镍冶炼烟尘对大鼠肺细胞凋亡相关蛋白表达水平的影响

Effect of nickel-smelting fumes on expression of apoptosis related proteins in rat lung cells

目的探讨镍冶炼烟尘对大鼠肺组织细胞凋亡相关蛋白p-JNK、Bax、Caspase-9和Caspase-3表达水平的影响。方法健康Wistar雄性大鼠40只,随机分为5组:对照组及镍冶炼烟尘0.50、1.00、2.00、4.00 mg/kg组,第1天及第16天非暴露式气管内滴注受试尘,30 d处死。Hoechst33258法观察肺内细胞形态学改变;分光光度法测定肺组织匀浆中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)的含量;免疫印迹(Western blot)法检测肺细胞p-JNK、Bax、Caspase-9和Caspase-3蛋白表达水平。结果与对照组比较,各染毒组大鼠肺组织细胞凋亡率均增高,差异有统计学意义(P<0.05);4.00 mg/kg染毒组细胞出现胞核固缩碎裂等凋亡早期形态学特征;各染毒组大鼠肺组织中SOD、GSH-Px活力较对照组显著降低,MDA含量显著升高,差异有统计学意义(P<0.05);染毒组大鼠肺组织Bax蛋白表达均高于对照组(P<0.05),肺组织p-JNK、Caspase-9、Caspase-3蛋白表达水平显著高于对照组(P<0.05)。结论镍冶炼烟尘引起大鼠肺组织氧化损伤,同时促进p-JNK、Bax、Caspase-9和Caspase-3蛋白表达,最终产生凋亡。

Objective To investigate the effect of nickel-smelting fumes on the expression of apoptosis related proteins in rat lung cells. Methods 40 healthy male Wistar rats were fed for 30 days and randomly divided into four nickel-smelting fumes exposed groups and a control group. The exposed groups were administrated by non-exposed intratracheal instillation of nickel-smeltlng fumes at dose of 0. 50, 1.00, 2.00, 4. 00 mg/kg in the first day and 16 days, respectively. Morphological changes of lung were observed with Hoechst 33258 method, the activities of SOD and GSH-Px, level of MDA were determined by spectrometer, and Western blotting technique was used to detect the protein expression level of p-JNK, Bax, Caspase-9 and Caspase-3 in rat lung cells. Results Compared with control group, apoptosis rate of all the exposed groups were increased （P〈0.05）, 4. 00 mg/kg nickel-smehing fumes treated group even appeared early changes of apoptosis, such as nuclear contraction and nuclear fracture etc. The activities of SOD and GSH-Px were significantly lower than those of control group, while the levels of MDA were rised in nickel treated groups. Simultaneously, the expression of Bax increased in 1.00, 2. 00, 4. 00 mg/kg nickel-smelting fumes treated groups as compared with that of control group （P 〈0. 05）. Additionally, the expression of p-JNK, Caspase-9, Caspase-3 were all significantly increased in each nickel treated group （P〈0. 05）. Conclusion Nickel-smelting fumes can induce oxidative stress, promote the expression of apoptosis related proteins as p-JNK, Bax, Caspase-9 and Caspase-3, and finally induce apoptosis.