Inhibitory effect of interleukin-8 on the secretion of platelet-activating factor acetylhydrolase by human decidual macrophages.
OBJECTIVE
To determine whether interleukin-8 (IL-8) regulates platelet-activating factor acetylhydrolase (PAF-AH) secretion by decidual cells in vitro.


METHODS
Decidual macrophages were obtained from human term decidual tissue by enzymic digestion and Ficoll-Paque centrifugation. The effect of IL-8 and phorbol esters on the secretion of PAF-acetylhydrolase by these cells was examined.


RESULTS
IL-8 inhibited PAF-AH secretion by decidual macrophages in a dose-dependent manner. The inhibition was reversed partially by antibodies against tumor necrosis factor-alpha and IL-1 beta. IL-8-induced inhibition was blocked partially by the protein kinase C (PKC) inhibitors, sphingosine, and H-7 1-(5-isoquinoline sulfonyl)-2-methylpiperazine. A PKC activator, 12-O-tetradecanoyl phorbol 13-acetate, decreased PAF-AH secretion.


CONCLUSIONS
IL-8 may increase the PAF concentration in the decidua via its inhibitory effect on PAF-AH secretion by decidual macrophages. IL-8-induced inhibition of enzyme secretion may have been mediated in part by PKC-dependent signal transduction.
Kawano
Y
Y
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9051, USA.
Narahara
H
H
Johnston
J M
JM
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D000906:Antibodies / Q000494:pharmacology; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D003656:Decidua / Q000166:cytology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000037:antagonists & inhibitors; D016209:Interleukin-8 / Q000008:administration & dosage / Q000494:pharmacology*; D007743:Labor, Obstetric / Q000502:physiology; D008264:Macrophages / Q000201:enzymology*; D010741:Phospholipases A / Q000378:metabolism* / Q000502:physiology; D011247:Pregnancy; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D013110:Sphingosine / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
D000906:Antibodies; D017077:Culture Media, Conditioned; D004791:Enzyme Inhibitors; D007375:Interleukin-1; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D010741:Phospholipases A; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D013110:Sphingosine; D013755:Tetradecanoylphorbol Acetate