scholarly journals Binding of monoclonal antibody AA4 to gangliosides on rat basophilic leukemia cells produces changes similar to those seen with Fc epsilon receptor activation.

1992 ◽  
Vol 116 (3) ◽  
pp. 635-646 ◽  
Author(s):  
C Oliver ◽  
N Sahara ◽  
S Kitani ◽  
A R Robbins ◽  
L M Mertz ◽  
...  
Keyword(s):  
Histamine Release ◽  
Calcium Ionophore ◽  
Receptor Activation ◽  
Calcium Ionophore A23187 ◽  
Rat Tissues ◽  
Ionophore A23187 ◽  
Ige Receptor ◽  
Culture Dish ◽  
Basophilic Leukemia

The mAb AA4 binds to novel derivatives of the ganglioside Gd1b on rat basophilic leukemia (RBL-2H3) cells. Some of the gangliosides are located close to the high affinity IgE receptor (Fc epsilon RI), and binding of mAb AA4 inhibits Fc epsilon RI-mediated histamine release. In the present study, mAb AA4 was found to bind exclusively to mast cells in all rat tissues examined. In vitro, within 1 min of mAb AA4 binding, the cells underwent striking morphologic changes. They lost their normal spindle shaped appearance, increased their ruffling, and spread over the surface of the culture dish. These changes were accompanied by a redistribution of the cytoskeletal elements, actin, tubulin, and vimentin, but only the actin was associated with the membrane ruffles. Binding of mAb AA4 also induces a rise in intracellular calcium, stimulates phosphatidyl inositol breakdown, and activates PKC. However, the extent of these changes was less than that observed when the cells were stimulated with antigen or antibody directed against the Fc epsilon RI. None of these changes associated with mAb AA4 binding were seen when the cells were exposed to nonspecific IgG, IgE, or four other anti-cell surface antibodies, nor were the changes induced by binding mAb AA4 at 4 degrees C or in the absence of extracellular calcium. Although mAb AA4 does not stimulate histamine release, it enhances the effect of the calcium ionophore A23187 mediated release. The morphological and biochemical effects produced by mAb AA4 are similar to those seen following activation of the cell through the IgE receptor. Therefore, the surface gangliosides which bind mAb AA4 may function in modulating secretory events.

Isolation and development of the inner cell mass after exposure of mouse embryos to calcium ionophore A23187

Development ◽  
1978 ◽  
Vol 45 (1) ◽  
pp. 237-247
Author(s):  
M. Azim H. Surani ◽  
David Torchiana ◽  
Sheila C. Barton
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Embryoid Bodies ◽  
Detectable Effect ◽  
Ionophore A23187 ◽  
Culture Dish

Compacted morulae and blastocysts were obtained from CBA, BALB/c and CFLP strains of mice. The embryos were incubated in medium containing 2 × 10−5 M or 2 × 10−6 M ionophore A 23187. With 2 × 10−6 M ionophore, morulae survived for up to 12 h showing slight decompaction. Normal development resumed when the morulae were explanted to fresh medium. There was no detectable effect on blastocysts. With 2 × 10−5 M ionophore, morulae survived for about 20 min and then extensive cell death occurred after this time. With blastocysts however, selective lysis of trophectoderm cells occurred after approximately 30 min following their swelling and vesiculation but the inner cell mass cells (ICM) remained apparently intact and viable. Nearly 80% of the early blastocysts obtained 87 h postovulation and all of the late blastocysts used after 12 h in culture (99 h blastocysts) showed this response. Individual fluid accumulating cells were detected in a few isolated ICMs after their overnight culture in vitro, especially in those obtained from early blastocysts, but the majority of the ICMs did not have these cells. All aggregates of three to five ICMs, except one which reformed into a blastocyst, developed as embryoid bodies after 2 days in culture and these survived for up to 10 days; in some cases they developed into cystic embryoid bodies or attached to the culture dish displaying a variety of cell types. The development of the isolated ICMs in vivo was judged to be normal after their transfer to intact host blastocysts as these developed as chimaeric embryos to term.

Andalusol, a Diterpenoid with anti-inflammatory Activity from Siderits foetens Clemen

1997 ◽  
Vol 52 (11-12) ◽  
pp. 844-849 ◽  
Author(s):  
A. Navarro ◽  
B. de las Heras
Keyword(s):  
Mast Cells ◽  
Histamine Release ◽  
Calcium Ionophore ◽  
Topical Administration ◽  
Calcium Ionophore A23187 ◽  
Inflammatory Activity ◽  
Specific Marker ◽  
Ionophore A23187 ◽  
Anti Inflammatory

Abstract The anti-inflammatory activity of andalusol (ent-13(16),14-labdadiene-6α,8α,18-triol), a diterpenoid obtained from the acetone extract of Sideritis foetens Clemen, has been investigated. This compound was able to inhibit acute inflammatory processes induced by carrageenan or 12-O -tetradecanoylphorbol acetate (TPA ) after oral or topical administration. Quantitation of the neutrophil specific marker, myeloperoxidase (MPO), demonstrated that its topical anti-inflammatory effect was associated with reduction in neutrophil infiltration into inflamed tissues. Interaction of andalusol with leukocyte functions and histamine release from mast cells was analyzed in vitro. At a concentration of 100 μm andalusol decreased β-glucuronidase release from calcium ionophore A23187-stimulated rat peritoneal leukocytes. However, it failed to affect superoxide generation on TPA -stimulated leukocytes and it was non toxic to leukocytes up to 100 μm (assayed in terms of lactate dehydrogenase release). Andalusol produced a dose-dependent inhibition on histamine release from rat peritoneal mast cells stimulated by com pound 48/80 or calcium ionophore A23187. These results suggest that andalusol possesses an anti-inflammatory profile, and it is in part responsible for the anti-inflammatory activity attributed to this plant.

Inhibition of Platelet Aggregation by Ethanol in Vitro Shows Specificity for Aggregating Agent Used and Is Influenced by Platelet Lipid Composition

1982 ◽  
Vol 48 (01) ◽  
pp. 049-053 ◽  
Author(s):  
C G Fenn ◽  
J M Littleton
Keyword(s):  
Platelet Aggregation ◽  
Lipid Composition ◽  
Saturated Fatty Acids ◽  
Calcium Ionophore ◽  
Cholesterol Content ◽  
Membrane Lipid ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Increased Sensitivity

SummaryEthanol at physiologically tolerable concentrations inhibited platelet aggregation in vitro in a relatively specific way, which may be influenced by platelet membrane lipid composition. Aggregation to collagen, calcium ionophore A23187 and thrombin (low doses) were often markedly inhibited by ethanol, adrenaline and ADP responses were little affected, and aggregation to exogenous arachidonic acid was actually potentiated by ethanol. Aggregation to collagen, thrombin and A23187 was inhibited more by ethanol in platelets enriched with saturated fatty acids than in those enriched with unsaturated fats. Platelets enriched with cholesterol showed increased sensitivity to ADP, arachidonate and adrenaline but this increase in cholesterol content did not appear to influence the inhibition by ethanol of platelet responses. The results suggest that ethanol may inhibit aggregation by an effect on membrane fluidity and/or calcium mobilization resulting in decreased activity of a membrane-bound phospholipase.

Immunologic mast cell-mediated responses and histamine release are attenuated by heparin

1992 ◽  
Vol 73 (3) ◽  
pp. 1093-1101 ◽  
Author(s):  
J. Lucio ◽  
J. D'Brot ◽  
C. B. Guo ◽  
W. M. Abraham ◽  
L. M. Lichtenstein ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Histamine Release ◽  
Immunoglobulin E ◽  
Specific Antigen ◽  
Calcium Ionophore ◽  
Intradermal Injection ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Dependent Manner

Heparin has been shown to act as a competitive inhibitor of inositol 1,4,5-triphosphate (InsP3) receptors in various cell types. Because InsP3 is one of the second messengers involved in stimulus-secretion coupling in mast cells, it is possible that heparin may inhibit mast cell-mediated reactions. Therefore, in allergic sheep, we tested this hypothesis in two mast cell-mediated reactions induced by immunologic and nonimmunologic stimuli: immediate cutaneous reaction (ICR) and acute bronchoconstrictor response (ABR). In 12 sheep allergic to Ascaris suum antigen, the surface area of the skin wheal was determined 20 min after intradermal injection (0.05 ml) of increasing concentrations of specific antigen, compound 48/80, and histamine, without and after pretreatment with heparin (100, 300, or 1,000 U/kg i.v.). Antigen, compound 48/80, and histamine produced concentration-dependent increases in ICR. Heparin “partially” inhibited the ICR to antigen and compound 48/80 in a dose-dependent manner without modifying the ICR to histamine. The heparin preservative benzyl alcohol was ineffective. In 11 additional sheep, specific lung resistance was measured before and after inhalation challenges with antigen, compound 48/80, and histamine without and with aerosol heparin pretreatment (1,000 U/kg). Heparin blocked the antigen- and compound 48/80-induced bronchoconstriction without modifying the airway effects of histamine. In isolated human uterine mast cells, heparin inhibited the anti-immunoglobulin E- but not the calcium ionophore- (A23187) induced histamine release. These data suggest that heparin inhibits the ICR and ABR induced by stimuli that produce immunologic and nonimmunologic mast cell degranulation without attenuating the effects of histamine.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Immunophenotyping and functional analysis of purified human uterine mast cells

Blood ◽  
1992 ◽  
Vol 79 (3) ◽  
pp. 708-712 ◽  
Author(s):  
CB Guo ◽  
A Kagey-Sobotka ◽  
LM Lichtenstein ◽  
BS Bochner
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Histamine Release ◽  
Umbilical Vein ◽  
Interleukin 1 ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Cell Heterogeneity ◽  
Mast Cell Heterogeneity

Abstract Human mast cells have been purified from uterine tissues, and their surface marker profile and function have been evaluated as part of ongoing studies of mast cell heterogeneity. Using a panel of antibodies, purified uterine mast cells (UMC; 81% +/- 7% purity, n = 10) were analyzed by immunofluorescence and flow cytometry for surface expression of various antigens. Consistent with previous analyses of mast cells from other tissues, UMC expressed HLA class I, IgE, c-kit receptor, CD9, CD33, CD43, CD45, and CD54, while CD11a, CD11b, CD14, CD16, CD23, and CD64 were not detected. Unlike other mast cells, UMC expressed CD11c/CD18 (p150,95) and CD32 (Fc gamma RII). Additional antigens not previously studied on mast cells included the selectin LECAM-1 (Leu-8) and several beta 1 and beta 3 integrins; expression of very late activation antigen-4 (VLA-4) (CD49d/CD29), VLA-5 (CD49e/CD29), and the vitronectin receptor (CD51/CD61) was seen. Functional studies showed that treatment of human umbilical vein endothelial cells with interleukin-1 (5 ng/mL for 4 hours) resulted in a twofold to threefold increase in adhesiveness for UMC. Purification procedures did not alter histamine release responses to anti-IgE or the calcium ionophore A23187, and treatment of UMC with an anti-CD32 monoclonal antibody (IV.3) did not induce histamine release or alter anti-IgE-induced release. These data suggest that UMC may possess unique phenotypic characteristics, and support the concept of mast cell heterogeneity.

Platelet microparticle membranes have 50- to 100-fold higher specific procoagulant activity than activated platelets

2007 ◽  
Vol 97 (03) ◽  
pp. 425-434 ◽  
Author(s):  
Dmitry Kireev ◽  
Nadezhda Popenko ◽  
Aleksei Pichugin ◽  
Mikhail Panteleev ◽  
Olga Krymskaya ◽  
...  
Keyword(s):  
Blood Platelets ◽  
Calcium Ionophore ◽  
Coagulation Factors ◽  
In Vitro Models ◽  
Calcium Ionophore A23187 ◽  
Procoagulant Activity ◽  
Ionophore A23187 ◽  
Factor X ◽  
Activated Platelets

SummaryPlatelet microparticles (PMPs) are small vesicles released from blood platelets upon activation. The procoagulant activity of PMPs has been previously mainly characterized by theirability to bind coagulation factors VIII and Va in reconstructed systems. It can be supposed that PMPs can contribute to the development of thrombotic complications in the pathologic states associated with the increase of their blood concentration. In this study we compared procoagulant properties of calcium ionophore A23187-activated platelets and PMPs using several in-vitro models of hemostasis. Surface densities of phosphatidylserine, CD61, CD62P and factor X bound per surface area unit were determined by flow cytometry. They were 2.7-, 8.4-, 4.3-, and 13-fold higher for PMPs than for activated platelets, respectively. Spatial clot growth rate (Vclot) in the reaction-diffus ion experimental model and endogenous thrombin potential (ETP) were determined in plasma, which was depleted of phospholipid cell surfaces by ultra-centrifugation and supplemented with activated platelets or PMPs at different concentrations. Both Vcllot and ETP rapidly increased with the increase of PMP or platelet concentration until saturation was reached. The plateau values of Vclot and ETP for activated platelets and PMPs were similar. In both assays, the procoagulant activity of one PMP was almost equal to that of one activated platelet despite at least two-orders-of-magnitude difference in their surface areas. This suggests that the PMP surface is approximately 50- to 100-fold more procoagulant than the surface of activated platelets.

scholarly journals MiR-302e attenuates allergic inflammation in vitro model by targeting RelA

2018 ◽  
Vol 38 (3) ◽  
Author(s):  
Lifeng Xiao ◽  
Li Jiang ◽  
Qi Hu ◽  
Yuru Li
Keyword(s):  
Inflammatory Cytokines ◽  
Luciferase Activity ◽  
Allergic Inflammation ◽  
Calcium Ionophore ◽  
Allergic Diseases ◽  
Calcium Ionophore A23187 ◽  
Human Mast Cell ◽  
Ionophore A23187 ◽  
Down Regulation

Allergic inflammation is the foundation of allergic rhinitis and asthma. Although microRNAs are implicated in the pathogenesis of various diseases, information regarding the functional role of microRNAs in allergic diseases is limited. Herein, we reported that microRNA-302e (miR-302e) serves as an important regulator of allergic inflammation in human mast cell line, HMC-1 cells. Our results showed that miR-302e is the dominant member of miR-302 family expressed in HMC-1 cells. Moreover, the expression of miR-302e was significantly decreased in response to phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187 or ovalbumin (OVA) stimulation. Overexpression of miR-302e blocked PMA/A23187 or OVA induced the increase in inflammatory cytokines levels, such as IL-1β, IL-6, tumor necrosis factor (TNF)-α and thymic stromal lymphopoietin, while miR-302 inhibition further promoted the release of these cytokines. Mechanistically, we found that miR-302e is a novel miRNA that targets RelA, a gene known to be involved in regulating inflammation, through binding to the 3′-UTR of RelA mRNA. Ectopic miR-302e remarkably suppressed the luciferase activity and expression of RelA, whereas down-regulation of miR-302e increased RelA luciferase activity and expression. Pharmacological inhibition of NF-κB reversed the augmented effect of miR-302e down-regulation on inflammatory cytokines level. Taken together, the present study demonstrates miR-302e limits allergic inflammation through inhibition of NF-κB activation, suggesting miR-302e may play an anti-inflammatory role in allergic diseases and function as a novel therapeutic target for the treatment of these diseases.

scholarly journals Prevention of calpain-dependent degradation of STK38 by MEKK2-mediated phosphorylation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Atsushi Enomoto ◽  
Takemichi Fukasawa ◽  
Hiroki Tsumoto ◽  
Masataka Karube ◽  
Keiichi Nakagawa ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Terminal Region ◽  
Calpain Inhibitor ◽  
Ionophore A23187 ◽  
Serine Threonine Kinase ◽  
Defective Mutant ◽  
Cleavage Assay

Abstract Serine-threonine kinase 38 (STK38) is a member of the protein kinase A (PKA)/PKG/PKC-family implicated in the regulation of cell division and morphogenesis. However, the molecular mechanisms underlying STK38 stability remain largely unknown. Here, we show that treatment of cells with either heat or the calcium ionophore A23187 induced STK38 degradation. The calpain inhibitor calpeptin suppressed hyperthermia-induced degradation or the appearance of A23187-induced cleaved form of STK38. An in vitro cleavage assay was then used to demonstrate that calpain I directly cleaves STK38 at the proximal N-terminal region. Deletion of the N-terminal region of STK38 increased its stability against hyperthermia. We further demonstrated that the MAPKK kinase (MAP3K) MEKK2 prevented both heat- and calpain-induced cleavage of STK38. MEKK2 knockdown enhanced hyperthermia-induced degradation of STK38. We performed an in vitro MEKK2 assay and identified the key regulatory site in STK38 phosphorylated by MEKK2. Experiments with a phosphorylation-defective mutant demonstrated that phosphorylation of Ser 91 is important for STK38 stability, as the enzyme is susceptible to degradation by the calpain pathway unless this residue is phosphorylated. In summary, we demonstrated that STK38 is a calpain substrate and revealed a novel role of MEKK2 in the process of STK38 degradation by calpain.

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