Integrin alpha v beta 3 and phospholipase C regulate prostacyclin formation of endothelial cells caused by ancrod-generated fibrin.
Ancrod-generated fibrin has been shown to stimulate prostacyclin synthesis of human umbilical vein endothelial cells (Chang et al., 1994, Biochem. Biophys. Res. Commun. 203, 1920). We further investigated its mechanism of action. The increment of 6-keto prostaglandin F1 alpha stimulated by ancrod-generated fibrin was almost completely inhibited when endothelial cells were either pretreated with 50 microM 8-(N,N'-diethylamino)octyl-3,4,5- trimethoxybenzoate (TMB-8) or preloaded with 15 microM 1,2-bis(2- aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). 6-Keto prostaglandin F1 alpha production during 2 and 10 h incubation period was also inhibited by 1.2 mM ethyleneglycol-bis-(beta-aminoethylether)-N,N,N',N'-tetraace tic acid (EGTA) (41 +/- 12 and 53 +/- 17% inhibition, respectively). Further, ancrod-generated fibrin caused a rapid-onset increase in [3h]inositol monophosphate (IP1) formation in endothelial cells. This increase in IP1 was significantly inhibited by 1 mM Gly-Pro-Arg-Pro, 1 mM neomycin or 100 ng/ml pertussis toxin. At the same time, neomycin and pertussis toxin also significantly inhibited 6-keto prostaglandin F1 alpha synthesis of endothelial cells stimulated by ancrod-generated fibrin. Additionally, the increment of IP1 production as well as prostacyclin production were significantly inhibited by monoclonal antibodies directed against alpha v beta 3. These results suggest that intra- and extra-cellular Ca2+ participate in prostacyclin synthesis stimulated by ancrod-generated fibrin. Ancrod-generated fibrin stimulates pertussis toxin-sensitive G-protein regulated phosphoinositide breakdown, which is responsible for prostacyclin synthesis. This augmentation in prostacyclin synthesis and phosphoinositide breakdown caused by ancrod-generated fibrin area, at least in part, mediated by fibrin binding to integrin alpha v beta 3 on endothelial cells.
Chang
M C
MC
Pharmacological Institute, National Taiwan University, Taipei.
Yang
R S
RS
Lin
C H
CH
Huang
T F
TF
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000595:Amino Acid Sequence; D000721:Ancrod / Q000494:pharmacology*; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011464:Epoprostenol / Q000096:biosynthesis*; D005337:Fibrin / Q000096:biosynthesis* / Q000494:pharmacology*; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D007295:Inositol Phosphates / Q000096:biosynthesis; D039201:Integrin alpha3beta1; D016023:Integrins / Q000502:physiology*; D008969:Molecular Sequence Data; D009355:Neomycin / Q000494:pharmacology; D037342:Pertussis Toxin; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D010738:Type C Phospholipases / Q000502:physiology*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D002121:Calcium Channel Blockers; D003470:Culture Media; D005343:Fibrinolytic Agents; D007295:Inositol Phosphates; D039201:Integrin alpha3beta1; D016023:Integrins; D011500:Protein Synthesis Inhibitors; D010566:Virulence Factors, Bordetella; D004533:Egtazic Acid; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D015121:6-Ketoprostaglandin F1 alpha; D005707:Gallic Acid; D005337:Fibrin; D011464:Epoprostenol; D037342:Pertussis Toxin; D010738:Type C Phospholipases; D000721:Ancrod; D009355:Neomycin; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid