The Inhibitory Effect Of Apolipoprotein AI Mimetic Peptide D-4F On Steatosis And Inflammatory

ObjectiveThe experimental Apo E-/-mice model which is similar with the process of humannon-alcoholic fatty liver disease was established by high fat diet，observing the effects ofApo AI mimetic peptide D4F on lipid metabolism in the liver of the mice，investigating theeffects of D4F on steatosis and inflammatory of the mice liver，and exploring the possiblemechanism of the process，and providing the basis clinical drugs on nonalcoholic fattyliver disease treatment.Method248-week-old male Apo E-/-mice which were fed with high-fat (15.8%) and highcholesterol(1.25%)diet for two weeks were stochastic divided into three groups (n=8)，respectively，intraperitoneal injection of physiological saline (model group)， disorganizedmimetic peptide sD4F (1mg/kg· D，sD4F group) and Apo AI mimetic peptide (D4F1mg/kg·D，D4F group).The alike date old male C57BL/6J mice fed with normal food andintraperitoneal injection of physiological saline as control group. All of them wereexecuted after six weeks，the assay of TNF-α and IL-6of the mice were detected by ELISAmethod，and take out the liver tissue of mice，using HE staining and oil red O staining toobserve the pathological changes and liver steatosis degree evaluation. To detect theexpression and distribution of NF-κB and TNF-α in liver tissues of the mouse byimmunohistochemical method，using the Western Blotting method at the same time to detect the content of NF-κB and TNF-α of the mice liver tissue. The experimental data wastested with SPSS13.0software，the comparison between two groups by single factoranalysis of variance，experimental data with the mean±standard deviation，P<0.05wasconsidered that the differences have statistical difference.Results1.Mice liver biopsy results showed that: a large number of lipid droplets accumulationin liver cells of the model group and sD4F group mice under microscope, and withdifferent degrees of fatty degeneration and infiltration of inflammatory cells in lobules; butthe liver cell steatosis of mice in D4F group were obviously reduced，interlobularinflammatory cell infiltration were significantly decreased，compared with the controlgroup mice，it had no significant difference.2.The testing results of serum cytokines showed：compared with the control group，the standard of TNF-α and IL-6of the tall fat food group were obviously increased，thedifference was statistically significant (P<0.05); compared with the model group，thestandard of TNF-α and IL-6of the tall fat food group were significantly decreased，thedifference was statistically significant (P<0.05); the comparing between sD4F group andmodel gr，there was no significant difference in each index.3.Immunohistochemistry results showed that：TNF-α in normal group’s mouse livercells almost had no expression，but it had significant expression in mice liver cells of themodel group (P<0.05)，compared with the model group，the content of TNF-α of D4F grobviously reduced in the liver cells (P<0.05); NF-κB expression in normal mouse livercytoplasm，almost no expression in the nucleus，but significantly expressed in the micehepatocyte cytoplasm and nucleus of the model group (P<0.05)，compared with the modelgroup，NF-kappa B expression in the hepatocyte nucleus of the D4F group obviouslydecreased (P<0.05); the comparing between sD4F group and model group，there was nosignificant difference in each index.4.Western blotting results showed：NF-κB and TNF-α in normal group’s mouse livercells almost had no expression，but it had significant expression in mice liver cells of themodel group (P<0.05)，compared with the model group，the expression of NF-κB andTNF-α of D4F group significantly reduced in the liver cells (P<0.05);the comparingbetween sD4F group and model group，there was no significant difference in each index.Conclusions High fat diet induced Apo E-/-mice liver lipid deposition，and secondary inflammationof the liver; Apo AI mimic peptide D4F can reduce the deposition of high fat diet Apo E-/-mice liver lipid，and can reduce the liver tissue inflammatory changing，indicating that D4Fcan prevent mice from liver fatty degeneration and inflammatory; NF-κB may have a rolein the pathogenesis of nonalcoholic fatty liver disease; Apo AI mimic peptide D4F playingeffects on nonalcoholic fatty liver disease may be related to the inhibition of the expressionof NF-κB pathway and secondary inflammatory factor TNF-α and IL-6releasing.