2-Benzyloxybenzaldehyde inhibits formyl-methionyl-leucyl-phenylalanine stimulation of phospholipase D activation in rat neutrophils.
2-Benzyloxybenzaldehyde (CCY1a) inhibited the formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated phospholipase D (PLD)-mediated products, phosphatidic acid (PA) and phosphatidylethanol (PEt) formation in rat neutrophils in a concentration-dependent manner with IC(50) values of 15.8+/-2.5 and 13.9+/-2.0 microM, respectively. The underlying cellular signaling mechanism of CCY1a inhibition was investigated. CCY1a inhibited the plateau phase but not the initial Ca(2+) spike of fMLP-stimulated Ca(2+) signal. CCY1a did not inhibit the [Ca(2+)](i) change in Ca(2+)-free medium in response to fMLP, but inhibited the [Ca(2+)](i) change by the subsequent addition of Ca(2+). In addition, CCY1a treatment attenuated the fMLP-induced protein tyrosine phosphorylation. The membrane translocation of ADP-ribosylation factor (ARF) and Rho A proteins in neutrophils stimulated with fMLP was attenuated by CCY1a in a concentration-dependent manner. In a cell-free system, neither the membrane association of ARF and Rho A caused by GTPgammaS nor the phorbol myristate acetate-stimulated membrane translocation of Rho A was suppressed significantly by CCY1a. These results indicate that the attenuation of protein tyrosine phosphorylation, blockade of Ca(2+) entry, and the suppression of ARF and Rho A membrane translocation are probably obligatory for the CCY1a inhibition of PLD activity in rat neutrophils in response to fMLP.
Wang
Jih-Pyang
JP
Department of Education and Research, Taichung Veterans General Hospital, 160, Chung Kang Road, Sec. 3, Taiwan, ROC. w1994@vghtc.vghtc.gov.tw
Chang
Ling-Chu
LC
Hsu
Mei-Feng
MF
Huang
Li-Jiau
LJ
Kuo
Sheng-Chu
SC
D020727:ADP-Ribosylation Factors / Q000378:metabolism; D000818:Animals; D001547:Benzaldehydes / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D020404:Glycerophospholipids / Q000378:metabolism; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010712:Phosphatidic Acids / Q000378:metabolism; D010739:Phospholipase D / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
C468728:2-benzyloxybenzaldehyde; D001547:Benzaldehydes; D004791:Enzyme Inhibitors; D020404:Glycerophospholipids; D010712:Phosphatidic Acids; C051521:phosphatidylethanol; D009240:N-Formylmethionine Leucyl-Phenylalanine; D010739:Phospholipase D; D020727:ADP-Ribosylation Factors; D020742:rhoA GTP-Binding Protein; D002118:Calcium