牛磺酸对大鼠肢体缺血-再灌注后肝脏TNF-α、Caspase-3表达及细胞凋亡的影响

Effects of taurine on TNF-α,Caspase-3 expression and apoptosis of liver after limbs ischemia-reperfusion in rats

目的观察肢体缺血-再灌注(LI-R)后大鼠肝脏损伤中肿瘤坏死因子α(TNF-α)、半胱天冬氨酸蛋白酶(Caspase)3表达及细胞凋亡的发生和牛磺酸预处理后对其的影响。方法Wistar大鼠建立LI-R损伤模型后,随机分为对照组、LI-R组和牛磺酸+LI-R(TR)组。测定各组动物肝组织丙二醛(MDA)、髓过氧物酶(MPO)、肝组织钙含量、TNF-α水平;免疫组化法观察Caspase-3蛋白表达;利用琼脂糖凝胶电泳观察DNA梯状条带;TUNEL法检测各组肝脏细胞的凋亡情况。结果与对照组比较,LI-R组和TR组大鼠肝脏各损伤性指标、TNF-α水平及Caspase-3蛋白表达增高,肝脏细胞DNA琼脂糖凝胶电泳可见梯状条带,TUNEL染色结果显示凋亡百分率明显升高(P<0.05)。TR组上述各项指标较LI-R组显著降低(P<0.05),肝脏细胞DNA琼脂糖凝胶电泳显示梯状条带不明显。结论细胞凋亡参与了LI-R肝损伤的发生;牛磺酸预处理可降低TNF-α、Caspase-3表达,从而减少大鼠LI-R后肝脏细胞凋亡的发生。

Objective To investigate the changes of tumor necrosis factor（TNF）-α,Caspase-3 expression and apoptosis following limbs ischemia-reperfusion（I-R）,and the effect of pretreatment with taurine on liver injury in rats.Methods After the model of limbs I-R injury was established,Wistar rats were randomized into 3 groups of control group,I-R group and T-R group（pretreated with taurine）.The levels of malondialdehyde（MDA）,myeloperoxidase（MPO）,calcium and TNF-α in the liver tissue were measured.The expressions of Caspase-3 in liver tissues were tested by immunohistochemistry method.DNA fragmentation was observed and analyzed by agarose gel electrophoresis.Apoptosis was detected by TUNEL method.Results Compared with control group,MDA,MPO,calcium,TNF-α and Caspase-3 were increased in groups of I-R and TR,which were lower in group TR than those in group I-R（P〈0.05）.Conclusion Apoptosis participates in the liver injury after limb I-R.Taurine can attenuate the apoptosis of the liver injury through decreasing the levels of TNF-α and Caspase-3.