硫酸镍对大鼠肝脏细胞Caspase-3、Bax和Bcl-2蛋白表达的影响

Effect of Nickel Sulfate on the Protein Expression of Caspase-3,Bax and Bcl-2 in Rat Liver Cells

目的观察硫酸镍对大鼠肝脏细胞凋亡相关基因Caspase-3、Bax和Bcl-2蛋白表达以及氧化应激效应指标的影响,探讨镍诱导肝细胞凋亡的可能调控机制。方法选择健康Wistar雄性大鼠32只,硫酸镍1.25、2.50、5.00 mg/kg腹腔注射染毒,1次/d,连续30 d。采用Western Bloting技术检测各染毒组及对照组大鼠肝脏细胞中Caspase-3、bcl-2及Bax的蛋白表达水平;分光光度法测定各组肝脏组织匀浆中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活力、总抗氧化能力(T-AOC)及丙二醛(MDA)、过氧化氢(H2O2)的含量。结果镍可诱导大鼠肝脏细胞Caspase-3、Bax蛋白表达上调,Bcl-2蛋白表达下调;镍抑制肝脏组织匀浆中SOD、GSH-Px、CAT的活力,升高T-AOC、MDA和H2O2的水平,与对照组比较,硫酸镍5.0 mg/kg染毒组SOD和T-AOC水平变化明显(P<0.05),而硫酸镍2.5和5.0 mg/kg染毒组GSH-Px、CAT、MDA和H2O2水平变化明显(P<0.05)。结论硫酸镍诱导大鼠肝细胞凋亡可能与其诱导Caspase-3、Bax蛋白表达上调,Bcl-2蛋白表达下调以及氧化应激效应增强有关。

Objective To observe the effects of nickel sulfate （NiSO4） on the protein expression of Caspase 3, Bax and Bcl-2, and index of oxidative stress in order to explore the regulation mechanism of hepatic cells apoptosis induced by nickel sulfate. Methods 32 healthy male Wistar rats were divided into four groups including three NiSO4 exposed groups and a control group. The exposed groups were administrated intraperitoneally with NiSO4 at doses of 1.25, 2.50, and 5.00 mg/kg once a day for 30days respectively, and the control group was treated with normal saline under same condition. The protein expression level of Caspase 3, bcl-2 and Bax in rat liver cells were detected with Western blotting technique, and the activities of superoxide dismutase （SOD）, glutathione peroxidase （GSH-Px）, hydrogen peroxidase （CAT） and the content of malondialdehyde （ MDA）, total - antioxidative capability （ T - AOC）, and hydrogen peroxide （H2O2） were measured by Spectrophotometry. Results The protein expression of Caspase 3 and Bax were induced upward, and Bel-2 in NiSO： exposed groups was induced downward in rat liver cells. Nickel would inhibit the activities of SOD, GSFI- Px, and CAT and would elevate T- AOC, MDA and HzOz levels. Compared with the control group, in NiSO4 5.0 mg/kg group changes of SOD and T AOC were significant （P〈0. 05）, and in NiSO4 2.5 mg/kg and 5.0 mg/kg groups changes of GSH-Px, CAT, MDA and H2O2 levels were obvious in liver tissue homogenate （P〈 0.05）. Conclusions The apoptosis of rat liver cells induced by nickel sulfate could be related with the protein abnormal expression of Caspase3, Bax, Bcl-2 and the enhancement of oxidative stress effect in nickel sulfate exposure.