Nuclear factor-kappaB mediates simultaneous induction of inducible nitric-oxide synthase and Up-regulation of the cationic amino acid transporter CAT-2B in rat alveolar macrophages

Mol Pharmacol. 2000 Dec;58(6):1294-302.

Abstract

The connection between the regulation of L-arginine transport and nitric oxide (NO) synthesis was studied in rat alveolar macrophages. Lipopolysaccharides (LPSs) and interferon-gamma stimulated in the same concentration- and time-dependent manner NO synthesis (measured by nitrite accumulation) and L-[(3)H]arginine uptake. This correlated with an increased mRNA expression for iNOS and the cationic amino acid transporter CAT-2B (analyzed by reverse transcription-polymerase chain reaction), with the same kinetics observed for the up-regulation of both mRNAs. Because nuclear factor-kappaB (NF-kappaB) is essential for induction of iNOS its role for the regulation of CAT-2B expression and L-arginine transport was investigated. The NF-kappaB inhibitors pyrrolidine dithiocarbamate and N(alpha)-p-tosyl-L-lysine chloromethyl ketone abrogated LPS- and interferon-gamma-induced increase of nitrite accumulation and L-[(3)H]arginine uptake as well as up-regulation of iNOS and CAT-2B mRNA. LPS-induced increase in iNOS and CAT-2B mRNA was also suppressed by specific NF-kappaB decoy oligodesoxynucleotides, confirming the essential role of NF-kappaB for iNOS and CAT-2B expression. Dexamethasone did not affect the initial (5 h) LPS-induced increase of iNOS and CAT-2B mRNA, but down-regulated both mRNAs after prolonged (20 h) exposure and this was accompanied by partial inhibition of LPS-stimulated nitrite accumulation and L-[(3)H]arginine uptake. These findings demonstrate parallel regulation of the expression of iNOS and CAT-2B, and of NO synthesis and L-arginine uptake in rat alveolar macrophages. NF-kappaB is an essential transcription factor not only for the induction of iNOS, but also for the up-regulation of CAT-2B. The simultaneous up-regulation of CAT-2B with iNOS is considered as a mechanism to ensure a high substrate supply for iNOS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems, Basic
  • Animals
  • Arginine / metabolism
  • Carrier Proteins / genetics*
  • Cells, Cultured
  • Cycloheximide / pharmacology
  • Dexamethasone / pharmacology
  • Drug Interactions
  • Enzyme Induction
  • Female
  • GPI-Linked Proteins
  • Gene Expression Regulation
  • Interferon-gamma / pharmacology
  • Lipopolysaccharides / pharmacology
  • Macrophages, Alveolar / enzymology
  • Macrophages, Alveolar / physiology*
  • Male
  • Membrane Proteins / genetics*
  • NF-kappa B / antagonists & inhibitors
  • NF-kappa B / physiology*
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase / biosynthesis*
  • Nitric Oxide Synthase / genetics
  • Nitric Oxide Synthase Type II
  • Protein Synthesis Inhibitors / pharmacology
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Tumor Necrosis Factor / metabolism
  • Receptors, Tumor Necrosis Factor, Member 10c
  • Signal Transduction / drug effects
  • Tumor Necrosis Factor Decoy Receptors
  • Up-Regulation

Substances

  • Amino Acid Transport Systems, Basic
  • Carrier Proteins
  • GPI-Linked Proteins
  • Lipopolysaccharides
  • Membrane Proteins
  • NF-kappa B
  • Protein Synthesis Inhibitors
  • RNA, Messenger
  • Receptors, Tumor Necrosis Factor
  • Receptors, Tumor Necrosis Factor, Member 10c
  • TNFRSF10C protein, human
  • Tumor Necrosis Factor Decoy Receptors
  • Nitric Oxide
  • Dexamethasone
  • Interferon-gamma
  • Arginine
  • Cycloheximide
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type II
  • Nos2 protein, rat