The Protective Of Dexmedetomidine On Liver Injury In Mice Its Mechanism

Objective: To observe the effect of dexmedetomidine on liver injury model mice induced by two factors,this paper discusses the protective effect of dexmedetomidine on liver injury in mice,and tries to clarify its possible mechanism.Methods: In the first part,the mouse model of cholestatic hepatic fibrosis was established by bile duct ligation(BDL).Forty C57/BL6 mice were randomly divided into four groups.They were divided into Control group(CON group,sham operation+intraperitoneal injection of the same amount of normal saline),Model group(MOD group,bdl+ intraperitoneal injection of the same amount of normal saline),Positive control group(PC group,bdl + intraperitoneal injection of colchicine 0.2mg/kg),Dexmedetomidine control group(DEX group,bdl + intraperitoneal injection of dexmedetomidine 10μg/kg).The CON group only open the abdominal cavity without ligation.Fasting can not help water for 12 hours.The mice were killed after anesthesia.The serum of mice was collected and the contents of serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)were measured by microplate method.ELISA was used to detect type Ⅲ procollagen(PC-Ⅲ),type Ⅳcollagen(Ⅳ-C)in mouse serum and tumor necrosis factor in liver tissue-ɑ(Tumor Necrosis Factor-ɑ,TNF-ɑ)、 Interleukin-6(IL-6),interleukin-1β(IL-1β).The activities of superoxide dismutase(SOD),malondialdehyde(MDA),glutathione(GSH)and glutathione peroxidase(GSH PX)in mouse liver were measured.He,Masson and Sirius red staining were performed to observe the pathological changes of liver tissue.Western blot was used to detect the expression level of phosphatidylinositol 3-kinases(PI3K),protein kinase B(AKT),nuclear factor E2(Nrf2),heme oxygenase-1(HO-1)and nuclear transcription factor in mouse liver-κB(Nuclear factor kappa-B,NF-κB)、TNF-ɑ、IL-6 protein factor.In the second part,the mouse model of drug-induced liver injury was induced by acetaminophen(APAP).Forty C57/BL6 mice were randomly divided into four groups with 10 mice in each group.They were divided into normal control group(CON group,intraperitoneal injection of the same amount of normal saline),model group(MOD group,intraperitoneal injection of APAP 200mg/kg),positive control group(PC group,intraperitoneal injection of APAP 200mg/kg and colchicine 0.2mg/kg)and dexmedetomidine group(DEX group,intraperitoneal injection of APAP200mg/kg and dexmedetomidine 10μg/kg).Fasting can not help water for 12 hours.The mice were killed after anesthesia.The serum of mice was collected and the contents of ALT and AST were measured.The activities of SOD,MDA,GSH and GSH-PX in mouse liver were measured.The level of TNF-α、IL-6、IL-1β were detected by ELISA.HE staining was used to observe the pathological changes of liver tissue.Western blot was used to detect the expression level of PI3K、Akt、Nrf2、HO-1、NF-κB、TNF-ɑ、IL-6.Results:1、BDL model,compared with MOD group,the organ index,the levels of ALT and AST in serum,the contents of pc-Ⅲ and IV-C,GSH and MDA in mod group increased significantly(P<0.05),the activities of SOD and GSH-PX decreased(P<0.05),the level of TNF-α、IL-6、IL-1β increased significantly(P<0.05).Compared with MOD group,the organ index,the level of ALT and AST in serum,the contents of pc-Ⅲ and IV-C,GSH and MDA in mod group decreased significantly(P<0.05),the activities of SOD and GSH-PX increased(P<0.05),the level of TNF-α、IL-6 、 IL-1β decreased significantly(P<0.05).HE staining showed that the morphological structure of liver tissue was normal in CON group,hepatocyte edema,inflammatory infiltration and focal necrosis in MOD group,and cell edema was reduced in DEX group,with only a small amount of inflammatory cell infiltration.Masson staining showed that the liver tissue fibers increased in mod group and decreased in DEX group.Sirius red staining showed that liver tissue fibers increased in mod group and decreased in DEX group.Western blot showed that compared with con group,the expression level of PI3K/Akt protein in mod group increased(P<0.05),the expression level of Nrf2/HO-1 protein decreased(P <0.05),the expression level of p65、IKB α、TNF-α、IL-6 protein increased(P<0.05).Compared with MOD group,DEX group decreased the expression level of PI3K/Akt protein in liver tissue of model mice(P<0.05),increased the expression level of Nrf2/HO-1(P<0.05),the expression level of p65、IKB α、TNF-α、IL-6 decreased(P<0.05).2、APAP model,compared with con group,the serum levels of ALT and AST in mod group increased(P<0.05),the levels of GSH and MDA increased(P<0.05),the activities of SOD and GSH-PX decreased(P<0.05),the level of TNF-α、IL-6、IL-1βincreased significantly(P<0.05).Compared with MOD group,the serum ALT and AST level in DEX group decreased(P<0.05),the contents of SOD and GSH-PX increased(P<0.05),the contents of GSH and MDA decreased(P<0.05),the level of TNF-α、IL-6、IL-1β significantly decreased(P<0.05).HE staining showed that the morphological structure of liver tissue was normal in CON group,hepatocyte edema,inflammatory infiltration and focal necrosis in MOD group,and cell edema was reduced in DEX group,with only a small amount of inflammatory cell infiltration.Western blot showed that compared with CON group,the expression level of PI3K/Akt protein in MOD group increased(P<0.05),the expression level of Nrf2/HO-1 protein decreased(P<0.05),the expression level of p65、IKBα、TNF-α、IL-6 protein increased(P<0.05).Compared with MOD group,DEX group decreased the expression level of PI3K/Akt protein in liver tissue of model mice(P<0.05)and increased the expression level of Nrf2/HO-1 protein(P<0.05).DEX group decreased the level of p65、IKBα、TNF-α、IL-6 protein(P<0.05).Conclusion:1 、 Dexmedetomidine can improve the liver function of hepatic fibrosis in cholestatic mice and liver injury in APAP induced drug-induced mice.2、The protective mechanism of dexmedetomidine on liver injury model mice caused by two factors be related,which may be reducing the level of oxidative stress and the production of inflammatory factors.Dexmedetomidine demonstrated a protective effect on liver damage potentially via activation of the PI3K/Akt/Nrf2 and NF-κB/IKBα/TNF-α signaling pathway.