Dexmedetomidine inhibits LPS-induced proinflammatory responses via suppressing HIF1α-dependent glycolysis in macrophages

Abstract

Dexmedetomidine, a highly selective alpha 2-adrenoceptor agonist, has been reported to exert an anti-inflammatory effect in several animal models, but the mechanism remains unclear. Previous studies have shown that hypoxia inducible factor 1 alpha-induced glycolysis is essential for the activation of inflammatory macrophages. However, whether dexmedetomidine influences hypoxia inducible factor 1 alpha-induced glycolysis and thus exerts an anti-inflammatory effect has been poorly investigated. This study aims to elucidate the anti-inflammatory mechanism of dexmedetomidine involving the hypoxia inducible factor 1 alpha-dependent glycolytic pathway. We showed that dexmedetomidine could suppress lipopolysaccharide-induced inflammatory cytokine production; inhibit the extracellular acidification rate, glucose consumption and lactate production; and decrease the expression of glycolytic genes in macrophages. The enhancement of glycolysis by the granulocyte-macrophage colony-stimulating factor or higher concentration of glucose could reverse the anti-inflammatory effect of dexmedetomidine on lipopolysaccharide-treated macrophages. Moreover, dexmedetomidine significantly inhibited the upregulation of hypoxia inducible factor 1 alpha at the mRNA and protein levels. Genetic inhibition of hypoxia inducible factor 1 alpha expression could reverse the anti-inflammatory effect of dexmedetomidine. Taken together, our results indicate that dexmedetomidine attenuates lipopolysaccharide-induced proinflammatory responses partially by suppressing hypoxia inducible factor 1 alpha-dependent glycolysis in macrophages.