当前位置： SCI文献检索 > ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS期刊下所有文献 > Secretion of platelet-activating factor acetylhydrolase following phorbol ester-stimulated differentiation of HL-60 cells.

Secretion of platelet-activating factor acetylhydrolase following phorbol ester-stimulated differentiation of HL-60 cells.

Abstract：

:Platelet-activating factor (PAF) plays an important role in a number of biological processes ranging from inflammation to reproductive biology. We have reported that the enzyme that inactivates this potent autacoid, PAF-acetylhydrolase (PAF-AH), is decreased in maternal plasma during the latter stages of pregnancy. This enzyme is associated with the plasma lipoprotein fraction and therefore its tissue origin was thought to be the liver. Prescott and colleagues (J. Biol. Chem. 265, 17381, 1990) have reported that both a rat liver cell line (HepG2 cells) and human peripheral macrophages secrete PAF-AH of the plasma type. We have shown previously that the injection of rats with dexamethasone or medroxyprogesterone causes an increase and estrogen a decrease in the plasma PAF-AH activity. To clarify the mechanism of hormonal regulation of PAF-AH production, we employed a monocyte-macrophage model system to investigate the secretion of PAF-AH during differentiation. In the present study, we have demonstrated that a myelocytic leukemic cell line (HL-60) produces and secretes PAF-AH into a defined medium when the cells are differentiated into macrophages following stimulation by 12-O-tetradecanoylphorbol-13-acetate (TPA). The medium obtained from unstimulated HL-60 cells did not contain detectable amounts of PAF-AH activity. Stimulation with TPA caused a dose- and time-dependent increase in PAF-AH activity in the media. No increase in cell number was observed in the HL-60 cells during the culture period after the cells were treated with TPA. Cell lysis was excluded by the demonstration that the TPA-induced adherent cells excluded trypan blue and did not release lactate dehydrogenase activity into the medium. The increase in PAF-AH activity was inhibited by actinomycin D and cycloheximide. Dexamethasone and medroxyprogesterone markedly increased the secretion of PAF-AH by these cells, while estrogen was without effect. Bacterial endotoxin (lipopolysaccharide, LPS) inhibited the production of PAF-AH by these cells in a dose-dependent manner. The stimulation of PAF-AH secretion during differentiation of HL-60 cells and its modulation by LPS and steroid hormones may provide a useful model system for studying PAF metabolism during the inflammatory response and pregnancy.

journal_name

Arch Biochem Biophys

journal_title

Archives of biochemistry and biophysics

authors

Narahara H,Frenkel RA,Johnston JM

doi

10.1006/abbi.1993.1144

subject

Has Abstract

pub_date

1993-03-01 00:00:00

pages

275-81

issue

eissn

0003-9861

issn

1096-0384

pii

S0003-9861(83)71144-6

journal_volume

301

pub_type

杂志文章

在线工具

Secretion of platelet-activating factor acetylhydrolase following phorbol ester-stimulated differentiation of HL-60 cells.