中文摘要：

目的探讨丝裂原活化蛋白激酶（MAPK）／转录因子活化蛋白-1（AP-1）信号通路在调控苯并（a）芘[B（a）P]致人胚肺成纤维细胞（HFLF）周期改变中的作用。方法用AP-1荧光素酶报告基因技术检测AP-1荧光素酶活力，流式细胞术测定细胞周期时相分布，免疫印迹法检测MAPK[包括细胞外调节蛋白激酶（ERK）、c-Jun氨基末端激酶（JNK）和p38激酶]总量及磷酸化水平，用MAPK显性失活突变体（DN）（DN-ERK2、DN-JNK1和DN-p38）证明通路的上下游关系。结果2μmol／LB（a）P分别处理细胞0、6、12、24h，AP-1活力在12h达峰值，是对照组的2．22倍，差异有统计学意义（P〈0．05）；ERK1／2、JNK1／2和p38蛋白激酶的磷酸化水平明显提高，分别是对照组的2．5、14．0和2.1倍；B（a）P处理组s期细胞比例（50．2％±4．6％）与对照组（16．7％±8.1％）相比明显增加，差异有统计学意义（P〈0．01）；ERK2和州K1显性失活突变体的过表达均可明鼎降低B（a）P诱导的AP-1活力增强，并且明显降低B（a）P处理组S期细胞比例（分别为33．3％±1．7％，30．8％±3．9％），差异均有统计学意义（P〈0．05）；p38显性失活突变体的过表达对B（a）P引起的AP-1活力增强及S期细胞比例增加无影响。AP-1化学抑制剂姜黄素（20μmaol／L）可明显降低B（a）P引起的S期细胞比例增加（13．6％±2．9％），差异均有统计学意义（P〈0．05）。结论ERK和JNK通过活化AP-1介导B（a）P诱导的细胞周期改变；而B（a）P涛导的AP-1活力增强及细胞周期改变与p38无关。

英文摘要：

Objective To study the role of mitogen activated protein kinase （MAPK）/activator protein-1 （AP-1） pathway in benzo（a）pyrene （B（a）P）-induced changes of cell cycle in human embryo lung fibroblasts （HELF）. Methods AP-1 luciferase activity was determined by the Luciferase reporter gene assay using a luminometer. The expression levels and activity of extracellular signal-regulated protein kinase（ERK）, c-Jan NH2-terminal kinase（JNK） and p38 were determined by Western blot. Flow cytometric analysis was employed to detect the distributions of cell cycle. The dominant negative mutant of ERK2, JNK1 and p38 were applied to detect the upstream or dowustream relationship of signaling pathways. Results B（a）P treatment resulted in a marked activation of AP-1 and its upstream MAPK,including ERK,JNK and p38 in human embryo lung fibroblasts （HELF）. B（a）P exposure also led to increase the population of cells at S phase compared to control （ P 〈 0.01 ） with a concomitant decline of cells at G1 phase. B（a）P-induced cell cycle alternation was markedly impaired by stable expression of a dominant negative murat of ERK2 or JNK1, but not p38. B（a）P-induced AP-1 transactivation was inhibited by the overexpression of dominant-negative mutant of ERK2 or JNK1, but not p38. Inhibition of the activation of AP-1 by curcumin, a chemical inhibitor of AP-1, significantly inhibited the cell cycle changes in response to B （a）P treatment. Conclusion ERK and JNK, but not p38, mediated benzo（a）pyrene-induced cell cycle changes by AP-1 transactivation in HEIY.