Related Experiment Video

Updated: Aug 12, 2026

HPLC-based Assay to Monitor Extracellular Nucleotide/Nucleoside Metabolism in Human Chronic Lymphocytic Leukemia Cells
11:29

HPLC-based Assay to Monitor Extracellular Nucleotide/Nucleoside Metabolism in Human Chronic Lymphocytic Leukemia Cells

Published on: July 20, 2016

Regulation of arachidonic acid mobilization in lipopolysaccharide-activated P388D(1) macrophages by adenosine

M A Balboa1, J Balsinde, C A Johnson

  • 1Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California 92093-0601, USA.

The Journal of Biological Chemistry
|December 14, 1999
PubMed

Insights

Bacterial lipopolysaccharide (LPS) triggers delayed prostaglandin synthesis in macrophages via P2X7 receptors. Blocking these receptors with antagonists suppresses arachidonic acid release and key enzyme expression, revealing a novel signaling pathway.

Area of Science:

  • Immunology
  • Cell Biology
  • Pharmacology

Background:

  • Macrophages play a crucial role in inflammatory responses.
  • Lipopolysaccharide (LPS) from bacteria is a potent immune activator.
  • Prostaglandin synthesis is a key component of the inflammatory cascade.

Purpose of the Study:

  • To investigate the role of P2X7 purinergic receptors in LPS-induced prostaglandin biosynthesis in P388D(1) macrophages.
  • To elucidate the signaling pathways involved in LPS-mediated arachidonic acid mobilization.

Main Methods:

  • Treatment of P388D(1) macrophages with LPS.
  • Application of P2X7 receptor antagonists (periodate-oxidized ATP and pyridoxal-phosphate-6-azophenyl-2', 4'-disulfonic acid).
  • Measurement of arachidonic acid metabolite release and expression of Group V secretory phospholipase A(2) and cyclooxygenase-2.

Main Results:

  • P2X7 receptor antagonists significantly attenuated LPS-induced arachidonic acid metabolite release.
  • Antagonist treatment suppressed the expression of Group V secretory phospholipase A(2) and cyclooxygenase-2.
  • The observed effects were specific to LPS stimulation, not affecting responses to platelet-activating factor or Ca(2+) ionophore.

Conclusions:

  • The P2X7 purinergic receptor is coupled to the arachidonic acid cascade in P388D(1) macrophages.
  • P2X7 receptor activation is implicated in LPS-induced arachidonic acid mobilization and subsequent prostaglandin synthesis.

More Related Videos

A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces07:55

A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces

Published on: January 7, 2020

Measuring the Rate of Lipolysis in Ex Vivo Murine Adipose Tissue and Primary Preadipocytes Differentiated In Vitro09:41

Measuring the Rate of Lipolysis in Ex Vivo Murine Adipose Tissue and Primary Preadipocytes Differentiated In Vitro

Published on: March 17, 2023

Related Concept Videos

Phosphoinositides and PIPs01:42

Phosphoinositides and PIPs

Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs.
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
GPCRs Regulate Adenylyl Cylase Activity01:09

GPCRs Regulate Adenylyl Cylase Activity

Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
cAMP-dependent Protein Kinase Pathways01:25

cAMP-dependent Protein Kinase Pathways

Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
IP3/DAG Signaling Pathway01:11

IP3/DAG Signaling Pathway

Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the  phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and produces two-second...