表皮生长因子受体转激活对氨诱导星形胶质细胞p38MAPK活化的影响

Ammonia induced p38MAPK activation in astrocytes via epidermal growth factor receptor transactivation

目的探讨氨致星形胶质细胞p38MAPK活化与表皮生长因子受体(EGFR)转激活间的关系。方法以3 mmol/L氯化铵刺激原代培养的星形胶质细胞建立高血氨模型,EGFR选择性抑制剂AG1478,src选择性抑制剂PP1及基质金属蛋白酶选择性抑制剂GM6001分别于加入氯化铵前30 min加入,以检测上述信号分子在氨致星形胶质细胞p38MAPK活化中的作用。蛋白质免疫印迹检测p38MAPK的表达及活化,以蛋白质免疫共沉淀检测p38MAPK与EGFR间的相互作用。结果氨诱导的星形胶质细胞p38MAPK活化可被EGFR选择性抑制剂AG1478所阻断,亦可被src选择性抑制剂PP1所阻断,但不受基质金属蛋白酶选择性抑制剂GM6001的影响。对于EGFR-p38MAPK相互作用影响的研究也得出了类似的结果。结论氨刺激可通过EGFR转激活诱导星形胶质细胞p38MAPK的活化。

Objective To investigate the correlation between ammonia - induced activation of p38MAPK and epidermal growth factor receptor（EGFR） transactivation. Methods Primary astrocyte cultures were prepared and challenged by 3 mmol/L NH4Cl to establish a hyperammonemic model. AG1478, which was the selective inhibitor of EGFR, PP1, which was the selective inhibitor of src, or GM6001, which was the selective inhibitor of matrix metalloproteinase, were added 30 min prior to ammonia stimulation. P38MAPK expression and activation were determined by Western blot. The interaction between EGFR and p38MAPK were determined by co-immunoprecipitation. Results Ammonia - induced acti- vation of p38MAPK was abolished by the pretreatment of AG1478, the specific inhibitor of EGFR, and also by PP1, the specific inhibitor of src. This activation, however, was not affected by metalloproteinase specific inhibitor, GM6001. A similar result was seen regarding the interaction between p38MAPK and EGFR. Conclusion Ammonia stimulation can induce p38MAPK activation in astrocytes via EGFR transactivation.