异烟肼致小鼠肝脏损伤和对Nrf2及GSTA1 mRNA表达的影响

Experimental study on the expressions of Nrf2 and GSTA1 gene during the isoniazid-induced liver injury in mice

目的研究在异烟肼(INH)致小鼠肝脏损伤进程中,核因子相关因子2(Nrf2)通路及其下游靶基因谷胱甘肽-S转移酶A1(GSTA1)mRNA的表达情况,为INH致肝损伤的预防和治疗提供依据。方法 64只昆明小鼠,随机分为8组,实验组分别为INH 90 mg/kg·d灌胃1 d、3 d、5 d、7d、2周、3周和4周组;对照组给予等容积蒸馏水灌胃。比色法检测肝组织中还原性谷胱甘肽(GSH)、丙二醛(MDA)含量及GSTs活力;应用SYBR Green实时荧光定量RT-PCR法检测肝组织中Nrf2、GSTA1 mRNA表达情况。结果用药2周后,血清ALT含量升高(P<0.001);用药5 d后可见肝组织病理形态学改变;用药5 d、7 d、2周和3周后肝组织中GSH含量明显低于对照组(P<0.001),7 d、2周和4周组肝组织中MDA含量高于对照组(P=0.002);5和7 d组GSTs活力降低(P=0.005),随后又上升至正常水平;4周时,Nrf2 mRNA表达比值增加至6.24倍(P=0.014);用药2、3和4周组GSTA1 mRNA表达上调(P<0.001);GSTA1和Nrf2 mRNA的表达有相关性(r=0.861,P=0.006)。结论在INH导致的肝损伤发生过程中,Nrf2及GSTA1基因表达上调,调节机体的Ⅱ相药物代谢能力,抵御药物毒性作用,提示及时激活Nrf2通路上调其下游靶基因可能会预防肝损伤的发生。

Objective To observe the expressions of Nrf2 and GSTA1 mRNA in mice liver induced by INH for the purpose of its prevention and treatment. Methods A total of 64 Kunming mice were randomly divided into 8 groups. The experimental mice were given isoniazid orally at 90 mg /kg body weigh at 1 d,3 d,5 d,7 d,2 w,3 w,4 w and the control group was given distilled water. GSTs activities and GSH、MDA contents in liver tissue were detected by colorimetry. SYBR Green Real-time RT-PCR was used to test the expressions of Nrf2 and SOD mRNA. Results The concentration of serum ALT increased significantly at 2w after treatment（ P〈0. 001）. The pathological changes of the liver were observed at 5 d. The concentration of GSH of tissues in 5,7,2 w,3 w groups were significantly lower than those in control group（ P〈0. 001） and MDA in 7 d,2 w,4 w groups were higher（ P = 0. 002）. The GSTs activity were significantly decreased at 5 d,7 d（ P = 0. 005）. Compared with control group,the Nrf2 mRNA expression ratio was up-regulated to 6. 42 fold（ P = 0. 014） in 4w; the GSTA1 mRNA expression ratio in 3 w and 4 w were increased（ P〈0. 001）. There was a relationship between the mRNA expression of Nrf2 and GSTA1（ r = 0. 861,P = 0. 006）. Conclusion In the development of liver injury by INH,the Nrf2 and GSTA1 gene expression upregulated,then adjust the ability of phase Ⅱdrug metabolism. It is suggested that the activation of timely Nrf2 access man be help people to combat the hepatic injury.