Effect of trichostatin A on s-100-induced autoimmune hepatitis in mice

Abstract

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. Key words: Histone deacetylase; Trichostatin A; NF-kappa B; Tumor necrosis factor-alpha; Hepatitis, autoimmune