Modulation of superoxide generation in in vivo lipopolysaccharide-primed Kupffer cells by staurosporine, okadaic acid, manoalide, arachidonic acid, genistein and sodium orthovanadate

J Pharmacol Exp Ther. 1994 Jan;268(1):238-47.

Abstract

Continuous infusion of a nonlethal dose of Escherichia coli lipopolysaccharide (LPS) into rats induced extravasation of mononuclear phagocytes into the liver and the priming of Kupffer cells for in vitro phorbol myristate acetate (PMA)-stimulated superoxide anion (O2-) release. The purpose of this investigation was to determine the role of protein kinase C (PKC), protein serine-threonine phosphatase(s) 1 and 2a, protein tyrosine kinase(s) and phosphatase(s), phospholipase A2 (PLA2), arachidonic acid (AA) and its cyclooxygenase (CO) and 5-lipoxygenase (5-LO) metabolites in the modulation of PMA-stimulated O2-generation in in vivo LPS-primed rat Kupffer cells. The following inhibitors blocked PMA-stimulated O2- generation in the absence (-AA) or presence of AA (+AA) (50 microM): 1) staurosporine, a putative PKC inhibitor (150 nM, 95% inhibition without AA, 88% inhibition with AA); 2) okadaic acid, a protein serine-threonine phosphatase inhibitor (2 microM, 65% inhibition with or without AA); 3) the marine PLA2 inhibitor manoalide (1 microM, 97.5% inhibition without AA, 75% with AA). In addition, it was observed that exogenously added AA enhanced PMA-stimulated O2- generation in a time- and dose-dependent manner (5-50 microM) and partially reversed the inhibitory effect of manoalide. The following inhibitors did not block PMA-stimulated O2- generation in the absence or presence of AA: 1) indomethacin, a CO inhibitor (1-100 microM) and WY-50,295M tromethamine, a novel 5-LO inhibitor (1-100 microM); 2) genistein, a protein tyrosine kinase inhibitor (1-100 microM); and 3) sodium orthovanadate (1-300 microM), a protein tyrosine phosphatase inhibitor. It was concluded that, in in vivo LPS-primed Kupffer cells, PMA-stimulated O2- generation is modulated by PKC, protein serine-threonine phosphatase(s), PLA2 and AA but not by protein tyrosine kinase(s) and phosphatase(s) and CO and 5-LO products. These findings could have implications on the design of novel therapeutic approaches for the modulation of enhanced O2- release by Kupffer cells in endotoxemia.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alkaloids / pharmacology
  • Animals
  • Arachidonate 5-Lipoxygenase / metabolism
  • Arachidonic Acid / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Ethers, Cyclic / pharmacology
  • Genistein
  • In Vitro Techniques
  • Isoflavones / pharmacology
  • Kupffer Cells / drug effects*
  • Kupffer Cells / enzymology*
  • Lipopolysaccharides / pharmacology*
  • Male
  • Okadaic Acid
  • Phospholipases A / metabolism
  • Phospholipases A2
  • Phosphoprotein Phosphatases / metabolism
  • Prostaglandin-Endoperoxide Synthases / metabolism
  • Protein Kinase C / metabolism
  • Protein Tyrosine Phosphatases / metabolism
  • Protein-Tyrosine Kinases / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Staurosporine
  • Superoxides / metabolism*
  • Terpenes / pharmacology
  • Tetradecanoylphorbol Acetate / pharmacology
  • Vanadates / pharmacology

Substances

  • Alkaloids
  • Enzyme Inhibitors
  • Ethers, Cyclic
  • Isoflavones
  • Lipopolysaccharides
  • Terpenes
  • Superoxides
  • Okadaic Acid
  • Arachidonic Acid
  • Vanadates
  • Genistein
  • manoalide
  • Arachidonate 5-Lipoxygenase
  • Prostaglandin-Endoperoxide Synthases
  • Protein-Tyrosine Kinases
  • Protein Kinase C
  • Phospholipases A
  • Phospholipases A2
  • Phosphoprotein Phosphatases
  • Protein Tyrosine Phosphatases
  • Staurosporine
  • Tetradecanoylphorbol Acetate