Mechanism of polymorphonuclear leukocyte activation by myristate. Involvement of calcium ion and protein kinase C.

Yamamoto, Masazumi; Okimasu, Eiji; Terada, Sigeo; Utsumi, Kozo

doi:10.1247/csf.12.357

Cited by 5 publications

(1 citation statement)

References 27 publications

(4 reference statements)

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“…However, PMA stimulation did not increase in MLCK activity, which is regulated by Ca 2+ /calmodulin (Totsukawa et al 2000). This finding is supported by the facts demonstrating that PMA stimulation of human neutrophils does not induce any increase in the level of intracellular Ca 2+ concentration (Christiansen et al 1986;Yamamoto et al 1987).…”

Section: Upregulation Of Alpase Activitysupporting

confidence: 64%

ML-7 inhibits exocytosis of superoxide-producing intracellular compartments in human neutrophils stimulated with phorbol myristate acetate in a myosin light chain kinase-independent manner

Odani

Kobayashi

Ogawa

et al. 2003

Histochem Cell Biol

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ML-7, (5-iodonaphthalene-1-sulfonyl) homopiperazine, is commonly employed as a myosin light chain kinase (MLCK) inhibitor. In the present study, we demonstrated that ML-7 affects the superoxide (O 2 )producing system of human neutrophils in an MLCKindependent manner. Human neutrophils were stimulated with phorbol myristate acetate (PMA), which does not activate MLCK. ML-7 inhibited extracellular release, but not intracellular production of O 2 in the stimulated cells. Fluorescence microscopy revealed the generation of O 2 at intracellular compartments in the stimulated cells exposed to ML-7. At the electron microscopic level, the reaction product of NADPH oxidase activity was found in intracellular compartments. ML-7 strongly inhibited the association of the oxidant-producing intracellular compartments with the plasma membrane. Furthermore, the upregulation of alkaline phosphatase activity, a marker enzyme of the oxidant-producing intracellular compartments, was also inhibited by ML-7. These findings indicate that ML-7 inhibits the fusion of the oxidantproducing intracellular compartments to the plasma membrane resulting in the inhibition of the extracellular release of O 2 in PMA-stimulated human neutrophils in an MLCK-independent manner.

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Section: Upregulation Of Alpase Activitysupporting

confidence: 64%

ML-7 inhibits exocytosis of superoxide-producing intracellular compartments in human neutrophils stimulated with phorbol myristate acetate in a myosin light chain kinase-independent manner

Odani

Kobayashi

Ogawa

et al. 2003

Histochem Cell Biol

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A comparison of the priming effect of phorbol myristate acetate and phorbol dibutyrate on fMet-Leu-Phe-induced oxidative burst in human neutrophils

Gaudry¹,

Combadière²,

Marquetty³

et al. 1990

Immunopharmacology

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Inhibition of gap junction-mediated intercellular communication by alpha-linolenate

Hasler

Bennink

Trosko

1991

American Journal of Physiology-Cell Physiology

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The purpose of this investigation was to assess whether alterations in the fatty acid composition of rat liver epithelial (WB-F344) cell phospholipids would modulate gap junction-mediated intercellular communication (GJIC). WB-F344 cells were grown to confluency in culture medium supplemented with one of seven different fatty acids at a concentration of 50 microM for 48 h. Only alpha-linoleate (18:3 n-3) significantly inhibited GJIC. Saturated fatty acids (12:0, 16:0, and 18:0), a monounsaturated fatty acid (18:1 n-9), and n-6 polyunsaturated fatty acids (18:2 and 20:4) did not affect GJIC. The alpha-linolenate-induced inhibition of GJIC was not due to the activation of protein kinase C or intracellular hydroperoxide production, two lipid-dependent parameters previously shown to inhibit GJIC. In addition, alpha-linolenate did not alter membrane fluidity. Although the mechanism by which alpha-linolenate inhibits GJIC is unclear, changes in the fatty acid composition of cell phospholipids may be of critical importance. Subsequent to supplementation with alpha-linolenate, WB-F344 cell phospholipids had reduced 20:4 n-6 and elevated n-3 fatty acids. The results of this investigation emphasize the importance of current research into the influence of lipids on cell function and identify a new mechanism by which gap junctions can be modulated.

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Mechanism of polymorphonuclear leukocyte activation by myristate. Involvement of calcium ion and protein kinase C.

Cited by 5 publications

References 27 publications

ML-7 inhibits exocytosis of superoxide-producing intracellular compartments in human neutrophils stimulated with phorbol myristate acetate in a myosin light chain kinase-independent manner

ML-7 inhibits exocytosis of superoxide-producing intracellular compartments in human neutrophils stimulated with phorbol myristate acetate in a myosin light chain kinase-independent manner

A comparison of the priming effect of phorbol myristate acetate and phorbol dibutyrate on fMet-Leu-Phe-induced oxidative burst in human neutrophils

Inhibition of gap junction-mediated intercellular communication by alpha-linolenate

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