Connexin-43-dependent ATP release mediates macrophage activation during sepsis

Elife. 2019 Feb 8;8:e42670. doi: 10.7554/eLife.42670.

Abstract

Bacterial spillage into a sterile environment following intestinal hollow-organ perforation leads to peritonitis and fulminant sepsis. Outcome of sepsis critically depends on macrophage activation by extracellular ATP-release and associated autocrine signalling via purinergic receptors. ATP-release mechanisms, however, are poorly understood. Here, we show that TLR-2 and -4 agonists trigger ATP-release via Connexin-43 hemichannels in macrophages leading to poor sepsis survival. In humans, Connexin-43 was upregulated on macrophages isolated from the peritoneal cavity in patients with peritonitis but not in healthy controls. Using a murine peritonitis/sepsis model, we identified increased Connexin-43 expression in peritoneal and hepatic macrophages. Conditional Lyz2cre/creGja1flox/flox mice were developed to specifically assess Connexin-43 impact in macrophages. Both macrophage-specific Connexin-43 deletion and pharmacological Connexin-43 blockade were associated with reduced cytokine secretion by macrophages in response to LPS and CLP, ultimately resulting in increased survival. In conclusion, inhibition of autocrine Connexin-43-dependent ATP signalling on macrophages improves sepsis outcome.

Keywords: ATP release; Connexin-43; human; immunology; infectious disease; inflammation; macrophages; microbiology; mouse; purinergic signaling; sepsis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / genetics
  • Animals
  • Autocrine Communication / genetics
  • Connexin 43 / antagonists & inhibitors
  • Connexin 43 / genetics*
  • Disease Models, Animal
  • Gene Expression Regulation / genetics
  • HEK293 Cells
  • Humans
  • Lipopolysaccharides / toxicity
  • Liver / metabolism
  • Liver / microbiology
  • Liver / pathology
  • Macrophage Activation / drug effects
  • Macrophage Activation / genetics
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Macrophages / microbiology
  • Macrophages / pathology
  • Mice
  • Peritoneal Cavity / microbiology
  • Peritoneal Cavity / pathology
  • Peritonitis / drug therapy
  • Peritonitis / genetics
  • Peritonitis / microbiology
  • Peritonitis / pathology
  • Probenecid / pharmacology
  • Sepsis / chemically induced
  • Sepsis / genetics*
  • Sepsis / microbiology
  • Sepsis / pathology
  • Toll-Like Receptor 2 / genetics
  • Toll-Like Receptor 4 / genetics

Substances

  • Connexin 43
  • GJA1 protein, mouse
  • Lipopolysaccharides
  • Tlr2 protein, mouse
  • Tlr4 protein, mouse
  • Toll-Like Receptor 2
  • Toll-Like Receptor 4
  • Adenosine Triphosphate
  • Probenecid