Artocarpol A stimulation of superoxide anion generation in neutrophils involved the activation of PLC, PKC and p38 mitogen-activated PK signaling pathways.
1 Artocarpol A (ART), a natural phenolic compound isolated from Artocarpus rigida, stimulated a slow onset and long-lasting superoxide anion generation in rat neutrophils, whereas only slightly activated the NADPH oxidase in a cell-free system. 2 Pretreatment of neutrophils with pertussis toxin (1 microg ml(-1)), 50 microM 2'-amino-3'-methoxyflavone (PD 98059), or 1 microM 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene (U0126) had no effect on ART-stimulated superoxide anion generation. ART (30 microM) did not induce extracellular signal-regulated kinase (ERK) phosphorylation. 3 4-(4-Fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole (SB 203580) markedly attenuated the ART-stimulated superoxide anion generation (IC50 value of 4.3+/-0.3 microM). Moreover, ART induced p38 mitogen-activated PK (MAPK) phosphorylation and activation. 4 The superoxide anion generation in response to ART was also substantially inhibited in a Ca2+-free medium, and by pretreatment with 1 microM 1-[6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl]-1H-pyrrole-2,5-dione (U-73122) and 100 microM 2-aminoethyldiphenyl borate (2-APB). ART (30 microM) stimulated the [Ca2+]i elevation in the presence or absence of external Ca2+, and also increased the D-myo-inositol 1,4,5-trisphosphate formation. 5 2-[1-(3-Dimethylaminopropyl)-1H-indol-3-yl]-3-(1H-indol-3-yl)-maleimide (GF 109203X) greatly inhibited the ART-stimulated superoxide anion generation (IC50 value of 7.8+/-1.0 nM). ART increased the recruitment of PKC-alpha, -betaI, and -betaII to the plasma membrane of neutrophils, and stimulated Ca2+-dependent PKC activation in the cytosol preparation. 6 ART induced the phosphorylation of p47phox, which was attenuated by GF 109203X. Moreover, ART evoked the membrane association of p47(phox), which was inhibited by GF 109203X and SB 203580. 7 These results indicate that the ART stimulation of superoxide anion generation involved the activation of p38 MAPK, PLC/Ca2+, and PKC signaling pathways in rat neutrophils.
Kuan
Yu-Hsiang
YH
Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China.
Lin
Ruey-Hseng
RH
Tsao
Lo-Ti
LT
Lin
Chun-Nan
CN
Wang
Jih-Pyang
JP
D000818:Animals; D002070:Butadienes / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002474:Cell-Free System / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology; D015151:Immunoblotting; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D010738:Type C Phospholipases / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
D002070:Butadienes; D004791:Enzyme Inhibitors; D004963:Estrenes; D005419:Flavonoids; D006576:Heterocyclic Compounds, 4 or More Rings; D007093:Imidazoles; D007211:Indoles; D008301:Maleimides; D009570:Nitriles; D011725:Pyridines; D011760:Pyrrolidinones; C113580:U 0126; C492477:artocarpol A; D013481:Superoxides; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D009240:N-Formylmethionine Leucyl-Phenylalanine; D011493:Protein Kinase C; D048051:p38 Mitogen-Activated Protein Kinases; D010738:Type C Phospholipases; C070515:bisindolylmaleimide I; D013755:Tetradecanoylphorbol Acetate; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D002118:Calcium