Dexmedetomidine attenuates lipopolysaccharide-induced liver oxidative stress and cell apoptosis in rats by increasing GSK-3 beta/MKP-1/Nrf2 pathway activity via the alpha 2 adrenergic receptor

摘要

Dexmedetomidine (DEX) protects against liver damage caused by sepsis. The purpose of this study was to confirm the regulatory effects of DEX on glycogen synthase kinase 3 beta (GSK-3 beta) via the alpha 2 adrenergic receptor (alpha 2AR) and evaluate the role of GSK-3 beta in lipopolysaccharide (LPS)-induced iver injury. Sprague-Dawley (SD) rats were administered an intraperitoneal injection of DEX (30 mu g/kg) 30 min before an intraperitoneal injection of LPS (10 mg/kg). HE staining and serum biochemical test results indicated that DEX significantly improved liver histopathological damage and liver function indices. Furthermore, DEX increased super oxide dismutase (SOD) activity and L-glutathione (GSH) levels, and inhibited malondialdehyde (MDA) production. Western blot (WB) analysis demonstrated that treatment with the GSK-3 beta inhibitor SB216763 increased antioxidant-related protein mitogen-activated protein kinase phosphatase 1 (MKP-1) and nuclear factor erythroid 2 related factor 2 (Nrf2) expression. in addition, anti-apoptosis-related proteins were up-regulated and pro-apoptosis-related proteins were down-regulated by SB21676 administration. WB analysis also showed that DEX increased anti-apoptosis-related protein levels and decreased pro-apoptotic protein levels in LPS-induced liver injury. Nrf2, p53, and activated caspase-3 levels were further evaluated using immunohistochemistry (IHC), producing results consistent with WB results. The alpha 2AR antagonist atipamezole (AT) significantly reversed the protective effects of DEX, as shown by WB analysis. Our data suggested that alpha 2AR plays an important role in reversing the effects of liver oxidative stress and apoptosis via DEX, and that DEX exerts antioxidant and antiapoptosis effects through regulation of the GSK-3 beta/MKP-1/Nrf2 pathway.