Selective α7-nicotinic acetylcholine receptor agonist GTS-21 improves survival in murine endotoxemia and severe sepsis*

Abstract

OBJECTIVE: Tumor necrosis factor and high mobility group box 1 are critical cytokine mediators of inflammation. The efferent vagus nerve inhibits cytokine release through alpha7-nicotinic acetylcholine receptor-mediated cholinergic signaling. Here we studied whether GTS-21, a selective alpha7-nicotinic acetylcholine receptor agonist, inhibits proinflammatory cytokines in vitro and in vivo and improves survival in murine endotoxemia and severe sepsis. DESIGN: Randomized and controlled in vitro and in vivo study. SETTINGS: Research laboratory and animal facility rooms. SUBJECTS: RAW 264.7 cells and BALB/c mice treated with endotoxin or subjected to cecal ligation and puncture (CLP). INTERVENTIONS: RAW 264.7 cells were exposed to endotoxin (4 ng/mL or 10 ng/mL) in the presence or absence of GTS-21 (1-100 muM), and tumor necrosis factor and high mobility group box 1 release and nuclear factor-kappaB activation were analyzed. Mice were treated with GTS-21 (0.4 mg/kg or 4 mg/kg, intraperitoneally) or saline 30 mins before endotoxin (6 mg/kg, intraperitoneally), and serum tumor necrosis factor was analyzed 1.5 hrs after the onset of endotoxemia. In survival experiments, mice were treated with GTS-21 (0.4 or 4.0 mg/kg, intraperitoneally) or saline 30 mins before and 6 hrs after endotoxin and then twice daily for 3 days. Severe sepsis was induced by CLP. Mice were treated with GTS-21 (4 mg/kg) or saline immediately and 6 hrs and 24 hrs after CLP, and serum high mobility group box 1 was analyzed 30 hrs after CLP. In survival experiments, GTS-21 (0.4 or 4 mg/kg) treatment was initiated 24 hrs after CLP and continued twice daily for 3 days. MEASUREMENTS AND MAIN RESULTS: GTS-21 dose-dependently inhibited tumor necrosis factor and high mobility group box 1 release and nuclear factor-kappaB activation in vitro. GTS-21 (4 mg/kg) significantly inhibited serum tumor necrosis factor during endotoxemia and improved survival (p < .0001). GTS-21 (4 mg/kg) significantly inhibited serum high mobility group box 1 levels in CLP mice and improved survival (p < .0006). CONCLUSION: These findings are of interest for the development of alpha7-nicotinic acetylcholine receptor agonists as a new class of anti-inflammatory therapeutics.