SIRT1过表达的脂肪间充质干细胞对四氯化碳诱导小鼠肝纤维化的影响

Effect of SIRT1 Over-expressed Adipose Mesenchyma Stem Cells on CCl4-induced Liver Fibrosis in Mice

目的探讨沉默信息调节因子2相关酶1(SIRT1)过表达的脂肪间充质干细胞(ADSCs)对小鼠肝脏纤维化的影响及其机制。方法采用酶消化法分离培养C57BL/6小鼠ADSCs,并构建过表达SIRT1的ADSCs。应用四氯化碳诱导小鼠肝纤维化模型,按随机数字表法分为正常组、模型组、治疗组和对照组,治疗组和对照组分别将SIRT1过表达、空载体腺病毒修饰的ADSCs经尾静脉移植。4周后处死小鼠,收集血清和肝脏组织,ELISA法检测血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)水平;PCR法检测转化生长因子-β1(TGF-β1)、Ⅰ型胶原(CollⅠ)和α-平滑肌肌动蛋白(α-SMA)的mRNA表达情况。结果模型组、对照组和治疗组血清AST、ALT、IL-6和TNF-α水平均高于正常组,且治疗组低于模型组(P<0.05)。模型组、对照组和治疗组小鼠肝脏组织TGF-β1、CollⅠ、α-SMA的mRNA表达均高于正常组,且治疗组低于模型组(P<0.05)。结论过表达SIRT1的ADSCs可抑制四氯化碳诱导的小鼠肝纤维化,改善肝脏功能。其机制可能是通过调高SIRT1的表达,从而减轻炎性反应、抑制肝星状细胞的活化发挥作用。

Objective To investigate effect of silent matingtype information regulation 2 homolog 1(SIRT1)over-expressed adipose mesenchyma stem cells(ADSCs)on liver fibrosis in mice and its mechanism.Methods C57BL/6 mice's ADSCs were separately cultured by using enzyme digestion,and over-expressed SIRT1 ADSCs were constructed.Liver fibrosis mice models were induced by carbon tetrachloride(CCl 4),and then the models were divided into normal group,model group,treatment group and control group by random digits table method.Over-expressed SIRT1 ADSCs and blank vector adenovirus transferred ADSCs were performed vein transplantation in treatment group and control group respectively.Mice were sacrificed 4 weeks later,and serum and liver tissues were collected.Enzyme linked immunosorbent assay(ELISA)was used to detect levels of serum alanine transaminase(ALT),aspartate transaminase(AST),tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6).Polymerase chain reaction(PCR)method was used to detect mRNA expressions of transforming growth factor-β1(TGF-β1),typeⅠcollagen(CollⅠ)andα-smooth muscle actin(α-SMA).Results Serum levels of AST,ALT,IL-6 and TNF-αin model group,control group and treatment group were significantly higher than those in normal group,and the levels in treatment group were significantly lower than those in model group(P<0.05).The mRNA expressions of TGF-β1,CollⅠα-SMA in liver tissues in model group,control group and treatment group were significantly higher than those in normal group,and the expressions in treatment group were significantly lower than those in model group(P<0.05).Conclusion Over-expressed SIRT1 ADSCs may inhibit CCl 4-induced liver fibrosis and improve liver function in mice.Its mechanism may be through increasing SIRT1 expression to reduce inflammatory reaction and inhibit activation of hepatic stellate cells.