外源性甲状腺激素T3对酒精性肝纤维化小鼠肝细胞增殖和凋亡的影响

The effect of exogenous thyroid hormone T3 on liver cell proliferation and apoptosis in alcoholic liver fibrosis mice

目的探讨外源性甲状腺激素T3对酒精性肝纤维化小鼠肝细胞增殖和凋亡的影响。方法将38只6~8周龄健康SPF级C57BL/6N雄鼠分为正常对照组6只、模型组和3个不同剂量T3干预组每组各8只。对照组用TP4060C对照饲料喂养8周,模型组和T3干预组用TP4060A酒精饲料喂养8周并在第3周联合31.5%乙醇灌胃,建立酒精性肝纤维化模型。第6周起分别用不同剂量T3每天对干预组小鼠进行腹腔注射至第8周末。检测小鼠血清ALT、AST,取肝组织进行HE和天狼星红染色;免疫蛋白印记迹法检测PCNA、Caspase-9、a-SMA的相对表达水平。结果模型组小鼠ALT(35.544±4.039)U/L和AST(78.250±9.307)U/L比正常组ALT(14.336±3.553)U/L和AST(40.842±3.834)U/L都有所升高(P<0.05),但经低、中、高T3干预的小鼠血清ALT分别为(25.242±3.469)、(22.940±4.566)、(27.556±4.609)U/L,均低于模型组小鼠(P<0.05);同时T3干预组小鼠的AST分别为(52.213±9.664)、(40.938±7.565)、(48.696±12.443)U/L相比于模型组小鼠也有不同程度的降低(P<0.05)。五组小鼠的PCNA(0.475±0.019、1.001±0.034、0.876±0.015、0.618±0.035、0.906±0.092),Caspase-9(0.832±0.024、1.23±0.0541.040±0.035、0.943±0.036、1.114±0.072),a-SMA(0.592±0.046、1.037±0.043、0.892±0.028、0.715±0.034、0.854±0.047),模型组三种蛋白的相对表达量均比正常组有所升高(P<0.05),而T3干预组的三种蛋白相对表达量都比模型组有所降低(P<0.05)。结论适当补充甲状腺激素T3可以抑制肝纤维化小鼠HSC的活化,进而抑制肝细胞凋亡。

Objective Exploring the effects of exogenous thyroid hormone T3 on liver cell proliferation and apoptosis in alcoholic liver fibrosis in mice.Methods Thirty eight healthy SPF grade C57BL/6N male rats aged 6-8W were divided into five groups:six mice in the normal control group,eight in the model group and eight in the three different doses of T3 intervention groups.The control group was fed with TP4060C liquid control diet for 8W,the model group and T3 intervention groups were fed with TP4060A alcohol diet for 8W and gavage with 31.5%alcohol from the 3rd week to establish an alcoholic liver fibrosis model.Starting from the 6th week,mice in the intervention group were injected intraperitoneally with different doses of T3 daily until the 8th week.Blood samples were taken from the eyeballs of all mice to detect serum transaminase(ALT,AST)activity.Liver samples were dissected for HE staining and Sirius red staining;Western blot was used to detect the expression levels of PCNA,Caspase-9,and a-SMA.Results The ALT activity(35.544±4.039)and AST activity(78.250±9.307)in the model group were higher than those in the normal group(ALT activity:14.336±3.553;AST activity:40.842±3.834,P<0.05),but the serum ALT activity(25.242±3.469,22.940±4.566,27.556±4.609)in the T3 intervention groups was lower than that in the model group(P<0.05);At the same time,the AST activity of T3 intervention groups(52.213±9.664,40.938±7.565,48.696±12.443)was also decreased in varying degrees compared with the model group(P<0.05).Immunoblotting showed that PCNA(0.475±0.019,1.001±0.034,0.876±0.015,0.618±0.035,0.906±0.092),caspase-9(0.832±0.024,1.23±0.054,1.040±0.035,0.943±0.036,1.114±0.072),a-SMA(0.592±0.046,1.037±0.043,0.892±0.028,0.715±0.034、0.854±0.047)in the five groups of mice,the relative expression levels of the three factors in the model group were higher than those in the normal group(P<0.05),and the relative expression levels of the three factors in the T3 intervention group were lower than those in the model group(P<0.05).Conclusion Adequate supplementation of thyroid hormone T3 can inhibit the activation of HSC in liver fibrosis mice,thereby inhibiting liver cell apoptosis.