Objective To investigate the effect of trichostatin A(TSA),a histone deacetylase inhibitor, on s-100-induced autoimmune hepatitis in mice.Methods A total of 26 six-week-old male C57BL/6 mice were randomly divided into control group,model group and TSA group(six in each group),and the rest 8 mice were used to extract the s-100 protein from liver tissue.Mice of model group and TSA group were injected intraperitoneally with s-100 with complete Freund's adjuvant to induce autoimmune hepatitis model.At day 21, TSA group mice were injected intraperitoneally with TSA 2 mg/(kg·d)for 7 days,and 0.9% sodium chloride solution containing 1% dimethyl sulfoxide was injected into the control and model group mice.Alanine transaminase(ALT)and aspartate aminotransferase(AST)in serum were measured and liver histopathology was observed.The protein levels of nuclear factor(NF)-κB and acetylated histone H3 in liver tissue were detected by Western Blot.The hepatic mRNA levels of NF-κB,HDAC3,toll-like receptor 4(TLR4)and TNF-α were measured by real-time PCR.ELISA was used to determine the TNF-α in serum.The results were analyzed with t test.Results The serum levels of ALT in control group,model group and TSA group were(122.00 ± 45.29),(459.33 ± 167.58)and(217.33 ± 49.25)U/L,respectively.The differences between model group and control group or TSA group were significant(t=4.76 and 3.41,respectively,both P<0.05).The serum levels of AST in control group,model group and TSA group were(127.83 ± 18.55),(389.67 ± 87.14)and (249.50 ± 71.72)U/L,respectively.The differences between model group and control group or TSA group were also significant(t= 7.20 and 3.04,respectively,both P< 0.05).The inflammation of the liver histopathology induced by s100 was alleviated by TSA.The relative expressions of NF-κB protein,NF-κB mRNA,TNF-α mRNA,HDAC3 mRNA and TLR4 mRNA in the liver tissue of model group mice were 2.43 ± 0.42,9.51 ± 0.36,10.53 ± 0.74,2.90 ± 0.22,and 4.50 ± 0.73,respectively,which were significantly higher than those of the control group(1.28 ± 0.49,1.28 ± 0.49,1.06 ± 0.14,1.72 ± 0.73,and 1.01 ± 0.31, respectively)(t=4.68,37.14,30.69,4.33 and 10.85,respectively,all P <0.05).In TSA group,the relative expressions of NF-κB protein,NF-κB mRNA,TNF-α mRNA,HDAC3 mRNA and TLR4 mRNA were decreased(1.30 ± 0.36,1.30 ± 0.36,2.38 ± 0.36,2.13 ± 0.32 and 2.40 ± 0.51,respectively),which were statistically lower than those in model group(t=4.58,30.62,24.12,2.81 and 5.81,respectively,all P<0.05).The serum TNF-α levels in control group,model group and TSA group were(122.37 ± 68.12), (1361.44 207.13)and(691.64 ± 162.12)ng/L,respectively.Compared with model group,the differences were statistically significant(t=13.92 and 6.24,respectively,both P<0.05).The relative expression of ac-H3 protein in the model group was 1.10 ± 0.08,which was higher than that in the control group 0.96 ± 0.17(t=2.27,P<0.05).That in TSA group was 1.30 ± 0.04,which was higher than the model group(t=-0.30, P <0.05).Conclusion Histone deacetylase inhibitor TSA alleviates autoimmune hepatitis by enhancing histone acetylation and inhibiting NF-κB and inflammatory factors.

Objective To investigate the effect of high-fat diet(HFD)on liver damage caused by autoimmune hepatitis(AIH)in mice.Methods Fifty C57BL/6 male mice were divided randomly into four groups:standard chow(SC)group,HFD group,AIH + SC group and AIH+ HFD group.AIH model was built after feeding for one week and all mice were sacrificed after four weeks.Liver and spleen tissues and serum were collected. Liver histopathology was detected by HE staining. Serum alanine aminotransperase(ALT)and aspartate aminotransferase(AST)levels were measured.Western blot analysis and real-time polymerase chain reaction(PCR)analysis were used to test the expressions of NLR pyrin domain containing 3(NLRP3)and cysteinyl aspartate specific proteinase 1(Caspase-1).The concentrations of interleukin(IL)-6,IL-1β and tumor necrosis factor(TNF)-α were analyzed using enzyme linked immunosorbent assay technology.The amount of Th17 cells in spleen was analyzed by FACS.Means among groups were analyzed with one-way ANOVA.SNK-q analysis was used for groups with homogeneity of variance, while nonparametric test was used for groups with variance nonhomogeneity.Results Histologically,the H&E staining of liver tissue from HFD group showed adipose degeneration,and there was inflammation around vessel in AIH+SC group.Moreover,in AIH+HFD group,the inflammation was more serious with mildly adipose degeneration.Compared with SC group,serum levels of ALT and AST increased in HFD group and AIH +SC group,and greatest increase was observed in AIH+ HFD group.The differences were statistically significant(F=57.12 and 37.58, both P<0.05).The proportions of Th17 cells in SC group,HFD group,AIH+ SC group and AIH+HFD group were(2.98 ± 0.90)%,(6.89 ± 0.99)%,(6.47 ± 1.08)% and(9.96 ± 0.83)%, respectively.The differences among all groups were statistically significant(F=54.05,P<0.05).The concentrations of IL-1β,IL-6 and TNF-α in each group were as follows:SC:IL-1β[(7.62 ± 2.81)ng/L],IL-6 [(106.54 ± 53.08)ng/L],T NF-α[(107.26 ± 36.20)ng/L];HFD:IL-1β[(25.06 ± 7.09)ng/L],IL-6 [(220.11 ± 47.41)ng/L],TNF-α[(273.77 ± 33.62)ng/L];AIH+SC:IL-1β[(17.49 ± 5.68)ng/L],IL-6 [(260.73 ± 50.29)ng/L],TNF-α[(250.49 ± 81.63)ng/L];AIH+ HFD:IL-1β[(52.04 ± 10.22)ng/L], IL-6[(785.93 ± 70.91)ng/L],TNF-α[(913.97 ± 64.57)ng/L].The differences were statistically significant(F=44.66,242.15 and 233.49,respectively,all P<0.05).The expressions of NLRP3 and Caspase-1 were significantly increased in AIH+ HFD group than the other three groups(all P<0.05). Conclusions High-fat diet potentiates liver damage induced by autoimmune hepatitis,which might relate to the secretion of pro-inflammatory cytokines,the activation of Th17 cells and the NLRP3 inflammasome as well as pyroptosis.

Objective To study the immunoregulatory effect of sodium butyrate(NaB)on T helper cell 17(Th17)and the effect on toll-like receptor 4(TLR4)signal pathway in autoimmune hepatitis (AIH).Methods Fifty male C57BL/6 mice(6 weeks of age)according to the random number table method divided into control group(n=10),AIH group(n=10),NaB group(n=10)and high roughage diet(HRD)group(n=10),and the other ten mice were used to extract hepatic sytosolic S-100.After the establishment of AIH model,mice in NaB group were given sodium butyrate 500 mg/(kg·d)by gavage and those in HRD group were fed with high-fiber stuff.After 3 weeks of treatment,all the mice were sacrificed.The pathological change was observed.The serum levels of alanine aminotransferase(ALT), aspartate transaminase(AST),IL-17A and TNF-α,the proportion of Th17 in spleen,the expression levels of TLR4 and myeloid differentiation factor 88(MyD88)in liver were observed in each group.The tests of normality and homogeneity of variance were used to compare the means of each group.One-way analysis of variance and multiple comparative analyses were used in the statistical analysis.Results HE staining showed that inflammatory cell infiltration and hepatocyte necrosis were significantly reduced in mice treated with NaB and HRD compared to AIH group.Serum ALT levels in control group,AIH group,NaB group and HRD group were(24.833 ± 2.229),(88.333 ± 9.543),(27.167 ± 3.189)and (29.833 ± 6.113)U/L,respectively,while AST levels in each group were(97.00 ± 14.953),(285.000 ± 35.434),(139.500 ± 38.976)and(127.167 ± 28.687)U/L,respectively.The differences among groups were all statistically significant(F=156.49 and 44.118,respectively,both P<0.01).The proportion of Th17 in spleen and the expressions of the transcription factors retinoid-related orphan receptor gamma t in the spleen of the NaB group and HRD group were significantly lower than those of AIH group.The differences were statistically significantly(F=21.780 and 68.283,respectively,both P<0.05).The expressions of TLR4 and MyD88 in liver of AIH group were significantly higher than control group,but those were inhibited in NaB group and HRD group.The differences were statistically significantly(F= 26.235 and 28.293,respectively,both P<0.01).The expressions of IL-17 and TNF-α in liver and serum decreased in NaB group and HRD group.Conclusion NaB exerts an immunoregulatory effect in AIH and improves inflammatory reaction in liver.