Role of thymosin β4 in treatment of non-alcoholic fatty liver disease in mice and its mechanism / 中华消化杂志

ABSTRACT

Objective To explore the role and mechanism of thymosin β4 (Tβ4) in the treatment of non-alcoholic fatty liver disease (NAFLD).Methods Forty male C57BL/J6 mice were divided into normal group,NAFLD group,low dose Tβ4 group and high dose Tβ4 group with 10 mice in each group.NAFLD mice model was established by feeding with high fat and high sugar diet for 16 weeks.The mice in low-dose Tβ4 group and high dose Tβ4 group were intraperitonealy injected with Tβ4 at 0.05 mg · kg-1 · d-1 and 0.20 mg · kg-1 · d-1,respectively,for eight weeks.The liver function indexes and serum tumor necrosis factor-α (TNF-α) level were detected;the pathological changes of liver tissue were observed under optical microscope and non-alcoholic fatty liver disease activity score (NAS) was evaluated.The protein expression levels of nuclear factor-κB p65 (NF-κB p65) and nuclear factor κB inhibit protein a (IκBa) at the protein level in liver tissue were measured by Western blotting method.The expression of TNF-α in liver tissue was detected by immunohistochemistry.Mean integral absorbance (MIA) was calculated.T test was performed for groups comparison.Results The levels of alanine aminotransferase (ALT),γ-glutamine transferase (GGT) and serum TNF-α levels of high dose Tβ4 group were all lower than those of NAFLD group ((28±17) U/L vs.(76±29) U/L,(61±39) U/L vs.(102±56) U/L,(144.1± 48.2) ng/L vs.(187.3±58.8) ng/L,respectively),and the differences were statistically significant (t=4.52,2.78 and 2.30,all P＜0.05).The NAS of low dose Tβ4 group and high dose Tβ4 group were both lower than that of NAFLD group (3.7±40.4,2.3±0.3 vs.4.6±0.3),and the differences were statistically significant (t=5.69 and 17.14,both P＜0.01).The relative expression level of Tβ4 protein of NAFLD group was lower than that of normal group (0.2±0.1 vs.1.4±0.6),and the difference was statistically significant (t=6.24,P＜0.01).The relative expression levels of Tβ4 and IκBa of high dose Tβ4 group were higher than those of NAFLD group (1.0±0.3,0.5±0.3 vs.0.2±0.1),and the differences were statistically significant (t=8.00 and 3.00,both P＜0.01).The relative expression level of NF-κB p65 in liver tissue of high dose Tβ4 group was lower than that of NAFLD group (0.6±0.3 vs.1.5±0.7),and the difference was statistically significant (t=3.74,P＜0.01).The MIA of high dose Tβ4 group was lower than that of NAFLD group (0.4±0.2 vs.0.7±0.3),and the difference was statistically significant (t=2.63,P＜ 0.01).Conclusion Tβ4 can effectively treat NAFLD probably through inhibiting the NF-κB pathway.