摘要
目的 探讨p38蛋白激酶信号传导的过程及其在细胞中的特异性作用机制。方法 应用间接荧光标记免疫探针技术及共聚焦激光扫描技术观察单核细胞中p38蛋白激酶的分布及LPS对其分布的影响。结果p38在未受刺激的静息单核细胞及内皮生长因子（EGF）刺激的单核细胞胞浆和胞核中荧光强度均呈弥散性分布；脂多糖（LPS）刺激使细胞核区的荧光强度明显增强，而胞浆区域的荧光强度降低。激酶动力学的研究显示，p38激活先于p38移位。LPS刺激后30 min，p38激酶活性即达到高峰，随后2 h内逐步下降，p38激酶活性呈一过性增高；LPS刺激45 min后，核区荧光强度达到峰值，且在2 h内维持在高水平。结论 单核细胞由LPS激活后，其p38蛋白激酶由胞浆转位到胞核，反应具有一定的特异性；p38移位入核依赖于p38磷酸化活化及由细胞浆移位到细胞核是一系列连续发生的事件。
Objective To elucidate the mechanisms of specific signal transduction of p38 MAPK. Methods Distribution of p38 MAP kinase in RAW264.7 cells and the influence of lipopolysaccharide ( LPS) were checked by confocal laser scan and immuno-fluorescence probe indirect labeling techniques. Results It was found that p38 labeled with fluorescence spread all over the cytosol and the nucleus the quiescent cells or cells stimulated by EGF, while the fluorescent intensity reduced in the cytosol area on the stimulation of LPS. Translocation of p38 MAP kinase to the nucleus induced by LPS showed a significant dose-dependent response. Furthermore, it was shown from the dynamics study that the translocation of p38 took place following its activation. On the stimulation of LPS, the kinase activity of p38 reached its peak in 30 min which was followed by a dropping down of kinase activity in 2 h, while the fluorescent intensity in the nuclei of RAW264.7 cells reached its saturated height in 45 min which was thenceforth kept on the high level. Conclusion p38 MAP kinase moved to the nuclei of RAW264.7 cells on the stimulation of LPS, which is a specific response induced by LPS. The translocation of p38 is dependent on its activation by phosphorylation.
出处
《第一军医大学学报》
CSCD
2000年第3期197-201,共5页
Journal of First Military Medical University
基金
国家杰出青年科学基金(39925014)
国家自然科学基金重点(39830400)
面上项目(39800074
39870332)
军队杰出人才基金(98J0
