CD14-dependent mechanism for endotoxin-mediated nitric oxide synthesis in murine macrophages.

Journal Article (Journal Article)

Endotoxin-mediated macrophage synthesis of nitric oxide (NO) is associated with immune effector function, intercellular communication, leukocyte adhesion, vascular integrity, and neurotransmission. However, little is known of the cellular receptor and signal transduction pathway by which endotoxin induces NO production. With the use of a model of ANA-1 murine macrophages, we stimulated NO production by incubation with increasing concentrations of endotoxin and 5% fetal calf serum. In selected instances, the anti-CD14 antibody, ED9, was added. Endotoxin-mediated NO synthesis was dependent on CD14 function and the presence of an additional serum factor. Endotoxin treatment increased plasma membrane GTPase activity and 35S-labeled guanosine 5'-O-(3-thiotriphosphate) ([35S]GTP gamma S) binding. Conversely, coincubation of cells with endotoxin and the heterotrimeric G protein inhibitors, suramin and guanosine 5'-O-(2-thiodiphosphate) trilithium salt, was associated with decreased NO synthesis, plasma membrane GTPase activity, and [35S]GTP gamma S binding. Blockade of CD14 or G protein function was associated with ablation of endotoxin-mediated inducible NO synthase (iNOS) protein expression, iNOS mRNA levels, and iNOS gene transcription, as determined by immunoblot, reverse transcriptase-polymerase chain reaction, and nuclear run-on analyses, respectively. These results indicate that endotoxin-mediated NO synthesis is a CD14-heterotrimeric G protein-dependent process.

Full Text

Duke Authors

Cited Authors

  • Schroeder, RA; delaTorre, A; Kuo, PC

Published Date

  • September 1997

Published In

Volume / Issue

  • 273 / 3 Pt 1

Start / End Page

  • C1030 - C1039

PubMed ID

  • 9316424

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajpcell.1997.273.3.C1030


  • eng

Conference Location

  • United States