摘要目的 探讨石英暴露的人胚肺成纤维细胞(human embryonic lung fibroblast,HELF)中细胞周期蛋白D1(cyclin D1)-细胞周期依赖蛋白依赖激酶4(CDK4)蛋白的表达水平,同时探讨细胞外调节蛋白激酶(ERK)、JNK、p38和核转录因子(AP-1)等信号蛋白在石英诱导eyelin D1-CDK4蛋白表达改变中的作用.方法 石英刺激HELF后,收获细胞,检测cyclin D1和CDK4蛋白表达.选用特异化学抑制剂或分子抑制剂抑制ERK、JNK、p38或AP-1的活性后,分别采用免疫细胞化学和免疫蛋白印迹方法检测HELF中cyclin D1和CDK4蛋白表达变化.结果 HELF暴露于石英粉尘2h后,cyclin D1和CDK4蛋白表达水平分别为(7.91±0.29)x103和(5.17±0.28)x104,均明显低于HELF组,差异有统计学意义(P＜0.05).用ERK的化学抑制剂或分子抑制剂抑制ERK的活力后,能够防止石英诱导的cyclin D1和CDK4蛋白表达降低.用SP600125抑制JNK的活力后,可以防止cyclin DI和CDK4蛋白表达降低.但是抑制p38的活力对石英诱导的cyclin D1和CDK4蛋白表达降低均没有作用.用姜黄素抑制AP-1的活性后,只能防止石英诱导的CDK4的表达降低,而对cyefin D1表达降低没有影响.结论 石英诱导HELF中cyclin D1和CDK4蛋白表达降低与ERK和JNK蛋白激酶有关.AP-1与石英诱导的CDK4蛋白表达降低有关.

abstractsObjective To study the expression level of cyclin D1-CDK4 protein in human embryonic lung fthroblasts (HELF) induced by quartz, and to study whether the expression level of eyclin D1-CDK4 protein mediated by mitogen activated protein kinase (MAPK)/(AP-1 )signaling pathways. Methods Cells were harvested after stimulation 2h for the detection of cytokines. Cyclin D1 and CDK4 (cyclin dependent kinase 4)proteins was measured by immunocytochemistry(IC) and Western blot(WB). Results The exposure of HELF to crystalline quartz for 2 hours could cause the decrease of cyclin D1 and cyclin dependent kinase 4 (CDK4)protein expression level, (7.91±0.29)x 103 and (5.17±0.28 )×104 respectively, which was lower than that of the HELF group (P＜0.05). AG126 (chemical inhibitor of the extracel-lular signalregulated protein kinase (ERK) signaling pathway) and the dominant negative mutant of ERK2 (molecular inhibitor of ERK2), prevented the decrease of cyclin D1 and CDK4 protein expression level. The chemical inhibitor of c-Jun NH2-terminal amino kinase (JNK),SP600125,could prevent both eyclin D1 and CDK4 protein expression level decrease. ButSB203580, the chemical inhibitor of p38, prevented neither cyclin D1 nor CDK4 protein expression level decrease. Curcumin could prevent CDK4 protein expression level decrease but not cyclin D1 protein. ConclusionERKs and JNKs, but not p38, are responsible for the decrease of eyclin D1 and CDK4 protein expression level in HELF induced by quartz. AP-1 is responsible for the decrease of CDK4 expression level but not that of cyclin D1.