Alantolactone Regulates LXRs-STAT3 Signaling Pathway To Improve The Process Of Liver Fibrosis

Objective:The purpose of this study was to investigate the mechanism of Alanto lactone(ALA)to improve thioacetamide(TAA)-induced liver fibrosis in mice by mediating LXRs-STAT3 cross-talk,and provide an effective theoretical basis for the clinical drug treatment of liver fibrosis.Methods:In vitro experiments,hepatic stellate cells(HSCs and LX-2)were selected,and cells were stimulated with transforming growth factor(TGF-β)for 1 h in advance,and treated with different concentrations of ALA(1μM,5 βM for 4 h to extract total cell protein and RNA.The expression levels of LXRs,STAT3 protein and mRNA in the cells were detected,and further verified by immunofluorescence staining.In vivo experiments,C57BL/6 mice were selected,and all decimals were randomly divided into 6 groups.That is,the normal group,the TAA model group,and the drug-administered group were given gavage 10 mg/kg(low-dose group)or 20 mg/kg(high-dose)of ALA,and the positive control group were given gavage curcumin(Cur)20 mg/kg,and ALA(20 mg/kg)administration alone group.The normal group and the ALA alone group were given a standard diet.The TAA model,the ALA and curcumin treatment groups were intraperitoneally injected with TAA(100 or 200 mg/kg)to establish a liver fibrosis model.After 4 weeks,6 hours after the last intragastric administration,the mice were sacrificed and serum and liver tissues were collected to detect the levels of ALT and AST in the serum H&E staining,Masson staining,and Sirius scarlet staining were used to detect the pathological changes of liver tissue.The expression of LXRs,STAT3 and other proteins and mRNA in liver tissue were detected by Western blot,PCR and immunofluorescence.Results:In vitro,TGF-β can induce HSC activation and significantly increase the expression of liver fibrosis markers,while ALA can significantly reduce the liver fibrosis markers protein and mRNA expression of α-SMA,Collagen-I,TIMP1 in activated HSC cells.And ALA also significantly inhibit the release of IL-1α,IL-Iβ,caspase-1 and other inflammatory factors.Additionally,ALA can activate the expression of LXRa and LXRβin cells,inhibit the phosphorylation level of STAT3,and further inhibit the JAK/STAT3 signaling pathway,thereby improving liver fibrosis-Furthermore,through the SiRNA experiment,the interaction of LXRs-STAT3 was verified.The results of in vivo experiments showed that ALA can significantly reduce the levels of ALT andAST in the serum,and improve the histopathological changes in TAA-induced mice.At the same time,ALA significantly inhibited the protein and mRNA expression of TAA-induced liver fibrosis markersα-SMA,Collagen-I,TIMP1.Additionally,ALA significantly inhibited the release and cascade reaction of a series of inflammatory factors such as IL-1α,IL-1β,caspase-1.Furthermore,ALA activates and up-regulates LXRa and LXRβ protein and mRNA expression in TAA-induced mice,inhibits STAT3 phosphorylation,inhibits JAK2/STAT3 signaling pathway,and improves liver fibrosis.Conclusion:ALA can significantly reduce the expression of liver fibrosis markers and effectively inhibit the release of pro-inflammatory factors,which may improve liver fibrosis by mediating the interaction of LXRs-STAT3.