospholipase D and Rho proteins by soluble tyrosine kinases and novel serine/threonine kinases. The possible role of these kinases in agonist regulation of phospholipase D is discussed. The function of phospholipase D in cells is still poorly defined. Postulated roles of phosphatidic acid produced by phospholipase D action include the activation of Ca(2+)-independent isoforms of protein kinase C, the regulation of growth and the cytoskeleton in fibroblasts, and control of the respiratory burst in neutrophils. Another important function of phosphatidic acid is to act as a substrate for a specific phospholipase A2 to generate lysophosphatidic acid, which is becoming increasingly recognized as a major intercellular messenger. Finally, it is possible that the phospholipid changes induced in various cellular membranes by phospholipase D may per se play an important role in vesicle trafficking and other membrane-associated events.

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