ABSTRACT
Objective ::To investigate the role of trehalose in hepatic ischemia-reperfusion injury and its underlying mechanisms.Methods:C57BL/6J mice were randomly divided into no-ischemia group, ischemia-reperfusion group, trehalose-treated group and normal saline control group. After ischemia for 90 minutes, reperfusion immediately or 6h, blood and liver tissues were collected, and serum was separated. The liver function parameters of ALT, AST, the inflammatory factors of TNF-α, IL-1β and IL-2, and the pathological changes of liver were detected to study the role of trehalose during hepatic ischemia-reperfusion injury. Hypoxia-reoxygenation cell model was established by AML12 mouse hepatocyte line, and divided into experimental group and control group. The experimental group was divided into low dose group and high dose group according to the concentration of trehalose administrated. And the control group had no use of trehalose. The level of apoptosis was measured to study the effect of trehalose on apoptosis induced by hepatic ischemia-reperfusion injury with flow cytometry. Western blot was utilized for detecting the levels of Caspase-3, Cleaved Caspase-3 and Bcl-2 protein to understand the molecular mechanisms of trehalose in apoptosis during hepatic ischemia-reperfusion injury.Results:In vivo animal experiments showed that liver function and such inflammatory factors as ALT, AST, TNF-α, IL-1β and IL-2 increased in ischemia-reperfusion group after hepatic ischemia-reperfusion ( P<0.05), and liver tissue became necrotic. After a treatment of trehalose, the levels of ALT, AST, TNF-α, IL-1β and IL-2 were lower than those of normalsaline control group and the area of liver tissue necrosis also decreased ( P<0.05). In vitro cell experiments showed that the apoptosis level of hepatocytes in the experimental group decreased compared with the control group.And the level of activated pro-apoptotic protein Cleaved Caspase-3 decreased, the level of anti-apoptotic protein Bcl-2 increased. Conclusions:Trehalose has protective effects on hepatic ischemia-reperfusion injury in vivo and in vitro. The mechanism may be involved in inhibiting inflammation induced by hepatic ischemia-reperfusion injury, suppressing the activation of Caspase-3 and promoting the expression of Bcl-2, thus played a protective role by extenuation of hepatocyteapoptosis.
ABSTRACT
Objective To investigate the value of cytokines in bile combined with clinical indices in predicting the degree of liver injury after liver transplantation. MethodsA total of 16 patients undergoing liver transplantation who were hospitalized in Center of Organ Transplantation, The Affiliated Hospital of Qingdao University, from January to December 2018 were enrolled, and according to the level of alanine aminotransferase (ALT) on day 1 after surgery, the patients were divided into mild liver injury (ALT ＜500 U/L) group with 10 patients and severe liver injury (ALT ＞500 U/L) group with 6 patients. Bile samples were collected on days 1, 3, 5, and 7 after surgery, and MILLIPLEX assay was used to measure the levels of 17 cytokines. R software was used to perform principal component analysis (PCA) of bile cytokines and clinical indices and gene ontology (GO) enrichment analysis of bile cytokines. The two-independent-samples t-test was used for comparison of normally distributed continuous data between two groups; The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups. A Spearman correlation analysis was performed to evaluate the correlation between clinical indices and bile cytokines. ROC curve analysis was used to evaluate the predictive value of cytokines in bile and clinical indices for liver injury after liver transplantation. ResultsCompared with the mild liver injury group, the severe liver injury group had significantly higher expression levels of bile Fractalkine (Z=-2.828, P=0.003), soluble CD40 ligand (sCD40L) (Z=-2.850, P=0.008), interleukin-4 (Z=-2.398, P=0.017), CXCL10 (Z=-2.475, P=0.023), and macrophage inflammatory protein-1α (Z=-1844, P=0.043). The correlation analysis showed that on day 1 after liver transplantation, aspartate aminotransferase, ALT, and lactate dehydrogenase were positively correlated with the levels of several cytokines in bile (all P＜0.05). The area under the ROC curve of Fractalkine, sCD40L and AST were 0.933 (0.812-1.000), 0.833 (0.589-1.000) and 0.917 (0.779-1.000), respectively, suggesting that AST and Fractalkine and sCD40L in bile on the first day after liver transplantation have significant predictive value for liver injury. The results of PCA showed that bile cytokines combined with clinical indices on day 1 after liver transplantation could better distinguish the patients with mild liver injury from those with severe liver injury. GO analysis showed that bile cytokines were associated with positive feedback regulation of external stimulus, cell chemotaxis, receptor ligand activity, cytokine activity, and cytokine-cytokine receptor interaction. ConclusionFractalkine and sCD40L in bile can predict the degree of liver injury after liver transplantation.