中文摘要：

目的探讨丝裂原活化蛋白激酶（MAPKs）信号通路在调控苯并（a）芘[B（a）P]诱导人胚肺成纤维细胞（HELF）c—Jun活化中的作用。方法2．0μmol/LB（a）P处理HELF0、3、6、12、24h后或加入不同浓度B（a）P（0．0、0．5、1．0、2．0μmol/L）处理12h后，通过免疫印迹法检测B（a）P对细胞c-Jun活性的影响；利用p38、c—Jun氨基末端激酶（JNK）以及细胞外调节蛋白激酶（ERK）的显性失活突变体分别阻断p38、JNK和ERK活性后，观察3种MAPKs信号分子与B（a）P诱导c-Jun活化之间的关系。结果在所观察的B（a）P作用时间和浓度范围内，c—Jun蛋白表达量无明显变化；B（a）P可诱导细胞内磷酸化c—Jun（Ser63／Ser73）水平增高，并随着作用时间的延长，细胞内c—Jun的磷酸化水平也逐渐增强，至12h达到峰值（1．61±0．12，1．82±0．18），c-Jun磷酸化Ser63、Ser73与actin灰度比值分别是对照组的20．1倍、15．2倍，作用24h时细胞内c-Jun磷酸化水平呈现下降趋势，而且随着B（a）P浓度的增加，细胞内c-Jun的磷酸化水平也逐渐升高，呈现剂量-反应关系；使用显性失活突变体分别阻断JNK和ERK活性均可明显抑制B（a）P诱导细胞c—Jun磷酸化水平增加，但是阻断p38活性对B（a）P诱导细胞c—Jun磷酸化水平升高无明显影响。结论JNK和ERK信号通路调控B（a）P诱导的HELF细胞c—Jun活化，B（a）P促进c-Jun磷酸化的过程与p38信号通路无关。

英文摘要：

Objective To investigate the role ofmitogen activated protein kinases （MAPKs） signaling pathways in the regulation of benzo（a）pyrene （B（a）P）-induced c-Jun activation in human embryo lung fibroblasts （HELFs）. Methods HELFs were cultured with 2.0 μmol/L B（a）P for various time （0, 3, 6, 12, 24 h） or with various concentration of B（a）P （0.0, 0.5, 1.0, 2.0 μmol/L） for 12 h. Western blot was performed to examine the effect of B（a）P on c-Jun activation. The dominant negative mutants of p38, c-Jun NH2-terminal kinase （JNK） and extraeellular signal-regulated protein kinase （ERK） were applied to establish stable transfeetant, and to detect the relationship of MAPK signal molecules and c-Jun activation in B（a）P-treated cells. Results B（a）P treatment resulted in a marked activation of c-Jun in time-dependent manner with a peak at 12 h （the densitometric ratios of phosphorylated c-Jun Ser63, Ser73 to aetin were 20.1, 15.2 times for control, respectively ） and in dose-dependent manner. However, there was no evident change on total c-Jun expression in B（a）P-treated HELFs. Moreover, B（a）P-indueed activation of c-Jun was inhibited by stable expression of dominant negative mutants of JNK or ERK, but not by dominant negative mutant of p38. Conclusion JNK and ERK signaling pathways, but not p38 pathway regulate B（a）P-indueed c-Jun activation in HELFs.