The protective effect of PNU-282987, a selective α7 nicotinic acetylcholine receptor agonist, on the hepatic ischemia-reperfusion injury is associated with the inhibition of high-mobility group box 1 protein expression and nuclear factor κB activation in mice

Abstract

Hepatic ischemia-reperfusion (I/R) injury contributes to hepatic dysfunction and failure after liver transplantation, major hepatic resection, trauma, and hypovolemic shock. Therefore, reducing I/R injury is an important goal to improve the outcome of these procedures. Recently, high-mobility group box 1 protein (HMGB1) has been identified as a pathogenic mediator in several inflammatory diseases, including hepatic I/R. PNU-282987, a selective α7 nicotinic acetylcholine receptor agonist, prevents nuclear factor κB (NF-κB) activation and thereby inhibits cytokine secretion through a specific cholinergic anti-inflammatory pathway. Our study was designed to evaluate whether PNU-282987 would inhibit HMGB1 expression and prevent I/R-induced liver damage. C57BL/6 mice were randomly divided into 3 groups as follows: sham group, vehicle plus I/R group, and PNU-282987 plus I/R group. Mice were subjected to 70% partial hepatic I/R for 60 min and pretreated with either vehicle or with PNU-282987, and blood and hepatic tissue samples were collected at 3, 6, and 12 h following reperfusion. The results showed that pretreatment with PNU-282987 decreased serum transaminase levels and ameliorated liver injury after hepatic I/R. Moreover, pretreatment with PNU-282987 suppressed NF-κB activation, cytokine production (tumor necrosis factor α, interleukin 1β), and HMGB1 expression in liver after hepatic I/R. These observations suggest that PNU-282987 protects the liver from I/R injury possibly by inhibiting HMGB1 expression, suppressing cytokine production, and preventing NF-κB activation in mice.